【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。更多还原

【Abstract】 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.更多还原