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Blueschist and eclogite in tectonic melange, Port Macquarie, New South Wales, Australia

Published online by Cambridge University Press:  05 July 2018

D. J. Och*
Affiliation:
Environmental Sciences, University of Technology, Sydney, NSW 2007, Australia
E. C. Leitch
Affiliation:
Environmental Sciences, University of Technology, Sydney, NSW 2007, Australia
G. Caprarelli
Affiliation:
Environmental Sciences, University of Technology, Sydney, NSW 2007, Australia
T. Watanabe
Affiliation:
Earth and Planetary Sciences, Graduate School of Science, Hokkaido University, Sapporo, Japan, 060
*

Abstract

The Rocky Beach Metamorphic Melange contains metre-scale phacoids of high-P low-T metamorphic rocks embedded in chlorite-actinolite schist. The phacoids include eclogite, glaucophane schist and omphacitite and provide evidence for four episodes of metamorphism with mineral assemblages: M1 = actinolite-glaucophane-titanite-apaite, M2 = almandine-omphacite-lawsonite ±quartz, M3 = phengite- glaucophane-K-feldspar-quartz, and M4 = chlorite-actinolite-calcite-quartz-titanite-white mica ± albite ± talc. M1-M3 occurred at a Neoproterozoic-Early Palaeozoic convergent plate boundary close to the eastern margin of Gondwana. Peak metamorphic conditions were attained during the static phase M2, with temperatures of ~560°C and pressures in excess of 1.8 GPa, equivalent to a depth of burial of at least 54 km.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2003

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Footnotes

Present address: Douglas Partners Pty Ltd, 96 Hermitage Rd, West Ryde, NSW 2114, Australia

Deceased

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