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.

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.