Field Trip Day Two: Magmatic and Hydrothermal Features of the Yerington Batholith with Emphasis on the Porphyry Cu(Mo) Deposit in the Ann-Mason Area
John H. Dilles, John Proffett, Marco T. Einaudi, 2000. "Field Trip Day Two: Magmatic and Hydrothermal Features of the Yerington Batholith with Emphasis on the Porphyry Cu(Mo) Deposit in the Ann-Mason Area", Part I. Contrasting Styles of Intrusion-Associated Hydrothermal Systems: Part II. Geology & Gold Deposits of the Getchell Region, John H. Dilles, Mark D. Barton, David A. Johnson, John M. Proffett, Marco T. Einaudi, Elizabeth Jones Crafford
Download citation file:
THE PURPOSE of this one-day tour is to examine time-space relationships of hydrothermal alteration features and associated porphyry Cu(Mo) and Cu-Fe-Au mineralization, and the relationship of these hydrothermal features to the magmatic history of the Yerington batholith. The batholith exposures we will examine represent an intermediate between the Birch Creek and Buena Vista end members. At Yerington, mag-matic brines were essential to formation of porphyry Cu(Mo) deposits, but at the same time a huge hydrothermal system driven by the batholithic heat was dominated by sedimentary brines and produced Fe oxide-Cu-Au ores distal to the porphyry centers. It will be advantageous to read the papers in this guidebook by Dilles and Proffett (1995) and Dilles et al. (2000) that provide summaries of the magmatic and hy-drothermal histories, respectively, of the Yerington batholith.
The descriptions and maps below are lengthy because of the complexity of the exposures and large size of the intrusion-related hydrothermal system. This tour can be accomplished in a leisurely fashion in two days, but can be done in one. There are two short hikes and nine roadside stops.