The Jefferson Mountain area, located at the eastern end of
the Centennial Mountains in Fremont County, Idaho and Beaverhead
County, Montana, is approximately 42 square miles in size. The
area contains exposed metamorphic, sedimentary, and volcanic
rocks ranging in age from Precambrian to Tertiary. Approximately
2,500 feet of Paleozoic and...
The Pennsylvanian rocks in south-central Idaho and adjacent areas consist of three main facies: a platform facies, a shelf facies, and a marginal basin facies. The platform facies is represented by the Amsden, Quadrant, and Tensleep Formations, in southwestern Montana and western Wyoming, and contain Middle and probably Lower Pennsylvanian...
The Permian rocks near Quinn River Crossing, Humboldt County,
Nevada, crop out as a north-trending block-faulted ridge and consist
of more than 2600 feet of middle Permian fossiliferous limestone.
About 1000 feet of unfossiliferous cherty shales, sandstones, and
conglomerates are associated with the limestone and are assumed also
to be...
The thesis area consists of 42 square miles located
in Madison and Gallatin counties, Montana, in the southern
part of the Madison Range. The strata exposed in the
area range in age from Precambrian to Quaternary and have
an aggregate thickness of more than 7,600 feet.
The Paleozoic rocks, about...
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...
The Cedar Creek area, consisting of about 30 square miles, is
located on the west flank of the central Madison Range in Madison
County, Montana.
The rocks of the area include carbonates, sandstones, mudstones,
cherts, phosphorite, metamorphic rocks, intrusive igneous
rocks, and unconsolidated sediments and have been divided into 16...