Age, Origin, and Tectonic Significance of Mesozoic Rocks in the Magdalena-Margarita Region, SW Baja California Sur, Mexico

墨西哥南下加利福尼亚州西南部马格达莱纳-玛格丽塔地区中生代岩石的年龄、起源和构造意义

• 批准号: 9104771
• 负责人: Richard Sedlock
• 金额: $ 4.88万
• 依托单位: University of Missouri-Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 1992-07-01
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9104771&HistoricalAwards=false
• 关键词: Age; Origin; Tectonic; Significance; Mesozoic

The role of margin-parallel translations of accreted oceanic terranes is of current interest in transpressional orogens. This is an interdisciplinary investigation of deformed and metamorphosed oceanic rocks on islands off Baja California Sur, Mexico. The islands contain island arc assemblages, ophiolitic rocks, blueschist-facies subduction-related rocks and sparse cover, the ages of which are unknown but thought to be Mesozoic. This study will determine the ages of crystallization, coding, and metamorphism of the igneous rocks and will obtain geochemical, biostratigraphic, structural and paleomagnetic data. The results will be used to correlate tectonic terranes in western and southern Mexico and to determine the timing and magnitude of margin-parallel displacements. These findings will place important constraints on the tectonic evolution of the southern Cordillera of the western North American plate.

增生海洋地体边缘平行平移的作用目前在压折造山带中引起人们的兴趣。 这是对墨西哥南下加利福尼亚州附近岛屿变形和变质海洋岩石的跨学科研究。 这些岛屿包含岛弧组合、蛇绿岩、蓝片岩相俯冲相关岩石和稀疏的覆盖层，其年龄未知，但被认为是中生代。 这项研究将确定火成岩的结晶、编码和变质作用的年龄，并将获得地球化学、生物地层、结构和古地磁数据。 研究结果将用于关联墨西哥西部和南部的构造地体，并确定边缘平行位移的时间和幅度。 这些发现将对北美西部板块南科迪勒拉山脉的构造演化产生重要制约。