Pyroxenes in Altered Volcanic Rocks, Glenrock Station, NSW, Australia

R. Offler
Department of Geology, The University of Newcastle, NSW, Australia, 2308

Summary: Microprobe analyses of relict pyroxenes in meta-basalts from thrust slices of the Peel fault zone, Glenrock Station, NSW, demonstrate that the majority of these rocks have a tholeiitic affinity. Those of Ordovician to L. Devonian(?) age in the upper thrust slices show a greater Fe-enrichment, and lower wollastonite, Al and Ti contents than their Devonian counterparts in the lowest thrust sheet. The pyroxene data also indicate that some rocks are geochemically transitional between tholeiitic and alkaline magmas. The relict pyroxenes in metadolerites emplaced in the Devonian sequence show that these rocks are transitional to tholeiitic in character and that they appear not to be consanguineous with the metabasalts.

Mineralogical Magazine; December 1979 v. 43; no. 328; p. 497-503; DOI: 10.1180/minmag.1979.043.328.09
© 1979, The Mineralogical Society
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