Abstract:Study on the isotopic chronology and lithogeochemistry of the Jiangjiatun granodiorite in Tuquan County, Inner Mongolia, indicates that the LA-ICP-MS zircon U-Pb weighted average age for the rock body is 154.8±1.8 Ma, which represents Late Jurassic. The petrological and geochemical data shows the granodiorite, belonging to high-K calc-alkaline series and A-type granite, is characterized by high SiO2 (66.08%-67.80%), rich alkali (K2O+Na2O=7.35%-7.97%), rich Al2O3 (14.5-15.23), poor MgO (1.08%-1.62%), poor CaO (2.05%-3.04%) and low TiO2 (0.56%-0.67%). The REE pattern curves are right-dipping with evident negative Eu anomalies and well LREE fractionation. The primitive mantle normalized trace element spidergrams show distinct negative Sr, Ba and Ti anomalies, depletion of Sr,Ba, Ta and Nb,and relative enrichment of Th,Zr,Hf and Pb. From the above, it is thought that the Jiangjiatun granodiorite is the product of post-orogenic lithosphere extension and shear thinning background affected by the subduction of Paleo-Pacific Plate.
田子龙, 赵庆英, 李子昊, 邱士龙, 李湜先, 郑泽宇. 内蒙古突泉县姜家屯侏罗纪花岗闪长岩年代学及地球化学特征[J]. 地质与资源, 2017, 26(6): 542-551.
TIAN Zi-long, ZHAO Qing-ying, LI Zi-hao, QIU Shi-long, LI Shi-xian, ZHENG Ze-yu. GEOCHRONOLOGY AND GEOCHEMISTRY OF THE JURASSIC GRANODIORITE IN JIANGJIATUN, TUQUAN COUNTY OF INNER MONGOLIA. GEOLOGY AND RESOURCES, 2017, 26(6): 542-551.