Tectonic Evolution of St. Croix

圣克罗伊岛的构造演化

• 批准号: 9017408
• 负责人: Robert Speed
• 金额: $ 9.5万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-03-01 至 1993-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9017408&HistoricalAwards=false
• 关键词: Tectonic; Evolution; St.; Croix

This study will address the tectonic evolution of St. Croix during Cretaceous and Cenozoic times in order to obtain constraints on the tectonic evolution of the northeastern Caribbean region and the Caribbean - American plate boundary zone. Cretaceous sedi- mentary rocks on St. Croix will be analyzed to determine their age range, environments of deposition, determine their age range, provenance, ages of metamorphism, and the geometry and kinematic development of the tectonic complex they occupy. Syntectonic igneous dikes, sills, and plutons will also be studied to determine their age range and relationship to the developing tectonic complex. The geometry and kinematics of the Cenozoic graben on St. Croix will be examined and its relation to regional extension in the NE Caribbean ascertained. St. Croix differs from nearby islands in that it is the only subaerial exposure of bedrock between the Puerto Rico - Virgin Islands platform and the Venezuelan Basin. Resolution of the tectonic history of St. Croix as a result of this study will form an essential component in our understanding of the tectonic evolution of the NE Caribbean. The results will also have important implications for understanding the tectonics of major plate/micro plate interactions.

这项研究将研究圣克罗伊岛在白垩纪和新生代的构造演化，以获得对加勒比海东北部地区和加勒比-美洲板块边界带构造演化的制约。将对圣克罗伊岛白垩纪沉积岩进行分析，以确定它们的年龄范围、沉积环境、年龄范围、物源、变质年龄以及它们所处的构造杂岩的几何学和运动学发展。还将研究同构造火成岩岩脉、岩床和深成岩浆，以确定它们的年龄范围及其与发展中的构造杂岩的关系。将研究圣克罗伊岛新生代地块的几何学和运动学，并确定其与东北加勒比海区域伸展的关系。圣克罗伊岛与附近岛屿的不同之处在于，它是波多黎各-维尔京群岛平台和委内瑞拉盆地之间唯一的海底露出的基岩。这项研究的结果是解决圣克罗伊的构造历史，这将成为我们理解东北加勒比构造演化的重要组成部分。这一结果也将对理解主要的板/微板相互作用的构造具有重要的意义。