Table 1 Model results for both the carbon cycle (primary production, carbon burial, carbon remineralization, and methane production) and the iron cycle (iron recycling and iron deposition) at 2.5 Ga.

Low, Middle, and High represent the model outputs from the low, middle, and high parts of the ranges depicted by the gray boxes in Fig. 5 and fig. S8. For reference, modern rates of primary production (PP) range from 2760 to 3510 Tmol C year−1 (60).

C
PP
C burialC remineralizationC to Fe reductionC to CH4
production
Fe
recycling
Fe
deposition
(upwelling
province)
Global Fe
deposition
Global CH4
Tmol
C/year
% of PP% of PP% of
remineralization
% of
remineralization
Tmol
Fe/year
Tmol
Fe/year
Tmol
Fe/year
Tmol
CH4/year
2.5 Ga Low4.514.885.272.627.411.11.017.90.5
2.5 Ga Middle14.814.785.349.150.924.89.959.13.2
2.5 Ga High22.514.685.441.059.031.417.589.95.7