231Pa 235U and 230Th 234U ages were determined for 17 carnotites from two areas in Israel. For this purpose, a simplified one-step method was used to purify the protactinium, the extraction into TTA (thenoyl-trifluoro-acetone) at high acidity. Using the test of concordance between the two dating methods, 12 of the 17 carnotites were found to have acted as closed chemical systems whereas 4 seem to have gained uranium. The details of the relationships between the 231Pa 235U and the 230Th 234U ages suggest that the uranium gain which took place in the latter 4 cases, occurred in a manner which was approximately continuous and linear.
All Science Journal Classification (ASJC) codes
- Geochemistry and Petrology