A plate tectonic model of the Palaeozoic tectonic history of New South Wales |
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| Authors: | Erwin Scheibner |
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| Institution: | Geological Survey of New South Wales, Department of Mines , A.D.C. Building, 189–193 Kent Street, Sydney, N.S.W., 2000 |
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| Abstract: | A major phase of igneous activity of Late Oligocene to Early Miocene age affects West Kalimantan and Sarawak in northwest Borneo. The suite of igneous rocks, intruded as stocks, sills and dykes, ranges in composition from diorite to granite, the majority being granodiorite, and has geochemical characteristics similar to I‐type granitoids. The locus of magmatic activity was in the thickest part of Late Cretaceous and Early Tertiary sedimentary basins. The age of magmatism, its tectonic position and geochemistry suggest that it is related to deep crustal re‐melting and intrusion in a passive, postsubduction environment. |
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| Keywords: | Borneo dacite geochemistry geochronology Kalimantan postsubduction intrusive rocks |
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