See more from this Division: Topical Sessions
See more from this Session: Paleozoic Oceanographic and Climatic Changes: Evidence from Seawater Geochemistry and Sedimentology Records II
Abstract:
Changes in distribution of lithofacies, significant surfaces, and their stacking into meter to 10s of meter-scale cycles recorded in carbonate-dominated (Arrow Canyon, NV) to mixed carbonate-siliciclastic successions (Appalachian and Donets basins) record the onset of short-term (104-yr) relative sea-level fluctuations during the upper Visean (basal-most Chesterian) and delineate significant variation in amplitudes (<10 to >50 m) of inferred glacioeustasty through to the Early Permian. Synchronous cyclostratigraphic and sedimentologic changes document a late Moscovian-Kasimovian glacial minimum characterized by decreased effective moisture and increased seasonality, as well as two short-lived, early Pennsylvanian glacial minima. The enigmatic occurrence of glendonites in lower Moscovian (Atokan) Arrow Canyon cyclic strata, which record high-amplitude sea-level fluctuations, indicate near-freezing shallow tropical waters during peak glaciation. Proposed glacial minimum are coincident with ice-free conditions in Antarctica and Eastern Australia, widespread aridification, and significant floral and faunal turnover, whereas peak glacial periods are associated with increased humidity, dampened seasonality and present-day CO2 levels suggesting a strong link between tropical environmental change and high-latitude glaciation.
See more from this Division: Topical Sessions
See more from this Session: Paleozoic Oceanographic and Climatic Changes: Evidence from Seawater Geochemistry and Sedimentology Records II