Oceanic plateau of the Hawaiian mantle plume head subducted to the uppermost lower mantle
Oceanic plateau of the Hawaiian mantle plume head subducted to the uppermost lower mantle
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DOI：
10.1126/science.abd0312
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发表时间：
2020-11
期刊：
影响因子：
56.9
通讯作者：
S. Wei;P. Shearer;C. Lithgow‐Bertelloni;L. Stixrude;D. Tian
中科院分区：
文献类型：
--
作者：
S. Wei;P. Shearer;C. Lithgow‐Bertelloni;L. Stixrude;D. Tian
寻找帝王的头部 火山岛和海山链是由地幔深处涌出的热物质羽流形成的。其中最著名的是夏威夷-皇帝海山链。然而，与火山链之前的羽流头部相关的大型火山结构早已失踪。魏等人。最终确定了该结构在俄罗斯东部地幔中的可能位置。该结构可能在 2000 万至 3000 万年前被俯冲，并且该位置有助于限制多种地球动力学过程。科学，本期第 14 页。 983 2000 万至 3000 万年前，夏威夷-皇帝火山海山链的羽流头部俯冲到地幔中。包括夏威夷火山在内的夏威夷-皇帝海山链是由夏威夷地幔柱形成的。尽管地幔柱假说预测夏威夷热点起始阶段的大规模减压熔融会产生海洋高原，但该高原的命运尚不清楚。通过叠加SS前兆的地震波形，我们在鄂霍次克海以西的最上层下地幔中发现了兆米级的增厚洋壳部分。我们认为，这个厚厚的地壳代表了海洋高原的主要部分，它是由约 1 亿年前的夏威夷羽流头部形成的，并在 2000 万至 3000 万年前俯冲。我们的发现为未来的板块重建提供了夏威夷羽流早期历史的时空线索。
Finding the Emperor's head Volcanic island and seamount chains form from deep-seated plumes of hot material upwelling through the mantle. The most famous of these is the Hawaiian-Emperor seamount chain. However, a large volcanic structure associated with a plume head that should precede the chain has long been missing. Wei et al. finally identified the likely location of this structure in the mantle under eastern Russia. The structure was likely subducted 20 million to 30 million years ago, and the location helps constrain several geodynamic processes. Science, this issue p. 983 The plume head of the Hawaiian-Emperor volcano seamount chain was subducted into Earth’s mantle 20 million to 30 million years ago. The Hawaiian-Emperor seamount chain that includes the Hawaiian volcanoes was created by the Hawaiian mantle plume. Although the mantle plume hypothesis predicts an oceanic plateau produced by massive decompression melting during the initiation stage of the Hawaiian hot spot, the fate of this plateau is unclear. We discovered a megameter-scale portion of thickened oceanic crust in the uppermost lower mantle west of the Sea of Okhotsk by stacking seismic waveforms of SS precursors. We propose that this thick crust represents a major part of the oceanic plateau that was created by the Hawaiian plume head ~100 million years ago and subducted 20 million to 30 million years ago. Our discovery provides temporal and spatial clues of the early history of the Hawaiian plume for future plate reconstructions.