Journal article

Cr-pyrope garnets in the lithospheric mantle. I. Compositional systematics and relations to tectonic setting

WL Griffin, NI Fisher, J Friedman, CG Ryan, SY O'Reilly

JOURNAL OF PETROLOGY | OXFORD UNIV PRESS | Published : 1999

Abstract

Chrome-pyrope garnet is a minor but widespread phase in ultramafic rocks of the continental lithosphere; its complex chemistry preserves a record of events related to fluid movements in the mantle, including melt extraction and metasomatism. We have examined the major-element and trace-element composition of >12 600 Cr-pyrope (Cr2O3>1 wt %) xenocrysts in volcanic rocks to evaluate their compositional ranges and interelement relationships. Samples have been divided into three major groups (Archon, ≥2.5 Ga; Proton, 2.5-1 Ga; Tecton, <1 Ga) depending on the age of the last major tectonothermal event in the crust penetrated by the host volcanic rock. Relative depths of garnets within each sample..

View full abstract

University of Melbourne Researchers