Global impacts of evaporite deposition during the Messinian Salinity Crisis in transient Earth system model simulations

The Messinian Salinity Crisis (MSC, 5.9-5.3 Ma) is recognised as a period of dramatic regional environmental change but it is rarely considered in the interpretation of global environmental change in the late Miocene. Following Shields & Mills (2021), who showed that evaporite deposition has the potential to perturb the global carbon cycle, we investigate the temporal and spatial patterns of global environmental change resulting from the precession-paced extraction of the gypsum preserved until today in the Mediterranean basin in the 3D Earth system model cGENIE. The prescribed evaporite deposition causes a transient atmospheric CO2 draw-down of ~80 ppm and swings in the carbonate saturation state which causes sedimentary dissolution near the carbonate compensation depth, especially in the Pacific and Indian ocean. We compare the simulated model response to proxy records of late Miocene environmental change to test whether the fingerprint of the MCS evaporite deposition can be identified or whether additional buffer mechanisms need to be invoked to explain a more stable carbonate system.

 

References

Shields, G.A. and Mills, B.J., 2021. Evaporite weathering and deposition as a long-term climate forcing mechanism. Geology, 49(3), pp.299-303.