UNITED STATES MINERAL RESOURCES 



COAL 



By Paul Averitt 



CONTENTS 



Page 



Abstract of conclusions 133 



Introduction 133 



Environment of coal accumulation 134 



Rank of coal 134 



Grade of coal 134 



Sulfur 135 



Research on removal of sulfur 135 



Minor elements in coal 136 



United States coal resources 136 



Identified resources 138 



Distribution by selected categories 138 



Stripping coal resources 139 



Hypothetical resources 139 



Speculative resources 140 



World coal resources 140 



References cited 140 



15. 



16. 



17. 



26. 



FIGURES 



Graph showing comparison on moist, mineral- 

 matter-free basis of heat values and proxi- 

 mate analyses of coal of different ranks — 



Graph showing approximate percentage distri- 

 bution of original identified U.S. coal re- 

 sources by major resource categories 



Graph showing probable distribution of total 

 estimated U.S. coal resources according to 

 thickness of overburden 



TABLES 



Distribution of identified United States coal re- 

 sources according to rank and sulfur content- 

 Total estimated remaining coal resources of 



the United States, January 1, 1972 



Estimated total original coal resources of the 

 world, by continents 



135 



138 



139 



140 



ABSTRACT OF CONCLUSIONS 



The estimated coal resources of the United States remain- 

 ing in the ground as of January 1, 1972, totaled 3,224 billion 

 tons. Of this large total, 1,581 billion tons, or 49 percent, is 

 classed as identified, and 1,643 billion tons, or 51 percent, is 

 classed as hypothetical. 



Stripping coal resources remaining in the ground as of 

 January 1, 1968, totaled 118 billion tons, or about 7.5 percent 

 of the identified resources. 



World coal resources are estimated to total 16,830 billion 

 tons, of which 9,500 billion tons is classed as identified, and 

 7,330 billion tons is classed as hypothetical. The United 

 States contains about one-fifth of estimated total world re- 

 sources. 



On a uniform Btu basis, U.S. coal resources are larger 

 than the combined domestic resources of petroleum, natural 

 gas, oil shale, and bituminous sandstone. The prolonged fu- 

 ture need for energy in ever-increasing quantities, and the 

 prospect of decreasing availability of and increased prices 

 for petroleum and natural gas, have focused very sharp at- 

 tention on coal as an alternative source of synthetic gas, 

 liquid fuels, and lubricants. 



INTRODUCTION 



Coal is widespread and abundant in the United 

 States. Coal-bearing rocks underlie about 13 percent 

 of the land area of the 50 States, and are present 

 in varying amounts in parts of 37 States (Trum- 

 bull, 1960; Barnes, 1961). The ready availability of 

 coal has contributed substantially to the growth 

 and industrial development of the nation. 



On any basis of analysis, U.S. resources of coal 

 are larger than the combined resources of petroleum, 

 natural gas, oil shale, and bituminous sandstone, 

 but use of coal lags behind use of both petroleum 

 and natural gas because these two fuels are cleaner 

 to burn and easier to handle. In spite of this handi- 

 cap, annual coal production in the United States 

 ranges typically from 500 to 600 million tons. About 

 10 percent of the annual production is exported, 

 primarily to Japan, Canada, and western Europe. 



Of coal consumed annually in the United States, 

 about 62 percent is used in the production of elec- 



U.S. GEOL. SURVEY PROF. PAPER 820 



133 



