Upper- and mid-mantle interaction between the Samoan plume and the Tonga-Kermadec slabs.
Upper- and mid-mantle interaction between the Samoan plume and the Tonga-Kermadec slabs.
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DOI：
10.1038/ncomms10799
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发表时间：
2016-02-29
影响因子：
16.6
通讯作者：
Faccenda M
中科院分区：
文献类型：
--
作者：
Chang SJ;Ferreira AM;Faccenda M
地幔柱被认为在将热量从核幔边界传递到岩石圈方面起着关键作用，在那里它可以显着影响板块构造。地幔柱在扩张脊或板内环境中撞击岩石圈时，可能产生热点、大的火成岩省，从而产生相当大的动态地形。然而，地幔柱对俯冲板块的积极作用仍然知之甚少。在这里，我们表明，在660公里的停滞和最快的沟槽撤退的汤加板块在西南太平洋是一致的相互作用与萨摩亚羽流和Hikurangi高原。我们的研究结果是基于3D各向异性层析成像图像和3D岩石热力学模型之间的比较，这些模型自洽地解释了斐济-汤加地区的几个独特特征。我们确定了四个可能的滑动系统的bridgmanite在下地幔，调和汤加板（VSH>VSV）下观察到的地震各向异性与热机械计算。 烟羽-板层相互作用及其表面表达仍然知之甚少。在这里，作者比较了3-D各向异性层析成像和地球动力学模型，并表明汤加板块的停滞和最快的沟槽撤退与萨摩亚羽流和Hikurangi高原的相互作用是一致的。
Mantle plumes are thought to play a key role in transferring heat from the core–mantle boundary to the lithosphere, where it can significantly influence plate tectonics. On impinging on the lithosphere at spreading ridges or in intra-plate settings, mantle plumes may generate hotspots, large igneous provinces and hence considerable dynamic topography. However, the active role of mantle plumes on subducting slabs remains poorly understood. Here we show that the stagnation at 660 km and fastest trench retreat of the Tonga slab in Southwestern Pacific are consistent with an interaction with the Samoan plume and the Hikurangi plateau. Our findings are based on comparisons between 3D anisotropic tomography images and 3D petrological-thermo-mechanical models, which self-consistently explain several unique features of the Fiji–Tonga region. We identify four possible slip systems of bridgmanite in the lower mantle that reconcile the observed seismic anisotropy beneath the Tonga slab (VSH>VSV) with thermo-mechanical calculations. Plume-slab interaction and its surface expression remain poorly understood. Here, the authors compare 3-D anisotropic tomography and geodynamical models, and show that the stagnation and fastest trench retreat of the Tonga slab are consistent with an interaction with the Samoan plume and the Hikurangi plateau.