Petrogenesis of metaophiolitic granulites from SE Anatolia

Abstract

Metaophiolitic rocks exposed in southeastern Anatolia record the evolution of the Southern Neotethys ocean and Tauride plate margin. The Berit metaophiolite contains granulite and amphibolite facies rocks metamorphosed in the middle Eocene. Granulite facies metagabbros occur as pods hosted by folded amphibolite. The pods are texturally complex, and contain coronas and symplectites. Clinopyroxene and garnet coronas around orthopyroxene indicate prograde metamorphism from intermediate- to high-pressure granulite facies. Pseudosections indicate that the granulites equilibrated at 700-900 °C and 1.1-1.5 GPa. Corundum- and kyanite-clinopyroxene symplectites suggest rapid isobaric cooling of ~150 °C at ~1.2 GPa following the thermal peak. Hornblende-plagioclase thermobarometry of the amphibolites indicates retrograde hydration of the granulites to 615-700 °C and 0.5-0.8 GPa. Together, textural evidence and pseudosections indicate an anticlockwise P-T path which is attributed to loading during the development of a magmatic arc. Following cooling, extension of the arc exhumed the granulites and produced the host amphibolite.