The Characters Of Bengbu Uplift Metamorphic Basement Metamorphic Attributes, Times And Its Geological Significance In North Anhui

The North China Craton (NCC) as the one of most old Craton in the world, investigators pay a prolong attention to the formation, evolution and constitution. The studying area as the NCC earnest boundary discussed relatively weak. The paper main devoted to reveal the metamorphic characteristics, formation time and confirm the earnest boundary in Bengbu uplift. Therefore, our studying conduct a detailed and systematic research in aspects of field geological investigation, regional metamorphic petrology, microphysiography, thermodynamics and chronology. The main studying is as follows:(1) Constructing the P-T conditions digram and attaining zircon U-Pb chronology from garnet pyroxenite in Fengyang county:According to the research in garnet pyroxenite from Fengyang county recovered that it gone throough five periods metamorphic, which on the basic of P-T conditions. Metamorphic facies is from amp-hibolite to granulite, and turn to amphibolite lately. The results of zircon U-Pb chronology is-1.9Ga,and it is in accordance with the age of collided in NCC earnest plate.(2) Estimateing the peak P-T conditions for garnet-plagioclase amphibolite from Drill ZK02in the south of Mengcheng area:The studying in garnet-plagioclase amphibolite from Drill ZK02, we got the metamorphic P-T conditions in peak. By comparing the P-T condtions, the consequences reveal the metamorphic facies is amphibolite, and it formed in plate.(3) Making sure the earnest boundary of Bengbu uplift:It showed that the granitic gneiss from WEigangcun participated and recorded the events of Dabie orogenic belt subduction and full back in Indosinian. The studying also contained the starting age of Tan-Lu Fault Zone is not earlier than early Jurassic and extent in crosswise. The western boundary of Tan-Lu Fault Zone is localed in the east of Xiaogangcuan and Lianpu, and in west of Weigangcun.