Unnamed Prospects (ARDF - CA016; at head of Quartz Creek); Saddle, Fairhaven Mining District, Northwest Arctic Borough, Alaska, USAi

Regional Level Types
Unnamed Prospects (ARDF - CA016; at head of Quartz Creek); Saddle	- not defined -
Fairhaven Mining District	Mining District
Northwest Arctic Borough	Borough
Alaska	State
USA	Country

Location: These prospects are at an elevation of about 1,250 feet on a ridge between the headwaters of Kiwalik River and Quartz Creek. The site is in section 22, T. 1 N., R. 13 W., of the Kateel River Meridian. It is location 32, figure 2 of Miller and Elliot (1969).
Geology: This area is on the eastern Seward Peninsula where base metal, silver, and some gold-bearing mineralization occurs in a 4 x 16 kilometer belt of hydrothermally altered, hornfelsed andesite and intrusive rocks. The Cretaceous andesitic volcanic rocks are locally intruded by andesitic dikes and elongate stocks of monzonite, syenite, and quartz monzonite. A swarm of subparallel aplite and monzonite dikes and a small rhyolite stock locally intrude the mineralized belt. Mineralization and alteration are localized in structurally down-dropped blocks adjacent to coarse-grained intrusions that include the large, composite Granite Mountain pluton about 3 kilometers to the southeast. The mineralization was originally discovered by the U.S. Geological Survey in the 1960s (Miller and Elliott, 1969). Greatland Exploration Ltd. explored this prospect in the 1970s and still holds mining claims in the area (Ron Sheardown, oral communication, 2005). This exploration included geologic mapping, stream-sediment surveys, grab sampling of rocks and soils, two local soil geochemical surveys, and four short diamond drill holes. The four drill holes are in one area, total 449 meters in length, and reached vertical depths of 50 to 126 meters. Attempts to obtain geophysical data were inconclusive. Argentiferous galena, sphalerite, pyrite, arsenopyrite, and minor chalcopyrite occur in veins and disseminations both in volcanic hornfels and intrusive rocks (Miller and Elliott, 1969). The sulfide minerals commonly are in quartz-tourmaline veins and replacements. Massive pyrrhotite with some chalcopyrite locally replaces volcanic hornfels. Sphalerite-, galena-, and chalcopyrite-bearing calcite veins are widely scattered through the mineralized belt. Sulfide mineralization commonly is structurally controlled along fractures, faults, and shear zones that cut all bedrock units. Placer gold was recovered from Quartz Creek for many years. Highly anomalous lead, zinc, silver, copper and boron are common in stream sediments of upper Quartz Creek and its tributaries. Rock and soil samples from the area contain up to 300 parts per million (ppm) silver, 1 ppm gold, more than 10,000 ppm arsenic, more that 10,000 ppm boron, more than 500 ppm cadmium, 2,000 ppm cobalt, 2,000 ppm copper, more than 5,000 ppm manganese, more than 19 percent lead, 100 ppm scandium, and more than 5 percent zinc. One sample contained more than 10,000 ppm tungsten. Soil surveys identified several highly anomalous zones including one 1.3 x 1.4 kilometer area, open on one side, where lead values exceed 200 ppm and zinc values exceed 300 ppm; many lead and zinc values exceed 1,000 ppm in this area. Gold was commonly not determined in the early geochemical investigations. In 2005, Linus Gold Corporation (2007, Anomalies) began work in the area by staking about 30 square miles of claims, followed by a geologic reconnaissance, rock sampling and a geochemical soil survey that defined several anomalous areas in base and precious metals. Linus carried out considerable work in the area in the summer of 2006, including 4 diamond drill holes that totaled 2,970 feet. All the drill holes intersected altered, mineralized volcanic rocks that were cut by dikes or sills of syenite and granodiorite that were in turn cut by thin rhyolite to dacite dikes. A new gold prospect in intensely altered plutonic rocks was found at the surface near Quartz Creek; grab samples contained 114 to 325 parts per billion (ppb) gold, 10.6 to 35.4 ppm silver, up to 872 ppm copper, and 2.1 percent combined lead and zinc. Surface samples at the Saddle prospect contained up to 2.58 grams of gold per ton, 250 grams of silver per ton, and 3.0 percent lead and zinc.
Workings: The mineralization was originally discovered by the U.S. Geological Survey in the 1960s. Greatland Exploration Ltd. explored this prospect in the 1970s and still holds mining claims in the area. This exploration included geologic mapping, stream-sediment surveys, grab sampling of rocks and soils, two local soil geochemical surveys, and four short diamond drill holes. The four drill holes are in one area, total 449 meters in length, and reached vertical depths of 50 to 126 meters. Attempts to obtain geophysical data were inconclusive. In 2005, Linus Gold Corporation (2000 began work in the area by staking about 30 square miles of claims, followed by a geologic reconnaissance, rock sampling and a geochemical soil survey that defined several anomalous areas in base and precious metals. Linus carried out considerable work in the area in the summer of 2006, including 4 diamond drill holes that totaled 2,970 feet, and considerable surface work and sampling.
Age: Late Cretaceous.
Alteration: Volcanic hornfels and intrusive rocks are variably altered and are cut by sulfide, calcite, and quartz-tourmaline veins. Volcanic hornfels and intrusive rocks are locally intensely replaced by sericite, pyrite, quartz, and tourmaline. Late carbonate veins and replacements cut intrusive rocks and scapolite is a common alteration mineral in volcanic rocks. Oxidation is extensive and gossan zones characterize the 4 x 16-kilometer mineralized belt.

Commodities (Major) - Ag, Au, Pb, Zn; (Minor) - As, B, Cd, Co, Cu, Mn, W
Development Status: None
Deposit Model: Sulfides with gold values in altered andesite.

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Link to USGS - Alaska:	CA016

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References