Phys.org June 17, 2024
Anoxic events are prolonged periods where large expanses of the Earth’s oceans are depleted of dissolved oxygen, which creates toxic waters and leads to mass extinction and habitat loss. The cause of this anoxic event which lasted >500,000 years has been a source of debate among experts. Researchers in the UK used basin sedimentary mercury (Hg) concentrations to determine the timing of volcanism, and neodymium (Nd) and strontium (Sr) isotopes for sedimentary provenance. High Hg concentrations compared to Northern Hemisphere records, and a shift to radiogenic Nd isotopes, indicated Kerguelen LIP volcanic activity and plateau uplift occurred in the lead up to and within OAE2 (Oceanic Anoxic Event 2). While they found limited evidence that a volcanic event caused the MCE (Mid-Cenomanian Event), pulsed Hg spikes before and during OAE2 implied volcanic emissions were key in driving climate and carbon cycle changes and triggering OAE2… read more. Open Access TECHNICAL ARTICLE
Mid-Cretaceous paleogeography and large igneous provinces.
Credit: Nature Communications volume 15, Article number: 5124 (2024)Â