The Geochemistry of ‘Charnockites’ and Their Constituent Ferromagnesian Minerals from the Precambrian of South-East Sri Lanka (Ceylon)

D. E. De S. Jayawardena1 and D. A. Carswell
Department of Geology, University of Sheffield, Sheffield, SI 3JD
1Present address: Geological Survey Department, 48 Sri Jinaratana Road, Colombo—2, Sri Lanka.

Summary: A chemical and petrographic study of charnockites and pyroxene/hornblende-bearing granulites has been undertaken, and the data used in an interpretation of the petrogenesis of these rocks. Major- and trace-element analyses of fourteen rocks are presented, together with major-element analyses of seven orthopyroxenes, seven clinopyroxenes, two garnets, and three hornblendes. The compositions of the coexisting ferromagnesian minerals are used to obtain estimates of the likely pressure/temperature conditions of equilibration (5–7 kbar and 700±50 °C) of the various mineral assemblages.

Mineralogical Magazine; June 1976 v. 40; no. 314; p. 541-554; DOI: 10.1180/minmag.1976.040.314.01
© 1976, The Mineralogical Society
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