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1 
 
IC 
 
 8906 
 
 Bureau of Mines Information Circuiar/1982 
 
 Mineralogical and Elemental Description 
 of Pacific Manganese Nodules 
 
 By Benjamin W. Haynes, Stephen L. Law, 
 and David C. Barron 
 
 UNITED STATES DEPARTMENT OF THE INTERIOR 
 
Information Circular 8906 
 
 Mineralogical and Elemental Description 
 of Pacific Manganese Nodules 
 
 By Benjamin W. Haynes, Stephen L. Law, 
 and David C. Barron 
 
 UNITED STATES DEPARTMENT OF THE INTERIOR 
 James G. Watt, Secretary 
 
 BUREAU OF MINES 
 Robert C. Norton, Director 
 
4P 
 
 
 }^' 
 
 aO- 
 
 As the Nation's principal conservation agency, the Department of the Interior 
 has responsibility for most of our nationally owned public lands and natural 
 resources. This includes fostering the wisest use of our land and water re- 
 sources, protecting our fish and wildlife, preserving the environmental and 
 cultural values of our national parks and historical places, and providing for 
 the enjoyment of life through outdoor recreation. The Department assesses 
 our energy and mineral resources and works to assure that their development is 
 in the best interests of all our people. The Department also has a major re- 
 sponsibility for American Indian reservation communities and for people who 
 live in Island Territories under U.S. administration. 
 
 This publication has been cataloged as follows: 
 
 Haynes, Denjamln W 
 
 Mineralogical and elemental description of Pacific manganese 
 nodules. 
 
 (Information circular/ Bureau of Mines ; 8906) 
 
 Supt.ofDocs.no.: 128.27:8906. 
 
 1. Manganese nodules— Pacific Ocean. 1. Law, Stephen L. II. 
 Barron, D. C. (David C). III. Title. IV. Series: Information circu- 
 lar (United States. Bureau of Mines) ; 8906. 
 
 TN2957tM- [QE390.2.1V135] 622s [549'. 23] 82-600495 
 
 For sale by the Superintendent of Documents, li.S. Government Printing Office 
 
 Washington, B.C. 20402 
 
J 
 
 
 CONTENTS 
 
 QQ. 
 
 Page 
 
 Abstract 1 
 
 Introduction 2 
 
 Acknowledgments 3 
 
 Manganese nodules 3 
 
 Morphology 3 
 
 Mineralogy 10 
 
 Manganese minerals 11 
 
 Todorokite or 1 A manganite 11 
 
 Birnessite or 7 A manganite 12 
 
 Vernadite or 8-Mn02 12 
 
 Other manganese minerals 13 
 
 Manganese mineral-element associations 13 
 
 Iron oxide minerals 13 
 
 Feroxyhyte 14 
 
 Goethite 14 
 
 Lepidocrocite 14 
 
 Other iron oxide minerals 14 
 
 Iron oxide mineral-element association 14 
 
 Accessory minerals 14 
 
 Sheet silicates and zeolites 14 
 
 Clastic silicates and volcanics 15 
 
 Biogenics 15 
 
 Sea salt residue 15 
 
 Accessory mineral-element associations 17 
 
 Moisture content 17 
 
 Elemental composition 17 
 
 Major and minor elements of potential 
 
 economic interest 17 
 
 Manganese 17 
 
 Iron 18 
 
 Nickel 18 
 
 Copper 18 
 
 Cobalt 23 
 
 Zinc 23 
 
 Page 
 
 Vanadium ?3 
 
 Molybdenum 23 
 
 General observations 28 
 
 Other major and minor elements 28 
 
 Aluminum 28 
 
 Calcium 30 
 
 Magnesium 30 
 
 Potassium 30 
 
 Silicon 30 
 
 Sodium 30 
 
 Strontium 31 
 
 Titanium 37 
 
 Zirconium 37 
 
 General observations 37 
 
 Elements of environmental interest 37 
 
 Arsenic 37 
 
 Barium 40 
 
 Cadmium 40 
 
 Chromium 40 
 
 Lead 40 
 
 Mercury 45 
 
 Selenium 45 
 
 Silver 45 
 
 General observations 45 
 
 Rare-earth elements 46 
 
 Precious-metal-group elements 49 
 
 Radioactive elements 49 
 
 Other trace elements 50 
 
 Anion-forming elements 51 
 
 Summary tables 52 
 
 Cross section analysis 52 
 
 References 57 
 
 Appendix. — Glossary of mineralogical terms 60 
 
 ILLUSTRATIONS 
 
 1 . Map of the Pacific Ocean showing CC Zone and MPS areas 2 
 
 2. Northern Pacific spheroidal nodules with smooth surface texture 4 
 
 3. Study collection of manganese nodules from R/V Prospector 5 
 
 4. Discoidal nodules from box cores 6 
 
 5. Ellipsoidal nodule with large botryoidal surface protrusions and coarse granular surface texture 7 
 
 6. Flat-faced or angular nodules with relatively smooth surface texture 7 
 
 7. Cross section of ellipsoidal Pacific nodule 8 
 
 8. Cross section of north Pacific nodule 9 
 
 9. Contrasting surface textures, smooth and granular, on opposing sides of three nodules 10 
 
 10. Irregular layering with maximum thickness toward bottom of north Pacific nodule 10 
 
 1 1 . Electron microscope observation of todorokite 12 
 
 12. Proposed atomic arrangement for one common todorokite structure 13 
 
 13. Scanning electron photomicrograph showing crystals of the zeolite phillipsite in an oxide 
 
 cavity of a manganese nodule 16 
 
 14. Manganese frequency distribution by environment for Pacific manganese nodules 19 
 
 1 5. Iron frequency distribution by environment for Pacific manganese nodules 20 
 
 16. Nickel frequency distribution by environment for Pacific manganese nodules 21 
 
 17. Copper frequency distribution by environment for Pacific manganese nodules 22 
 
 18. Cobalt frequency distribution by environment for Pacific manganese nodules 24 
 
 19. Zinc frequency distribution by environment for Pacific manganese nodules 25 
 
 20. Vanadium frequency distribution by environment for Pacific manganese nodules 26 
 
 21 . Molybdenum frequency distribution by environment for Pacific manganese nodules 27 
 
 22. Aluminum frequency distribution by environment for Pacific manganese nodules 29 
 
 23. Calcium frequency distribution by environment for Pacific manganese nodules 31 
 
 24. Magnesium frequency distribution by environment for Pacific manganese nodules 32 
 
 25. Potassium frequency distribution by environment for Pacific manganese nodules 33 
 
 26. Silicon frequency distribution by environment for Pacific manganese nodules 34 
 
 27. Sodium frequency distribution by environment for Pacific manganese nodules 35 
 
 \-' 
 
IV 
 
 Page 
 
 28. Strontium frequency distribution by environment for Pacific manganese nodules 36 
 
 29. Titanium frequency distribution by environment for Pacific manganese nodules 38 
 
 30. Zirconium frequency distribution by environment for Pacific manganese nodules 39 
 
 31 . Arsenic frequency distribution for Pacific manganese nodules 40 
 
 32. Barium frequency distribution by environment for Pacific manganese nodules 41 
 
 33. Cadmium frequency distribution by environment for Pacific manganese nodules 42 
 
 34. Chromium frequency distribution by environment for Pacific manganese nodules 43 
 
 35. Lead frequency distribution by environment for Pacific manganese nodules 44 
 
 36. Mercury frequency distribution for Pacific manganese nodules 45 
 
 37. Selenium frequency distribution for Pacific manganese nodules 45 
 
 38. Silver frequency distribution for Pacific manganese nodules 45 
 
 39. Lanthanum frequency distribution for Pacific manganese nodules 46 
 
 40. Cerium frequency distribution for Pacific manganese nodules 46 
 
 41 . Neodymium frequency distribution for Pacific manganese nodules 46 
 
 42. Samarium frequency distribution for Pacific manganese nodules 46 
 
 43. Europium frequency distribution for Pacific manganese nodules 47 
 
 44. Gadolinium frequency distribution for Pacific manganese nodules 47 
 
 45. Terbium frequency distribution for Pacific manganese nodules 47 
 
 46. Holmium frequency distribution for Pacific manganese nodules 47 
 
 47. Thulium frequency distribution for Pacific manganese nodules 48 
 
 48. Ytterbium frequency distribution for Pacific manganese nodules 48 
 
 49. Lutetium frequency distribution for Pacific manganese nodules 48 
 
 50. Hafnium frequency distribution for Pacific manganese nodules 48 
 
 51 . Thorium frequency distribution for Pacific manganese nodules 49 
 
 52. Uranium frequency distribution for Pacific manganese nodules 49 
 
 53. Antimony frequency distribution for Pacific manganese nodules 50 
 
 54. Boron frequency distribution for Pacific manganese nodules 50 
 
 55. Niobium frequency distribution for Pacific manganese nodules 50 
 
 56. Rubidium frequency distribution for Pacific manganese nodules 51 
 
 57. Scandium frequency distribution for Pacific manganese nodules 51 
 
 58. Thallium frequency distribution for Pacific manganese nodules 51 
 
 59. Tin frequency distribution for Pacific manganese nodules 51 
 
 60. Yttrium frequency distribution for Pacific manganese nodules 51 
 
 61 . Unpolished cross section of nodule DH 9-9 55 
 
 62. Spatial distribution of nickel and copper concentrations with respect to discrete sample locations on nodule 
 
 DH 9-9 cross section 56 
 
 63. Spatial distribution of cobalt and zinc concentrations with respect to discrete sample locations on 
 
 nodule DH 9-9 cross section 56 
 
 64. Spatial distribution of iron and lead concentrations with respect to discrete sample locations on 
 
 nodule DH 9-9 cross section 56 
 
 65. Spatial distribution of barium and cerium concentrations with respect to discrete 
 
 sample locations on nodule DH 9-9 cross section 56 
 
 TABLES 
 
 1 . Morphological characteristics of Pacific manganese nodules 4 
 
 2. Manganese minerals in Pacific manganese nodules 11 
 
 3. Iron oxide minerals in Pacific manganese nodules 13 
 
 4. Accessory minerals in Pacific manganese nodules 15 
 
 5. Distribution of elements of potential economic interest in Pacific manganese nodules, by area 18 
 
 6. Distribution of elements of potential economic interest in Pacific manganese nodules, composite 18 
 
 7. Distribution of other major and minor elements in Pacific manganese nodules, by area 28 
 
 8. Distribution of other major and minor elements in Pacific manganese nodules, composite 28 
 
 9. Distribution of elements of environmental interest in Pacific manganese nodules, by area 37 
 
 10. Distribution of elements of environmental interest in Pacific manganese nodules, composite 40 
 
 1 1 . Rare-earth elements in Pacific manganese nodules 47 
 
 12. Precious-metal-group elements in Pacific manganese nodules 49 
 
 13. Radioactive elements in Pacific manganese nodules 49 
 
 14. Other trace elements in Pacific manganese nodules 50 
 
 1 5. Anion-forming elements in Pacific manganese nodules 52 
 
 16. Summary of major, minor, and some trace elements in Pacific manganese nodules, by area 52 
 
 1 7. Summary of elements in Pacific manganese nodules 53 
 
 18. Elements for which no data were found for Pacific manganese nodules 53 
 
 19. Interelement correlation coefficients for Pacific manganese nodules, by area 53 
 
 20. Nodule cross section sample locations and analysis 55 
 
LIST OF UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT 
 
 A 
 
 angstrom 
 
 atm 
 
 atmosphere 
 
 cm 
 
 centimeter 
 
 "C 
 
 degrees Celsius 
 
 m 
 
 meter 
 
 mm 
 
 millimeter 
 
 p.m 
 
 micrometer 
 
 ng/g 
 
 nanograms per gram 
 
 pet 
 
 percent 
 
 pg/g 
 
 picograms per gram 
 
 ppm 
 
 parts per million 
 
 wt-pct 
 
 weight-percent 
 
 yr 
 
 year 
 
MINERALOGICAL AND ELEMENTAL DESCRIPTION 
 OF PACIFIC MANGANESE NODULES 
 
 By Benjamin W. Haynes,' Stephen L. Law,^ and David C. Barron' 
 
 ABSTRACT 
 
 This Bureau of Mines publication comprises a compilation of the state of the science in 
 Pacific Ocean manganese nodule mineralogy and elemental composition. The report is 
 divided into three sections: morphology, mineralogy and elemental composition. 
 
 The nodule morphology section defines what is considered a nodule for the study, and 
 details the external characteristics and internal structure. Nodule mineralogy is discussed 
 in three sections: manganese minerals, iron oxide minerals, and accessory minerals. The 
 major manganese minerals discussed are todorokite, birnessite, and vernadite. The iron 
 oxide minerals are less well known and include feroxyhyte, goethite, and lepidocrocite. 
 Accessory minerals present include quartz, clays, and other silicates and nonsilicates. A 
 discussion on moisture content is also included. 
 
 The elemental composition section presents data on 74 elements occurring as cations or 
 anions. Summary data, histograms, and interelement correlation coefficients are 
 presented. The elements are grouped as follows: major and minor elements of potential 
 economic interest (8), other major and minor elements (9), elements of environmental 
 interest (8), rare-earth elements (15), precious-metal-group elements (6), radioactive 
 elements (3), other trace elements (17), and anion-forming elements (8). Cross sectional 
 determinations of Ni, Cu, Zn, Co, Pb, Fe, Ce, and Ba are given for a single nodule to show 
 the general tendency of different growth patterns within a nodule because of different 
 element associations and composition. 
 
 ' Supervisory research chemist, Avondale Research Center, Bureau of Mines, Avondale, Md. 
 ^ Research supervisor, Avondale Research Center, Bureau of Mines, Avondale, Md. 
 ^ Chemist, Avondale Research Center, Bureau of Mines, Avondale, Md. 
 
INTRODUCTION 
 
 This report is one in a series of reports to be issued by the 
 Bureau of IVIines to document the results of a project entitled 
 "Analysis and Characterization of Manganese Nodule 
 Processing Rejects." Deep seabed mining for manganese 
 nodules, including the processing of nodules to recover value 
 metals, raises a variety of environmental, social, and 
 economic considerations. To address the waste manage- 
 ment aspects of the recovery of value metals from nodules, 
 the National Oceanic and Atmospheric Administration 
 (NOAA) of the Department of Commerce, the Environmental 
 Protection Agency, and the Department of the Interior's 
 Bureau of Mines and Fish and Wildlife Service, after 
 consultation with affected and concerned interests, have 
 agreed to embark on a mulfiyear cooperative research 
 program that has the following overall objective: 
 
 'To provide information needed by Federal and State 
 agencies in preparation for receipt of industry's commer- 
 cial waste management plans." 
 
 The NOAA-funded research being conducted by the 
 Bureau of Mines has the objective of obtaining a "first-order 
 chemical and physical characterization of rejects from the 
 types of manganese nodule processing techniques repre- 
 sentative of those being developed by industry." To better 
 understand the nature of the waste rejects coming from 
 nodule processing, data were first obtained on the mineralog- 
 ical and chemical composition of manganese nodules from 
 throughout the Pacific Ocean, as outlined in this report. After 
 characterization of the nodule feed material, the major 
 proposed processing schemes are being operated on a 
 bench scale to generate rejects for study. These labora- 
 tory-generated rejects will be compared with industry pilot 
 plant-generated rejects as they become available from the 
 various deep ocean mining consortia. 
 
 The data from this research will be published for use by (a) 
 industry and environmental scientists in subsequent re- 
 search to assess the potential effects of waste management 
 alternatives; and (b) regulatory agencies in the determination 
 of standards and test requirements to be met. This is 
 expected to facilitate the development of a basic framework 
 that accommodates the desire to assure protection of the 
 environment and the development of a new minerals 
 processing industry. 
 
 In order to assess the potential effects of disposing of 
 reject waste materials from manganese nodule processing, 
 the elemental composition, the compounds present, the 
 interelement correlations, and the mineralogical structure of 
 manganese nodules must be determined. Because nodules 
 from the Pacific Ocean have higher Cu, Co, and Ni contents 
 than nodules from other areas, this report will focus on the 
 Pacific Ocean manganese nodules 'vith an emphasis on the 
 area between the Clarion and Clipporton Fracture Zones (CC 
 Zone) in the equatorial northeast Pacific (fig. 1). Major 
 consortia involved at this time in deep ocean mining and 
 processing of nodules have extensively surveyed the CC 
 Zone area in the Pacific Ocean. Under the Deep Seabed 
 Hard Minerals Resources Act of 1980 (PL 96-283), NO.AA 
 has been designated as the lead agency in developing terms, 
 conditions, and restrictions for the proposed mining of 
 nodules and the disposal of waste generated. 
 
 This report, focusing on the elemental and mineralogical 
 composition of Pacific Ocean manganese nodules, is divided 
 into the following three sections: 
 
 1 . A description of manganese nodules as they occur in 
 the Pacific Ocean. 
 
 2. Mineralogical composition and element-mineral asso- 
 ciations. 
 
 3. Elemental composition and interelement correlations. 
 
 Figure 1 . — Map of the Pacific Ocean showing CC 
 Zone and IMPS areas. 
 
 The elemental composition is presented for major and 
 some minor and trace elements by areas of the Pacific in the 
 form of histograms. These areas are as follows: 
 
 1 . The Clarion-Clipperton Fracture Zone area. 
 
 2. The mid-Pacific seamounts area (MPS), <3,000-m 
 depth. 
 
 3. Other abyssal plains area (>3,000-m depth and 
 exclusive of CC Zone). 
 
 4. Other seamounts, ridges, and continental margins area 
 (<3,000-m depth). 
 
 The elements for which data were insufficient to be 
 presented by area, are presented as a composite of the 
 Pacific Ocean nodule population. The majority of data for all 
 elements, however, is from the CC Zone owing to 
 commercial interest, abundance, and grade of deposits 
 found there. No data are presented for Indian and Atlantic 
 Ocean nodules. Figure 1 shows the CC Zone and MPS areas 
 of study used in this report. The other two areas comprise the 
 remainder of the Pacific Ocean. 
 
 The mineralogical composition of nodules is presented for 
 the entire Pacific Ocean with some emphasis placed on 
 major mineral differences with respect to environment 
 (depth, sediment type, etc.). The interelement correlations 
 are presented for the major, some minor, and some trace 
 elements where a significant positive or negative correlation 
 was determined. The element-mineral associations are 
 presented for those elements where the evidence is 
 supportive. 
 
 Information and data contained in this report were obtained 
 through many sources. The majority of the elemental and 
 mineralogical information came from the following sources: 
 The Sediment Data Bank, operated by Science Applications, 
 Inc., (SAI) in LaJolla, Calif.; the Bureau of Mines nodule data 
 base at the Denver (Colo.) Research Center; Bureau of 
 Mines in-house research; published literature; other gov- 
 ernmental agencies; private industry and consulting firms; 
 and personal contacts with experts in the field of nodule 
 
chemistry and mineralogy {1-2, 9-10, 12-13, 25-26, 31, 
 38-39, 41-45, 47-50, 60, 63, 67-68, 72, 74, 79-89, 91, 93, 
 95-97, 102, 107, 109-110, 112-114, 118, 121-128, 130-132).' 
 Special mention should be made of the extensive reliance 
 upon the books, Marine Manganese Deposits, edited by G. 
 
 P. Glasby (59); Manganese Nodules, by R. K. Sorem and R. 
 H. Fewkes (117); and Marine Minerals (17), edited by R. G. 
 Burns, for information on the description and mineralogy of 
 Pacific manganese nodules. 
 
 ACKNOWLEDGMENTS 
 
 This work was performed under interagency agreement 
 NA80AAGO 3026 with the Department of Commerce, 
 National Oceanic and Atmospheric Administration (NOAA). 
 The overall research direction and monitoring responsibilities 
 of Amor L. Lane, M. Karl Jugel, and Robert F. Dill, Office of 
 Oceanic fvlinerals and Energy, NOAA, and of Thomas A. 
 Henrie, Chief Scientist, Bureau of Mines, are gratefully 
 acknowledged. 
 
 The authors wish to thank Virginia M. Burns and Roger G. 
 Burns, Massachusetts Institute of Technology, Cambridge, 
 Mass., for their many helpful discussions, comments, and 
 reviews as well as their assistance in providing information 
 
 on newly published articles and also for their assistance in 
 providing scanning electron microscope photomicrographs of 
 nodules. The authors also thank Ronald K. Sorem, 
 Washington State University, Pullman, Wash., for assistance 
 in providing nodule photographs, Ronald H. Fewkes, 
 consultant, Pullman Wash., for manuscript review, Jane B. 
 Frazer, Chevron Research Co., Richmond, Calif., for 
 providing the required information from the Sediment Data 
 Bank, and Allan R. Foster, NORTECH, Kirkland, Wash., and 
 Mike Williamson, consultant, Kirkland, Wash., in providing 
 the cross-sectional analysis. 
 
 MANGANESE NODULES 
 
 Ferromanganese oxides are deposited in a variety of forms 
 in marine environments. In reporting on samples collected by 
 the H.M.S. Challenger expedition (1872-76), Murray and 
 Renard (101) noted hydrates of manganese as "colouring 
 matters, or as thin or thick coatings on shells, corals, shark's 
 teeth, bones, and fragments of rock." There is no universally 
 accepted delineation between objects that are stained or 
 very thinly encrusted with manganese and objects that may 
 be called manganese nodules (59). However, for purposes of 
 chemical comparison of nodules from throughout the Pacific 
 Ocean, a "manganese nodule" will be arbitrarily defined as 
 having a ferromanganese oxide encrustation at least four 
 times greater in bulk than the nucleus object. Otherwise, a 
 nucleus, or multinucleated objects, greater than 20 pet of the 
 total weight will have too significant an influence upon the 
 observed chemistry of the specimen for valid comparisons 
 with manganese nodules having small nuclei. For example, 
 the Drake Passage series of nodules described by Sorem 
 and Fewkes (117) contain rock fragment cores comprising 
 50 pet or greater of the nodule and are therefore not included 
 in the study. Also, it is doubtful that thinly encrusted objects 
 will ever be considered commercially attractive in the same 
 sense as implied in the term "manganese nodule." Of course, 
 if the nucleus of a nodule is a fragment of another nodule, it 
 will be classified as a manganese nodule regardless of 
 nucleus size. 
 
 Manganese micronodules are a special case of the nodule 
 category not included in this study. Micronodules are 
 individual grains generally less than 1 mm in diameter and 
 usually lack a discernible nucleus. Also not included as 
 manganese nodules are the large, slablike concretions such 
 as the manganese pavement from the San Pablo Seamount 
 described by Aumento (6). 
 
 The existence of varying populations of nodules at different 
 localities in the Pacific Ocean can be attributed to several 
 factors including type of nucleation substrate available, 
 bathymetric position, bottom current activity, sediment type, 
 benthic organism activity, and the chemical environment 
 (59). Details of nodule genesis are still poorly understood, 
 though the layering nature and chemical associations 
 characteristic of manganese nodules have been known for 
 many years. 
 
 That nodule formation requires some special conditions is 
 illustrated by the discontinuous distribution of nodule fields 
 and the fact that some fields are rich in Mn, Cu, and Ni 
 whereas others, with essentially the same underlying 
 sediments, are high in Fe and low in Mn, Cu, and Ni. Nodules 
 apparently accrete from both sides, with nickel and copper 
 accreting primarily from the sediment side. Raab and Meylan 
 (59, pp. 109-146) were unable to verify that chemical 
 gradients found in nodules could be ascribed to the upward 
 migration of trace metals owing to diffusion, and their theory 
 on accretion only on the sediment side is no longer accepted 
 by most researchers. Intraplate igneous activity resulting in 
 the extraction and transport of metals from the sediment to 
 the mud-water interface is postulated by Raab and Meylan 
 (59, pp. 109-146) as the source of metals for the concentric 
 layering of nodules. Once the warm, metal-rich brine layer is 
 dissipated, the newly formed nodules are exposed to normal 
 seawater leaching of metals until the next intraplate intrusive 
 event. 
 
 The key to a more complete understanding ot manganese 
 nodule origin lies in the domain of researchers studying the 
 microfeatures and chemical associations in nodules from 
 many areas and is beyond the scope of this report. 
 
 MORPHOLOGY 
 
 Table 1 provides an abbreviated summary of the nature 
 and variability of the morphological characteristics of Pacific 
 
 ■* Italicized numbers in parentheses refer to items in the list of references 
 preceding the appendix. 
 
 manganese nodules. The term morphology is used here in its 
 broadest sense to include not only external shape but also 
 the internal structure of the nodule contributing to the total 
 nodule properties. 
 Figures 2 through 6 show examples of five external 
 
Table 1 Morphological characteristics of Pacific manganese nodules 
 
 Characteristic Nature and extent of variability 
 
 Size Generally 0.5 to 20 cm. Concretions larger than about 20 cm in diameter generally assume the form of slabs. 
 
 External shape Numerous terms used. Most frequent are — 
 
 Spheroidal (peas to cannonballs). 
 
 Ellipsoidal (potatoes). 
 
 Discoidal or tabular (includes slabs). 
 
 Botryoidal, poiylobate, or coalespheroidal (grape cluster). 
 
 Flat faced or polygonal (or irregular shape, owing to angular nucleus or fracturing). 
 
 Surface texture Surfaces are usually mammillated, with texture occurring in two general classifications — 
 
 Smooth: Smooth to the touch and to the eye, though close examination may reveal densely packed minute botryoids. 
 Granular; Feels gritty and may leave tiny oxide particles on the hand upon handling. Close examination may show tiny, 
 
 closely spaced dendritic oxide forms that may be so abundant in some nodules that the surface botryoids are almost 
 
 completely obscured. 
 
 Color Refers to nodule exterior, free of clay. Generally dark reddish brown to black, with variations of black as the most common 
 
 color. 
 
 Crustal zone The outermost layer or set of layers that appear to represent continuous accretion up to the time of collection. Varies from 
 
 well-defined, uniform to asymmetric, to very thin or absent. 
 
 Nucleus Can be any solid object. Often influences external shape of nodule. Examples — 
 
 Rock: Igneous, metamorphic, sedimentary. 
 Nodule fragment. 
 Slab of clay. 
 
 Biological fragment: Tooth, vertebra, bone, fossil, sponges, etc. 
 Volcanic glasses — like pumice, glassy lapilli — almost always profoundly altered. 
 
 No apparent foreign nucleus: fvlay have formed around a nodule fragment with indeterminate laminations, or original 
 nucleus was altered and replaced. 
 
 Internal fractures Generally filled with clay and readily visible in cut nodules. Occasional clay-free fractures lined with overgrowth of 
 
 ferromanganese oxides. Two types — 
 Radial or random: An extension feature having greatest separation toward center of nodule and tapering toward edges. 
 
 Often do not emerge at surfaces but some open toward the sediment side. Show characteristics of shrinkage cracks. 
 Concentric: A fracture along nodule zoning but almost never continuous around entire nodule, frequently terminated by 
 radial fractures. 
 
 Breaks Breakup generally attributed to benthic organisms or bottom currents acting on a fracture-weakened nodule. Terms 
 
 include — 
 Spalling: Peeling of layers, obsen/ed occasionally only in larger nodules (7-cm diam. or larger). 
 Cross section: Transects the nodule layers more or less at right angles; a more common break, 
 a-breaks: Fresh breaks essentially complete before physical recovery from the ocean floor, with the final break 
 
 occurring during handling in a crust holding the nodule together; more common in larger nodules, 
 p-breaks: Old fracture surfaces with entire fracture covered by a crust of manganese material; more common in smaller 
 nodules (<7-cm diam.). 
 
 Interior zoning Some zonal pattern in nodule cross section, produced by variation in mineral content of the growth layers, is generally 
 
 present in all nodules. Three types — 
 Continuous, varied bands: Thicker in one half of the nodule, tapering to a thin portion starting near the equator and 
 becoming very thin at the side opposite the thick portion. Textures and composition of the two portions of tfie band 
 usually differ. 
 Continuous, uniform bands: Often close to the core, suggesting a uniform growth environment. 
 Discontinuous bands: Bands that are completely terminated, usually by sudden tapering near the nodule equator. 
 
 1 
 Scale, cm 
 
 Figure 2. — Northern Pacific spheroidal nodules 
 with smooth surface texture. Latitude 32° 43' N, 
 longitude 158° 15.8 W; depth dredged, 1,120 to 
 
 1 ,400 m. Photograph courtesy of reference 1 17, p. 37. 
 
Scale, cm 
 
 reference 10, p. 493. 
 
Figure 4. — Discoidal nodules from box cores. Side views (a, d); top views (b, e); bottom views (c, f). 
 Botii nodules are from DOMES RP8-OC-76, leg 9. Top nodule is from 151 1.73 N. latitude, 126°03.89 W. 
 longitude at a depth of 4,524 m. Bottom nodule is from 1 5°1 3.04 N. latitude, 1 25°55.94' W. longitude at a 
 
 depth of 4,465 m. Photograph courtesy of reference 1 1 7, p. 39. 
 
 shapes, listed in table 1 , generally exhibited by Pacific 
 manganese nodules — spheroidal, ellipsoidal, discoidal, bot- 
 ryoidal, and flat faced. The shape of a nodule, especially the 
 smaller flat faced nodules, may be influenced by the shape of 
 the nucleus. Table 1 lists the various solid objects that may 
 form the nucleus, and figures 7 and 8 show examples of 
 nuclei. These photographs were taken in reflected light with 
 vertical illumination so that oxides appear bright and clay 
 materials appear dark. 
 
 Figure 9 shows the two general surface textures, smooth 
 or granular, in this case occurring on opposite sides of the 
 same nodules. A different surface texture for the top and 
 bottom of a nodule is not uncommon, especially for the larger 
 asymmetric nodules. 
 
 Nodule size is an important factor because of the 
 relationship between mineralogy and the nodule contact with 
 ocean floor sediments. Accretion of crystalline manganese 
 oxides seems to be enhanced on the portion of the nodule 
 resting in water-saturated, fine-grained silicate sediments. 
 Small nodules (<3-cm diam.), virtually enclosed in soupy 
 sediment, tend to accrete crystalline oxides on all sides and 
 maintain a spheroidal or ellipsoidal shape, or maintain the 
 shape of the nucleus. At a size of about 3 cm or greater, 
 nodules usually tend to develop a pronounced asymmetry of 
 shape because of nonuniform growth rates. The most 
 common pattern is a gradual increase in the horizontal 
 dimensions so that a spheroidal nodule becomes ellipsoidal, 
 and an ellipsoidal nodule approaches a discoidal shape. 
 When the top of the larger nodule comes in contact with 
 relatively sediment-free water, thin iron-rich amorphous 
 oxide layers are slowly added. The bottom and sides of the 
 large nodule, however, remain in contact with watery 
 sediment and continue adding layers of crystalline manga- 
 nese oxides in which fine silicate grains from the substrate 
 are entrapped. 
 
 The accentuated asymmetrical shape of many nodules is 
 due to the more rapid deposition of manganese-rich oxides 
 compared with the amorphous iron-oxide layer growth, and 
 growth of the manganese-rich layers is further enhanced by 
 the incorporation of sediment. The cross-sectional zonal 
 patterns, shown in figure 1 and summarized in table 1 , show 
 the two principal types of growth passing gradationally from 
 one to the other near the equator of the nodule. The 
 photograph in figure 10 was taken in reflected light with 
 vertical illumination so that oxides appear bright and clay 
 materials appear dark. 
 
 The upper surface and the bottom surface of a nodule are 
 usually chemically different from each other and from the 
 nodule interior. The top is generally high in Fe, Co, and Pb 
 and low in Cu, Ni, Mo, Zn, and Mn; the bottom shows the 
 reverse general pattern. The equatorial area of the surface 
 shows intermediate concentrations of the metals. The core of 
 a nodule is often deficient in Fe, Co, and Pb content relative 
 to the crustal surface. However, the zoning within a nodule 
 generally exhibits the same antithetic relationship between 
 manganese content and iron content, and provides further 
 evidence for the different growth process for the top and 
 bottom portions of nodules. This gradational variation in the 
 character, of a layer is called a fades change. The texture of 
 the layer refers to the relationships of the intergrown oxides 
 and nonoxides. The variations in texture are often accompa- 
 nied by variations in thickness of layers. 
 
 With aging, only limited changes seem to occur in the older 
 layers of a nodule. These include the development of 
 shrinkage cracks, both radial and concentric, followed by 
 deposition of oxide veinlets and clay fillings from solutions 
 circulating along the cracks and through pore spaces. The 
 nodule cracking and subsequent physical disturbance may 
 result in breakage of the nodule. As noted in table 1, older 
 fracture surfaces with the entire fracture covered by an oxide 
 
Scale, cm 
 
 Figure 5. — Ellipsoidal nodule with large bot- 
 ryoidal surface protrusions and coarse granular 
 surface texture. Southern Pacific Ocean, latitude 
 
 1 5° S., longitude 90° W. Photograph courtesy of reference 
 117, p. 41. 
 
 Scale, cm 
 
 Figure 6 — Flat-faced or angular nodules with relatively smooth surface texture. Minute botryoids 
 cover left nodule. Botryoids are much larger on the right nodule. Pacific Ocean locations: left, latitude 
 
 15° S., longitude 145° W.; right, latitude 10° S., longitude 150° W. Photograph courtesy of reference 117, p. 41. 
 
*^^ 
 
 Scale, cm 
 
 Figure 7. — Cross section of an ellipsoidal Pacific nodule, latitude 9°59.3' N., longitude 152°56.7' W., 
 from a depth of about 5,000 m, showing a multiple nuclei core: two subround clay fragments, one shark 
 tooth, and one bone fragment. The original nodule enclosed these fragments, was broken, and a 
 
 fragment formed the core of the final nodule. Photograph courtesy of reference 117, p. 253. 
 
Scale, cm 
 
 Figure 8 Nodule cross section of a north Pacific specimen, latitude 11°21.4' N., longitude 153°37.5' 
 
 W., from a depth of 5,190 m, showing the angular fragment of another nodule as the nucleus. Photograph 
 
 courtesy of reference 117, p. 251. 
 
10 
 
 Figure 9 Contrasting surface textures, smooth 
 
 and granular, on opposing sides of tliree nodules 
 (a-d, b-c and c-f) from latitude 10° N., longitude 140° 
 W., at a depth of about 4,500 m. The large nodule is 
 
 approximately 9 cm long. Photograph courtesy of 
 reference 1 1 7, p. 43. 
 
 crust are referred to as p-breaks. Fractures that occur at the 
 time of nodule removal from the ocean floor environment are 
 called a-breaks. 
 
 Scale, cm 
 
 Figure 10. — Irregular layering with ^.he maximum 
 thickness toward the bottom of a north Pacific 
 nodule from latitude 14°35 N., longitude 124°26' 
 
 W., at a depth of about 4,353 m. Photograph courtesy of 
 reference 1 1 7, p. 523. 
 
 Recrystallization and/or replacement of oxides and nonox- 
 ides may be observed to some extent in older nodules, and 
 alteration or even complete replacement of the original 
 nucleus may occur. Basically, however, the mineralogy and 
 most of the textural features in nodule interiors are virtually 
 identical to the outermost layers, indicating that most nodules 
 change little upon aging. 
 
 MINERALOGY 
 
 Manganese nodules consist of a complex mixture of 
 materials, including organic and colloidal matter and nucleus 
 fragments as well as crystallites of various minerals of detrital 
 and authigenic origins. The phases in nodules are fine 
 grained, often metastable, poorly crystallized, and so 
 intimately intergrown that it is often quite difficult to 
 characterize the minute mineral crystallites or to extract a 
 homogeneous, single-phase mineral sample for study. The 
 minerals are usually characterized by numerous structural 
 
 defects, essential vacancies that may not be ordered, 
 domain intergrowths, extensive solid solution, and cation 
 exchange properties that lead to nonstoichiometry and 
 detract from long-range ordering of the crystals. Distin- 
 guishing between authigenic and detrital minerals, particular- 
 ly the silica, clay, and iron oxyhydroxide phases, is also a 
 challenge, as these phases either formed in situ or were 
 transported to the nodule as suspensions in seawater. 
 The major interest in manganese nodules centers on the 
 
11 
 
 oxide minerals of manganese and iron. However, mention 
 will also be made of authigenic and detritai accessory 
 phases. For the purposes of this study, a mineral is defined 
 as an inorganic solid with a crystalline particle size exceeding 
 30 to 40 A, having a limited chemical composition range and 
 a systematic three-dimensional atomic order. The isotropic 
 oxides in manganese nodules are amorphous to X-ray 
 diffraction and cannot be classified usefully by optical means. 
 Particle sizes less than 30 to 40 A are also amorphous even 
 to electron microscopy. These amorphous materials in 
 manganese nodules and other materials lacking an internal 
 structure of atoms are not included as minerals, but are 
 classed as mineraloids. 
 
 Prior to discussion ot the manganese, iron, and accessory 
 mineral phases, it is important to note that much of the work 
 involving the minerals present in manganese nodules is 
 based on laboratory studies using special sampling tech- 
 niques, especially in the case of the iron phase. Standard 
 X-ray diffraction techniques cannot generally determine more 
 than one or two of the manganese and accessory phase 
 minerals. The best results to date have been obtained by 
 scanning and transmission microscope studies. Recent work 
 by Turner (124-126) and Siegel [113) has determined the 
 existence and structure of todorokite in manganese nodules. 
 Chukhrov (34-36) has done research on the iron phases in 
 nodules, but identification is difficult because of the need to 
 preserve the nodule mineralogy once the nodule is removed 
 from the ocean and the potential for dehydration and 
 oxidation of both the manganese and iron phase minerals. 
 
 MANGANESE MINERALS 
 
 Manganese forms a large number of oxide minerals, but 
 only the low-temperature oxides that can be formed in water 
 are relevant to the mineralogy of nodules. The tetravalent 
 manganese predominates in nodules, but the presence of 
 Mn^" and Mn^* ions in some phases has been inferred from 
 crystallographic and thermodynamic data. Table 2 lists the 
 oxide phases of manganese relevant to manganese nodule 
 mineralogy as provided by Burns and Burns (59, pp. 
 185-248). Available crystallographic data, crystal structures, 
 chemical composition, and references to occurrence in 
 nodules are also provided. The mineral listing in table 2 
 follows an approximate order of increasing complexity of 
 crystal structure and decreasing oxidation state of the 
 manganese. 
 
 Todorokite, birnessite, and vernadite are the predominant 
 manganese oxide minerals, occurring as cryptocrystalline 
 phases in manganese nodules. The todorokite and birnessite 
 appear to contain variable linkages of edge-shared [MnOe] 
 octahedra and are characterized by numerous structural 
 defects, cation vacancies in the chains or layers of linked 
 octahedra, domain intergrowths of mixed periodicities, cation 
 exchange properties, and extensive substitution of Ni^, 
 Cu^% Zn^\ Mg^*, or other divalent ions for Mn^". The 
 formation of vernadite, sometimes catalyzed by microorga- 
 nisms, results in a poorly crystalline to amorphous phase with 
 high surface area and cation adsorption properties, concen- 
 trating cobalt by substitution of Co^' for Mn^' (13, 100). 
 Postdepositional rpcrystallization of vernadite to todorokite 
 may occur inside manganese nodules. 
 
 Todorokite or 10-A Manganite 
 
 The manganese oxide mineral characterized by X-ray 
 diffraction lines at 9.5 to 9.8 A and 4.8 to 4.9 A is one of the 
 most common phases observed in manganese nodules. This 
 phase, a hydrated Mn-Mg-Ca-Na-Ni-Cu oxide often with 
 significant concentrations of nickel and copper, has been 
 identified as either todorokite or 10-A manganite. A synthetic 
 structural analog of todorokite also gives a -10- A diffraction 
 peak, but to avoid confusion with the mineral manganite 
 (7-Mn"'00H), this synthetic 10-A manganite phase, called 
 buserite in honor of W. Buser (73), is generally considered 
 not to occur in nodules. 
 
 The chemical formula for todorokite is 
 (Mn^*,Ca,Mg)Mn3''-07-H20 (46). The marine form of todoro- 
 kite found in manganese nodules as adopted by Burns and 
 Burns (17) is (Ca,Na,K)(Mg, Mn^jMns^ Oig-HjO. Most 
 todorokites consist of fibrous aggregates of small acicular 
 crystals. The crystals consist of narrow laths or blades 
 elongated along the b axis (fig. 11) and frequently show two 
 perfect cleavages parallel to the (001) and (100) planes. 
 These fibers are commonly twinned at 120° angles. 
 Chukhrov (31-33) has indicated that as many as five 
 todorokite polymorphs might exist, all having similar b (2.84 
 A) and c (9.59 A) unit cell parameters, but with the a 
 parameters as multiples of 4.88 A. 
 
 Todorokite, both terrestrial and marine, has a tunnel 
 structure with single, double, and triple chains of edge- 
 shared [MnOg] octahedra (31-33, 124-126) along the b axis. 
 Essential Mn^* and other divalent cations of comparable ionic 
 radii (e.g., f^g^^ Co^\ Ni^*, Cu^*, Zn^) may be located in 
 
 Table 2. — Manganese minerals In Pacific manganese nodules 
 
 Mineral 
 
 Approximate formula 
 
 Crystal system and Cell parameters. A 
 
 space group a b c 
 
 Tetragonal. PAs/mnm 4 39 4.39 2.87 
 
 Orthorhombic, Pbnm 4.53 9.27 2.87 
 
 Hexagonal, NA 9.65 NAp 4.43 
 
 (Tetragonal, 14/m 9.96 9.96 2.86 
 
 iMonoclinic, P2,/n 10.03 5.76 9.90 
 
 /Tetragonal, 14/m 9.84 9.84 2.86 
 
 IMonoclinic, 12/m 9.79 2.88 9.94 
 
 fMonoclinic, A2/m 9.56 2.88 13.85 
 
 lOrthorhombic, P2,2,2 8.254 1 3 40 2.864 
 
 Monoclinic, NA 9.75 2.85 9.59 
 
 Hexagonal^ NA 8.41 NAp 10.01 
 
 Triclinia, PI 7.54 7.54 8.22 
 
 Orthorhombic, NA 8.54 15.39 14.26 
 
 Hexagonal, NA 2.84 NAp 7.27 
 
 Hexagonal, NA 2 85 NAp 7.08- 
 
 7.31 
 
 Hexagonal, NA 2.86 NAp 4.7 
 
 Hexagonal 2.84 NAp 7 07 
 
 Orthorhombic, Pbnm 4.56 10.70 2.85 
 
 Monoclinic, B2,/d 8.88 5.25 5.71 
 
 References 
 
 Pyrolusite (p-MnOs) MnOa 
 
 Ramsdellite Mn02 
 
 Nsutite (r-MnOz) (Mn2*,Mn3*,Mn«*) (0,OH)2 
 
 Hollandlte (a-MnOz) (Ba,K)i_2Mn80,6xH20 . . . . 
 
 Cryptomelane Ki_2Mn80,6xH20 
 
 Romanechite (psilomelane) (Ba,K,Mn^*,Co)2 Mn50,oxH20. . . 
 
 Todorokite (Ca,Na,K,Ba,Ag,) (Mg,Mn='\Zn) 
 
 Mn50,2xH20. 
 
 Buserite NaMn oxide hydrate 
 
 Chalcophanite Zn2Mn60i4-6H20 
 
 Synthetic birnessite Na4Mn,4027-9H20 
 
 Do Mn70,3-5H20 
 
 Birnessite (Na,Ca,K) (Mg,Mn) Mn60,4-5H20. 
 
 Vernadite' (&-Mn02) Mn02m(R20.RO,R203)nH20 . . 
 
 Rancieite (Ca,Mn)Mn409-3H20 
 
 Groutite a-MnOOH 
 
 Manganite -y^MnOGH 
 
 2 
 
 4 
 
 NA 
 NA. 
 
 na| 
 
 NA-, 
 
 na| 
 na) 
 
 NA 
 
 NA 
 NA 
 NA 
 NA 
 NA 
 
 NA 
 
 NA 
 
 NA 
 
 70 
 
 52, 56, 90, 1 1 1 
 
 15 
 
 52,56. 103 
 
 4, 8, 70, 98 
 
 3,66.70,72,90, 108, 
 
 116, 119-120, 126 
 7,21,53-58. 106 
 34 
 
 56, 129 
 57 
 7, 18,21,29-30, 37,40, 
 
 58, 64, 70, 90, 108, 
 
 116, 119-120 
 7, 18, 22. 29-30, 106, 
 
 108 
 16, 116 
 63, 103 
 70 
 
 NA Not available. NAp Not applicable 'R = Na, Ca, Co, Fe, Mn. 
 
12 
 
 Figure 11. — Electron microscope observation of todorokite. Photograph courtesy of reference i7. 
 
 specific positions in the chains of edge-shared [MnOe] 
 octahedra. The larger Ca^*, Na , and related group I and II 
 cations, together with water molecules, may occupy the large 
 tunnel structure of todorokite. Some tunnel structures are 
 disrupted by faults along the chain length with the faults 
 going from triple to quadruple chains (126). Marine 
 todorokites have been observed to contain quadruple, 
 quintuple, and larger chains. Figure 12 shows the proposed 
 atomic arrangement of one common structure for todorokite 
 {126). 
 
 Bimessite or 7-A Manganite 
 
 Birnessite in manganese nodules is characterized by X-ray 
 diffraction lines at 7.0 to 7.3 A and 3.5 to 3.6 A. Both sets of 
 lines must be present to establish the presence of birnessite, 
 because hollandite-cryptomelane, zeolites such as phillip- 
 site, and clay-mica groups also have d-spacings around 7 A. 
 The chemical formula for birnessite is Na4Mni4022-9H20 
 (4 6); however. Burns and Burns (17) use 
 (Na,Ca,K)(Mg,Mn)Mn60i4"5H20 as the marine form. The 
 platy habit of birnessite observed by scanning electron 
 microscopy is distinctive. 
 
 The birnessite structure is postulated to contain layers of 
 edge-shared [MnOe] octahedra separated by about 7.2 A 
 along the c axis, which enclose sheets of H2O molecules. In 
 synthetic sodium birnessite, one out of six octahedral sites in 
 the layer of linked [MnOe] is unoccupied. The vacant Mn"* 
 
 sites are distributed according to different patterns for 
 adjacent [MnOe] octahedral layers, resulting in a two-layer 
 orthorhombic cell with periodicity c = 14.26 A. The Mn^" and 
 Mn^* ions are arranged above and below the vacancies, and 
 are bonded with oxygens in both the [MnOe] layer and the 
 sheet of H2O molecules. The structure of sodium-free 
 birnessite has disordered vacancies in the [MnOe] layers, 
 leading to a hexagonal cell with periodicity c = 7.27 A. 
 Divalent cations of Cu, Ni, Co, Zn, etc. are located directly 
 above and below vacancies in the edge-shared [MnOe] 
 octahedral sheets, bound in the birnessite structure rather 
 than randomly adsorbed on external surfaces of the 
 microcrystallites. 
 
 Vernadite or 6-Mn02 
 
 The phase in manganese nodules giving only two diffuse 
 X-ray diffraction lines at 2.40 to 2.45 A and 1 .40 to 1 .42 A is 
 designated as vernadite, a poorly crystalline 8-Mn02 or 
 supergene hydrated manganese (IV) oxide. The chemical 
 composition of vernadite is variable, as reflected in its 
 proposed formula: Mn02-m(R20, RO, R203)-nH20, where R 
 = Na, Ca, Co, Fe, Mn (17). Fleischer (46) lists vernadite as 
 (Mn*%Fe'*,Ca,Na)(0,OH)2-nH20. The iron observed to be 
 present may be an intimately associated or epitaxial 
 intergrowth of feroxyhyte, 6'-FeOOH, rather than a part of the 
 vernadite structure. 
 
 The vernadite is distinguished from a structurally dis- 
 
13 
 
 TODOROKITE 
 
 O • — Manganese 
 
 O • — Oxygen 
 
 (~^ ^^ — Tunnel cations or water molecules 
 
 Figure 12 Proposed atomic arrangement for 
 
 one common todorokite structure. 
 
 ordered birnessite by its distinctive high specific surface area 
 and its significant concentrations of Co, Ca, and Pb. The 
 leaflets of vernadite are tens of angstroms smaller than 
 flakes of birnessite, and are often curved and folded to 
 resemble fibers. 
 
 The vernadite structure is represented as a two-layer 
 hexagonal packing of oxygen atoms and water molecules in 
 which the octahedra are completely filled, but less than half 
 with the tetravalent manganese. The extent of filling by Mn"* 
 is apparently determined by the contents of water and 
 cations other than Mn' * . By inclining leaflets of vernadite with 
 respect to the electron beam, reflections with d spacing equal 
 to 2. 18 to 2.20 A, corresponding to the (101) plane, lead to an 
 approximate c parameter of 4.7 A. This is the approximate 
 width of two layers of close-packed oxygens. 
 
 The poor crystallinity and high specific surface areas of 
 vernadite result in this phase having high cation adsorption 
 properties, particularly tor cobalt. The substitution of low-spin 
 
 Co'* (ionic radius 0.53 A) for Mn"* (0.54 A) in the [MnOe] 
 octahedra of vernadite has been confirmed by photoelectron 
 spectroscopy (100). 
 
 Other Manganese Minerals 
 
 Other manganese minerals that have been reported in 
 manganese nodules are listed in table 2. These include 
 pyrolusite or p-Mn02, ramsdellite, nsutite or 7-Mn02, 
 hollandite or a-MnOg, cryptomelane, romanechite or psi- 
 lomelane, chalcophanite, rancieite, groutite, and manganite. 
 However, they do not appear to be common, and some 
 identifications are not fully accepted. A good discussion of 
 these minerals and others is found in the review by Burns 
 and Burns {15, 17). 
 
 Manganese Mineral-Element Association 
 
 Several elements are associated solely with the man- 
 ganese mineral phase of the nodule. Other elements have 
 been shown to exist with the manganese mineral phase and 
 with the iron or accessory mineral phases. Those elements 
 associated almost entirely with the manganese mineral 
 phase are Cu, Mo, Ni, and Zn. Other elements associated 
 with the manganese phase, but which may be found in other 
 phases also, are Ba, Cd, Ca, Mg, Sb, Sr, and V. 
 
 IRON OXIDE MINERALS 
 
 The oxide, oxide hydroxide (or oxyhydroxide), and 
 hydrated oxide phases of iron relevant to manganese nodule 
 mineralogy are listed in table 3. Included in table 3 are the 
 crystallographic data and some of the literature references to 
 the occurrence of each iron oxide mineral in manganese 
 nodules. As stated earlier, the information to date is based on 
 limited studies, and identification of these iron minerals is 
 difficult because they are extremely fine grained. By analogy 
 with the manganese oxides, the structures of many of the 
 iron oxides consist of close-packed oxygens containing Fe^' 
 and/or Fe^* ions in various octahedral interstices forming 
 different assemblages of edge-shared [FeOe] octahedra. 
 Certain iron (III) oxide hydroxides are isostructural with 
 manganese (IV) oxides, with [FeOe] and [MnOe] octahedra 
 edge-shared in different arrangements. The larger ionic 
 radius of Fe^_compared with Mn' results in larger spacings 
 for the (1010) and (1120) planes of the hexagonal 
 close-packed systems (approximately 2.50 to 2.56 A and 
 1.48 to 1.54 A, respectively), and Fe-Fe interatomic 
 distances across edge-shared [Fe(0,0H)6] octahedra range 
 from 2.95 to 3.05 A. The most commonly observed 
 iron-bearing minerals in manganese nodules, to be discus- 
 sed in more detail, are goethite, lepidocrocite, and feroxy- 
 hyte. Other iron minerals observed include akaganeite, 
 ferrihydrite, hematite, magnetite, and maghemite. 
 
 Table 3. — Iron oxide minerals in Pacific manganese nodules 
 
 Mineral 
 
 Goethite (a-FeOOH 
 
 Akaganeite (p-FeOOH) 
 
 Lepidocrocite (7-FeOOH) 
 
 Hydrated oxyhydroxide 
 polymer (synthetic). 
 
 Ferrihydrite 
 
 Feroxyhyte (fi'-FeOOH) 
 
 Hematite (u-FesOs) 
 
 Maghemite (^'-FejOs) 
 
 Magnetite (spinel) 
 
 NA Not available. NAp Not applicable 
 
 Approximate formula 
 
 Crystal system and 
 space group 
 
 Cell parameters, A 
 
 References 
 
 FeOOH Orthorhombic, Pbnm 4.65 
 
 (OH,CI,H20),^2 Fe8(0,OH),6 . . Tetragonal, 14/m 10.48 
 
 FeOOH Orthorhombic, Amam 3.88 
 
 rFeO,3_,| 2(0H), Hexagonal. NA 5.88 
 
 lFe5H08-4H20 Hexagonal, NA 5.08 
 
 SFesOa-SHaO Hexagonal, NA 5,08 
 
 FeOOH Hexagonal. NA 2 93 
 
 Fe203 Hexagonal, R3c 5,04 
 
 FesOs /Cubic, P2,3 8,32 
 
 iTetragonal, P4,2,2 8.338 
 
 Fe304 Cubic, Fd3m 8.39 
 
 10,02 
 10.48 
 12.54 
 NAp 
 NAp 
 NAp 
 NAp 
 NAp 
 8.32 
 
 3.04 
 3,028 
 3.07 
 9.4 
 9,4 
 9,4 
 4,60 
 13,77 
 8,32 
 
 8 338 25,014 
 839 8,39 
 
 4 
 
 1 
 
 4 
 
 NA 
 NA 
 NA 
 
 1 
 
 6 
 
 S) 
 NAJ 
 
 8 27 
 
 22, 27, 51. 62, 78 
 61 
 
 27, 35, 51, 62, 78 
 71, 75-77 
 
 28, 129 
 23 
 36 
 69 
 27, 62, 
 
 129 
 
14 
 
 Feroxyhyte 
 
 Feroxyhyte is considered to be a polymorph with 
 akaganeite, goethite, and lepidocrocite and has a formula of 
 8'-FeOOH (36). The structure is thought to be a hexagonal 
 close packing of oxygen and differs only from 8-FeOOH by 
 the arrangement of the iron atoms. Feroxyhyte is found as 
 yellow-brown plates in admixtures of clay minerals and 
 goethite. Its strongest diffraction lines are 2.54 and 2.23 A, 
 with other lines at 1 .69 and 1 .47 A {36). 
 
 As a magnetically disordered form of 8-FeOOH, no 
 reflection characterizing an ordered distribution of Fe^* in the 
 octahedral sites is observed in electron diffraction patterns 
 from feroxyhyte. Feroxyhyte is unstable in air and transforms 
 to goethite {99). 
 
 Goethite 
 
 Goethite (a-FeOOH) is the polymorph to which most other 
 FeOOH phases revert upon aging. It is isostructural with the 
 manganese minerals ramsdellite and groutite, consisting of 
 double chains of [Fe(0,0H)6] octahedra linked together by 
 sharing opposite edges. An octahedron from one chain 
 shares an edge with two octahedra from another chain, and 
 the double chains are further crosslinked to adjacent double 
 chains through double sharing of oxygen, producing an 
 orthorhombic symmetry. The goethite in this structure occurs 
 in a habit of acicular needles, 0.1 to 1.0 (xm in length. The 
 iron atoms occupy only octahedral positions in this yellow- 
 brown colored mineral {99). 
 
 Goethite is an antiferromagnetic mineral, that is, goethite 
 remains magnetized even when a magnetic field is removed. 
 The magnetization is not reversible. High CI concentrations 
 in seawater should inhibit the formation of goethite. Thus, the 
 widely reported occurrence of goethite in nodules may result 
 from the fact that it is the end product of both hydrolysis and 
 oxidation action in the other FeOOH phases {99). 
 
 Lepidocrocite 
 
 The abundance of reported lepidocrocite (7-FeOOH) 
 appears to indicate a relatively rapid oxidation of Fe(ll) 
 solutions, though it may occasionally form from Fe(lll). 
 Lepidocrocite has a cubic close-packed oxygen lattice 
 structurq with no structural analogs among the manganese 
 oxides or hydroxide phases. The iron atoms occupy only 
 octahedral positions in the stacking of oxygen-hydroxyl 
 planes along the [051] direction. This orange-colored mineral 
 forms lath-shaped crystals ranging from 0.5 to 1 .0 ixm long 
 199). 
 
 Lepidocrocite is neither ferrimagnetic nor antiferromagne- 
 tic (see appendix) at ordinary temperatures, and so it carries 
 no magnetic remnants. It is transformed to maghemite at 
 250° to 300° C. 
 
 Other Iron Oxide Minerals 
 
 Akaganeite (p-FeOOH) is the form of iron that precipitates 
 from Cl-rich solutions such as seawater. The failure to 
 identify akaganeite more frequently in nodules may be the 
 result of rapid conversion to the more stable goethite under 
 seawater conditions, though akaganeite has been shown to 
 be stable for up to 2 yr at pressures up to 1,000 atm {99). 
 Also, the cryptocrystallinity of akaganeite may have resulted 
 in the mineral being amorphous to X-ray diffraction, or 
 phases identified as phillipsite may have actually been 
 mixtures of goethite and akaganeite (99). 
 
 Magnetite (Fe304) and maghemite (7-Fe203) result from 
 relatively slow oxidation of Fe(ll) solutions, and can form 
 authigenically in the ferromanganese nodules. Hematite can 
 crystallize from the seawater dissolution of fine-grained 
 goethite or by dehydration of the goethite, but environmental 
 conditions may result in the formation of both minerals by 
 
 separate pathways. Hematite, once formed, does not appear 
 to rehydrate to form goethite. Hematite is also formed by the 
 aggregation of small ferrihydrite particles followed by 
 nucleation and crystallization of hematite. Ferrihydrite also 
 serves as a source of dissolved iron for the crystallization of 
 goethite. 
 
 Iron Oxide Mineral-Element Association 
 
 Several elements are associated solely with the iron oxide 
 phase of the nodule. Other elements have been shown to 
 exist in iron oxide mineral phases and with manganese or 
 accessory mineral phases. Those elements associated 
 almost entirely with the iron oxide phase are Pb and Ti with 
 Co occurring in both the iron and manganese phase 
 depending on the oxidation-reduction potential of the 
 seafloor (generally related to depth). Other elements 
 associated with the iron phase, but which may also be found 
 in other phases, are Ce, Co, Sr, V, and Zr. 
 
 ACCESSORY MINERALS 
 
 The accessory minerals found in Pacific manganese 
 nodules can be divided into the following three general 
 categories: 
 
 1 . Sheet silicates and zeolite minerals. 
 
 2. Clastic silicate and volcanic minerals. 
 
 3. Biogenic minerals. 
 
 These minerals are poorly defined in manganese nodules 
 because most exist as fine-grained crystallites similar to the 
 manganese- and iron-phase minerals. Some of these 
 accessory minerals were identified in the residues of acid 
 leached nodules. This acid leaching tends to concentrate, 
 and potentially recrystallize and/or flocculate these minerals 
 together with the iron-phase minerals while dissolving the 
 manganese-phase minerals. Because of their low concen- 
 trations in nodules, the accessory minerals are often not 
 detected by X-ray diffraction methods on bulk samples. 
 Some minerals have been identified by selective area 
 electron diffraction. 
 
 Although most published studies on manganese nodules 
 do not address the accessory minerals, some of these 
 minerals may be necessary for the nucleation and growth of 
 the iron and manganese oxides. Quite often, the core or 
 nucleus of nodules consists of volcanic rock fragments, 
 glass, shark teeth, fish bones, or siliceous and calcareous 
 remains of marine organisms. Table 4 lists the various 
 accessory minerals, their formulas, cell parameters, crystal 
 system, and references where they were reported. 
 
 Sheet Silicates and Zeolites 
 
 Several sheet silicates and zeolites have been reported in 
 manganese nodules. The clay found in nodules are those 
 associated with the sediments where the nodules were 
 formed {19-20), and are fine-grained hydrous aluminum 
 silicates probably formed by submarine alteration of the 
 primary minerals in basalts. The sheet silicates reported in 
 nodules are chlorite, illite, kaolinite, montmorillonite, nontro- 
 nite, pyrophyllite, and talc. The common clay present is 
 generally montmorillonite. These minerals in nodules occur 
 probably from inclusion of the sediments during nodule 
 growth. 
 
 The zeolites found in nodules are authigenic and are found 
 in cracks and cavities in the interior of nodules. The zeolites 
 are hydrous silicates with a very open framework and large 
 interconnecting spaces or channels that are filled with 
 sodium, calcium, and variable amounts of water. The zeolites 
 reported in nodules are analcite, clinoptilolite, epistilbite, 
 erionite, mordenite, and phillipsite. The most commonly 
 reported zeolite is phillipsite whereas the remaining zeolites 
 
15 
 
 Table 4. — Accessory minerals in Pacific manganese nodules 
 
 Mineral group and mineral 
 
 Formula 
 
 Crystal system and 
 space group 
 
 Cell parameters, A 
 
 References 
 
 SILICATES 
 
 Tectosilicates: 
 Zeolites: 
 
 Analcite NaAISi206H20 Isometric, Ia3d 13.72 
 
 Clinoptilolite (Na,K,Ca)2-3Al3(AI,Si)2Si,3036-12H20 Monoclinic, 12/m 15.85 
 
 Epistilbite CaAlsSigOis-SHsO Monoclinic. NA 8.92 
 
 Erionite (Ca,Na,K,Mg)5Al9Si27072-27H20 Hexagonal, PSa/mmc 13.26 
 
 Mordenite (Ca,N'a2,K2)4AleSi4o096-28H20 Orthorhombic, Cmcm 18.13 
 
 Phillipsite KCa(Al3Si50,6)-6H20 Orthorhombic, B2mb 
 
 Do Kj aNa, eAU 4S1, , 6032-1 OH2O Monoclinic, P2, or P2i/m . 
 
 K-feldspar (orthoclase) KAISijOg Monoclinic, C2/m 
 
 Labradorite (feldspar) Ab^oAnso^^^-AbsoAnyo Triclinic, NA 
 
 Plagioclase (feldspar) (Na,Ca)AI(Si,AI)Si208 Triclinic, NA 
 
 Sanidine (feldspar) KAISi308 Monoclinic, C2/m 
 
 Quartz 8102 Hexagonal, P3221-P3,21 
 
 9.96 
 10.02 
 8.56 
 8.17 
 8.14 
 8.56 
 4.91 
 
 Phyllosilicates: 
 
 Chlorite (Mg,Fe)3(Si,AI)40,o(OH)2(Mg,Fe)3(OH)6 Monoclinic, C2/m 5.2 
 
 lllite General term for mica-like clays NAp NAp 
 
 Kaolinite Al2Si205(OH)4 Triclinic, PI 5.14 
 
 Montmorillonite (AI,Mg)8(Si40,o)3(OH)io-12H20 Monoclinic, C2/m 5.23 
 
 Nontronite Fe2(AI,Si)40io(OH)2Nao 3(H20)4 M loclinic, NA . 
 
 5.23 
 
 Pyrophyllite Al2Si40,o(OH)2 Monoclinic, C2/c 5.16 
 
 Talc Mg3Si40io(OH)2 Monoclinic, C2/c 5.27 
 
 Biotite (mica) K(Mg,Fe)3(AISi30,o)(OH)2 Monoclinic, C2/m 5.31 
 
 Prehnite Ca2AI(AISi30,o)(OH)2 Orthorhombic, P2c/m 4.65 
 
 Stilpnomelane K(Fe,Mg,AI)3Si40,o(OH)2xH20 Monoclinic, NA 5.40 
 
 Inosilicates (double chain): 
 
 Hornblende (amphibole) . . . (Ca,Na)2-3(Mg,Fe,AI)5Si6(SiAI)2022(OH)2 Monoclinic, C2/m 9.87 
 
 Inosilicates (single chain): 
 
 Augite (pyroxene) (Ca,Na)(Mg,Fe,AI)(Si,AI)206 Monoclinic, C2/c 9.73 
 
 Nesosilicates: Olivine (Mg,Fe)2Si04 Orthorhombic, Pmcn 4.76- 
 
 4.82 
 
 Other silicates: 
 
 Opal (amorphous) Si02-nH20 NAp NAp 
 
 Titanite (sphene) CaTiOOiOs) Monoclinic, C2/c 6.56 
 
 13.72 
 17.89 
 17.73 
 NAp 
 20.49 
 14.25 
 14.28 
 12.96 
 12.85 
 12.84 
 13.03 
 NAp 
 
 9.2 
 
 NAp 
 
 8.93 
 
 8.93- 
 
 9.00 
 
 9.10- 
 
 9.12 
 
 8.88 
 
 9.12 
 
 9.23 
 
 5.48 
 
 9.42 
 
 18.01 
 
 13.72 
 7.41 
 
 10.21 
 
 15.12 
 7.52 
 
 14.25 
 8.64 
 7.21 
 7.13 
 7 16 
 7.17 
 5.41 
 
 28.6 
 NAp 
 7.37 
 
 29.8 
 
 NA 
 
 18.64 
 18.85 
 10.18 
 18.49 
 12,14 
 
 5.33 
 
 16 
 4 
 3 
 
 NA 
 
 4 
 
 4 
 
 NA 
 8 
 4 
 3 
 
 4 
 NAp 
 
 2 
 NA 
 
 NA 
 
 2 
 
 4 
 2 
 2 
 1 
 
 8.91 5.25 
 
 10.20- 
 10.48 
 
 NAp 
 8.72 
 
 5.98- 
 6.11 
 
 NAp 
 7.44 
 
 NAp 
 4 
 
 70 
 94 
 94 
 94 
 
 3, 94 
 
 3-4, 11, 65, 
 104-106, 115 
 
 11, 22, 115 
 
 11 
 
 94, 115 
 
 94 
 
 5, 11, 22, 24, 62, 
 70, 104-106, 
 115, 121 
 
 4, 1 1 , 24 
 94, 115, 121 
 106, 115 
 
 3-4, 6, 11, 58, 65, 
 94, 105, 129 
 
 5, 11, 93, 106 
 
 94 
 94 
 93 
 94 
 106 
 
 5,93 
 
 5,11, 70, 93-94, 
 
 106 
 11, 94 
 
 5, 93 
 14 
 
 NONSILICATES 
 
 Volcanics: 
 
 Anatase Ti02 
 
 Barite BaS04 
 
 Ilmenite FeTiOs 
 
 Magnetite (spinel) (Fe,Mg)Fe204 
 
 Rutile Ti02 
 
 Biogenics: 
 
 Apatite Ca5(P04)3(F,CI,0H). 
 
 Aragonite CaCOs 
 
 Calcite CaCO, 
 
 . Tetragonal, 14,/amd 3.78 3.78 9.51 4 5, 70, 93 
 
 . Orthorhombic, Pnma 8.87 5.45 7.14 4 5, 70, 93 
 
 . Hexagonal, R3 5.09 NAp 14.06 6 94 
 
 . Isometric, Fd3m 8.40 8.40 8.40 8 94 
 
 . Tetragonal, P42/mnm 4.59 4.59 2.96 2 5, 70, 93 
 
 . Hexagonal, P63/m 9.39 NAp 6.89 2 4-5, 9, 90 
 
 . Onhorhombic, Pmcn 4.95 7.96 5.73 4 92 
 
 . Hexagonal, R3c 4.99 NAp 1 7.06 6 72, 90 
 
 NA Not available. NAp Not applicable. 
 
 are rare with some question of their proper identification. 
 Phillipsite, because of its delicate euhedral crystal habit and 
 its occurrence in the leached interior cavities of nodules 
 appears to have formed authigenically (fig. 13). Phillipsite 
 crystals in some nodules appear to have grown together with 
 some of the manganese oxide phase minerals, particularly 
 todorokite (19-20). 
 
 Clastic Silicates and Volcanics 
 
 Many silicate minerals and some volcanic minerals have 
 been observed in manganese nodules. They consist of 
 individual grains of clastic sediments of various minerals that 
 may form the core or become incorporated into the nodule 
 during nodule growth. The clastic silicate (detrital) minerals 
 observed in nodules are given in table 4. The more common 
 minerals present are quartz and various feldspars. One 
 mineral, opal, is believed to have formed authigenically. The 
 volcanic minerals reportedly observed in manganese 
 nodules are barite, magnetite (spinel), and the titanium- 
 containing minerals, anatase, ilmenite, rutile, and sphene. 
 
 Biogenics 
 
 The biogenic minerals found in manganese nodules come 
 from the debris of dead organisms, such as bones and teeth 
 of fish, sharks, and whales, and the siliceous remains of the 
 zooplankton radiolaria. The larger debris such as bones and 
 teeth are generally associated with the cores of nodules 
 whereas the radiolaria remains are observed throughout the 
 nodules. These radiolaria remains are probably incorporated • 
 from the sediment as the nodule grows. The debris in the 
 interior of the nodule may undergo dissolution and may be 
 associated with the formation of phillipsite and todorokite. 
 The minerals of biogenic origin are apatites, primarily from 
 bones and teeth; aragonite and calcite, from the shells of 
 various animals; and opal, which may also be derived from 
 radiolaria. 
 
 Sea Salt Residue 
 
 f^inerals in dried nodules that are the result of seawater 
 evaporation are sylvite, halite, and other common evaporites 
 
16 
 
 Figure 1 3. — Scanning electron photomicrograph showing crystals of the zeolite phillipsite in an oxide 
 
 cavity off a manganese nodule. Photograph courtesy of reference 117, p. 60. 
 
17 
 
 present in dissolved form in seawater. These residues are 
 also the primary source of the anions — borate, bromide, 
 chloride, fluoride, and iodide — in manganese nodules. 
 
 Accessory Mineral- 
 Element Association 
 
 Several elements are associated solely with the accessory 
 minerals of the nodule. Other elements have been shown to 
 exist in accessory minerals and with the iron oxide or 
 manganese phases. Those elements associated almost 
 entirely with the accessory minerals are Al, Cr, K, P, and Si. 
 
 Other elements associated with the accessory minerals and 
 possibly other phases are Ba, Mg, Na, and Zr. 
 
 MOISTURE CONTENT 
 
 Water in manganese nodules comprises about 45 to 50 
 wt-pct of the nodule when removed from the sea. Drying in air 
 removes approximately half of the water. Drying at 110° C 
 reduces the moisture content of nodules to approximately 5 
 to 10 wt-pct. Thermal gravimetric analysis in the temperature 
 range of 110° to 1,200° C indicates that the 5 to 10 wt-pct 
 water is bound in the crystal structure. 
 
 ELEMENTAL COMPOSITION 
 
 The elemental characterization of Pacific manganese 
 nodules is a topic addressed by many authors. Major 
 element composition of these nodules is well established, 
 whereas data on many minor and most trace elements are 
 limited. This section summarizes available data on most of 
 the naturally occurring elements, and where data are 
 sufficient, gives ranges, means, medians, and number of 
 samples. In the case of the major, most minor, and some 
 trace elements, the data are divided into four distinct areas of 
 the Pacific Ocean floor. 
 
 1. The Clarion-Clipperton Fracture Zone area (CC-Zone 
 area). 
 
 2. The mid-Pacific seamounts area (MPS area), <3,000- 
 m depth. 
 
 3. Other abyssal plains area >3,000-m depth, and 
 exclusive of CC-Zone area. 
 
 4. Other seamounts, ridges, and continental margins area 
 (<3,000-m depth). 
 
 For these elements, histograms and comparison tables are 
 presented for the different areas to show variations of these 
 elements by area. Where a paucity of data exists for the 
 remaining elements, histograms, and tables are presented 
 for the composition based on the total Pacific Ocean, In some 
 cases, data are so limited (<40 sample analyses) that no 
 histogram is presented. Nodules from the Drake Passage 
 area of the Pacific and most of the ocean area directly south 
 of Australia have also been omitted. The Drake Passage 
 nodules are omitted because of their tendency to contain 
 large rock fragments as nuclei, thereby making their bulk 
 chemical analysis atypical of the other Pacific nodules. The 
 area south of Australia is the southeast portion of the Indian 
 Ocean and therefore is not considered part of the Pacific 
 Ocean. 
 
 The data for the elements are broken down into eight 
 groups based on either their chemistry or special interest. 
 The groups of elements are presented in the following order: 
 
 1. Major and minor elements of potential economic 
 interest (Mn, Fe, Ni, Cu, Co, Zn, V, Mo). 
 
 2. Other major and minor elements (Al, Ca, Mg, K, Si, Na, 
 Sr, Ti, Zr). 
 
 3. Elements of environmental interest (As, Ba, Cd, Cr, Pb, 
 Hg, Se, Ag). 
 
 4. Rare-earth elements (lanthanides) (La, Ce, Pr, Nd, Sm, 
 Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf). 
 
 5. Precious-metal-group elements (Au, Ir, Pd, Pt, Re, Ru). 
 
 6. Radioactive elements (Ra, Th, U). 
 
 7. Other trace elements (Sb, Be, Bi, B, Cs, Ga, Ge, Li, 
 Nb(Cb), Rb, Sc, Ta, Te, TI, Sn, W, Y). 
 
 8. Anion-forming elements (Br, C, CI, F, I, N, P, S). 
 
 Within the first three groups, each element is discussed 
 briefly; the chemical form of occurrence in nodules is given if 
 
 known, and for 21 elements listed within the first three 
 groupings (exclusive of Ag, As, Hg, and Se), interelement 
 correlations are presented by area where data are sufficient. 
 The interelement correlation coefficients (presented in table 
 19) are results of linear regression analysis with the 
 correlation coefficients varying from - 1 to + 1 . Correlations 
 with values >0.3 and <-0.3 were considered significant 
 positive or negative correlations. Of the naturally occurring 
 elements (exclusive of inert gases and hydrogen), no data 
 were obtained for the following elements: Rh, In, Pm, Os, Po, 
 At, Fr, Ac, and Pa. Oxygen is not discussed specifically but is 
 the major combining form for most elements. All concentra- 
 tions are reported on a dry-weight basis. The majority of the 
 information contained in these sections was obtained from 
 the Sediment Data Bank (48), as compiled by Frazer with 
 information from Frazer (44, 48-50), Sorem (118), Fewkes 
 (42-43), and Monget (97). 
 
 MAJOR AND MINOR ELEMENTS OF 
 POTENTIAL ECONOMIC INTEREST 
 
 The elements in this section are those major and minor 
 elements that are of potential economic interest. The eight 
 elements are Mn, Fe, Ni, Cu, Co, Zn, V, and Mo. Because of 
 the amount of data available, the concentrations of these 
 elements are divided into the four areas of the Pacific 
 previously mentioned. Table 5 is a breakdown, by element, 
 for the four areas, and gives range, median range, arithmetic 
 mean, standard deviation of the mean, and the number of 
 samples used for the statistical base. Table 6 gives 
 composite data for those elements from Pacific nodules. The 
 overall mean in table 6 is calculated based on the number of 
 data points for each element in each area and the respective 
 concentrations. 
 
 Manganese 
 
 Manganese concentrations in Pacific nodules vary from 1 
 to 40 wt-pct, with a median range of 16 to 27 wt-pct, and 
 weighted mean of 21.6 wt-pct based on 5,079 sample 
 analyses. The median value for CC-Zone area nodules is the 
 highest of all other areas at 26 to 27 wt-pct with a mean of 
 25.4 wt-pct. Nodules from the other three areas are much 
 lower with a median range of 1 6 to 21 wt-pct and much higher 
 iron values. Figure 14 provides histograms that show 
 manganese distribution in each of the four areas. 
 
 Manganese occurs in Pacific nodules as several minerals, 
 all oxides and hydrated oxides. These minerals are 
 todorokite, birnessite, and vernadite (S-MnOg). A discussion 
 of these and other forms of manganese is given in detail in 
 the "Mineralogy" section. 
 
 Manganese in the CC-Zone area is positively correlated 
 
Table 5 Distribution off elements off potential economic interest in Paciffic manganese nodules, by 
 
 area, weight-percent 
 
 Area 
 
 Range 
 
 Median 
 
 Mean, 
 
 Standard 
 
 deviation of 
 
 mean, ctx 
 
 Number of 
 samples 
 
 Range 
 
 Median 
 
 Mean, 
 
 X 
 
 Standard 
 
 deviation of 
 
 mean, o-x 
 
 Number of 
 samples 
 
 Clarlon-Cllpperton zone 
 
 MId-PaclfIc seamounts 
 
 Other abyssal plains, >3,000 m. 
 Other seamounts, ■<3, 000 m . . . 
 
 Clarlon-Clipperton zone 
 
 MId-PaclfIc seamounts 
 
 Other abyssal plains, >3,000 m. 
 Other seamounts, < 3,000 m . . . 
 
 Clarlon-Cllpperton zone 
 
 Mid-Pacific seamounts 
 
 Other abyssal plains, >3,000 m. 
 Other seamounts, <3,000 m . . . 
 
 Clarlon-Cllpperton zone 0.10- 2.00 
 
 MId-PaclfIc seamounts <.01- 1 .00 
 
 Other abyssal plains, >3,000 m. . . . <.05- 2.00 
 
 Other seamounts, <3,000 m <.05- 1.20 
 
 
 
 
 
 Manganese 
 
 
 
 
 
 
 
 Cobalt 
 
 
 
 1 
 
 -39 
 
 26 
 
 -27 
 
 
 25.4 
 
 4.9 
 
 2,227 
 
 <0.10-0.90 
 
 0.20-0.30 
 
 0.24 
 
 0.08 
 
 1,925 
 
 1 
 
 -40 
 
 20 
 
 -21 
 
 
 20.8 
 
 8.1 
 
 183 
 
 <. 10-2.50 
 
 .70- 
 
 .80 
 
 .76 
 
 .45 
 
 182 
 
 1 
 
 -40 
 
 18 
 
 -19 
 
 
 18.5 
 
 7,2 
 
 2,354 
 
 <. 10-1 .40 
 
 .20- 
 
 .30 
 
 .24 
 
 .17 
 
 2,219 
 
 1 
 
 -40 
 
 16 
 
 -17 
 
 
 17.8 
 
 8.6 
 
 315 
 
 <. 05-1 .40 
 
 .20- 
 
 .30 
 
 .31 
 
 .27 
 
 293 
 
 Iron 
 
 Zinc 
 
 1 
 
 -25 
 
 6 
 
 - 7 
 
 
 6.9 
 
 2.6 
 
 2,215 
 
 <0.05 -0.95 
 
 0.10-0.15 
 
 0.14 
 
 0.05 
 
 1,539 
 
 2 
 
 -25 
 
 14.5 -15.5 
 
 14.7 
 
 4.1 
 
 185 
 
 <.05 - 
 
 .25 
 
 .05- 
 
 .10 
 
 .07 
 
 .03 
 
 82 
 
 1 
 
 -25 
 
 12 
 
 -13 
 
 
 12.7 
 
 5.1 
 
 2,325 
 
 <.05 - 
 
 .95 
 
 .05- 
 
 .10 
 
 .09 
 
 .1 
 
 1,285 
 
 1 
 
 -25 
 
 16 
 
 -17 
 
 
 15.6 
 
 6.4 
 
 312 
 
 <.05 - 
 
 .55 
 
 .05- 
 
 .10 
 
 .07 
 
 .05 
 
 191 
 
 Nickel 
 
 Vanadium 
 
 0.10- 2.00 
 
 1.30- 1.40 
 
 1.28 
 
 0.30 
 
 2,237 
 
 <0.005-0.08 
 
 0.04-0.05 
 
 0.047 
 
 0.048 
 
 70 
 
 
 10- 1.50 
 
 
 40- 
 
 50 
 
 .49 
 
 .24 
 
 188 
 
 <.005- 
 
 .30 
 
 .07- 
 
 .08 
 
 .086 
 
 .087 
 
 29 
 
 
 10- 2.00 
 
 
 50- 
 
 60 
 
 .63 
 
 .40 
 
 2,334 
 
 <.010- 
 
 .30 
 
 .04- 
 
 .05 
 
 .048 
 
 .025 
 
 370 
 
 
 10- 1.30 
 
 
 30- 
 
 40 
 
 .35 
 
 .24 
 
 315 
 
 <.005- 
 
 .14 
 
 .06- 
 
 .07 
 
 .067 
 
 .028 
 
 38 
 
 Copper 
 
 Molybdenum 
 
 1.00-1.10 1.02 
 
 <.05 .10 
 
 .30- .40 .42 
 
 <.05 .11 
 
 0.33 
 .10 
 .32 
 .14 
 
 2,236 
 176 
 
 2,282 
 304 
 
 <0.005-0.12 0.05-0.06 0.052 0.018 265 
 
 <.005- .11 .05- .06 .052 .022 56 
 
 <.005- .13 .03- .04 .036 .021 746 
 
 <.005- .15 .03- .04 .050 .067 88 
 
 Table 6. — Distribution off elements of potential 
 
 economic interest in Paciffic manganese 
 
 nodules, composite, weight-percent 
 
 Element 
 
 Range 
 
 Range of 
 medians 
 
 Weighted 
 mean 
 
 Number of 
 samples 
 
 Manganese 1 -40 
 
 Iron 1 -25 
 
 Nickel 1 - 2.0 
 
 Copper < .01 - 2.0 
 
 Cobalt < .05 - 2.5 
 
 Zinc < .05 - .95 
 
 Vanadium < .005- .30 
 
 Molybdenum < .005- .15 
 
 16 -27 
 
 21.6 
 
 5,079 
 
 6 -17 
 
 10.4 
 
 5,037 
 
 .3 - 1.4 
 
 .9 
 
 5,074 
 
 .05- 1.10 
 
 .66 
 
 4,998 
 
 .2 - .8 
 
 .26 
 
 4,619 
 
 .05- .15 
 
 .11 
 
 3,097 
 
 .04- .08 
 
 .05 
 
 507 
 
 .03- .06 
 
 .04 
 
 1,157 
 
 (table 19) with Cd, Cu, Mg, Mo, Ni, Sr, V, and Zn, and is 
 negatively correlated with Al, Fe, K, Na, Si, and Ti. In the 
 MPS area, manganese shows a positive correlation with Co, 
 Mo, Ni, Pb, Sr, Zn, and Zr, and a negative correlation with Al 
 and Ca. In the other abyssal plains area, manganese is 
 positively correlated with Cd, Cu, Mo, Ni, and Zn, and 
 negatively correlated with Al, Fe, K, and Si. In the other 
 seamounts area, manganese is positively correlated with Ba, 
 Na, and Ni, and negatively correlated with Al, Cd, and Fe. 
 Where elements are not mentioned, no correlation (<0.3 to 
 >-0.3) was obtained. A positive correlation of manganese 
 with Cu, Ni, Mo, and Zn and a negative correlation of 
 manganese with Al and Fe are observed in all areas. The 
 difference in elemental composition between the lesser 
 depths (MPS and other seamounts) and greater depths (CC 
 Zone and other abyssal plains) may reflect differences in 
 oxidation potential as well as sediment type. 
 
 Iron 
 
 Iron concentrations in Pacific nodules vary from 1 to 25 
 wt-pct, with a median range of 6 to 1 7 wt-pct and a weighted 
 mean of 10.4 wt-pct based on 5,037 sample analyses. The 
 median value for CC-Zone area nodules is lowest of all areas 
 at 6 to 7 wt-pct with a mean of 6.9 wt-pct. The other three 
 areas are much higher in iron with a median range for these 
 areas of 12 to 17 wt-pct. Figure 15 provides histograms that 
 show iron distribution in each of the four areas. Iron occurs in 
 Pacific nodules as goethite and other iron oxides and 
 hydrated oxides as discussed in the "Mineralogy" section. 
 
 Iron in CC-Zone nodules is positively correlated (table 19) 
 with Co, Pb, Ti, and Zr, and negatively correlated with Cd, 
 Cu, Mg, Mn, Mo, Ni, and Zn. In the MPS area, iron is 
 positively correlated with Ti and Zr, and negatively correlated 
 with Ba and Ca. In the other abyssal plains area, iron is 
 positively correlated with Co, Pb, Sr, Ti, V, and Zr, and 
 negatively correlated with Cd, Cu, K, Mn, and Ni. In the other 
 seamounts area, iron is positively correlated with Cr, Ti, V, 
 and Zr, and negatively correlated with Ba, Ca, and Mn. 
 
 Nickel 
 
 Nickel concentrations in Pacific nodules vary from 0.1 to 
 2.0 wt-pct, with a median range of 0.3 to 1 .4 wt-pct and a 
 weighted mean of 0.9 wt-pct based on 5,074 sample 
 analyses. The median value for CC-Zone area nodules is 1 .3 
 to 1 .4 wt-pct with a mean of 1 .3 wt-pct. The other three areas 
 are much lower in nickel content with a median range of 0.3 
 to 0.6 wt-pct. Figure 16 provides histograms that show nickel 
 distributions for each of the four areas. 
 
 Nickel occurs in Pacific nodules as part of the manganese 
 mineral structure probably adding stability to the minerals. 
 The nickel is strongly correlated with manganese in all areas 
 of the Pacific. The ionic radius of Ni^* allows for direct 
 substitution of Ni^* for Mn^* in the crystal structures. 
 
 Nickel in CC-Zone area nodules is positively correlated 
 (table 19) with Cd, Cu, Mg, Mn, Mo, Sr, V, and Zn, and 
 negatively correlated with Fe, Si, and Ti. In the MPS area, 
 nickel is positively correlated with Co, Cr, Mg, Mn, Mo, Na, 
 and Zn, and negatively correlated with Al only. In the other 
 abyssal plains area, nickel is positively correlated with Cd, 
 Cu, Mn, Mo, and Zn, and negatively correlated with Fe and 
 Si. In the other seamounts area, nickel is positively correlated 
 with Cd, Co, Cu, Mg, Mn, and Zn, and no negative 
 correlations are found. 
 
 Copper 
 
 Copper concentrations in Pacific nodules vary from <0.01 
 to 2.0 wt-pct with a median range of <0.05 to 1 .1 wt-pct and a 
 weighted mean of 0.66 wt-pct based on 4,998 sample 
 analyses. The median value for CC-Zone area nodules is 1 .0 
 to 1 .1 wt-pct with a mean of 1 .0 wt-pct. The other three areas 
 are much lower in copper with a median range of <0.05 to 
 0.4 wt-pct. Figure 17 provides histograms that show copper 
 distribution in each of the four areas. 
 
19 
 
 270 
 
 243 
 
 216 
 
 189 
 
 162 
 
 135 
 
 108 
 
 27 
 
 Tf K^ 
 
 12 
 
 18 24 30 
 
 Mn-CC ZONE, pet 
 
 42 
 
 ID - 
 
 I 1 I- 
 
 1 1 1 ■ 
 
 14 - 
 
 
 r 
 
 12 ' 
 
 
 -| 
 
 10 - 
 
 
 -1 
 
 8 - 
 6 - 
 
 r 
 
 r-i 
 
 4 - 
 2 - 
 
 rn n r ttt 
 
 - -| p 
 
 PI 
 
 6 12 18 24 30 36 42 
 
 Mn-MID-PACIFIC SEAMOUNTS, pel 
 
 210 
 
 189 
 
 168 
 
 147 
 
 £ 126 - 
 
 105 
 
 = 84 
 O 
 
 63 
 
 42 
 
 24 
 
 ^rm r^ 
 
 o 
 
 !?i 15 
 
 O 
 
 o 
 o 
 
 LL 12 
 
 3 - 
 
 36 42 
 
 6 12 18 24 30 36 42 6 12 18 24 30 
 
 Mn-OTHER ABYSSAL, pel Mn-OTHER SEAMOUNTS, pel 
 
 Figure 14. — Manganese frequency distribution by environment for Pacific manganese nodules. 
 
20 
 
 520 
 
 468 
 
 416 
 
 364 
 
 260 
 
 208 
 
 156 
 
 104 
 
 52 
 
 -I 1 1 r 
 
 ttu 
 
 8 12 16 20 24 
 
 Fe-CC ZONE, pet 
 
 28 
 
 27 
 
 24 
 
 18 
 
 7? 15 
 
 12 
 
 u. 9 
 
 1 1 1 1 1 1 1 1 
 
 III' 
 
 8 12 18 20 
 
 Fe-MID-PACIFIC SEAMOUNTS, pet 
 
 24 28 
 
 230 
 
 27 
 
 24 - 
 
 21 - 
 
 8 '' 
 
 12 - 
 
 a 
 
 I 9 
 
 
 6 - 
 
 3 - —I - 
 
 207 
 
 184 
 
 161 
 
 U 
 
 ui 138 
 
 115 
 
 uj 92 
 
 46 - ^ 
 
 23 
 
 4 8 12 16 20 24 28 4 8 12 16 20 24 28 
 
 Fe-OTHER SEAMOUNTS, pet Fe-OTHER ABYSSAL, pet 
 
 Figure 1 5. — Iron frequency distribution by environment for Pacific manganese nodules. 
 
21 
 
 32S 
 
 246 
 
 123 
 
 0.6 0.9 1.2 1.5 
 
 Ni-CC ZONE, pel 
 
 15 ^ 
 
 n n 
 
 0.6 0.9 1.2 1.5 
 
 Ni-MID-PACIFIC SEAMOUNTS. pel 
 
 310 
 
 248 
 
 217 
 
 62 
 
 
 
 
 
 
 
 
 
 
 
 1 1 1 1 
 
 56 
 
 
 
 
 
 - 
 
 49 
 
 - 
 
 
 
 
 - 
 
 42 
 
 - 
 
 
 
 
 - 
 
 35 
 
 - 
 
 
 
 
 - 
 
 28 
 
 - 
 
 
 
 
 
 
 - 
 
 21 
 
 - 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 14 
 
 - 
 
 
 
 
 
 
 
 - 
 
 7 
 
 
 
 
 
 _ 
 
 
 
 - 
 
 
 -n 
 
 1 — 1 
 
 0.3 
 
 1.8 
 
 0.6 0.9 1.2 1.5 1.8 2.1 0.3 0.6 0.9 1.2 1.5 
 
 Ni-OTHER ABYSSAL, pet Ni-OTHER SEAMOUNTS, pel 
 
 Figure 16. — Nickel frequency distribution by environment for Pacific manganese nodules. 
 
 2.1 
 
22 
 
 350 
 
 315 
 
 280 
 
 245 
 
 = 210 
 O 
 
 o 
 o 
 
 140 
 
 105 
 
 70 
 
 35 - 
 
 -) 1 1 r r- 
 
 0.3 0.6 0.9 1.2 1.5 
 
 Cu-CC ZONE, pel 
 
 1.8 2.1 
 
 480 
 
 432 
 
 384 
 
 336 
 
 288 
 
 240 
 
 ^ 192 
 O 
 
 144 
 
 96 
 
 48 
 
 J 
 
 108 
 
 n 
 
 96 
 
 4 
 
 60 I 
 
 y 48^ 
 
 24 
 
 12 
 
 190 
 
 171 
 
 152 
 
 133 
 
 S 114 
 
 o 
 o 
 o 
 
 u. 95 
 O 
 
 U 
 
 76 ^ 
 
 57 
 
 38 
 
 19 
 
 0.3 0.6 0.9 1.2 1.5 1.8 
 
 Cu-MID-PACIFIC SEAMOUNTS, pet 
 
 0.3 0.6 0.9 1.2 1.5 1.8 2.1 
 
 Cu-OTHER ABYSSAL, pel 
 
 2.1 
 
 0.3 0.6 0.9 1.2 1.5 1.8 2.1 
 
 Cu-OTHER SEAMOUNTS, pet 
 
 Figure 1 7. — Copper frequency distribution by environment for Pacific manganese nodules. 
 
23 
 
 Copper occurs in Pacific nodules in a manner similar to 
 that of nickel, which is part of the manganese mineral 
 structure with no copper minerals present. The ionic radius of 
 Cu^' allows direct substitution for Mn^- in the manganese 
 minerals crystal structures. 
 
 Copper in CC-Zone area nodules is positively correlated 
 (table 19) with Al, Cd, Mg, Mn, Mo, Ni, Sr, V, and Zn, and 
 negatively correlated with Fe, K, Na, Pb, Si, Ti, and Zr. In the 
 MPS area, copper is positively correlated with Cr only and 
 negatively correlated with Al and Zr. In the other abyssal 
 plains area, copper is positively correlated with Cd, Mn, Ni, 
 and Zn, and negatively correlated with Fe and Pb. In the 
 other seamounts area, copper is positively correlated with 
 Cd, Mg, Ni, V, and Zn, and shows no negative correlation 
 with the other elements. 
 
 Cobalt 
 
 Cobalt concentrations in Pacific nodules vary from <0.05 
 to 2.5 wt-pct, with a median range of 0.2 to 0.8 wt-pct and a 
 weighted mean of 0.26 wt-pct based on 4,619 sample 
 analyses. The median value for CC-Zone area nodules is 0.2 
 to 0.3 wt-pct with a mean of 0.24 wt-pct. Cobalt values are 
 lowest in the two deep-ocean areas (CC Zone and other 
 abyssal plains) and the other seamounts area with all three 
 having similar median ranges and means. The MPS area has 
 the highest cobalt values, with a median range of 0.7 to 0.8 
 wt-pct and a mean of 0.76 wt-pct. Figure 18 provides 
 histograms that show cobalt distribution in each of the four 
 areas. 
 
 Cobalt occurs in Pacific nodules in both the manganese 
 and iron phases. Its occurrence is dependent on the 
 oxidation of cobalt to either Co^^ or Co^". In the MPS area, 
 oxidation to Co^" is one probable explanation of high cobalt 
 values, whereas in the deep ocean the oxidation potential 
 may be insufficient to oxidize Co^' to Co^". Some cobalt in 
 nodules can also be attributed to volcanic seamounts. Cobalt 
 in the Co^' state has an ionic radius similar to Mn^-, whereas 
 Co'' has an ionic radius very close to that of Mn"' and 
 substitutes for Mn"' in vernadite (13, 100). 
 
 Cobalt in CC-Zone area nodules has a slight positive 
 correlation (table 19) with Fe, Pb, and Ti, and a slight 
 negative correlation with Cd. In the MPS area, cobalt is 
 positively correlated with Ba, Mg, Mn, Ni, Pb, Sr, Ti, and Zr. 
 and negatively correlated with Al, Ca, K, Na, and Si. In the 
 other abyssal plains area, cobalt has a slight positive 
 correlation with Fe and Sr, and a slight negative correlation 
 with Al, Cd, and Si. In the other seamounts area, cobalt is 
 positively correlated with Ti and Pb, and has a slight positive 
 correlation with Ni. Cobalt in this area has a slight negative 
 correlation with Cd and Si. 
 
 Zinc 
 
 Zinc concentrations in Pacific nodules vary from <0.05 to 
 0.95 wt-pct, with a median value of 0.05 to 0.15 wt-pct and a 
 weighted mean of 0.11 wt-pct based on 3,097 sample 
 analyses. The median value for CC-Zone area nodules is 
 0.10 to 0.15 wt-pct with a mean of 0.14 wt-pct. Zinc values 
 are highest in CC-Zone nodules; approximately a factor of 
 two higher than in the other three areas. The median range 
 for the other three areas is 0.05 to 0.10 wt-pct with a mean 
 range of 0.07 to 0.09 wt-pct; the lower values occur in the 
 seamount areas. Figure 19 provides histograms that show 
 zinc distribution in each of the four areas. 
 
 Zinc appears to occur in Pacific nodules as a substitute in 
 the manganese mineral structure similar to copper and 
 nickel. No zinc minerals have been identified in Pacific 
 nodules. The zinc ionic radius is similar to Mn^ and would 
 allow a direct substitution. 
 
 Zinc in CC-Zone area nodules is positively correlated 
 
 (table 19) with Cu, Mn, and Ni, and negatively correlated with 
 Fe and Zr, with only a slight negative correlation with Pb and 
 Ti. In the MPS area, zinc is positively correlated with Ba, Mn, 
 Na, Ni, and V, and negatively correlated with Mg, Ti, and Zr. 
 In the other abyssal plains area, zinc is positively correlated 
 with Cu, Mn, and Ni, and negatively correlated with Al. In the 
 other seamounts area, zinc is positively correlated with Cd, 
 Cu, and Ni, and negatively correlated with Na. 
 
 Vanadium 
 
 Vanadium concentrations in Pacific nodules vary from 
 <0.005 to 0.300 wt-pct, with a median value of 0.040 to 
 0.080 wt-pct and a weighted mean of 0.050 wt-pct based on 
 507 sample analyses. The median value for CC-Zone area 
 nodules is 0.04 to 0.05 wt-pct with a mean of 0.047 wt-pct. 
 The CC-Zone area and other abyssal plains area have 
 somewhat lower median and mean values than the two 
 seamount areas by about a factor of 1 .5 to 2.0. Figure 20 
 provides histograms that show vanadium distribution for 
 each of the four areas. 
 
 Vanadium appears to be another of the many elements 
 that occur with manganese and may possibly substitute for 
 Mn'* or fill the large tunnels in the manganese mineral 
 structure as oxides. Correlation coefficient data (table 19) 
 indicate a tendency for vanadium to occur with Mn, Cu, and 
 Ni, all of which have been shown to substitute for manganese 
 in the manganese mineral structure. 
 
 Vanadium in CC-Zone area nodules correlates with Ca, 
 Cu, Mn, and Ni, and negatively with Al and Na. In the MPS 
 area, vanadium correlates positively with K, Na, and Zn, and 
 negatively with Mo, Pb, and Ti. In the other abyssal plains 
 area, vanadium correlates positively with Fe and Mo and 
 negatively with Si. In the other seamounts area, vanadium 
 correlates positively with Al, Cu, Fe, K, and Ti, and negatively 
 with Ba and Ca. Vanadium data for the seamounts areas are 
 very limited; therefore, correlation coefficients may not 
 accurately reflect the actual correlation of vanadium to other 
 elements. 
 
 Molybdenum 
 
 Molybdenum concentrations in Pacific nodules vary from 
 <0.005 to 0.150 wt-pct, with a median value of 0.03 to 0.06 
 wt-pct and a weighted mean of 0.04 wt-pct based on 1,157 
 sample analyses. The median value for CC-Zone area 
 nodules is 0.05 to 0.06 wt-pct with a mean value of 0.05 
 wt-pct. Molybdenum concentrations appear to be somewhat 
 uniform throughout all four areas with only a slightly lower 
 mean for the other abyssal plains area. Figure 21 provides 
 histograms that show molybdenum distribution for each of 
 the four areas. 
 
 Moiyboenum appears to occur in a manner similar to that 
 of Cu and Ni; that is, as a substitute in the manganese 
 mineral structure. No molybdenum minerals have been 
 identified in Pacific nodules. The ionic radius of molybdenum 
 in oxidation states 4 and 6 is similar to Mn"*, and therefore it 
 may be a substitute for Mn" or it may be contained in the 
 smaller tunnel structure of the manganese minerals. 
 
 Molybdenum in CC-Zone area nodules is positively 
 correlated (table 19) with Cd, Cu, Mn, and Ni, and negatively 
 correlated with Fe. In the MPS area, molybdenum is 
 positively correlated with Mn, Na, and Ni, and negatively 
 correlated with Al and V. In the other abyssal plains area, 
 molybdenum is positively correlated with Cd, Mn, Ni, and V, 
 and negatively correlated with Al and Si. In the other 
 seamounts area, molybdenum is positively correlated with 
 Na and Pb and has no negative correlation. Molybdenum 
 data in the two seamounts areas are limited; therefore, 
 correlation coefficients may not accurately reflect the actual 
 correlation of molybdenum to other elements. 
 
24 
 
 936 
 
 - 
 
 
 1 1 1 
 
 832 
 
 - 
 
 
 - 
 
 UJ 728 
 
 
 
 
 O 
 
 
 
 
 fi 
 
 
 
 
 IT 
 
 
 
 
 IT 
 
 
 
 
 3 624 
 
 ^ 
 
 
 - 
 
 O 
 
 
 
 
 O 
 
 
 
 
 u. 
 
 
 
 
 O 
 
 
 
 
 
 > 520 
 
 ^ 
 
 
 
 - 
 
 o 
 
 
 
 
 
 y 
 
 
 
 
 
 
 
 
 
 
 3 
 
 
 
 
 
 o -.„ 
 
 
 
 
 
 g 416 
 11. 
 
 h 
 
 
 
 - 
 
 
 
 
 
 312 
 
 - 
 
 
 
 
 - 
 
 208 
 
 - 
 
 
 
 
 - 
 
 104 
 
 _ 
 
 
 
 
 
 1 1 1 
 
 0.3 
 
 0.6 0.9 
 
 Co-CC ZONE, pet 
 
 1.2 
 
 1.5 
 
 32 
 
 28 - 
 
 24 
 
 20 
 
 16 
 
 12 
 
 0.3 0.6 0.9 1.2 
 
 Co-MID-PACIFIC SEAMOUNTS, pet 
 
 1.5 
 
 567 
 
 - 
 
 
 1 1 1 1 
 
 504 
 
 - 
 
 
 
 T 
 
 441 
 
 - 
 
 
 
 - 
 
 OF OCCURRENCE 
 
 Cfl 00 
 
 ^- 
 
 
 
 
 - 
 
 FREQUENCY 
 
 
 
 
 
 
 - 
 
 
 
 
 
 189 
 
 
 
 
 
 
 
 126 
 
 - 
 
 
 
 
 
 - 
 
 63 
 
 - 
 
 
 
 
 
 
 Ik-,, — , . 
 
 72 
 
 63 
 
 54 
 
 45 
 
 36 
 
 27 
 
 18 
 
 ^ m 
 
 1.5 
 
 0.3 0.6 0.9 1.2 
 
 Co-OTHER ABYSSAL, pet 
 
 Figure 18 Cobalt frequency distribution by environment for Pacific manganese nodules. 
 
 0.3 0.6 0.9 1.2 
 
 Co-OTHER SEAMOUNTS, pet 
 
 1.5 
 
25 
 
 800 
 
 0.15 0.30 0.45 0.60 0.75 0.90 1.05 
 
 Zn-CC ZONE, pet 
 
 0.15 0.30 0.45 0.60 0.75 0.90 1.05 
 
 Zn-MID-PACIFIC SEAMOUNTS, pet 
 
 fbu 
 
 1 — 1 
 
 — 1 1 r- 1 1 1 
 
 684 
 
 
 
 " 
 
 608 
 
 - 
 
 
 - 
 
 532 
 
 _ 
 
 
 - 
 
 OCCURRENCE 
 
 - 
 
 
 -. 
 
 fe 380 
 
 - 
 
 
 - 
 
 FREQUENCY 
 
 - 
 
 
 - 
 
 228 
 
 - 
 
 
 
 - 
 
 152 
 
 - 
 
 
 
 - 
 
 76 
 
 - 
 
 
 
 
 — 1 
 
 108 
 
 - 
 
 — 1 
 
 1 1 1 1 ' 1 
 
 96 
 
 - 
 
 
 - 
 
 84 
 
 - 
 
 
 - 
 
 72 
 
 - 
 
 
 - 
 
 60 
 
 - 
 
 
 - 
 
 48 
 
 ^ 
 
 
 - 
 
 36 
 
 - 
 
 
 - 
 
 24 
 
 - 
 
 
 - 
 
 12 
 
 - 
 
 
 
 n ^ , ^ , , , 
 
 0.15 0.30 0.45 0.60 0.75 0.90 1.05 0.15 0.30 0.45 0.60 0.75 0.90 1.05 
 
 Zn-OTHER ABYSSAL, pel Zn-OTHER SEAMOUNTS, pel 
 
 Figure 19. — Zinc frequency distribution by environment for Pacific manganese nodules. 
 
26 
 
 500 1,000 1,500 2,000 2,500 
 
 V-CC ZONE, ppm 
 
 500 1,000 1,500 2,000 2,500 
 
 V-MID-PACIFIC SEAMOUNTS, ppm 
 
 90 
 
 81 - 
 
 72 - 
 
 63 
 
 54 
 
 O 
 O 
 O 
 
 u. 45 
 O 
 
 >- 
 U 
 
 I 36 
 
 27 
 
 18 
 
 \h 
 
 n-n 
 
 500 
 
 1,000 1,500 2,000 2,500 
 
 O 
 O 
 O 
 u. 4 
 
 1 I I 
 
 1 - - 
 
 500 
 
 1,000 
 
 1,500 2,000 2,500 
 
 V-OTHER ABYSSAL, ppm V-OTHER SEAMOUNTS, ppm 
 
 Figure 20. — Vanadium frequency distribution by environment for Pacific manganese nodules. 
 
27 
 
 
 54 
 
 1 
 
 
 1 1 
 
 
 48 
 
 - 
 
 
 
 ~ 
 
 
 42 
 
 - 
 
 
 
 
 
 
 _ 
 
 UJ 
 
 
 
 o 
 
 
 
 
 
 
 
 
 
 z 
 
 
 
 
 
 
 
 
 
 UJ 
 
 cr 
 
 36 
 
 - 
 
 
 
 
 
 
 - 
 
 a 
 
 
 
 
 
 
 
 
 
 3 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 U 
 
 
 
 
 
 
 
 
 
 o 
 
 
 
 
 
 
 
 
 
 u. 
 
 M 
 
 - 
 
 
 
 
 
 
 - 
 
 o 
 
 
 
 
 
 
 
 
 
 >- 
 
 
 
 
 
 
 
 
 
 o 
 
 
 
 
 
 
 
 
 
 z 
 
 
 
 
 
 
 
 
 
 UJ 
 
 24 
 
 ^ 
 
 
 
 
 
 
 - 
 
 o 
 
 
 
 
 
 
 
 
 
 m 
 
 
 
 
 
 
 
 
 
 IT 
 
 
 
 
 
 
 
 
 
 Ll 
 
 18 
 
 „ 
 
 
 
 
 
 
 - 
 
 
 12 
 
 ^ 
 
 
 
 
 
 
 
 - 
 
 
 6 
 
 - 
 
 
 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 1 
 
 0.03 0.06 0.09 0.12 
 
 Mo-CC ZONE, pet 
 
 0.15 
 
 14 
 
 12 
 
 10 
 
 2 - 
 
 _L_ 
 
 0.03 0.06 0.09 0.12 0.15 
 
 Mo-MID-PACIFIC SEAMOUNTS, pet 
 
 
 180 
 
 - 
 
 
 1 1 1 
 
 
 160 
 
 - 
 
 
 
 - 
 
 
 140 
 
 - 
 
 
 
 _ 
 
 m 
 o 
 
 z 
 
 Ul 
 IT 
 CC 
 
 =) 
 
 o 
 o 
 o 
 
 u. 
 O 
 
 120 
 100 
 
 - 
 
 
 
 
 - 
 
 " 
 
 
 1 
 
 - 
 
 > 
 
 o 
 
 z 
 
 UJ 
 
 8 
 
 UJ 
 
 rr 
 
 80 
 
 
 
 
 
 
 
 - 
 
 u. 
 
 
 
 
 60 
 
 
 
 
 
 
 
 - 
 
 
 40 
 
 - 
 
 
 
 
 
 
 
 - 
 
 
 20 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 1 1 
 
 
 1 1 1 1 
 
 0.03 
 
 0.06 
 
 0.09 
 
 0.12 
 
 0.15 
 
 12 
 
 - 
 
 
 
 
 
 1 1 1 
 
 10 
 
 
 
 
 
 
 
 - 
 
 8 
 
 
 
 
 
 
 
 
 - 
 
 6 
 
 - 
 
 
 
 
 
 
 
 - 
 
 4 
 
 - 
 
 
 
 
 
 
 
 
 - 
 
 2 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 - 
 
 0.03 
 
 0.06 
 
 0.09 
 
 0.12 
 
 0.15 
 
 Mo-OTHER ABYSSAL, pet Mo-OTHER SEAMOUNTS, pet 
 
 Figure 21 — Molybdenum frequency distribution by environment tor Pacific manganese nodules. 
 
28 
 
 Table 7. — Distribution of other major and minor elements in Pacific manganese nodules, by area, 
 
 weight-percent 
 
 Standard 
 Area Range Median Mean, deviation Number of 
 
 X of mean, samples 
 ax 
 
 Standard 
 Range Median Mean, deviation Number of 
 X of mean, samples 
 
 crx 
 
 Aluminum 
 
 Sodium 
 
 Clarion-Clipperton zone. 0.50-8 00 2.50-3.00 2.90 1.04 234 
 Mid-Pacific seamounts. . <. 25- 6.00 .25- .75 1.20 .94 48 
 Other abyssal plains, 
 
 >3,000 m <.50-10.0 2.50-3.00 3.05 1.48 570 
 
 Other seamounts, 
 
 0,000 m <. 50- 7.00 1.00-1.50 1.70 1.11 79 
 
 0.50 -6.75 2.00-2.25 2.79 1.72 106 
 .50 -5.50 1.45-1.55 2.13 1.04 28 
 
 <.25 -5.75 1.75-2.00 2.07 .78 297 
 
 .25 -3.75 1.25-1.50 1.64 .76 37 
 
 Calcium 
 
 Strontium 
 
 Clarion-Clipperton zone. <0.5 -18.0 1.5-2.0 1.7 0.8 872 
 Mid-Pacific seamounts. . <.5 -25.0 2.0 - 2.5 4.2 3.9 91 
 Other abyssal plains, 
 
 >3,000 m <.5 -13.0 1.5-2.0 1.8 1.2 914 
 
 Other seamounts, 
 
 0,000 m <.5 -25.0 2.0-3.0 4.5 5.3 200 
 
 <0.005-0.16 0.04-0.05 0.045 0.03 78 
 <.005- .30 .14- .15 .13 .07 27 
 
 <.005- .18 .07- .08 .08 .03 320 
 
 <.005- .28 .13- .14 .135 .06 68 
 
 Magnesium 
 
 Titanium 
 
 Clarion-Clipperton zone. <0. 25- 3.00 1.50-1.75 1.65 0.43 209 
 Mid-Pacific seamounts. . .50-3.50 .75-1.25 1.41 .52 35 
 Other abyssal plains, 
 
 >3,000 m <. 25- 5.00 1.25-1.50 1.43 .69 361 
 
 Other seamounts, 
 
 <3,000 m <. 25- 4.25 1.50-1.75 1.79 .84 64 
 
 0.10 -2.20 0.40-0.50 0.53 0.29 265 
 .20 -2.20 1.10-1.20 1.12 .40 102 
 
 <.05 -2.50 .60- .70 .78 .75 854 
 
 <.05 -1.60 .40- .50 .47 .35 89 
 
 Potassium 
 
 Zirconium 
 
 Clarion-Clipperton zone 0.20-3.00 0.80-0.90 1.01 0.53 123 
 Mid-Pacific seamounts. . .10- .90 .30- .40 .41 16 35 
 Other abyssal plains, 
 
 >3,000 m 10- 3.00 .70- .80 .93 .60 335 
 
 Other seamounts, 
 
 0,000 m .10-1.60 .30- .40 .54 .47 66 
 
 0.010-0.09 0.03-0.04 0.035 0.01 33 
 <.005- .11 .07- .075 .06 .03 18 
 
 <.005- .20 .05- .06 .06 .04 226 
 
 <.005- .20 .04- .05 .05 .04 27 
 
 Silicon 
 
 
 Clarion-Clipperton zone. 1.0-25.0 6.0-6.5 7.6 2.91 339 
 Mid-Pacific seamounts. . <. 50-15.0 2.0-3.0 3.6 3.03 45 
 Other abyssal plains, 
 
 >3,000 m <. 50-25.0 7.0 - 8.0 8.8 5.10 460 
 
 Other seamounts, 
 
 0,000 m <. 50-23.0 3.0 - 4.0 4.8 4.45 91 
 
 
 General Observations 
 
 CC-Zone area nodules contain the highest levels of Mn, Ni, 
 Cu, and Zn and the lowest amounts of Fe and Co. Vanadium 
 is slightly lower in the CC-Zone area than in other areas and 
 molybdenum appears to be uniformly concentrated in all 
 areas. The seamounts areas contain the highest levels of Fe 
 and Co with a slight elevation of V, and they contain the 
 lowest levels of Ni and Cu. The different environments 
 encountered in the seamounts areas versus the abyssal 
 areas may show the effect of oxidation and sediment types 
 on the formation of Pacific nodules. Cobalt occurs with both 
 the Fe and Mn phases, with higher Co and Fe values being 
 observed in nodules formed in the more elevated sea floor 
 areas (MPS and other seamounts areas). The majority of 
 data in this section came from the work of Frazer {44, 48-50), 
 Sorem {118), and Fewkes {42-43). 
 
 Table 8. — Distribution of other major and minor 
 elements in Pacific manganese nodules, compo- 
 site, weight-percent 
 
 Element Range 
 
 Aluminum <0.25 -10.0 
 
 Calcium < .05 -25.0 
 
 Magnesium < .25 - 5.0 
 
 Potassium .10-3.0 
 
 Silicon <.50 -25.0 
 
 Sodium <.25 - 6.75 
 
 Strontium <.005- .300 
 
 Titanium <.05 - 2.50 
 
 Zirconium <.005- .20 
 
 Range of 
 medians' 
 
 Weighted 
 mean 
 
 Number of 
 samples 
 
 0.25-3.0 
 
 2.80 
 
 931 
 
 1 .50-3.0 
 
 2.12 
 
 2,077 
 
 .75-1.75 
 
 1.53 
 
 669 
 
 .30- .90 
 
 .87 
 
 559 
 
 2.0 -8.0 
 
 7.72 
 
 935 
 
 1.25-2.25 
 
 2.20 
 
 468 
 
 .04- .15 
 
 .083 
 
 493 
 
 .40-1.20 
 
 .73 
 
 1,310 
 
 .03- .075 
 
 .058 
 
 304 
 
 OTHER MAJOR AND 
 MINOR ELEMENTS 
 
 The major and minor elements discussed in this section 
 are not of any present economic or environmental interest as 
 applied to manganese nodule processing. The nine ele- 
 ments, Al, Ca, Mg, K, Si, Na, Sr, Ti, and Zr, are presented in 
 the same manner as those of economic interest, with data 
 divided into the four geographic areas as shown in table 7. 
 Possible mineral forms and compounds are presented as 
 well as positive and negative interelement correlations (table 
 19). Table 8 gives composite data for these elements from 
 Pacific nodules. 
 
 Aluminum 
 
 Aluminum concentrations in Pacific nodules vary from 
 <0.25 to 10.0 wrt-pct, with a median value of 0.25 to 3.00 
 wt-pct and a weighted mean of 2.80 wt-pct based on 931 
 sample analyses. The median value for CC-Zone area 
 nodules is 2.5 to 3.0 wt-pct with a mean of 2.9 wt-pct. 
 Nodules from the two abyssal plains areas contain about 
 twice the amount of aluminum found in nodules from the two 
 seamounts areas. The two seamount areas have a median 
 range of 0.25 to 1 .5 wt-pct, with means around 1 .2 wt-pct for 
 MPS area and 1.7 wt-pct for the other seamounts area. 
 Figure 22 provides histograms that show aluminum distribu- 
 tion in each of the four areas. 
 
29 
 
 14U 
 
 
 
 
 
 
 
 
 [-- 1 -1 
 
 126 
 
 
 
 - 
 
 112 
 
 - 
 
 
 - 
 
 98 
 
 - 
 
 
 - 
 
 84 
 
 - 
 
 
 - 
 
 70 
 
 - 
 
 
 - 
 
 56 
 
 - 
 
 
 - 
 
 42 
 
 - 
 
 
 
 - 
 
 28 
 
 - 
 
 
 
 
 - 
 
 14 
 
 - 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 4 6 8 
 
 AI-CC ZONE, pet 
 
 10 
 
 12 
 
 27 
 
 24 
 
 18 
 
 15 
 
 12 
 
 a. Q 
 
 3 - 
 
 r\. 
 
 2 4 6 8 10 
 
 AI-MID-PACIFIC SEAMOUNTS, pet 
 
 12 
 
 C\>\i 
 
 1 1 1 1 1 
 
 180 
 
 - 
 
 
 - 
 
 160 
 
 - 
 
 
 - 
 
 140 
 
 - 
 
 
 
 - 
 
 CCURRENCE 
 
 ro 
 
 o 
 
 - 
 
 
 
 
 _ 
 
 o 
 
 u. 100 
 
 O 
 
 r 
 
 
 FREQUENCY 
 
 00 
 
 o 
 
 - 
 
 
 
 
 - 
 
 60 
 
 - 
 
 
 
 
 - 
 
 40 
 
 
 
 
 
 
 - 
 
 20 
 
 
 
 
 
 
 
 
 
 ■■I 1 
 
 12 
 
 JU 
 
 27 
 
 - 
 
 T T 
 
 1 1 1 
 
 24 
 
 - 
 
 ! 1 
 
 - 
 
 21 
 
 - 
 
 
 
 
 - 
 
 18 
 
 - 
 
 
 
 
 - 
 
 15 
 
 - 
 
 
 
 
 - 
 
 12 
 
 - 
 
 
 
 
 - 
 
 9 
 
 
 
 
 
 - 
 
 6 
 
 - 
 
 
 
 
 - 
 
 3 
 
 
 
 
 
 1 
 
 1 1 , 
 
 10 
 
 12 
 
 AI-OTHER ABYSSAL, pet AI-OTHER SEAMOUNTS, pet 
 
 Figure 22 — Aluminum frequency distribution by environment for Pacific manganese nodules. 
 
30 
 
 Aluminum occurs primarily as an aluminum silicate in clay 
 inclusions in Pacific nodules in the form of alkali and 
 plagioclase feldspars. This is reflected in the correlation data 
 (table 19) by positively correlating with K, Si, and, in some 
 cases, Na. No correlation with Ca is observed except for a 
 slight negative correlation in the other seamounts area. The 
 most likely form is plagioclase, other feldspars, and clays. 
 
 Aluminum in CC-Zone area nodules correlates positively 
 with Ba, Cu, K, Na, and Si and negatively with Cd, Mg, Mn, 
 Sr, and V. In the MPS area, aluminum is positively correlated 
 with Cr, Mg, Ti, and Zr, and negatively correlated with Co, 
 Cu, Mn, Mo, Na, and Ni. In the other abyssal plains area, 
 aluminum is positively correlated with K and Si, and 
 negatively correlated with Cd, Co, Mn, Mo, and Zn. In the 
 other seamounts area, aluminum is positively correlated with 
 Si, V, and Zr, and a slight negative correlation is observed 
 with Ca, Cr, Mn, and Sr. 
 
 Calcium 
 
 Calcium concentrations in Pacific nodules vary from <0.5 
 to 25.0 wt-pct, with a median value of 1 .5 to 3.0 wt-pct and a 
 weighted mean of 2.1 wt-pct based on 2,077 sample 
 analyses. The median value for CC-Zone area nodules is 1 .5 
 to 2.0 wt-pct with a mean of 1 .7 wt-pct. Nodules from the two 
 abyssal plains areas contain about one-half the calcium 
 levels of nodules from the two seamounts areas. These two 
 areas have a median range of 2.0 to 3.0 wt-pct with means 
 between 4.2 and 4.5 wt-pct. Figure 23 provides histograms 
 that show calcium distribution in each of the four areas. 
 
 Calcium occurs in Pacific nodules in several possible 
 forms. It can occur in some cases as calcite, apatite and/or in 
 feldspars, and it correlates negatively in some areas with Fe 
 and Mn. Calcium also is known to substitute in the 
 manganese mineral structure to some degree. The multiform 
 occurrence may be why the correlation coefficients (table 19) 
 are not conclusive evidence for calcium association. 
 
 Calcium in CC-Zone area nodules correlates positively 
 with Cd, Sr, and V, and negatively with Ba. In the MPS area, 
 calcium correlates positively with Sr and negatively with Cr, 
 Co, Fe, and Mn. In the other abyssal plains area, calcium 
 correlates positively with Mg and has no negative correlation. 
 In the other seamounts area, calcium correlates positively 
 with Cd and Sr, and negatively with Al, Fe, K, Na, Si, Ti, and 
 V. 
 
 Magnesium 
 
 Magnesium concentrations in Pacific nodules vary from 
 <0.25 to 5.0 wt-pct, with a median value of 0.75 to 1.75 
 wt-pct and a weighted mean of 1.53 wt-pct based on 669 
 sample analyses. The median value for CC-Zone area 
 nodules is 1.5 to 1.75 wt-pct with a mean of 1.65 wt-pct. 
 Magnesium concentrations are uniform in all four areas with 
 only insignificant differences in median ranges and means. 
 Figure 24 provides histograms that show magnesium 
 distribution in each of the four areas. 
 
 Magnesium occurs in Pacific nodules in several forms. 
 Some of the magnesium content of nodules is a result of 
 dissolved seawater salts. Magnesium also appears to occur 
 in the manganese mineral structure based on its positive 
 correlation (table 19) with Mn, Ni, and Cu in most areas. Its 
 ionic radius is such that it could substitute in the same sites 
 as Cu and Ni in the manganese crystal structure. 
 
 Magnesium in CC-Zone area nodules correlates positively 
 with Cu, Mn, Ni, and Sr, and negatively with Al, Fe, K, Na, 
 and Ti. In the MPS area, magnesium is positively correlated 
 with Al, Co, Cr, Ni, Pb, and Sr, and negatively correlated with 
 Zn and Zr, In the other abyssal plains area, magnesium is 
 positively correlated with Cd and Ca (slightly) and shows no 
 negative correlation. In the other seamounts area, magne- 
 sium is positively correlated with Ba, Cu, and Ni, and 
 negatively correlated with Na and Sr. 
 
 Potassium 
 
 Potassium concentrations in Pacific nodules vary from 
 0.10 to 3.0 wt-pct, with a median value of 0.30 to 0.90 wt-pct 
 and a weighted mean of 0.87 wt-pct based on 559 sample 
 analyses. The median value for CC-Zone area nodules is 
 0.80 to 0.90 wt-pct with a mean of 1.01 wt-pct. The two 
 abyssal plains areas contain about two times the amount of 
 potassium found in the two seamounts areas. The median 
 value for the seamounts areas is 0.30 to 0.40 wt-pct with 
 means of 0.41 and 0.54 wt-pct. Figure 25 provides 
 histograms that show potassium distribution in each of the 
 four areas. 
 
 The occurrence of potassium in Pacific nodules is in two 
 forms: as dissolved sea salts that crystallize when the 
 samples dry, probably as KCI (sylvite), and as plagioclase 
 feldspars. Evidence for the latter is seen in the high 
 correlation coefficients (table 19) for potassium with Al, Si, 
 and Na. 
 
 Potassium in CC-Zone area nodules is positively corre- 
 lated with Al, Na, and Si, and negatively correlated with Cu, 
 Mg, Mn, and Sr. In the MPS area, potassium is positively 
 correlated with Na, Si, and V, and negatively correlated with 
 Co and Pb. In the other abyssal plains area, potassium is 
 positively correlated with Al and Si and negatively correlated 
 with Cd, Fe, Mn, and Sr. In the other seamounts area, 
 potassium is positively correlated with Cr and V and 
 negatively correlated with Ca and Sr. 
 
 Silicon 
 
 Silicon concentrations in Pacific nodules vary from <0.50 
 to 25 wt-pct, with a median value of 2.0 to 8.0 wt-pct and a 
 weighted mean of 7.7 wt-pct based on 935 sample analyses. 
 The median value for CC-Zone area nodules is 6.0 to 6.5 
 wt-pct with a mean of 7.6 wt-pct. Silicon content in the two 
 abyssal plains areas is a factor of two higher than for the two 
 seamounts areas. The two seamounts areas have a median 
 range of 2.0 to 4.0 wt-pct, with mean values of 3.6 wt-pct for 
 the MPS area and 4.8 wt-pct for the other seamounts area. 
 Figure 26 provides histograms that show silicon distribution 
 in each of the four areas. 
 
 Silicon occurs in Pacific nodules in two forms. It occurs as 
 silicates in the feldspars and clays and as silica (Si02). 
 Silicon in CC-Zone area nodules correlates positively (table 
 19) with Al, K, and Na, and negatively with Cu, Mn, Ni, and 
 Sr. In the MPS area, silicon correlates positively with Cr, K, 
 Na, and Zr, and negatively with Co, Pb, and Sr. In the other 
 abyssal plains area, silicon correlates positively with Al, Cr, 
 and K, and negatively with Co, Mn, Mo, Ni, Sr, V, and Zr. In 
 the other seamounts area, silicon is correlated positively with 
 Al and negatively with Ba, Ca, Co, and Sr. 
 
 Sodium 
 
 Sodium concentrations in Pacific nodules vary from <0.25 
 to 6.75 wt-pct, with a median value of 1 .25 to 2.25 wt-pct and 
 a weighted mean of 2.20 wt-pct based on 468 sample 
 analyses. The median value for CC-Zone area nodules is 2.0 
 to 2.25 wt-pct with a mean value of 2.8 wt-pct. Sodium 
 content of Pacific nodules from all four areas is similar with 
 lower sodium values occurring in the two seamounts areas 
 based on limited data in these areas. Figure 27 provides 
 histograms that show sodium distribution in each of the four 
 areas. 
 
 Sodium occurs in Pacific nodules in several forms. It 
 occurs as dissolved sea salts that crystallize upon drying. It 
 can also occur in some feldspars in the plagioclase group. 
 Sodium is also a constituent of the manganese mineral 
 structure of todorokite but is generally replaced by other 
 cations such as Cu^' and Ni^*, which are thought to stabilize 
 the crystal structure of the todorokite. 
 
 Sodium in CC-Zone area nodules is correlated positively 
 
31 
 
 12 16 20 
 
 Ca-CC ZONE, pet 
 
 8 12 16 20 
 
 Ca-MID-PACIFIC SEAMOUNTS, pet 
 
 O 
 
 u. 35 
 
 O 
 
 21 h 
 
 MlTff^ n 
 
 .^d^ 
 
 8 12 16 20 
 
 Ca-OTHER ABYSSAL, pet 
 
 8 12 16 20 
 
 Ca-OTHER SEAMOUNTS, pet 
 
 Figure 23. — Calcium frequency distribution by environment for Pacific manganese nodules. 
 
 (table 19) with Al, Ba, K, Si, and Ti, and negatively with Cd, 
 Cu, Mg, Mn, Sr, and V. In the MPS area, sodium is correlated 
 positively with Ba, K, Mo, Ni, Si, V, and Zn, and negatively 
 with Al, Co, Cr, Pb, Sr, and Ti. In the other abyssal plains 
 area, sodium is correlated positively with none of the other 
 elements and negatively with Cd and Cr. In the other 
 seamounts area, sodium is correlated positively with Mn and 
 Mo and negatively with Ca, Cr, Mg, and Zn. 
 
 Strontium 
 
 Strontium concentrations in Pacific nodules vary from 
 <0.005 to 0.300 wt-pct, with a median value of 0.04 to 0.15 
 
 wt-pct and a weighted mean value of 0.083 wt-pct based on 
 493 sample analyses. The median value for CC-Zone area 
 nodules is 0.04 to 0.05 wt-pct with a mean value of 0.045 
 wt-pct. Strontium values are lower by a factor of two to three 
 in the two abyssal plains areas than in the two seamounts 
 areas. The two seamounts areas have a median range of 
 0.13 to 0.15 wt-pct with a mean of 0.135 wt-pct. Figure 28 
 provides histograms that show strontium distribution in each 
 of the four areas. 
 
 Strontium substitutes for calcium in the manganese 
 nodules. Strontium is positively correlated (table 19) with Ca 
 and in some areas with Mn, Ni, and Cu. Calcium can be part 
 of the manganese mineral structure and is replaced bv 
 
32 
 
 63 
 
 56 
 
 49 
 
 42 
 
 35 
 
 28 
 
 £ 21 
 
 90 
 
 72 - 
 
 63 
 
 UJ 
 
 S 54 
 
 45 
 
 36 
 
 27 - 
 
 18 - 
 
 ~1 — I 
 
 2 3 
 
 Mg-CC ZONE, pet 
 
 l>n ^ , r^ 
 
 12 3 4 
 
 Mg-MID-PACIFIC SEAMOUNTS, pet 
 
 
 1 
 
 
 
 1 1 1 
 
 14 
 
 
 
 10 
 
 - 
 
 - 
 
 8 
 6 
 
 — 
 
 |— 1 
 
 4 
 2 
 
 — 1 p 
 
 —1 
 
 012345 01234 
 
 Mg-OTHER ABYSSAL, pet Mg-OTHER SEAMOUNTS, pet 
 
 Figure 24. — Magnesium frequency distribution by environment for Pacific manganese nodules. 
 
33 
 
 18 - 
 
 15 
 
 OliJ^Il 
 
 54 I — 
 
 42 
 
 36 
 
 24 
 
 IB - 
 
 ifDizfikif 
 
 0.5 1.0 1.5 2.0 2.5 
 
 K-MID-PACIFIC SEAMOUNTS, pet 
 
 3.0 
 
 18 
 
 15 
 
 12 
 
 9 
 
 6 
 
 3 
 
 - 
 
 ^ 
 
 
 
 -1 
 
 
 r-i 
 
 
 
 
 
 
 
 1 I 1 — 
 
 
 
 
 
 
 
 1 1 
 
 0.5 
 
 2.5 
 
 3.0 
 
 0.5 
 
 1.0 
 
 1.5 
 
 2.0 
 
 2.5 
 
 1.0 1.5 2.0 
 
 K-OTHER ABYSSAL, pet. K-OTHER SEAt\/10UNTS, pet. 
 
 Figure 25. — Potassium frequency distribution by environment for Pacific manganese nodules. 
 
34 
 
 H 50 
 
 10 r r-i ' 
 
 rmK. 
 
 n 
 
 12 16 20 
 
 Si-CC ZONE, pet 
 
 28 
 
 32 - 
 
 24 - 
 
 
 1 ! 1 1 
 —1 
 
 1 h^ 
 
 8 12 16 20 
 
 Si-MID-PACIFIC SEAMOUNTS, pet 
 
 28 
 
 24 
 
 
 
 1 1 1 I 1 1 1 
 
 IZ 
 
 z 
 
 1 
 
 24 
 
 4 a 12 16 20 24 28 4 8 12 16 20 
 
 Si-OTHER ABYSSAL, pet Si-OTHER SEAMOUNTS. pot 
 
 Figure 26. — Silicon frequency distribution by environment for Pacific manganese nodules. 
 
 28 
 
35 
 
 -I 1 1 r- 
 
 18 
 
 12 
 
 y 9 
 
 n 
 
 2 3 4 5 
 
 Na-CC ZONE, pet 
 
 2 3 4 5 
 
 Na-OTHER ABYSSAL, pet 
 
 I 
 
 I I 1 
 
 10 
 
 1.5 3.0 4.5 6.0 7.5 9.0 10.5 
 
 Na-MID-PACIFIC SEAMOUNTS, pet 
 
 t 
 
 _j I I L__l L_i I I 
 
 2 3 4 5 
 
 Na-OTHER SEAMOUNTS, pel 
 
 Figure 27. — Sodium frequency distribution by environment for Pacific manganese nodules. 
 
36 
 
 500 1,000 1,500 2,000 2,500 3,000 
 
 Sr-CC ZONE, ppm 
 
 500 1,000 1,500 2,000 2,500 3,000 
 
 Sr-MID-PAORC SEAMOUNTS. ppm 
 
 40 
 
 35 - 
 
 8 ^ 
 
 u. 
 O 
 > 
 O 20 
 
 - 
 
 
 
 r- 
 
 
 
 
 
 
 
 
 -' 
 
 
 
 
 
 1 1 1 1 1 1 1 ■■■T 
 
 
 500 1,000 1,500 2.000 2,500 3,000 500 1,000 1,500 2,000 2,500 3,000 
 
 Sf-OTHER ABYSSAL, ppm Sr-OTHER SEAMOUNTTS. ppm 
 
 Figure 28. — Strontium frequency distribution by environment for Pacific manganese nodules. 
 
37 
 
 strontium to a certain extent. Strontium does not occur in the 
 feldspars based on the high negative correlation with Al, K, 
 and Si. 
 
 Strontium in CC-Zone area nodules correlates positively 
 with Ca, Cu, Mg, Mn, Ni, and Pb, and negatively with Al, K, 
 Na, Si, and Ti. In the MPS area, strontium is positively 
 correlated with Ca, Co, Mg, Mn, Pb, and Ti, and negatively 
 correlated with Na, Si, and Zr. In the other abyssal plains 
 area, strontium is correlated positively with Co, Fe, Pb, and 
 Ti, and negatively with Cr, K, and Si. In the other seamounts 
 area, strontium is correlated positively with Ba and Ca and 
 negatively with Al, K, Mg, and Si. 
 
 Titanium 
 
 Titanium concentrations in Pacific nodules vary from 
 <0.05 to 2.5 wt-pct, with a median value of 0.40 to 1.20 
 wt-pct and a weighted mean of 0.73 wt-pct based on 1,310 
 sample analyses. The median value for CC-Zone area 
 nodules is 0.40 to 0.50 wt-pct with a mean value of 0.53 
 wt-pct. Titanium values are similar in the CC-Zone area, in 
 the other abyssal plains area, and in the other seamounts 
 area. The MPS area titanium values are about twice the 
 concentrations seen in the other areas, with a median value 
 of 1.10 to 1.20 wt-pct and a mean of 1.12 wt-pct. Figure 29 
 provides histograms that show titanium distribution in each of 
 the four areas. 
 
 Titanium in Pacific nodules appears to be associated with 
 the iron phases present based on the positive correlation 
 (table 19) obtained with Fe and Co and negative correlation 
 with Mn, Cu, and Ni. The ionic radius of Ti"* is similar to that 
 of Fe^ and may allow it to substitute for Fe. Titanium has 
 also been observed in nodules as ilmenite, rutile, and 
 anatase. 
 
 Titanium in CC-Zone area nodules is correlated positively 
 with Co, Fe, Na, Pb, and Zr, negatively correlated with Cu, 
 Mg, Mn, and Ni, and slightly negative with Sr and Zn. In the 
 MPS area, titanium correlated positively with Al, Co, Cr, Fe, 
 Pb, Sr, and Zr, and negatively with Na, V, and Zn. In the other 
 abyssal plains area, titanium is correlated positively with Fe 
 and Sr and has no negative correlation. In the other 
 seamounts area, titanium is correlated positively with Co, Fe, 
 Pb, and V, and negatively with Ba, Ca, and Cr. The number 
 of sample analyses in the two seamounts areas is limited; 
 therefore, correlation coefficients may not reflect the actual 
 correlation of titanium to other elements. 
 
 Zirconium 
 
 Zirconium concentrations in Pacific nodules vary from 
 <0.005 to 0.20 wt-pct, with a median value of 0.03 to 0.075 
 wt-pct and a weighted mean of 0.058 wt-pct based on 304 
 sample analyses. The median value for CC-Zone area 
 nodules is 0.03 to 0.04 wt-pct with a mean value of 0.035 
 wt-pct. The CC-Zone nodules have the lowest zirconium 
 
 levels of the four areas; about one-half the levels of the other 
 three areas. The median range for the other three areas is 
 0.40 to 0.075 wt-pct with mean values from 0.054 to 0.062 
 wt-pct. Figure 30 provides histograms that show zirconium 
 distribution in each of the four areas. 
 
 Zirconium appears to occur in Pacific nodules in associa- 
 tion with the iron phases based on its strong negative 
 correlations (table 19) with Mn, Cu, and Ni and positive 
 correlations with Co and Fe. The ionic radius of Zr** is similar 
 to that of Fe^* and may allow some substitution in the iron 
 phases. 
 
 Zirconium in CC-Zone area nodules is correlated positively 
 with Fe and Ti and negatively with Cr, Cu, and Zn. In the MPS 
 area, zirconium is correlated positively with Al, Co, Fe, Si, 
 and Ti, slightly positive with Mn, and negatively with Ba, Cr, 
 Cu, Mg, Pb, Sr, and Zn. In the other abyssal plains area, 
 zirconium is correlated positively with Fe and negatively with 
 Cr and Si. In the other seamounts area, zirconium is 
 correlated positively with Al and Fe and exhibits no negative 
 correlations. 
 
 General Observations 
 
 The two abyssal plains areas have the higher levels of Al, 
 K, Si, and Na by about a factor of two over the two 
 seamounts areas. In contrast, the two seamounts areas have 
 higher Ca and Sr by the same factor. Magnesium, titanium, 
 and zirconium values are relatively uniform with the CC-Zone 
 area having the lowest zirconium values and the MPS area 
 having the highest titanium values. 
 
 ELEMENTS OF 
 
 ENVIRONMENTAL 
 
 INTEREST 
 
 Any of the following eight elements — As, Ba, Cd, Cr, Pb, 
 Hg, Se, Ag — when leached from wastes under conditions 
 specified by the U.S. Environmental Protection Agency, will 
 result in the waste being classified as a hazardous material, if 
 their concentrations are greater than 100 times the National 
 Drinking Water Standard. Data for Ba, Cd, Cr, and Pb are 
 presented in table 9, by area, as in the previous sections. 
 Data for the remaining elements (As, Hg, Se, and Ag), along 
 with the other four listed in table 9, are presented in table 10 
 as a composite for Pacific Ocean nodules. Correlation 
 coefficients are given in table 19. These data are taken from 
 the Sediment Data Bank (44, 48-50) as well as from Toth 
 (123), Harhs (67), and from analytical studies sponsored by 
 the Bureau of Mines. 
 
 Arsenic 
 
 Arsenic concentrations in Pacific nodules vary from 20 to 
 540 ppm, with a median value of 164 ppm and a mean value 
 
 Table 9. — Distribution of elements of environmental interest in Pacific manganes nodules, by area 
 
 Area 
 
 Range 
 
 . . ^ Standard de- 
 Median ^^.^"- viation of 
 ** mean, nx 
 
 Number 
 
 of 
 samples 
 
 Range 
 
 Median ^f^ 
 
 Standard de- 
 viation of 
 mean, ax 
 
 Number 
 
 of 
 samples 
 
 
 
 Barium, wt-pct 
 
 
 
 
 Chromium, 
 
 ppm 
 
 
 Clarion-Clipperton zone 
 
 Mid-Pacific seamounts 
 
 <0.01 - 0.76 
 .04 - .68 
 <0.005- 0.800 
 0.06 - 0.80 
 
 0.20- 0.22 0.28 
 .18- .20 .30 
 .14- ,16 .20 
 .32- .34 .37 
 
 ND 
 
 0.27 
 
 18 
 
 .33 
 
 213 
 39 
 
 499 
 59 
 
 1- 150 
 1- 40 
 1- 150 
 1- 130 
 
 15- 20 27 
 10- 20 58 
 15-20 25 
 30- 40 60 
 
 ND 
 
 147 
 
 38 
 
 129 
 
 107 
 22 
 
 Other abyssal plains, >3,000 m . 
 Other seamounts, <3,000 m 
 
 227 
 38 
 
 
 
 Cadmium, ppm 
 
 
 
 Lead, ppm 
 
 Clarion-Clipperton zone 
 
 Mid-Pacific seamounts 
 
 1 -35 
 1 -25 
 1 -35 
 1 -35 
 
 10 -15 123 
 5 -10 8.3 
 5 -10 10.7 
 5 -10 10.2 
 
 ND 
 7.6 
 7.1 
 8.2 
 
 127 
 15 
 
 133 
 23 
 
 50-1,800 
 
 100-4,700 
 
 50-3,000 
 
 50-3,000 
 
 400- 500 450 
 1,700-1,800 1,860 
 
 700- 800 820 
 1,000-1,100 1,030 
 
 190 
 950 
 710 
 770 
 
 921 
 105 
 
 Other abyssal plains, >3,000 m , 
 Other seamounts, < 3,000 m 
 
 1,185 
 206 
 
 ND Not determined. 
 
 
 
 
 
 
 
 
 
38 
 
 72 
 
 64 
 
 56 
 
 48 
 
 8 
 
 1 
 
 1 1 1 1 
 
 11 I— 1 r— 1 n 
 
 32-1— — 1 
 
 24 - 
 
 0.4 0.8 1.2 1.6 2.0 2.4 
 
 Ti-CC ZONE, pet 
 120 
 
 108 
 
 98 
 
 84 
 
 72 
 
 60 
 
 48 
 
 36 - 
 
 24 
 
 12 
 
 
 0.4 0.8 1.2 1.6 2.0 2.4 
 
 Ti-MID-PACIRC SEAMOl^fTS, pet 
 
 16 
 
 14 
 
 12 
 
 10 - 
 
 o 
 
 8 
 
 >- 
 
 o 
 
 -I 1 1 1 r 
 
 0.4 0.8 
 
 1.2 
 
 1.6 
 
 2.0 2.4 
 
 0.4 O.B 1.2 1.6 2.0 2.4 
 
 Ti-OTHER ABYSSAL, pet TI-OTHER SEAMOUNTS, pet 
 
 Figure 29 Titanium frequency distribution by environment for Pacific manganese nodules. 
 
39 
 
 10 
 
 1 
 
 1 1 1 1 1 
 
 16 
 14 
 
 - 
 
 - 
 
 12 
 10 
 
 - 
 
 - 
 
 6 
 
 - 
 
 - 
 
 A 
 
 - 
 
 - 
 
 2 
 
 - 
 
 - 
 
 
 — 
 
 1 1 J 
 
 Hi 2 
 
 o 
 
 
 300 600 900 1,200 1,500 1,800 2,100 
 
 Zr-CC ZONE, ppm 
 
 300 600 900 1,200 1,500 1,800 2,100 
 
 Zr-MID-PACIFIC SEAMOUNTS, ppm 
 
 36 
 
 32 - 
 
 28 - 
 
 24 
 
 20 
 
 "T" 
 
 1 
 
 1-1 l-l 
 
 300 600 900 1,200 1,500 1,800 2,100 
 
 Zr-OTHER ABYSSAL , ppm 
 
 6 - 
 
 
 300 600 900 1,200 1,500 1,800 2,100 
 
 Zr-OTHER SEAMOUNTS, ppm 
 
 Figure 30. — Zirconium frequency distribution by environment for Pacific manganese nodules. 
 
40 
 
 Table 10. — Distribution of elements of environ- 
 mental interest in Pacific manganese nodules, 
 composite 
 
 Element 
 
 Range 
 
 Range of 
 medians 
 
 Weighted 
 mean 
 
 Number of 
 samples 
 
 Arsenic .... ppm 
 
 20-540 
 
 164 
 
 159 
 
 122 
 
 Barium . . wt-pct 
 
 . <0.005-0.800 
 
 0.140-O.340 
 
 0.24 
 
 810 
 
 Cadmium . . ppm 
 
 1.0-35 
 
 5-15 
 
 11 
 
 298 
 
 Chromium . ppm 
 
 1.0-150 
 
 10-40 
 
 31 
 
 394 
 
 Lead ppm 
 
 50-^,700 
 
 400-1 ,800 
 
 742 
 
 2,417 
 
 Mercury . . . ppm 
 
 0.002-0.78 
 
 0.085 
 
 0.15 
 
 68 
 
 Selenium . . ppm 
 
 30-77 
 
 53 
 
 52 
 
 56 
 
 Silver ppm 
 
 0.001-0.68 
 
 0.039 
 
 0.10 
 
 56 
 
 of 159 ppm based on 118 sample analyses. Arsenic 
 concentrations are generally lower in the CC-Zone area and 
 higher in the seamounts area. The highest arsenic values 
 appear in the other abyssal areas. Figure 31 is a histogram 
 for Pacific nodules showing arsenic distribution. 
 
 Arsenic occurs in Pacific nodules in association with iron 
 and may be part of the iron phase structure. Arsenic is 
 probably oxidized to the As^* state in nodules. Arsenic is 
 correlated positively with Fe, Co, and Pb, with the strongest 
 correlation occurring in CC-Zone area nodules. 
 
 20 
 
 16 
 
 12 
 
 4 - 
 
 
 50 
 
 100 150 200 250 300 350 400 450 
 
 As-PACIFIC OCEAN, ppm 
 
 Figure 31 . — Arsenic frequency distribution for 
 Pacific manganese nodules. 
 
 Barium 
 
 Barium concentrations in Pacific nodules vary from <0.005 
 to 0.800 wt-pct, with a median value of 0.14 to 0.34 wt-pct 
 and a weighted mean of 0.24 wt-pct based on 810 sample 
 analyses. The median value for CC-Zone area nodules is 
 0.20 to 0.22 wt-pct with a mean value of 0.28 wt-pct. The two 
 abyssal plains areas have lower barium values than the two 
 seamounts areas. Figure 32 provides histograms that shows 
 barium distribution in each of the four areas. 
 
 Barium in Pacific nodules occurs as barite and also 
 substitutes into the structure of certain manganese minerals. 
 Barium in CC-Zone area nodules is correlated positively 
 (table 19) with Al and Na and negatively with Ca. Some 
 indications are that barium is positively correlated in 
 CC-Zone area nodules with Mn, Ni, Cu, and Zn based on a 
 selected analysis of 22 samples in this area. In the MPS 
 area, barium is correlated positively with Co, Na, Pb, and Zn, 
 and negatively with Fe and Zr. In the other abyssal plains 
 area, barium is positively correlated only with Cd. In the other 
 seamounts area, barium is positively correlated with Cd, Mg, 
 Mn, and Sr, and negatively with Fe, Si, Ti, and V. 
 
 Cadmium 
 
 Cadmium concentrations in Pacific nodules vary from 1 to 
 35 ppm, with a range of median values for the different areas 
 of 5 to 1 5 ppm and a mean value of 1 1 ppm based on 298 
 sample analyses. The median value for CC-Zone area 
 nodules is 10 to 15 ppm with a mean of 12 ppm. Cadmium is 
 higher for CC-Zone area nodules than for other areas but 
 only marginally. Figure 33 provides histograms that show 
 cadmium distribution in each of the four areas. 
 
 Cadmium levels in nodules are enriched over the sediment 
 levels in deep sea clays. Cadmium appears to be part of the 
 manganese mineral structure and may substitute in or fill the 
 tunnels of these structures. 
 
 Cadmium in CC-Zone area nodules is correlated positively 
 (table 19) with Ca, Cu, Mn, Mo, and Ni, and negatively with 
 Al, Co, Fe, Na, and Pb. In the MPS area, cadmium does not 
 correlate with any element based on a limited number of 
 sample analyses. In the other abyssal plains area, cadmium 
 is correlated positively with Ba, Cu, Mg, Mn, Mo, and Ni, and 
 negatively with Al, Co, Fe, K, Na, and Pb. In the other 
 seamounts area, cadmium is correlated positively with Ba, 
 Ca, Cu, Ni, and Zn, and negatively with Co, Cr, Mn, and Pb. 
 
 Chromium 
 
 Chromium concentrations in Pacific nodules vary from 1 to 
 150 ppm, with a median value of 10 to 40 ppm and a 
 weighted mean of 31 ppm based on 394 sample analyses. 
 The median value for CC-Zone area nodules is 15 to 20 ppm 
 with a mean value of 27 ppm. The CC-Zone and other 
 abyssal plains areas contain the lower chromium values by 
 about a factor of two compared with the two seamounts 
 areas. The medians, however, show that all areas are similar 
 with some increased chromium levels in the other seamounts 
 area. Figure 34 provides histograms that show chromium 
 distribution in each of the four areas. 
 
 Chromium occurs in Pacific nodules associated with the 
 gangue minerals, possibly the silicates, because of its 
 tendency to be positively correlated (table 19) with Si. 
 Chromium content in nodules is considerably lower than in 
 deep-sea clays or oceanic basalts and is generally associ- 
 ated in nodules with the entrapped sediment or other 
 extraneous phases. 
 
 Chromium in CC-Zone area nodules is correlated positive- 
 ly with no elements and negatively with Zr. In the MPS area, 
 chromium is correlated positively with Al, Cu, Mg, Ni, Si, and 
 Ti, and negatively with Ca, Na, and Zr based on a very limited 
 number of sample analyses. In the other abyssal plains area, 
 chromium is correlated positively with Si and negatively with 
 Na, Sr, and Zr. In the other seamounts area, chromium is 
 correlated positively with Fe and K and negatively with Al, 
 Cd, Na, and Ti based on a limited number of sample 
 analyses. 
 
 Lead 
 
 Lead concentrations in Pacific nodules vary from 50 to 
 4,700 ppm, with a range of median values for the different 
 areas in the Pacific of 400 to 1 ,800 ppm and a weighted 
 mean of 742 ppm based on 2,417 sample analyses. The 
 median value for CC-Zone area nodules is 400 to 500 ppm 
 with a mean of 450 ppm. This area contains the lowest lead 
 levels corresponding to the low iron levels in this area. The 
 other areas have two to three times this level of lead as 
 median and mean values. The highest values occur in the 
 MPS area with a median value of 1 ,700 to 1 ,800 ppm and 
 mean of 1 ,860 ppm. Figure 35 provides histograms that show 
 lead distribution in each of the four areas. 
 
 Lead is closely associated with iron in Pacific nodules, 
 based on high correlations (table 1 9) for these two elements, 
 and probably occurs in the amorphous iron phase. Lead in 
 CC-Zone area nodules is correlated positively with Co, Fe, 
 
41 
 
 26 
 24 
 22 
 20 
 
 18 
 
 8 
 
 u. 
 O 
 >- 12 
 
 o 
 
 10 
 
 54 
 
 36 - 
 
 O 30 
 
 U 
 
 O 
 
 u. 
 
 O 
 
 U 24 - 
 
 £ 18 
 
 12 
 
 ium 
 
 .12 .24 .36 .48 .60 .72 .84 
 
 Ba-CC ZONE, wt-pct 
 
 "T" 
 
 miwyw] n 
 
 .12 
 
 .24 
 
 .36 
 
 .48 
 
 .60 
 
 .72 
 
 .12 .24 .36 .48 .60 .72 
 
 Ba-UID-PACIFIC SEAMOUNTS, wt-pct 
 
 .84 
 
 
 .12 
 
 .24 
 
 .72 
 
 .84 
 
 Ba-OTHER ABYSSAL, wt-pct Ba-OTHER SEAMOUNTS. wt-pct 
 
 Figure 32. — Barium frequency distribution by environment for Pacific manganese nodules. 
 
42 
 
 42 
 
 10 20 30 
 
 Cd-CC ZONE, ppm 
 
 
 M 
 
 1 1 1 
 
 
 48 
 
 - 
 
 
 - 
 
 
 42 
 
 - 
 
 
 - 
 
 1 
 
 36 
 
 30 
 
 - 
 
 
 - 
 
 fe 
 
 
 
 
 
 
 
 
 >- 
 o 
 
 24 
 
 
 
 
 ~ 
 
 lU 
 
 u. 
 
 
 
 18 
 
 
 
 
 
 
 12 
 
 - 
 
 
 
 
 
 - 
 
 
 6 
 
 - 
 
 
 
 
 
 
 - 
 
 
 
 
 
 1 
 
 10 20 30 
 
 Cd-OTHER ABYSSAL, ppm 
 
 40 
 
 
 "! 
 
 
 1 
 
 " 
 
 
 
 5 - 
 
 
 1 
 
 j 
 1 
 
 UJ 
 
 o 
 
 z 
 
 o 
 o 
 o 
 
 4 ^ 
 3 - 
 
 
 
 
 ^ 
 
 o 
 
 
 
 >- 
 o 
 
 o 
 
 
 
 
 
 j 
 
 I 
 
 Li. 
 
 2 • 
 
 i 
 
 iL 
 
 
 
 
 1 
 
 10 20 30 
 
 Cd-MID-PACIFIC SEAMOUNTS, ppm 
 
 40 
 
 T 1 
 
 10 20 30 
 
 Cd-OTHER SEAMOUNTS. ppm 
 
 40 
 
 Figure 33. — Cadmium frequency distribution by environment for Pacific manganese nodules. 
 
43 
 
 X 60 90 120 150 
 
 Cr-CC ZONE, ppm 
 
 120 150 
 
 o 
 o 
 
 8 
 
 u. 4 
 O 
 
 >- 
 
 o 
 
 s 
 
 3 - 
 
 
 10 
 
 6 - 
 
 2 - 
 
 30 60 90 120 
 
 Cf-MID-PACIFIC SEAMOUNTS, ppm 
 
 30 
 
 60 
 
 90 120 
 
 150 
 
 
 150 
 
 Cr-OTHER ABYSSAL, ppm Cr-OTHER SEAMOUNTS, ppm 
 
 Figure 34. — Chromium frequency distribution by environment for Pacific manganese nodules. 
 
44 
 
 O.OS 0.10 0.15 0.20 
 
 Pb-CC ZONE, pet 
 
 0.2b 
 
 0.30 
 
 
 1 1 I ■ 1 1 
 
 108 - |-| 
 
 - 
 
 96 - "1 
 
 - 
 
 84-1- 
 
 - 
 
 72 - 
 
 _ 
 
 
 ffl 
 
 60 - 
 
 - 
 
 48 - 
 
 - 
 
 36 - 
 
 - 
 
 
 1 n 
 
 24 = 
 
 - 
 
 12 - 
 
 -1 
 
 
 - -\Wkj] . 
 
 0.08 
 
 0.24 
 
 0.32 
 
 0.40 0.48 
 
 0.08 0.18 0.24 0.32 0.40 
 
 Pb-MID-PACIFIC SEAMOUNTS, pet 
 
 0.48 
 
 18 I — 
 
 0.05 0.10 0.15 0.20 0.25 0.30 
 
 Pb-OTHER ABYSSAL, pd Pb-OTHER SEAMOUNTS, pet 
 
 Figure 35. — Lead frequency distribution by environment for Pacific manganese nodules. 
 
45 
 
 Sr, and Ti, and negatively with Cd, Cu, and Zn. In the MPS 
 area, lead is correlated positively with Ba, Co, Mg, Mn, Sr, 
 and Ti, and negatively with K, Na, Si, V, and Zr. In the other 
 abyssal plains area, lead is correlated positively with Fe and 
 Sr and negatively with Cd and Cu. In the other seamounts 
 area, lead is correlated positively with Co, Mo, and Ti, and 
 negatively with Cd. 
 
 Mercury 
 
 Mercury concentrations in Pacific nodules vary from 0.002 
 to 0.78 ppm, with a median value of 0.085 ppm and a mean 
 of 0.15 ppm based on a limited 68 sample analyses. These 
 very low levels are of little consequence with respect to 
 environmental issues. Figure 36 is a histogram for Pacific 
 nodules showing mercury distribution. 
 
 Mercury occurs at levels equal to or less than the 
 surrounding sediments. It most likely is associated in the iron 
 structure as mercury is significantly correlated only with iron 
 based on the very limited amount of data available. 
 
 20 
 
 16 - 
 
 12 - 
 
 8 - 
 
 rip 
 
 .05 .10 
 
 .35 .40 
 
 .45 
 
 .15 .20 .25 .30 
 Hg-PACIFIC OCEAN, ppm 
 
 Figure 36 Mercury frequency distribution for 
 
 Pacific manganese nodules. 
 
 Selenium 
 
 Selenium concentrations in Pacific nodules vary from 30 to 
 77 ppm with a median value of 53 ppm and a mean of 52 ppm 
 based on only 56 sample analyses obtained from Bureau of 
 Mines analyses. Indications are that these values may be as 
 much as a factor of 1 high based on limited information from 
 other nodules that are under study. Therefore, these values 
 may not be representative of the true levels in nodules and 
 should be used with caution until more data become 
 available. CC-Zone area nodules appear to have somewhat 
 lower concentrations of selenium than other nodules. Further 
 study is required to determine if these values are representa- 
 tive of all Pacific nodules. Figure 37 is a histogram for Pacific 
 nodules showing selenium distribution. Selenium does not 
 appear to be correlated with any major or minor element. 
 
 Silver 
 
 Silver concentrations in Pacific nod'iles vary from 0.001 to 
 0.68 ppm, with a median value of 0.039 ppm and a mean 
 value of 0.10 ppm based on 56 sample analyses. Silver 
 concentrations are equal to or less than silver concentrations 
 of deep-sea clays. No interelement correlations are found for 
 silver. Figure 38 is a histogram for Pacific nodules showing 
 silver distribution. 
 
 20 
 
 16 
 
 12 - 
 
 10 20 30 40 50 60 70 80 
 
 Se-PACIFIC OCEAN, ppm 
 
 Figure 37. — Selenium frequency distribution for 
 Pacific manganese nodules. 
 
 28 
 
 24 
 
 20 
 
 U 
 
 Z 
 lU 
 
 oc 
 
 5 16 
 
 o 
 
 o 
 
 o 
 
 4 - 
 
 £H] 
 
 f~l !~l FT 
 
 .05 .10 .15 .20 .25 .30 .35 .40 .45 
 
 Ag-PACIFIC OCEAN, ppm 
 
 Figure 38. — Silver frequency distribution for 
 Pacific manganese nodules. 
 
 General Observations 
 
 Nodules are enriched in As, Cd, Pb, and Se relative to their 
 concentrations in deep-sea clays. The elements Ba, Cr, Hg, 
 and Ag occur in Pacific nodules at levels similar to or less 
 than corresponding levels of these elements reported for 
 deep-sea clays. 
 
 In Pacific nodules, Ba and Cd are correlated with the Mn 
 phases, and As, Pb, and Hg are correlated with the Fe 
 phases. Barium may also occur as barite in the gangue 
 minerals. Chromium appears to be correlated with silicon and 
 may occur with entrapped sediments. No correlations for 
 selenium and silver were noted. 
 
 The CC-Zone area and other abyssal plains areas contain 
 
46 
 
 the lowest Cr, Pb, and Se levels and the highest levels of Ba 
 and Cd. The highest lead values occur in the MPS area. 
 
 Data tor As, Hg, be, and Ag are very limited; most of these 
 data were generated for this report from selected nodule 
 samples. Data for Ba, Cd, Cr, and Pb are more prevalent, 
 and interpretations of these data are made with greater 
 confidence. Based on the available information, the concen- 
 trations of many of these elements are too low to warrant 
 environmental interest. 
 
 RARE-EARTH ELEMENTS 
 
 The elements examined in this section are hafnium and all 
 of the lanthanide series elements with the exception of 
 promethium. For Pr, Dy, and Er, only limited sample analyses 
 were available, and no histograms are provided. Figures 39 
 through 50 are histograms for those elements with greater 
 than 40 sample analyses. Data for these elements are 
 presented for the composite of the Pacific nodules as they 
 
 are too limited to present by area. Table 1 1 lists the elements 
 by atomic number with concentration range, median, mean, 
 and total number of samples. A majority of the data available 
 for these elements is from analysis of nodules taken from the 
 CC-Zone area. 
 
 100 200 300 
 
 U-PACFIC OCEAN, ppm 
 
 400 
 
 500 
 
 Figure 39.— Lanthanum frequency distribution 
 for Pacific manganese nodules. 
 
 28 
 
 24 
 
 20 
 
 16 
 
 12 
 
 4 - 
 
 ri 
 
 50 
 
 100 150 200 250 300 350 
 
 Nd-PACIFIC OCEAN, ppm 
 
 Figure 41. — Neoaymium frequency distribution 
 for Pacific manganese nodules. 
 
 28 
 
 24 
 
 20 
 
 16 - 
 
 O 
 
 >- 
 
 y 12 1- 
 
 mi 
 
 n , n 
 
 ifl 
 
 24 
 
 20 
 
 s « 
 
 12 
 
 4 - 
 
 n 
 
 800 1,200 1,600 2,000 2,400 2,800 3,200 
 Ce-PACIFIC OCEAN, ppm 
 
 10 
 
 20 30 40 50 60 70 
 
 Figure 40. — Cerium frequency distribution for 
 Pacific manganese nodules. 
 
 Sm-PACIFIC OCEAN, ppm 
 
 Figure 42. — Samarium frequency distribution 
 for Pacific manganese nodules. 
 
47 
 
 Table 11. — Rare-earth elements in Pacific 
 manganese nodules, parts per million 
 
 Element Range 
 
 Lanthanum 66- 979 
 
 Cerium 74-3,000 
 
 Praseodymium . . . 26- 46 
 
 Neodymium 60- 700 
 
 Samarium 14- 141 
 
 Europium 1- 27 
 
 Gadolinium 14- 53 
 
 Terbium 1- 11 
 
 Dysprosium 22- 42 
 
 Holmium 1- 8 
 
 Erbium 11- 27 
 
 Thulium 1- 9 
 
 Ytterbium 8- 100 
 
 Lutetium 1- 6 
 
 Hafnium 3- 14 
 
 Median 
 
 Mean 
 
 Number of 
 samples 
 
 130 
 
 157 
 
 151 
 
 345 
 
 530 
 
 131 
 
 34 
 
 36 
 
 8 
 
 141 
 
 158 
 
 96 
 
 32 
 
 35 
 
 115 
 
 7 
 
 9 
 
 115 
 
 33 
 
 32 
 
 57 
 
 5 
 
 5.4 
 
 104 
 
 32 
 
 31 
 
 18 
 
 4 
 
 4 
 
 66 
 
 19 
 
 18 
 
 18 
 
 2 
 
 2.3 
 
 41 
 
 17 
 
 20 
 
 171 
 
 2 
 
 1.8 
 
 76 
 
 5 
 
 6 
 
 96 
 
 28 
 
 24 
 
 20 
 
 16 
 
 12 
 
 
 1 
 
 
 1 
 
 
 
 1 1 
 
 1 1 
 
 - 
 
 40 
 
 - 
 
 
 
 36 
 
 - 
 
 
 
 
 - 
 
 32 
 
 - 
 
 
 
 
 - 
 
 28 
 
 - 
 
 
 
 
 
 - 
 
 24 
 
 - 
 
 
 
 
 
 
 _ 
 
 20 
 
 - 
 
 
 
 
 16 
 12 
 
 a 
 
 - 
 
 
 
 
 
 
 
 - 
 
 - 
 
 
 
 
 
 
 
 - 
 
 4 
 
 I ^ 
 
 
 
 
 
 1 1 
 
 1 1 1 
 
 
 26 
 
 2 6 10 14 18 22 
 
 Eu-PACIFIC OCEAN, ppm 
 
 Figure 43. — Europium frequency distribution for 
 Pacific manganese nodules. 
 
 16 
 
 10 
 
 20 30 40 50 
 
 Gd-PACIFIC OCEAN, ppm 
 
 60 
 
 Figure 44 — Gadolinium frequency distribution 
 for Pacific manganese nodules. 
 
 Tb-PACIFIC OCEAN, ppm 
 
 Figure 45. — Terbium frequency distribution for 
 Pacific manganese nodules. 
 
 22 
 
 1 
 
 
 1 I 
 
 20 
 
 - 
 
 
 - 
 
 18 
 
 - 
 
 
 - 
 
 16 
 
 - 
 
 
 - 
 
 14 
 
 - 
 
 
 
 - 
 
 12 
 
 - 
 
 
 
 
 
 - 
 
 10 
 
 
 
 - 
 
 8 
 
 - 
 
 
 
 
 
 - 
 
 6 
 
 - 
 
 
 
 
 
 - 
 
 4 
 
 - 
 
 
 
 
 
 
 - 
 
 2 
 
 
 
 
 - 
 
 r 
 
 
 
 1 
 
 2 4 6 8 
 
 Ho-PACIFIC OCEAN, ppm 
 
 Figure 46. — Holmium frequency distribution for 
 Pacific manganese nodules. 
 
48 
 
 20 
 16 
 12 
 
 
 
 r 
 
 
 
 
 8 
 4 
 
 
 J 
 
 - 
 
 
 
 , , r 
 
 Tm-PACIFIC OCEAN, ppm 
 
 Figure 47. — Thulium frequency distribution for 
 Pacific manganese nodules. 
 
 4U 
 
 36 
 
 
 I 1 
 
 32 
 
 
 - 
 
 28 
 
 
 
 - 
 
 24 
 
 
 - 
 
 20 
 
 
 
 - 
 
 16 
 
 
 
 - 
 
 12 
 
 
 
 - 
 
 8 
 
 
 
 
 - 
 
 4 
 
 
 
 
 - 
 
 
 1 1 
 
 2 4 6 
 
 Lu-PACIFIC OCEAN, ppm 
 
 Figure 49. — Lutetium frequency distribution for 
 Pacific manganese nodules. 
 
 52 
 
 
 1 1 
 
 1 
 
 
 n " 
 
 
 1 
 
 1 
 
 48 
 
 - 
 
 
 
 - 
 
 44 
 
 " 
 
 
 
 - 
 
 40 
 
 - 
 
 
 ^ 
 
 
 - 
 
 36 
 
 
 
 
 
 
 - 
 
 32 
 
 - 
 
 
 
 
 
 - 
 
 28 
 24 
 
 \- 
 
 
 
 
 
 - 
 
 20 
 
 
 
 
 
 
 - 
 
 16 
 
 - 
 
 
 
 
 
 - 
 
 12 
 
 
 
 
 
 1 
 
 - 
 
 4 
 
 - 
 
 ' 
 
 
 
 
 
 
 H 
 
 ' 
 
 n 
 
 1 — 1 
 
 10 20 30 40 50 60 70 80 
 
 Yb-PACIFIC OCEAN, ppm 
 
 Figure 48. — Ytterbium frequency distribution for 
 Pacific manganese nodules. 
 
 24 
 
 1 
 
 
 1 1 1 1 "1 
 
 22 
 
 - 
 
 
 " 
 
 20 
 
 - 
 
 
 
 - 
 
 18 
 
 - 
 
 
 
 - 
 
 16 
 
 - 
 
 
 
 - 
 
 14 
 
 - 
 
 
 
 - 
 
 12 
 
 - 
 
 
 
 - 
 
 10 
 8 
 6 
 4 
 2 
 
 - 
 
 
 
 
 
 
 - 
 
 ~ 
 
 
 
 
 
 
 
 
 
 
 
 1 1 
 
 HI-PACIFIC OCEAN, ppm 
 
 Figure 50. — Hafnium frequency distribution for 
 Pacific manganese nodules. 
 
49 
 
 The rare-earth values for Pacific nodules are primarily 
 based on three publications, Glasby (60), Piper and 
 Williamson (107), and Elderfield (41), plus data from the 
 Sediment Data Bank (48). Rare-earth element content of 
 nodules, with the exception of cerium, exhibits a decrease in 
 rare-earth content relative to seawater content with increas- 
 ing atomic number. Cerium shows a large enrichment 
 relative to other rare-earth elements because of its oxidation 
 to Ce"* in nodules and is associated primarily with the iron 
 phase. Other rare-earth elements occur as oxides in both the 
 iron and gangue phosphate phases. It has been reported that 
 total rare-earth element content of Pacific nodules increases 
 with increasing distance from land and is correlated with both 
 the iron and manganese contents of nodules (127). A 
 negative correlation of rare earths to silica content has also 
 been observed. Rare-earth elements are incorporated in 
 nodules mainly from seawater. Most variations of rare-earth 
 content of nodules can be explained by dilution of the iron 
 and manganese phases by silicate minerals. The rare earths 
 are preferentially incorporated into nodules due to hydrolysis 
 under oxidizing conditions (60). The rare-earth elements 
 (exclusive of cerium) occur in two phases, a phosphate 
 phase composed of fish debris and/or recrystallized biogenic 
 apatite, and the hydrous iron oxide phase with chemisorbed 
 phosphate. 
 
 PRECIOUS-METAL- 
 GROUP ELEMENTS 
 
 The elements in this section are those elements that are 
 classified as precious metals and/or platinum-group metals. 
 Very limited sample analyses are available for Au, Ir, Pd, Pt, 
 Re, and Ru (1, 45, 60, 112); therefore, no histograms are 
 presented. No data are available for Os and Rh, and Ag is 
 discussed with the elements of environmental interest. A 
 summary of the elemental composition of Pacific nodules for 
 the six elements is given in table 12. 
 
 Gold values show a positive correlation with silica content, 
 whereas iridium values show a negative correlation (60). 
 Gold and palladium are depleted in Pacific nodules 
 compared with deep sea sediments whereas iridium shows 
 an enrichment in nodules relative to deep sea sediments. 
 The ability for some of these elements to form stable anionic 
 species (gold and rhenium) in seawater may explain their 
 depletion in nodules. 
 
 Table 12. — Precious-metal-group elements in 
 
 Pacific manganese nodules, nanograms per 
 
 gram 
 
 Element 
 
 Range 
 
 Median 
 
 Mean 
 
 Number of 
 samples 
 
 Gold 
 
 0.13- 3.9 
 
 1.92 
 
 1.93 
 
 10 
 
 Iridium 
 
 0.2 
 
 - 23.1 
 
 4.3 
 
 9.1 
 
 11 
 
 Palladium 
 
 2.9 
 
 - 9.2 
 
 6.3 
 
 6.2 
 
 10 
 
 Platinum 
 
 <5 
 
 -145 
 
 110 
 
 97 
 
 5 
 
 Rhenium 
 
 
 <.2 
 
 NAp 
 
 NAp 
 
 2 
 
 Ruthenium 
 
 
 18 
 
 NAp 
 
 NAp 
 
 1 
 
 NAp Not applicable. 
 
 
 RADIC 
 ELE 
 
 ►ACTIVE 
 
 • 
 
 
 
 MENTS 
 
 
 Only limited data are available on the radioactive 
 elements, with only Ra, Th, and U being reported. Over 250 
 sample analyses are available for U and Th and nine values 
 for Ra. Table 13 gives the Ra, Th and U data available for 
 Pacific nodules. Figures 51 and 52 are histograms for 
 thorium and uranium, respectively. Data for these elements 
 were obtained from the Sediment Data Bank (48) and other 
 sources (12, 81, 83-88, 96, 102). 
 
 Table 13. — Radioactive elements in Pacific 
 manganese nodules 
 
 Element 
 
 Range 
 
 Median 
 
 Mean 
 
 Number of 
 samples 
 
 Radium . . pg/g . . 
 Thorium . . ppm . 
 Uranium, .ppm . 
 
 1.0- 35.7 
 5 -154 
 1 - 68 
 
 5.1 
 21 
 5 
 
 8.5 
 28 
 6.8 
 
 9 
 283 
 255 
 
 110 
 
 100 - 
 90 
 80 
 
 o 
 
 O 60 
 
 160 180 
 
 Th-PACIFIC OCEAN, ppm 
 
 Figure 51. — Thorium frequency distribution for 
 Pacific manganese nodules. 
 
 
 BU 
 
 1 1 1 1 1 
 
 1 1 
 
 1 
 
 
 70 
 
 - 
 
 1 1 
 
 
 
 - 
 
 >- 
 o 
 
 z 
 
 UJ 
 
 oc 
 
 (C 
 3 
 
 u 
 o 
 
 o 
 
 60 
 SO 
 
 - 
 
 1 
 
 
 
 
 
 - 
 
 u. 
 O 
 
 
 
 
 
 
 
 
 
 > 
 
 o 
 
 z 
 
 UJ 
 
 o 
 
 UJ 
 
 a: 
 
 U. 
 
 40 
 30 
 
 - 
 
 
 
 
 
 
 - 
 
 
 20 
 
 - 
 
 
 
 
 -n 
 
 
 
 - 
 
 
 10 
 
 — 
 
 
 
 
 
 
 
 
 - 
 
 
 
 
 
 
 
 
 
 
 
 1 ^r~ 
 
 h^ , 1 1 , 
 
 1 1 — 
 
 12 16 20 24 28 
 
 U-PACIFIC OCEAN, ppm 
 
 Figure 52 Uranium frequency distribution for 
 
 Pacific manganese nodules. 
 
50 
 
 The uranium and thorium content of Pacific nodules (and 
 other nodules) can be explained by coprecipitation from 
 seawater with the iron phase. Uranium and thorium content 
 of nodules is enriched over seawater and deep sea 
 sediments. Their concentration is highest near the top 
 surface interface with seawater and lowest at the bottom 
 surface interface with the sediment. The interior of nodules 
 has a concentration intermediate of the top and bottom 
 surfaces. 
 
 Several authors (81. 83, 85-87, 96) have suggested that a 
 relationship exists between the thorium and uranium content 
 of nodules and the water depth from which they are taken. 
 
 OTHER TRACE 
 ELEMENTS 
 
 The 1 7 elements in this section for which data are available 
 are Sb, Be, Bi, B, Cs, Ga, Ge, Li, Nb, Rb, Sc, Ta, Te, Tl, Sn, 
 W, and Y. Table 14 gives the available information on these 
 elements for Pacific nodules. Figures 53 through 60 are 
 histograms for those elements where greater than 40 sample 
 analyses are available. Data for these elements come from 
 the Sediment Data Bank (48) as well as other sources. 
 
 Table 14. — Other trace elements in Pacific 
 manganese nodules, parts per million 
 
 Element 
 
 Range 
 
 Median 
 
 Mean 
 
 Number of 
 samples 
 
 Antimony 14-72 36 37 
 
 Beryllium 2-15 .2 4 
 
 Bismuth 6-31 23 21 
 
 Boron 17 -1,655 221 273 
 
 Cesium <.50- 2.60 <.70 75 
 
 Gallium 2-72 6 11 
 
 Germanium 3-90 37 42 
 
 Lithium 23 -1,055 100 160 
 
 Niobium 6 - 150 80 74 
 
 Rubidium 5-60 15 15 
 
 Scandium 1-29 10 10 
 
 Tantalum 2-20 11 11 
 
 Tellurium 172 - 272 214 216 
 
 Thallium 2-675 160 169 
 
 Tin 2-450 80 108 
 
 Tungsten 26 - 120 80 76 
 
 Yttrium 17-950 111 133 
 
 103 
 
 29 
 
 13 
 
 94 
 
 7 
 
 39 
 
 4 
 
 25 
 
 42 
 
 43 
 
 159 
 
 4 
 
 17 
 
 141 
 
 87 
 
 7 
 
 132 
 
 24 
 
 1 1 
 
 , 1 1 
 
 
 r 
 
 
 
 
 
 
 
 - 
 
 Of the 17 elements in this section, only eight have more 
 than 40 sample analyses and only four have more than 100 
 sample analyses. Antimony is thought to be associated with 
 the manganese phase. These trace elements may occur with 
 any of the three phases and/or be present as a result of 
 seawater residue incorporation. 
 
 Thallium merits special attention as the most enriched 
 element in nodules when compared with deep sea sedi- 
 ments. An inverse correlation is observed between thallium 
 and silica content of nodules. Thallium as Th is stable in acid 
 and alkaline environments whereas TP* is stable only at low 
 pH and forms thallic hydroxide precipitate when TP" solutions 
 are made basic. Thallium probably exists in nodules as thallic 
 hydroxide, TI(0H)3. The nodule environment may oxidize the 
 Tl* in sediments and precipitate thallium as the hydroxide 
 {60). 
 
 m 
 
 100 200 300 400 500 600 700 800 900 
 
 B-PACIFIC OCEAN, ppm 
 
 Figure 54. — Boron frequency distribution for 
 Pacific manganese nodules. 
 
 " 14 
 
 80 
 
 140 
 
 Sb-PACIFIC OCEAN, ppm 
 
 Figure 53. — Antimony frequency distribution for 
 Pacific manganese nodules. 
 
 Nb-PACIFIC OCEAN, pprn 
 
 Figure 55 — Niobium frequency distribution for 
 Pacific manganese nodules. 
 
51 
 
 20 30 
 
 60 70 
 
 Rb-PACIFIC OCEAN, ppm 
 
 Figure 56 Rubidium frequency distribution for 
 
 Pacific manganese nodules. 
 
 
 45 
 
 1 1 1 1 1 1 
 
 1 
 
 
 
 40 
 
 
 
 
 
 
 tu 
 
 35 
 
 _ 
 
 
 
 
 
 . 
 
 o 
 
 z 
 
 UJ 
 
 
 
 
 
 
 
 
 u 
 
 30 
 
 " 
 
 
 
 
 
 " 
 
 o 
 
 Li. 
 
 o 
 
 25 
 
 - 
 
 
 
 
 
 
 - 
 
 > 
 
 
 
 
 
 
 — 1 
 
 
 
 
 z 
 
 UJ 
 
 o 
 
 20 
 
 - 
 
 
 
 
 
 
 
 - 
 
 IT 
 
 Li. 
 
 15 
 
 - 
 
 
 
 
 
 
 
 - 
 
 
 10 
 
 - 
 
 
 
 
 
 
 
 
 - 
 
 
 5 
 
 n 
 
 
 
 
 
 
 
 
 1 1 1 
 
 1 1 
 
 - 
 
 Se-PACIFIC OCEAN, ppm 
 
 Figure 57. — Scandium frequency distribution for 
 Pacific manaanes*^ nodules. 
 
 150 200 250 300 350 400 450 500 
 
 T|. PACIFIC OCEAN, ppm 
 
 50 100 150 200 250 300 350 400 450 500 
 
 Sn-PACIFIC OCEAN, ppm 
 
 Figure 59 — Tin frequency distribution for Pacil 
 ic manganese nodules. 
 
 
 100 150 200 250 300 
 
 Y-PACIFIC OCEAN, ppm 
 
 Figure 58 — Thallium frequency distribution for 
 Pacific manganese nodules. 
 
 Figure 60 Yttrium frequency distribution for 
 
 Pacific manganese nodules. 
 
 ANION-FORMING 
 ELEMENTS 
 
 The eight elements in this section occur almost exclusively 
 as anions in the chemical structure of Pacific nodules. These 
 elements are Br, C, CI, F, I, N, P, and S occurring as bromide, 
 carbonate, chloride, fluoride, iodide, nitrate, pho&phate, and 
 sulfate anions. The anions — chloride, fluoride, bromide, 
 iodide — present in nodules are primarily the result of 
 residues from evaporation of seawater. 
 
 Carbon occurs as carbonate In the form of gangue 
 minerals such as calcite and other carbonate minerals and as 
 entrapped organic matter. 
 
52 
 
 Phosphorus is present as phosphate minerals such as 
 apatite and calcium phosphate and is associated with the 
 iron phases. Shark teeth inclusions in nodules increase the 
 phosphate level substantially. Phosphorite pellets (apatite) 
 have been observed as nucleii and inclusions in manganese 
 nodules. 
 
 Sulfur as sulfate occurs in nodules in the form of barite 
 (BaS04) and other sulfate minerals. The sulfide form is not 
 very common in the oxidizing environment in which nodules 
 are formed. 
 
 Data for nitrogen as nitrate are limited; nitrate is 
 undoubtedly a residue from seawater. Table 1 5 is a summary 
 of the data available for these elements. 
 
 Table 15. — Anion-f orming elements in Pacific 
 manganese nodules, weight-percent 
 
 Number of 
 Range samples 
 
 Element Form 
 
 Bromine Br" 
 
 Carbon CO3" 
 
 Chlorine C[ 
 
 Fluorine F" 
 
 Iodine I 
 
 Nitrogen NO3 
 
 Phosphorus P20s 
 
 Sulfur S04~ 
 
 0.002-0.080 
 
 7 
 
 .30 -1.70 
 
 22 
 
 <.01 -1.10 
 
 10 
 
 <.01 - .05 
 
 6 
 
 <.01 - .25 
 
 7 
 
 <.01 - .18 
 
 6 
 
 <.01 -2.20 
 
 158 
 
 .07 -6.60 
 
 24 
 
 SUMMARY TABLES 
 
 This section of the report contains summary tables for the 
 21 major and minor elements for each of the four areas of the 
 Pacific. Table 16 is the summary table for the CC-Zone area, 
 the MPS area, the other abyssal plains area, and the other 
 seamounts area. Table 1 7 gives the composite composition 
 of all 74 elements discussed in this report. The mean values 
 in table 1 7 for the 21 major and minor elements (including Ba, 
 Cd, Cr, and Pb) are weighted averages based on the total 
 number of analyses from each area. The median range for 
 these elements is the lowest and highest median value for 
 the four areas for each element. Table 1 8 is a list of those 
 elements not included in this report owing to absence of data, 
 exclusive of inert gases and transuranium elements. Table 
 19 lists interelement correlation coefficients found for the 21 
 major and minor elements from the CC-Zone area, the MPS 
 area, the other abyssal plains area, and the other seamounts 
 area. 
 
 CROSS SECTION ANALYSIS 
 
 The variation of elemental composition in a nodule cross 
 section is shown in figures 61 through 65 and table 20. Figure 
 61 shows a cross section of a nodule and the analysis points. 
 
 Table 16. — Summary of major, minor, and some trace elements in Pacific manganese nodules, by 
 
 area 
 
 Element 
 
 Range 
 
 Median 
 
 Mean 
 
 Number 
 
 of 
 samples 
 
 Range 
 
 Median 
 
 Mean 
 
 Number 
 
 of 
 samples 
 
 Clarion-Clipperton zone 
 
 Other abyssal plains, >3,000 m 
 
 Aluminum wt-pct . 
 
 Barium wt-pct . 
 
 Cadmium ppm . 
 
 Calcium wt-pct. 
 
 Chromium ppm . 
 
 Cobalt wt-pct . 
 
 Copper wt-pct . 
 
 Iron wt-pct . 
 
 Lead wt-pct . 
 
 Magnesium wt-pct . 
 
 Manganese wt-pct . 
 
 Molybdenum wt-pct. 
 
 Nickel wt-pct . 
 
 Potassium wt-pct . 
 
 Silicon wt-pct . 
 
 Sodium wt-pct . 
 
 Strontium wt-pct . 
 
 Titanium wt-pct . 
 
 Vanadium wt-pct . 
 
 Zinc wt-pct . 
 
 Zirconium wt-pct . 
 
 Aluminum wt-pct . 
 
 Barium wt-pct . 
 
 Cadmium ppm . 
 
 Calcium wt-pct. 
 
 Chromium ppm . 
 
 Cobalt wt-pct . 
 
 Copper wt-pct . 
 
 Iron wt-pct . 
 
 Lead wt-pct . 
 
 Magnesium wt-pct . 
 
 Manganese wt-pct . 
 
 Molybdenum wt-pct . 
 
 Nickel wt-pct . 
 
 Potassium wt-pct . 
 
 Silicon wt-pct . 
 
 Sodium wt-pct . 
 
 Strontium wt-pct . 
 
 Titanium wt-pct . 
 
 Vanadium wt-pct . 
 
 Zinc wt-pct . 
 
 "Zirconium wt-pct . 
 
 0.5-8.0 
 
 2.5-3.0 
 
 2.9 
 
 234 
 
 <0.5-10.0 
 
 2.5-3.0 
 
 3.0 
 
 570 
 
 <0.01-O.76 
 
 0.20-0.22 
 
 0.28 
 
 213 
 
 <0,005-0.80 
 
 0.14-0.16 
 
 0.20 
 
 499 
 
 1-35 
 
 10-15 
 
 12.3 
 
 127 
 
 1-35 
 
 5-10 
 
 10.7 
 
 133 
 
 <0.5-18.0 
 
 1.5-2.0 
 
 1.7 
 
 872 
 
 <0.5-13.0 
 
 1.5-2.0 
 
 1.8 
 
 914 
 
 1-150 
 
 15-20 
 
 27 
 
 107 
 
 1-150 
 
 15-20 
 
 25 
 
 227 
 
 <0.1-0.9 
 
 0.20-0.30 
 
 0.24 
 
 1,925 
 
 <0.1-1.4 
 
 0.2-0.3 
 
 0.24 
 
 2,219 
 
 0.1-2.0 
 
 1.0-1.1 
 
 1.02 
 
 2,236 
 
 <0.05-2.00 
 
 0.30-0.40 
 
 0.42 
 
 2,282 
 
 1-25 
 
 6-7 
 
 6.9 
 
 2,215 
 
 1-25 
 
 12-13 
 
 12.7 
 
 2,325 
 
 0.005-O.18 
 
 0.040-0.050 
 
 0.045 
 
 921 
 
 0.005-0.30 
 
 0.07-0.08 
 
 0.082 
 
 1,185 
 
 <0.25-3.0 
 
 1.50-1.75 
 
 1.65 
 
 209 
 
 <0.25-5.00 
 
 1.25-1.50 
 
 1.43 
 
 361 
 
 1-39 
 
 26-27 
 
 25.4 
 
 2.227 
 
 1-40 
 
 18-19 
 
 18.5 
 
 2,354 
 
 <0.005-0.12 
 
 0.05-0.06 
 
 0.052 
 
 265 
 
 <0.005-0.13 
 
 0.03-0.04 
 
 0.036 
 
 746 
 
 0.1-2.0 
 
 1.3-1.4 
 
 1.28 
 
 2,237 
 
 0.1-2.0 
 
 0.50-0.60 
 
 0.63 
 
 2,334 
 
 0.20-3.0 
 
 0.80-0.90 
 
 1.01 
 
 123 
 
 0.10-3.0 
 
 0.70-0.80 
 
 0.93 
 
 335 
 
 1.0-25.0 
 
 6.0-6.5 
 
 7.6 
 
 339 
 
 0.5-25.0 
 
 7.0-8.0 
 
 8.8 
 
 460 
 
 0.5O-6.75 
 
 2.00-2.25 
 
 2.79 
 
 106 
 
 <0.25-5.75 
 
 1.75-2.00 
 
 2.07 
 
 297 
 
 <0.005-0.16 
 
 0.040-O.050 
 
 0.045 
 
 78 
 
 <0.005-0.18 
 
 0.07-0.08 
 
 0.077 
 
 320 
 
 0.10-2.20 
 
 0.40-0.50 
 
 0.53 
 
 265 
 
 <0.05-2.50 
 
 0.60-0.70 
 
 0.78 
 
 854 
 
 <. 005-0.08 
 
 0.040-0.050 
 
 0.047 
 
 70 
 
 0.01-0.30 
 
 0.04-0.05 
 
 0.048 
 
 370 
 
 <0.05-0.95 
 
 0.10-0.15 
 
 0.14 
 
 1,539 
 
 <0.05-0.95 
 
 0.05-0.10 
 
 0.09 
 
 1,285 
 
 0.010-0.09 
 
 0.030-0.040 
 
 0.035 
 
 33 
 
 <0.005-0.20 
 
 0.05-0.06 
 
 0.062 
 
 226 
 
 Mid-Pacific seamounts 
 
 
 Other seamounts, 
 
 <3,000 m 
 
 
 <0.25-6.00 
 
 0.04-0.68 
 
 1-25 
 
 <0, 5-25.0 
 
 1-40 
 
 <0.1-2.5 
 
 <0.01-1.00 
 
 2-25 
 
 0.01-0.47 
 
 0.50-3.50 
 
 1-40 
 
 <0.005-0.11 
 
 0.1-1.5 
 
 0.10-0.90 
 
 <0.5-15.0 
 
 0.50-5.50 
 
 <0.005-0.30 
 
 0.20-2.20 
 
 <0.005-0.30 
 
 <0.05-0.25 
 
 <0.005-0.110 
 
 0.25-0.75 
 
 0.18-0.20 
 
 5-10 
 
 2.0-2.5 
 
 10-20 
 
 0.7-0.8 
 
 <0.05 
 
 14.5-15.5 
 0.17-0.18 
 0.75-1.25 
 20-21 
 0.05-0.06 
 0.40-0.50 
 0.30-0.40 
 
 2.0-3.0 
 1.45-1.55 
 0.14-0.15 
 1.10-1.20 
 0.07-0.08 
 0.05-0.10 
 0.070-0.075 
 
 1.20 
 
 0.30 
 
 8.3 
 
 4.2 
 
 58 
 
 0.76 
 
 0.10 
 
 14.7 
 0.186 
 1.41 
 20.8 
 0.05 
 0.49 
 0.41 
 
 3.6 
 2.13 
 0.13 
 1.12 
 
 0.086 
 0.07 
 
 0.061 
 
 48 
 39 
 15 
 91 
 22 
 182 
 176 
 
 185 
 105 
 
 35 
 183 
 
 56 
 188 
 
 35 
 
 45 
 28 
 27 
 102 
 29 
 82 
 18 
 
 <0.5-7.0 
 
 0.06-0.80 
 
 1-35 
 
 <0.5-25.0 
 
 1-130 
 
 <0.05-1.40 
 
 <0.05-1.20 
 
 1-25 
 
 0.005-0.30 
 
 <0.25-4.25 
 
 1-40 
 
 <0.005-0.15 
 
 0.1-1.4 
 
 0.10-1.60 
 
 <0.5-23.0 
 
 0.25-3.75 
 
 <0.005-0.28 
 
 <0.05-1.60 
 
 <0.005-0.14 
 
 <0.05-0.55 
 
 <0.005-0.20 
 
 1.0-1.5 
 
 0.32-0.34 
 
 5-10 
 
 2.0-3.0 
 
 30-^0 
 
 0.20-0.30 
 
 <0.05 
 
 16-17 
 0.10-0.11 
 1.50-1.75 
 
 16-17 
 
 0.03-0.04 
 
 0.3-0.4 
 
 0.30-0.40 
 
 3.0-4.0 
 1.25-1.50 
 0.13-0.14 
 0.40-0.50 
 0.06-0.07 
 0.05-0.10 
 0.04-0.05 
 
 1.7 
 0.37 
 10.2 
 4.5 
 60 
 0.31 
 0.11 
 
 15.6 
 0.10 
 1.79 
 17.8 
 0.05 
 0.35 
 0.54 
 
 4.8 
 1.64 
 
 0.135 
 0.47 
 
 0.067 
 0.07 
 
 0.054 
 
 79 
 
 59 
 
 23 
 
 200 
 
 38 
 
 293 
 
 304 
 
 312 
 206 
 
 64 
 315 
 
 88 
 315 
 
 66 
 
 91 
 37 
 68 
 89 
 38 
 191 
 27 
 
53 
 
 Table 17. — Summary of elements in Pacific manganese nodules 
 
 Element and 
 atomic number 
 
 Range 
 
 Median Mean 
 
 Number 
 
 of 
 samples 
 
 Element and 
 atomic number 
 
 Range 
 
 Median Mean 
 
 Number 
 
 of 
 samples. 
 
 Aluminum 13. 
 
 Antimony 51 . 
 
 Arsenic 33. 
 
 Barium 56 . 
 
 Beryllium 4. 
 
 Bismutfi 83. 
 
 Boron 5 . 
 
 Bromine 35. 
 
 Cadmium 48. 
 
 Calcium 20. 
 
 Carbon' 6 . 
 
 Cerium 58 . 
 
 Cesium 55. 
 
 Cfilorine 17. 
 
 Cfiromium 24. 
 
 Cobalt 27. 
 
 Copper 29. 
 
 Dysprosium 66. 
 
 Erbium 68. 
 
 Europium 63. 
 
 Fluorine 9 . 
 
 Gadolinium 64. 
 
 Gallium 31 . 
 
 Germanium 32. 
 
 Gold 79. 
 
 Hafnium 72. 
 
 Holmium 67. 
 
 Iodine 53. 
 
 Iridium 77. 
 
 Iron 26 . 
 
 Lantfianum 57 . 
 
 Lead 82. 
 
 Lithium ; 3 . 
 
 Lutetium 71 . 
 
 Magnesium ... .12. 
 
 Manganese .... 25 . 
 Mercury 80 . 
 
 wt-pct 
 ..ppm 
 ..ppm 
 wt-pct 
 ..ppm 
 ..ppm 
 ..ppm 
 
 wt-pct 
 ..ppm 
 wt-pct 
 wt-pct 
 ..ppm 
 ..ppm 
 wt-pct 
 
 ..ppm 
 wt-pct 
 wt-pct 
 ..ppm 
 ..ppm 
 ..ppm 
 wt-pct 
 
 ..ppm 
 ..ppm 
 ..ppm 
 
 • • ng-'g 
 
 ..ppm 
 ..ppm 
 wt-pct 
 
 • ■ ng/g 
 wt-pct 
 ..ppm 
 wt-pct 
 ..ppm 
 ..ppm 
 wt-pct 
 
 wt-pct 
 
 • ■ ng/g 
 
 <0.25-10.00 
 
 14-72 
 
 20-450 
 
 <0.005-0.800 
 
 2-15 
 
 6-31 
 
 17-1,655 
 
 0.002-0.080 
 
 1-35 
 
 <0.05-25.00 
 
 0.30-1.70 
 
 74-3,000 
 
 <0.5-2.6 
 
 <0.01-1.10 
 
 1-150 
 
 <0.05-2.50 
 
 <0.01-2.00 
 
 22-42 
 
 11-27 
 
 1-27 
 
 <0.01-0.05 
 
 14-53 
 
 2-72 
 
 3-90 
 
 0.13-3.90 
 
 3-14 
 
 1-8 
 
 0.01-0.25 
 
 0.2-23.1 
 
 1-25 
 
 66-979 
 
 0.005-0.470 
 
 23-1 ,055 
 
 1-6 
 
 <0.25-5.00 
 
 1-40 
 2-775 
 
 0.25-2.00 2.80 
 
 36 37 
 
 164 159 
 
 0.140-0.340 0.239 
 
 2 4 
 
 23 21 
 
 221 273 
 
 0.05 0.05 
 
 5-15 11 
 
 0.50-3.00 2.12 
 
 0.19 0.18 
 
 345 530 
 
 <0.7 0.75 
 
 0.86 0.07 
 
 10-^0 31 
 
 0.20-0.80 0.44 
 
 <0.05-1.10 0.66 
 
 32 31 
 
 19 18 
 
 7 9 
 
 <0.01 0.013 
 
 33 
 6 
 
 37 
 
 1.92 
 
 5 
 
 4 
 
 32 
 
 11 
 
 42 
 
 1.93 
 
 6 
 
 4 
 
 0.023 0.051 
 
 4.3 9.1 
 
 6-17 10.4 
 
 130 157 
 
 0.040-0.180 0.072 
 
 100 160 
 
 2 1.8 
 
 0.75-1.75 1.53 
 
 16-27 
 85 
 
 21.6 
 152 
 
 931 Molybdenum . . .42. 
 
 103 Neodymium 60. 
 
 122 Nickel 28. 
 
 810 Niobium 41 . 
 
 29 Nitrogen^ 7. 
 
 13 Palladium 46, 
 
 94 Phospfiorus^ . . .15. 
 
 7 
 
 298 
 
 2,077 
 
 22 
 
 131 
 
 7 
 
 10 
 
 394 
 
 4,619 
 
 4,998 
 
 18 
 
 8 
 
 115 
 
 6 
 
 57 
 39 
 
 4 
 10 
 96 
 66 
 
 7 
 
 11 
 
 5,037 
 
 151 
 
 2,417 
 
 25 
 
 76 
 
 669 
 
 Platinum 78. 
 
 Potassium 19. 
 
 Praseodymium .59. 
 
 Radium 88. 
 
 Rhenium 75. 
 
 Rubidium 37. 
 
 Ruthenium 44. 
 
 Samarium 62. 
 
 Scandium 21 . 
 
 Selenium 34. 
 
 Silicon 14. 
 
 Silver 47. 
 
 Sodium 11 . 
 
 Strontium 38. 
 
 Sulfur^ 16. 
 
 Tantalum 73. 
 
 Tellurium 52. 
 
 Terbium 65. 
 
 Thallium 81 . 
 
 Thorium 90. 
 
 Thulium 69. 
 
 Tin 50. 
 
 Titanium 22. 
 
 Tungsten 74. 
 
 Uranium 92. 
 
 Vanadium 23 . 
 
 Ytterbium 70. 
 
 Yttrium 39. 
 
 5,079 Zinc 30. 
 
 68 Zirconium 40. 
 
 wt-pct 
 ..ppm 
 wt-pct 
 ..ppm 
 wt-pct 
 • ■ ng/g 
 wt-pct 
 
 ■ • ng/g 
 wt-pct 
 
 ppm 
 
 pg/g 
 ng/g 
 
 ppm 
 
 ng/g 
 
 ppm 
 
 ppm 
 
 ppm 
 
 wt-pct 
 
 ■ • ng/g 
 wt-pct 
 wt-pct 
 
 wt-pct 
 ppm 
 ppm 
 ppm 
 ppm 
 ppm 
 ppm 
 
 .ppm 
 wt-pct 
 .ppm 
 .ppm 
 wt-pct 
 .ppm 
 .ppm 
 
 wt-pct 
 wt-pct 
 
 <0.005-0.150 
 
 60-700 
 
 0.10-2.00 
 
 6-150 
 
 <0.01-0.18 
 
 2.9-9.2 
 
 <0.01-2.2 
 
 5-145 
 
 0.10-3.00 
 
 26-46 
 
 1.0-35.7 
 
 <0.2 
 
 5-60 
 
 18 
 
 14-141 
 
 1-29 
 
 30-77 
 
 <0. 5-25.0 
 
 2-680 
 
 <0. 25-6.75 
 
 <0.005-0.300 
 
 0.07-6.6 
 
 2-20 
 
 172-272 
 
 1-11 
 
 2-675 
 
 5-154 
 
 1-9 
 
 2-450 
 
 <0.05-2.20 
 
 26-120 
 
 1-68 
 
 <0.005-0.300 
 
 8-100 
 
 17-950 
 
 <0.05-1.00 
 <0. 005-0.200 
 
 0.030-0.060 0.041 
 
 141 158 
 
 0.30-1.40 0.89 
 
 80 74 
 
 0.04 0.056 
 
 6.3 6.2 
 
 0.21 0.23 
 
 110 
 
 0.30-0.90 
 
 34 
 
 5.1 
 
 NAp 
 
 15 
 
 97 
 0.87 
 
 36 
 
 8.5 
 NAp 
 
 15 
 
 NAp NAp 
 
 32 
 10 
 53 
 2.0-8.0 
 39 
 
 35 
 10 
 52 
 7.8 
 101 
 
 1.25-2.25 2. 20 
 0.040-0.150 0.083 
 
 0.4 
 
 11 
 
 214 
 
 5 
 
 160 
 
 21 
 
 2 
 
 1.84 
 11 
 216 
 5.4 
 169 
 28 
 2.3 
 
 80 108 
 
 0.40-1.20 0.73 
 
 80 76 
 
 C fi ft 
 
 0.040-0.080 0.051 
 
 17 20 
 
 111 133 
 
 0.05-0.15 0.11 
 
 0.040-0.075 0.058 
 
 1,157 
 
 96 
 
 5,074 
 
 42 
 
 6 
 
 10 
 
 158 
 
 5 
 559 
 8 
 9 
 2 
 43 
 1 
 
 115 
 159 
 
 56 
 935 
 
 56 
 468 
 493 
 
 24 
 4 
 
 17 
 104 
 141 
 283 
 
 41 
 
 87 
 1,310 
 7 
 255 
 507 
 171 
 132 
 
 3,097 
 304 
 
 NAp Not applicable. 'As CO3 . ^as NOa". ^As PsOj. ''As SO4 
 
 Table 18. — Elements for which no data were found for Pacific manganese nodules (exclusive of 
 
 inert gases and transuranium elements) 
 
 Atomic number 
 
 Actinium 89 
 
 Astatine 85 
 
 Francium 87 
 
 Indium 49 
 
 Osmium 76 
 
 Atomic number 
 
 Polonium 84 
 
 Promethium 61 
 
 Protactinium 91 
 
 Rodium 45 
 
 Technetium 43 
 
 Table 19. — Interelement correlation coefficients for Pacific manganese nodules, by area 
 
 Element Al 
 
 Ba Ca Cd Co Cr Cu 
 
 Fe 
 
 K Mg Mn Mo Na 
 
 Pb 
 
 Sr 
 
 Zn 
 
 CLARION-CLIPPERTON ZONE 
 
 Al 1 
 
 Ba 34 
 
 Ca * 
 
 Cd -.49 
 
 Co * 
 
 Cr * 
 
 Cu 41 
 
 Fe * 
 
 K 63 
 
 Mg -.50 
 
 Mn -.52 
 
 Mo * 
 
 Na 67 
 
 Ni ♦ 
 
 Pb * 
 
 Si 53 
 
 Sr -.50 
 
 Tl * 
 
 V -.30 
 
 Zn * 
 
 Zr * 
 
 0.34 
 
 1 
 
 -.31 
 
 .40 
 
 -* 
 
 -0.49 
 
 * 
 
 -0.31 
 
 * 
 
 it 
 
 1 
 
 .33 
 
 ■k 
 
 .33 
 
 1 
 
 -O.30 
 
 * 
 
 -.30 
 
 1 
 
 * 
 
 -* 
 
 * 
 
 * 
 
 .42 
 
 * 
 
 * 
 
 -.30 
 
 .33 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 .31 
 
 * 
 
 ♦ 
 
 .45 
 
 * 
 
 ♦ 
 
 -.32 
 
 * 
 
 * 
 
 .57 
 
 * 
 
 * 
 
 -.44 
 
 .40 
 
 * 
 
 * 
 
 * 
 
 .56 
 
 * 
 
 • 
 
 ♦ 
 
 * 
 
 .36 
 
 .30 
 
 * 
 
 * 
 
 ■58 
 
 0.41 
 
 * 
 
 0.63 
 
 -0.50 
 
 -0.52 
 
 * 
 
 0.67 
 
 ■k 
 
 * 
 
 0.53 
 
 -0.50 
 
 * 
 
 -0.30 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 .40 
 
 •k 
 
 * 
 
 ir 
 
 -* 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 • 
 
 -* 
 
 it 
 
 •k 
 
 .56 
 
 * 
 
 .30 
 
 * 
 
 * 
 
 .42 
 
 -0.30 
 
 * 
 
 ♦ 
 
 .31 
 
 0.45 
 
 -.32 
 
 0.57 
 
 -0.44 
 
 ir 
 
 * 
 
 * 
 
 * 
 
 ♦ 
 
 * 
 
 * 
 
 .33 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 .40 
 
 ■k 
 
 * 
 
 0.36 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 -0.58 
 
 1 
 
 -.64 
 
 -.37 
 
 .63 
 
 .67 
 
 .39 
 
 -.48 
 
 .80 
 
 -.37 
 
 -.40 
 
 .66 
 
 -.59 
 
 .30 
 
 0.44 
 
 -.54 
 
 -.64 
 
 1 
 
 * 
 
 -.41 
 
 -.42 
 
 -.30 
 
 * 
 
 -.59 
 
 .54 
 
 * 
 
 * 
 
 .57 
 
 * 
 
 -.49 
 
 .74 
 
 -.37 
 
 * 
 
 1 
 
 -.51 
 
 -.59 
 
 * 
 
 .69 
 
 * 
 
 * 
 
 .40 
 
 -.44 
 
 * 
 
 * 
 
 * 
 
 
 .63 
 
 -.41 
 
 -.51 
 
 1 
 
 .69 
 
 • 
 
 -.62 
 
 .52 
 
 * 
 
 * 
 
 .63 
 
 -.34 
 
 * 
 
 * 
 
 
 .67 
 
 -.42 
 
 -.59 
 
 .69 
 
 1 
 
 .71 
 
 -.43 
 
 .75 
 
 * 
 
 -.57 
 
 .50 
 
 -.49 
 
 .37 
 
 .51 
 
 
 .39 
 
 -.30 
 
 * 
 
 * 
 
 .71 
 
 1 
 
 • 
 
 .63 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 
 -.48 
 
 * 
 
 .69 
 
 -.62 
 
 -.43 
 
 -* 
 
 1 
 
 * 
 
 1^ 
 
 .30 
 
 -.78 
 
 .36 
 
 -.36 
 
 * 
 
 
 .80 
 
 -.59 
 
 * 
 
 .52 
 
 .75 
 
 .63 
 
 * 
 
 1 
 
 * 
 
 -.41 
 
 .30 
 
 -.54 
 
 .36 
 
 .47 
 
 
 -.37 
 
 .54 
 
 if 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 1 
 
 ♦ 
 
 .49 
 
 .44 
 
 • 
 
 -.30 
 
 
 -.40 
 
 * 
 
 .40 
 
 * 
 
 -.57 
 
 * 
 
 .30 
 
 -.41 
 
 * 
 
 1 
 
 -.37 
 
 * 
 
 * 
 
 ♦ 
 
 
 .66 
 
 * 
 
 -.44 
 
 .63 
 
 .50 
 
 • 
 
 -.78 
 
 .30 
 
 .49 
 
 -.37 
 
 1 
 
 -.30 
 
 * 
 
 * 
 
 
 -.59 
 
 .57 
 
 * 
 
 -.34 
 
 -.49 
 
 * 
 
 .36 
 
 -.54 
 
 .44 
 
 * 
 
 -.30 
 
 1 
 
 * 
 
 -.30 
 
 ,42 
 
 .30 
 
 * 
 
 * 
 
 * 
 
 .37 
 
 * 
 
 -.36 
 
 .36 
 
 * 
 
 -* 
 
 * 
 
 * 
 
 1 
 
 * 
 
 * 
 
 .44 
 
 -.49 
 
 * 
 
 * 
 
 .51 
 
 • 
 
 * 
 
 .47 
 
 -.30 
 
 * 
 
 * 
 
 -.30 
 
 ♦ 
 
 1 
 
 -.43 
 
 -.54 
 
 .74 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 ♦ 
 
 .42 
 
 -* 
 
 -.43 
 
 1 
 
 ■ No significant correlation found. Coefficients ---0.3 or • 0.3 are considered significant 
 
54 
 
 Table 19. — Interelement correlation coefficients for Pacific manganese nodules, by area — Con. 
 
 Element Al Ba Ca Cd Co Cr Cu Fe K Mg Mn Mo Na Ni Pb Si Sr Ti 
 
 MID-PACIFIC SEAMOUNTS 
 
 Al 1 * * * -0.31 0.74 -0.31 * * 0.44 -0.53 -0.34 -0.34 -0.35 * * * 0.31 
 
 Ba * 1 * * .42 * * -0.45 * * * * .33 ♦ 0.44 * * * 
 
 Ca * * 1 * -.31 -.41 * -.60 * * -.46 ***** 0.61 * 
 
 Cd * * *1 * * * * * * * * * * * * * * 
 
 Co -.31 .42 -.31 * 1 * * * -0.41 ,53 .47 * -.34 .30 .74 -0.61 .61 .46 
 
 Cr 74 * -.41 * * 1 .31 * * .64 * * -.51 .33 * .40 * .59 
 
 Cu -.31 ****.311 *********** 
 
 Fe * —.45 -.60 ****1 ********* .46 
 
 K * * * * -.41 * * * 1 * * * .52 * -.32 .52 * * 
 
 Mg 44 * * * .53 .64 * * * 1 * * * .43 .67 * .44 * 
 
 Mn -.53 * -.46 * .47 ***** 1 .59 * .70 .54 * .39 * 
 
 Mo -34* * * * * * * * * .59 1 .33 .61 * * * * 
 
 Na -.34 .33 * * -.34 -.51 * * .52 * * .33 1 .54 -.33 .57 -.59 -.43 
 
 Ni -.35 * * * .30 .33 * * * .43 .70 .61 .54 1 * * * * 
 
 Pb * .44 * * .74 * * * -.32 ,67 .54 * -.33 * 1 -.40 .65 .31 
 
 Si * * * * -61 ,40 * * ,52 * * * ,57 * -,40 1 -,66 * 
 
 Sr * * ,61 * .61 * * * * ,44 ,39 * -,59 * ,65 -66 1 ,62 
 
 Ti 31 * * * .46 .59 * 46 * * * * -.43 * .31 * .62 1 
 
 V * * * * * * * * .46 * * -.52 .38 * -.31 * * -.30 
 
 2n * .57 * * * * * * * -.42 .43 * .69 .64 * * * -.34 
 
 Zr 68 -.38 * * .42 -.41 -.70 67 * -42 ,39 * * * -38 ,58 -.36 .59 
 
 OTHER ABYSSAL PLAINS, >3,000 m 
 
 Al 1 * * -0.52 -0,30 * * * 050 * -0.56 -0.30 * * * 065 * * 
 
 Ba *1 * .56* * * * * * * * * * * * * * 
 
 Ca * * 1 * * * * * * 0.30 ******** 
 
 Cd -.52 .56 * 1 -.48 * 0.84 -0,71 -,94 ,99 ,63 ,31 -0,77 0,85 -0,36 * * * 
 
 Co -,30 * * -,48 1 **, 36 ******* -,44 0,48 * 
 
 Cr * * * * * 1 * * * * * * -.34 * * .57 -.35 ♦ 
 
 Cu * * * .84 * * 1 -.53 * * ,58 * * ,82 -,30 * * * 
 
 Fe * * * -.71 .36 * -53 1 -,32 * -,36 * * -.49 .37 * .51 0.30 
 
 K 50 * * -.94 * * * -.32 1 * -.33 * * * * ,55 -31 * 
 
 Mg * * ,30, 99* * * * *1 * * * * * * * * 
 
 Mn -.56 * * .63 * ♦ ,58 -,36 -.33 * 1 .45 * .66 * -.62 * * 
 
 Mo -.30 * * .31 ****** ,45 1 * .36 * -.34 * * 
 
 Na * * * -.77 * -34 ******i ***** 
 
 Ni * * * ,85 * * .82 -.49 * * .66 .36 * 1 * -.30 * * 
 
 Pb * * * -.36 * * -.30 .37 ****** 1 * ,31 * 
 
 Si 65 * * * -,44 ,57 * * ,55 * -.62 -.34 * -.30 * 1 -.35 * 
 
 Sr * * * * .48 -.35 * ,51 -31 ***** ,31 -.35 1 .43 
 
 Ti * * * * * * * .30 ******** .43 1 
 
 V * * * * * * * .38 * * * .36 * * * -.42 * * 
 
 Zn -.32 ***** .32 ♦ * * .30 * * .33 * * * * 
 
 Zr * * * * * -.33 * .42 ******* -.34 * * 
 
 OTHER SEAMOUNTS, <3,000 m 
 
 Al 1 * -0.39 * * -0.33 * * * * -0.30 * * * * 0.59 -0,47 * 
 
 Ba * 1 * 0,98 * * * -0,52 * 0,42 ,53 * * * * -,34 ,31 -0,36 
 
 Ca -,39 ♦ 1 .74 * * ♦ -.40 -0.33 * * * -0,46 * * -,46 ,63 -,40 
 
 Cd * .98 ,74 1 -0.37 -,99 0.54 * * * -.44 * * 0,49 -0,34 * * * 
 
 Co * * * -.37 1 * * * ** * * * .30 .67 -.35 * .60 
 
 Cr -.33 * * -.99 * 1 * .54 .31 * * * -.40 * * * * -.35 
 
 Cu * * * .54 * * 1 * * .40 * * * .44 * * * * 
 
 Fe * -.52 -.40 * * .54 * 1 * * -.30 ****** .39 
 
 K * * -.33 **.31**1 ******* -.30 * 
 
 Mg * .42 * * * * .40 * * 1 * * -.45 .34 * * -.37 * 
 
 Mn -.30 .53 * -.44 * * * -.30 * * 1 * .34 .38 ♦ * * * 
 
 Mo * * * * * * * * * * *1 .61 * .31 * * * 
 
 Na * * -.46 * * -.40 * * * -.45 .34 .61 1 ***** 
 
 Ni * * * .49 .30 * .44 * * .34 .38 * * 1 * * * * 
 
 Pb * * * -.34 .67 ***** * 0.31 * * 1 * * .36 
 
 Si 59 -.34 -.46 * -.35 **********1 -.55 * 
 
 Sr -.47 .31 .63 * * * * * -.30 -.37 ***** -.55 1 * 
 
 Ti * -.36 -.40 * .60 -.35 * .39 ****** .36 * * 1 
 
 V 46 -.50 -.53 * * * .34 .42 .32 ******* * .30 
 
 Zn * * * .30 * * .40 * * * * * -.45 .48 * * * * 
 
 Zr 52 ****** .30 ********** 
 
 * No significant correlation found. Coefficients <-0.3 or >0.3 are considered significant. 
 
 Zn 
 
 
 
 
 * 
 
 * 
 
 0.68 
 
 * 
 
 0.57 
 
 -.38 
 
 * 
 
 * 
 
 ■k 
 
 * 
 
 * 
 
 •k 
 
 * 
 
 * 
 
 .42 
 
 * 
 
 * 
 
 -41 
 
 * 
 
 * 
 
 -,70 
 
 * 
 
 * 
 
 .67 
 
 0.46 
 
 * 
 
 * 
 
 * 
 
 -.42 
 
 -.42 
 
 * 
 
 ,43 
 
 ,39 
 
 -.52 
 
 * 
 
 * 
 
 .38 
 
 ,69 
 
 * 
 
 * 
 
 ,64 
 
 * 
 
 -.31 
 
 * 
 
 -.38 
 
 * 
 
 * 
 
 .58 
 
 * 
 
 * 
 
 -.36 
 
 -.30 
 
 -,34- 
 
 .59 
 
 1 
 
 ,31 
 
 * 
 
 .31 
 
 1 
 
 -.59 
 
 * 
 
 -.59 
 
 1 
 
 * -0.32 
 
 .32 
 
 0.38 
 
 .36 
 
 -.42 
 
 -0.33 
 
 * 
 
 .42 
 
 .30 
 
 .33 
 
 -.34 
 
 0.46 
 
 * 
 
 -.50 
 
 * 
 
 -.53 
 
 * 
 
 * 
 
 0.30 
 
 * 
 
 * 
 
 * 
 
 * 
 
 .34 
 
 .40 
 
 .42 
 
 * 
 
 .32 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 * 
 
 -.45 
 
 * 
 
 .48 
 
 0.52 
 
 .30 
 
 .30 
 
 Table 20 gives the elemental variation by sampling site for 
 the nodule in figure 61 . Figures 62 through 65 show spatial 
 distribution with respect to discrete sample locations on the 
 same nodule for the elements Cu and Ni, Co and Zn, Fe and 
 Pb, and Ba and Ce. Analysis of the sample sites was 
 performed by neutron activitation analysis and atomic 
 absorption spectrophotometry using small samples from 
 each site. 
 
 Figures 62 through 65 show that concentrations of Cu vary 
 directly with Ni and Zn and inversely with Ce, Fe, and Pb. 
 
 Barium does not appear to snow any relationship and could 
 be considered as associated with the accessory mineral 
 phase. These plots show the tendency of Cu, Ni, Zn, and 
 possibly Co in this nodule section to be associated with the 
 Mn phase and Ce and Pb to be associated with the Fe phase. 
 Although not shown, Mn varies similarly with the Cu and Ni 
 scans (see table 20). Figure 61 also shows the amount of 
 layering that takes place during nodule growth and the 
 differences in light and dark areas. 
 
55 
 
 ♦*•*!%►, 
 
 f^1*sr. 
 
 Scale, cm 
 
 Figure 61. — Unpolished cross section of nodule DH 9-9 (location 21°45' N., 113°10'W, 3,500-m water 
 depth). Numbered circles indicate locations of 24 discrete sampling sites for analysis. 
 
 Table 20. — Nodule cross section sample locations and analysis, figure 61 
 
 Sample Weight-percent 
 
 location Ba ^^ ^u Fe Mn 
 
 1 0.251 0.05 0.45 7.8 23.5 
 
 2 212 .02 .61 4.6 27.5 
 
 3 232 .03 .55 5.3 25.5 
 
 4 285 .06 .51 7.4 25.0 
 
 5 335 .06 .56 7.7 24.5 
 
 6 445 .04 .67 4.5 28.5 
 
 7 504 .03 .70 3.4 29.5 
 
 Sand 17 637 .13 .51 9.6 24.0 
 
 9 ND ND .53 ND 25.0 
 
 10 and 15 774 .18 .53 7.7 27.5 
 
 11 and 12 ND .16 .66 9.6 26.5 
 
 13and14 1.270 .10 .67 5.6 28.5 
 
 16 583 .14 .50 12.1 21.5 
 
 18 ND .10 .58 6.4 26.0 
 
 19 511 .05 .73 4.8 27.5 
 
 20 317 .04 .74 5.3 27.5 
 
 21 303 .04 .65 5.9 26.5 
 
 22 282 .06 .63 6.1 26.0 
 
 23 292 .04 .49 5.8 26.5 
 
 24 265 .04 .40 6.2 26.5 
 
 ND Not detected. ' Insoluble in HCI. 
 
 Ni 
 
 Pb Zn 
 
 Parts per million 
 
 Ce 
 
 Cr Cs Eu 
 
 Hf 
 
 La 
 
 Lu Sc Sm Ta Tb 
 
 Th Yb ^'■P'^' 
 
 0.85 
 
 1.00 
 
 .92 
 
 .82 
 
 .80 
 
 .80 
 .76 
 .74 
 .78 
 .98 
 
 .93 
 1.09 
 .60 
 .64 
 .92 
 
 1.04 
 .94 
 .96 
 .80 
 .80 
 
 0.04 0.31 
 .02 .34 
 
 .02 
 .03 
 .02 
 
 .02 
 .01 
 .03 
 .04 
 .02 
 
 .03 
 .02 
 .02 
 .02 
 .02 
 
 .02 
 ,02 
 .04 
 .02 
 .02 
 
 .30 
 .27 
 .25 
 
 .36 
 .43 
 .18 
 .18 
 .18 
 
 .20 
 .21 
 .15 
 .16 
 .30 
 
 .33 
 .36 
 .33 
 .34 
 .34 
 
 203 
 115 
 146 
 199 
 
 215 
 
 126 
 86.8 
 252 
 
 ND 
 215 
 
 ND 
 216 
 185 
 190 
 109 
 
 144 
 130 
 196 
 161 
 170 
 
 29.3 
 19.9 
 21.3 
 22.2 
 19.7 
 
 16.9 
 22.3 
 30.1 
 ND 
 32.5 
 
 ND 
 14.9 
 33.8 
 29.3 
 20.9 
 
 24.9 
 18.5 
 22.2 
 24.1 
 22.9 
 
 24.5 
 30.1 
 29.5 
 293 
 31.8 
 
 40,8 
 15.1 
 25.8 
 ND 
 23.7 
 
 20.2 
 21.4 
 22.0 
 32.6 
 30.3 
 
 35.0 
 30.1 
 24,5 
 26,4 
 24,2 
 
 7,1 
 5,0 
 5,6 
 7,1 
 6,6 
 
 5,2 
 4,6 
 4,4 
 ND 
 4,4 
 
 5,6 
 3,8 
 3,8 
 3,8 
 
 4,5 
 
 4,5 
 5,5 
 6,1 
 5,9 
 6,1 
 
 4,2 147 2,8 
 
 2,8 87,4 1.8 
 
 ND 96.1 1.9 
 
 ND 132 
 
 ND 136 
 
 2.7 
 2.7 
 
 2.1 
 1.8 
 2.2 
 
 2.9 104 
 
 3.0 111 
 
 7.3 143 
 
 ND ND ND 
 
 2.9 115 1.7 
 
 9.2 ND ND 
 
 ND 121 1.6 
 
 6.9 111 2.0 
 
 2.8 104 1.6 
 
 ND 105 1.9 
 
 4.8 101 1.9 
 
 2.7 112 2.3 
 
 ND 126 2,6 
 
 3.7 117 2,5 
 
 3.8 114 2,4 
 
 4,5 38,7 
 
 3,3 20,6 
 
 3.1 23.3 
 
 3.9 29.5 
 
 4.5 28.2 
 
 2.1 24.3 
 
 2.6 22.0 
 7.0 25.2 
 ND ND 
 5.8 20.2 
 
 7.3 ND 
 5.0 22.3 
 
 9.7 21.5 
 
 5.2 18.6 
 4.5 22.9 
 
 5.2 21.5 
 
 5.0 27.3 
 
 5.4 33.5 
 
 5.1 28.3 
 
 5.5 27.8 
 
 ND 5.2 
 
 1.1 3.7 
 1.6 4.1 
 
 2.2 5.0 
 
 1.4 4.6 
 
 .6 
 1.2 
 
 3.7 
 
 3.3 
 
 .8 3.4 
 
 ND ND 
 
 3.1 2.0 
 
 2.5 
 1.2 
 3.8 
 1.1 
 ND 
 
 .6 
 1.4 
 ND 
 1.4 
 
 .9 
 
 1.0 
 1.3 
 2.4 
 2.3 
 3.1 
 
 2.6 
 3.4 
 3.7 
 3.7 
 4.1 
 
 24.8 
 10.0 
 13.2 
 20.7 
 27.0 
 
 10.4 
 7.1 
 
 29.5 
 ND 
 
 38.1 
 
 39.1 
 16.9 
 34.8 
 22.3 
 11.9 
 
 14.5 
 16.3 
 19.5 
 15.3 
 19.1 
 
 18.8 16.0 
 
 12.0 17.7 
 
 13.4 12.7 
 
 18.6 8.4 
 
 18.3 14.2 
 
 13.2 
 11.2 
 
 7.8 
 7.8 
 
 14.7 13.0 
 
 ND 11.7 
 
 13.7 8.0 
 
 ND 15.0 
 
 11.8 10.4 
 14.2 22.1 
 
 10.9 12.3 
 13.6 8.0 
 
 13.2 15.4 
 
 15.9 10.0 
 
 18.0 13.5 
 
 18.5 8.7 
 
 16.5 14.4 
 
56 
 
 1.3 
 1.2 
 1.1 
 1.0 
 
 a. 
 
 -1 .8- 
 
 UJ 
 
 I .' 
 
 .6 
 .5 
 
 - 
 
 I I 
 
 1 1 
 
 - 
 
 A 
 
 - 
 
 ■A 
 
 / 
 
 \ IV 
 
 " 
 
 ^"Vy 
 
 \ A / ''"^ 
 
 - ^ 
 
 / 
 
 - / 
 
 Nickel 
 
 
 
 Copper 
 
 1 1 
 
 1 1 
 
 1.3 
 1.2 
 1.1 
 1.0 
 
 .8 of 
 
 .7 S 
 
 u 
 .6 
 
 .5 
 
 .4 
 
 10 15 
 
 SAMPLE LOCATION 
 
 20 
 
 25 
 
 Figure 62. — Spatial distribution off mcicei and 
 copper concentrations witli respect to discrete 
 sample locations on nodule cross section DH 9-9, 
 figure 61 . 
 
 11.0 
 
 9.0 
 
 7.0 
 
 3.0 
 
 - 
 
 1 
 
 
 1 
 
 
 1 
 
 
 
 1 
 
 
 y 
 
 
 
 
 
 r 
 
 
 
 
 
 : 
 
 
 
 
 
 
 \ 
 
 
 
 - 
 
 ■i 
 
 
 \ 
 
 
 ■*'' 
 
 J 
 
 ^'^>, 
 
 
 / 1 
 
 V,- 
 
 
 kv \ 
 
 * 
 
 V 
 
 ' / » 
 
 V- 
 
 -A 
 
 /\ 
 
 
 '- 
 
 \ 
 
 - 
 
 \ 
 
 \ 
 
 ■i / 
 
 
 V 
 
 
 \^ 
 
 / 
 
 
 - 
 
 
 
 1 Iron 
 / Lead 
 
 
 
 
 \ 
 
 VJ 
 
 
 
 1 
 
 \ 
 
 ■ 1 
 
 
 1 
 
 
 
 1 
 
 
 5 10 15 20 
 
 SAMPLE LOCATION 
 
 0.06 
 
 OS 
 
 .04 B 
 
 a 
 
 d 
 
 2 
 
 .03 -* 
 
 .02 t 
 
 Figure 64. — Spatial distribution of iron and lead 
 concentrations with respect to discrete sample 
 locations on nodule cross section DH 9-9, figure 
 61. 
 
 0.20 
 
 0.6 
 
 10 15 
 
 SAMPLE LOCATION 
 
 Figure 63. — Spatial distribution off cobalt and 
 zinc concentrations with respect to discrete 
 sample locations on nodule cross section DH 9<9, 
 ffigure 61 . 
 
 1.6 
 
 5 1.2 
 
 10 15 
 
 SAMPLE LOCATION 
 
 280 
 
 240 
 
 200 
 
 - 120 
 
 Figure 65. — Spatial distribution of barium and 
 cerium concentrations with respect to discrete 
 sample locations on nodule cross section DH 9-9, 
 figure 61. 
 
57 
 
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59 
 
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60 
 
 APPENDIX.— GLOSSARY OF MINERALOGICAL TERMS 
 
 Accrete. — The increase in size of an inorganic material by 
 the external addition of fresh particles, as by adhesion. 
 
 Acicular. — A crystal that is needlelike in form. 
 
 Amorphous. — A mineral that lacks crystalline structure, or 
 whose internal arrangement is so irregular that there is no 
 characteristic external form. 
 
 Angstrom (A). — A unit of length, used to express the length 
 of light waves, equal to 10-^ micrometer or 10° centimeter. 
 
 Antiferromagnetic. — A type of magnetic order in which the 
 moments of neighboring magnetic ions are alined antipara- 
 llel, so that there is no macroscopic spontaneous magnetiza- 
 tion. 
 
 Antithetic. — Concentration of elements in rocks or minerals 
 that vary inversely from one to the other. 
 
 Authigenic. — Rock constituents and minerals formed or 
 generated in place, not having been transported but derived 
 locally on the spot where they are now found. 
 
 6af/7ymefr/c.— Concerning the depth and topography of 
 the ocean floor. 
 
 Benthic. — Pertaining to the ocean bottom, including 
 marine life found there. 
 
 Botryoidal. — Having the form of a bunch of grapes. 
 
 Calcareous. — A material that contains a substantial 
 amount of calcium carbonate. 
 
 Cell parameters. — The length of axes in the unit cell, given 
 in angstroms. 
 
 elastics. — Rocks or sediments composed principally of 
 broken fragments that are derived from preexisting rocks or 
 minerals and that have been transported individually for 
 some distance from their places of origin. 
 
 Colloidal. — Fine-grained matter in suspension in seawater 
 that does not occur in crystalline form. Smaller than clay 
 particles. 
 
 Cryptocrystalline. — Crystalline substances of such fine- 
 grained aggregates that their crystalline nature cannot be 
 determined by an optical microscope, but can be determined 
 by X-ray diffraction. 
 
 Crystal lattice. — The three-dimensional, regularly repeat- 
 ing atomic arrangement of a crystal, each point of which has 
 identical surroundings. The lattice is built by the regular, 
 parallel translation in space of the unit cell. 
 
 Detrital. — Loose rocks or minerals that are worn off or 
 removed by mechanical means, as by disintegration or 
 abrasion, later forming other rocks, minerals, or sediments. 
 
 Diagenesis. — The recombination or rearrangement of a 
 mineral resulting in a new mineral. 
 
 d-spacing. — In refraction of X-rays by a crystal, the 
 distance or separation between the successive and identical 
 parallel planes in the crystal lattice. 
 
 Epitaxial. — An orientation of a crystal with that of the 
 crystalline substrate on which it grew. 
 
 Euhedral. — A crystalline solid with well-formed faces. 
 
 Ferrimagnetic. — A type of magnetic order, magnetic ions 
 at different crystal sites are opposed. However, there is a net 
 magnetization because of inequality in the number or 
 magnitude of atomic magnetic moments at the two sites. 
 
 Hexagonal. — One of the six crystal systems, having four 
 crystallographic axes, three of which are of equal length, and 
 
 are horizontal and intersect at angles of 1 20°. The fourth axis 
 (vertical) is of different length and perpendicular to the plane 
 of the other three. 
 
 Interstices. — Openings or spacings between objects. 
 
 Isometric. — One of the six crystal systems, having three 
 mutually perpendicular axes of equal lengths. 
 
 Isostructural. — Minerals related to each other by analo- 
 gous structures, generally having a common anion, and 
 displaying extensive ionic substitution. 
 
 Isotropic. — A crystal whose physical properties do not vary 
 according to crystallographic direction. Crystals that belong 
 to the isometric system. 
 
 Mammillary. — An aggregate of crystals taking the form of 
 rounded masses. 
 
 Metastable. — A phase that is stable with respect to small 
 disturbances but that is capable of reaction with evolution of 
 energy if sufficiently disturbed. 
 
 Monoclinic. — One of the six crystal systems, having three 
 unequal axes, two of which are inclined to each other at an 
 oblique angle and the third perpendicular to the plane of the 
 other two. 
 
 Octahedra. — An atomic structure or arrangement in which 
 an ion is surrounded by six ions of opposite charge, whose 
 centers form the corners of an octahedron, which is an 
 isometric crystal form of eight faces, and which are 
 equilateral triangles. 
 
 Orthorhombic. — One of the six crystal systems, having 
 three mutually perpendicular axes all of different lengths. 
 
 Polymorph. — A chemical substance that can crystallize in 
 more than one form, such as rhombic and monoclinic sulfur. 
 
 Psilomelane. — A general term for mixtures of manganese 
 minerals. 
 
 Rhombohedral. — A crystal form that is a parallelepiped 
 whose six identical faces are rhombs; that is, oblique, 
 equilateral parallelograms. Characteristic of the hexagonal 
 system. 
 
 Siliceous. — An abundance of free silica. 
 
 Solid solution. — A single crystalline phase that may vary in 
 composition within finite limits without the appearance of an 
 additional phase. 
 
 Space group. — In a crystal s*r;jcture, one of 230 different 
 ways of arranging atoms in a homogeneous array. 
 
 Supergene. — A mineral deposit or enrichment formed by 
 descending solutions. 
 
 Tetragonal. — One of the six crystal systems, having three 
 mutually perpendicular axes, two of which (the horizontal 
 axes) are of equal length, but the vertical axis is shorter or 
 longer than the other two. 
 
 Triclinic. — One of the six crystal systems, having a onefold 
 axis of symmetry and three axes of unequal lengths that all 
 intersect at oblique angles. 
 
 Unit cell. — The fundamental parallelepiped that forms a 
 crystal lattice by regular repetition in space. 
 
 Zeolite. — Signifies a group of hydrous aluminosilicates that 
 are analogous in composition to the feldspars. They are 
 characterized by their easy and reversible loss of water of 
 hydration, and their swelling up on heating. 
 
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