Petersen Kenni Dinesen, Schiffer Christian, Nagel Thorsten
Department of Geoscience, Aarhus University, 8000, Aarhus, Denmark.
Department of Earth Sciences, Durham University, Durham, DH1 3LE, UK.
Sci Rep. 2018 Nov 8;8(1):16578. doi: 10.1038/s41598-018-34194-0.
Large Igneous Provinces (LIPs) are commonly attributed to mantle plumes, hot upwellings from the deep lower mantle, apparently unrelated to plate motions. However, LIPs often form in association with rifting and breakup. Using numerical modelling, we introduce a novel idea that explains plume-like mantle upwelling by plate tectonic processes. Our model indicates that rifting-induced delamination of orogenic lithosphere can perturb the thermochemical mantle stratification and induce lower mantle upwelling which causes syn-rift LIP formation followed by protracted and enhanced mid ocean ridge basalt (MORB) generation. Our model provides an explanation for the geographical correlation between the Caledonian suture, the North Atlantic Igneous Province (NAIP) and present-day Icelandic magmatism.
大火成岩省（LIPs）通常被认为与地幔柱有关，即来自下地幔深部的热上升流，显然与板块运动无关。然而，大火成岩省常常与裂谷作用和大陆裂解相关联。通过数值模拟，我们提出了一个全新的观点，即通过板块构造过程来解释类似地幔柱的地幔上升流。我们的模型表明，造山岩石圈的裂谷作用诱发的拆沉作用能够扰乱热化学地幔分层，并引发下地幔上升流，进而导致同裂谷期大火成岩省的形成，随后是持续且增强的大洋中脊玄武岩（MORB）的生成。我们的模型为加里东缝合带、北大西洋火成岩省（NAIP）与现今冰岛岩浆活动之间的地理相关性提供了一种解释。
