Record Details
Structure and stratigraphy of the Sheep Mountain area, Centennial Range, Montana-Idaho
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Structure and stratigraphy of the Sheep Mountain area, Centennial Range, Montana-Idaho |
| Names |
Moran, John Lee
(creator) Oles, Keith (advisor) Bostwick, David (advisor) |
| Date Issued | 1970-06-11 (iso8601) |
| Note | Graduation date: 1971 |
| Abstract | The thesis area includes 44 square miles of the Centennial Range in Beaverhead County, Montana, and Clark County, Idaho. The rocks exposed in the area range in age from Precambrian to Recent and have been divided into 23 mapped units. Pre-Belt metamorphic basement rocks are overlain unconformably by 3,433 feet of Paleozoic strata included in eleven formations. These formations represent all of the periods of the Paleozoic except the Ordovician and Silurian. Nine formations represent all the periods of the Mesozoic and total approximately 3,127 feet in thickness. Cenozoic units present in the area are basalts and rhyolites, landslide debris, glacial deposits, and alluvium. The major structure of the thesis area is a fault block that is the result of uplifting and tilting of the east-west trending Centennial Range during the downwarp of the Snake River Plain in late Pliocene and Pleistocene time. No stratigraphic or structural conditions in the thesis area are favorable for the accumulation and entrapment of oil and gas. Phosphorite has been mined from the Phosphoria Formation in the area. |
| Genre | Thesis/Dissertation |
| Topic | Geology, Stratigraphic |
| Identifier | http://hdl.handle.net/1957/46346 |
