Unnamed Occurrence (ARDF - ID123; northwest of upper Otter Creek), Iditarod Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrence (ARDF - ID123; northwest of upper Otter Creek)	- not defined -
Iditarod Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: This occurrence is in a saddle of a northeast-trending ridge about 4 miles northeast of Discovery camp on Otter Creek and 0.2 mile northeast of hill 1807. The occurrence is at an elevation of about 1,700 feet near the southwest corner of section 20, T. 28 N., R. 46 W., of the Seward Meridian. The location is accurate.
Geology: This occurrence is a zone of quartz stringers in heavily iron-oxide-stained sandstone of the Upper Cretaceous, Kuskokwim Group. The quartz stringers are next to a quartz-feldspar porphyry dike (Bundtzen and others, 1992). The dike trends northeast along the ridge. Grab samples contained up to 200 parts per million (ppm) silver, 2.00 percent lead, more than 2,000 ppm antimony, 2,000 ppm zinc, 200 ppm copper, 50 ppm tin, 1,600 ppm arsenic, 100 ppm cadmium, and 18 ppm bismuth (McGimsey and others, 1988; Bundtzen and others, 1992). The primary sulfides are entirely oxidized, but the original primary minerals probably included galena or a lead sulfosalt and sphalerite.
Workings: Surface samples were collected by the U.S. Geological Survey and Alaska Division of Geological and Geophysical Surveys in 1986 (McGimsey and others, 1988; Bundtzen and others, 1992).
Age: Undated; a nearby intrusion is 70.5 Ma (Bundtzen and others, 1992).
Alteration: Intense iron-oxide staining.

Commodities (Major) - Ag, Pb; (Minor) - As, Bi, Cd, Cu, Sb, Sn, Zn
Development Status: None
Deposit Model: Sn-polymetallic deposit or Polymetallic vein (Cox and Singer, 1986; model 20b o

Other Databases

Link to USGS - Alaska:	ID123

Other Regions, Features and Areas containing this locality

References