URANIUM ESTIMATION AND ISOTOPIC DISEQUILIBRIUM STUDY OF SIWALIK FOSSIL BONES

Solid-state nuclear track detectors have been used for measuring urani um and thorium concentrations in fossil bone samples collected from th e Siwalik Himalayas of India. The fission track measurement yields ura nium concentration alone, while alpha-autoradiography of samples under secular equilibrium yields the total uranium and thorium concentratio ns. Thus, by combining the results of both measurements, uranium and t horium concentrations are determined. The results of uranium content, as determined by fission track analysis, are distinctly different from those of alpha-autoradiography, indicating the existence of radioacti ve disequilibrium in Siwalik fossil bones.