Attempt to Date Early South African Hominids by Using Fission Tracks in Calcite

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Science  13 Sep 1974:
Vol. 185, Issue 4155, pp. 943-944
DOI: 10.1126/science.185.4155.943


Calcite crystals extracted from marrow cavities of bones found in hominid-bearing breccias from Makapansgat and Swartkrans were studied for fossil tracks. The absence of the expected numbers of tracks in these and in calcites from Beds I and II, Olduvai Gorge, combined with the results of laboratory heating experiments, indicates that track annealing has occurred at ambient temperatures and precludes the widespread use of calcite for fission track dating.