Tektites are the product of melting and quenching of terrestrial rocks during hypervelocity impacts on the Earth. The advent of the highly-sensitive negative thermal ionization technique (NTIMS) for Re-Os isotopic analysis makes this system ideally suited to the problem of understanding the often elevated siderophile element content of tektites. The P.I.s propose to carry out Re-Os isotopic studies by NTIMS on tektites from the Australasian and Ivory Coast Strewn fields and on the Auoelloul glasses. With the Re-Os isotopic system there is the unique opportunity to determine if the Os found in tektites is really extraterrestrial, crustal or a mixture of both. This is necessary for showing whether the siderophile element signatures in tektites are a result of meteorite contamination or in-situ reduction of the target rocks.
