腾冲新生代火山作用构造—岩浆类型的探讨——一种滞后型的弧火山  

A DISCUSSION ON MAGMA-TECTONIC TYPE OF CENOZOIC VOLCANISM FROM TENGCHONG AREA (YUNNAN PROVINCE)──A NEW TYPE OF POST-COLLISION ARC-VOLCANISM

作　　者：赵崇贺[1] 陈廷方[2] 

机构地区：[1]中国地质大学 [2]四川建材工业学院

出　　处：《现代地质》1992年第2期119-130,共12页Geoscience

摘　　要：腾冲火山群是我国著名的新生代火山群之一。它共分4个喷发期,根据K—Ar同位素地质年龄测定,第一期为2.93Ma,第二期为0.81Ma,第三期为0.31Ma,第四期为0.13Ma。该火山群为典型的钙碱性系列玄武岩—安山岩—英安岩弧火山岩组合。它喷发于晚上新世—晚更新世,但这一时期腾冲地区已为大陆板内环境,它可能与K_2末怒江洋壳俯冲作用有关。因此,腾冲弧火山岩的形成至少在俯冲作用停止以后60Ma,属于一种新的火山作用类型——碰撞后弧火山或滞后型弧火山。Tengchong volcano is one of the famous volcanic groups in Cenozoic in China. Four eruption stages have been reconized. According to the date of K-Ar isochron, the ages of four eruption are 2. 93 Ma, 0. 81 Ma, 0. 31 Ma and 0. 13 Ma respectively. Tengchong vol- canic rocks include basalts. andesites and dacites which belong to a typical calc-alkaline se- ries commonly producing in island-arc tectonic environment. However, before the late Cretaceous collision between two continents andia and Asia-Europe) have been complet- ed and during late Pliocene to Pleistocene, Tengchong area have changed into a continental intra-plate tectonic already. Thus Tengchong arc-volcanism generated after subduction and collision about 60 Ma. We think that post-collision arc-volcanism or delayed arc-vol- canism might be named as a new magma-tectonic type.

关 键 词：新生代 岩浆 滞后型 弧火山 

分 类 号：P588.11[天文地球—岩石学]