The occurrence and properties of metatyuyamunite Ca(UO2)2(VO4)2.3-5 H2O
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Trace Elements Investigations↗
Geology topics
M.N. Girhard
Publications and source records attributed to M.N. Girhard.
A preliminary report on methods of determining the age of Colorado plateau carnotite
Four methods of dating Colorado Plateau carnotite have been examined and evaluated: mineralogic methods, radioactive-equilibrium methods, lead-uranium-ratio methods, and lead-isotope methods. The data on 12 high-grade samples, from a suite of 50 representative carnotite ores, are presented.
Colorado↗
Study of radioactive equilibrium in Carnotite ores of the Colorado Plateau
The purpose of this study was to determine the age of Colorado Plateau carnotite. In addition to quantitative analyses of uranium and lead, the radium-uranium equilibrium of each sample was studied. Of the 12 samples studied, 10 are deficient in radium. If a minimum age of 130 million years is chosen for the enclosing sediments, 11 samples are deficient in lead. This deficiency may be explained by (1) leaching of lead or (2) assuming too great an age. Three samples, chosen for lead-isotope analysis, have Pb 207 /Pb 206
Colorado↗