Joint 118th Annual Cordilleran/72nd Annual Rocky Mountain Section Meeting - 2022

Paper No. 42-3
Presentation Time: 2:20 PM


JIANG, Ganqing, Department of Geoscience, University of Nevada, Las Vegas, NV 89154-4010

The UNLV Geoscience Department has a tradition for field-based research and education in sedimentary geology. The Death Valley region and the southern Great Basin preserve an exceptional record of Neoproterozoic-Paleozoic strata that serve as the natural laboratory for sedimentary geology study. Faculty and students at UNLV conduct research projects focusing on a variety of topics including sedimentary basin evolution, petroleum source rocks and reservoirs, stratigraphy, sedimentology, paleoecology, and earth systems change across critical transitions in Earth history. One of the projects aims at elucidating the redox change across the major carbon isotope (δ13C) excursions. Theoretically, negative carbon isotope excursions involving remineralization of reduced carbon would result in expansion of oceanic anoxia, whereas positive δ13C excursions would lead to ocean oxygenation. However, examples from a few stratigraphic intervals including the Ediacaran-early Cambrian negative δ13C excursions and the Paleozoic positive δ13C excursions show the opposite or no change in geochemical proxy data. Understanding the cause of disparity in redox conditions across these major δ13C excursions requires detailed stratigraphic, sedimentological, and biostratigraphic studies to reconstruct the depositional environments and comparison of geochemical records within a reliable time framework. The well-exposed Paleozoic, carbonate-rich successions in the Great Basin provides a great opportunity for testing the various hypotheses.