Impact of the Messinian Salinity Crisis in the Marmara Sea region. Did a connection exist between the Aegean and Black seas at that time?

Conference:

Turkish Geological Congress, 24-28 March, 2008, Ankara, Turkey.

Authors:

Georges Clauzon, Jean-Pierre Suc, Rolando Armijo, Bertrand Meyer, Mihaela Carmen Melinte-Dobrinescu, Gilles Lericolais, Hervé Gillet, M. Namik Çagatay, Speranta-Maria Popescu, Gwénnaël Jouannic, Gülsen Ucarkus, Ziyadin Çakir, Frédéric Quillévéré.

 

Abstract:

Several areas have been investigated in the region of the Sea of Marmara: Thrace (Gulf of Saros, Black Sea coastal area northwest Istanbul), Gelibolu Peninsula and Dardanelles (Çanakkale) Strait, Bithynia (southern edge of the Marmara Sea). This is a key-region because it is generally considered as the late Neogene passage zone between the Mediterranean and Black seas (Popov et al., 2006), and has beenseverely affected by the North Anatolian Fault (McKenzie, 1972; Şengör et al., 1985).

As Armijo et al. (1999) proposed that the MSC significantly impacted the region, we developed the following approach: (1) field (including seismic) investigations in order to identify the Messinian Erosional Surface (MES) and characterize which sediments overlie the MES, (2) micropaleontological analyses for precisely dating (foraminifers, nannoplankton mostly) deposits preceding and following the Messinian Salinity Crisis (MSC) and documenting the potential exchanges (dinoflagellates cycts) between the Aegean and Black seas.

The main results allow evidencing that:

  1. the subaerial (i.e. fluvial) erosion was relatively weak in the Gulf of Saros but intensive in the Black Sea shelf and slope west of Istanbul (Messinian canyon off Karacaköyreaching the Black Sea abyssal plain),
  2. the present-day Dardanelles Strait is superimposed on a Messinian canyon which appears to have been cut by the main channel of an important fluvial drainage network,
  3. the main Messinian drainage channels in the southern Marmara are located in the areas of Gönen and Bursa,

and supports that the gateway which connected the Mediterranean and Black seas in a two-way flow system just before and after the MSC was not located in the area (Popescu, 2006).