Metamorphic Evolution and Tectonic Implications of Garnet–Bearing Mica Schist in Sumdo High Pressure Belt from Eastern Lhasa Block, Tibet

The garnet–bearing mica–quartz schist of the Sumdo high pressure metamorphic beltfrom the Lhasa block is mainly composed of garnet,muscovite,albite,quartz and minor chlorite,rutile and sphene.Garnet displays obvious zonation where Xpy[=Mg/(Mg+Fe+Mn+Ca)]increases from the core to the mantle,and then decreases in the rim;Xsps[=Mn/(Mg+Fe+Mn+Ca)]declines gradually from the core to mantle,suggesting that garnet compositionThe garnet–bearing mica–quartz schist of the Sumdo high pressure metamorphic beltfrom the Lhasa block is mainly composed of garnet,muscovite,albite,quartz and minor chlorite,rutile and sphene.Garnet displays obvious zonation where Xpy[=Mg/(Mg+Fe+Mn+Ca)]increases from the core to the mantle,and then decreases in the rim;Xsps[=Mn/(Mg+Fe+Mn+Ca)]declines gradually from the core to mantle,suggesting that garnet composition大陆构造与动力学国家重点实验室2Vol.8