Intrusive Rock Geochemical Characteristics And Tectonic Significance Of Early Paleozoic In Xinjiang Bayanbulak

Bayinbuluk is located in the intersection of the Middle Tianshan massif and the remnants of the Late Palaeozoic basin of the Albin mountain in the arc basin of the South Tianshan Mountains,and the multiphase magmatic arc in the Middle Tianshan Mountains in the northeast and the carbonate platform in the Albin mountain in the southwest.As the subduction time limit of the South Tianshan ocean basin has been controversial in recent years,and at the intersection of the Middle Tianshan and the South Tianshan Mountains,the product of the magma activity in this area may represent the activity records of the South Tianshan ocean basin and the Middle Tianshan plate in Yili,so the Bayinbuluk intrusive rock is considered as a study.It is of great significance to solve the subduction problem of the South Tianshan oceanic basin.On the basis of the previous research results in the Middle Tianshan and South Tianshan Mountains,the structural evolution of the magma of the Bayinbuluk intrusive rocks is discussed,which provides an important basis for the tectonic evolution of the Middle Tianshan massif and the South Tianshan ocean basin,and the subduction time limit for the South Tianshan ocean basin and the early Paleozoic tectonic evolution of the South Tianshan ocean basin.Provide evidence.The early Palaeozoic intrusive rocks of the Bayinbuluk include the Ordovician and Silurian: the Ordovician intrusive rocks are distributed in a face like distribution,near East-West distribution,and the western region is unconformable in the Silurian brunbruk group,and in the northern East side it is intruded by the late Silurian magma and Permian magma,and the rock mainly consists of quartz diorite,granodiorite and monzonitic granite.The Silurian intrusive rocks are distributed in a surface and near East-West distribution.The western segment is unconformable in the Carboniferous,the Ordovician rock mass,and the south is intruded into the Ordovician rock mass.The eastern and northern sides are intruded by Permian magma.The lithology is mainly composed of quartz diorite,cloud diorite,granodiorite,two long granite,granite and normal.The granite is composed of long granite.Through the LA-ICP-MS zircon U-Pb age determination,the age of the Ordovician biotite two feldspar granite is 462.7±6.2Ma,the age of 463.4±2.8Ma and the age of diagenesis of the quartz diorite 471.5±5.9Ma,indicating the formation of monzonitic granite,monzonitic granite and quartz diorite in the Ordovician Ordovician.In Early Ordovician,the age of diagenesis of Silurian monzonitic granite was 435.5±3.5Ma and 419.7±3.4Ma,the age of diagenesis of Silurian granites was 424.3±2.9Ma and 424.7±3.3Ma,indicating that the formation of the bayenbun Silurian two feldspar was Early Silurian and late Silurian,and Bayinbuluk Silurian granite was formed in the middle chronicles.Stay in the world.The Ordovician and Silurian granitic plutons belong to paralic calc alkaline rocks,showing the characteristics of I type granites,with the geochemical characteristics of the volcanic arc granite,and the magma source area is middle and high pressure environment in the middle and deep parts,and its magma is derived from the crust mantle mixed magma of the lower crust and upper mantle,formed in the subduction and collision environment,and is the South Tianshan Mountain.The oceanic palaeoceanic basin is the product of northward subduction along the southern margin of the Middle Tianshan plate in Yili.The time limit for the initial subduction of the South Tianshan oceanic basin in the bayenbrook area of the Middle Tianshan Mountains is the Middle Ordovician,and the region has the characteristics of becoming younger gradually from west to East.