Cap Prospect, Haines, Alaska, USAi

Regional Level Types
Cap Prospect	Prospect
Haines	City Borough
Alaska	State
USA	Country

Location: This prospect is at the northern edge of Saksaia Glacier at an elevation of about 3,800 feet and approximately 2.1 miles due east of Mt. Henry Clay. It is shown in Figure 7 of Still (1984 [OF 118-84]).
Geology: This prospect consists of barite-rich sulfide lenses up to 8 feet thick in a 50-foot-thick, 220-foot-long, iron-stained zone capped by volcanics that outcrop above the Saksaia glacier. The full extent of the prospect is hidden by glacier and cover. Pyrite, sphalerite, galena and tetrahedrite are found in the barite lenses. Samples contained up to 50% barium, 1.1% zinc, 0.33% lead, 277.7 ppm silver, 1.371 ppm gold, and 100 ppm cobalt. (Still, 1984 [OF 118-84], and Still and others, 1991). The mineralization is near a cupola of Cretaceous quartz diorite. It is mineralogically similar to the other barite-rich deposits lodes in the area such as the Main Zone/Palmer (SK066) and Nunatak (SK058) prospects (MacKevett and others, 1974). Rubicon Minerals (1998) cites the results of work by Newmont Gold Company that includes a 43-foot channel sample that contained 247.6 ppm silver, 0.263 ppm gold, 2,753 ppm zinc, 1,803 ppm lead, and 174 ppm copper as well as a drill hole with a 76.3-foot-thick intercept that averaged 3.7 ounces of silver per ton. This prospect lies along a northwesterly mineral trend that includes the Nunatak (SK058), Cap, and Mt. Henry Clay (SK068) prospects. Rubicon Minerals considers these prospects to all occur at the same mineralized stratigraphic horizon and attributes their distribution to a northwest-trending, shallowly plunging antiform that brings the massive-sulfide horizon close to the surface (Rubicon Minerals, 1998). The Cap prospect and other similar prospects in the Mt. Henry Clay area are probably correlative with the Windy Craggy deposit in Canada and the Greens Creek deposit on Admiralty Island and are therefore Late Triassic (Still, 1984 [OF 118-84]; Newberry and others, 1997).
Age: The Cap prospect and other similar prospects in the Mt. Henry Clay area are probably correlative with the Windy Craggy deposit in Canada and the Greens Creek deposit on Admiralty Island and are therefore Late Triassic (Still, 1984 [OF 118-84]; Newberry and others, 1997).

Commodities (Major) - Ag, Au, Ba, Pb, Zn; (Minor) - Sb
Development Status: None
Deposit Model: Probably a Kuroko- or Besshi-type volcanogenic massive sulfide (Cox and Singer,

Other Databases

Link to USGS - Alaska:	SK060

Other Regions, Features and Areas containing this locality

References