|Quadrangle map, 1:250,000-scale||JU|
|Quadrangle map, 1:63,360-scale||C-6|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is at an elevation of approximately 115 feet, above the northeast shore of Sandy Cove in Glacier Bay. It is in the NW1/4 section 30, T. 36 S., R. 57 E. of the Copper River Meridian. The location is accurate.|
The Sandy Cove prospect was staked in 1933 and an 11-foot adit was completed by 1937 (Brew and others, 1978). The only recorded production was a 4-ton smelter test shipment made prior to 1938. In 1966 the U.S. Geological Survey sampled and mapped the adit and surrounding areas (MacKevett and others, 1971). The deposit consists of discontinuous, gold-, copper-, and silver-bearing quartz veins and adjacent altered zones, mainly in quartz monzonite and monzonite that forms small intrusions in the predominant limestone terrain. The adit is driven on a discontinuous altered zone that strikes northeast and dips steeply east. The altered zone ranges from 0.2 feet to 4.5 feet thick and contains quartz stringers and veins up to 2 feet thick. Chalcopyrite and pyrite form disseminations in the quartz veins and the wallrock, and the sulfides also occur discontinuous, massive bands up to 0.6 foot thick in the veins. Minor scheelite is also present. Alteration products are chlorite, epidote, sericite and hydromuscovite. The quartz monzonite and monzonite are silicified near the veins. Vein samples from the adit assayed up to 0.333 ounce of gold per ton, 3.0 percent copper, and 1.75 ounces of silver per ton. Samples of a vein 100 feet from the adit contained 0.588 ounces of gold per ton, 0.583 ounce of silver per ton, and more than 10 percent copper (Brew and others, 1978).The general area is underlain by deformed and metamorphosed Silurian or Devonian carbonate, clastic and volcanic clastic rocks that have been intruded by Upper Jurassic and Lower Cretaceous granitic and dioritic rocks (Brew and others, 1992).
|Geologic map unit||(-135.973367524055, 58.7209297294689)|
|Alteration of deposit||Silicification and chlorite-epidote-sericite-hydromuscovite alteration.|
|Workings or exploration||The Sandy Cove prospect was staked in 1933 and an 11-foot adit was completed by 1937. The only recorded production was a 4-ton smelter test shipment made prior to 1938. Only surface sampling since the 1930s.|
|Indication of production||None|
|Production notes||The only recorded production was a 4-ton smelter test shipment made prior to 1938.|
Additional commentsThis prospect is in the Glacier Bay National Park and Reserve.
Brew, D.A., Himmelberg, G.R., Loney, R.A., and Ford, A.B., 1992, Distribution and characteristics of metamorphic belts in the southeastern Alaska part of the North American Cordillera--Metamorphic styles in young and ancient orogenic belts: Journal of Metamorphic Geology, v. 10, no. 3, p. 465-482.
Brew, D.A., Johnson, B.R., Grybeck, D., Griscom, A., Barnes, D.F., Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources of the Glacier Bay National Monument Wilderness Study Area, Alaska: U.S. Geological Survey Open-File Report 78-494, 670 p., 7 sheets.
|Reporters||J.C. Barnett and L.D. Miller (Juneau, Alaska )|
|Last report date||12/15/2001|