SIMPLE MIXING,AFC MIXING AND ISOTOPE DATA EXPLANATION OF GRANITOIDS
Chen Jiangfeng (Department of Earth and Space Sciences,University of Science and Technology of China,Hefei,230026)
Mixing Processes can be divided into two main types, two-end member simple mixing and assimi- lation coupled with fractional crystallization (AFC) -type mixing, based on Sr, Nd and Oisotopic system- atics. Generally, simple mixing is represented by magma mixing, isotope exchange or remelting of a mixture made of mantle-derived and crustal materials. The AFC mixing is represented by a process in which mantle-derived magma assimilates crustal country rock and crystallizes in the same time, which is most clearly shown when the process happens in the shallow level of the crust. It is important to distinguish different mixing machanisms in understanding petrogenesis of granitoids.