五河地区紫苏麻粒岩岩石学特征初探

ON THE PETROLOGIC CHARACTERISTICS OF HYPERSTHENE GRANULITE IN THE WUHE AREA

安徽蚌埠—五河地区的晚太古宙蚌埠群西堌堆组绿岩内发现了紫苏麻粒岩(暗色麻粒岩),其上、下发育有数十米厚的麋梭岩。这说明该区有高级变质的线状区域动力热流变质作用的麻粒岩相岩石存在。此发现对本区晚太古宙地壳形成的历史及其变质演化过程的研究,提供了新的重要的参考资料,并对以往研究者认为本区属中低级变质的角闪岩相的结论进行了修正。

Hypersthene granulite(melagranulite)was found in the late Archean greenstone of West Gudui Formation of Bengbu Group.Above and below the greenstone there are tens of meters mylonites,which suggests that this area has undergone high-grade linear regional thermodynamic meta- morphism.The discovery provides new important reference data to the study of the forming history and metamorphic evolution process of the late Archean crust in the studied area.Based on the discovery,the old view that the metamorphic rocks in the area are products of amphibolite facies of middle-low grade metamorphism is revised.