Seismic Structure of Ultramafics at Shallow Crustal levels from On-Bottom Refraction at the Mid-Atlantic Ridge

从大西洋中脊底部折射得到的浅地壳层超镁铁质地震结构

• 批准号: 9819297
• 负责人: John Collins
• 金额: $ 17.21万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9819297&HistoricalAwards=false
• 关键词: Seismic; Structure; Ultramafics; Shallow; Crustal

A series of both on-bottom seismic refraction experiments using bottom shots and receivers, and seismic refraction profiles using airgun shots and seafloor receivers was conducted on the Mid-Atlantic Ridge in locations where there are extensive outcrops of mantle peridotites. The objectives of this project are to: (1) determine the depth extend of ultramafic bodies found in the three locations, (2) contrast the velocity structure at these known peridotite outcrops with that found in a typical extrusive-dike-gabbro igneous section formed at a fas spreading ridge, and (3) use the fine-scale velocity structure of these peridotite exposures to identify massive, unfractured outcrops where drilling conditions are good.

在中大西洋海脊广泛露出地幔橄榄岩的位置，进行了一系列使用底炮和接收器的海底地震折射实验，以及使用气枪和海底接收器的地震折射剖面。该项目的目标是：(1)确定在这三个地点发现的超镁铁矿体的深度范围；(2)将这些已知橄榄岩露头的速度结构与在Fas扩张山脊形成的典型喷发-岩脉-辉长岩火成岩剖面中发现的速度结构进行对比；(3)利用这些橄榄岩露头的精细速度结构来识别钻探条件良好的块状、未破裂的露头。