Pacific Plate Motion 30-70 Ma: Seamount Geochronology in the Western Pacific and the Origin of the Hawaii-Emperor Bend

太平洋板块运动30-70 Ma：西太平洋海山年代学和夏威夷-皇帝湾的起源

• 批准号: 9730394
• 负责人: Hubertus Staudigel
• 金额: $ 48.8万
• 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: 1998
• 资助国家: 美国
• 起止时间: 1998-11-01 至 2004-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9730394&HistoricalAwards=false
• 关键词: Pacific; Plate; Motion; 30; 70

SUMMARYOceanic hot spots leave trails of volcanoes that can be interpreted in terms of tectonic plate motion. The motion of the Pacific Plate is most prominently reflected in the Hawaiian/Emperor seamount chain with a characteristic bend at about 42 Ma. The timing of this change based on dating of rocks is almost 10 million years younger than the age calculated from marine magnetic anomalies, and it has been suggested that the Hawaiian hot spot may have moved with respect to other hot spots. The Gilbert Ridge and the Tokelau seamount chain display a similar bend at their southern terminations, and offer an opportunity to improve our accuracy of absolute Pacific Plate motion and to test for the validity of the fixed hot spot concept. This project will dredge rocks from these seamount chains and date samples by 40 Ar/39 Ar isotopic methods.

海洋热点留下的火山痕迹可以用构造板块运动来解释。 太平洋板块的运动最突出地反映在夏威夷/皇帝海山链上，该海山链在大约42 Ma时具有特征性的弯曲。 根据岩石测年，这一变化的时间比海洋磁性异常计算的年龄年轻近1000万年，有人认为夏威夷热点可能相对于其他热点移动了。 吉尔伯特海脊和托克劳海山链在其南端也显示出类似的弯曲，这为我们提供了一个机会，以提高我们对太平洋板块绝对运动的准确性，并检验固定热点概念的有效性。 该项目将从这些海山链中挖掘岩石，并用40 Ar/39 Ar同位素方法测定样品的年代。