The Cretaceous History of the South Pacific Thermal and Isotopic Anomaly: The Magellan Seamounts

南太平洋热和同位素异常的白垩纪历史：麦哲伦海山

• 批准号: 9102183
• 负责人: Hubertus Staudigel
• 金额: $ 38.47万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 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: 1991-10-15 至 1995-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9102183&HistoricalAwards=false
• 关键词: Cretaceous; History; South; Pacific; Thermal

This Study will conduct a marine geophysical, geological, geochemical, and chronological investigation of 19 seamounts in the Magellan, Marshall, and Wake provinces in the western Pacific ocean. The goal is to document the Cretaceous Expression of the South Pacific Isotopic and Thermal Anomaly. Laser fusion 40Sr/39Ar dating will provide the age control on the samples. Radiogenic isotope geochemistry of mineral Separates of phenocrysts will be used to avoid seawater alteration effects. Gravity data will be inverted with respect to elastic thickness of the lithosphere and magnetic surveys will serve to determine the magnetic paleopoles. Thus this work will provide constraints on the Cretaceous extent of South Pacific Isotopic and Thermal Anamaly on Pacific plate motion prior to 100 Ma, constraints on the Cretaceous apparent polar wander path, and identification of potential hotspot chains.

本研究将对西太平洋麦哲伦、马歇尔和威克省的19座海底山进行海洋地球物理、地质、地球化学和年代学调查。目的是记录白垩纪南太平洋同位素和热异常的表达。激光聚变40Sr/39Ar定年将对样品进行年龄控制。斑晶矿物分离物的放射性成因同位素地球化学将用于避免海水蚀变效应。重力数据将根据岩石圈的弹性厚度进行反演，磁测量将用于确定磁性古磁极。因此，本研究将提供白垩纪南太平洋同位素范围的约束和100 Ma之前太平洋板块运动的热异常，白垩纪表观极移路径的约束，以及潜在热点链的识别。