东印度洋Roo海隆区域属性及其俯冲区域响应特征

The Nature and the response characteristics of the Roo Rise to subduction zone in the eastern Indian Ocean

东南亚巽他弧形汇聚板块俯冲构造体系是全球最为活跃的板块汇聚边界地带之一,早期研究认为巽他弧俯冲体系主要发育俯冲增生型板块边缘,以典型的增生棱柱体弧前隆起地貌为主要特征;最新研究发现东印度洋沃顿海盆圣诞岛海底火山群省最东段Roo海隆已经随板块运动到达爪哇海沟区域,与巽他弧其他区域正常洋壳俯冲过程相比,Roo海隆凸起构造在巽他弧体系中触发了不同的俯冲地质过程.本文结合前人研究成果,全面梳理认识Roo海隆区域属性特征,包括海隆岩性与年代学特征、起源争议、“隆-沟”区域俯冲深部结构特征;进一步增强对弧前早期俯冲侵蚀过程的理解,包括局部增生棱柱体前缘碰撞侵蚀凹陷、弧前隆起差异性抬升、弧前盆地挤压破碎变窄;并首次利用二维多道地震资料解释,探讨弧后盆地对“隆-沟-弧-盆”新俯冲构造格局的响应特征.目前弧后肯登-马都拉海峡盆地内正在发生新一期挤压构造运动,我们认为其发育的浅层挤压背斜构造特征是Roo海隆凸起构造形成的垂直正交快速高角度新俯冲构造格局下弧后盆地内的直接构造变形响应.

The Sunda arc convergent plate subduction tectonic system in Southeast Asia is one of the most active convergent plate boundary zones in the world.Early studies suggest that the Sunda arc subduction system is mainly characterized by subducted accretionary plate margin and typical accretionary prism forearc uplift landform.The latest research found that the Roo Rise,the most eastern section of the Christmas Island Seamount Province in the Wharton Basin of the eastern Indian Ocean,has reached the Java Trench region with plate movement.Compared with the normal oceanic crust subduction process in other regions of the Sunda arc,the Roo Rise Uplift structure triggered different subduction geological processes in the Sunda arc system.In this paper,combined with previous research results,the nature of Roo Rise are comprehensively summarized and understood,including the lithology and chronological origin,and the deep subduction structure characteristics of the Rise-Trench area.To further enhance the understanding of the early forearc subduction erosion process,including local accretionary prism front edge collision concave,differential uplift of forearc uplift,the compression and narrowing of the forearc basin.We discuss the response characteristics of the backarc basin to the new subduction tectonic framework of“Rise-Trench-Arc-Basin”by using two-dimensional multichannel seismic data interpretation for the first time.At present,a new stage of compressional tectonic movement is taking place in the backarc Kendeng-Madura strait basin.We believe that the characteristics of the shallow compressional anticline are the direct tectonic deformation response in the backarc basin under the new vertical orthogonal fast and high angle subduction structure framework formed by the Roo Rise.