Beryllium-10 in Australasian Tektites: Evidence for a Sedimentary Precursor

See allHide authors and affiliations

Science  19 Nov 1982:
Vol. 218, Issue 4574, pp. 787-789
DOI: 10.1126/science.218.4574.787


Each of seven Australasian tektites contains about 1 x l08 atoms of beryllium-10 (half-life, 1.53 x 106 years) per gram. Cosmic-ray bombardment of the australites cannot have produced the measured amounts of beryllium-10 either at the earth's surface or in space. The beryllium-10 contents of these australites are consistent with a sedimentary precursor that adsorbed from precipitation beryllium-10 produced in the atmosphere. The sediments must have spent several thousand years at the earth's surface within a few million years of the tektite-producing event.