Joint Planes in the Rhyolites of the Butte District, Montana

The problem herein discussed deals with the pointing planes found in the area of rhyolite located in the northwestern portion of the Butte District. The question to be determined was whether or not the pointing planes in the rhyolites could be class­ified with the Butte Ore fissure systems.

A Microscopic Study of some Volcanic Rocks in the Vicinity of Butte

The rhyolite rocks in the vicinity of Big Butte present a very interesting, though complicated study. It seems that no extensive or conclusive work has ever been done upon these extrusives. I have found that the rhyolites present a very interesting problem, especially microscopically, and that no doubt an intensive study along these lines will solve the problems concerning age relations of different flows and origin of the magma that produced the material for emanations.

Geology of the Tuxedo Mining District

The Tuxedo mining district lies fifteen miles west of Butte on the south east end of Deer Lodge valley. Prospecting and mining has been carried on in this district for about 20 years. As a result many pits have been dug, several adits have been driven, and two or three shallow shafts have been sunk.