Figure 2
From: Anoxia/high temperature double whammy during the Permian-Triassic marine crisis and its aftermath
PTB mass extinction dead water model showing the only refuge zone for the crisis lay in a narrow refuge zone of intermediate water depths.
The chemocline separated anoxic and sulfidic deep waters from oxygenated surface waters and could move up and down during the Permian-Triassic interval14, causing the refuge zone to shift vertically following the chemocline. Bulk parameters in the water column are based on modern Black Sea15,16.
