“Missing links” for the long-lived Macdonald and Arago hotspots, South Pacific Ocean

The goal of this study is to characterize a suite of lavas from an atoll and several seamounts located between Samoa and the Cook Islands. These are volcanic features thought to result from the passage of the Pacific plate over two different hotspots, Macdonald hotspot and Arago-Rurutu hotspot. Ages from the atoll (Rose atoll) are consistent with an origin over the Arago-Rurutu hotspot, while ages from one of the seamounts (Moki seamount) are consistent with an origin over the Macdonald hotspot. The other seamounts do not have material appropriate for age-dating, but they have radiogenic isotopic signatures consistent with an origin over either the Arago-Rurutu or Moki seamounts.

本研究旨在表征位于萨摩亚与库克群岛之间的一组熔岩及若干海山。这些火山地貌被认为是太平洋板块经过两个不同热点（麦克唐纳热点与阿拉戈-鲁鲁图热点）上方形成的。该环礁（罗斯环礁）的年龄与阿拉戈-鲁鲁图热点起源的特征一致，而其中一座海山（莫基海山）的年龄则与麦克唐纳热点起源的特征相符。其他海山缺乏适合年代测定的物质，但它们的放射性同位素特征与源自阿拉戈-鲁鲁图热点或莫基海山所在热点的特征一致。