Influence of the Timing of Accommodation Space on the Sedimentary Record of the Earth’s Climate

Mrofka, David D.¹, Martin Kennedy² (1) University of California, Riverside, Riverside, CA (2) University of California Riverside, Riverside, CA

Over 30 years ago, Crowell began investigating the timing and synchronicity of Neoproterozoic glaciations on Rodinian margins to understand the influence, interplay and implications of tectonism and climate on the sedimentary record. This question is more topical than ever with the implications of global catastrophic glaciation for the Earth System. A popular conception of the Neoproterozoic record is that the presence of discrete glacial intervals within a succession records an equal number of discrete global climate events. This assumes synchronicity of glacially influenced sedimentation in a time period with generally poor time constraints. An alternative links regional tectonism with diachronous glaciation, connecting uplift and adiabatic climate forcing. Data from the Kingston Peak Formation (KPF) of Death Valley, California demonstrate another alternative, pulses in tectonically derived accommodation space preserving a biased record of apparently discrete glacial events. Distinctive marker beds extending 100 km between the Panamint Mountains and the Kingston Range connect two distinct regions of KPF. In the Panamints, coarse-grained rift-associated facies interpreted as glacial are not expressed in the Kingston Range. Rifting appears to propagate southeastwards toward the Kingston Range producing accommodation space filled variably by intervals of rift and glacially influenced facies. The cessation of synsedimentary faulting in both areas leads to the termination of a glacial record that we relate to loss of accommodation space, not glacial termination. While the KPF has been interpreted as a record of discrete climate events, we interpret it as recording a single climate event with discrete intervals of accommodation driven preservation.