Oscillating Quaternary water levels of the Marmara Sea and vigorous outflow into the Aegean Sea from the Marmara Sea Black Sea drainage corridor

Aksu A., Hiscott R., YAŞAR D.

MARINE GEOLOGY, vol.153, pp.275-302, 1999 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 153
  • Publication Date: 1999
  • Doi Number: 10.1016/s0025-3227(98)00078-4
  • Journal Name: MARINE GEOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.275-302
  • Dokuz Eylül University Affiliated: No


Detailed interpretation of single-channel air-gun and deep-tow boomer profiles demonstrates that the Marmara Sea, Turkey, experienced small-amplitude (similar to 70 m) fluctuations in sea level during the later Quaternary, limited in magnitude by the sill depth of the Strait of Dardanelles. Moderate subsidence along the southern shelf and Quaternary glacio-eustatic sea-level variations created several stacked deltaic successions, separated by major shelf-crossing unconformities, which developed during the transitions from global glacial to integlacial periods. Near the Strait of Dardanelles, a series of sand-prone deposits are identified beneath an uppermost (Holocene) transparent mud drape. The sandy deposits thicken into mounds with the morphology and cross-sectional geometries of barrier islands, sand waves, and current-generated marine bars. All cross-stratification indicates unidirectional flow towards the Dardanelles prior to the deposition of the transparent drape which began similar to 7000 years BP, in strong support: of the notion that the Marmara Sea flowed westwards into the Aegean Sea through the Dardanelles at times of deglaciation in northern Europe. The global sea-level curve shows that, at similar to 11,000 and similar to 9500 years BP, sea level rose to the sill depths of the Straits of Dardanelles and Bosphorus, respectively. The effect from similar to 11,000 to similar to 9500 years BP was seawater incursion into the Marmara Sea, drowning and formation of algal-serpulid bioherms atop lowstand barrier islands, and transgression of shelves and lowstand deltas. At similar to 9500 years BP, glacial meltwater temporarily stored in the Black Sea lake, developed into a vigorous southward flow toward the Aegean Sea, forming west-directed sandy bedforms in the western Marmara Sea and initiating deposition of sapropel S1 in the Aegean Sea. This strong outflow persisted until similar to 7000 years BP, after which a mud drape began to accumulate in the Marmara Sea and euryhaline Mediterranean mollusks successfully migrated into a progressively more saline Black Sea where sapropel deposition began. Most eastern Mediterranean sapropels from S1 to S11 appear to correlate with periods of rising sea level and breaching, or near-breaching, of the Bosphorus sill. These events are believed to coincide with times of vigorous outflow of low-salinity (?fresh) surface waters transiting the Black Sea-Marmara Sea corridor, and ultimately derived from melting of northern European ice sheets. (C) 1999 Elsevier Science B.V. All rights reserved.