Australian Antarctic Southern Ocean Profiling Project

Metadata record for data from ASAC Project 1119See the link below for public details on this project.A marked bend in the Hawaiian-Emperor seamount chain supposedly resulted from a recent major reorganization of the plate-mantle system there 50 million years ago. Although alternative mantle-driven and plate-shifting hypotheses have been proposed, no contemporaneous circum-Pacific plate events have been identified. We report reconstructions for Australia and Antarctica that reveal a major plate reorganization between 50 and 53 million years ago. Revised Pacific Ocean sea-floor reconstructions suggest that subduction of the Pacific-Izanagi spreading ridge and subsequent Marianas/Tonga-Kermadec subduction initiation may have been the ultimate causes of these events. Thus, these plate reconstructions solve long-standing continental fit problems and improve constraints on the motion between East and West Antarctica and global plate circuit closure.

本数据集为ASAC项目1119的元数据记录，点击下方链接可查看该项目的公开详情。夏威夷-帝王海山链存在一处显著拐点，被认为是该区域于5000万年前发生的一次重大板块-地幔系统重组所导致的结果。尽管已有学者提出地幔驱动与板块漂移两类替代假说，但目前尚未发现与此同期的环太平洋板块活动事件。本研究针对澳大利亚与南极洲开展板块重建，结果揭示了5000万至5300万年前发生的一次重大板块重组事件。经修正的太平洋洋底板块重建模型显示，太平洋-伊邪那岐扩张脊的俯冲作用，以及后续马里亚纳/汤加-克马德克俯冲带的起始活动，可能是上述事件的根本诱因。综上，本研究的板块重建模型解决了长期存在的大陆拼合难题，并优化了东南极与西南极之间的运动约束，以及全球板块回路闭合的相关限定。