广东三水盆地古俯冲带地幔源岩石的年代学与Nd-Sr-Pb同位素证据  

GEOCHRONOLOGY OF AND Nd-Sr-Pb ISOTOPIC EVIDENCE FOR MANTLE SOURCE IN THE ANCIENT SUBDUCTION ZONE BENEATH SANSHUI BASIN, GUANGDONG PROVINCE, CHINA

作　　者：朱炳泉[1] 王慧芬[1] 毛存孝[1] 朱乃娟 黄荣生[1] 彭建华[1] 蒲志平 

机构地区：[1]中国科学院地球化学研究所广州分部,510640

出　　处：《地球化学》1991年第1期27-32,共6页Geochimica

基　　金：国家自然科学基金(4870186)

摘　　要：广东三水盆地火山岩岩石化学资料表明为具岛弧特征的拉斑-钙碱性岩系。K-Ar年龄为43-64Ma,属早第三纪。Nd-S-Pb同位素相关构成两个二元混合趋向,表明其源区为雷琼亏损地幔源与海水和蚀变俯冲沉积物相混合。这一结果表明华南大陆内存在着古俯冲带。它是由中国南部不同地体在缝合过程中产生的。The available petrochemical data indicate that volcanic rocks in the Sanshui basin of Guangdong Province are characteristic of the island-arc tholeiite-calc-alkaline series. Their K-Ar ages range from 43 to 64 Ma, corresponding to Early Tertiary. The Nd-Sr-Pb isotopic correlations give two binary mixing trends, indicating a mixed source of Leiqiong depleted mantle, seawater and altered sediments pertaining to subduction. Our studies have confirmed the existence of an ancient subduction zone beneath the South China continent, which is considered to have resulted from the suturing of various terrains in southern China.

关 键 词：火山岩 岩石 古俯冲带 Nd-Sr-Pb 

分 类 号：P588.14[天文地球—岩石学]