ORIGINAL Late glacial to Holocene sea-level changes in the Sea of Marmara: new evidence from high-resolution seismics and core studies Kürşad Kadir Eriş & M. N. Çağatay & Sena Akçer & Luca Gasperini & Yosi Mart Received: 11 December 2009 / Accepted: 28 April 2010 / Published online: 12 May 2010 # Springer-Verlag 2010 Abstract The late glacial to Holocene sedimentary record of the northern shelf of the Sea of Marmara (SoM) has been documented by detailed seismo-, chrono-, and biostratigraphic analyses using sub-bottom (Chirp) profiles and sediment cores. During MIS 3 and the main part of MIS 2 (60–15 14 C ka B.P.), disconnection from the Mediterranean and Black seas together with a dry climate resulted in a regression in the SoM, when the Sea was transformed into a brackish lake. The river incisions below 105 m water depth along the northern shelf took place during the last glacial maximum, when the lake level was modulated by stillstands at -98 and -93 m. The post- glacial freshwater transgressive stage of the Marmara ‘Lake’ occurred between 15 and 13.5 14 C ka B.P., leading to a rise in water level to -85 m by 13.0 14 C ka B.P., as evidenced by broad wave-cut terraces along the northern shelf. Since 12 14 C ka B.P., high-frequency sea-level fluctua- tions have been identified at the SoM entrance to the Strait of İstanbul (SoI). Thus, wave-cut terraces have been recorded at water depths of -76 and -71 m that, according to an age model for core MD04-2750, have ages of 11.5 and 10.5 14 C ka B.P., respectively. Ancient shoreline at -65 m along the northern shelf presumably formed soon after the Younger Dryas (YD) at ca. 10.1 14 C ka B.P. Moreover, there is compelling evidence of Holocene outflow from the Sea of Marmara to the Black Sea. At the SoM entrance to the SoI, the existence of bioherms on the reflector surface together with abundant Brizalina spathulata and Protoglobulimina pupoides in a core suggests a return to higher salinities due to strong Mediterranean water incursion into the SoM at ∼8.8 14 C ka B.P. This finding is consistent with earlier suggestions that, after the YD, the Black Sea was flooded by outflow from the SoM as a result of global sea-level rise. Introduction The Sea of Marmara (SoM) is connected to the Black Sea and the Aegean Sea through the straits of İstanbul (SoI; -35 m) and Çanakkale (Dardanelles; -70 m), respectively (Fig. 1a). Compared to the southern shelf, the northern shelf is relatively narrow (<20 km), with a shelf break at -90 m. Seeing that the SoM forms the oceanographic gateway between the Black and Aegean seas, the chronology of paleoclimatic and paleoceanographic events associated with the late glacial–interglacial transition is crucial for the understanding of the sea-level history in this region. Although considerable work has been carried out on paleoceanographic aspects of the SoM (e.g., Lane-Serff et al. 1997; Çağatay et al. 1999, 2000, 2003, 2009; Algan et al. 2001; Görür et al. 2001; Aksu et al. 2002a, b; Hiscott et al. 2002; Mudie et al. 2002; Sperling et al. 2003), little has been reported on sea-level changes during the time period extending from the last glacial maximum (LGM) to the Holocene (e.g., Eriş et al. 2007; McHugh et al. 2008; Çağatay et al. 2009; Gökaşan et al. 2010; Vidal et al. 2010). Electronic supplementary material The online version of this article (doi:10.1007/s00367-010-0211-1) contains supplementary material, which is available to authorized users. K. K. Eriş (*) : M. N. Çağatay : S. Akçer Geology Department, Istanbul Technical University, Istanbul 34469, Turkey e-mail: keris@itu.edu.tr L. Gasperini ISMAR-CNR Bologna, Institute of Marine Geology, Bologna 40129, Italy Y. Mart Recanati Institute for Marine Studies, University of Haifa, Haifa 31905, Israel Geo-Mar Lett (2011) 31:1–18 DOI 10.1007/s00367-010-0211-1