An archaeal biomarker record of paleoenvironmental change across the onset of the Messinian salinity crisis in the absence of evaporites (Piedmont Basin, Italy)

摘要

Highlights?Archaea flourish and diversify at the onset of the Messinian salinity crisis.?Molecular fossils of halophiles appear at this time but evaporites are absent.?Coeval occurrence of planktonic Thaumarchaeota and halophilic Euryarchaeota.?Water column stratification occurs after the onset of the Messinian salinity crisis.AbstractA sudden change from normal marine to extreme paleoenvironmental conditions occurred approximately 6Ma ago in the Mediterranean Basin at the onset of the late Miocene Messinian salinity crisis, one of the most severe ecological crises in Earth history. Strong evaporation and tectonics led to hypersaline conditions, resulting in widespread deposition of evaporites and the apparent annihilation of the marine metazoan biosphere. In contrast to the prominent occurrence of evaporites elsewhere in the Mediterranean, evaporites did not form in the deeper part of some marginal basins at the