STRUCTURAL EVOLUTION-OIL POTENTIAL RELATIONSHIPS IN THE MARMARA SEA,NW TURKEY

In spite of gas production in the K. Marmara gasfield , many non explored zones, which could contain important prospects, could still exist in the Marmara Sea.Evaluations of seismic lines,well and field data indicate that Osmancik sandstones , eroded and transported from the northern Istranca Massif's metamorphics, constitute prospective sandstone channels and incised valleys in the Kumburgaz area, while prospective reefoidal Sogucak limestones and likely Hamitabat sandstones are localized in the northern and middle part of the Marmara Sea. Occurrence of prospective structures started their evolution since Late Cretaceous with emplacement of ophiolites which provided paleohigh and basement for overlying younger Eocene and Oligocene reservoir units. During the Miocene time, appearence of the North Anatolian Fault (NAF) generated multiple splays which compartmented existing formations and ameliorated also reservoir characteristics wity formation of fractures and small scale faults. Evaluations of data inticate that some regions in the Marmara Sea remain still unexplored to date. Future oil and gas discoveries in these zones will contribute a lot to the Turkish economy.