THE DISTRIBUTION OF THORIUM, URANIUM, AND POTASSIUM IN THE MANCOS SHALE

Journal Article · Thu Nov 01 04:00:00 EST 1962 · Geochimica et Cosmochimica Acta (England)

DOI:https://doi.org/10.1016/0016-7037(62)90048-0· OSTI ID:4756972

Pliler, R; Adams, J A.S.

Over 135 samples of upper Cretaceous Mancos shale were analyzed for uranium, thorium, and potassium by chemical and radiometric means. The samples were collected from 16 localities in Colorado, Utah, Arizona, and New Mexico. The average concentrations found in the Mancos shale samples were 10.2 ppm thorium, 3.7 ppm uranium, and 1.9% potassium as metal. The average Th/U ratio was 3 : 1. For the most part, variations in the thorium, uranium, and potassium concentrations were gradual and took place over large distances. Thorium, Th/U ratio, and potassium tended to decrease and uranium tended to increase with distance from the upper Cretaceous shoreline. The K/Th ratio in the shale, including sandy intertongues, showed remarkedly little variation on a regional basis. Laboratory studies indicated that the uranium in the Mancos shale was present largely in the fine-grained primary resistate minerals, and the thorium occurred in the fine-grained secondary resistates or fixed in or on clays. (auth)

• Research Organization: Rice Univ., Houston, Tex.
• NSA Number: NSA-17-004696
• OSTI ID: 4756972
• Journal Information: Geochimica et Cosmochimica Acta (England), Journal Name: Geochimica et Cosmochimica Acta (England) Vol. Vol: 26; ISSN GCACA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ARIZONA
CLAYS
COLORADO
DETECTION
DISTRIBUTION
GEOLOGY, MINERALOGY, AND METEOROLOGY
GRAIN SIZE
MINERALS
NEW MEXICO
POTASSIUM
QUALITATIVE ANALYSIS
QUANTITY RATIO
RADIOACTIVITY
ROCKS
SHALES
THORIUM
URANIUM
USA
UTAH