Composition and properties of the Pierre Shale and equivalent rocks, northern Great Plains region
The Pierre Shale and equivalent rocks of Late Cretaceous age consist in the east-central Dakotas of several hundred feet of offshore-marine shale and minor…
Public-domain full text preserved in the Mountain Man Mining Library. Original source: pubs.usgs.gov.
Composition and properties of the Pierre Shale and equivalent rocks, northern Great Plains region Author: Schultz, Leonard Gene, Tourtelot, H. A., Gill, J. R., Boerngen, J.G. Year: 1980 Category: Report The Pierre Shale and equivalent rocks of Late Cretaceous age consist in the east-central Dakotas of several hundred feet of offshore-marine shale and minor marl; in west-central Montana near the sediment source the equivalents of the Pierre Shale consist of several thousand feet of volcanic-rich and mostly nonmarine sediments; and in the area between, both types of rock are separated by tongues of nearshore-marine siltstone and sandstone that mark three major transgressions of the sea across the area. The major-, minor-, and trace-element composition was determined for 226 samples of these roc Tags: usgs, bentonite clay deposits Source: ://pubs.usgs.gov/pp/1064b/plate-1.pdf