Provenance And Tectonic Setting Of Simian Sediments In Xingguo Area,Jiangxi Province

In this paper,the Sinian sedimentary rocks in the Xingguo region of Jiangxi Province were studied.The zircon U-Pb dating and geochemical analysis were performed in this area to determine the source and tectonic setting.A total of 188 test data were obtained from 3 samples of detrital zircon U-Pb dating,showing 620 Ma(650-550 Ma),965 Ma(1100-900 Ma),1820 Ma and 2465 Ma.Four age peaks.650-550 Ma is the characteristic age of pan-African events.Although this event has no apparent performance on the South China surface,it reflects that the Huaxia block was influenced by pan-African events at that time;1100-900 Ma is the most intense tectonic event in the study area.In the global Grenville orogeny,the detrital zircons mainly come from the magmatic rocks within the Cathaysia Block in this period or the cyclical deposits of the old adjacent formations;1820Ma corresponds to the Palaeoproterozoic magmatic rocks and metamorphic rocks in the northern Wuyishan area;in addition,the age of 2465 Ma The peak corresponds to the growth period of the Cathaysia core.Therefore,the detrital zircon in the 2465 Ma peak range is mainly derived from the recycling deposits of the ancient basement in the Cathaysia Block.In addition,three age data larger than 2800 Ma have appeared in the test data,and they are judged to have originated from the ancient land of the Yangtze Block.Crystallized substrate.The main provenance area of the study area is the Cathaysia block itself,which is the ancient land area in the south and southeast of the study area,and it also accompanies the material that originated from the ancient basement of the Yangtze plate.The analysis and analysis of 17 geochemical samples of the Sinian in the Xingguo area of the Cathaysia block show that all of their original rocks are sedimentary rocks.There are certain changes in the chemical composition of metamorphic sedimentary rocks in different regions,but most of them have obvious light-heavy REE segregation and Eu negative anomaly(?Eu is 0.37-0.65),K2O/Na2 O,Th/Sc,Cr/Zr and other characteristic ratios are displayed.Medium maturity and sedimentary recirculation of the crust.The formation and structure background of Sinian sediments in the Xingguo area of Jiangxi Province are discriminated by the geochemical tectonic discrimination diagrams,showing a variety of tectonic settings of passive continental margins,active continental margins,and continental island arcs,which should be formed on the passive continental marginal environment.Using the discriminant plot of geochemical sources and the comparison of the ratio of characteristic elements to known sources,the source area of Sinian sandstone in the Xingguo area is the Upper Crust Provenance source area,Si-Aluminum source area,and a few source areas.For the basic volcanic rock area.