The Evolution And Geological Significance Of Complex Rock Mass In Xintang City,Cenxi City,Guangxi

In this paper,the author chooses the method of la-icp-ms in situ zircon u-pb dating to determine the time of the igneous rock mass in xintang.The age of the emplacement of granite porphyry was(98-105)Ma,and the age of the porphyry porphyry at xantang granule and the area near the top of zhougong were(100.8,+ 1.8)Ma and(100.0 + 2.0)Ma.Granite porphyry,xantang granule porphyry and porphyry porphyry are the products of late cretaceous magmatic activities in late yanshan.Xintang volcanic rocks(rhyolitic porphyry,the porphyry and volcanic breccia)age was(99.9 + 1.8)Ma,and predecessors' determination of duke of rhyolitic porphyry age is almost the same,as the product of late yanshanian late cretaceous magmatic activity.Through the main analysis(XRF)xintang igneous rock,trace elements(icp-ms analysis)geochemical research,suggests that xintang characteristics show that the main elements of granite porphyry belongs to high potassium calc alkali,aluminum-weak-strong peraluminous granite type I,granite diorite porphyry characteristics show that the main elements of belong to weak peraluminous high in potassium calc-alkaline series I type granite,composition of source rocks is mainly for the partial melting of rock;The main elements of the porphyry granite show that it belongs to the highpotassium calc-alkaline and weak-over-aluminum-strong peraluminous s-type granites,and the source rocks are mainly fused with metamorphic shale and metamorphic sandstone.The main elements of xitang volcanic rock show that it belongs to the series of anglo-ante-rhyolite series,which belongs to high potassium calc-alkaline and quasialuminum-weakly peraluminous-peraluminous series.Xintang porphyry granite and granite porphyry,volcanic rock,less xintang granodiorites have similar geochemical characteristics and consistent isotope age,shows that they are cognate magma,the dynamics of its formation background should be consistent,belongs to the isotope age of early late cretaceous,suggests that at this time in south China with grinding environment.Xintang time is 100 Ma,the body of the complex rock mass are mainly granite porphyry,duke of volcanic rocks,granodiorite,belong to the late yanshanian early cretaceous,the formation of ore deposits and yanshanian magmatic rocks(especially granite porphyry),is close to the origin of yanshan period magmatic rocks provide the source of ore-forming materials,show that the formation of the buddhist blunt pb-zn deposit were probably in the late yanshan,rush to the Buddha pb-zn deposit metallogenic age of the research provides a new clue.