Climate conditions of coals and evaporates in the Earth history

Coals and evaporates are the most commonly used paleoclimate indicators, regarded as representatives of humid and arid climate conditions in the geological record, respectively. However, the quantitative and systematic climate significance of coals and evaporates in the Earth history still unknown. Here, we perform a series of simulations to simulate global climate conditions of Phanerozoic, using an Earth system model CESM 1.2.2 and reconstructed paleotopographies (Scotese, 2018). Combining with a global-scale complication of coals and evaporate from the present back to Devonian (Boucot et al., 2013), climate variables of annual average surface temperature (AAST), annual average precipitation (AAP) and annual average net precipitation (AANP) of the area where coals and evaporates formed are extracted for analysing quantitative climate conditions of coals and evaporates. The preliminary results show that (1) AAST of evaporate areas vary with global mean temperature, while the variation of coals areas’ AAST reflect a stage change,which are consistent with the stage evolution of land plant and lignin-degrading fungi; (2) AAP and AANP of coals and evaporates areas are relatively stable through the Earth history. Coals areas have general more AAP and AANP than evaporates in 25%-75% quantiles but have similar range with evaporites areas in 5%-95% quantiles.

 

Key words: coals, evaporates, plant evolution, deep-time climate, numerical simulation

References

Scotese C R, 2018. PALEOMAP PaleoAtlas Rasters[J].

Boucot A J, Chen X, Scotese C R, 2013. Lithology Data Tables[J].