RUI: Arc-Continent Interaction and Evolution of the Caribbean-South American Plate Boundary

本项目涉及多道海洋地震研究 剖面，以解决结构和构造的历史， 小安的列斯群岛南部弧和邻近部分 南美洲大陆边缘。 研究的目的是 基于横向的边界识别 地震特征（振幅， 相干性，连续性）和反射体的速度， 识别结构并确定其时间， 基于与威尔斯井相关的分层序列。 最终 目标是解释现有的，新获得的数据，导致一个 提高对以下问题的认识：（1）弧-陆相互作用 导致大陆增生生长的过程， (2)东延构造历史 加勒比-南美洲边界区。 两个主要 关于板块边界的性质，已经提出了一些模型： (A)边缘平行，东走向走滑边界， 大，分布，右侧（东）位移的 小安的列斯群岛南部，和（B）一个斜碰撞区， 小安的列斯群岛南部的一次小的向东移动。 一 巨大的变形带，也许有几百公里宽， 这两个板块边界模型都是假设的。 因为这样 变形带大部分被淹没，海洋地震剖面 提供了除地震活动性和位场数据之外的唯一手段 来研究它在近海的结构 这项研究可能允许 上述两种模式之间的歧视或导致 开发一种新的替代模式。

This project involves study of multichannel marine seismic profiles to resolve the structural and tectonic history of the southern Lesser Antilles arc and adjacent parts of the continental margin of South America. Objectives of the study are the identification of terrane boundaries based on lateral discordance and change in seismic character (amplitude, coherency, continuity) and velocity of reflectors, and the identification of structures and determination of their timing in layered sequences based on correlation with wells. The ultimate goal is to interpret existing, newly obtained data, leading to an improved understanding of: (1) arc-continent interaction processes leading to the accretionary growth of continents, and (2) the structural and tectonic history of the eastern reach of the Caribbean-South American boundary zone. Two principal models have been proposed for the nature of the plate boundary: (A) a margin-parallel, east-striking strike-slip boundary with large, distributed, right-lateral (easterly) displacement of the southern Lesser Antilles, and (B) an oblique collision zone with small easterly displacement of the southern Lesser Antilles. A broad zone of deformation, perhaps hundereds of kilometers wide, is postulated by both of the plate boundary models. Because such a deformation zone is largely submerged, marine seismic profiles offer the only means besides seismicity and potential field data to study its structure in the offshore. The study may permit discrimination between the two aforementioned models or lead to the development of a new alternative model.