Fig. 3: Rhenium and molybdenum mass balance model results based on Gordondale Member authigenic metal enrichments to determine seafloor areas of anoxia (Aanoxic) and euxinia (Aeuxinic) prior to and during the Toarcian Oceanic Anoxic Event (T-OAE).
From: Global ocean redox changes before and during the Toarcian Oceanic Anoxic Event
All model results were determined using a bulk mass accumulation rate calculated from the median duration of the T-OAE (400 kyr)3,4,5. Pre-N-CIE model results (model intervals, MI-1 and MI-2) were determined with river inputs set to modern (4.29 × 105 mol Re yr−1; 3.00 × 108 mol Mo yr−1)18,19,33, while N-CIE intervals (MI-3 and MI-4) were determined with river input set to 3-times modern11. No results for the Mo mass balance modeling are presented for MI-2 or MI-3 because the minimal enrichments indicate local redox conditions (non-euxinic anoxic or suboxidizing) that do not reflect changes to the global dissolved seawater Mo reservoir. Mean values are shown as solid black lines, bracketed by 1 standard deviation shaded boxes. Abbreviations: m, meters; PCS, Poker Chip Shale; N-CIE, negative carbon isotope excursion.
