ISOTOPIC GEOCHEMISTRY OF URANIUM AND LEAD. Annual Report for 1959-60

Technical Report · Sun May 01 04:00:00 EDT 1960

OSTI ID:4135911

Kulp, J L; Catanzaro, E J; Miller, D S; Swainbank, I; Wampler, J M

An investigation of the isotopic relations of U, Pb, and S in the minerals of the Colorado Plateau uranium ores was made. The results indicate that the uranium mineralization probably occurred at more than one period of time, depending on the area and the host rock. The geologic occurrence of the Colorado Plateau uranium mineralization is described in general terms along with a short synopsis of proposed origins. The lead loss hypothesis was found to account for the anomalies found in lead isotopic data. From studies on the isotopic geochemistry of the Swedish kolm, it was determined that the uraniurn was concentrated in the formation by direct precipitation from sea water under anaerobic conditions over 500 million years ago. In the Upper Cambrian Swedish kolm, the isotopic age discordance U/sup 238/-Pb/sup 206/ < U/sup 235/--Pb/sup 207/ < Pb/sup 207/--Pb/sup 206/ was found to be present. Preferential removal of Pb/sup 206/ is proposed to be an important cause of the discordance. Both radium and radon were found to be mobile in the kolm under suitable conditions. Techniques were developed for performing uranium and lead isotopic analysis of black shale surrounding the kolm. Studies on the lead isotope relations of the aguilar lead-zinc mine in Argentina suggested deposition in Triassic time from normal magmatic sources. The close association of the mineralization and faulting revealed that the faulting was pre-tertiary. A determination of a low lead content in marine carbonate shells supported the conclusion of Wedepohl that the lead in carbonate rocks is not, on the whole, directly co-precipitated with the carbonate. Age determination studies were performed on zircons from the Little Belt Mountains, Montana, and the Santa Catalina Mountains, Arizona. (C.J.G.)

• Research Organization: Columbia Univ., Palisades, N.Y. Lamont Geological Observatory. Geochemical Lab.
• NSA Number: NSA-14-016887
• OSTI ID: 4135911
• Report Number(s): TID-5966
• Country of Publication: United States
• Language: English

Related Subjects

AGE ESTIMATION
ARIZONA
CARBONATES
COLORADO
DIFFUSION
DISTRIBUTION
GEOCHEMISTRY
GEOLOGY, MINERALOGY, AND METEOROLOGY
LEAD
LEAD ISOTOPES
MINING
MONTANA
PRECIPITATION
QUANTITY RATIO
RADIUM
RADON
ROCKS
SEA
SHALES
SULFUR ISOTOPES
TRANSPORT
URANIUM
URANIUM ISOTOPES
URANIUM MINERALS
URANIUM ORES
USA
ZINC
ZIRCONIUM OXIDES