TYPE SECTIONS AND STRATIGRAPHY OF THE MEMBERS OF THE BLACKLEAF AND MARIAS RIVER FORMATIONS (CRETACEOUS) OF THE SWEETGRASS ARCH, MONTANA: PROFESSIONAL PAPER 974. W. A. Cobban, R. W. Lemke, C. E. Erdmann, E K. Maughan.

TYPE SECTIONS AND STRATIGRAPHY OF THE MEMBERS OF THE BLACKLEAF AND MARIAS RIVER FORMATIONS (CRETACEOUS) OF THE SWEETGRASS ARCH, MONTANA: PROFESSIONAL PAPER 974

Washington, DC: United States Geological Survey/USGS/Government Printing Office/GPO, 1976. Softcover. Item #45619

A report of a formal subdivision and age assignments of a classic Cretaceous area. 66 pages with map, photographs, tables, sections, index and references. Bound in original gray stiff paper covers printed in black. Government stamp on the front cover. A very good plus copy.

Price: $20.00