Exploring the Impact of Cenomanian Paleogeography and Marine Gateways on Oceanic Oxygen

The Cenomanian-Turonian period recorded one of the largest disruptions to oxygen and carbon cycles, Oceanic Anoxic Event 2 (OAE2, 94 Ma). This event is global, yet paleo-reconstructions document heterogeneous ocean oxygenation states sedimentary contents, temporally spatially, suggesting that several mechanisms are at play. To better understand long-term controls on oceanic initial conditions prevailing beginning OAE2, we perform numerical simulations Cenomanian using IPSCL-CM5A2 Earth System Model, which includes a marine biogeochemistry component. We examine control biogeochemical global Central Atlantic oceans by depth American Seaway (CAS). show vigorous circulation existed during before OAE2 dysoxia/anoxia was caused paleogeography rather than stagnation. existence restricted basins, disconnected from deep supplied with oxygen-depleted waters Oxygen Minimum Zones surrounding played key role in development dysoxic/anoxic regions. A comparison redox-proxy data suggests connection between Pacific prior OAE2. shallowing CAS may have contributed establishment enhanced anoxia Atlantic, but cannot be only triggering factor. paleogeographic configuration gateways appear as major factors controlling distribution, leading extended low-oxygenated areas prerequisite necessary for occur.