Unnamed (east side of upper Sullivan River)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Au
Other commodities Zn
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale JU
Quadrangle map, 1:63,360-scale D-5
Latitude 58.9441
Longitude -135.4827
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is approximately 3.5 miles west of Lynn Canal and 5 miles west of the Sullivan Island at an elevation of about 800 feet. It is on the east side of upper Sullivan River, which is not named on the current (1996) edition of the D-5 topographic map. The site is in the SW1/4 section 6, T. 34 S., R. 60 E. of the Copper River Meridian. The location is accurate.

Geologic setting

Geologic description

In 1989, Placer Dome U.S. identified several areas of elevated base and precious metals in this area (Bull and others, 1989). The U.S. Bureau of Mines collected a sample of a quartz vein that contained 1.5 ppm gold and 23 ppm silver; a sample of argillite contained 450 ppm zinc (Clough and Redman, 1989).
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 1980s 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).
Geologic map unit (-135.484548262511, 58.9437711341675)

Production and reserves

Workings or exploration 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 had been completed by the end of 1990 (Swainbank and others, 1991).
Indication of production None

References

References

Reporters J.C. Barnett and L.D. Miller (Juneau, Alaska )
Last report date 12/15/2001