Geologic setting and mineralization of the Kougarok Sn(Ta-Nb) deposit, seaward peninsula, Alaska

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6460767

Puchner, C C

The Kougarok tin (tantalum-niobium) deposit is located in the north-central Seward Peninsula, roughly 130 kilometers north of Nome, Alaska. Tin and tantalum-niobium mineralization occur within granitic dikes, subhorizontal sheets, plugs, and in schists adjacent to the granite bodies. Rb/Sr and K/Ar age determinations indicate the granites at Kougarok are late Cretaceous in age and coeval with other tin granites of the Seward Peninsula. The host rock to the granites at Kougarok is polydeformed pelitic schists of possible Precambrian age. Known mineralization occurs in four geologic settings: 1) within steep cylindrical pipes of greisenized granite; 2) in greisenized dikes; 3) in greisen along the roof zone of a subhorizontal granite sheet; and 4) as stringer zones in schists. Tin mineralization is known in all the above geologic environments and occurs dominantly as disseminated cassiterite in quartz+/-tourmaline+/-topaz greisen. Grades of significant tin mineralization range from 0.1 to 15 percent tin and average approximately 0.5 percent tin. Tantalum-niobium mineralization is confined to the roof greisen environment. Tantalite-columbite occurs as disseminated grains in white mica altered granite lateral to tin-bearing quartz-tourmaline greisen. Grades for both tantalum and niobium range from 0.02 to 0.05 percent.

• Research Organization: Anaconda Minerals Company, AK (USA)
• OSTI ID: 6460767
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
AGE ESTIMATION
ALASKA
CHALCOGENIDES
FEDERAL REGION X
GEOLOGIC HISTORY
GRANITES
IGNEOUS ROCKS
ISOTOPE DATING
METAMORPHIC ROCKS
MINERALIZATION
MINERALOGY
MINERALS
NORTH AMERICA
ORES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PETROGENESIS
PLUTONIC ROCKS
QUARTZ
ROCKS
SCHISTS
SILICON COMPOUNDS
SILICON OXIDES
TIN ORES
USA