Proto-basin And Tectono-paleogeographic Evolution Of The Lower Paleozoic In The Southern Part Of South China

On the basis of comprehensive analysis of previous research results,in this paper, the Northern Guangxi Early Paleozoic strata, Huajiang area of stratigraphic sequence and rock composition,sedimentary facies and sedimentary environment, tectonic deformation,rock and element geochemical studies and isotopic geochronology, made the following main knowledge and progress:The petrographic and geochemistry research of the early Paleozoic shows that the original rock of palaeozoic era in north Guangxi as the terrigenous clastic sedimentary rocks, display as the distant shore shale content high reductive environment.Mainly for turbidity current and deep sea facies sedimentary facies in the study area, the qingxi period in the Cambrian, the flow of the deep-water slope facies, the bianxi period, sedimentary environment was simila with the qingxi basic, but there is no occlusion stranded environment.baidong formation are limestone reflects shallow tidal-flat sedimentary environment, haungai formation reflect the depositional environment was shelf sea quiet reduction, ping group reflect the neritic bathyal environment.Vertical performance for deep-water slope-shallow sea restricted platform- neritic shelf sedimentary evolution process.The louditang formation mainly volcanic breccia and tuff, rocks of low compositional maturity and structural maturity, poor sorting rounded, showed that volcanic clastic rock produced in basin slope zone, by the trigger sexual geological processes, rapid handling accumulation. First time obtain the tuff zircon age 415±5Ma, and have bigger difference between the Cambrian and Ordovician stratigraphic age.Geochemical analysis showed that north guangxi region was passive continental margin in the Early Paleozoic.