摘要
同位素年代学、岩石学、矿物化学和岩石地球化学特征研究表明,羌塘错尼地区火山岩可以划分为3套岩石组合:1高钾钙碱性火山岩(44Ma～38Ma);2钾玄岩质火山岩;3强碱性火山岩(34Ma～19Ma)。3套火山岩均是大陆碰撞造山后期岩浆作用的产物,始新世以来,随着该区由碰撞、挤压作用发展到出现走滑,应力环境由挤压转变为张性,导致依次喷发高钾钙碱性火山岩、钾玄岩质火山岩和强碱性火山岩。强碱性火山岩的地球化学特征暗示了岩浆源区受到过地幔流体的强烈交代作用。
The studies of geochronology,petrology,mineralogical chemistry and petrochemistry showed that the Cenozoic volcanic rocks from the Cuoli Lake of the Qiangtang area can be classified into three series.They are high-potassium calc-alkaline series (44 Ma^38 Ma),shonshonite series and strong alkaline series (34 Ma^19 Ma) respectively.These Cenozoic volcanic rocks formed in post-collision tectonic environment.During the process of transition from compressional to tensile environments,high-potassium calc-alkaline,shoshonitic and strongly alkaline series formed,successively.The geochemical characteristics of ultrapotassic rocks impliled an enriched mantle source metasomatized by subduction-related fluids.
出处
《矿物岩石》
CAS
CSCD
北大核心
2005年第2期27-34,共8页
Mineralogy and Petrology
基金
国家973计划项目"印度与亚洲大陆主碰撞带成矿作用"下属课题"藏东缘兰坪与昌都大型复合盆地铜铅锌银多金属成矿作用对比研究"(编号2002CB412607)
关键词
青藏高原
藏北
羌塘
错尼
火山岩
岩石学
地球化学
新生代
Qinghai-Tibet plateau
northern Tibet
Qiangtang
volcanic rock
petrology
geochemistry
Cenozoic
Cuoli Lake
