Archean Rocks in Antarctica: 2.5-Billion-Year Uranium-Lead Ages of Pegmatites in Enderby Land

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Science  26 Oct 1979:
Vol. 206, Issue 4417, pp. 443-445
DOI: 10.1126/science.206.4417.443


Uranium-lead isotopic data indicate that the granulite-facies Napier complex of Enderby Land, Antarctica, was cut by charnockitic pegmatites 2.5 billion years ago and by pegmatites lacking hypersthene 0.52 billion years ago. The 4-bil-lion-years lead-lead ages (whole rock) reported for the Napier complex are rejected since these leads developed in three stages. Reconstructions of Gondwanaland suggest that the Napier complex may be a continuation of the Archean granulitic terrain of southern India.