Hydroclimate Change Enhanced Landscape Erosion During the Early Permian Deglacial Warming

Abstract

The early Permian (Artinskian) deglacial warming represents a significant climate transition with notable ecosystem reorganization within the late Paleozoic icehouse, yet its impact on tropical landscape erosion remains unclear. In this study, we analyze the siliciclastic Liangshan Formation in western South China deposited during this interval using sandstone petrology, mudrock geochemistry, detrital mineral ages, zircon α‐dose values, and paleogeography as constraints. All lines of evidence, including zircon grains with rounded inherited overgrowths, Zr enrichment, consistently high weathering intensity, major detrital zircon and rutile U‐Pb age populations of 700−500 Ma and 1100−900 Ma, and systematically lower zircon α‐dose relative to the putative sources, indicate a recycled provenance from the pre‐Permian Paleozoic sedimentary rocks. DZmix modeling suggests source contributions of ca. 49%, 20% and 29% from the Devonian, Silurian and Cambrian‐Ordovician siliciclastic successions in western South China, respectively. These provenance data reveal enhanced physical erosion by deep incision, especially from the Devonian quartzose sandstones, and suggest a sedimentary regime distinctly different from that recorded by the preceding carbonate‐dominated successions. Coupling climate model results with stream power law, we attribute this enhanced erosion in South China to increased mean‐annual precipitation and associated expansion of fluvial system leading to effective removal of sediments from source to sink. In contrast, coeval rapid erosion in equatorial Pangea is best explained by greater discharge variability and more frequent threshold‐exceeding floods under arid conditions. Results of this study provide a comprehensive framework for interpreting sediment flux variations during past global warming events.