The Calcite Veins of the Livingston Formation

An interesting group of calcite veins occur near Livingston Montana in a zone about eight miles wide and forty miles long in the edge of the Plains region of Montana in front of the Main ranges. The zone extends from the Boulder River south of Big Timber, through Springdale and Hunters Hot Springs, to Potter's Basin just north of Wilsall in Park County. The group of veins is particularly interesting because they cut relatively flat lying strata, suggest a structural relation­ship to one another, and they are nearly pure calcite. The present investigation was to determine the position of the calcite veins by plotting them on a base map of the district. In addition, it was planned to determine the mineralogy end origin of the veins and their structural and stratigraphical relationship to the rocks of the Livingston formation which they cut.

A Report of the Geology of the Golden Sunlight Mining District

This paper is a report of a geological survey made of an area of approximately fifty square miles lying Northeast of Whitehall, Montana, in the region of the Golden Sun­light Mine. The survey was made by a field party consisting of twenty-three members of the senior class of the Montana School of Mines.

The Fort Union Formation of Montana and Adjacent Areas

The Fort Union formation is one of the most import­ant and best known geologic formations of the northern Great Plains, and is found lying almost horizontal at the surface over large areas in this region.

The Geology and Ore Deposits of the Ermont Mines

The Ermont Mines are located sixteen miles northwest of Dillon, Montana, in section 35 of T.6S., R.11W. This is in the central part of Beaverhead County. They are considered to be in the Argenta min­ing district, the town of Argenta lying three miles to the northeast.

The Livingston Formation of the South Boulder Area

The Livingston formation is a thick succession of late Cretaceous lava flows, tuffs, and bedded water-laid volcanic detritus 200 miles long and 100 miles wide lying along the eastern margin of the Rocky Mountains in western Montana from Augusta to Yellowstone Park. It differs markedly within short distances in lithologic character and sequences, and the total thickness may exceed one mile in some places.