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Abundant metabasites occur in highly deformed granitic and migmatitic gneisses as blocks and lenses of tens of meter size around the Haiyangsuo area, northeast part of Sulu UHP belt, eastern China. They comprise garnet-pyroxene granulites, eclogitized granulites and amphi-bolites. Their protolith compositions were mainly olivine tholeiite and quartz tholeiite, and show variation from Mg-rich to Fe-rich component as tholeiitic cumulates. Pearce’s element ratio slopes suggested that protolith of these rocks were comagmatic, and generated from a primary magma by fractional crystallization of plagioclase, olivine and clinopyroxene. The crystallization differentiation has also been evidenced by trace elements, such as parallel REE patterns, Ni vs Ce variations, Sr increasing depletions, although the large ion lithophile elements (LILE) were modified to different extent during metamorphism. Trace element composition and Nd isotopes indicate a depleted mantle origin for these rocks. But they are not likely to b
Abundant metabasites occur in highly deformed granitic and migmatitic gneisses as blocks and lenses of tens of meter size around the Haiyangsuo area, northeast part of Sulu UHP belt, eastern China. They comprise garnet-pyroxene granulites, eclogitized granulites and amphi-bolites. Their protoliths compositions were mainly olivine tholeiite and quartz tholeiite, and show variation from Mg-rich to Fe-rich component as tholeiitic cumulates. Pearce’s element ratio slopes suggested that protolith of these rocks were comagmatic, and generated from a primary magma by fractional crystallization of plagioclase, The crystallization differentiation has also been evidenced by trace elements, such as parallel REE patterns, Ni vs Ce variations, Sr increasing depletions, although the large ion lithophile elements (LILE) were modified to different extent during metamorphism. Trace element composition and Nd isotopes indicate a depleted mantle origin for these rocks. But they are not likely to b