Study On The Cause And Deformation Features Of Quartz Veins In The Late Paleozoic Tectonic Schist,in Gangmari Region,Tibet

The study area is located in the Tibet Autonomous Region in northern bindingsite is located in the Qiangtang Basin hinterland, North Qamdo plate and Qiang SouthBaoshan plate two plates. In this paper, the distribution of tectonic schist is moreextensive, throughout the maps in most parts of central and western. The era oftectonic schist is ainly Carboniferous–Permian, Tectonic schist mainly experiencedthree deformation and two metamorphism. S2is the rgional foliation. Themetamorphic minerals such as chlorite, sericite are distributed along the foliation S1and S2. The fe-sericite distribution in the S3foliation.First of toughness under the condition of shear deformation, the formation ofshear crenulation cleavage S1, S1is a penetrative regional foliation. in the beat withthe original bedding S0nearly parallel. During which the secretion of syntectonicquartz veins, and the occurrence of a strong flexible flow fold phenomenon. Thesecond phase of deformation is the level of shrinkage, development of regionalpenetration foliation S2. that is axial typecrenulation cleavage. The third phase ofdeformation at the outcrop scale the performance of the thegeniculate fold theformation of the foliation S1, S2, mutually perpendicular to the fold axis F3and F2.With the deformation and metamorphism of tectonic schist, quartz veindevelopmentin the macro quartz porphyroclastic system, syntectonic quartz veins, softflow folds,sharp edges, folds, rootless hook folds typical structural phenomena; Showthe eye structure, the book structures, mica fish structure in the micro. Regardless ofmacro-and micro-tectonic schist and quartz veins have shownsignificant foliationreplacement phenomenon, reflect and validate the regionaldeformation andmetamorphic features.In order to study the formation conditions of quartz veins, I fluid inclusionsthermometry experiments.The experiments selected quartz samples are syntectonicquartz veins formed bytectonic schist of the study area with the same period offoliation S2, more fresh, a good representative. Test results for inclusions trappedwhen the temperature of350°C,that is Homogenization temperatures of fluid inclusions; Estimate the trapping pressure is225MPa. Syntectonic liquid inclusions inthe chemical secretion of the body temperature data can be used as the tectonicdeformation phase analysis indicators, resulting quartz vein formationtemperature andpressure conditions is T=350°C, P=225MPa. The results reflect metamorphicfacies in the formation of quartz veins reached a low greenschist facies. This isconsistent with the inference made before by the macro structure schist andquartzveins deformed metamorphic characteristics, Verify the test results of the inclusionsunder a microscope observations of tectonic schist and quartz veins.According to field observations and experimental data and experimental resultsof Xiao Huayun, I believe that the tectonic schist of the study area, extensivelydeveloped quartz veinssyntectonic secretion crystalline pulse, the formationmechanisms of quartz veins is closely related shear toughness with thesubstancedissolved, migration, recrystallization.