摘要
拉萨地块西段分布有大面积的古近纪火山岩,蕴含着丰富的地质信息。文章对措勤地区典中组火山岩年代学、地球化学的研究表明,典中组火山岩岩浆活动在晚白垩世晚期已经开始,之后逐步向东迁移,时间上一直持续到古新世。印度板块与亚洲板块碰撞可能是从西段开始的,之后逐渐向东碰撞过渡。典中组火山岩岩浆形成的过程中发生了部分熔融作用,且在成岩过程中发生了混合作用;典中组火山岩是岛弧型俯冲向碰撞过渡过程中产生的具有岛弧或陆缘弧特点的火山岩。
In the west Lhasa block is distributed large areal Paleogene volcanic rocks which contain abundant geological information.Researches on chronology and geochemistry of volcanic rocks of Dianzhong formation in Cuoqin area show that magmatism of the formation started from Late Cretaceous period then moved eastward and continued temporally until Paleogene epoch.Collision of India plate and Asia plate began at the west part and propagated eastward.During formation of volcanic rocks of Dianzhong formation partial melting occurred and mixture of the magma and the melted materials followed.Volcanic rock of Dianzhong formation is characteristic of island arc volcanics or marginal arc volcanics of continent generated during transformation from island subduction to collision.
出处
《地质找矿论丛》
CAS
CSCD
2014年第2期262-267,共6页
Contributions to Geology and Mineral Resources Research