An Integrated Study of Layer 3 of the Southwest Indian Ridge

西南印度洋中脊第三层的综合研究

• 批准号: 8907285
• 负责人: Sherman Bloomer
• 金额: --
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-06-01 至 1991-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8907285&HistoricalAwards=false
• 关键词: Integrated; Study; Layer; Southwest; Indian

The oceanic crust is generally thought to grade downward from an extrusive layer of pillow lavas to an intruded sheeted dike complex underlain by gabbros and finally peridotites on the bottom. During Ocean Drilling Program Leg 118, 500 m of gabbro were cored in a single hole, Site 735B, located on a shallow (700 m) wave-cut summit of the eastern transverse ridge of the Atlantic II fracture zone in the southwest Indian Ocean. This is the most complete section of the gabbroic layer yet obtained and provides the opportunity to gain additional understanding of the magmatic processes responsible for the generation of the oceanic crust. This project will develop a structural, metamorphic and igneous stratigraphy, and obtain major, trace and rare-earth chemical analyses on the samples obtained from Site 735B.//

一般认为，洋壳从枕状熔岩的喷出层向下渐变到由辉长岩构成的侵入席状岩墙杂岩，最后是底部的橄榄岩。在大洋钻探计划第118航次期间，在位于印度洋西南部大西洋II断裂带东横脊的浅（700米）浪蚀峰上的735 B号地点的一个单孔中取芯了500米的辉长岩。这是迄今获得的辉长岩层最完整的剖面，为进一步了解造成洋壳形成的岩浆过程提供了机会。该项目将研究构造、变质和火成岩地层，并对735 B地点的样品进行主要、微量和稀土化学分析。