Walker-Trivett C A, Kender S, Bogus K A, Littler K, Edvardsen T, Leng M J, Lacey J, Riding J B, Millar I L, Wagner D
Camborne School of Mines, Department of Earth and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, TR10 9FE, UK.
British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK.
Nat Commun. 2024 Jun 15;15(1):5124. doi: 10.1038/s41467-024-49032-3.
Large Igneous Provinces (LIPs) are associated with global warming and carbon cycle perturbations during Oceanic Anoxic Event 2 (OAE2, ~94 Ma) and the Mid-Cenomanian Event (MCE, ~96.5 Ma). However, there is still no consensus on the role volcanism played as a trigger, or its source - previously ascribed to the Caribbean LIP or High Arctic LIP. Here, we use Mentelle 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, indicates Kerguelen LIP volcanic activity and plateau uplift occurred in the lead up to and within OAE2. Whilst we find limited evidence that a volcanic event caused the MCE, pulsed Hg spikes before and during OAE2 imply volcanic emissions were key in driving climate and carbon cycle changes and triggering OAE2.
大火成岩省（LIPs）与海洋缺氧事件2（OAE2，约9400万年前）和森诺曼阶中期事件（MCE，约9650万年前）期间的全球变暖及碳循环扰动有关。然而，关于火山活动作为触发因素所起的作用，或者其来源——此前归因于加勒比大火成岩省或高北极大火成岩省，仍未达成共识。在此，我们利用门泰勒盆地沉积物中的汞（Hg）浓度来确定火山活动的时间，并利用钕（Nd）和锶（Sr）同位素来确定沉积物来源。与北半球记录相比，高汞浓度以及向放射性钕同位素的转变表明，凯尔盖朗大火成岩省的火山活动和高原隆升发生在OAE2之前及期间。虽然我们发现火山事件导致MCE的证据有限，但OAE2之前和期间汞的脉冲式峰值表明，火山排放是推动气候和碳循环变化以及触发OAE2的关键因素。
