Fig. 6
From: Mesophilic microorganisms build terrestrial mats analogous to Precambrian microbial jungles
Global elemental budgets and fluxes. Land coverage is based on a total land surface area of 2.5 × 107 km2 (ref. 50). At about 0.02% land coverage, the measured gross oxygen production could account for the present sulphate flux and would exceed historic values. At a coverage of about 1%, it would match modern oxidative weathering and volcanism, or modern organic carbon burial. A coverage of more than 100% is required to reach the estimated Archean gross marine primary productivity. Shaded areas for sulphate flux, methane flux, and gross primary productivity refer to fluxes ranging from Archean (darker colours) to present (lighter colours) values. Horizontal lines represent global production, diagonal lines represent terrestrial production dependent on land coverage (modified after44). Values according to ref. 44 were recalculated for 2% of land surface to be covered by rivers and lakes52
