Neirod - East Prospect, Innoko Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Neirod - East Prospect	Prospect
Innoko Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

See Montana Saddle prospect (MD018).
Location: The Neirod-East prospect lies along a steep westerly slope of the Cripple Creek Mountains at an elevation of 2,350 feet (716 m) in Section 33, T. 22 S., R. 16 E., of the Kateel River Meridian. The reporter investigated the site in 1996.
Geology: An extensive altered zone in border phase plutonic rocks and hornfels extends in a north-south direction for a distance of about 1,968 feet (600 m). The mineralization consists of : (1) ferricrete breccia in the border phase of the Cripple Creek Mountains pluton; (2) stockwork veins in hornfels; and (3) quartz stockwork in fine grained monzonite. The Neirod-East prospect falls within a north 40 degrees east alignment of several metallic lodes--including the Moose Jaw (MD019), Montana Saddle (MD018), and Wyoming Lode (MD016) prospects. Age of mineralization is inferred to be Late Cretaceous based on 71.0 Ma age of adjacent pluton (Bundtzen and others, 1997). Microprobe analyses of mineralization from the Neirod-East prospect indicates the presence of boulangerite, jamesonite, and zinkenite in addition to the megascopic arsenopyrite observed in hand specimens. Gold is intimately intergrown with jamesonite - an uncommon association (Bart Cannon, written communication, 1998). Five chip channel samples collected along about 1,640 feet (500 m) strike of the zone contained up to 760 ppb gold, 1.00 percent arsenic, 5,360 ppb mercury, and 178 ppm copper (Bundtzen and others, 1997).
Workings: Five chip channel samples collected along about 1,640 feet (500 m) strike of the zone contained up to 760 ppb gold, 1.00 percent arsenic, 5,360 ppb mercury, and 178 ppm copper (Bundtzen and others, 1997).
Age: Late Cretaceous (inferred) based on 71.0 Ma age of adjacent pluton (Bundtzen and others, 1997).
Alteration: Extensive sericitization of plutonic rocks; late tourmaline metasomatism.
Reserves: None.

Commodities (Major) - Au; (Minor) - As, Cu, Hg, Pb, Sb, Zn
Development Status: No
Deposit Model: Porphyry Cu-Au (Cox and Singer, 1986; model no. 20c)

Other Databases

Link to USGS - Alaska:	MD020

Other Regions, Features and Areas containing this locality

References