Bonadio Raffaele, Lebedev Sergei, Chew David, Xu Yihe, Fullea Javier, Meier Thomas
Department of Earth Sciences, Bullard Laboratories, University of Cambridge, Cambridge, UK.
School of Cosmic Physics, Dublin Institute for Advanced Studies, Dublin, Ireland.
Nat Commun. 2025 Aug 22;16(1):7837. doi: 10.1038/s41467-025-62967-5.
Mantle plumes, the hot upwellings from the Earth's core-mantle boundary, are thought to trigger surface uplift and the emplacement of large igneous provinces (LIPs). Magmatic centres of many LIPs are scattered over thousands of kilometres. This has been attributed to lateral flow of plume material into thin-lithosphere areas, but evidence for such flow is scarce. Here, we use abundant seismic data and recently developed methods of seismic thermography to map previously unknown plate-thickness variations in the Britain-Ireland part of the North Atlantic Igneous Province, linked to the Iceland Plume. The locations of the ~ 60 Myr old uplift and magmatism are systematically where the lithosphere is anomalously thin at present. The dramatic correlation indicates that the hot Iceland Plume material reached this region and eroded its lithosphere, with the thin lithosphere, hot asthenosphere and its decompression melting causing the uplift and magmatism. We demonstrate, further, that the unevenly distributed current intraplate seismicity in Britain and Ireland is also localised in the thin-lithosphere areas and along lithosphere-thickness contrasts. The deep-mantle plume has created not only a pattern of thin-lithosphere areas and scattered magmatic centres but, also, lasting mechanical heterogeneity of the lithosphere that controls long-term distributions of deformation, earthquakes and seismic hazard.
地幔柱是从地球核幔边界涌起的热物质流，被认为会引发地表隆升和大火成岩省（LIPs）的形成。许多大火成岩省的岩浆中心散布在数千公里的范围内。这被归因于地幔柱物质向岩石圈较薄区域的侧向流动，但这种流动的证据很少。在这里，我们利用丰富的地震数据和最近开发的地震热成像方法，绘制了北大西洋火成岩省英国-爱尔兰部分与冰岛地幔柱相关的、此前未知的板块厚度变化图。约6000万年前隆升和岩浆活动的位置系统地分布在目前岩石圈异常薄的地方。这种显著的相关性表明，炽热的冰岛地幔柱物质到达了该区域并侵蚀了其岩石圈，岩石圈变薄、软流圈炽热及其减压熔融导致了隆升和岩浆活动。我们进一步证明，英国和爱尔兰目前板内地震活动分布不均也集中在岩石圈较薄的区域以及沿岩石圈厚度变化的地方。深部地幔柱不仅造就了岩石圈较薄区域和分散岩浆中心的格局，还造成了岩石圈持久的力学非均质性，这种非均质性控制着变形、地震和地震灾害的长期分布。
