THE DISTRIBUTION OF THORIUM AND URANIUM IN A PENNSYLVANIAN WEATHERING PROFILE

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

DOI:https://doi.org/10.1016/0016-7037(62)90049-2· OSTI ID:4740992

Pliler, R; Adams, J A.S.

Eleven samples representing a pre-Pennsylvanian weathering profile on the Boulder Creek granodiorite near Boulder, Colorado, were analyzed for thorium and uranium by gamma -ray spectrometric and chemical methods. In an effort to determine the possible sites of thorium and uranium in the samples, a study of their leachability in hot 2 N hydrochloric acid was undertaken. Fresh granodiorite was found to contain 9.3 ppm thorium and 2.5 ppm uranium. The first stages of weathering resulted in an apparent removal of 25% of the thorium and 60% of the uranium present in the original granodiorite. The leaching study of the fresh granodiorite demonstrated that as much as 90% of the thorium and 60% of the uranium could be removed by an acid leach solution, This seems to indicate that most of the thorium and uranium in the fresh rock is situated in acid soluble minerals or in interstitial materials. After the initial drop of the concentration in the lowest part of the weathered mantle, the total uranium and thorium content of the weathered rock increased by a factor of at least 4 in the uppermost, most-weathered rock material. Leaching studies of the weathered rock indicated that uranium is present largely in the primary resistates, such as zircon, xenotime, and apatite, and thorium occurs mainly in or on clays or in the secondary resistates --- minerals formed during weathering. (auth)

• Research Organization: Rice Univ., Houston, Tex.
• NSA Number: NSA-17-004697
• OSTI ID: 4740992
• 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

ACIDITY
APATITES
CALCIUM PHOSPHATES
CLAYS
DISTRIBUTION
GAMMA SPECTROMETERS
GEOLOGY, MINERALOGY, AND METEOROLOGY
GRANITES
GRANODIORITES
HYDROCHLORIC ACID
IGNEOUS ROCKS
LEACHING
MINERALS
PENNSYLVANIA
QUALITATIVE ANALYSIS
ROCKS
SOLUTIONS
THORIUM
URANIUM
USA
XENOTIME
YTTRIUM PHOSPHATES
ZIRCON
ZIRCONIUM SILICATES