ISOTOPIC EVIDENCE ON THE ORIGIN AND AGE OF THE BLIND RIVER URANIUM DEPOSITS

Journal Article · Fri Jan 01 00:00:00 EST 1960 · J. Geophys. Research

DOI:https://doi.org/10.1029/JZ065i001p00341· OSTI ID:4186431

Mair, J A; Maynes, A D; Patchett, J E; Russell, R D

Isotopic analyses of lead extracted from a variety of minerals from Blind River. Ontario, are repeated. The detrital minerals monazite and zircon both give leadratio ages of 2500 million years. The uraainite ore gives a lead- ratio age of 1700 m a. Other isotopic evidence is quoted to suggest that the age of the sediment in which the uranium is found may also be approximately 1700 m y, or older. The lead found in pyrite, pyrrhotite, sericite, and feldspar has anomalous isotopic ratios which can be explained by the hypothesis that they received additions of radiogenic lead from the uraninites (presumed to be 1700 m y old) 1200 to 1300 m y ago. In any case the age of these minerals, in the sense of time of last chemical alteration, is not greater than 1450 plus or minus 150 m y. All our measurements can be interpreted without asauming a major period of mineralization more recent than 1000 m y ago, although we are unable to rule out such a possibility from our evidence. (auth)

• Research Organization: Univ. of Toronto
• Sponsoring Organization: USDOE
• NSA Number: NSA-14-007628
• OSTI ID: 4186431
• Journal Information: J. Geophys. Research, Vol. Vol: 65; Other Information: Orig. Receipt Date: 31-DEC-60
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

GEOLOGY, MINERALOGY, AND METEOROLOGY
AGE ESTIMATION
ALUMINUM SILICATES
CANADA
CHEMICAL REACTIONS
DECAY
DECOMPOSITION
DEPOSITS
DISTRIBUTION
FELDSPARS
IRON SULFIDES
ISOTOPES
LEAD ISOTOPES
MICA
MINERALIZATION
MINERALS
MONAZITES
PYRITE
PYRRHOTITE
QUALITATIVE ANALYSIS
SILICATES
URANINITES
URANIUM MINERALS
URANIUM ORES
ZIRCONIUM OXIDES