Worcester

Prospect, Inactive

Commodities and mineralogy

Geographic location

Quadrangle map, 1:250,000-scale TE
Quadrangle map, 1:63,360-scale C-1
Latitude 65.615
Longitude -165.132
Nearby scientific data Find additional scientific data near this location
Location and accuracy This locality is at 2,500 to 2,600 feet on a ridgecrest between headwater tributaries of Henry Creek, a west tributary to the Kougarok River. It is in the east-central Teller C-1 quadrangle, 1 mile south of the Henry Creek occurrence (TE074) and 5.4 miles southeast of the summit of Kougarok Mountain. This is locality 18 of Cobb and Sainsbury (1972) although they referred to it as an unnamed occurrence and called their locality 17 the Worcester prospect. The description by Sainsbury and others (1969, p. 22) suggests that this locality is actually the Worcester prospect. Cobb (1975) summarized references to this prospect under the name 'Worcester'.

Geologic setting

Geologic description

Silica-rich rocks are present at the base of a marble assemblage overlying schist. Small amounts of copper-bearing sulfide minerals are present in vertical joints and secondary copper staining is present. The occurrence has been explored by two short adits. Because of the presence of observed mineralization and early exploration workings here, this location rather than the locality 1 mile to the north (Cobb and Sainsbury, 1972) is considered the Worcester prospect of Mertie (1918).
Sainsbury and others (1969, p. 37) report spectrographic analyses for four samples from this locality. A selected high-grade sample contained 7.1% copper and 7,000 ppm zinc. Traces of gold and mercury were also reported in these analyses.
This occurrence is similar in setting and character to the Ward mine (TE071) north of Kougarok Mountain. The summary characterization of this type of Seward Peninsula mineral deposit by Sainsbury (1975, p. 90-94) contains inconsistencies with some descriptions of these deposits. Their origin is uncertain and other possibilities should be considered. One possiblity is that the silica-rich rocks are quartzites and that there is a stratigraphic control to the Ward deposit and similar occurrences elsewhere on Seward Peininsula. Quartzite at the base of the regional carbonate assemblage is recognized elsewhere in the Kougarok Mountain area (Puchner, 1986, p. 1777).
Geologic map unit (-165.134689481729, 65.6142691034452)
Mineral deposit model Silica-rich rock with minor copper-bearing mineralization at the base of a marble assemblage overlying schist
Age of mineralization Paleozoic (?); the silica-rich rocks are apparently metamorphosed and would therefore predate mid-Mesozoic deformation and metamorphism in the region. The associated marbles are probably Paleozoic in age. However, the relation of copper metallization to the genesis of the silica-rich rocks is not clear.
Alteration of deposit The development of silica-rich rocks at the base of marble overlying metapelitic rocks, by whatever process, characterizes the deposit.

Production and reserves

Workings or exploration Two short adits and surface pits are present.
Indication of production None
Reserve estimates Not defined

References