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岩石学报 2004
Complex zoning texture in plagioclases from the quartz diorite enclave in the Putuo granitic complex, Zhejiang province: record of magma mixing
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Abstract:
Three types of plagiaclases with distinel zoning texture have been recognized from the recent investigation of the quartzdiorite enclave at Putuo. Zhejiang Province: normally zoned plaginclase, sieve-textured plagioclase and "reverse-zoned" plagioclase. Based on the evidences from tire components and textures of the plagioclase, the following scenario about the magma evolution is tentatively suggested. The initial basic magma in the deeper chamber injected into the host acid magma, in which the crystallization of oligoclase had already started. Then the sieve texture was formed after the plagioclases were incorporated into the mafic magma, In the later stage of the mixing process, the rough-interface wag produced between acid plagioclase and melt. In addition, a normal zone was directly formed from the equilibrium mixing magma as a single crystal or the mantle. By comparing with the special sieved plagioclases in Pingtan complex, we suggest that the textures and chemical compositions of plagioclases record the features of magma sources and reflect the history of the magma evolution.