Testing the core-mantle boundary & large igneous province hypothesis: a full-vector palaemagnetic study of the North Atlantic Igneous Province

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Background: Large Igneous Provinces (LIPs) are large areas of volcanism that erupt over millions of years causing rapid environmental change and mass extinctions, e.g., the PermianTriassic mass extinction. It has been suggested that LIPs are delayed expressions of energy release from the Earth's Core; hot plumes from the Core-Mantle Boundary (CMB) rise over a period of ~50 Myr to form hotspots. When a hotspot first breaks through the Earth's crust aLIP forms. Before the energy release at the CMB, it is very likely that the Earth's Core was hotter than usual. It is predicted that increases in temperature, will increase fluid-flow rates in the outer Core, increasing the efficiency of the geodynamo, leading to higher geomagnetic field intensities than usual (Biggin, et al., 2012). However, these ideas have not been rigorously tested. The Columbia River Basalts, north west USA, is a 'small' LIP that occurred~17-14 Ma and is associated with the Yellowstone hotspot, and the North Atlantic Igneous Province (NAIP) is a LIP that erupted ~64 to 54 Ma centred on the Icelandic hotspot. The NAIP was broken up during the formation of the Atlantic Ocean and now extends from eastern Greenland, the Faroe Islands, Northern Ireland and Scotland. If the hypothesis of Biggin et al. (2012) is correct, then there should be a low in the intensity recorded by the NAIP LIP basaltsdue to the initial formation of the plume that forms the Yellowstone hotspot. However, modern ancient absolute geomagnetic field intensity estimates recovered from NAIP rocks are very limited. There are older estimates, especially from Scotland, however, these no longer meet modern quality criteria.Project: There are two main aims of the project: 1) Test the CMB & LIP hypothesis of Bigginet al. (2012), by collecting samples from both the Faroe Isles and the western coast of theBritish Isles; 2) Determine extrusion rates of the NAIP, and to help understand its potential linkto the Paleocene-Eocene Thermal Maximum and climate change (Jones et al., 2019).