The Provenance Analysis And The Geological Significance Of The Cameng Rock Formation With Metamorphic Sandstone In Rongma Area, North Tibet

The study area is located in Rongma area, North Tibet, which is also in the hinterland of the Southern Qiangtang. Accretion complex in the study area is a set of non-smith strata, the overall disorder and partial order is its obvious characteristics. In this paper,I will force on the Cameng rock Formation metamorphic sandstone of Xueshuihe Rock Group, and mainly discuss the provenance analysis of the Cameng rock Formation and the formation of the tectonic environment.To explore the properties of Cameng rock formation, the author fielded investigation and measured the typical profile, collected a large number of samples to test and analyze. According to the test data,the auther analyzed and verified the provenance.This paper analysis of provenance worked through the petrography, geochronology, geochemistry and zircon matrix composition.The morphology analysis and chronology of Detrital zircon explained that sedimentary cover layer certainly received the materia from the early Paleozoic strata,A large number of age in the Cameng rock formation recorded the age of the Pan African tectonothermal event, suggesting that detrital material was from the metamorphic basement of Gondwana, the conclusions supported the understanding of the southern Qiangtang block belonging to the Gondwana.The Dickinson graphy for the skeleton Mineral composition of metamorphic sandstone shows that the provenance was mixture source of the continental plate, the magmatic arc and recyclic orogenic zone.According to the geochemical element data, a variety of tectonic discrimination diagrams showed that the structure type of the source region are mainly passive continental margin.Comprehensive study shows that the source region of the Cameng rock formation went through the Pan African tectonic magmatic thermal event. Before the Permian, the region has entered Paleo Tethys ocean subduction period, the sand slate in the Xueshuihe Rock Group,which has the features of Submarine fan deposition, Served as the matrix of the mixed rock. The early Paleozoic strata and high-pressure metamorphic rocks(blueschist, eclogite, etc.) in the form of block mixed into the sand slate matrix. The Paleo Tethys was in the subduction collision stage During the Late Permian and Triassic, eventually, the accretion complex with typical features was formed.