Geochemical Characteristics and Tectonic Significance of Triassic Granite from Taer Region, the Nort

• 作 者: HUANG Jianguo YANG Ruidong YANG Jian CUI Chunlong
• 机 构: School of Environment and Resource, Southwest University of Science and Technology, Mianyang 621010,
• 出 处: The First Joint Scientific Meeting of Geological Society of
• 发表日期: 2013年11期
• 关键词: Triassic granite S-type granite zircon U-Pb age tectonic significance northern m

　　Late Hercynian-early Indosinian(Triassic)granite is widely distributed around the Taer region of the northern margin of West Kunlun.The rock mass is mainly composed of calc-alkaline porphyroid biotite adamellite and characterized by Si02-rich,high-Ca,moderate-alkaline,and strongly peraluminous attributes,and relatively low EREE with LREE enrichment and a moderate Eu anomaly.As shown in the trace element spider web diagram,distinct peaks appear for Th,La,Nd,and Zr and clearly low values appear for Ba,Nb,Sr,P,and Ti.Further,compared with the primitive mantle,Rb/Sr and RbfBa are considerably higher and Nd/Th and Nb/Ta are relative low,all falling into the scope of the crust-origin rocks,indicating the characteristics of the crust-origin S-type granite.The rock masss zircon U-Pb isotopic age is determined to be 235.7± 3.9 Ma.On the basis of the age data,spatio-temporal location,lithology,and geochemistry of the rock mass,we conclude that the formation of the rock mass is closely related to the strong compressional orogenic movement(240Ma)of the Tianshuihai terrane and the South Kunlun terrane.The rock mass is the product of the collision orogenic movement.However,distinct differences are observed between the studied rock mass and the synorogenic Bulunkou rock mass.which may be caused by the different collision strength and different positions with respect to the collision zone.