IM 124 /*f.6S: Availability of the Danville, Jamestown, Dekoven, Davis, and Seelyville Coals for Mining in Selected Areas of Illinois Christopher P. Korose, Colin G.Treworgy, Russell J. Jacobson, and Scott D. Elrick Illinois Minerals 124 2002 George H. Ryan, Governor Department of Natural Resources Brent Manning, Director ILLINOIS STATE GEOLOGICAL SURVEY William W.Shilts, Chief „ n a IV 4 *' W* Equal opportunity to participate in programs of the Illinois Department of Natural Resources (IDNR) and those funded by the U.S. Fish and Wildlife Service and other agencies is available to all individuals regardless of race, sex, national origin, disability, age, religion, or other non-merit factors. If you believe you have been discriminated against, contact the funding source's civil rights office and/or the Equal Employment Opportunity Officer, IDNR, 524 S. Second, Springfield, Illinois 62701 -1787; 21 7-785-0067; TTY 2 17-782-9 175. This information may be provided in an alternative format if required. Contact the DNR Clearing- house at 217-782-7498 for assistance. DISCLAIMER This manuscript is published with the understanding that the U.S. Government is authorized to reproduce and distribute reprints for governmental use. Cover photo: Surface mining the Dekoven and Davis Coals atjader Coal Company's No. 4 Mine Editorial Board Jonathan H. Goodwin, Chair Michael L. Barnhardt David R. Larson B. Brandon Curry John H. McBride Anne L. Erdmann Donald G. Mikulic William R. Roy ILLINOIS ilBSGS resources *^^ Illinois State Geological Survey Printed by the authority of the State of Illinois 0.5M - 7/02 © Printed on recycled and recyclable paper stock. Availability of the Danville, Jamestown, Dekoven, Davis, and Seelyville Coals for Mining in Selected Areas of Illinois Christopher P. Korose, Colin G.Treworgy, Russell J. Jacobson, and Scott D. Elrick Illinois Minerals 124 2002 George H. Ryan, Governor Department of Natural Resources Brent Manning, Director ILLINOIS STATE GEOLOGICAL SURVEY William W.Shilts, Chief 615 E. Peabody Drive Champaign, Illinois 61820-6964 217-333-4747 http://www.isgs.uiuc.edu ACKNOWLEDGMENTS We are especially appreciative to the following mining experts who gave us information on criteria that limit the availability of coal: Manny Efframian, Tom McCarthy, David Johnson, George Martin, James Niemeyer, and Monna Nemecek of AMAX Coal Company; Greg Bieri and Philip Deaton of Arch Minerals; Dan Pilcher of Arclar Coal Company; Philip Ames, Bruce Dausman, Christopher Engleman, and Christopher Padavic of Black Beauty Coal Company; Brent Dodrill, James Hinz, Edward Settle, and Randy Stockdale of Consolidation Coal Company; S.N. Ghose, Dana Meyers, Marvin Thompson, and John Williams of Cyprus-AMAX Coal Company; Michael Caldwell, Neil Merryfield and Roger Nance of Freeman United Coal Mining Company; Dan Ganey and Thomas Denton of Kerr-McGee Coal Company; Alan Kern, Michael Meighan, and John Popp of MAPCO Coal Inc.; James Grimm of Midstate Coal Company; Jeffrey Padgett of Monterey Coal Company; Eric Quam of Old Ben Coal Company; Michael Anderson, Vick Daiber, Marc Silverman, and Grady White of Peabody Coal Company; Robert Gullic and Walter Lucus of Sahara Coal Company; Steve Short and Dennis Oliver of Sugar Camp Coal Company; Guy Hunt of Turris Coal Company; Douglas Dwosh, Kenneth Ginard, and David Thomas ofWeir International Mining Consultants; Daniel Barkley, Dean Spindler, and Scott Fowler of the Illinois Office of Mines and Minerals; and Robert Bauer of the Illinois State Geological Survey. This project was supported by the U.S. Geological Survey (USGS) , Department of the Interior, under the following agreements: 14-08-0001-A0773, 1 4-08-000 1-A0841, 1434-92-A0940, 1434-93- A1137, 14-94-A1266, 1434-95-A01346, 1434-HQ96AG-01460, 1434-HQ97AG-01759, 1434-98HQAG- 2015, 1434-99HQAG-0081, and 1434-00HQAG-0165. We especially thank Harold J. Gluskoter and M. Devereux Carter of the USGS and Heinz Damberger of the Illinois State Geological Survey (ISGS) for their guidance and support. This study utilized a number of databases compiled over many years by the ISGS Coal Section staff members. Valerie Straayer assisted with the mapping of the Danville, Dekoven, and Davis Coals. Margaret Bargh and Melisa Borino updated the mined areas. Cheri Chenoweth assisted with compiling production statistics. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government. Contents Acknowledgments ii Executive Summary 1 Introduction 3 Coal Resource Classification System 3 Sources of Data, Limitations, and Mapping Procedure 3 Geology and Mining of the Coals 4 Danville Coal 4 Jamestown Coal 5 Dekoven Coal 8 Interval between the Dekoven and Davis Coals 15 Davis Coal 15 Seelyville Coal 15 Coal Quality 21 Rank 21 Sulfur 21 Chlorine 21 Quadrangle Studies 24 Technological and Land-Use Factors that Affect the Availability of Coal for Mining 25 Available Resources 27 Danville Coal 27 Jamestown Coal 33 Dekoven Coal 33 Davis Coal 33 Surface Mining of the Dekoven and Davis Coals 33 Seelyville Coal 38 Conclusions 38 References 39 Appendixes 1 Remaining resources by county and availability by mining method 41 2 Source maps for coal resources 43 Tables 1 Availability of the Danville, Jamestown, Dekoven, Davis, and Seelyville Coals for mining in selected areas of Illinois 2 2 Variation in names of some major coal seams in the Illinois Basin 5 3 Criteria used to define resources available for surface mining in this study 24 4 Criteria used to define resources available for underground mining in this study 25 5 Availability of the Danville Coal by thickness category 28 6 Availability of the Jamestown, Dekoven, Davis, and Seelyville Coals for mining, by thickness category 28 7 Resources of the Dekoven and Davis Coals available for surface mining 33 Figures 1 Extent ofthePennsylvanian System in the Illinois Basin 4 2 North-south cross section of the Pennsylvania!! System in Illinois 4 3 General stratigraphic position of coals mentioned in this report 5 4 Thickness of the Danville Coal 6 5 Depth of the Danville Coal 7 6 Annual production of the Danville Coal in Illinois 8 7 Location of sandstone channels above the Danville Coal 9 8 Thickness of the Jamestown Coal 10 9 Depth of the Jamestown Coal 11 10 Thickness oftheDekoven Coal 12 11 Depth oftheDekoven Coal 13 12 Selected structural features in southeastern Illinois 14 13 Thickness of the interval between the Dekoven and Davis Coals 16 14 Thickness of the Davis Coal 17 15 Depth of the Davis Coal 18 16 Thickness oftheSeelyville Coal 19 17 Depth oftheSeelyville Coal 20 18 Sulfur content of the Danville Coal 22 19 Chlorine content oftheHerrin Coal 23 20 Quadrangle study areas used to identify coal available for mining 26 21 Availability of the Danville Coal for mining in Illinois 27 22 Areas of the Danville Coal available for underground mining 29 23 Areas of the Danville Coal available for surface mining 30 24 Availability of the Jamestown, Dekoven, Davis, and Seelyville Coals for mining in Illinois 31 25 Areas of the Jamestown Coal available for underground mining 32 26 Areas oftheDekoven Coal available for underground mining 34 27 Areas of the Davis Coal available for underground mining. 35 28 Areas of the Dekoven and Davis Coals available for surface mining 36 29 Areas oftheSeelyville Coal available for underground mining 37 30 Availability of coal resources by seam 38 Executive Summary The Danville, Jamestown, Dekoven, Davis, and Seelyville Coals, as mapped in this study, collectively make up about 23% (48 billion tons) of Illinois' original coal resources. However, less than 1% of the original resources of these five seams has been mined. These coal beds are typically thinner and /or deeper than the more exten- sively mined Herrin and Springfield Coals (Treworgyetal. 1999a, 2000). The remaining resources of these five seams include 3.6 billion tons of Danville Coal that is thought to have a medium- to low-sulfur content. The degree to which these coal resources are utilized in the future depends on the availability of deposits that can be mined at a cost competitive with other coals and alternative fuels. This report identifies those resources that have the most favorable geologic and land-use characteristics for mining and alerts mining companies to geo- logic conditions that have the poten- tial for negative impacts on mining costs. Of all five coals included in this study, a total of approximately 17 billion tons are available for mining. "Available" means that the surface land-use and geologic conditions related to mining the deposit (e.g., thickness, depth, in- place tonnage, and stability of bed- rock overburden) are comparable with those of other coals currently be- ing mined in the state. An additional 1 .3 billion tons are avail- able with potential restrictions that make these five coals less desirable for mining, such as the presence of closely spaced oil wells or close prox- imity to rapidly developing urban areas. Technological factors (geologic conditions and economic parameters such as size of reserve block) are the major restriction to mining and re- strict 56% of these combined re- sources. Land-use factors (e.g., towns and highways) restrict 6% of these re- sources. The original resources of the five seams studied in this report indi- vidually range from 3.6 billion to 19.6 billion tons; however, the respective availability of these coals for mining does not correlate to the tonnage of their original resources (table D.The seams are discussed in descending stratigraphic order. The Danville Coal is the third-largest resource (19.6 billion tons) of all coal seams in the state, but only 23% (4.5 billion tons) is available for mining. The majority of the available Danville resources (4.2 billion tons) is available for mining by underground methods, and an additional 300 million tons are available but with potential restric- tions. Approximately 360 million tons are available by surface mining meth- ods. Of the total amount of available Danville Coal, approximately 1 .2 bil- lion tons have a medium- to low-sul- fur content. Technological factors re- strict 69% (13.5 billion tons) of the Danville resources, and land-use fac- tors restrict 6% (1.1 billion tons) . The Jamestown Coal constitutes the eighth-largest resource (3.6 billion tons) of all seams in the state and is available only for underground min- ing. A total of 26% of the resources (about 1 billion tons) is available for mining; 100 million of these tons are potentially restricted by numerous oil wells. Technological factors restrict 62% of the resources, and land-use factors restrict 10%. The Dekoven Coal is the seventh-larg- est resource of all the coal seams in the state, but only 5% (300 million tons) are available for mining. Two hundred million tons of these are available by underground mining methods. Just over 100 million tons of the Dekoven Coal are available by sur- face mining methods, when mined in combination with the underlying Davis Coal. Technological factors restrict 89% of the Dekoven Coal resources, and land-use factors re- strict 4%. The Davis Coal ranks sixth among the state's coal seams in terms of total re- sources (9.6 billion tons), and 49% of this amount (4.7 billion tons) is avail- able for mining. Of the available coal, 4.6 billion tons are available by under- ground methods; an additional 500 million tons are available but with po- tential restrictions. Only about 100 million tons of the Davis Coal are available by surface mining methods, when mined in combination with the overlying Dekoven Coal. Technologi- cal factors restrict 41% of the Davis Coal, and land-use factors restrict 4%. Restrictions to surface mining of the Dekoven and Davis Coals include high stripping ratios and unfavorable drift thickness. The Seelyville Coal is the fifth-largest resource (9.7 billion tons) of all seams in the state: 6.7 billion tons (69% of its original resources) are available for mining. An additional 300 million tons are available with potential restric- tions. The Seelyville Coal is only avail- able by underground mining meth- ods, and major restrictions to mining are the numerous partings within the coal and areas heavily drilled for oil. Whether or not these coal resources are ultimately mined is still dependent upon a variety of other factors that are beyond the scope of this study to assess, including the willingness of lo- cal landowners to lease the coal, de- mand for a particular quality of coal, accessibility of transportation infra- structure, proximity of the deposit to markets, and cost and availability of competing fuels. To avoid high mining costs resulting from unfavorable geo- logic conditions, companies should avoid areas of thick drift and thin bed- rock cover, areas with sandstone in the immediate mine roof, large areas of excessive partings in the coal, and faulted areas. Areas with low-cost, surface-minable resources are limited and will support only small, short- term operations. This report is the third of a series that explains the availability of coal in Illi- nois for future mining. Previous re- ports assessing the availability of the Springfield and Herrin Coals (Treworgyetal. 1999a, 2000) contain important background information explaining the criteria used in this re- port to identify available coal. These statewide assessments of coal re- sources are based on earlier reports that assessed the availability of coal in 2 1 study areas. The study areas were 7.5-minute quadrangles that are rep- resentative of mining conditions found in various parts of the state. Coal resources and related geology were mapped in these study areas, and the factors that restricted the linois State Geological Survey linois Minerals 1 24 Table 1 Availability of the Danville, Jamestown, Dekoven, Davis, and Seelyville Coals for mining in se- lected areas of Illinois (billions of tons). See appendix 1 for a listing of results by county. Potential mining method 1 Su lfur(lb./10 6 BTU) Total Surface Underground 1 .67 >1.67 Danville Coal Original 19.6 4.4 18 3.6 16.0 Mined 0.2 (1) 2 0.1 (3) 0.1 (1) 0.0 0.2 (1) Remaining 19.4 (99) 4.3 (97) 17.9 (99) 3.6 (100) 15.8 (99) Available 4.5 (23) 0.4 (8) 4.2 (23) 1.2 (33) 3.3 (21) Available with conditions 0.3 (1) <0.1 (0) 0.3 (2) 0.1 (3) 0.2 (1) Technological restrictions 13.5 (69) 3.2 (74) 12.5 (69) 2.1 (59) 11.4 (71) Land-use restrictions 1.1 (6) 0.7 (15) 0.9 (5) 0.2 (5) 0.9 (6) Jamestown Coal Original 3.6 <0.1 3.6 *3 Mined 0.0 0.0 0.0 Remaining 3.6 (100) <0.1 3.6 (100) Available 0.9 (26) 0.0 0.9 (26) Available with conditions 0.1 (2) 0.0 0.1 (2) Technological restrictions 2.2 (62) <0.1 (100) 2.2 (62) Land-use restrictions 0.4 (10) 0.0 0.4 (10) Dekoven Coal Original 6.0 0.2 5.9 * Mined 0.1 (1) <0.1 (20) <0.1 (<1) Remaining 5.9 (99) 0.2 (80) 5.9 (100) Available 0.3 (5) 0.1 (75) 0.2 (4) Available with conditions 0.1 (1) 0.0 <0.1 (<1) Technological restrictions 5.3 (89) <0.1 (4) 5.4 (92) Land-use restrictions 0.2 (4) <0.1 (1) 0.2 (4) Davis Coal Original 9.6 0.2 9.6 * Mined <0.1 (1) <0.1 (18) <0.1 (D Remaining 9.5 (99) 0.2 (82) 9.5 (99) Available 4.7 (49) 0.1 (73) 4.6 (48) Available with conditions 0.5 (5) 0.5 (5) Technological restrictions 3.9 (41) <0.1 (8) 4.0 (42) Land-use restrictions 0.4 (4) <0.1 (1) 0.4 (4) Seelyville Coal Original 9.7 _4 9.7 * Mined <0.1 (<1) <0.1 (<1) Remaining 9.7 (100) 9.7 (100) Available 6.7 (69) 6.7 (69) Available with conditions 0.3 (3) 0.3 (3) Technological restrictions 2.1 (22) 2.1 (22) Land-use restrictions 0.6 (6) 0.6 (6) 1 Note: surface and underground resources do not add to the total because coal that lies between 75 and 200 feet deep is included in both categories. 2 Numbers in parentheses are percent of original resources. 3 Asterisk indicates that available information is not sufficient to categorize resources by sulfur content. 4 All of the Seelyville Coal resources lie greater than 200 feet deep and thus were evaluated for underground mining only. Illinois Minerals 1 24 Illinois State Geological Survey availability of coal in the quadrangles weir identified through interviews with more than 40 mining engineers, geolo- gists, and other mining specialists rep- resenting 17 mining companies, con- sulting firms, and government agencies experienced in mining Illinois coals. The major restrictions identified in these individual study areas were used for the statewide assessments of the availability of coals for mining. Introduction This report is the third in a series that assesses the availability of coal re- sources for future mining in Illinois and is patterned after earlier assess- ments. The reader is referred to Treworgy et al. (1999a, 2000) for details on the background of the project and the general criteria used to define re- sources available for mining. Coal Resource Classification System The Illinois State Geological Survey (ISGS) follows the terms and defini- tions of the U.S. Geological Survey (USGS) coal resource classification sys- tem (Wood et al. 1983). With minor modifications to suit local conditions, these definitions provide a standard- ized basis for compilations and com- parisons of nationwide coal resources and reserves. The term "original resources" refers to the amount of coal originally in the ground prior to any mining. In this re- port, the ISGS defines "surface minable coal" as all coal in the ground that is 18 or more inches thick and lies less than 200 feet deep, whereas "underground minable coal" is all coal 28 or more inches thick and lying 75 or more feet deep. Coal 28 or more inches thick and lying from 75 to 200 feet in depth is considered in calculations as being both surface minable and under- ground minable. In recent years, the USGS has pro- moted the idea of further defining the characteristics of resources by dividing remaining resources into two catego- ries: restricted and available (Eggleston et al. 1990). Restricted resources are those that have some land-use or tech- nological restriction that makes it un- likely they will be mined in the foresee- able future. Land-use restrictions in- clude manmade or natural features that are illegal or impractical to disturb by mining. Technological restrictions include geologic or mining-related fac- tors that negatively impact the eco- nomics or safety of mining. Resources in the available category are not neces- sarily economically minable at the present time, but these deposits are expected to have mining conditions comparable with those currently being mined. Determining the actual cost and profitability of these deposits re- quires further engineering and mar- keting assessments and site-specific studies. This study follows the USGS example of dividing resources into categories of available and restricted. The ISGS also uses an additional category called "available with potential restrictions." This term is used to designate re- sources that are not restricted by the land-use or technological restrictions, but that have some known special con- dition that makes them less favorable for mining. Close proximity to rapidly developing urban areas, the presence of a relatively high density of oil wells or test holes, and potentially unstable roof conditions are examples of poten- tial restrictions that have resulted in re- sources being placed in this category. In this study, therefore, remaining re- sources = resources restricted by land use + resources restricted by technol- ogy + resources available with potential restrictions + available resources. The USGS classification system uses the terms "measured," "indicated," and "inferred" to indicate the reliability of resource estimates based on the type and density of data (Wood etal. 1983). The ISGS uses similar categories, which in previous reports have been called Class la, Class lb, and Class Ha (Treworgy etal. 1997b). Because these earlier ISGS categories are essentially equivalent to the USGS categories, the USGS terminology defined by Wood et al. (1983) is used in this report. Collec- tively, the resources in these three cat- egories are termed "identified resources" to distinguish them from resources based on less reliable estimates. Sources of Data, Limitations, and Mapping Procedure Resources of the five coals covered by this report have been mapped by a number of previous studies (appendix 2). The maps used for this study were compiled from data obtained from a variety of public and private sources: drilling logs, core descriptions, and geophysical logs obtained from com- panies and descriptions of mine and outcrop exposures made by ISGS ge- ologists. The maps have varying de- grees of completeness and accuracy, are designed for a regional assessment, and have a scale of 1:500,000. Features or details of features smaller than about 0.5-mile across may not be ac- curately portrayed or may be omitted altogedier. The coal resource maps used for this study are in digital format, which facili- tates map updates, revisions, and ac- cessibility adjustments. When the origi- nal paper maps were digitized into a common digital map database, adjust- ments were commonly necessary in areas where two studies met or over- lapped. Past ISGS studies describe in detail the process of constructing digi- tal coal resource base maps from origi- nal paper sources, and the resulting necessary adjustments made to certain map areas and, therefore, coal tonnage calculations (Treworgy 1997b, Treworgy and Bargh 1982). For this study, resources of the Davis and Dekoven Coals were revised or newly mapped in five counties, and the Danville Coal was newly mapped in two counties utilizing data acquired since the previous investigations. Mi- nor corrections and revisions were made in a number of other counties. New mapping was prioritized in areas where the coals were thought to be of minable thickness and where the den- sity of available coal test data was the greatest. For the Dekoven and Davis Coals, geophysical logs spaced at ap- proximately 3 miles were used in the linois State Geological Survey linois Minerals 1 24 I Extent of Pennsylvanian System Figure 1 Extent of the Pennsylvanian Sys- tem in the Illinois Basin (modified from Treworgy et al. 2000). northern third of the study area to supplement sparse or nonexistent coal test drilling data, and mapping was ex- tended up to 2 miles beyond any given data point. Mined areas were updated to January 1 , 2000, by using maps ob- tained from coal companies. Geology and Mining of the Coals The coal-bearing rocks of Illinois were deposited during the Pennsylvanian Period approximately 295 to 325 mil- lion years ago (Haq and Van Eysinga 1998) . The strata of the Pennsylvanian System underlie about two-thirds of the state. Only the northern fourth of Illinois and narrow belts along the Mis- sissippi, Ohio, and Illinois Rivers have no Pennsylvanian rocks. The coal- bearing strata of Illinois extend into southwestern Indiana and western Kentucky as a single continuous coal field known as the Illinois Basin or Eastern Interior Coal Field (fig. 1 ) . Within the Pennsylvanian strata, coal seams are present as part of cyclic rock sequences called cyclothems — of which a succession of sandstone, shale, limestone, and coal units mark the shifting ancient shoreline environment during a complete cycle of marine in- vasion and retreat ( Jacobson 1973). The seams are not evenly distributed over the approximately 3,000-foot- thick sequence of coal-bearing rocks in Illinois, and most occur in the middle of the Pennsylvanian sequence. These Pennsylvanian coals are continuous over large areas, and they generally crop out along the margins of the basin (fig. 2) , although the thickness of any particular seam may be quite variable. Dozens of coal seams have been mined commercially in Illinois, but only some are important in terms of past and present production. These economi- cally important seams are included in figure 3; in order of geologic age these major seams in Illinois are the Danville (youngest), Herrin, Springfield, Colchester, Seelyville, Dekoven, and Davis Coals. Some of the coals in the Illinois Basin can be correlated across state boundaries; however, the names of these coals are subject to change from one state to another (table 2). In Illinois, the five coals discussed in this report are typically thinner and/or deeper than the more extensively mined Herrin and Springfield Coals that were described previously (Treworgy et al. 1999a, 2000). However, ample resources of these five coals re- main, and their presence in selected areas of the state is discussed herein. Danville Coal The 19.6 billion tons of Danville Coal resources are the third largest in the state and constitute about 9% of the total coal resources. The Danville Coal Member of the Shelburn Formation can be traced throughout two-thirds of the state of Illinois, al- though the coal exceeds 42 inches in thickness (the minimum thickness for coal seams available for underground mining) primarily in a narrow band along the eastern and northern edges of the coal field (fig. 4). Resources of the Danville Coal were mapped by 500 0- ~ -500 o LU •1,000 -1,500 -2,000 ] Quaternary System ZJ Pennsylvanian System 25 Miles i i i i i i Figure 2 North-south cross section of the Pennsylvanian System in Illinois (from Treworgy et al. 2000). The Seelyville Coal is not in- cluded in this cross section. Illinois Minerals 1 24 Illinois State Geological Survey (13 o 2,9 (0 o Table 2 Variation in names of some major coal seams in the Illinois Basin (Jacobson et al. 1 985, Shaver et al. 1 986, Greb et al. 1992). Danville Jamestown Herrin Springfield Houchin Creek Colchester See.yvi..e/£ v k ° ven Figure 3 General stratigraphic position of coals mentioned in this report (bold type). Coals are shown in order of geologic age (youngest seam at top). Formal nomencla- ture is from Jacobson et al. 1985. previous studies along this band and in scattered areas of southern, central, and northwestern Illinois (appendix 2), and for this study in Douglas and Mc Lean Counties using coal test drill- ing data acquired since the earlier investigations. Elsewhere the coal is probably too thin to be of economic interest. The Danville Coal is the youngest of the five coals covered by this report (fig. 3). The coal crops out along the margins of the Illinois Basin and reaches a maximum depth in southeastern Illinois of about 1,300 feet (fig. 5). The Danville Coal has been mined in Illinois for over 100 years (fig. 6), but only about 1% of the original resources has been depleted. The most extensive area of mining was in east-central Illi- nois near the city of Danville where the coal has been mined by both surface and underground methods. The coal was also mined by underground meth- ods at scattered localities in the north- ern part of the state (Colfax and Chenoa in Mc Lean County; Fairbury, Pontiac, and Streator in Livingston County; and several locations in La Salle and Bureau Counties) and has been surface mined at a number of lo- lllinois Indiana Western Kentucky Danville (No. 7) Jamestown Herrin (No. 6) Springfield (No. 5) Colchester (No. 2) Seelyville Dekoven Davis Danville (VII) Hymera (VI) Herrin Springfield (V) Colchester(llla) Seelyville (III) Dekoven Davis Wheatcroft Paradise (No. 12) Herrin (No. 11) Springfield (No. 9) Colchester Dekoven (No. 7) Davis (No. 6) cations in southern and western Illi- nois. Except for mines in east-central Illinois, most large surface mines re- cover the Danville Coal only as part of their operation to remove overburden to mine the underlying Herrin Coal. In many cases, the Danville seam has been considered to be too thin or too poor in quality to justify recovery and was simply discarded in the spoil pile with other rock overburden. In Indi- ana, mines from Terre Haute south- ward in the western and southwestern parts of the state have and continue to work the Danville Coal. During or immediately following the accumulation of the peat that eventu- ally formed the Danville Coal, part of the peat swamp was flooded and cov- ered by a sequence of shale, siltstone, and sandstone. Distributary channels within the deltaic system that depos- ited this sequence are preserved as lin- ear deposits of sandstone in areas of east-central Illinois (fig. 7). This sand- stone is commonly tens of feet above the coal, but in some areas the sand- stone lies only a few feet above or di- rectly on the coal. Thinner coal is shown on some logs where the sand- stone lies directly on the coal, indicat- ing that the top of the seam may have been eroded. Because of the variable spacing be- tween data points used to map re- sources and the relatively narrow sandstone bodies, the locations and lateral extent of the sandstone chan- nels are only generally known, and the continuity of the coal seam below the sandstone is uncertain. An explanation for the channels could be that prior to the Danville deposition, these areas compacted more rapidly and were to- pographically lower than surrounding areas; thus, they received more of the distributary channel sediments. There is no experience mining the Danville Coal in Illinois below the sand- stone channels and only limited experi- ence in Indiana. In the limited Indiana experience, as well as similar situations in Illinois involving the Anvil Rock Sandstone overlying the Herrin Coal, mine productivity was reduced in areas where the sandstone was within about 5 feet of the top of the coal because of unstable roof conditions, wet mining conditions, and abrupt thinning or ab- sence of the coal (ISGS mine notes). Similar mining conditions are antici- pated for the Danville Coal in Illinois where sandstone forms the roof rock or is a short vertical distance above the coal. Jamestown Coal The Jamestown Coal Member of the Shelburn Forma- tion makes up about 2% (3.6 billion tons) of the resources of the state. Al- though the coal has never been mined in Illinois, it has been extensively mined, both at the surface and under- ground, just across the state line in In- diana where it is called the Hymera Coal. The lamestown Coal lies 20 to 50 feet below the Danville Coal and 1 to 10 feet above the Herrin Coal (fig. 3). The Jamestown Coal can be traced as a thin bed — or as coal streaks and carbon- aceous shale, typically a few inches thick — in cores and mine exposures over much of central and southern parts of Illinois, but is known to be greater than 42 inches thick only along the east border of the state in Clark, Illinois State Geological Survey Illinois Minerals 1 24 Coal thickness (inches) Less than 28 28 to 42 42 to 66 Greater than 66 Insufficient thickness data for resource calculation Mined-out areas; Danville Coal Danville Coal eroded A 50 Miles Figure 4 Thickness of the Danville Coal. 6 Illinois Minerals 1 24 linois State Geological Survey Coal depth (feet) Less than 200 200 to 500 500 to 1,000 | Greater than 1 ,000 Figure 5 Depth of the Danville Coal. Mined-out areas; Danville Coal Danville Coal eroded A 50 Miles linois State Geological Survey linois Minerals 1 24 7 8,000.000 7,000,000 6,000,000 5,000,000 - 4,000,000 - 3,000,000 2.000,000 - 1,000,000 (? a'' t?> n'' \° ^ 1° o* 5 ^ ^ i n^ (? (t 5 # ^ A° ^ 1? ^ # ({> Years Figure 6 Annual production of the Danville Coal in Illinois. The // on the x-axis indicates no data for 1902. Crawford, and Lawrence Counties (fig. 8; Treworgy et al. 1997b). In this area of resources, the seam ranges in depth from approximately 150 to 1,000 feet (fig. 9). Lack of mining of the Jamestown Coal in Illinois is attributed to its being shallower and thicker just across the state line in Indiana. In addi- tion, thicker Herrin and Danville Coals are closer to the surface near this area. In Kentucky, the Jamestown is called the Paradise (No. 12) Coal. Thick depos- its occur in the western part of the state, where the Paradise has been strip mined extensively in a three-county re- gion (Grebetal. 1992). Because of the lack of any past mining of the Jamestown Coal in Illinois, the mining conditions that will be encoun- tered can only be inferred from nearby mines in Indiana. Harper (1988, 1994) describes underground mining of the Hymera in Indiana as being limited by geologic conditions. The Thunderbird Mine, the last major underground mine active in the Hymera and the closest mine to Illinois, had a roof se- quence consisting of laminated gray shale and sandstone. Mining problems encountered included failure of the shale after exposure to the atmo- sphere, seepage of water from the sandstone where it closely overlies the coal, and features described as "faults" or "roof rolls." Miners use these latter terms to refer to a variety of displace- ments, discontinuities, and irregulari- ties in the coal and overlying roof strata. Similar conditions were re- ported in other underground mines in the Hymera Coal. Many of these mines were very shallow, and some roof sta- bility problems may have been caused or exacerbated by insufficient bedrock cover or weathering of the bedrock cover. Some resources of Jamestown Coal in Illinois will probably be found to be difficult or costly to mine be- cause of some of these geologic condi- tions. Because of the scarcity of suit- able drilling records and lack of mining experience, it is impossible at this time to delineate the areas or estimate the amount of resources that will be af- fected by adverse geologic conditions. Dekoven Coal The 6 billion tons of Dekoven Coal resources are the sev- enth largest in Illinois and make up about 3% of the state's total coal re- sources. Earlier studies of the coal (Cady 1952, Smith 1957, Jacobson 1993) were confined to the southern third of the study area (Franklin, Williamson, Saline, and Gallatin Counties) . Using new subsurface data, this study ex- panded mapping of the Dekoven to in- clude White, Hamilton, Wayne, Edwards, and Wabash Counties. The Dekoven Coal Member of the Carbondale Formation (fig. 3) is wide- spread across southeastern Illinois. Jacobson (1987) found the Dekoven Coal and the underlying Davis Coal to be equivalent to the benches of the Seelyville Coal that were formed by the presence of several clastic partings to the north and east of this study area. The Dekoven Coal ranges from 28 to 42 inches thick over approximately two- thirds of the area studied for this re- port and in smaller areas up to 66 inches in thickness (fig. 10). The Dekoven increases in depth from its crop line northward (fig. 11) and reaches depths exceeding 1 ,400 feet to- ward the center of the deep basin, or Fairfield Basin (fig. 12), and depths ex- ceeding 1 ,000 feet occur in smaller ar- eas of downdropped fault blocks (gra- bens) in Gallatin and White Counties. In southeastern Illinois, a parting oc- curs in the Dekoven Coal, producing a split of coal from the main bench of the Dekoven that Jacobson (1993) re- ferred to as the lower Dekoven Coal. Smith (1957) and Jacobson (1987) had recognized this split but had not Illinois Minerals 1 24 Illinois State Geological Survey COLES EDGAR _ FLCLARK CUMBERLAND = % JASPER CRAWFORD RICHLAND Sandstone present within 5 feet above Danville Coal No sandstone present Danville Coal eroded A 15 Miles ~m Figure 7 Location of sandstone channels above the Danville Coal. linois State Geological Survey Illinois Minerals 1 24 Coal thickness (inches) Less than 28 28 to 42 42 to 66 Greater than 66 Insufficient thickness data for resource calculation Jamestown Coal not mapped A 15 Miles Figure 8 Thickness of the Jamestown Coal. 1 Illinois Minerals 1 24 Illinois State Geological Survey COLES CUMBERLAND JASPER CLAY RICHLAND CLARK EDWARDS Coal depth (feet) Less than 200 200 to 500 500 to 1,000 Jamestown Coal not mapped A 15 Miles Figure 9 Depth ot the Jamestown Coal. linois State Geological Survey linois Minerals 1 24 11 Coal thickness (inches) Less than 28 28 to 42 42 to 66 Insufficient thickness data for resource calculation Mined-out areas; Dekoven Coal Dekoven Coal eroded or not mapped A 25 Miles Figure 10 Thickness of the Dekoven Coal. 1 2 Illinois Minerals 124 linois State Geological Survey MARION COAL NOT MAKPED JEFFERSON CLAY RICHLAND WAYNE LAWRENCE UNION PULASKI Coal depth (feet) Less than 200 200 to 500 500 to 1,000 Greater than 1 ,000 Mined-out areas; Dekoven Coal Dekoven Coal eroded or not mapped A 25 Miles Figure 11 Depth of the Dekoven Coal. Illinois State Geological Survey Illinois Minerals 124 13 MONTGOMERY WASHINGTON Dekoven/ Davis Coals Seelyville Coal Structural features Extent of mapping, Dekoven/Davis and Seelyville Coals Figure 12 Selected structural features in southeastern Illinois. A 25 Miles 1 4 Illinois Minerals 1 24 Illinois State Geological Survey mapped it in detail prior to the 1993 study byjacobson. The lower Dekoven is typically less than 28 inches thick in most of the study area, and the rock parting dividing the Dekoven Coal in- creases in thickness to the north- northeast from a feather edge to more than 40 feet thick (Jacobson 1993). New subsurface data suggest that this part- ing extends throughout the northeast- ern portion of the study area and thins northeastward toward the eastern shelf of the Illinois Basin. The Dekoven Coal is typically overlain by either medium to dark gray silty shale and siltstone or by massive, thick sandstone. These shales, siltstones, and sandstones are of variable lateral ex- tent and are not easily mappable, but such areas of lateral variation com- monly have unstable roof conditions. Thick, well-cemented sandstone can produce a strong roof and may exist in some areas over the Dekoven, but the common presence of shaley sand- stones, siltstones, and shales will likely reduce the competence of the Dekoven roof. Two of the three older underground mines in the Dekoven Coal reported water problems that may have been related to porous sand- stones, fracturing, faulting, or a combi- nation of such factors (unpublished mine notes, ISGS Coal Section). Nearly all of the mining in the Dekoven Coal has occurred along its crop line in the southern part of the study area. The Dekoven Coal was often mined along with the underlying Davis Coal because, in this area, these coals are found with the interval between them averaging 25 feet thick. Most mining to date has been in surface mines, but some small underground mines have operated in Gallatin and Saline Coun- ties. The Dekoven Coal has been mined extensively in western Kentucky, both underground and in surface mines. Interval between the Dekoven and Davis Coals The interval between the main bench of the Dekoven Coal and the underlying Davis Coal ranges from less than 20 feet to more than 60 feet thick over much of the report area; the thinner areas occur to the south- southwest and northeast (fig. 13). The interval between the two coals thins dramatically coming out of the deeper basin where the strata rise up over the I a Salle Ant icli in iiium (fig. 12), and on the eastern shelf of the basin these two coals appear to merge to form the Seelyville (Jacobson 1987). Over much of the northern half of the study area, the interval thickness is well over 60 feet, and this interval between the Dekoven and underlying Davis Coal includes the clastic parting within the Dekoven Coal. Here, the interval be- tween the Davis and the lower split of the Dekoven averages 10 feet, which is significantly less than in areas where the Dekoven parting is absent and the interval thickness averages 20 to 25 feet. Where the split in the Dekoven is absent, the general lithology of the in- terval between the Davis and Dekoven is sandstone above the roof shales of the Davis Coal. This sandstone seems to be mostly absent, however, where the overlying Dekoven is split. Thus, where this sandstone thins or is absent, the interval thickness between the Davis and the lower bench of the Dekoven is also thinner. Davis Coal The 10 billion tons of Davis Coal resources represent the sixth largest in the state and constitute roughly 5% of the total coal resources. Previous studies of the coal (Cady 1952, Smith 1957, Jacobson 1993) were lim- ited to southeastern Illinois, specifically Franklin, Williamson, Saline, and Gallatin Counties. New subsurface data have expanded mapping of the Davis northward to includeWhite, Hamilton, Wayne, Edwards, and Wabash Counties. The Davis Coal Member of the Carbondale Formation (fig. 3) is the thickest and most widespread coal he- low the Colchester Coal in southeast- ern Illinois. The I )a\ is is typically 42 to 66 inches thick over roughly half of the study area, and, in smaller areas, the coal is greater than 66 inches thick. In other areas, the Davis is thinner, typi- cally ranging from less than 28 inches to 42 inches thick (fig. 14). The Davis Coal increases in depth from its crop line northward and reaches depths of nearly 1,500 feet toward the center of the deep basin, and depths exceeding 1 ,000 feet occur in smaller areas of downdropped fault blocks (grabens) in Gallatin and White Count ies ( fig. 1 5) . The I )avis ( :oal is generally overlain by shale, which core, gamma log, and mine data indicate as black, very fissile, carbonaceous, and marine in origin. This shale averages 5 feet thick over much of the study area. I lowever, in smaller areas, gray silty shales or silt- stones occur directly overlying the Davis. This shale, in turn, is overlain by a variable succession of gray shale, silt- stone, and sandstone. Above some other coals, black fissile shale is over- lain by marine limestone. Although black fissile shale makes a fairly com- petent mine roof, the general strata overlying the Davis are not as compe- tent as those over other coals where a hard marine limestone is present near the coal. Where planar-bedded sand- stone with shale partings is present, roof stability is often even further re- duced, and sandstones within 5 feet above the coal can be likely sources of water problems within a mine. Nearly all of the mining in the Davis Coal has occurred along its crop line in the southern part of the study area. The Davis Coal was often mined along with the overlying Dekoven Coal be- cause, in this area, they average 25 feet apart. As with the Dekoven Coal, most mining to date has been in surface mines, but some small underground operations are found in Gallatin and Saline Counties. At the time of this re- port, a larger underground operation was mining the Davis Coal in Gallatin County near the Eagle Valley area. Also, numerous surface and underground operations mine the Davis Coal in western Kentucky. Seelyville Coal The Seelyville Coal Member of the Carbondale Formation underlies approximately 1 ,900 square miles in central and eastern Illinois and contains about 5% (10 billion tons) of the state's resources. The coal is 42 to 66 inches thick over much of the study area, and, in several large areas, the seam is greater than 66 inches thick (fig. 16). The coal ranges in depth from greater than 200 feet along the eastern edge of the state to about 1 ,500 feet in the central part of the basin (fig. 17). The coal is found at the same strati- graphic position as the Dekoven and Davis Coals in southern Illinois (fig. 3) , and subsurface correlation by lacobson (1987) indicated that upper linois State Geological Survey linois Minerals 1 24 15 MARION COAL JEFFERSON WAYNE NOT MAPPED LAWRENCE (FRANKLIN Interval UNION PULASKI WILLIAMSON mapped Interval thickness (feet) Less than 20 20 to 40 40 to 60 Greater than 60 Dekoven and Davis Coals eroded or not mapped A 25 Miles Figure 13 Thickness of the interval between the Dekoven and Davis Coals. 1 6 Illinois Minerals 1 24 Illinois State Geological Survey MARION CLAY RICHLAND L NOT MARPED LAWRENCE Coal thickness (inches) Less than 28 28 to 42 42 to 66 Greater than 66 Insufficient thickness data for resource calculation Mined-out areas; Davis Coal Davis Coal eroded or not mapped A 25 Miles Figure 14 Thickness of the Davis Coal. linois State Geological Survey Illinois Minerals 1 24 17 Coal depth (feet) Less than 200 200 to 500 500 to 1,000 Greater than 1 ,000 Mined-out areas; Davis Coal Davis Coal eroded or not mapped A 25 Miles Figure 15 Depth of the Davis Coal. 1 8 Illinois Minerals 124 Illinois State Geological Survey DE WITT MACON PIATT MOULTRIE SHELBY COAL rETTE THIN EFFING I- CLAY CHAMPAIGN VI HMILION M :oal o o o NOT APPED DOUGLAS ABSENT WAYNE Coal thickness (inches) Less than 28 28 to 42 42 to 66 Greater than 66 Sandstone channel; no coal Extent of mapping of Seelyville Coal A 25 Miles Figure 16 Thickness of the Seelyville Coal. linois State Geological Survey linois Minerals 1 24 19 SHELBY MOULTRIE COAL FAYETTE J H I M CHAMPAIGN VERMILION M COM o ° o ° ° o DOUGLAS COAL Coal depth (feet) 200 to 500 500 to 1,000 1,000 to 1,500 Extent of mapping of Seelyville Coal A 25 Miles Figure 17 Depth of the Seelyville Coal. 2 Illinois Minerals 1 24 Illinois State Geological Survey and lower benches of the Seelyville are correlative with the Dekoven and I )avis Coals, respectively. The Seelyville has been extensively mined both at the surface and underground in western Indiana. The only mining of this seam in Illinois was in Edgar County, where two underground mines based in Indi- ana extended their works a few hun- dred feet into Illinois. The seam has re- ceived little attention from Illinois min- ing companies because of the availabil- ity of abundant resources in shallower seams, such as the Herrin and Spring- field Coals. The Seelyville Coal commonly has one or more shale partings. The thickest partings are usually in the middle or upper part of the seam and range from a few inches to several feet thick. Most of the Seelyville resources were mapped using geophysical logs from oil test holes (Treworgy 1981). These logs seldom had a resolution suitable for detecting partings less than 6 inches thick, so the number and extent of these thinner partings are unknown. In areas where partings exceeded about 2 feet in thickness, only the thickest bench of coal, commonly the lower bench, was considered a resource. The resolution and density of drilling records used to map the Seelyville re- sources were not sufficient to delineate areas with multiple, thin partings. Our quadrangle studies found that exces- sive parting material is a common problem with the Seelyville Coal. In this report, total available tonnage of coal has been reduced by 20% to represent the possible amount of resource that may be unavailable because of excess parting material. As with the Jamestown Coal, the lack of any history of mining the Seelyville Coal in Illinois makes it difficult to evaluate how geologic conditions such as roof stability and the presence of sandstone in the roof strata may affect the availability of coal. Treworgy ( 1 98 1 ) described three types of strata overly- ing the coal that consist of various se- quences of shales, claystones, and sandstones. None of these sequences clearly makes an excellent mine roof. Harper (1985) noted that Indiana mines nearest Illinois in the Seelyville (theTalleydale and Green Valley Mines, in northwest Vigo County) reported common problems with roof control such as weakness of laminated sand- stones upon exposure to air, and "squeezes," or the sinking of support pillars into the soft, unconsolidated claystones underlying the coal, which often led to constricted mine openings and the weakening of the nearby roof. Also, the map of the Green Valley Mine notes water in at least one location. Thus, for the Seelyville Coal in Illinois, it is reasonable to expect some loss of resources caused by adverse geologic conditions. Coal Quality The quality of coal was not considered as a factor in determining its availabil- ity. Although coal quality is an ex- tremely important factor in individual sales contracts and the magnitude of demand for a particular coal, availabil- ity for mining of a specific resource cannot be ruled out based strictly on quality. Coal washing, blending with other seams, and other techniques can be used to mitigate some undesirable quality characteristics of coals. Be- cause most Illinois coal resources have a relatively high-sulfur content, the de- mand for these resources is currently limited. However, the market for high- sulfur coal, although reduced in size, is expected to continue and may increase as power plants with new emission control technologies become available. Rank Illinois coals are high-volatile, bituminous coals that range in rank from rank A in the southeastern corner of the state to rank C in the northwest- ern two-thirds of the state (Treworgy 1997b). Over the same area, heat con- tent ranges from more than 25 million BTU per ton to less than 20 million BTU per ton (as received). Most Danville and Jamestown resources are rank C, and most Seelyville resources are rank B. The southernmost Dekoven and Davis resources are rank A. Sulfur The sulfur content of Illinois coals is closely related to the deposi- tional history of the coal and the roof strata (Gluskoter and Simon 1968, Treworgy and Jacobson 1986). In areas where the peat swamp was inundated with marine waters, the sulfur content of the coal is commonly in the range of 3 to 5% (as-received basis, equivalent LIBRARY to 2.5 to 5 pounds of sulfur per million BTU). In these areas, the coal is typi- cally overlain by a sequence of marine rocks including black shale and lime- stone. In areas where the peat had been buried by a thick (more than 20 feet) layer of sediments (fresh water or brackish water and estuarine or deltaic clastic sediments) before or shortly af- ter the swamp was inundated by ma- rine waters, the sulfur content of the coal is generally less than 2.0% and may be as low as about 0.5%. Of the five coals covered in this report, only the Danville Coal has been con- firmed by analyses to have resources with a low-sulfur content. Based on the geology associated with these deposits, the Danville Coal is projected to have a low- to medium-sulfur content in east- ern Clark, Crawford, and Lawrence Counties in east-central Illinois (fig. 18). The sulfur content is inferred to be as low as about 0.5% (as-received basis), the lowest sulfur deposits being adja- cent to the border with Indiana. Where the Danville Coal has been sampled elsewhere in the state, the coal has a high-sulfur content (3 to 5% sulfur, as received). Few analyses are available of the lamestown, Dekoven, Davis, and Seelyville Coals in Illinois, and all of those report high-sulfur contents of 3 to 5% (as received). However, these coals are known have low- to medium- sulfur contents in areas of Indiana ( Wier 1973), and geologic conditions suggest that some localized lower- sulfur deposits could exist in Illinois. Chlorine The chlorine content of Illi- nois coals is loosely correlated to depth, and, for the Herrin Coal, chlo- rine increases from less than 0.1% (as received) at shallow depths along the margins of the basin to more than 0.4% in the central part of the basin (fig. 19, Chou 1991). Few analyses for chlorine are available for the coals covered by this report. Because chlorine is thought to be related to basin fluids, not coal genesis, the Danville and Jamestown Coals are predicted to have chlorine contents similar to that of the underly- ing Herrin Coal. The Seelyville, Dekoven, and Davis Coals should have slightly higher chlorine levels. Based on this projection, some resources of the Illinois State Geological Survey OCT 2 3 2002 IL GEOL SURVEY Illinois Minerals 1 24 2 1 Sulfur (pounds per million Btu) I Less than 0.6 0.6 to 1.67 1.67 to 2.5 Greater than 2.5 A Danville Coal eroded 30 Miles Figure 18 Sulfur content of the Danville Coal. 2 2 Illinois Minerals 1 24 Illinois State Geological Survey Chlorine (percent) Less than 0.1 0.1 to 0.2 0.2 to 0.3 0.3 to 0.4 Greater than 0.4 A 50 Miles Subcrop of the Herrin Coal Figure 19 Chlorine content of the Herrin Coal (from Chou 1991) linois State Geological Survey linois Minerals 1 24 2 3 Table 3 Criteria 1 used to define resources available for surface mining in this study. Technological restrictions Minimum seam thickness 18 inches Maximum depth 200 feet Maximum unconsolidated overburden 60 feet Stripping ratio 2 Maximum 25:1 Maximum average 20:1 Minimum size of mine reserve (clean coal) Cumulative tonnage needed to support a mine and preparation plant 10 million tons Individual block size (thousands of tons) Less than 50 feet of overburden 150 More than 50 feet of overburden 500 Land-use restrictions (width of unminable coal around feature) Cemeteries not used State parks and preserves 100 feet Railroads 1 00 feet Federal and state highways 1 00 feet Other paved roads not used Major airports 100 feet High-voltage transmission towers not used Pipelines 100 feet Underground mines 200 feet Towns 0.5 miles Available with potential restrictions Only if surface-mined in combination with overlying or underlying seam identified 3 Potential land-use conflicts All otherwise available surface minable coal in areas where land-use patterns are incompatible with mining identified 1 See previous investigations in this series for a detailed explanation of differences in criteria (Treworgy et al. 1999a, 2000). 2 Cubic yards of overburden per ton of raw coal; volumes and weights not adjusted for swell factors or cleaning losses. 3 The Danville Coal was considered to be available regardless of stripping ratio if the under- lying Herrin Coal was available for surface mining. The Davis and Dekoven Coals are commonly mined together; thus, their combined tonnage and overburden were used to calculate stripping ratio. Danville and Jamestown Coals in east- central Illinois and much of the re- sources of Seelyville Coal may have chlorine levels above those of other coals commonly used in current Illi- nois markets. Although the chlorine content of British coals has been cor- related with corrosion and fouling of high-temperature boilers, no studies have found such a correlation with re- spect to chlorine in coals from Illinois (Monroe and Clarkson 1994, Chou et al. 1998, 1999). Quadrangle Studies The criteria defining available coal re- sources were developed through a se- ries of 21 assessments of 7. 5-minute quadrangles (fig. 20; Jacobson et al. 1996; Treworgy etal. 1994, 1995, 1996a, 1996b, 1997a, 1998, 1999b; Treworgy 1 999; Treworgy and North 1 999) . These assessments included interviews with more than 40 mining engineers, geolo- gists, and other mining specialists rep- resenting 17 mining companies, con- sulting firms, and government agencies actively involved in the Illinois coal in- dustry. Additional background of this program and a detailed description of the framework for the investigations in Illinois are provided in previous re- ports (e.g., Treworgy et al. 1994). 24 Illinois Minerals 1 24 Illinois State Geological Survey Table 4 Criteria used to define resources available for underground mining in this study. Technological restrictions Minimum seam thickness Minimum bedrock cover Minimum ratio of bedrock to unconsolidated overburden Minimum interburden between minable seams: Minimum size of mining block (clean coal) Faults (width of zone of no mining) Cottage Grove Fault System Master fault Subsidiary faults Rend Lake Fault System Centralia Fault Wabash Valley Fault System Sandstone within 5 feet of top of coal' Partings Land-use restrictions (width of unminable coal around feature) Surface and underground mines Towns Subdivisions Churches and schools Cemeteries High-voltage transmission towers Interstate highways Major airports Dams Closely spaced oil wells 42 inches 75 feet 1:1 40 feet 40 million tons 500 to 1 ,000 feet 100 feet 200 feet 300 feet 800 feet Danville tonnage reduced 25% to account for areas of unstable roof or eroded coal Seelyville available tonnage reduced 20% to account for areas unminable because of excessive thickness of parting material 200 feet Ofeet not used not used not used not used 100 feet 100 feet 100 feet <7 wells/40 acres Available with potential restrictions Closely spaced oil well Potential land-use conflicts Potentially adverse mining conditions Bedrock cover 4 to 7 wells/40 acres all otherwise available underground minable coal within areas where land-use patterns are incompatible with mining Danville Coal areas with sandstone within 5 feet of coal (75% remain- ing after initial tonnage reduction); all available Seelyville Coal, due to unmapped partings greater than minimum, but <100 feet Danville Coal only. Although all coals in this study may have this condition, the location of sandstone has been mapped only for the Danville Coal. Technological and Land- Use Factors that Affect the Availability of Coal for Mining The criteria used in this study to define available and restricted resources are a composite set of rules based on our in- terviews with mining companies, ob- servations of mining practice, and the assessments of the 2 1 quadrangles. A detailed description of most of these criteria and their effects on mining was given in previous reports in this series (Treworgyetal. 1999a, 2000). Criteria unique to coals covered by this report (e.g., sandstone overlying the Danville Coal and partings in the Seelyville Coal) are described in the Geology and Min- ing section. In tables 3 and 4, the criteria are orga- nized according to the relevant mining methods (surface or underground mining) as currently practiced in Illi- nois. Because surface mining can be used to mine coal lying as deep as 200 feet and underground mining can be used to extract coal lying as shallow as about 75 feet (if there is sufficient bed- rock), resources that are 75 to 200 feet deep were evaluated for their availabil- ity for both surface and underground mining. Illinois State Geological Survey Illinois Minerals 1 24 2 5 A 50 Miles Extent of Pennsylvanian strata \/ County boundary I I Quadrangle study areas Extent of coals covered in this report Danville Coal Jamestown Coal Dekoven and Davis Coals Seelyville Coal Snyder/ /est Union Vincennes [Mt. Carmel Obion South Shawneetown Figure 20 Quadrangle study areas used to identify coal available for mining. 2 6 Illinois Minerals 1 24 linois State Geological Survey This study does not consider the avail- ability of coal that could be mined us- ing an auger or highvvall miner. Those techniques, which allow additional ton- nages of coal to be recovered from the final cut of a surface mine, have been used on a limited basis in Illinois. In many cases, this coal will be minable by underground methods. Most of the factors that restrict underground min- ing, except for seam thickness, also re- strict auger or highwall mining. The amount of additional tonnage that is recoverable by these methods is prob- ably not significant. Most technological or land-use factors that restrict mining are based on eco- nomic and social considerations and are not absolute restrictions on mining. Companies can choose to mine under- ground in areas of severe roof or floor conditions or thin seams if they are willing to bear the higher operating costs, interruptions and delays in pro- duction, and lower employee morale that result from operating in these conditions. It is possible to mine through or under most roads or under small towns if a company is willing to invest the time and expense necessary to gain approval from the appropriate governing units or individual landown- ers and to mitigate any damage. The maximum stripping ratio is strictly an economic limit, and areas of coal with high stripping ratios may be more eco- nomical to mine by underground methods or may remain unmined until the market price for coal increases relative to production costs. Similarly, previous economic and social condi- tions have, at times, enabled compa- nies to mine in areas where factors are now restrictive. The current highly competitive price environment in the coal industry, which makes coal that is more expensive to mine uneconomic, is expected to prevail in the Illinois Ba- sin indefinitely. Therefore, the criteria used to determine available coal for this report are likely to cover mining conditions for the foreseeable future. Available Resources Danville Coal Of the original resources of Danville Coal, 4.5 billion tons (23%) are available for mining (fig. 21 A). Of these available Land-use restrictions 1.1 bt 6% Mined or lost 0.2 bt 1% A. Total availability Block size, sandstone, and faults 6% Available with potential restrictions 0.3 bt 1% /Land-use restrictions 5% / Thin \ \ / interburden \ \ 16% \J \ Thin / \ bedrock / c \ cover 18% / Available ^ 23% * Available with potential r restrictions / 2% )oal <42 inches / thick 29% / r~ Mined or lost / 1% ] Technological restrictions B. Underground (based on 18 billion tons) Thick unconsolidated overburden 7% Block size <1% Available with potential restrictions 1% Mined or lost 3% Other land-use restrictions 4% 1 Technological restrictions ] Land-use restrictions C. Surface (based on 4.4 billion tons) Figure 21 Availability of the Danville Coal for mining in Illinois (bt = billion tons). linois State Geological Survey linois Minerals l 24 2 7 Table 5 Availability of the Danville Coal by thickness category (billions of tons). Danville Coal 18-28 inches 28-42 inches 42-66 inches >66 inches Total Original 1.3 9.5 8.0 0.8 19.6 Mined <0.1 (3)' <0.1 (<1) <0.1 (<1) 0.1 (15) 0.2 (1) Remaining 1.2 (97) 9.5 (100) 8.0 (100) 0.7 (85) 19.4 (99) Available 0.1 (8) <0.1 (1) 4.0 (50) 0.4 (46) 4.5 (23) Available with conditions <0.1 (1) 0.0 0.2 (2) <0.1 (4) 0.3 (1) Technological restrictions 1.0 (77) 8.8 (93) 3.5 (44) 0.2 (26) 13.5 (69) Land-use restrictions 0.1 (11) 0.6 (6) 0.3 (4) 0.1 (9) 1.1 (6) Numbers in parentheses are percent of original resource. Table 6 Availability of the Jamestown, Dekoven, Davis, and Seelyville Coals for mining, by thickness cate- gory (billions of tons). 18-28 i nches 28-42 i nches 42-66 i nches >66 inches Total Jamestown Coal Original 0.1 1.3 2.0 0.2 3.6 Mined 0.0 0.0 0.0 0.0 0.0 Remaining 0.1 (100) 1 1.3 (100) 2.0 (100) 0.2 (100) 3.6 (100) Available 0.0 0.0 0.9 (44) <0.1 (11) 0.9 (26) Available with conditions 0.0 0.0 0.1 (3) 0.0 0.1 (2) Technological restrictions <0.1 (93) 1.1 (84) 0.9 (45) 0.2 (88) 2.2 (62) Land-use restrictions <0.1 (7) 0.2 (16) 0.2 (8) <0.1 (1) 0.4 (10) Dekoven Coal Original 0.1 4.8 1.1 6.0 Mined <0.1 (56) <0.1 (1) <0.1 (1) 0.1 (1) Remaining <0.1 (44) 4.8 (99) 1.1 (99) 5.9 (99) Available <0.1 (37) 0.1 (2) 0.2 (19) 0.3 (5) Available with conditions 0.0 0.0 0.1 (2) 0.1 (1) Technological restrictions <0.1 (7) 4.5 (92) 0.8 (77) 5.3 (89) Land-use restrictions 0.0 0.2 (5) <0.1 (1) 0.2 (4) Davis Coal Original 3.5 5.8 0.3 9.6 Mined <0.1 (1) 2 <0.1 (1) 0.0 <0.1 (D Remaining 3.5 (99) 5.7 (99) 0.3 (100) 9.5 (99) Available <0.1 (1) 4.5 (77) 0.2 (84) 4.7 (49) Available with conditions 0.0 0.5 (9) <0.1 (10) 0.5 (5) Technological restrictions 3.3 (94) 0.5 (9) <0.1 (2) 3.9 (41) Land-use restrictions 0.2 (4) 0.2 (4) <0.1 (4) 0.4 (4) Seelyville Coal Original _3 <0.1 7.0 2.7 9.7 Mined 0.0 0.0 <0.1 (<1) <0.1 (<1) Remaining <0.1 (100) 7.0 (100) 2.7 (100) 9.7 (100) Available 0.0 4.8 (69) 1.9 (69) 6.7 (69) Available with conditions 0.0 0.2 (3) 0.1 (3) 0.3 (3) Technological restrictions <0.1 (100) 1.6 (22) 0.5 (20) 2.1 (22) Land-use restrictions 0.0 0.4 (6) 0.2 (8) 0.6 (6) 1 Numbers in parentheses are percent of original resources. 2 Minimum surface minable thickness category; only coal less than 200 feet deep was evaluated. 3 Minimum surface minable thickness category. As all of the Seelyville Coal resources lie greater than 200 feet deep, coal in the 18- to 28-inch thickness range was not evaluated. 28 Illinois Minerals 1 24 Illinois State Geological Survey TAZEWELL MONTGOMERY WASHINGTON CHAMPAIGN CUMBERLAND 1 .. Danville Coal Available Available with low- to medium-sulfur coal Available with potential restrictions Restricted or mined out Danville Coal eroded A 30 Miles Figure 22 Areas of the Danville Coal available for underground mining. linois State Geological Survey linois Minerals 1 24 2 9 WnSstoN ^~^ A. Northern Illinois WILLIAMSON v .. 10 Miles SALINE 3* POPE GALLATIN w HARDIN B. Southern Illinois Danville Coal Available I Available with potential restrictions | | Restricted or mined out Danville Coal eroded Figure 23 Areas of the Danville Coal available tor surface mining. 30 Illinois Minerals 124 Illinois State Geological Survey Land-use restrictions 0.4 bt 10% Mined or lost 0.1 bt 1% Available 0.3 bt 5% Land-use restrictions 0.2 bt 4% Available with potential restrictions 0.1 bt <2% Available with potential restrictions 0.1 bt 1% A. Jamestown Coal B. Dekoven Coal Land-use restriction 0.4 bt 4% Mined or lost <0.1 bt 1% Available with potential restrictions 0.3 bt 3% Land-use restrictions 0.6 bt 6% Mined or lost <0.1 bt <1% Available with potential restrictions 0.5 bt 5% C. Davis Coal D. Seelyville Coal Figure 24 Availability of the Jamestown, Dekoven, Davis, and Seelyville Coals for mining in Illinois (bt = billion tons). resources, 4 billion tons are 42 to 66 inches thick, and 400 million tons are greater than 66 inches thick (table 5). Of available Danville Coal resources, 1 .2 billions tons have a medium- to low-sulfur content (less than 1.67 pounds of sulfur per million BTU). An additional 300 million tons are available but with potential restrictions. Geo- logic or land-use conditions may in- crease the cost of mining. These areas include those that have a medium den- sity of oil wells (4 to 7 wells per 40 acres), 75 to 100 feet of bedrock, sand- stone within 5 feet of the top of the coal, or location near rapidly develop- ing areas. Technological factors restrict 69% of the resources (13.5 billion tons), and land use restricts 6% (1.1 billion tons). About 18 billion tons of the original Danville Coal resources lie at depths greater than 75 feet and are potentially minable by underground methods. Of these, 4 billion tons (23%) are available for underground mining, and an addi- tional 300 million tons (2%) are avail- able with potential restrictions (fig. 2 IB). The available resources lie in the eastern and north-central parts of the state (fig. 22). Technological factors restrict 69% (12.5 billion tons) of the underground min- able resources, and land use restricts 5% (fig. 2 1 B) . The major technological restrictions are coal less than 42 inches thick (29%), thin bedrock and/or thick unconsolidated overburden (18%), and thin interburden between the Danville Coal and resources in underlying coals (16%). Mining blocks of insufficient size and sandstone in the immediate roof restrict a total of almost 6% of the resources. About 4.4 billion tons of the original Danville Coal resources lie at depths linois State Geological Survey linois Minerals 124 3 1 COLES CUMBERLAND JASPER RICHLAND ^^ CLARK CRAWFORD EDWARDS \ WABASH LAWR Jamestown Coal B Available Available with potential restrictions Restricted Jamestown Coal not mapped A 15 Miles Figure 25 Areas of the Jamestown Coal available for underground mining. 3 2 Illinois Minerals 1 24 linois State Geological Survey Table 7 Resources of the Dekoven and Davis Coals available for surface mining (millions of tons). Surface minable coal Dekoven Coal Davis Coal Total Original 158 202 360 Mined 31 (20)' 37 (18) 68 (19) Remaining 127 (80) 165 (82) 292 (81) Available 118 (75) 148 (73) 266 (74) Available with conditions Technological restrictions 7 (4) 15 (8) 22 (6) Land-use restrictions 2 (1) 2 (1) 4 (1) Numbers in parentheses are percent of original resources. shallow enough to be considered for surface mining (less than 200 feet deep). Of these, 360 million tons (about 8%) are available for surface mining (fig. 2 1C). An additional 4 million tons are available if the Danville is mined in conjunction with the underlying Herrin Coal, and 1 1 million tons are available but with potential land-use restrictions. Technological factors restrict 74% (3 billion tons) of the resources, and the majority of these are restricted by un- favorable stripping ratio (66% of re- sources) . Unfavorable drift thickness restricts 7% of the resources, and the size or geometry of the mining block restricts less than 1%. Land use restricts surface mining of 15% of the re- sources, and the majority (11% of the resources) is from towns. Major areas of Danville Coal are available for sur- face mining in the eastern and north- central parts of the state, but smaller surface-minable blocks are also present along the southern crop of the coal in Saline and Williamson Counties (fig. 23). Jamestown Coal Less than 1 billion tons (26%) of the original resources of Jamestown Coal are available for mining (fig. 24A), and essentially all of these available re- sources are 42 to 66 inches thick (table 6). An additional 58 million tons (less than 2%) are available but in potentially restricted areas that have a medium density of oil wells present. All of the available coal resources are minable only by underground methods and are located in the east-central part of the state (fig. 25). Technological factors re- strict mining of 62% of the resources (2.2 billion tons): the major restrictions are coal less than 42 inches thick (27%) , thin interburden between the Jamestown and overlying Danville Coal (24%), and mining block size or geom- etry (11%). Land use, primarily a high density of oil wells, restricts mining of 10% of the resources. All of the re- sources of Jamestown Coal less than 200 feet deep have an unfavorable stripping ratio. Dekoven Coal Of the 6 billion tons of original re- sources of the Dekoven Coal, only 300 million tons (5%) are available for min- ing (fig. 24B). Two-thirds of these avail- able resources are 42 to 66 inches thick, and the remaining are less than 42 inches thick (table 6) . An additional 100 million tons (1%) are available but with potential restrictions. Technologi- cal factors restrict 89% (5.3 billion tons) of the resources, and land-use factors restrict 4% (200 million tons) . Almost all of the original Dekoven Coal resources lie deep enough to be poten- tially minable by underground meth- ods. Of these resources, 200 million tons (4%) are available for under- ground mining. An additional 24 mil- lion tons are available but within areas that have a medium density of oil wells. The major technological factors that restrict underground mining of the Dekoven Coal are thin interburden be- tween the Dekoven Coal and resources in the underlying Davis Coal (55%) , coal less than 42 inches thick (25%), and size of mining block (7%). Thin bedrock and/or thick unconsolidated overburden and faults within the coal restrict a total of about 4% of the re- sources. Land use restricts 4% of the resources. Based on the current extent of mapping of the Dekoven Coal, the resources available for underground mining are limited to select areas in Hamilton and Wayne Counties in southeastern Illinois (fig. 26). Surface minable resources of Dekoven Coal are commonly mined together with the Davis seam; thus, their combined avail- ability for surface mining is addressed later in this report. Davis Coal About 4.7 billion tons (49%) of the original 9.6 billion tons of Davis Coal resources are available for mining (fig. 24C). Most of these available resources (4.5 billion tons) are 42 to 66 inches thick; 200 million tons are greater than 66 inches thick; and fewer than 100 million tons are only 28 to 42 inches thick (table 6) . An additional 500 mil- lion tons (5% of resources) are avail- able but with potential restrictions. Technological factors restrict 41% (3.9 billion tons), and land-use factors re- strict about 4% (400 million tons) . Almost all of the original Davis Coal re- sources lie deep enough to be poten- tially underground minable, and 4.6 billion tons of these underground re- sources (48%) are available for mining. An additional 500 million tons (5%) are available but within areas of potential restrictions that have a medium den- sity of oil wells or 75 to 100 feet of bed- rock overburden. Technological factors that restrict underground mining are coal less than 42 inches thick (34%) and size of mining block (3%). Thin bed- rock and/or thick unconsolidated overburden and faults within the coal restrict a total of about 4% of the re- sources. Land use restricts about 4% of the resources. As currently mapped, Davis Coal resources available for un- derground mining are located in the southeastern part of the state (fig. 27). Surface minable resources of Davis Coal are commonly mined together with the Dekoven seam; thus, their combined availability is assessed. Surface Mining of the Dekoven and Davis Coals About 202 million tons of the original Davis Coal resources lie at depths less than 200 feet, which is shallow enough to be considered for surface mining. Illinois State Geological Survey Illinois Minerals 124 3 3 Dekoven Coal Available I Available with potential restrictions Restricted or mined out A Dekoven Coal eroded or not mapped 25 Miles Figure 26 Areas of the Dekoven Coal available for underground mining. 34 Illinois Minerals 1 24 linois State Geological Survey Davis Coal Available I Available with potential restrictions Restricted or mined out N A Davis Coal eroded or not mapped 25 Miles Figure 27 Areas of the Davis Coal available tor underground mining. linois State Geological Survey linois Minerals 1 24 3 5 Dekoven and Davis Coals B Available Available with potential restrictions Restricted or mined out Dekoven and Davis Coals eroded or not mapped A 25 Miles Figure 28 Areas of the Dekoven and Davis Coals available for surface mining. 3 6 Illinois Minerals 1 24 Illinois State Geological Survey DE WITT MACON SHELBY COA NO! o o o M APPED DOUGLAS COAL MOULTRIE FAYETTE Seelyville Coal Available I Available with potential restrictions Restricted or mined out A Extent of mapping of Seelyville Coal 25 Miles Figure 29 Areas of the Seelyville Coal available for underground mining. Illinois State Geological Survey Illinois Minerals 1 24 3 7 Danville Jamestown Dekoven Davis Seelyville i 10 billions of tons Figure 30 Availability of coal resources by seam. As the Davis Coal is deeper than the Dekoven Coal, its depth is the main limiting factor when these two coals are considered together for surface mining. The Dekoven contains about 1 58 million tons of potentially surface minable resources, but when these two coals are combined, about 360 million tons of coal are potentially surface minable. The Davis Coal, which is gen- erally thicker than the Dekoven, con- tains the majority of the combined re- sources (table 7). Of the combined original resources, 266 million tons (74%) are available for surface mining. Technological factors restrict about 6% (22 million tons) of the resources. Major restrictions include unfavorable stripping ratio (3% of resources, based on depth of Davis Coal and combined thickness of both coals) and unfavor- able drift thickness (3%). A total of about 1% of the resources are re- stricted by land use and geometry or size of the mining block. Resources of the Dekoven and Davis Coals available for surface mining are located in the southern part of the state, along the crop lines of these coals in Gallatin, Saline, and Williamson Counties (fig. 28) . Seelyville Coal About 6.7 billion tons (69%) of the original resources of Seelyville Coal are available for mining (fig. 24D) . This amount reflects a 20% reduction in the total available tonnage, which repre- sents the possible amount of resource that may be unavailable because of ex- cess parting material in the Seelyville Coal. All of the available Seelyville Coal is minable only by underground meth- ods. Of these available resources, 4.8 billion tons are 42 to 66 inches thick, and 1 .9 billion tons are greater than 66 inches thick (table 6). An additional 270 million tons (about 3%) are available but in potentially restricted areas that have a medium density of oil wells present (fig. 29) . Technological factors restrict mining of 22% of the original resources. The major restrictions are partings within the coal (20% of avail- able coal) and mining-block size or ge- ometry (4% of the original resources). Land use, primarily areas with a high density of oil wells, restricts mining of 6% of the resources. All of the Seelyville Coal resources lie greater than 200 feet deep and thus are not likely to be surface mined. Conclusions The Danville, Jamestown, Dekoven, Davis, and Seelyville Coals collectively represent 48 billion tons (23%) of the state's original coal resources. A total of approximately 17 billion tons of these five seams are available for mining (fig. 30) , representing nearly 8% of the state's original resources. "Available" means that the land use and physical characteristics of the deposit (e.g., thickness, depth, in-place tonnage, and stability of bedrock overburden) are comparable with the conditions where these and other coals are currently be- ing mined in the state. Other coal may be available but with potential restric- tions that make it less desirable to mine, such as the presence of closely spaced oil wells and test holes, less stable roof strata, or close proximity to developing areas. Because of the lack of experience in underground mining of these coals in Illinois, additional geo- logic conditions may exist that restrict mining but that were not identified by this study. The 19.6 billion tons of Danville Coal resources are the third largest in the state (after the Herrin and Springfield Coals, respectively); however, only 23% of original Danville resources (4.5 bil- lion tons) are available for mining. The majority of the available Danville re- sources (4.2 billion tons) is minable by underground methods, and an addi- tional 300 million tons are available but with potential restrictions. Approxi- mately 360 million tons are available by surface mining methods. Of the total amount of available Danville Coal, ap- proximately 1 .2 billion tons have a me- dium- to low-sulfur content. Major re- strictions to underground mining of this seam are thin coal, undesirable overburden characteristics, and thin interburden between the Danville and resources in the underlying Jamestown and/or Herrin Coals. Restrictions to surface mining include high stripping ratios, thick drift cover, and land use. The Jamestown Coal resources rank eighth in the state (3.6 billion original tons), and, because of its depth, this coal must be mined underground. A total of about 900 million tons (26% of original Jamestown resources) are available for mining; 100 million of these tons are in areas with numerous oil wells. Major restrictions to mining the Jamestown are thin coal and thin interburden between the Jamestown and the resources in the overlying Danville Coal. 38 linois Minerals 1 24 Illinois State Geological Survey Of the 6 billion original ions of I )ekoven ( loal, only 300 million tons (5%) are available tor mining. Of these, 200 million tons are available by under- ground mining methods, and just over 1 00 million tons are available by sur- face mining methods, when mined in combination with the underlying Davis Coal. Major restrictions to under- ground mining of the Dekoven are thin coal and thin interburden between this seam and the Davis Coal. Restrictions to surface mining include high strip- ping ratios and thick drift cover. The 9.6 billion tons of Davis Coal re- sources are the sixth largest of all seams in the state, and 4.7 billion tons (49%) are available for mining. Of these, the vast majority (4.6 billion tons) is available for mining by under- ground methods; an additional 500 million tons are available but with po- tential restrictions. Of this available coal, only about 100 million tons are available by surface mining methods, when combined with the overlying Dekoven Coal. Major restrictions to underground mining of the Davis Coal are thin coal, undesirable overburden characteristics, and faults within the coal. As with the Dekoven, restrictions to surface mining of the Davis Coal in- clude high stripping ratios and thick drift. The 9.7 billion tons of Seelyville Coal are the fifth-largest resource in the state, and 6.7 billion tons (69% of its original resources) are available for mining. An additional 270 million tons are available but are located in areas with numerous oil wells. The Seelyville Coal is only available by underground mining methods, and major restric- tions to mining are the numerous part- ings within the coal and areas heavily drilled for oil. Technological factors cause the most significant restrictions to the availabil- ity of each of the coals in this report. For underground mining, these factors include the thickness of interburden between seams, thickness of drift and bedrock overburden, and thickness of the coal seam itself. To minimize nega- tive impacts of geologic conditions on mining costs, companies should avoid areas of thick drift and thin bedrock cover, areas with sandstone in the immediate mine roof, large areas of excessive partings in the coal, and faulted areas. For surface mining, the major techno- logical restrictions to mining the coals in this study are stripping ratio and thickness of drift. These conditions make the cost of surface mining too high to compete successfully with local underground mines or with surface- mined coal from western states in today's markets. In most parts of Illinois, land use is a relatively minor restriction to under- ground mining of these seams. The major land-use restrictions to under- ground mining are areas of closely spaced oil wells, and areas related to urban development. Land use, particu- larly a close proximity to towns, is a significant restriction to surface mining. References Cady, G.A., 1952, Minable coal reserves of Illinois: Illinois State Geological Survey, Bulletin 78, 138 p. Chou, C.-L., 1991, Distribution and forms of chlorine in Illinois Basin coals, in J. Striger and D.D. Banerjee, eds., Chlorine in coal: Amsterdam, Elsevier Science Publishers, p. 1 1-29. Chou, M.-I., J.M. Lytle, S.C. Kung, and K.K. Ho, 1999, Effects of chlorine in coal on boiler superheater/ reheater corrosion, in Preprint Papers, Ameri- can Chemical Society, Division of Fuel Chemistry, v. 44, no. 2, p. 167- 171. Chou, M.-I., J.M. Lytle, S.C. Kung, K.K. Ho, L.L. Baxter, and P.M. Goldberg, 1998, Effects of chlorine in coal on boiler corrosion, 1995-1998 pro- gram: Illinois State Geological Sur- vey, Final Report to the Illinois Coal Development Board, Illinois Clean Coal Institute, 28 p. Eggleston, J.R., M.D. Carter, and J.C. Cobb, 1990, Coal resources available for development — A methodology and pilot study: Reston, Virginia, U.S. Geological Survey, Circular 1055, 15 p. Gluskoter, 1 1. J. , and J.A.Simon, 1968, Sulfur in Illinois coals: Illinois State Geological Survey, Circular 432, 28 p. Greb, S.F., DA. Williams, and A.I ). Williamson, 1992, Geology and stratigraphy of the Western Kentucky Coal Field: Lexington, Kentucky, Kentucky Geological Survey, Bulletin 2, Series XI, 77 p., 1 plate. Haq, B.U., and EWB. Van Eysinga, 1998, Geological time table: Amsterdam, Elsevier Science B.V, 1 sheet. Harper, D., 1985, Coal mining in Vigo County, Indiana: Bloomington, Indi- ana, Indiana Geological Survey, Spe- cial Report 34, 67 p. Harper, D., 1988, Coal mining in Sullivan County, Indiana: Bloomington, Indiana, Indiana Geo- logical Survey, Special Report 43, 48 p. Harper, D., 1994, Underground mines in the Hymera Coal Member (Penn- sylvanian) of Indiana: Bloomington, Indiana, Indiana Geological Survey, Occasional Paper 62, 12 p. Jacobson, R. J., 1973, revised 2000, Depositional history of the Pennsyl- vanian rocks in Illinois: Illinois State Geological Survey, Geonote 2, 12 p. Jacobson, R.J., 1985, Coal resources of Grundy, La Salle, and Livingston Counties, Illinois: Illinois State Geo- logical Survey, Circular 536, 58 p. Jacobson, R.J. , 1 987, Stratigraphic cor- relations of the Seelyville, Dekoven, and Davis Coals of Illinois, Indiana, and western Kentucky: Illinois State Geological Survey, Circular 539, 27 p. Jacobson, R.J., 1993, Coal resources of the Dekoven and Davis Members (Carbondale Formation) in Gallatin and Saline Counties, southeastern Il- linois: Illinois State Geological Sur- vey, Circular 551, 41 p. Jacobson, R.J., and L.E.Bengal, 1981, Strippable coal resources of Illinois, Part 7 — Vermilion and Edgar Coun- ties: Illinois State Geological Survey, Circular 52 1,24 p. linois State Geological Survey linois Minerals 1 24 3 9 Jacobson R.J., C.B. Trask, C.H. Ault, D.D. Carr, H.H. Gray, W.A. Hasen- mueller, D.Williams, andA.D. Williamson, 1985, Unifying nomen- clature in the Pennsylvanian System of the Illinois Basin: Illinois State Geological Survey, Reprint Series, RPR 1985-K. (Reprinted from Trans- actions of the Illinois Academy of Science, v. 78, no. 1-2, p. 1-11, 1985.) lacobson, R.J., C.G. Treworgy, and C. Chenoweth, 1996, Availability of coal resources for mining in Illinois, Mt. Carmel Quadrangle, southeastern Illinois: Illinois State Geological Sur- vey, Mineral Note, 39 p. Monroe, S.L., and R.J. Clarkson, 1994, Pilot-scale evaluation of a high-chlorine Illinois Basin coal for effects on fireside corrosion, Final report prepared for Southern Com- pany Services, Kerr-McGee Corp., Electric Power Resarch Institute, and Illinois Clean Coal Institute, SRI-ENV-94-346R-8180, 43 p. Shaver, R.H., etal., 1986, Compendium of Paleozoic rock-unit stratigraphy in Indiana; A revision: Bloomington, Indiana, Indiana Geological Survey, Bulletin 59, 203 p., 2 plates. Smith, W.H., 1957, Strippable coal re- serves of Illinois, Part 1 — Gallatin, Hardin, Johnson, Pope, Saline, and Williamson Counties: Illinois State Geological Survey, Circular 228, 39 p. Smith, W.H., 1968, Strippable coal re- serves of Illinois, Part 6 — La Salle, Livingston, Grundy, Kankakee, Will, Putnam, and Parts of Bureau and Marshall Counties: Illinois State Geo- logical Survey, Circular 419, 29 p. Smith, W.H., and D.J. Berggren, 1963, Strippable coal reserves of Illinois, Part 5A — Fulton, Henry, Knox, Peo- ria, Stark, Tazewell, and parts of Bu- reau, Marshall, Mercer, and Warren Counties: Illinois State Geological Survey, Circular 348, 59 p. Treworgy, C.G. , 1981, The Seelyville Coal — A major unexploited seam in Illinois: Illinois State Geological Sur- vey, Illinois Mineral Notes 80, 1 1 p. Treworgy, C.G., 1999, Coal resources map and availability of coal for min- ing, Villa Grove Quadrangle, Douglas County, Illinois: Illinois State Geo- logical Survey, IGQ Villa Grove-CR, 1:24,000. Treworgy, C.G., and M.H. Bargh, 1982, Deep-minable coal resources of Illi- nois: Illinois State Geological Survey, Circular 527, 65 p. Treworgy, C.G., C.A. Chenoweth, and M.H. Bargh, 1995, Availability of coal resources for mining in Illinois: Galatia Quadrangle, Saline and Hamilton Counties, Southern Illinois: Illinois State Geological Survey, Illi- nois Minerals 1 13, 38 p. Treworgy, C.G., C.A. Chenoweth, and R.J. Jacobson, 1996a, Availability of coal resources for mining in Illinois, Newton and Princeville Quadrangles, Jasper, Peoria and Stark Counties: Il- linois State Geological Survey, Open File Series 1996-3, 47 p. Treworgy, C.G., C.A. Chenoweth, and M.A. Justice, 1996b, Availability of coal resources for mining in Illinois, Atwater, Collinsville and Nokomis Quadrangles, Christian, Macoupin, Madison, Montgomery and St. Clair Counties: Illinois State Geological Survey, Open File Series 1996-2, 33 p. Treworgy, C.G., C.A. Chenoweth, J.L. McBeth, and C.R Korose, 1997a, Availability of coal resources for mining in Illinois, Augusta, Kewanee North, Mascoutah, Pinckneyville and Roodhouse East Quadrangles, Adams, Brown, Greene, Henry, Perry, Schuyler and St. Clair Coun- ties: Illinois State Geological Survey, Open File Series 1997-10, 72 p. Treworgy, C.G., G.K. Coats, and M.H. Bargh, 1994, Availability of coal re- sources for mining in Illinois, Middletown Quadrangle, Central Illi- nois: Illinois State Geological Survey, Circular 554, 48 p. Treworgy, C.G., and R.J. Jacobson, 1986, Paleoenvironments and distri- bution of low-sulfur coal in Illinois, in A.T. Cross, ed., Economic geol- ogy — Coal, oil and gas, Compte Rendu, v. 4, Ninth International Con- gress of Carboniferous Stratigraphy and Geology, Washington and Champaign-Urbana, May 1979: Southern Illinois University Press, Carbondale, p. 349-359. Treworgy, C.G., C.R Korose, C.A. Chenoweth, andD.L. North, 1999a, Availability of the Springfield Coal for mining in Illinois: Illinois State Geo- logical Survey, Illinois Minerals 118, 43 p. Treworgy, C.G., C.R Korose, and C.L. Wiscombe, 2000, Availability of the Herrin Coal for mining in Illinois: Illi- nois State Geological Survey, Illinois Minerals 120, 54 p. Treworgy, C.G., J.L. McBeth, C.A. Chenoweth, C.R Korose, and D.L. North, 1998, Availability of coal re- sources for mining in Illinois, Albion South, Peoria West, Snyder- West Union, Springerton andTallula Quadrangles, Clark, Edwards, Hamilton, Menard, Peoria, Sangamon and White Counties: Illi- nois State Geological Survey, Open File Series 1998- 1,92 p. Treworgy, C.G., and D.L. North, 1999, Availability of coal resources for mining in Illinois, Shawneetown Quadrangle, Gallatin County: Illinois State Geological Survey, Open File Series 1999-7, 35 p. Treworgy, C.G., D.L. North, C.L. Conolly, and L. Furer, 1999b, Coal re- sources map and availability of coal for mining, Vincennes Quadrangle, Lawrence County, Illinois and Knox County, Indiana: Illinois State Geo- logical Survey, IGQ Vincennes-CR, 1:24,000. Treworgy, C.G., E.I. Prussen, MA. Jus- tice, C.A. Chenoweth, M.H. Bargh, R.J. Jacobson, and H.H. Damberger, 1997b, Illinois coal reserve assess- ment and database development — Final report: Illinois State Geological Survey, Open File Series 1997-4, 105 p. Wier, C. E., 1973, Coal resources of In- diana: Bloomington, Indiana, Indiana Geological Survey, Bulletin 42-1, 40 p. Wood, G.W., Jr., T.M. Kehn, M.D. Carter, and WC. Culbertson, 1983, Coal re- source classification system of the U.S. Geological Survey: Reston, Vir- ginia, U.S. Geological Survey, Circu- lar 89 1,65 p. 40 Illinois Minerals 1 24 Illinois State Geological Survey Appendix 1 Remaining resources by county and availability by mining method (millions of tons). Remaining resources Total available Available by mining method 1 Surface Underground Danville Coal Bureau 422 Champaign 162 Christian 63 Clark 1,611 Coles 1,140 Crawford 1,213 Cumberland 894 Douglas 179 Edgar 1,609 Effingham 1,202 Fayette 307 Fulton 57 Henry 56 Jasper 1,243 Knox 20 Lasalle 563 Lawrence 1,129 Livingston 1,996 McLean 1,704 Macoupin 16 Marshall 362 Montgomery 53 Peoria 276 Putnam 218 Richland 652 Saline 69 Shelby 130 Stark 56 Tazewell 5 Vermilion 1,918 Williamson 56 Woodford 39 Total 19,420 Jamestown Coal Clark 684 Crawford 1,500 Lawrence 1,399 Total 3,583 Dekoven Coal Edwards 76 Franklin 379 Gallatin 950 Hamilton 738 Saline 723 Wabash 107 Wayne 748 White 1,513 Williamson 672 6 29 784 285 176 530 4,512 109 419 403 931 Total 5,908 140 37 331 20 366 19 19 74 - 61 61 29 784 285 176 510 15 15 - 15 15 - 5 5 . 10 10 - 410 - 410 727 75 659 515 - 515 15 15 - 53 53 - 5 5 - 16 16 - 913 128 808 3 3 - 4,175 109 419 403 931 37 117 74 140 213 linois State Geological Survey linois Minerals 1 24 4 1 Available by mining method Remaining resources Total available Surface Underground Davis Coal Edwards 672 520 - 520 Franklin 566 19 - 19 Gallatin 1,266 907 29 892 Hamilton 1,117 308 - 308 Saline 1,369 1,109 74 1,046 Wabash 788 484 - 484 Wayne 1,363 675 - 675 White 1,946 617 - 617 Williamson 480 125 45 81 Total 9,568 4,764 148 4,642 Seelyville Coal Clark 1,064 737 - 737 Clay 34 22 - 22 Coles 748 540 - 540 Crawford 2,199 1,206 - 1,206 Cumberland 1,335 1,007 - 1,007 Edgar 877 674 - 674 Effingham 376 288 - 288 Jasper 2,148 1,621 - 1,621 Lawrence 554 308 - 308 Richland 132 104 - 104 Shelby 207 164 - 164 Vermilion 29 - - - Total 9,703 6,671 - 6,671 Surface and underground availability do not add to the total availability because coal that lies between 75 and 200 feet deep is included in both categories. 42 Illinois Minerals 1 24 linois State Geological Survey Appendix 2 Source maps lor coal resources. County Seam Source (ISGS publications) Map year Scale (x1,000) Bureau Danville Cady 1952, Smith and Berggren 1963, Smith 1968 1950 125 Champaign Danville Treworgy and Bargh 1982 1978' 62.5 Christian Danville Cady 1952 1950 62.5 Clark Danville Treworgy et al. 1997b 1996 50 Clark Jamestown Treworgy et al. 1997b 1996 50 Clark Seelyville Treworgy 1981 1978 62.5 Clay Seelyville Treworgy 1981 1978 62.5 Coles Danville Treworgy et al. 1997b 1996 50 Coles Seelyville Treworgy 1981 1978 62.5 Crawford Danville Treworgy et al. 1997b 1996 50 Crawford Jamestown Treworgy et al. 1997b 1996 50 Crawford Seelyville Treworgy 1981 1978 62.5 Cumberland Danville Treworgy et al. 1997b 1996 50 Cumberland Seelyville Treworgy 1981 1981 62.5 Douglas Danville This study 2001 50 Edgar Danville Treworgy et al. 1997b 1996 50 Edgar Seelyville Treworgy 1981 1981 62.5 Edwards Dekoven This study 2001 50 Edwards Davis This study 2001 50 Effingham Danville Treworgy et al. 1997b 1996 50 Effingham Seelyville Treworgy 1981 1981 62.5 Fayette Danville Cady 1952 1950 62.5 Franklin Dekoven Cady 1952 1950 62.5 Franklin Davis Cady 1952 1950 62.5 Fulton Danville Smith and Berggren 1963 1963 125 Gallatin Dekoven Jacobson 1993 1993 62.5 Gallatin Davis Jacobson 1993 1993 62.5 Hamilton Dekoven Cady 1952 1950 1 62.5 Hamilton Davis Cady 1952 1950 1 62.5 Henry Danville Smith and Berggren 1963 1963 125 Jasper Danville Treworgy et al. 1997b 1996 50 Jasper Seelyville Treworgy 1981 1981 62.5 Knox Danville Smith and Berggren 1963, 1963' 125 La Salle Danville Jacobson 1985 1985' 62.5 Lawrence Danville Treworgy et al. 1997b 1996 50 Lawrence Jamestown Treworgy et al. 1997b 1996 50 Lawrence Seelyville Treworgy 1981 1981 62.5 Livingston Danville Jacobson 1985 1985 1 62.5 McLean Danville This study 2001 50 Macoupin Danville Cady1952 1950 62.5 Marshall Danville Cady 1952, Smith and Berggren 1963 1950 62.5 Montgomery Danville Cady 1952 1950 62.5 Peoria Danville Smith and Berggren 1963 1963 125 Putman Danville Cady 1952 1950 62.5 Richland Danville Work map by C. Treworgy 1978 62.5 Richland Seelyville Treworgy 1981 1981 62.5 Saline Danville Smith 1957 1957 125 Saline Dekoven Smith 1957, Jacobson 1993 1957 125 Saline Davis Smith 1957, Jacobson 1993 1957 125 Shelby Danville Cady 1952 1950 62.5 Shelby Seelyville Treworgy 1981 1981 62.5 Stark Danville Smith and Berggren 1963 1963 125 Tazewell Danville Smith and Berggren 1963 1963 125 Vermilion Danville Jacobson and Bengal 1981 1981' 62.5 Wabash Dekoven This study 2001 50 linois State Geological Survey linois Minerals 1 24 4 3 County Seam Source (ISGS publications) Map year Scale (x1,000) Wabash Davis This study Wayne Dekoven This study Wayne Davis This study White Dekoven Cady 1952 White Davis Cady 1952 Williamson Danville Smith 1957 Williamson Dekoven Cady 1952, Smith 1957 Williamson Davis Cady 1952, Smith 1957 Woodford Danville Cady 1952 2001 50 2001 50 2001 50 1950 1 62.5 1950 1 62.5 1957 125 1950 125 1950 125 1950 62.5 Minor revisions made for this report. 44 linois Minerals 1 24 Illinois State Geological Survey J3 CD I—*- c — * w CD i o CD — * CD J2 C CD C/) ^^- CD Q. 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