Mantle Flow Patterns Beneath the Junction of Multiple Subduction Systems Between the Pacific and Tethys Domains, SE Asia: Constraints From SKS-Wave Splitting Measurements
Mantle Flow Patterns Beneath the Junction of Multiple Subduction Systems Between the Pacific and Tethys Domains, SE Asia: Constraints From SKS-Wave Splitting Measurements
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东南亚太平洋和特提斯域之间多个俯冲系统交界处的地幔流动模式：来自 SKS 波分裂测量的限制
DOI：
10.1029/2021gc009700
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Xuelin Qiu
中科院分区：
文献类型：
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作者：
Lingmin Cao;Xiaobo He;Liang Zhao;ChuanChuan Lü;Tianyao Hao;Minghui Zhao;Xuelin Qiu
东南亚西里伯斯海周边地区是在东有太平洋板块，南有印度-澳大利亚板块的辐合构造环境中演化的。它可以说是世界上构造最复杂的地区之一，是研究太平洋和特提斯构造域之间动态相互作用的理想场所。关于哪个俯冲板块在控制区域地幔流动中起主导作用的问题还没有得到很好的认识。地震各向异性观测可以表征地幔流动，为认识区域构造提供线索。我们利用位于西里伯斯海附近的7个地震台站的数据进行了dsks -波分裂分析。我们的研究结果与之前的观测结果相结合，表明该地区存在多种类型的地幔流，包括(a)西向俯冲的摩鹿加海（桑吉河）板块上方的地幔楔角流，(b)与东向俯冲的摩鹿加海（Halmahera）板块相关的两层各向异性，(c)由于靠近桑吉河板块边缘而导致的偏转流，(d)由于印度-澳大利亚板块的俯冲而导致的婆罗洲东南部下方的海沟-正常地幔流。(e)婆罗洲东北部的西北婆罗洲-巴拉望岛槽平行地幔流。不同类型的地幔流表明，自中生代冈瓦纳超大陆分裂以来，邻近俯冲带的动力相互作用对特提斯和西太平洋域之间的区域上地幔动力学起着至关重要的作用。
The region around the Celebes Sea, SE Asia, is evolving within a convergent tectonic environment involving the Pacific plate to the east and the Indian‐Australian plate to the south. It is arguably one of the most tectonically complex regions in the world and serves as an ideal setting to study dynamic interactions between the Pacific and Tethys tectonic domains. The issue of which subducting plate plays a leading role in governing the regional mantle flow is not well understood. Mantle flow can be characterized by seismic anisotropy observations, providing clues for understanding regional tectonics. We conductedSKS‐wave splitting analysis by using data from seven seismic stations located around the Celebes Sea. Our results, when combined with previous observations, suggest the presence of various types of mantle flow in this area, including (a) corner flow in the mantle wedge above the westward‐subducting Molucca Sea (Sangihe) slab, (b) two‐layer anisotropy related to the eastward‐subducting Molucca Sea (Halmahera) slab, (c) deflected flow due to proximity to the Sangihe slab's edges, (d) trench‐normal mantle flow beneath southeastern Borneo due to the subduction of the Indian‐Australian plate, and (e) Northwest Borneo‐Palawan trough‐parallel mantle flow beneath northeastern Borneo. Various types of mantle flow indicate that the dynamic interactions of adjacent subduction zones played crucial roles in influencing the regional upper mantle dynamics between the Tethys and western Pacific domains since the breakup of the Gondwana supercontinent in the Mesozoic.