Geochemistry,Detrital Zircon Geochronology And Provenance Aanalysis Of Late Paleozoic Sedimentary Rocks In Qinzhou Area,Guangxi

Qinzhou the Guangxi Zhuang Autonomous Region area is located in the southwest of the Southern China plate,the intersection of Yangtze plate and Cathaysian plate,It is the key part to study the orogenic process of the Yangtze plate and Cathaysian plate.In this paper,the late Paleozoic deep-water sedimentary rocks in the study area are selected as the main research object,this paper focuses on the systematic study of the geochemistry and detrital zircon geochronology of clastic rocks in the siliceous rocks,and discusses its sedimentary environment,Provenance and tectonic background of output,The research results are as follows:(1)The geochemical characteristics show that,the source rocks of the late Paleozoic Clastic Sedimentary Rocks in Qinzhou area are mainly derived from active continental margin and continental arc environment,some may be derived from the passive continental margin environment.The source rocks are mainly sedimentary rocks rich in quartz,some may be intermediate acid volcanic rocks.(2)using LA-MC-ICP-MS zircon U-Pb dating method,In the Guangxi area,Qinzhou,the late Paleozoic siliceous sandstone series in 407~573 Ma(Early Paleozoic),615~997 Ma(Neoproterozoic),1004~1636 Ma(Middle Proterozoic)and 1649~2548 Ma(early Paleoproterozoic Neoarchaean late)four main age groups,There are 4 main regional tectonic thermal events in the source area.(3)A comprehensive analysis of the U-Pb age of detrital zircons from sandstone intercalation in the late Paleozoic siliceous rocks,Huaxia plate is Yunkai area sediment is mainly siltstone late Paleozoic siliceous rocks in the source.Late Paleozoic siliceous rocks of provenance rocks and the upper part of the lower rock has the obvious difference,which is the main sediment source rocks in the early Paleozoic and Proterozoic geological body,and the upper sediment source rock mainly from the Neoproterozoic geological body,early Paleozoic and Proterozoic geological bodies in the source areas become secondary.In addition,the late Paleozoic siliceous rocks of lower peak rocks of Early Paleozoic and Proterozoic two age groups(423.0Ma and 731.5Ma)were higher than that of the upper rock peak corresponding age groups(489.2Ma and 771.6Ma)young.Late Paleozoic siliceous rocks from the bottom to the top of the sediment source is more and more complex,relatively old age that features,Qinzhou Hangzhou with the southwest segment of the Yunkai block at the end of the Caledonian orogeny after rapid and strong uplift erosion become the source region,with the increase of uplift and denudation,deeper source material further,by erosion,transportation and deposition to Qinzhou Hangzhou with the Qinfang basin in the southwest section.(4)Late Paleozoic siliceous rocks detrital zircon siltstone interlayer containing little or lack of Late Paleozoic sedimentary,suggesting that the Qinzhou Hangzhou with the southwest section Qinfang basin in tectonic background stretching in Late Paleozoic Period,the basin should belong to the background of sedimentary basin stretching.