The astronomical control on sedimentary cyclicity, generally resulting in alternation of organic-rich shales deposited during more humid periods and marls during arid phases, has been already demonstrated for many Mediterranean Neogene sequences. However, this strict relation has never been proved for the Messinian salinity crisis. The role of climate on the deposition of evaporites was, so far, inferred from the assumption that gypsum can only form during arid phases but other independent climate proxies (e.g. calcareous microfossils) are missing. BIOCLIMA reconstructed for the first time the high frequency (20 myr) climatic fluctuations during the Messinian salinity crisis using geochemical proxies like major and trace elements and molecular fossils derived from terrestrial plants. Surprisingly, this study revealed that no major climate change occurred at the onset of the Messinian salinity crisis.
BIOCLIMA has identified the predominant climate (humidity vs aridity) and environmental (salinity, oxygenation, temperature and fertilization of seawater) parameters, which characterized the advent of the MSC and dramatically influenced biological communities. An estimate of the temperature of the Messinian seawater has been also suggested on the basis of the commonly used TEX86 paleothermometer
Climate-controlled sedimentary cyclicity in the Pollenzo section (Piedmont, Italy)