南马里亚纳海槽岩石学特征  

Petrological Features of the South Mariana Trough

作　　者：陈穗田[1] 吴世迎[1] 张德玉[1] 

机构地区：[1]国家海洋局第一海洋研究所

出　　处：《黄渤海海洋》1994年第2期23-31,共9页Journal of Oceanography of Huanghai & Bohai Seas

摘　　要：南马里亚纳海槽岩性比较复杂：有玄武岩，根据标准矿物组合，进一步划分为碱性玄武岩，橄揽拉斑玄武岩和石英拉斑玄武岩；火山碎屑岩，包括凝灰岩和角砾凝灰岩；以及方辉橄榄岩．大部分玄武岩样品是距今五百万年以后形成的，个别岩石样品的形成年龄为八百万年左右．不同类型的玄武岩是含Ｈ２Ｏ的地幔岩块在底辟上升过程中，局部熔融、分离的产物；火山碎屑岩是火山喷发的火山灰、火山砾被水化学分解的物质胶结而成；方辉橄榄岩是地幔岩浆底辟上升直接侵入结晶的产物．Lithology of the South Mariana Trough is complicated. Its rocks include basalts,pyroclastic rocks and harzburgite. Based on the standard mineral association,the basalts can be subdivided into alkali basalt,olivine tholeiite and quartz tholeiite,and the pyrocalastic rocks includes tuff and brecia tuff. Most of the basalts were formed 5 Ma ago,with some formed 8 Ma ago. The different types of basalts are the products formed by locally melting and differentiating mantle rock mass containing H2O during the diapiric uprising. The pyroclastic rocks are the product formed by cementation of volcanic ashes and brecia after chemical dissolution through seawater. The harzburgite is a product formed by direct intrusion and crystallization of mantle magma during the diapiric uprising.

关 键 词：马里亚纳海槽 岩石学 海槽 

分 类 号：P736.14[天文地球—海洋地质]