Tuthill Peak Prospect, Haines, Alaska, USAi

Regional Level Types
Tuthill Peak Prospect	Prospect
Haines	City Borough
Alaska	State
USA	Country

Location: This prospect is approximately 2 miles west of Lynn Canal and 4 miles west of Sullivan Island. It is at an elevation of about 4,000 feet, 1/2 mile west of peak 4260 and 2 miles north of the Sullivan River, in the NE1/4 section 8, T. 34 S., R. 60 E. of the Copper River Meridian. The Sullivan River is not named on the current (1996) edition of the D-5 topographic map. The location is accurate.
Geology: In 1989, Placer Dome U.S. discovered a 30-foot by 50-foot area of arsenopyrite-bearing trachyte breccia at this site. The area is bounded by high-angle, northwest-trending faults. Samples contained up to 0.4 ounce of gold per ton. The deposit is interpreted to be the result of remobilization of a deep massive-sulfide deposit along a high angle fault (Bull, 1991). This deposit is one of many in the Dream prospect area that includes numerous veins, stockworks, stratabound and stratiform sulfide deposits (also see JU002, JU006, JU009, JU011, JU013, JU014, JU016, JU019), most of which occur near a volcaniclastic-marble contact. The U.S. Bureau of Mines (Clough and Redman, 1989), International Curator Resources, Ltd. (Huber and Barnett, 1988), and Placer Dome U.S. (Bull and others, 1989) explored the area in the late 1980's and developed a general lithology of the area. They divide the rocks into four major rock units. From the base up, they are: 1) a volcaniclastic unit approximately 2000 feet thick that consists of albite-chlorite schist, chlorite schist, and chlorite-quartz-sericite schist that may in part be metaplutonic as well as metavolcanic; 2) a unit 800 feet thick of micaceous marble, pelitic schist, graphite schist, gray to white, cliff-forming marble, chlorite-amphibole schist, greenstone, and phyllitic graphite schist; and 3) a unit of very fine-grained chlorite-sericite-biotite schist over 1000 feet thick that includes metatuff and pelitic, mafic and graphitic schist. The upper contact of this unit is a thrust fault that trends N-S for several miles; quartz veining is common along the thrust contact. The rocks overlying the thrust are middle- to upper-greenschist-facies graphitic schist, argillite, phyllite, and marble. The metamorphic grade of the rocks varies from mid- to upper-greenschist facies in the south, to amphibolite facies in the north. There have been at least two stages of folding. The Dream prospect area was the site of extensive exploration and mapping from 1987 through 1990 by International Curator Resources Ltd. and Placer Dome U.S. The area was covered by 600 federal mining claims in 1989 and more than 5000 feet of drilling was completed by the end of 1990 (Swainbank and others, 1991). The general area consists predominantly of metamorphosed Silurian and Devonian clastic rocks, limestone, and volcanic units; Permian limestone and siltstone; and small plutons of Tertiary and Cretaceous granodiorite (Brew and Ford, 1985).
Workings: The Dream prospect area was the site of extensive exploration and mapping from 1987 through 1990 by International Curator Resources Ltd. and Placer Dome U.S. The area was covered by 600 federal mining claims in 1989 and more than 5000 feet of drilling was completed by the end of 1990 (Swainbank and others, 1991). Claims are still active on this prospect (Roger Eichman, oral communication 2001).

Commodities (Major) - Au; (Minor) - As
Development Status: None

Other Databases

Link to USGS - Alaska:	JU011

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References