Age of the subducting Pacific slab beneath East Asia and its geodynamic implications
Age of the subducting Pacific slab beneath East Asia and its geodynamic implications
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DOI：
10.1016/j.epsl.2017.02.024
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发表时间：
2017-04-15
影响因子：
5.3
通讯作者：
Wei, Wei
中科院分区：
文献类型：
--
作者：
Liu, Xin;Zhao, Dapeng;Wei, Wei
本文利用高分辨率p波层析成像模型和古海底年龄资料研究了东亚俯冲太平洋板块的年龄。结果表明，从日本海沟（约130Ma）到中国东部板块西缘（约90Ma），俯冲板块的岩石圈年龄逐渐变年轻，地幔过渡带（MTZ）的平坦（停滞）板块是俯冲的太平洋板块，而不是伊扎那吉板块，后者应该已经塌陷到下地幔中。平坦的太平洋板块在MTZ存在的时间不超过1000万年至2000万年，远低于东亚大地幔楔的年龄（1000万年至1.1亿年）。因此，现今MTZ平坦的太平洋板块以广泛的板内火山活动和弧后扩张导致了东亚大陆岩石圈的新生代破坏，而早白垩世（类似于140-110Ma）华北克拉通的破坏是由伊扎那吉（或古太平洋）板块的俯冲引起的。(C) 2017 Elsevier B.V.版权所有
We study the age of the subducting Pacific slab beneath East Asia using a high-resolution model of P-wave tomography and paleo-age data of ancient seafloor. Our results show that the lithosphere age of the subducting slab becomes younger from the Japan Trench (similar to 130Ma) to the slab's western edge (similar to 90Ma) beneath East China, and the flat (stagnant) slab in the mantle transition zone (MTZ) is the subducted Pacific plate rather than the proposed Izanagi plate which should have already collapsed into the lower mantle. The flat Pacific slab has been in the MTZ for no more than similar to 10-20 million years, considerably less than the age of the big mantle wedge beneath East Asia (>110 million years). Hence, the present flat Pacific slab in the MTZ has contributed to the Cenozoic destruction of the East Asian continental lithosphere with extensive intraplate volcanism and back-arc spreading, whereas the destruction of the North China Craton during the Early Cretaceous (similar to 140-110Ma) was caused by the subduction of the Izanagi (or the Paleo-Pacific) plate. (C) 2017 Elsevier B.V. All rights reserved.