On the relationship between volcanic hotspot locations, the reconstructed eruption sites of large igneous provinces and deep mantle seismic structure
On the relationship between volcanic hotspot locations, the reconstructed eruption sites of large igneous provinces and deep mantle seismic structure
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DOI：
10.1016/j.epsl.2014.11.052
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发表时间：
2015-02-01
影响因子：
5.3
通讯作者：
Sambridge, M.
中科院分区：
文献类型：
--
作者：
Davies, D. R.;Goes, S.;Sambridge, M.
有人提出，火山热点和重建的大火成岩省（LIPS）的喷发地点优先位于两个深地幔大的低剪切波速度省（LLSVP）的边缘以上，在非洲大陆和太平洋。这种空间相关性已被解释为意味着LLSVP代表长寿，致密，稳定的热化学堆，优先触发地幔柱在其边缘，并施加强烈的影响下地幔动力学。在这里，我们重新分析这种空间相关性，证明它不是全球性的：它是强大的非洲LLSVP，但太平洋弱。此外，基于蒙特卡罗的统计分析表明，观察到的非洲和太平洋热点/重建的LIPS的分布与假设一致，即它们是从均匀分布在每个LLSVP的整个面积范围内的样本中提取的：与非洲LLSVP边缘的更强的空间相关性预计是其拉长的几何形状的简单结果，其中超过75%的LLSVP内部位于其边缘的100以内。我们的研究结果意味着，热点和重建的LIPs的地理分布并不表明化学异质性影响下地幔动力学的程度。(C)2014爱思唯尔有限公司版权所有。
It has been proposed that volcanic hotspots and the reconstructed eruption sites of large igneous provinces (LIPS) are preferentially located above the margins of two deep mantle large low shear-wave velocity provinces (LLSVPs), beneath the African continent and the Pacific Ocean. This spatial correlation has been interpreted to imply that LLSVPs represent long-lived, dense, stable thermo-chemical piles, which preferentially trigger mantle plumes at their edges and exert a strong influence on lower-mantle dynamics. Here, we re-analyse this spatial correlation, demonstrating that it is not global: it is strong for the African LLSVP, but weak for the Pacific. Moreover, Monte Carlo based statistical analyses indicate that the observed distribution of African and Pacific hotspots/reconstructed LIPS is consistent with the hypothesis that they are drawn from a sample that is uniformly distributed across the entire areal extent of each LLSVP: the stronger spatial correlation with the margin of the African LLSVP is expected as a simple consequence of its elongated geometry, where more than 75% of the LLSVP interior lies within 100 of its margin. Our results imply that the geographical distribution of hotspots and reconstructed LIPs does not indicate the extent to which chemical heterogeneity influences lower-mantle dynamics. (C) 2014 Elsevier B.V. All rights reserved.