Sedimentary records of basalt weathering in the Suol section of Siberia basin during the Permian-Triassic Transition

The Permian-Triassic transition was marked by severe climatic and environmental disturbances, culminating in the largest mass extinction event since the Phanerozoic era. Volcanic activity, particularly the eruptions associated with the Siberian Traps Large Igneous Province (STLIP), is widely regarded as the primary driver of this ecological crisis. However, it is still unclear about the ecosystem effects by the weathering of the basalt, although the volatile effects by volcanic releasing had been well explored. This study focuses on the Suol section in the Siberian Basin to explore the causal relationship between basalt weathering and climatic-environmental evolution during this critical period, by metal geochemistry, sedimentology, and mineralogical analyses.
Results show that the concentrations of nickel, copper, vanadium, scandium, cobalt, and other metals in sediments near the Permian-Triassic boundary align with the elemental composition of Siberian basalts, confirming that the primary source material originated from basaltic eruptions. Following the volcanic events, the weathering of exposed Siberian basalts continued to influence the metal cycling in the Suol section into the Early Triassic, which yielding higher temperature. Notably, mercury and carbon isotope records recovered swiftly to pre-eruption background levels during the Early Triassic, indicating that volatile components such as mercury and carbon had a short-term impact on the climate and environment. In contrast, the weathering of non-volatile components persisted, resulting in prolonged effects on the regional climate and ecosystem.
These findings highlight a temporal disparity in the release and impact of volatile versus non-volatile components during Siberian volcanic activity. Volatile emissions significantly influenced short-term climatic and environmental conditions, whereas basalt weathering under extremely higher temperature conditions exerted a long-term influence on geochemical cycles and ecosystem dynamics.