Aug 31, 1977
Open File Report
… Cretaceous Clearwater Formation (shale), the Grand Rapids Formation …
Nov 18, 2008
Data
… coal, shaly-coal and coaly-shale), formation tops and …
Dec 31, 1982
Open File Report
… Barite, Bentonite, Clay and Shale, Coal, Copper, Coquina, …