COMPARISON OF THE MAGNETIC-PROPERTIES AND MOSSBAUER ANALYSIS OF GLASSFROM THE CRETACEOUS-TERTIARY BOUNDARY, BELOC, HAITI, WITH TEKTITES

The magnetic properties of black Beloc glass have been measured. The C urie constant, the magnetization, and the magnetic susceptibility of t he Beloc glass fall within the known ranges observed for tektites. How ever, the temperature-independent component of the magnetic susceptibi lity is slightly higher than that found for tektites. Moreover, it is not possible to match the experimental magnetic data for the Beloc gla ss with the calculated values using the previously reported Fe3+/Fe2ratio of 0.7. The oxidation state of Fe was therefore redetermined by Mossbauer measurements, and the Fe3+/Fe2+ ratio was found to be 0.024 +/- 0.015. Using the redetermined value of the ratio, the magnetic par ameters were again calculated using formulas that are applicable to te ktites, and good agreement was found between the calculated and experi mental values. The experimental magnetic measurements and the redeterm ined Fe3+/Fe2+ ratio of the Beloc glass specimens are essentially the same as those found for tektite glass.