Lyengholm, Hargood and Larson

Occurrence, Inactive

Alternative names

Black Devil

Commodities and mineralogy

Main commodities Sb
Ore minerals stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale B-8
Latitude 60.4802
Longitude -149.6941
Nearby scientific data Find additional scientific data near this location
Location and accuracy The occurrence is located in the SE1/4 section 31, T. 5 N., R. 2 W. of the Seward Meridian. It is situated at an approximate elevation of 800 feet on the divide between Dry Creek and Kenai Lake. This is location 32 of Cobb and Richter (1972), location 42 of MacKevett and Holloway (1977), location 63 of Cobb and Tysdal (1980), and location S-238 of Jansons and others (1984). This location is accurate to within a quarter of a mile.

Geologic setting

Geologic description

The occurrence consists of a highly fractured and altered dike, 6 to 8 feet wide, that cuts slate county rock (Grant and Higgins, 1909). Slate in this area is mapped as Valdez Group of Late Cretaceous age (Tysdal, 1978 [MF-880-A]). The dike is a fine-grained, sheared, gray, acidic rock. Fractures in the dike have been healed by quartz that contains stringers and disseminated acicular crystals of stibnite. The age of the dike is unknown. Tysdal (1978 [MF-880-A]) reported that local quartz veins contain stibnite, but he provided no assay results.
Geologic map unit (-149.696241094675, 60.479616960989)
Mineral deposit model Polymetallic veins (Cox and Singer, 1986; model 22c)
Mineral deposit model number 22c
Age of mineralization Cretaceous or younger; the veins cut rocks of the Valdez Group of Late Cretaceous age.
Alteration of deposit Although the dike is reported to be altered, no information regarding the type of alteration is available in the literature.

Production and reserves

Workings or exploration No workings or improvements are reported. Assays of the antimony ore are reported to show neither gold nor silver (Grant and Higgins, 1909). No assay information is available regarding the antimony content of the ore.
Indication of production None

Additional comments

The U.S. Bureau of Mines indicated that the dike is probably a continuation of the mineralized dike at the K and T prospect (SR181) (Jansons and others, 1984).



Hoekzema, R.P., and Sherman, G.E., 1983, Mineral investigations in the Chugach National Forest, Alaska (Peninsula study area): U.S. Bureau of Mines in-house report; held at U.S. Bureau of Land Management Alaska State Office, Anchorage, 524 p.
Reporters Jeff A. Huber and Carol S. Huber (Anchorage)
Last report date 3/5/2000