Mammoth District, Pinal Co., Arizona, USA

This district is located in T8S, R16E, and centers around the Mammoth-St. Anthony mine (Tiger), about 3 miles SW of the town of Mammoth. It is sometimes considered part of the Old Hat District. This is principally a gold mining district; however, much lead was mined. During WWII the Mammoth-St. Anthony was worked for vanadium and molybdenum as well. The total production was about $3 million, mostly in gold.

This area is at about 3,200 feet of altitude. The host rock is a coarse granite (the Oracle Granite), presumably of Pre-Cambrian age; Mesozoic or Tertiary breccia & conglomerate, largely of andesitic to dacitic material; rhyolite, in part at least intrusive, probably of Tertiary age; and Pliocene Gila Conglomerate. All of these are rather intensely faulted.

Veins in the District occur within shear zones which strike WNW-ward & dip steeply SW-ward. Gangue consists of brecciated country rock, cemented & replaced by quartz and calcite together with some barite and fluorite.

References:
Wilson, E.D., et al (1934), Arizona Bureau of Mines Bull. 137: 170-171.