欢迎访问《高校地质学报》官方网站,今天是
分享到:

J4

• 文章目录 • 上一篇    下一篇

杭州河上地区新元古代火山岩与侵入岩的岩浆同源性

卢成忠   

  1. 浙江省 地质调查院,杭州 311203
  • 收稿日期:2007-12-20 修回日期:2007-12-20 出版日期:2007-12-20 发布日期:2007-12-20

Magmatic Consanguinity of Neoproterozoic Volcanic and Intrusive Rocks in Heshang Area, Hangzhou Region

LU Cheng-zhong   

  1. Zhejiang Research Institute of Geology, Hangzhou 311203, China
  • Received:2007-12-20 Revised:2007-12-20 Online:2007-12-20 Published:2007-12-20

摘要: 杭州河上地区是浙西北上元古界上墅组火山岩发育的典型地区,同时还发育新元古代辉绿岩和碱长花岗岩板状复合浅成侵入体。火山岩与侵入岩在空间上密切共生,形成时间相近,皆为晋宁晚期构造岩浆活动的产物。火山喷发并伴随的岩浆侵入经历了两个阶段,每个阶段的火山岩与侵入岩在岩石类型、岩石化学和地球化学方面具有相似性或一致性,稀土元素分布型式基本一致,说明每个阶段的火山岩与侵入岩来源于同一岩浆源,均是同源岩浆活动的产物。第一阶段上墅组基性火山岩与次坞辉绿岩体起源于亏损程度较低的地幔,或来源于亏损地幔的岩浆受到陆壳物质的混染;第二阶段上墅组酸性火山岩与道林山碱长花岗岩体可能起源于地壳中既含有基性地壳组分和又含有酸性地壳组分的源区的部分熔融。

Abstract: The Heshang area of Hangzhou region in northwest Zhejiang is a typical place where the Upper Proterozoic volcanic rocks of Shangshu Formation outcrop. In this area, there is also observed the occurrence of Neoproterozoic diabase and hypabyssal, composite intrusive rocks of alkalic feldspar granite. The volcanic rocks and intrusive rocks have close spatial association and close age. They are both products of tectono-magmatic activities in Late Jinning period. The magma eruption and intrusion could be divided into two stages. The rocks formed in each particular stage have similar or identical characteristics in their rock types, petrochemistry and geochemistry. These features indicate that the volcanic and intrusive rocks in each stage have the same magma origin. The basic volcanics in Shangshu Formation and Ciwu diabase, formed in the first stage, were derived from the less-depleted mantle or the magma with the origin of depleted mantle contaminated by continental crust. The acid volcanics in Shangshu Formation and Daolinshan alkalic feldspar granite, formed in the second stage, might be derived from partial melting of crust sources consisting of both basic and acid constituents.