SOME THORIUM DEPOSITS IN WESTERN MONTANA AND EAST-CENTRAL IDAHO

Technical Report · Fri Mar 01 04:00:00 EST 1957

OSTI ID:4254083

Moen, W S

Significant deposits of thorium occur throughout an area 7 miles long and 4 miles wide in the Lemhi Pass area of south-western Montana and east-central Idaho. A small deposit of thorium has also been recently exposed in the Duck Creek area of Broadwater County, Montana. In the Lemhi Pass area, the thorium mineral, thorite, is found in quantz-hematite veins that cut quantzites of the Belt series of Precambrian age. The thorite is fine grained and admixed with iron oxides; it is accompanied by minor amounts of uranium and rare earths. The Little Brown Egg thorium deposit in the Duck Creek area consists of pods and pockets of massive thorite occurring in aplite dikes which cut limestones of the Belt series. The average grade of 7 thorium deposits in the Lemhi Pass area and 1 deposit in the Duck Creek area is 0.72% thorium oxide. Most deposits are the narrow vein type. One deposit in the Lemhi Pass area contains a significant amount of ore with an average grade of about 1% thorium oxide. (auth)

• Research Organization: Grand Junction Operations Office. Salt Lake Branch Office, AEC
• NSA Number: NSA-13-019053
• OSTI ID: 4254083
• Report Number(s): RME-2061(Pt.I)
• Country of Publication: United States
• Language: English

Related Subjects

APLITES
CALCIUM CARBONATES
DEPOSITS
GEOLOGY AND MINERALOGY
HEMATIN
IRON OXIDES
LIMESTONE
MONTANA
QUARTZ
RARE EARTHS
ROCKS
THORITE
THORIUM ORES
THORIUM SILICATES
URANIUM