The study of age relations among the Australian tektites (australites) has led to a paradox. On the one hand, K-Ar and fission-track studies give an age of 700,000 yr. On the other hand, stratigraphic studies in Australia indicate that the australites fell between 7,000 and 20,000 yr ago. Age, chemical, petrographic, morphological, and geographical studies link the australites to tektites found in Indonesia, Southeast Asia, and the Philippines. These tektites have stratigraphic ages consistent with their K-Ar and fission-track ages of 700,000 yr. The discovery of microtektites in deep-sea sediments adjacent to Australia that have a stratigraphic age of 700,000 (based on their association with the Brunhes-Matuyama reversal boundary) indicates that the australites also fell 700,000 yr ago. However, Chalmers and others (1976) have recently questioned the relationship between the microtektites and australites and have reaffirmed the low stratigraphic age of the australites. This paper reviews the evidence and concludes that the microtektites are indeed part of the Australasian strewn field and that the occurrence of australites in what are apparently late Pleistocene to post-Pleistocene deposits indicates that they were probably eroded and redeposited at this time.

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First page of Australasian microtektites and the stratigraphic age of the australites
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