Copper Hill Mine (Copper Hill group; Patented claims MS 4452), Copper Basin Mining District, Sierra Prieta Mountains, Yavapai County, Arizona, USAi

Regional Level Types
Copper Hill Mine (Copper Hill group; Patented claims MS 4452)	Mine
Copper Basin Mining District	Mining District
Sierra Prieta Mountains	Mountain Range
Yavapai County	County
Arizona	State
USA	Country

A former underground Cu-Au-Ag-Pb-Zn-Mo mine located on 8 claims, near the center of sec. 20, T.13N., R.3W. (Wilhoit 7.5 minute topo map). Owned by Schemmer and J.E. Erickson, and was under lease to the Copper Basin Molybdenum Co. Produced 1906-1968.

Mineralization is a 300 foot diameter breccia pipe with a pipe-like or vertical cylindrical ore body. It intrudes the prevailing rock, a deeply weathered, coarse-grained, Proterozoic hornblende-quartz diorite intruded by fine-grained biotite-quartz diorite. Aplite dikes are numerous near Quartz Hill and Cross Hill. Rhyolite dikes and plugs intrude the coarse-grained quartz diorite north of Copper Hill, and south of this hill a quartz diorite porphyry dike, 30 to 50 feet wide, intrudes both the coarse- and fine-grained quartz diorite.

Both facies of quartz diorite locally have been brecciated, sericitized, and silicified. The alteration process has produced distinct zones, circular to elliptical in outline, some of which are breccia pipes. These zones are more resistant to erosion, and they form the summit areas of small hills.

The breccia in the altered hornblende-quartz diorite area is cut by low-dipping quartz veins that contain small amounts of pyrite, chalcopyrite and molybdenite. Steeply dipping quartz seams cut the breccia and the low-dipping quartz veins, but the displacement is small. Chalcopyrite and molybdenite are more common in the steeply-dipping quartz seams and in vein quartz that cements breccia fragments. Molybdenite occurs in finely-divided veinlets cutting quartz or at the margin of the veins, whereas chalcopyrite is disseminated in the quartz. Seams of brilliant yellow ferrimolybdite occur in the upper workings.

Workings feature a main shaft 300 feet deep. Underground workings include drifts, crosscuts, an old shaft, an adit, and a winze. Much of the underground development was done in 1906. Additional development work was done in 1917-18. Production of Mo ore was some 1,800 tons (1916-1918)

Other Regions, Features and Areas containing this locality

References