青海万秀寺早白垩世火山岩特征及时代探讨  

The character and age of volcanic rock of Early Cretaceous epoch in Duofutun area of Zeku,Qinghai

作　　者：杨延兴[1] 史连昌[1] 谈生祥[1] 刘荣[1] 

机构地区：[1]青海省地质调查院,青海西宁810012

出　　处：《青海大学学报（自然科学版）》2011年第5期49-56,79,共9页Journal of Qinghai University(Natural Science)

基　　金：国家地质大调查项目(1212010510408)

摘　　要：在青海泽库县多福屯乡地区发育一套钠质碱性基性火山岩系,为了探讨该套火山岩的构造环境,在野外实地调查中,详细划分了其岩石组合类型,并通过采集大量的样品,从岩石学、岩石地球化学、形成时代等方面,对火山岩进行了综合分析研究。结果表明:该火山岩似OIB性质的陆内火山岩,源区具有DM与EMⅡ混合特点,取得的同位素成果为116～121Ma(U-Pb),时代属早白垩世。经过详细的调查研究,将该火山岩建造命名为麦秀群(K1 M)多禾茂组,其形成环境为陆内拉张环境下(大陆裂谷)的岩浆活动产物。A sodic alkaline basic volcanic rock set outcrops in Duofutun area, Zeku County, Qinghai Province. In order to explore the tectonic setting of volcanic units in the field survey, the combination of rock types was classified. A large number of samples were collected. From the petrology of volcanic rocks, geochemistry and formation age of these aspects, a comprehensive analysis was carried out. The results show that the volcanic nature of the land within the OIB like volcanic source has mixed characteristics of DM and EMII. Results obtained by isotope 116 - 121Ma （U -Pb） indicates the volcanic rock set belongs to an Early Cretaceous age. It is the outcome of continental rift valley. The rock association is denominated for Duohemao Formation, Maixiu Group.

关 键 词：青藏高原 早白垩世麦秀群多禾茂组火山岩 时代 特征 

分 类 号：P56[天文地球—构造地质学]