14.GS: CIR273 c. 1 STATE OF ILLINOIS WILLIAM G. STRATTON, Governor DEPARTMENT OF REGISTRATION AND EDUCATION VERA M. BINKS, Director Heavy Mineral Ratios of Sangamon Weathering Profiles in Illinois John A. Brophy DIVISION OF THE ILLINOIS STATE GEOLOGICAL SURVEY JOHN C. FRYE, Chief URBANA CIRCULAR 273 1959 Digitized by the Internet Archive in 2012 with funding from University of Illinois Urbana-Champaign http://archive.org/details/heavymineralrati273brop HEAVY MINERAL RATIOS OF SANGAMON WEATHERING PROFILES IN ILLINOIS John A. Brophy ABSTRACT Heavy mineral ratios were studied to compare the degree of weathering attained in buried Sangamon profiles developed on Illinoian till with that in profiles developed on Illinoian outwash. Grain sizes were determined and heavy minerals were analyzed for 59 samples from four sections. Two of the sections were from pro- files developed on clayey till and two from profiles developed on outwash, one of the latter being dominantly sand and gravel, the other silt overlying sand, silt, and gravel. The sections sampled had similar topographic positions so that differences in soil-form- ing factors, other than texture of parent material, probably were not great. In terms of depletion of hornblende and garnet, the rela- tively coarse-grained, open-textured outwash proved to be con- siderably more weathered than the till. In the zone of greatest weathering about 90 percent of the hornblende had been removed from the outwash but only 60 percent had been removed from the till. About 70 percent of the garnet also had been weathered from the outwash, but the amount of garnet in the weathered till had not been noticeably reduced. In the till profiles the original illite and chlorite were al- tered almost completely to montmorillonite. INTRODUCTION Previous investigations (Goldich, 1938; Dryden and Dryden, 1946) have established that minerals differ considerably in their degree of stability in the zone of weathering. Ruhe (1956) used this fact in setting up "weathering ratios" - the ratio of number of grains of relatively stable minerals to number of grains of relatively unstable minerals. He found that such ratios were higher in the upper portions of profiles than in the parent material and that the difference was greater in older profiles than in younger ones. The objective of the present study was to determine the effect of variations in texture of parent material on degree of weathering as measured by weathering ratios. The relation of the weathering ratios to variations in clay mineralogy also was studied. The study is based on Sangamon weathering profiles on Illinoian drift. I am indebted to George W. White, head of the Department of Geology, University of Illinois, and H. B. Willman, of the Illinois State Geological Survey, for supervision of the study; to R. T. Odell, Department of Agronomy of the Uni- [1] 2 ILLINOIS STATE GEOLOGICAL SURVEY versity of Illinois, for discussion of pedological problems; and to Herbert D. Glass, Illinois State Geological Survey, for discussion of problems of clay mineralogy. PROFILE SELECTION To evaluate the influence of the texture of the parent material on the de- gree of weathering that had occurred in the Sangamon profiles, profiles were chosen that exhibited great differences in parent material. Two of the profiles were developed in till and two were developed in outwash. As nearly as could be determined, there were only minor differences in the other factors of weathering, as noted below. Climate .- Within the sampling area (fig. 1), the climate probably was reasonably uniform during the period of profile development. Topography . - All the profiles studied were developed on flat or nearly flat uplands. Time . - All four profiles were developed on Illinoian drift after ice with- drawal and prior to burial by Wisconsin age loess. Biota. - There is little direct evidence, but it is assumed that if climate and topography were similar, differences in biota would not have been great. FIELD STUDY The four profiles were described (see appendix) and sampled vertically according to zones that were recognizable in the field (table 1 and fig. 2). Table 1 . - Zonation of Buried Profiles of Weathering (Modified from Leighton and MacClintock, 1930) Zone I. II. III. IV. V. Description Former surface zone, less clayey than zone II. Generally shows mixed-zone contact with overlying loess. Characterized by clay enrichment and often by structural development; niinoion sections pebbles, less common than in zone III, are dominantly dense, fine- grained silicates. Oxidized and leached of carbonates, Oxidized. Apparently unaltered. F- Flamingo (till) E- Effinghom (till) B- Breeds (outwash) C- Country Club (outwosh) Fig. 1. - Location of sections studied. HEAVY MINERAL RATIOS OF WEATHERING PROFILES 3 LABORATORY METHODS Standard pipette and screening methods were used to obtain grain-size distribution data for all samples (figs. 3-6 and appendix table A). The very fine sand (<. 125 mm >.062 mm ) was selected for heavy mineral studies because it contained the highest concentration and the greatest variety of heavy minerals. Part of the heavy-mineral yield of each sample was mounted in balsam, and a com- bined total of 300 grains of garnet (Ga), zircon (Zi), tourmaline (To), and horn- blende (Hb) was counted under a polarizing microscope. SELECTION OF WEATHERING RATIOS The high resistance to weathering of zircon and tourmaline and the low resistance of hornblende are well documented (Jackson and Sherman, 195 3), indicating that the ratio of zircon-plus-tourmaline to hornblende could be an effective index of weathering. The literature is not in agreement, however, on the resistance of garnet, so it was compared with high-resistance minerals by using the ratio of zircon-plus-tourmaline to garnet, and with low-resistance min- erals by using the ratio of garnet to hornblende. Weathering ratios for each sample and grain counts from which they were calculated are listed in table B of the appendix. VERTICAL VARIATIONS IN WEATHERING RATIOS Fe«tO Top of Songomon 20 30 35 40L Figures 7 through 10 show curves produc FLAMINGO COUNTRY CLUB Mi_x£d_49ne Peorian Loess Farmdole Loess Zone 1 Zone D Zone Iff ZoneV EFFINGHAM Trons i-n Peorian Loess Zone I Zone H ZQne_H Zone N Zone V BREEDS Peorian Loess Mjxed zone Zone I Zone II Covered Trans' I-H Peorian Loess Farmdole _Lpess_ Mixed - zone Zone n Zonem ZoneS to ZoneY Fig. 2. - Columnar sections correlated on top of the Sangamon weathered zone. ed by plotting weathering ratios versus depth. The general pat- tern of these curves is random variation upward through zones V, IV, and III, indicating little or no weathering loss of horn- blende or garnet in these zones. Above zone III, however, marked changes are evident. In the Fla- mingo and Effingham till profiles, the ratios of zircon-plus-tourma- line to hornblende, and of garnet to hornblende, show increases, but the zircon-plus-tourmaline to garnet ratio continues its ran- dom variation. In the Breeds and Country Club outwash profiles, all three ratios increase in zones II and I. COMPARISON OF DEGREE OF WEATHERING In figures 11 and 12 the weathering ratio curves have been mathematically reduced to a com- mon base for direct comparison. ILLINOIS STATE GEOLOGICAL SURVEY PERCENT Depth ft Zone Sample 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 _i i i i i I i i i i i i ' ' i i i ■ ' Fig. 3. - Grain size profile of Flamingo section. Depth ft Zone Sample PERCENT 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 _i i i i i i i i i i i i i i i i i i 1_ 2- 4 6- 8- 10- 12- 14- 16- 18- 20 22 Peorian Loess E - 17 vvvvvvuyvvvvvvvvvvvvi; ; //////////////// /////// / /;/;,•/;/;/;;//////;// /r~ E- i < v.- Clay Silt Sand Gravel Fig. 4. - Grain size profile of Effingham section. HEAVY MINERAL RATIOS OF WEATHERING PROFILES 5 PERCENT Depth ft Zone Somple 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 -I 1 1 1 1 1 1 1 1 _L I I I J I III! Fig. 5. - Grain size profile of Breeds section. Depth ft PERCENT Zone Somple 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 .iiiii i i i i i i i i i i i i i_ Fig. 6. - Grain size profile of Country Club section. ILLINOIS STATE GEOLOGICAL SURVEY 10 12 14 16 18 20 22 24 26 28- 30 32 34 36 5 w • OJ o o E ,o o Mixed m I4< E7 5< 6< Weathering Ratios .2 .4 .6 .8 1.0 • x "I r— ■ • xo ■ • X Clay % 10 20 30 40 |%<; >xcloy| % ?to2^i clay 12 3 45 Clay Mineralogy = (X-ray data) '»_ u. 7 o o >- 9 g io UJ CO M t 12 UJ ° 13 14 15 16 17 "i 1 r A-_ ~~ ~~ Sections O o Flomingo D □ Effingham A — -a Breeds X X Country Club ."5* Wrl = Averoge weathering ratio for lowermost 3 somples (from horizon Y or n?-Y) Wr2 - Weathering ratio for each higher sample Fig. 11. - Comparative curves for the ratio of zircon-plus-tourmaline to hornblende. Wr2 Wr I 3 D h Sections O — -o Flamingo □— ■D Effingham A— -A Breeds X -X Country Club Wrl = Average weathering rotio for lowermost 3 somples (from horizon V or BT-Y ) Wr2 = Weathering rotio for each higher somple Feet i - □? o D \ S m „ ^n _J 2 " °\D u_ is! i ■ «/ ° 2 4 o r \ ° - \ Q T - ^ A * dl A, " 1 5 t 6 < w - J * 1 u. ' - 04; , ° R _ 4 \ ' 0. Vp yj. O \ -' 1 »- 9 5 g io UJ a' \ I 1 1 •- .- 1 1 1 o- 12 UJ " A 1 o .-. 1 1 13 " 14 " 15 r ? / 16 • ' 17 A^ .--«■: Fig. 12A. - Comparative curves for the ratio of garnet to hornblende. Fig. 12B. - Comparative curves for the ratio of zircon-plus-tourmaline to garnet. HEAVY MINERAL RATIOS OF WEATHERING PROFILES 9 The difference in degree of weathering between the till profiles and the outwash profiles is striking. Not only has hornblende undergone considerably more depletion by weathering in the outwash profiles (fig. 11), but garnet, which shows no loss by weathering in the till profiles, has been partially weathered out of the upper zones of both outwash profiles (fig. 12). Quantitatively, there has been a loss of about 90 percent of hornblende in zone II of the outwash profiles compared to a loss of about 60 percent in the till profiles. Loss of garnet is about 70 percent in the outwash compared to little or no loss in the till. The depth to which carbonates are leached provides additional evidence of the greater degree of weathering that has occurred in the outwash profiles. Depth of leaching averages about 14 feet in the outwash but only about 7 feet in the till. DISCUSSION The observed differences in degree of weathering are considered to be re- lated primarily to differences in texture of the parent material. The relatively coarse-grained outwash sediments certainly would have been the more permeable to weathering solutions, thus facilitating decomposition and removal of the solu- ble products. In the relatively fine-grained till profiles slow percolation rates would have allowed a higher percentage of the precipitation falling upon them to run off or to be removed by plant transpiration. A number of pedologists (cited by Jenny, 1941), following other lines of evidence, have observed the same relation- ship of parent-material textures to soil development. This study also indicated that the resistance of garnet falls between that of hornblende and the zircon-tourmaline group, under the weathering conditions that prevailed. More research is needed to determine why garnet is not depleted in the till profiles.which have lost 60 percent of their hornblende, and yet is strongly depleted in the outwash profiles, which have lost only 30 percent more hornblende. From this study and those of Ruhe (1956), weathering ratios appear to be a promising method of evaluating profile maturity, especially in buried profiles where standard pedologic tests of maturity may not work. Clay Mineralogy Zone II of the profiles is considerably enriched in clay (figs. 7-10). Ratios of the percentage of minus ^-micron clay to \- to 2-micron clay show that most of the clay added to this zone is in the minus ^--micron fraction. To determine the relationship of this clay increase to the increase in the heavy mineral ratios, clay mineral analyses were made of both till sections by Herbert D. Glass, using a General Electric XRD 3 recording spectrometer. The results of the analyses are graphed in figures 7 and 8 and are discussed below. Clay minerals of zone V are predominantly illite and chlorite. Chlorite begins to show alteration in the oxidized calcareous till (zone IV) and becomes progressively more altered upward in the profile, changing first to mixed vermiculite- chlorite, then to vermiculite, and finally, in zones II and I, to montmorillonite. The first appearance of substantial illite alteration occurs somewhat higher in the profile than that of chlorite, although illite probably is slightly altered at lower levels. Illite goes through a mixed-lattice illite-montmorillonite stage, with montmorillonite becoming more dominant upward in the profile until, in zones II and I, alteration is nearly complete. Montmorillonite, therefore.is the clay mineral producing the increased percentage of minus ^--micron clay in zone II. 10 ILLINOIS STATE GEOLOGICAL SURVEY The close correspondence between the base of the montmorillonite zone and the base of the zone of hornblende depletion (essentially the base of zone II) sug- gests that the montmorillonite may have acted as an acid clay in the breakdown of the hornblende. Graham (1941) showed by experiments that montmorillonite as an acid clay can be highly effective in weathering of minerals. SUMMARY Weathering ratio studies show that there can be considerable differences in degree of weathering between Sangamon profiles developed in till and those devel- oped in outwash. Because other factors of soil formation were about the same for both till and outwash profiles, it is concluded that the differences in degree of weathering were caused primarily by differences in texture of parent material. In the profiles studied, the base of the zone of clay enrichment coincides with the base of the montmorillonitic zone and the base of the zone of maximum depletion of hornblende and garnet. Weathering ratios seem to hold promise for evaluating maturity of weathering profiles. REFERENCES Dryden, Lincoln, and Dry den, Clarissa, 1946, Comparative rates of weathering of some common heavy minerals: Jour. Sedimentary Petrology, v. 16, no. 3, p. 91-96. Graham, E. R., 1941, Acid clay - an agent in chemical weathering: Jour. Geology, v. 49, no. 4, p. 392-401. Goldich, S. S., 1938, A study in rock-weathering: Jour. Geology, v. 46, no. 1, p. 17-58. Jackson, M. L., and Sherman, G. D., 1953, Chemical weathering of minerals in soils: Advances in Agronomy, v. 5, p. 219-318, Academic Press, New York, N. Y. Jenny, H., 1941, Factors of soil formation: McGraw-Hill Book Co., New York, N. Y. Leighton, M. M., and MacClintock, Paul, 1930, Weathered zones of the drift sheets of Illinois: Jour. Geology, v. 38, no. 1, p. 28-53. Ruhe, R. V., 1956, Geomorphic surfaces and the nature of soils: Soil Science, v. 82, no. 6, p. 441-455. Shepard, F. P., 1954, Nomenclature based on sand- silt-clay ratios: Jour. Sedi- mentary Petrology, v. 24, no. 3, p. 151-158. Soil Survey Staff, 1951, Soil Survey Manual: U. S. Dept. of Agr. Handbook 18. HEAVY MINERAL RATIOS OF WEATHERING PROFILES 11 APPENDIX DESCRIPTION OF PROFILES In the following descriptions, color determinations are from the Munsell Soil Color Charts. Textural nomenclature is that devised by Shepard (1954). Clay size is taken as < 2 microns. Where pebbles or coarser stones are important con- stituents, the words "pebbly" or "cobbly" are added. Where these coarser con- stituents are dominant, Shepard's system is not used.Pedologic textural nomen- clature (in parentheses) and soil structure nomenclature are as recommended by the Soil Survey Staff (1951). The term "gravelly" in pedologic textural nomenclature is strictly a size term. Flamingo Section Location: Abandoned highwall of Fairview Collieries Flamingo Mine, NW{ SW^ NW| sec. 31, T. 8N., R. 3E., Fulton County, Illinois (Canton quad- rangle) . Sangamon topography: Broad, nearly flat upland divide, probably sloping slightly to the northwest. Elevation of Sangamon surface: 677'± (estimated from topographic map). Exposure faces north, moisture content normal. Description compiled from field and laboratory data: Unit Aggregate thickness thickness (ft. in.) (ft. in.) Peorian Loess Modern soil at top, noncalcareous to 7 feet, calcareous from 7 to 10 feet 10 10 Farmdale Loess Yellowish brown (10YR 5/4) clayey silt (silt loam), noncalcareous 2 6 12 6 Mixed zone Yellowish brown (10YR 5/4) clayey silt (silty clay loam), slightly more clayey than unit above, a few scattered pebbles, noncal- careous 1 13 6 Illinoian Till with Sangamon weathering profile Transition, zone I to zone II Dark grayish brown (10YR 4/2) clayey silt (silty clay loam), moderate fine sub- angular blocky structure, clay skins on peds, numerous large borings of crayfish type, a few small pebbles, noncalcareous... 9 14 3 Zone II Brown (10YR 4/3) clayey silt (silty clay loam), more clayey than unit above, moderate fine blocky structure at top to strong coarse blocky structure at base; shows prismatic tendency 12 ILLINOIS STATE GEOLOGICAL SURVEY , , . , . , , (ft. in.) (ft. in.) on dry face, clay skins prominent (color above is that of clay skins, ped interiors are brownish yellow [10YR 6/6]), a few small pebbles, noncalcareous 2 3 16 6 Transition, zone II to zone III Mottled 50 percent brownish yellow (10YR 6/6) and 50 percent light olive gray (5Y 6/2) sand-silt-clay (silty clay loam), very weak, very coarse blocky structure, texture more till-like than above, pebbles slightly more numerous and larger than above, noncal- careous 1 17 6 Zone III Mottled brownish yellow (10YR 6/6) and light olive gray (5Y 6/2) clayey silt (silty clay loam) to pebbly sand- silt-clay (gravelly loam), structureless, brownish yellow mottles increase downward from about 50 percent to about 90 percent; texture shows some effects of water sorting (some sandy lenses and some finer grained zones), pebbles larger and more numerous than above, noncalcareous 2 5 19 11 Zone IV Light yellowish brown (10YR 6/4) pebbly sandy silt (gravelly silt loam) to pebbly sand- silt- clay (heavier gravelly silt loam); strong brown (7.5YR 5/6) appears along joints at 6 feet and continues to base of zone IV; matrix gradually changes downward from light yellowish brown to light brownish gray (2.5Y 6/2) near the base; contains pebbles, cobbles and a few boulders, calcareous 9 8 29 7 Zone V Gray (5Y 5/1) pebbly sandy silt (gravelly silt loam) to pebbly sand- silt-clay (heavier gravelly silt loam), contact sharp with unit above, though oxidation continues down along joints; contains pebbles, a few cobbles and a few boulders, calcareous 6 35 7 Covered below. Effingham Section (first described by Leighton and MacClintock [1930]) Location: North wall of drainage ditch, center sec. 6, T.7N., R. 6 E., Effingham County, Illinois (Effingham quadrangle) . Sangamon topography: Very flat upland divide. Elevation of Sangamon surface: 577 '± (estimated from topographic map). Exposure faces south, moisture content normal. Description compiled from field and laboratory data: HEAVY MINERAL RATIOS OF WEATHERING PROFILES 13 Unit Aggregate thickness thickness (ft. in.) (ft. in.) Peorian Loess Modern planosolic soil at top, noncalcareous. . 3 5 3 5 Farmdale? Gray (10YR 6/1) sand-silt-clay (silt loam) with black streaks, may be part of Sangamon profile mixed with loess, noncal- careous 7 4 Illinoian Till with Sangamon weathering profile Zone I Gray (10YR 5.5/1) sand-silt-clay (loam), mottled 10 percent (at top) to 50 percent (at base) with yellowish brown (10YR 5/6 to 5/8), a few quartz and chert pebbles, noncalcareous 1 11 5 11 Zone II Dark gray (10YR 4/1) to gray (10YR 5/1) sand- silt-clay (loam to clay loam), yellowish brown (10YR 5/6) mottling at top increases downward until it becomes the predominant color at about 2\ feet below top, structure- less, clay decreases downward, pebbles (mostly chert) larger and more abundant than above but still not common, lower part grad- ually transitional to zone III, many crayfish- type borings, noncalcareous 5 1 11 Zone III Yellowish brown (10YR 5/8) pebbly silty sand (gravelly loam), mottled about 5 percent with light gray (10YR 6/1), texture more till-like, some thin sand and gravel beds in this part of profile, noncalcareous 10 12 Zone IV Light yellowish brown (10YR 6/4) pebbly silty sand to pebbly sandy silt (gravelly loam), very compact, coatings of gray (N 6/0) on vertical and horizontal fracture surfaces, calcareous 1 5 13 5 Zone V Gray (5Y 5/1) pebbly sandy silt (gravelly loam), extremely compact, gray (N 5/0) coatings on fracture surfaces, slightly oxidized to grayish brown (2.5Y 5/2) along joints, calcareous 7 6 20 11 Covered below. 14 ILLINOIS STATE GEOLOGICAL SURVEY Country Club Section Location: Abandoned highwall of Truax-Traer Fiatt Mine 2, now on property of Wee-ma-tuk Country Club, SE^ SW} NW| sec. 2, T. 6 N., R. 3 E., Fulton County, Illinois (Canton quadrangle). Sangamon topography: Essentially flat upland divide, may have had slight west- ward slope. Elevation of Sangamon surface: 660'± (estimated from topographic map). Exposure faces north, moisture content normal. Description compiled from field and laboratory data: TT . Unit Aggregate thickness thickness (ft. in.) (ft. in.) Peorian Loess Modern soil at top, noncalcareous 8 8 8 8 Farmdale Loess Dark grayish brown (10YR 4/2) clayey silt (silt loam), contains scattered flakes of carbonaceous matter, noncalcareous 2 10 8 Mixed Zone Brown (10YR 4/3) clayey silt (silt loam), probably a mixture of Farmdale Loess and zone I material of Sangamon profiles, non- calcareous 12 11 10 Illinoian outwash with Sangamon weathering profile Transition, zone I to zone II Yellowish brown (10YR 5/4) to dark yellowish brown (10YR 3/4) clayey silt (silty clay loam), very weak medium subangular blocky structure, clay skins on peds, some iron oxide pellets ("buckshot"), noncalcareous.. 11 12 9 Zone II Dark brown (10YR 4/3) silty clay (clay), mod- erate medium subangular blocky structure, clay skins on peds, noncalcareous 19 14 6 Zone II and Transition, zone II to zone III Mottled light brownish gray (10YR 6/2), yel- lowish brown (10YR 5/6), and black (N 2/0) silty clay (clay), changing downward to pebbly sand- silt-clay (gravelly clay loam), weak, medium to coarse blocky structure, contains resistant pebbles up to 2 inches in diameter, noncalcareous 2 6 17 Zone III Strong brown (7.5YR 5/6) cobbly, pebbly sand- silt-clay (cobbly, gravelly clay loam to sandy clay loam), structureless, some indications of bedding, numerous large borings of crayfish type extend about half- way down, noncalcareous. This and the HEAVY MINERAL RATIOS OF WEATHERING PROFILES 15 (ft. in.) (ft. in.) units above may be the weathered remains of a water-laid till or a very poorly sorted outwash deposit 5 6 22 6 Units below are definitely outwash. Interbedded sand and silt, noncalcareous, (not sampled) 2 24 6 Multicolored but predominantly strong brown (7 . 5YR 5/8) pebbly clayey sand (gravelly sandy loam), noncalcareous 3 6 28 Zone IV to V Light brown (10YR 6/4) sand (loamy sand), clean, well sorted, calcareous 6 28 6 Interbedded sand and silt, calcareous, (not sampled) 4 4 32 10 Multicolored but predominantly light brown (10YR 6/3) sand (loamy sand), weak iron oxide cementing, calcareous 10 33 10 Interbedded sand, silt, and gravel, cal- careous (not sampled) 2 4 36 2 Multicolored, very poorly sorted water-laid sediment, predominantly a very coarse gravel, but containing all sizes from 2-foot boulders to clay, calcareous 6 42 2 Silt and sand, calcareous (not sampled) 15 43 7 Covered below. Breeds Section Location: Gravel pit, SE{ NEj NWi sec. 33, T. 7 N., R. 5 E., Fulton County, Illinois (Glasford quadrangle). Sangamon topography: Essentially flat upland divide. Elevation of Sangamon surface: 575'± (estimated from topographic map). Exposure faces south, extremely dry. Description compiled from field and laboratory data: Unit Aggregate thickness thickness (ft. in.) (ft. in.) Peorian Loess Modern soil at top, lower foot or so maybe Farm- date Loess (extreme dryness made differen- tiation uncertain), very pale brown (10YR 7/4) clayey silt (silt loam), noncalcareous 4 6 4 6 Mixed zone Light yellowish brown (10YR 6/4) clayey silt (silty clay loam), noncalcareous 10 5 6 16 ILLINOIS STATE GEOLOGICAL SURVEY (ft. in.) (ft. in. Illinoian outwash with Sangamon profile of weathering Zone II Dark yellowish brown (10YR 4/4) clayey silt (silty clay loam), mottled with strong brown (7.5YR 5/8); strong medium prismatic struc- ture becoming coarse near base; large cray- fish-type borings, clay skins prominent, noncalcareous 2 6 8 Transition, zone II to zone III Very pale brown (10YR 7/3) clayey silt (silty clay loam), mottled with brownish yellow (10YR 6/6), moderate very coarse blocky structure, a few clay skins, noncalcareous.. 6 8 6 Zone III Same as unit above, but less clayey, struc- tureless, noncalcareous (not sampled) 13 9 9 Multicolored but predominantly brown (10YR 5/3) sand (loamy sand), noncalcareous 12 10 11 Very pale brown (10YR 7/3) clayey silt (silt loam), strong brown (7.5YR5/6) stain along joint faces, noncalcareous 9 11 8 Pale brown (10YR 6/3) pebbly silty sand (gravelly sandy loam), pebbles are scat- tered in sand matrix, noncalcareous 11 12 7 Multicolored but predominantly dark yellowish brown (10YR 4/4) poorly sorted deposit, pre- dominantly gravel and sand with some clay and a small amount of silt; a few large lime- stone or dolomite "ghost" pebbles, but ma- trix is noncalcareous 1 7 14 2 Reddish yellow (7.5YR 6/6) sand (loamy sand), contains a few silt layers, noncalcareous... 2 6 16 8 Silt, noncalcareous (not sampled) 2 16 10 Strong brown (7.5YR 5/6) sandy gravel, non- calcareous 3 17 1 Yellowish brown (10YR 5/4) sandy gravel (same bed as unit above, but calcareous) 19 18 10 Laminated silt and sand, calcareous (not sampled) 2 19 Multicolored sandy gravel, calcareous 4 3 23 3 Pebbly silty sand, calcareous (not sampled).... 5 23 8 Multicolored pebbly sand (gravelly sand), faintly oxidized, calcareous 1 6 25 2 Covered below. HEAVY MINERAL RATIOS OF WEATHERING PROFILES 17 en •z. o 1— 1 B uu CO ^— ^ +-> ll. x: o en •H •P-. Q) o =S \-\ H >- h-t X) co ( ) +-> u. c s d> n O U M CD •-) Q. < u C h- 1 •H 2 2 U) 0) U u PJ 3 > CT> • H 1 <-W . f— 1 < i— ( < a ^^ m < H. (unu 300 *>) Abjd ib^oi (mm qooO*>) Aejo auij Ajsa o} auij [unu Q000*) Aeio mnipaw (mm I00*) Aejo asjeoo (mm Z00'<290'>) His xeioi (mm 200*) }"[I S auij AjaA [uu" ?00"<0T0'>) ^Xis auT£ z CO If) O CM O CN —I TO CD nO nO ■— I o 00 o o O nO CO o CM CO CM co co co CO CO co CO on CO CM CM 00 •—I in CM CO CM co CM i— ! 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Ph PL, LL, LL, PU PU PL, P-, PL, PL, PU 4) 3 C •H -t-> c o o 1 ^_^ to 2 O en n H O s 8 u-. o 4-> c § (1) o H n 0) Q. 00 2 C 2 C ) u M fj 3 <. u n 5 i— ( t— ) o _< 3 CM CO co i— i CO CO CO oo ■— i O 00 CM 00 2 o <3- 00 CM •— 1 o oo o 00 oo o CO CM co CM 1—1 CM CM CM oo CM IT) CM 00 CM r- CM oo CM CM CM CM CO in iD ■>$- 00 r~ O ■St CO CM O O r- CO 00 00 O <* o 00 CM CM CO CM CM .—t 00 oo o 00 00 CM co •— i CO i— 1 00 o CM i-H CM CM co CM CO CM on 1—1 •— 1 •— i •— 1 <3- 00 oo o 1—1 18 ILLINOIS STATE GEOLOGICAL SURVEY (ujui 200*>) Aexo \v%oi (ujui Q000*>) Aexo 9Uij AJ9A 0TJ. 9UI£ (ujui g000'<100*>) Aexo tunipew (ujuj T00*<300*>) Aejo asjeoQ (ujui 300') q.XTS xe^-oi (ujuj 300*) }XT S au IJ AjaA (ujui QOO^OTO^) +IT S 9U Td cMo^t^vovot^ vo^oiDiOvo CM CM 00 r- co o 00 in 00 CM O 00 CM o i— i O CO vO i— 1 ■* O i— 1 o 00 CM CM CM CM CM CM 00 CM 00 CM 00 CM O O o o o o CM OO CM CM in O i-H co CM o <* 00 CM CM CM iT) 00 on 3 CO 00 CM CM CM CM CM CM CM CM CM 00 00 00 00 00 00 CO ■— i vO 00 in 00 O lX0 co CM CM CO oo 00 in 00 CM 00 CM CM O 00 00 o in CM xf ID in t> r- vO ^P in oo iO i—i ON vO •3- vO r- oo vf) co r~ iO vO in <¥ ■* t t <* oo co oo 00 00 "* t ■tf T ■3- CO CM 00 CM oo CM co CM in vO o 00 lT) oo o o O •—I co o CM t- vO 00 o r- vO t ^ ■* ^r •* 00 00 00 iT) vO ^O vO vO r- vO CM 00 ^o 1— I o CM ON o CO o in 00 o oo CO vO co co CO (ujuj oTo*) (ujuj oeO') § 1-XTS asjeoo S T^ ( ) l— i ■* it vO vO CM CM O "* 00 00 <* vO OM o 00 C3 o UJ o i-H o o O O «* o r> lT) • vO r~ O CM oo i— I CM O oo in t 00 00 vO r~ vO 00 oo a; 00 CM CM CM CM CM CM (ujuj 390*<29C*3>) pues \v\ol (ujui 390*) pues 9UTJ AJ9A (UJUI CZ\') pues auxj (ujui 0?2*<00Q # >) pues uiriipaw (ujui OOQ'<000'T>) pues asjeoo (ujui §w\) pues asjeoo Ajsa (ujui 29e*2<) X3Aejo) LU 0> CO 00 o in o oo ^1- 00 CM o CM iD lT) CM CO ao oo CM co CM -St co oo CO CO 00 1—1 ■—1 o ■—I ■—I o i-H i— l i— i o o oo M" CM r~ 1 CM Gp o o f— i oo CM i-H "Sf 00 O0 in 00 oo co t> oo ON CM ^O i-H in oo r- 00 in CO axduies 00 1— t o 00 O CO ■—I 00 00 CM 00 CM 1—1 00 CM co o 00 o ON 00 00 in 00 00 CO 1—1 00 CM CO CM ID 00 o "3- vO co ■—1 vO 1—1 in 00 iT) 1—1 CM o i-H vO 00 in r- co o 00 vO lD iT) iD iD vO r~ r~ r- o 00 Ov r~ r~ r- in o vO 00 00 1—1 00 00 ■—I ^O ON co o o o •—I vO in 00 vO co ■-o o t- o i-H o 1— t o o ON o ■—I CM CO iD CM co •—t o o 3 o 00 oo n 00 oo MO oo •—I oo -o o ON o r- 00 CM vO if) lT) o CM CM O lT) CM o lT) i-H vO o> o 1—1 o o o o -3- 00 .—I 1—1 oo ■—1 ■—I r~ r~ r- •—I ^o CM o 00 o vO oo o o in •—I O oo lT) 00 o ■■o o co i-H CO ON o 1—1 CM CM oo CM 00 CM CM ^t ■vt CM M- <—i ■* CM CM 1— 1 in 00 n oo oo oo ON i-H vO 1—1 00 i> »— i ■—I oo vO iT) c> c> i—4 iD o o i—4 o o o o 1—1 i-H ■—I CM •—I CM 1—1 00 00 CO vO 00 oo lT) if) c> CM o •-< 00 00 00 CM ON St 00 ON r-4 o i— 1 •—I o o o •—{ CM 1—1 o ^t CM CM 00 CM ^J" f- >o iT) <* CO CM 1—1 o C> 00 r- vO in M" 00 CM <—i UJ ai UJ UJ IXI UJ UJ w UJ UJ UJ UJ UJ UJ UJ UJ UJ T3 0) 3 C -P c HEAVY MINERAL RATIOS OF WEATHERING PROFILES 19 . ^. OOOOM-OOcMCMOvOOCOOO^nCM (uiui 300^) ^hoooooo o in t- ^r o in o cm abxo T e ^°I (N h in in o d d cm d d ^' oo n cm co co oo o •— i •— i t-H i-h (uiui 5000* > ) cm cm o o o oo -t cm vo oo h in in v ™ uu / in co co o o m- o o in .-h o ^h o AeTO 3Uii /_«. „., ,„' >n oo vo o oo o in o oo o cn-h^h AJ9A 0} 3UT£ h Ol Ol (N CM •-< -H ^ —I (uiui <5000*<100*>) cm cm cm cm m- in m- oo r- o o o vo fr,™ ,„r^~=,., O CM -H CM O CM O 00 O 00 00 CO vO Aeto uinipaw co t in oo co o—iooo ooo (uiui T00*<300">) t ^ oi ^o oo -tfcNvovoo oo r- -i v wu w~< / voo-^voo cm in co o m r~ o vo Abto ssjeoo ..... 00 00 ) oi r- ^ J5 ^f in r- ^h o o cm -n ^r }"[ TS ie T oj: oO'tcM^H oo cm o in oo o in in r- vo in in vo vo oo fuiui Z00*) o^Ovocnvo in vo o oo cm n in ^ * wu ,U Y ' o cm oo co r- in o o in oo , . vOOcM'tOOcMO^^HvOCMCM w x: (uiui 500*<0T0*>) r- t- ^ oo ^o in-nooin m-^hoo o "- 1 T TT S 3UI d r-i cm o o o ooot^io ^^ho $ xi (uiui 0T0"<0£0">) z o oo r- o r- oo ^ o o oo o r- \r 1TTS UITlTpaWi-H d OT 't CM O -^ ^ CM -H -n d -h cm xii ^"h CO CM CM CM 00 00-1 u W , oo o oo cm cm ^o in r- oo •** oo voinr- (mui 0C0*<390" > ) in ■* r- o cm h h m ^t co ^ co -i }tts asjBOQ a d d cm -h cm r^t^d^d m d h U4-— I^H-— lr-H.-H .-I .—I UJ ,pq- oo o (uiui 390*<39£*3>) inoin-a-in in r- o oo r- co o ,-h pues TEioi r- r- o ^ r- in t^ .-i oo vo o cm o —I OO^H^rcOOO^CMt- (uiui ?:90*) >n ^t oo h rt oo oo o in oo cm vo in pueS 8UTI Aja/\ . -J CM CM ") cooinoi^ co o >* o cm co *o o pues 9Ufj oi oi pi "f h cm vo in co r- ) t^^-i^ir-oj ini-^nM-^ votoo ai 9 pues umxpaw ^^h^h^h^ ^-cni^^o roooin in .-i ■— I vD t-H CM CMOinCOCM ^-lOCOvOvO vClrHO (uiui 00Q*<000*I>) ooinininoo fin^ojoo or~^ pues asjeon odooo indogovo cmcooo ) tr-co-ir- o pi eo co * ^hvo^i pues asjeoo Aa9A ddddo cMOcoodd r-^dr^ ^H f-H r-l in oo i-i oo (uiui 29C*3<) t °i ^ "i "*, XSAbjo d d d d t CO CM rH o . i— t •— i ■— i w— i i— i ajduies " ' ' • • a 00 03 0Q 03 00. t- n in t- ■-I ^H ^t CM co CM O CN 1 • • • in in O in oo CM ^H •tf M- vO •-t o 00 r- vO in ■tf CO ■-t 03 03 03 03 03 03 03 CQ 20 ILLINOIS STATE GEOLOGICAL SURVEY 3 C ■H +-> c o u 1 „ s -P CO x: 2 m C ) •rH p— 1 Q> H =S ! > UJ > 53 X! Ph -P o C 0) 2 o o tH KH (1) H o. i-i CO c ( ) •H u, > m ( > (i> u u n ►J en < •H u <+H H- 1 z I-H 3! I-H u LU ^ UJ PQ < (ujui 200 '>) Ae-[o ieq.01 (ujui Q000*>) Aejo suij; Aj8a 0} aui£ (uw Q000*<100'>) Aejo uinipsw (uiuj I00'<200'>) (ujuj 200*<290*>) j,Its -[£3,01 (mm 300*) }"[T S 9UIJ AJ9A (uiuj <500*<0T0*>) q,Xis auxj (muj oio*) (ujuj oeO"<290*>) J,fTS SSJBO0 ;™ 390'<39e*2>) pues ieo,oi (uiuj 290*) pues puij Ajsa (ujui ?2T<0Q2'>) pues auij (ujuj 0QZ*<00Q'>) pues uintpaw [uiuj 00Q*<000*T>) pues asjeoo ;ujuj ooo*i) pues ssjeoo Aj8A [UJUJ 29e*3<) X9ABJ0 aiduies CM ■3- o M0 •J CM 00 o CM o M0 M0 CO CO in in r- o in o 00 i-H CO CM M0 CO iD CO I— i CM CO CO CO CM CO o CO ON ■-H ON ON 00 CO 00 M0 p- M0 cM CM 00 O in o o CO M0 M0 CO CM oo r-H M0 CM CO CO co CO CM CM CO CM ON f-i CM i-H M0 M0 ^r o p» o M0 CM CO 00 .— 1 CM O o •—< M0 CM r-i ■-H M0 CO o 03 CM CO CO CM CO CM i-H CM *t ■* CO i-H •—< i— i CN 00 M0 CM M0 M0 CM CO i-H in CO ON CM in in O CN CO CO CO CO CO CM CM t M0 CO r—\ >-H CM O -JO mo P- CO ^3- O i-H CM •— 1 CO CO O in CM co M0 M0 r- CN p- MO M3 p- CO CO 00 CO CO CM r- CM i-H CM 00 CM i-H ON o i-H 03 ■tf o CM co CO o in CM in CO O ■-H CM O CO o o r- CO CM M0 t> mo o vD ^o in vO M0 M0 ON "* CM CM CM CM CM P- CM o in o 00 00 o r- co M0 in co r- in CM M0 o oo CO o If) o I-H o r-H co r~ o r- ^r o CO in CM r— 1 - 1 ^'■ 2 o CM r- mo CM oo CO O o o i-H O •-H M0 CO CO CO in CO M0 ON CO M0 H O UJ to § u o <^ CM CM r-H CO M0 00 CM OS 00 oo i-H o CO t-H CO in CM »-H r-H in in o CM CO ON CM o o CM On CO in --H & o r-H CM i— i oo t- oo CO ^O •* in ■^r CM CM CO CM > H M3 00 o o CO CO 00 CM in M0 t— 1 in CM O CO ON CO r- in 00 CO (7* R 00 CO r— 1 uD "Sf in i-H CO CM ■-H >* CM co co ON ■a- ON ON CO ro CO r-H oo CM o CM o CO i-H CM "St M0 ON ON o in M0 M0 in O ON CM CO ■* ■St CO in ^t CO CM CM •—< CM oo o 00 CM O CM C3N 00 o CM CO in o (N in o ON in M0 CM "«r lO -5f &4 <39 >?3 Loess F-14 Mixed 84 36 21 159 .53 .36 .68 F-13 Tr j"ii 84 39 17 160 « 53 « 35 - 67 F-12 II 75 45 22 158 .47 .42 .89 F-ll II 93 30 19 158 .59 .31 .53 F-10 II 103 46 17 134 .77 .47 .61 F-9 ii-ili 80 20 8 192 * 42 ,15 * 35 F-8 III 74 15 13 198 .37 .14 .38 F-7 III 71 25 8 196 .36 .17 .46 F-6 IV 53 14 9 224 .24 .10 .43 F-5 IV 45 17 18 203 .22 .17 .78 F-4 IV 51 17 15 217 .24 .15 .63 F-3 V 56 13 13 218 .26 .12 .46 F-2 V 43 25 12 220 .20 .17 .86 F-l V 50 23 9 218 .23 .15 .64 E-17 EFFINGHAM SECTION Peorian " Loess E-16 Silt 143 16 13 104 1.38 .28 .20 174 30 7 89 1.96 .42 .21 197 22 6 75 2.63 .37 .14 202 19 8 71 2.85 .38 .13 192 24 6 78 2.46 .38 .16 186 29 5 80 2.33 .43 .18 137 20 16 127 1.08 .28 .26 169 22 9 100 1.69 .31 .18 179 23 6 92 1.95 .32 .16 185 15 8 92 2.01 .25 .12 169 16 3 112 1.51 .17 .11 130 14 3 153 .85 .11 .13 113 17 3 167 .68 .12 .18 121 10 3 166 .73 .08 .11 121 23 2 154 .79 .16 .21 103 12 3 182 .57 .08 .15 102 13 4 181 .56 .09 .17 E-15 I E-14 I E-13 I E-12 II E-ll II E-10 II E-9 II E-8 II E-7 II E-6 III E-5 IV E-4 IV E-3 V E-2 V E-l V *Number of grains in 300 grains of garnet (Ga), zircon (Zi), tourmaline (To), and hornblende (Hb). 22 ILLINOIS STATE GEOLOGICAL SURVEY TABLE B. - HEAVY MINERAL DATA - (Cont inued) 111 inoian Oulwa sh Sections Sample Unit or * No. No. No. No. Ga Zi+To Zi+To zoce Ga Zi To Hb Hb Hb Ga BREEDS SECTION B-14 Peorian Loess 59 39 44 158 .37 .53 1.41 B-13 Mixed 73 53 42 130 .58 .73 1.27 B-12 II 61 52 71 116 .53 1.06 2.02 B-ll II 63 46 54 137 .46 .73 1.59 B-10 Trans. II-IIl 52 27 34 187 .28 .33 1.17 B-9 III 8 18 4 270 .03 .08 2.75 B-8 III 54 21 16 209 .26 .18 .69 B-7 III 59 17 10 214 .28 .13 .46 B-6 III 27 13 6 254 .11 .07 .70 B-5 III 65 21 9 205 .32 .15 .46 B-4 IV 38 11 10 241 .16 .09 .55 B-3 IV 46 16 9 229 .20 .It .54 B-l IV 64 19 10 207 .31 .14 .45 COUNTRY CLUB SECTION C-16 Farmdale Loess 70 46 51 133 .53 .73 1.39 C-15 Mixed 68 61 60 111 .61 1.09 1.75 C-14 Trans. I-II 71 77 60 92 .77 1.49 1.93 C-13 II 82 59 64 95 .86 1.29 1.50 C-12 II 77 78 60 85 .91 1.62 1.79 C-ll II 82 63 53 102 .80 1.14 1.41 C-10 II 67 48 55 132 .51 .78 1.54 C-9 Trans. II-III 78 29 32 161 .48 .38 .78 C-8 III 45 15 19 221 .20 .15 .76 C-7 III 36 14 11 239 .15 .10 .69 C-5 III 38 16 9 237 .16 .11 .66 C-4 IV 76 14 13 197 .39 .14 .36 C-3 IV 79 31 9 181 .44 .22 .51 C-2 IV 43 14 7 236 .18 .09 .49 * Number of grains in 300 grains of garnet (Ga), zircon (Zi). tourmaline (To), and hornblende (Hb). Illinois State Geological Survey Circular 273 22 p., 12 figs., 2 tables, 1959 CIRCULAR 273 ILLINOIS STATE GEOLOGICAL SURVEY URBAN A '^"ftl^ " 4