UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY
SUMMARY OF THE GEOLOGY, MINERAL RESOURCES, LANDSCAPE GEOCHEMISTRY, AND ENGINEERING GEOLOGIC CHARACTERISTICS OF THE NORTHERN POWDER RIVER COAL REGION, MONTANA
PART A. Geology and mineral resources by W. J. Mapel and V. E. Swanson
PART B.--Lands cape geochemistry by J. 0. Connor
PART C.--Engineering geologic characteristics by F. W. Osterwald, compiler \ A. F. Chleborad, C. R. Dunrud, R. A. Farrow, T. C. Nichols, Jr., E. E. McGregor, C. H. Miller, J. Odum, H. W. Olsen, F. W. Osterwald, W. Z. Savage, and W. K. Smith
OPEN-FILE REPORT 77-292 1977
This report is preliminary and has not been edited or reviewed for conformity with U.S. Geological Survey standards and nomenclature. CONTENTS Page Part A. Geology and mineral resources- . ._-- __... 1 Introduction------_-__-.__. _- 1 Geographic features------. 1 Sources of information------.-- ..-._-.___ .... 4 Conversion of metric units------___.-___. -._ 4 Status of coal studies-- -- -. -- _- --. 4 Geologic setting------5 Rock units- __._--_ .. -_..__ _ 5 Hell Creek Formation------9 Fort Union Formation------... 9 Wasatch Formation------._ _. __-_.__.._.. 13 Terrace gravels ------_._ 14 Valley-fill deposits 14 Structural features------_.._ - ._._ 15 Folds ---- - _--._ __-_. _- -__ . .-_. 15 r au I L.S- _._._ .__-_. -__---..__.__.----._-__._... ID Coal deposits _- _ _ -- ___ - _. .__ 17 Coal in the lower part of the Fort Union Formation------17 Coal in the Tongue River Member of the Fort Union Formation---- 21 Rosebud and associated coal beds------21 Knobloch coal bed- - -- _-__. .__...._ 22 Sawyer coal bed------22 Brewster-Arnold and Cache coal beds -.--__ 22 Wall coal bed 23 Canyon coal bed------23 Dietz 2 and 1 coal beds------__-_ - _._- 23 Anderson coal bed - 24 Roland coal bed 24 Coal resources------._---. _-_- _-_-. '24 Coal resources in thick, accessible deposits ------24 Coal production-- - _.._.. __ ...... 26 Coal quality and composition-- --. ------26 Col strip area------30 Ashland area------35 Decker area---- _ . ___ 38 CONTENTS--continued