福建德化蒲洋、浦城仙阳地区早古生代埃达克质岩成因探讨及其地质意义  

Genesis of Early Paleozoic Adakic Rocks from Dehua Puyang and Pucheng Xianyang in Fujian Province and its Geological Implications

作　　者：周小栋 Zhou Xiaodong(Fujian Institute of Geological Survey,Fuzhou,350013)

机构地区：[1]福建省地质调查研究院,福州350013

出　　处：《福建地质》2024年第2期87-99,共13页Geology of Fujian

基　　金：福建省地质矿产勘查开发局科研项目“福建中-北部马面山增生杂岩调查及其大地构造意义研究”。

摘　　要：华南加里东造山作用的类型仍存在争议,焦点集中在是否存在加里东期的大洋俯冲造山作用。根据福建德化蒲洋花岗闪长岩和浦城黄墩、仙阳等地的二长花岗岩年代学,岩石地球化学特征研究认为,岩石具埃达克质岩特征,成岩年龄为450~455 Ma,侵位时间与早古生代华夏地块西南部的云开造山运动的俯冲时限(460~440 Ma)吻合,结合区域资料,认为是大洋俯冲板片部分熔融成因,为该时期华南板块存在洋板块俯冲造山作用提供了重要证据,且指示初始俯冲时限不晚于455 Ma。The mechanism of Caledonian orogeny in South China is still controversial.The main argument focuses on the issue that whether there existed Ocean subduction orogeny in the Gallidon period.According to the chronology and geochemical characteristics of monzonitic granites from Puyang granodiorite in Dehua,Fujian Province,and Huangdun and Xianyang in Pucheng,Fujian Province,the rocks have the characteristics of Adakic rocks,and the diagenetic age is 450~455 Ma.Their emplacement time were well corresponding to the subduction stage of the Yunkai orogeny in the southwestern part of Cathaysia block during the Early Paleozoic(460~440 Ma).Combined with the regional data,it is believed that the origin of oceanic subduction plate partial melting,which provides important evidence for the existence of oceanic subduction orogeny in the South China Plate during this period,and indicates that the initial subduction time is no later than 455 Ma.

关 键 词：早古生代 埃达克质岩 洋板块俯冲 加里东造山 锆石U-PB定年 武夷地区 

分 类 号：P548[天文地球—构造地质学] P588.12[天文地球—地质学]