大别山地区榴辉岩的特征矿物研究

大别山地区的“大别群”,在湖北和安徽境内呈近东西—北西西向出露。这套变质杂岩为一套蓝闪片岩相、铁铝榴石角闪岩相、麻粒岩相和榴辉岩相所组成。它们不整合伏于浅变质岩系之下。“大别群”的时代,经湖北区测队用锆石铀-钍-铅定年法获得四组年龄数值,其变化在1952—2424万年之间,采

STUDY ON THE MINERALOGY OF ECLOGITES IN THE DABIESHAN

The tectonic environmints of Dabieshan have long been discussed a mong geologists. In 1976, We raised the opinion that there perhaps may be a "f ossil subduation" trending E. W. Recently we have system a tically studied the minerals from this metamorphic terrain of Dabie group in Hubei and Anhui. and their P-T Conditions. The lower proterozoic Wuhe group in Anhui is also considered.Phanerozoic formation discordantly overlies on these metamorphosed terrains. The radioactive age of zircon is Machao group are 1328, 1578 my., the age of biotite in Wuhe group are 1650, 1767, 1810 my. High P-Low T minerals, such as omphacite, garnet, crossite, barroisite, phengite, of barroisite-ecologite, amphobole-schist and gra.nulite facies are the main subjects of this study. According to the study of minerals in Dabieshan metamorphic terrain we suggest that the Dabieshan was a plate boundary of paleoceanic plate in finning cycle Low T-High P metamorphic belt was found in the southern side of the mountain, i. e., the oceanic side. Pressure de- creased northward.