Statistical studies of selected trace elements with reference to geology and genesis of the Carlin gold deposit, Nevada

Abstract

Linear regression and discriminant analyses techniques were I applied to gold, mercury, arsenic, antimony, barium, copper, molybdenum, lead, zinc, boron, tellurium, selenium, and tungsten analyses from drill holes into unoxidized gold ore at the Carlin gold mine near Carlin, Nev. The statistical treatments employed were used to judge proposed hypotheses on the origin and geochemical paragenesis of this disseminated gold deposit.

Geology of the Carlin gold deposit, Nevada

“…This value corresponds well to the three median values of 7.5, 8.3, and 8.6 ppm Au re ported by Harris and Radtke (1976) from statistical treat ments of analyses using different numbers of samples. This average value, which is 10 to 15 percent higher than in the other ore bodies, reflects the uncommonly high gold content in the western 75m of the ore zone; along the West ore zone the gold content reaches as high as 150 ppm, owing in part to confinement of the ore solutions against impermeable gouge in the preore north-south-trending normal fault at the west end of the ore body (pl.…”

“…The primary unoxidized ores contain sig nificant amounts of arsenic, antimony, and mercury, but sulfide minerals containing these elements are sparse. Al though the average mercury content (22 ppm) in the West ore zone corresponds closely to that in the Main and East ore zones, the average contents of arsenic (222 ppm) and antimony (52 ppm) are considerably lower than in the Main and East ore zones (Harris and Radtke, 1976).…”

“…(R. L. Akright, written commun. , Hausen and Kerr (1968), Radtke (1973Radtke ( , 1974, Harris and Radtke (1976), Noble and Radtke (1978), Radtke andothers (1979), (1980). Radtke (1974), Noble and others (1977).…”

“…Harris and Radtke (1976) reported average values of 25 ppm Cu, 6 ppm Mo, 26 ppm Pb, 72 ppm Zn, 54 ppm B, 10 ppm W, 1.5 ppm Se, � 41 GENERAL FEATURES OF THE CARLIN DEPOSIT and less than 0.2 ppm Te. In contrast, the average barium content (650 ppm) is higher here than in the other ore zones.…”

Tellurium

“…In part, this may reflect the exceptional fine-grained nature of the ores, so that the telluride minerals are rarely visible. Nevertheless, Harris and Radtke (1976), in one of the first geochemical studies of the Carlin gold deposit itself (which is located in Eureka County, Nev.), indicated a strong gold-tellurium correlation, which would favor the presence of telluride minerals in this deposit type. Emsbo and others (2003) noted minor amounts of telluride minerals and as much as 130 ppm tellurium in ore-related pyrite in the Meikle deposit of Elko County, Nev. Cail and Cline (2001) report values for ores of as much as 180 ppm tellurium in the Getchell trend in Humboldt County, Nev., and Heitt and others (2003) indicate as much as 84 ppm tellurium at the Deep Star deposit in Eureka County, Nev. Ore-stage pyrites in the Carlin ores may contain thousands of parts per million tellurium (Muntean and others, 2011).…”