About This Item
Share This Item
Interpretation of 1,200 geophysical logs in the northern Powder River basin, Montana, reveals the paleodrainages influencing coal deposition during the deposition of the Tongue River member (Paleocene, Fort Union Formation). Four channels with associated crevasse splay deposits are recognized: (1) an east-west "Rosebud" drainage near Colstrip, (2) a north-south "Wall" channel near Birney, (3) a north-south "Dietz" drainage near Tongue River Reservoir, and (4) a north-south "Anderson" channel in the vicinity of Moorhead. These channels support the concept of a major northeast-flowing drainage system during deposition of the Tongue River Member. Identification of these channels serves as a guide to future coal exploration.
End_of_Article - Last_Page 1340------------