SeaMARC II and Seismic Reflection Study of the Southeast Bahamas-Hispaniola Collision Zone

SeaMARC II 和巴哈马东南部-伊斯帕尼奥拉碰撞带的地震反射研究

• 批准号: 8812351
• 负责人: Alexander Shor
• 金额: $ 18.98万
• 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: 1989-01-15 至 1990-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8812351&HistoricalAwards=false
• 关键词: SeaMARC; II; Seismic; Reflection; Study

Accreted shallow-water carbonate terranes are a common feature of many ancient mountain belts, yet the tectonic history of the majority these terranes remains poorly understood. In many cases, this is because early deformational structures associated with initial accretion have been overprinted and obliterated by post-accretion structural and metamorphic events. In order to fully understand the mechanism(s) of these shallow- water carbonate terranes, an active collision zone involving a shallow-water carbonate bank must be studied. A detailed swath mapping and seismic reflection study of the active collision between the southeastern Bahamas and the island of Hispaniola will be used. Here, the small, isolated banks of the Bahamas are colliding obliquely with the northern margin of Hispaniola, as part of the broad, transpressional North American-Caribbean Plate boundary. The collisional setting of the southeast Bahamas contrasts markedly with the tectonically quiescent, passive-margin setting of the northwest Bahamas, providing an unparalleled opportunity to compare and contrast the development of shallow-water carbonate banks in widely differing tectonic regimes. proposed use of the SeaMARC II seafloor mapping system, in conjunction with digitally recorded single-channel seismic reflection profiles, provides a system that is ideally suited for our proposed studies, which will focus on documenting shallow structures and surficial sedimentary features within the collision zone. %%% Carbonate deposits in mountain belts are commonly associated with shallow marine sediments that have been thrust onto the continent during tectonic episodes. This project will study carbonate sediments on the Hispaniola margin as a modern analog of the type of carbonate terrains that are found in tectonically active regions. The sedimentology and structural setting will be examined using a combination of coring, seismic stratigraphy, and side-scan sonar imaging (SeaMarc II). Results may be used to interpret carbonate sediments in the many accreted terrains where such deposits are found.

增生的浅水碳酸盐地体是许多古代山带的共同特征，但大多数这些地体的构造历史仍然知之甚少。在许多情况下，这是因为与初始吸积相关的早期变形结构已被吸积后结构和变质事件所覆盖和消除。 为了充分了解这些浅水碳酸盐岩地体的机制，必须研究涉及浅水碳酸盐岩滩的活动碰撞带。 将使用巴哈马东南部和伊斯帕尼奥拉岛之间主动碰撞的详细测绘和地震反射研究。 在这里，巴哈马群岛的小而孤立的河岸与伊斯帕尼奥拉岛的北缘倾斜碰撞，作为广阔的压裂北美-加勒比板块边界的一部分。 巴哈马东南部的碰撞环境与巴哈马西北部的构造静止、被动边缘环境形成鲜明对比，为比较和对比不同构造体系中浅水碳酸盐岩滩的发育提供了无与伦比的机会。 拟议使用 SeaMARC II 海底测绘系统，结合数字记录的单道地震反射剖面，提供了一个非常适合我们拟议研究的系统，该系统将重点记录碰撞带内的浅层结构和地表沉积特征。 %%% 山地带中的碳酸盐沉积物通常与构造时期推挤到大陆上的浅海沉积物有关。 该项目将研究伊斯帕尼奥拉岛边缘的碳酸盐沉积物，作为构造活跃地区碳酸盐地形类型的现代模拟。 将结合取芯、地震地层学和侧扫声纳成像 (SeaMarc II) 来检查沉积学和构造环境。 结果可用于解释发现碳酸盐沉积物的许多增生地形中的碳酸盐沉积物。