Park, Y., Swanson-Hysell, N. L., Macdonald, F. A., Lisiecki, L. E., 2020, Evaluating the relationship between large igneous province area and Earth’s long-term climate state: AGU Geophysical Monograph Series 255 – Large Igneous Provinces: A Driver of Global Environmental and Biotic Changes, preprint doi:10.31223/osf.io/p9ndf.
Macdonald, F. A., Swanson-Hysell, N. L., Park, Y., Lisiecki, L. E., Jagoutz, O., 2019, Arc-continent collisions in the tropics set Earth’s climate state: Science, vol. 364, pp. 181–184, doi:10.1126/science.aav5300.
On multimillion-year time scales, Earth has experienced warm ice-free and cold glacial climates, but it is unknown whether transitions between these background climate states were the result of changes in carbon dioxide sources or sinks. Low-latitude arc-continent collisions are hypothesized to drive cooling by exhuming and eroding mafic and ultramafic rocks in the warm, wet tropics, thereby increasing Earth’s potential to sequester carbon through chemical weathering. Similarly, the chemical weathering of large igneous provinces (LIPs) are also hypothesized to drive cooling, although importantly LIPs tend to erupt onto stable continental interiors or into subsiding sedimentary basins during rifting, and are therefore not actively exhumed.
To better constrain global weatherability through time, the paleogeographic positions of all major Phanerozoic arc-continent collisions (Fig. 1) and LIPs (Fig. 2) were reconstructed and compared to the latitudinal distribution of ice sheets. This analysis reveals a strong correlation between the extent of glaciation and arc-continent collisions in the tropics (Fig. 3). These results suggest that Earth’s climate state is set primarily by global weatherability, which changes with the latitudinal distribution of arc-continent collisions. On the other hand, we find no significant correlation between LIP area in the tropics and the extent of continental ice sheets (Fig. 4). These results suggest that changes in planetary weatherability associated with LIPs are not the fundamental control on whether Earth is in a glacial or nonglacial climate, although they could provide a secondary modulating effect in conjunction with other processes.