A post Younger Dryas Black Sea regression identified from sequence stratigraphy correlated to core analysis and dating

Abstract

The north-western Black Sea shelf is the widest continental shelf of the Black Sea, where the Danube delta/prodelta system includes important records on the Black Sea water level fluctuations. This study integrates newly acquired high-resolution single channel seismic reflection profiles and Calypso piston cores recovered along a transect extending from the Danube delta deep into its deep sea fan. The correlated results provide information on the Late Quaternary architecture of the Danube Black Sea shelf and on the role of global glacio-eustatic fluctuations on the building of the Danube delta/prodelta. The sedimentary sequences in the Black Sea are strongly affected by water level changes. For the whole duration of Late Glacial-Holocene period, the level of the Black Sea was controlled by the regional climate modifications rather than the global eustatic changes. The seismic sequences recognized on a very high-resolution seismic profile were dated by two Calypso piston cores. Based on the obtained data, during the Last Glacial Maximum the Black Sea was a land locked lake with the level below -120 m. In the course of the deglaciation the lake level rose up to -40 m, which is confirmed by occurrence of the prodelta lobes formed after the rise in water level originated from the melt water. Following the Younger Dryas, 11 000-8500 (14)C BP, there occurred a new level lowering to the level of -100 m, identified by the forced regression deposits recorded on the Romanian shelf. This last lowstand previously recognized by a pronounced shoreline with a characteristic beach profile and a belt of coastal dunes is also indicated by the prodelta at 100 m depth. All these coastal features as well as the incised anastomosed channel system remained preserved on the shelf resulting from a rapid ultimate transgression starting immediately after 8500 (14)C BP

Anatomy of a compound delta from the post-glacial transgressive record in the Adriatic Sea

“…This is possible in contexts where the rates of sea level rise and sediment supply overwhelm the sediment dispersion rates of the currents (Davis and Clifton, 1987). This interpretation is in agreement with the "cliff overstep" model proposed by Zecchin et al (2011) for steep shelves where relative high sea level rise connected to the Meltwater pulses promotes a rapid drowning of cliff portions with related rapid excursion of the shoreline; and with the documentations of the high sediment supply recorded on the Mediterranean shelves during the Younger Dryas interval (e.g., Labaune et al, 2005;Berné et al, 2007;Lericolais et al, 2010;Maselli et al, 2011;Sømme et al, 2011). The further jump in sea level highlighted by the subsequent landward migration of the uTST unit depocenter (Fig.…”

“…The lower and upper TST units (lTST and uTST unit, respectively) record an abrupt landward shift of the shoreline, while the middle unit (mTST unit) is prograding seaward and represents a regressive sedimentary body within the TST (Cattaneo and Trincardi, 1999). The three TST units are separated by two prominent, and extensively erosional, surfaces (S1 and S2 surface, Cattaneo and Trincardi, 1999; Jouet et al, 2006;Sømme et al, 2011;Chiocci et al, 1991;Lykousis et al, 2005;Aksu et al, 2002;Giosan et al, 2009;Lericolais et al, 2010;Schattner et al, 2010;Zecchin et al, 2011;Durán et al, 2013) and highstand clinothemes (green patches; Díaz and Ercilla, 1993;Lobo et al, 2006;Fanget et al, 2014;Cattaneo et al, 2007;Hiscott et al, 2002;Giosan et al, 2013). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)…”

Evolution of the Danube Deep-Sea Fan since the Last Glacial Maximum: new insights into Black Sea water-level fluctuations

“…At that time, the water level was controlled by regional climate and varied independently from global sea level (Ross et al, 1970). Based on seismic stratigraphy (Ryan et al, 1997;Winguth et al, 2000;Aksu et al, 2002;Lericolais et al, 2009Lericolais et al, , 2010Lericolais et al, , 2011 and reservoir age reconstructions (Soulet et al, 2011a), it is suggested that the water level of the Black Sea 'Lake' oscillated from ca − 150/− 100 m (e.g., during the LGM) to ca. − 35/− 25 m, that corresponds to the depth of the Bosphorus sill.…”

Absolute chronology of fluvial events in the Upper Dnieper River system and its palaeogeographic implications

“…Therefore it makes unlikely the Black Sea to have kept low stage in the Early Holocene. Even if this lowstand had been really occurring, it could hardly be governed by river runoff decrease as it was proposed in (Lericolais et al, 2010).…”

“…According to Lericolais et al (2010), in the period 13.0-9.5 ka cal BP (11.0-8.5 ka 14 C BP) the Black Sea exhibited regression and low stand, which was followed by rapid ultimate transgression starting immediately after ~9.5 ka cal BP (8.5 ka 14 C BP). According to our results, the Upper Dnieper River had high discharges since the very beginning of the Holocene till about 8 ka cal BP.…”