中国合肥盆地新生代火山岩成因岩石学研究

Petrogenesis of Cenozoic Volcanic Rocks in Hefei Basin,China

古新世和渐新世（可能至中新世）玄武岩质岩石的零星露头产在中国东部的合肥盆地中。前者是拉班玄武岩质，而后者是碱性玄武岩质。对它们进行了详细的岩石学以及微量元素和同位素地球化学研究，古新世拉斑玄武岩浆应该来源于一个老地幔楔的部分熔融，而这个地幔楔是由早中生代扬子板块向华北板块之下消减而形成的。自渐新世，中国东部大陆进入了张裂的大陆边缘阶段。该阶段的碱性玄武岩浆可能来源于软流圈。

The scattered outcrops of the Palaeocene and Oligocene(possibly to Miocene)basaltic rocks occur in Hefei Basin in eastern China.The former is tholeiitic, and the later alkalic. The petrology and trace element as well as isotope geochemistry of these rocks have been studied in detail. The Palaeocene tholeiitic magma should be derived from partial melting of an older mantle wedge that formed by the early Mesozoic subduction of Yangtze Plate beneath North China Plate. The eastern China Continent has entered into the stage of rifting continental margin since Oligocene. The alkalic basaltic magma of this stage may be derived from asthenosphere.