Paratethys pacing of the Messinian Salinity Crisis: Low salinity waters contributing to gypsum precipitation?

Abstract

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Preliminary results based on geochemical sedimentary constraints on the hydrocarbon potential and depositional environment of a Messinian sub-salt mixed siliciclastic-carbonate succession onshore Crete (Plouti section, eastern Mediterranean)

“…Although type III kerogen can be associated with aquatic organic matter in marine settings (Tissot et al 1974), its prevalence in the studied sediments can be also related to transportation by fluvial processes (Vandenbroucke and Largeau 2007). Late Miocene runoff into the eastern Mediterranean basin was at least three times greater than that of today (Gladstone et al 2007), based on the cumulative effect of the African rivers in the south and the Paratethys freshwater supply in the north (Krijgsman et al 2010;Moissette et al 2010;Natalicchio et al 2014;Karakitsios et al 2013Karakitsios et al , 2017aVan Baak et al 2017;Vasiliev et al 2019;Grothe et al 2020). Therefore, the presence of type III kerogen could at least partly be associated with terrestrial inputs associated with the above two fluvial systems building out into the marine depositional environment.…”

The response of water column and sedimentary environments to the advent of the Messinian salinity crisis: insights from an onshore deep-water section (Govone, NW Italy)

“…The integration of geochemical, sedimentological and petrographic data indicates that during the early phase of the MSC the water column in the Piedmont Basin was stratified and comprised (1) an oxygenated upper layer, typified by mostly marine conditions and receiving input of freshwater from rivers (Natalicchio et al 2019;Sabino et al 2020) and/or low-salinity water from the Paratethys (Grothe et al 2020); and (2) an anoxic to euxinic lower layer, formed by denser, more saline waters (Dela Natalicchio et al 2017), the latter agreeing with The two water masses were separated by a pycnocline, at which chemical gradients established with time and a chemocline developed, as observed for modern basins (Wakeham et al 2007(Wakeham et al , 2012 and reconstructed for ancient basins with stratified water masses (e.g. the Badenian basin of Eastern Europe; Babel, 2004;Babel & Bogucki, 2007).…”

“…In contrast, only a few geochemical data are available for the sediments deposited during the early stages of the MSC (Kenig et al 1995;Sinninghe Damsté et al 1995b;Isaji et al 2019a). These studies all describe organic-rich shales of the PLG unit, depicting a stratified basin that received freshwater from rivers (Natalicchio et al 2017(Natalicchio et al , 2019Sabino et al 2020) and/or low-salinity water from the Paratethys (Grothe et al 2020).…”

From the Eastern Paratethys to the Pontocaspian basins

“…Despite faunal and palaeogeographic preconditions, the acquired Sr isotope-ratios from our record strongly contradicts any significant open interbasinal connections. Comparison of values with those from the Eastern Paratethys (Grothe et al, 2020) and the Mediterranean (Roveri et al, 2014b) shows that the Denizli values are much lower and most likely represent a local water source (Fig. 2.12).…”

“…This event, known as Pontian flooding or Pontian Salinity Incursion is observed in all Eastern Paratethyan affinities (Dacian, Euxinian and Caspian Basins) (Krijgsman et al, 2010;Stoica et al, 2013;Grothe, 2016;van Baak et al, 2016;. Strontium isotope ratios and organic geochemistry data suggest a Mediterranean origin for this incursion (Vasiliev et al, 2015;Grothe et al, 2020). Immediately after the Pontian salinity incursion, the Eastern Paratethys was invaded by new Pontian faunal assemblages (mollusc, dinoflagellates, ostracods) originating from Lake Pannon (Central Paratethys) (Magyar et al, 1999;Grothe et al, 2018).…”