Link to USGS Home Page

Coal Resource Classification System of the U.S. Geological Survey

By Gordon H. Wood, Jr., Thomas M. Kehn, M. Devereux Carter, and William C. Culbertson

GEOLOGICAL SURVEY CIRCULAR 891


Table 3. - Summary of coal resource criteria

  Depth1
Feet (Meters)
Thickness1
Inches (Centimeters)
Identified and undiscovered resources:        
Anthracite and bituminous coal 6,000 (1,800) 14 (35)
Subbituminous coal and lignite 6,000 (1,800) 30 (75)
         
Reserve base and inferred reserve base:        
Anthracite and bituminous coal 1,000 (300) 28 (70)
Subbituminous coal 1,000 (300) 60 (150)
Lignite 500 (150) 60 (150)
         
Reserves2, marginal reserves, and inferred reserves2:        
(Criteria same as reserve base and inferred reserved base but with factors based on engineering and economic analysis applied.)        
         
Subeconomic resources:        
Anthracite and bituminous coal 0-1,000 (300) 14 (35) -28 (70)
  1,000(300)-6,000 (1,800) 14(35)  
Subbituminous coal 0-1,000 (300) 30 (75) -60(150)
  1,000 (300)-6,000 (1,800) 30(75)  
Lignite 0-500 (150) 30 (75) -60 (150)
  500 (150)-6,000 (1,800) 30(75)  

1The metric thicknesses shown in parentheses are not exact equivalents of the thicknesses shown in feet; for convenience, they have been rounded to the amounts shown.
2Includes some beds that are thinner and (or) deeper than the general criteria permit, but that are being mined currently.

PREVIOUS   NEXT

[ Contents | CD Contents | Eastern Energy Home ]


Created by the EERT WWW Staff.

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http:// pubs.usgs.gov /circ/c891/table3.htm
Page Contact: Energy Program Inquiries
Website Assistance: USGS Publications Team
Last modified: Wednesday, 23-Nov-2016 12:28:14 EST