Astronomically Paced Marine Biological Evolution During the Late Paleozoic Icehouse-To-Greenhouse Transition

Home , Biogeology, Late Paleozoic icehouse

EGU21-13809, updated on 28 Sep 2021 https://doi.org/10.5194/egusphere-egu21-13809 EGU General Assembly 2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License.

Astronomically paced marine biological evolution during the Late Paleozoic icehouse-to-greenhouse transition

Qiang Fang1,2, Huaichun Wu1,2, Shuzhong Shen3,4, Junxuan Fan3,4, Linda Hinnov5, Shihong Zhang1, and Tianshui Yang1 1State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China 2School of Ocean Sciences, China University of Geosciences, Beijing 100083, China 3State Key Laboratory for Mineral Deposits Research and School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China 4Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing 210023, China 5Department of Atmospheric, Oceanic, and Earth Sciences, George Mason University, Fairfax, Virginia 22030, USA

Late Paleozoic deglaciation is the Earth’s first icehouse-to-greenhouse transition in a vegetated world, but the climatic and biological responses to this transition have not yet been fully addressed. We conducted cyclostratigraphic analysis on the magnetic susceptibility from a deep marine carbonate succession in South China, to reconstruct the astrochronology of the late Early Permian, and to decipher evolutionary responses to astronomically forced climate changes in a marine diversity time series. Our results indicates that the minima of ~1.8 m.y. short orbital eccentricity amplitude modulation cycles led to seasonally stable precipitation patterns and a constant input of nutrients, which spurred marine biodiversity during this deglaciation. Synchronizing global biotic and abiotic records reveals that peaks of marine biodiversity occurred during nodes of ~1.3 m.y. obliquity amplitude modulation cycles, when ice sheet expansion triggered enhanced precipitation and organic carbon burial during icehouse conditions (290−285.1 Ma). Starting at 285.1 Ma, the insolation-biodiversity relationship began to change, paced by glacial termination and tropical aridification. With the transition to greenhouse conditions (~279.1−272 Ma), obliquity nodes became associated instead with terrestrial aridity and marine anoxia, and suppression of marine speciation. Our results bring into focus a pattern of shifting dynamics involving Earth’s astronomical parameters, climate change and marine biodiversity for icehouse and greenhouse worlds in the late Paleozoic Era.