SeaMARC II and Seismic Reflection Study of Strike-Slip Tectonics along the Northwestern Margin of the Caribbean Plate

SeaMARC II 和加勒比板块西北缘走滑构造的地震反射研究

• 批准号: 8812350
• 负责人: Alexander Shor
• 金额: $ 25万
• 依托单位: University of Hawaii
• 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: 1989-02-01 至 1990-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8812350&HistoricalAwards=false
• 关键词: SeaMARC; II; Seismic; Reflection; Study

Strike-slip faults are common geologic structures that separate geologic blocks. The North American-Caribbean strike-slip boundary provides a unique example of a large offset (-1100 km), active transform fault that exhibits characteristics of both oceanic and continental transforms. The plate tectonic controls on the structure of this interplate boundary in Central America and the western Cayman Trough remain poorly understood. Moreover, the relations between strike-slip faults of the interplate boundary and a broad zone of active interplate deformation - the Western Caribbean Extensional Province - have not been explored with modern marine geophysical techniques. The interpretation of this complex area has great implications for interpreting the structure of other active oceanic and continental strike-slip zones as well as ancient strike-slip faults now preserved in mountain belts. %%% This project involves a marine survey of structure in the Cayman Trough along the North American - Caribbean strike-slip boundary using the SeaMARC II high-resolution side-scan sonar. This survey is designed to help resolve several long-standing questions in strike-slip tectonics including how strike-slip faults and associated structures can be interpreted in terms of the direction of interplate motion and the stress state of the interplate area, and how the structure of strike-slip faults is affected by continental vs. oceanic crustal type.

走滑断层是分隔地质块体的常见地质构造。北美-加勒比走滑边界为大偏移（-1100 km）活动转换断层提供了一个独特的例子，显示了海洋和大陆转换的特征。板块构造对中美洲和开曼海槽西部板块间边界结构的控制作用尚不清楚。此外，现代海洋地球物理技术还没有研究过板块间走滑断层与板块间活动变形带——西加勒比伸展区之间的关系。这一复杂区域的解释对于解释其他海洋和大陆活动走滑带的结构以及现在保存在山带中的古走滑断层具有重要意义。该项目涉及使用SeaMARC II高分辨率侧扫声纳对沿北美-加勒比走滑边界开曼海槽结构进行海洋调查。这项调查旨在帮助解决走滑构造中几个长期存在的问题，包括如何根据板块间运动的方向和板块间区域的应力状态来解释走滑断层和相关结构，以及走滑断层的结构如何受到大陆与海洋地壳类型的影响。