Abstract:

Combing the field investigation of mafic microgranular enclaves (MMEs) in granites and the studies of geometry, mineralogy, microtexture and petrochemistry of enclaves, we advanced a model of evolution of MMEs and their relationship to the development of restites produced by partial melting of rockblocks during the insitu melting process. The model reveals that the xenoliths are the precursors of MMEs, and that the xenoliths are the rockblocks coming into the magma from the cover of the magma layer during the melting and the MMEs are the mafic restites of the xenoliths. Variations in type, shape and maficity of MMEs reflect different melting degrees of rockblocks. Biotiterich enclaves are the final products of restite development, which will mix with the host granite magma in further melting, marking the end of the process from rockblock to granite magma.

Key words: granite, insitu melting, mafic microgranular enclave, mafic restite