Crosby mine, Nightingale Mining District, Washoe County, Nevada, USAi

Regional Level Types
Crosby mine	Mine
Nightingale Mining District	Mining District
Washoe County	County
Nevada	State
USA	Country

Structure: Faults Which Border Tactite Bodies

Alteration: Silicification

Commodity: Possible source of au, ag, cu and bi in addition to w.

Deposit: Main tactite zone at contact of calcareous sediments with granitic intrusives. A late stage plug-shaped pegmatite body associated with felsic dikes forms a dominant feature along the ridge where it crops outeast of the main tactite zone. The tactite zone was sampled (sample 2889) on the west side of the mine in a zone which included epidote and tungsten mineralization. On the SE side of the mine, a quartz vein andskarn zone were sampled (sample 2893) from a dump and adit. This site was identified As being part of the digger claims staked in 1984 by barium inc, of reno, nv. Mineralization associated with this site includes molybdenite, pyrite, chalcopyrite, and possibly argentiferous cosalite, a lead-bismuth sulfosalt. About a half mile ese of main workings was a caved adit along the E- W drainage which cut a n-trending shearzone. The shear was in pyritized sediments reported to have carried Au-ag mineralization. Sample 2892 was taken from both the dumps and the pyritized shearzone. Sample 2888 was taken selectively from the big ore bin on the lower west side of the main workings and should be considered a composite of the main mine workings. The SE tactite body is 400 ft long, u-shaped with the 2 arms of the u about 50 ft thick, grading into calc-silicate hornfels on the west, faulted along the east margin. Some scheelite occurs in altered quartz monzonite adjacent to the main tactite body. This record has been merged with m231150, which has been deleted.

Deposit type: W skarn

Development: Ne W staking on SE side of main hill (1985). Digger claims staked in nov 1984 by barium inc. Of reno, nv. Mine is on patented land purchased from southern pacific by stoddard, turner and crosby in 1943

Geology: Abundant pyrite, largely oxidized, occurs in the hornfels between the two tactite bodies the large, irregularly-shaped felsite dike bordering crosby mine on east has disseminated pyrite and has been prospected in a minor way for gold and silver. Tactite body is cut off to the N and E by quartz monzonite, and on the SE by a large nearly circular barren white quartz plug with a diameter of about 750 ft. Cosalite occurs in late-stage quartz veins which cut tactite, scheelite is present in pegmatite and altered quartz monzonite next to tactite.

Rock formation(s): Auld Lang Syne Group;Nightingale Batholith


Ore(s): Tactite Zone Formed At Contact Of Igneous And Sedimentary Rocks.

Other Databases

Link to USGS MRDS:	10111468

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References