Lack of marine entry into Marmara and Black Sea-lakes indicate low relative sea level during MIS 3 in the northeastern Mediterranean

Abstract

Abstract. The Marine Isotope Stage 3 (MIS 3) is considered a period of persistent and rapid climate and sea level variabilities during which eustatic sea level is observed to have varied by tens of meters. Constraints on local sea level during this time are critical for further estimates of these variabilities. We here present constraints on relative sea level in the Marmara and Black Sea regions in the northeastern Mediterranean, inferred from reconstructions of the history of the connections and disconnections (partial or total) of these seas together with the global ocean. We use a set of independent data from seismic imaging and core-analyses to infer that the Marmara and Black Seas remained connected persistent freshwater lakes that outflowed to the global ocean during the majority of MIS 3. Marine water intrusion during the early MIS-3 stage may have occurred into the Marmara Sea-Lake but not the Black Sea-Lake. This suggests that the relative sea level was near the paleo-elevation of the Bosporus sill and possibly slightly above the Dardanelles paleo-elevation, ~80 mbsl. The Eustatic sea level may have been even lower, considering the isostatic effects of the Eurasian ice sheet would have locally uplifted the topography of the northeastern Mediterrranean.

Late Pleistocene-Holocene characteristics of the North Anatolian Fault at Adapazarı Basin: evidence from the age and geometry of the fluvial terrace staircases

“…The late MIS 3 high stand is a matter of debate, the global RSL was estimated as below the Bosporus-Dardanelles threshold (~90 m bsl) (Spratt and Lisiecki, 2016), but was also evidenced in coastal terraces in the Caucasian and Romanian shelf, reflecting that the sea level was 10-40 m bsl (Figure 9D, Panin, 1983;Chepalyga, 1984;Panin and Popescu, 2007) in the Black Sea. However, the d 18 O composition of the Sofular Cave records (Figure 9C, Badertscher et al, 2011) and paleosalinity interpretations from the Marmara and Black Sea cores (Yanchilina et al, 2019) rejected the idea of the intrusion of marine waters into the freshwater Black Sea at that time period. The most favored explanation for this phenomenon was a possible Caspian-Black Sea connection during the late MIS 3 (Yanina, 2014;Krijgsman et al, 2019), but this still needs to be verified by direct evidence and dating.…”