580 resultados para URANIUM 234
(Table 4 bis, page 194), Radiochemical data on four successive Mn-rich layers of a West Timor nodule
Resumo:
Massive sulfide samples from the Bent Hill area were analyzed for 230Th/234U and 231Pa/235U disequilibria. Apparent ages calculated from these ratios are between 8.2 and >300 ka. Concordant ages were found for only three samples that originate near the surface from the clastic sulfide zone and suggest "true" ages of between 8.5 and 16.0 ka (mean of 230Th and 231Pa ages). The uranium vs. depth distribution in the Bent Hill Massive Sulfide deposit suggests an open system for uranium for the deeper part of the deposit, which was probably caused by extensive recrystallization processes inhibiting true age determinations.
(Table 3) Details on the U/Th age determinations carried out on two sediment cores from Galway Mound
