云和盆地早白垩世双峰式火山岩特征

本文从岩石学、岩石化学、微量元素及稀土元素等方面，对云和盆地早白垩世馆头组火山岩特征进行了论述，并对其形成环境及成因作了探讨．认为该套火山岩由基性岩及酸性岩构成，缺少SiO2含量在53．17％～68．57％的中性岩，是一套典型的双峰式火山岩组合。指出盆地内火山岩为拉张构造背景下形成，其基性岩和酸性岩具有不同源区，前者源于部分上地幔融熔物质（受陆壳物质混染）；后者来自部分地壳融熔的产物。

FEATURES OF LOWER CRETACEOUS BIMIDAL VOLCANIC ROCKS IN ZHEJIANG YUNHE BASIN

The volcanic rocks of lower cretaceous Guantou formation in south-west Zhejiang consist ofbasic rocks and acid rocks, without neutral rocks, of which silica are between 53. 17% and 68.57%. It is a set of. typical bimedal volcanic rock assemblage. On the basin of petrology, Petrc-chemistry, microelement and rare earth element, this paper expounded the features of the volcanic rocks, and discussed its forming environment and genesis.