地质通报2018，Vol.37Issue(2)：397-410,14.
内蒙古西太仆寺破火山碎斑熔岩与流纹岩LA-ICP-MS锆石U-Pb年龄和地球化学特征
摘要
Abstract
LA-ICP-MS zircon U-Pb dating was carried out for two samples of porphyroclastic lava and rhyolite from the west Taipusi Banner,Inner Mongolia.As a result,their ages were obtained,which are 140.1±0.6Ma and 138.3±0.9Ma,respectively.The results show that all the rocks were produced by magmatic activities in Early Cretaceous. Porphyroclastic lava and rhyolite have the same geochemical features,characterized by high content of SiO2,Na2O+K2O and low CaO,MgO,TiO2and P2O5,and belonging to the high-K calc-alkaline series.A/CNK values of the rocks are from 0.99 to 1.13,suggesting that they are peraluminous.The rocks are characterized by LILE enrichment (Rb, Th, U) and HFSE (Ti, Nb, Ta) strong depletion. They are characterized by enriched LREE patterns with strong negative Eu anomalies(δEu=0.06~0.24),with high TFeO/MgO(5.64~43.29)and 104×Ga/Al(2.96~4.41) ratios,and strong depletion of Ba and Sr.All these geochemical data indicate that they are mainly aluminous A-type granite.Under the regional lithospheric extension,the asthenosphere upwelling and mafic magma underplating provided enhanced heat flux and trig-gered the partial melting of the overlying crust and then produced the porphyroclastic lava and rhyolite.关键词
太仆寺旗/早白垩世/碎斑熔岩/流纹岩/华北北缘/A型花岗岩/LA-ICP-MS锆石U-Pb测年Key words
Taipusi Banner/Early Cretaceous/porphyroclastic lava/rhyolite/the northern margin of North China Craton/A-type granite/LA-ICP-MS zircon U-Pb dating分类
天文与地球科学引用本文复制引用
曹光跃,刘哲,薛怀民..内蒙古西太仆寺破火山碎斑熔岩与流纹岩LA-ICP-MS锆石U-Pb年龄和地球化学特征[J].地质通报,2018,37(2):397-410,14.基金项目
中国地质调查局项目《显生宙重大岩浆事件与岩浆岩试点填图》(编号:121201102000150021) （编号:121201102000150021）
