夏威夷-皇帝海山链成因机制——古地磁学约束

The kinematic mechanism study of Hawaii-Emperor seamount chain: Evidence from paleomagnetic records

夏威夷-皇帝海山链位于北太平洋中部,是一条自西北至东南延伸的海底火山链,并在47Ma存在一个方向弯折。厘定这一特征的成因机制和运动学过程,是西太平洋海区软流圈与岩石圈相互作用以及跨圈层物质能量交换的关键科学问题,对于解译东亚大陆动力学演化过程亦具有重要意义。目前对于夏威夷-皇帝海山链47Ma弯折的机制有两种争论:太平洋板块运动方向改变和热点移动。古地磁学是研究大陆漂移和板块演化的最有效手段之一,其最大优势是可以定量化研究地质历史时期中岩石圈板块的运动学过程。本文首先通过回顾与总结前人对夏威夷-皇帝海山链成因及转向机制的研究,重点探讨古地磁学在该问题上所提供的约束证据,并对存在的关键科学问题进行了梳理和展望。

The Hawaiian-Emperor seamount chain is located in the middle of North Pacific Ocean extending in a direction from northwest to southeast.It consists of two segments,the older Emperor China trending in N10°W and the Hawaiian chanin extending in N110°E.The research interests of the Hawaiian-Emperor seamount chain remain in the origin of seamount chain and the the sharp bend of the chain,which are the key to the investigation of the upwelling in the mantle,the movement of the lithosphere,and the exchange of material and energy between different layers.Paleomagnetism is the best tool for the kinematic studies on the seamount chain.In this paper,we summarized the previous studies on the formation mechanism of the Hawaiian-Emperor chain and the bend formed 47 Ma,with emphasis on the paleomagnetic evidence for the kinematics process of the Hawaiian-Emperor seamount chain.Key scientific topics and research directions were also discussed.