Fig. 6
The effect of the parameter, J, on GEOCARBSULFOR oxygen outputs, compared to another method of calculating atmospheric oxygen. The black line is our baseline model run with J = 4. The grey dashed line is J = 5, the grey dotted line is J = 2.5, and the grey dot-dash line is J = 7.5 for our GEOCARBSULFOR model. The blue line is J = 5, the dashed line is J = 7.5 and the dotted line is J = 2.5 from Edwards et al.55. The red line shows the approximate maximum atmospheric O2 (10.4% atm) for the Cambrian and earlier, based on geochemical water column redox data and allowing for modelling uncertainties14,72,73. The orange line is the approximate O2 minimum, based on the same redox data, as well as Cambrian biota and wildfire oxygen requirements2,4,14
