R8: Metamorphic rocks and tectonics

[R8P-02] Estimation of P-T path of garnet peridotite from a northeastern part of the Su-Lu region, China

「発表賞エントリー」

*Yu Oikawa^1,2, Daisuke Nakamura¹, Takao Hirajima², Tomoaki Morishita³, Akihiro Tamura³, Hajime Yamane¹ (1. Okayma Uni. Sci., 2. Kyoto Uni. Sci., 3. Kanazawa Uni. Sci.)

Keywords:garnet peridotite, Su-Lu region, Chijiadian

We estimated P-T path of garnet peridotite from a northeastern part of the Su-Lu region of China. A garnet megacryst in the studid sample has Cr-rich rim. Cr contents discontinuously increase at the rim. Applying thermobarometers, pairs of the Cr-rich rim and matrix Opx gave higher P-T (4.1GPa, 770 ºC) than those of its core and Opx inclusions (1.0GPa, 660 ºC). Thus, this garnet megacryst grew at relatively low T and shallow levels, and then the Cr-rich rim was formed by rapid compression. In addition, we interpret this Cr-rich rim has been also affected by metasomatic fluid infiltration.