Cal Poly Geology Club Death Valley Field Trip – 2004

GeologyThe mine workings lie entirely within the Proterozoic Noonday Dolomite., amassive, highly weathered, cream-colored dolomite. Rusty weathering sand grains,especially in the upper part, locally makes cross bedding evident. Fracturing andbrecciation is common, forming fissures for ore deposition. The mines lie above theunconformable contact between a granite gneiss and the Noonday formation. TheProterozoic Johnnie formation lies in conformable contact above the Noonday. Thiscontact is well exposed near the Gunsite mine, northwest of the War Eagle mine. The orelies within a series of steeply dipping (sometimes vertical) north-south trending faults.The ore consists chiefly of lead carbonates with some unoxidized galena. Argentiferousgalena was the primary ore mineral, but oxidation has produced cerrusite and anglesite.In 1951 the War Eagle was the most important producing mine of the Shoshone Minesgroup. Lateral workings of the War Eagle are quite extensive. This field trip stop isactually the “back” side of the workings. These workings continue through to the otherside of the hill we are facing, however this connection has recently collapsed and you areno longer able to walk through the mine workings to the “front” side of the War Eagle.The road to the “front” side of the mine is nearly undriveable, thereby making the “back”side of the mine much more accessible.SummaryThe history of the Resting Springs Mines was sporadic and not as “colorful” asother mining districts in the area. However, in terms of lead and silver production it wasconsidered one of the three largest lead producers within the state of California. Betweenthe discovery of the district in 1876 to its final days of operations in 1957 the RestingSprings Mining District was responsible for production of more than $7,000,000 worth oflead-silver ores. Today, all that is left are mine workings and memories to be explored byrockhounds, mineral collectors and history aficionados.