Bruce Mine (Bruce deposit; Old Dick Mine), Bagdad, Eureka Mining District, Yavapai County, Arizona, USAi

Regional Level Types
Bruce Mine (Bruce deposit; Old Dick Mine)	Mine
Bagdad	- not defined -
Eureka Mining District	Mining District
Yavapai County	County
Arizona	State
USA	Country

A former underground Zn-Cu-Ag-Au-Pb-As-Co-Cd mine located 2¾ miles SSW of Bagdad and 1½ miles south of the Copper King Mine. The Old Dick patented claim was located in 1882 by William Waters, who sold it to John Lawler 9 years later. Lawler obtained a patent for it in 1892. Purchased by the Goodwin Mining Co. in 1947. S.R. Hullinger and F.G. McFarland purchased it in October, 1950; and, sold it to the Manhattan Consolidated Mines Development Co. in October, 1951. Rediscovered 1957 by the Cyprus Bruce Copper Zinc Co. Produced until 1966, then produced 1968-1977. NOTE: Alternate coordinates provided: 34°32'42"N, 113°13'15"

Mineralization is a massive sulfide deposit (Precambrian, volcanogenic) with lens-shaped and stratiform ore bodies hosted in the Brindle Formation and the Dick Rhyolite. Ore control was stratigraphy, folding, and igneous activity. Alteration included chloritization and pyritization.


One of two known examples of massive-sulfide replacement deposits in the Bagdad area. The sulfides have replaced rocks of the Bridle formation near a mass of Dick rhyolite. The ore occurs in the Yavapai schist which consists of chlorite schist and amphibolite derived from lava flows and tuffs. The meta-volcanics have been silicified and sericitized in zones adjacent to the metarhyolite and metadiabase. However, alteration is post-metadiabase for it is locally sericitized and silicified.

The ore zone is west of the Dick rhyolite and confined to foliated lava flows of the Bridle formation. The orebodies are massive-sulfide lenses that strike north, rake to the south at an angle of 35º, and range in dip from 45º to 90º in a westerly direction. The maximum width of any lens is about 35 feet, thinning toward the ends, and the maximum length is about 300 feet.

The ore lenses consist of resinous yellowish-brown and black sphalerite. Pyrite is concentrated in irregularly spaced, narrow bands 1/16 to ¼ inch wide that give the sulfides a linear structure. Even where banding is dominant, crystals of pyrite, some quite large and apparently corroded, are disseminated throughout the massive sphalerite and the pyritic bands are by no means monomineralic. Chalcopyrite occurs in minute stringers and also as wide layers that cut the massive sphalerite or follow the edge of pyrite bands. Galena forms local pods in the ore lenses. Conspicuous steel-gray, euhedral arsenopyrite crystals as much as ¼ inch in length are disseminated through the massive sulfides. These are a cobaltian variety of arsenopyrite. Minute veinlets of sphalerite cut the broken crystals of arsenopyrite. Some gold and silver are present.

Area structures include massive sulfide lenses that parallel foliation and bedding. The foliation in the Precambrian metavolcanic rocks trends N20E to N30E.

Workings include surface cuts, 2 old shafts at 50 and 67 feet deep, and an adit level. Ultimately shaft No. 2 was sunk and there were 5 levels (adit, 50, 100, 150, & 225). A vertical winze 68 feet deep from the adit level (No. 1 winze). An upper adit was begun in 1944 but abandoned when massive sphalerite was encountered. Production from 1943 - 1951 was 228 oz. Au, 22,563 oz. Ag, 1,791,055 pounds Cu, 358,840 pounds Pb, and 13,661,018 pounds Zn.

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