Tectonic Framework of Turkish Sedimentary Basins

Pinar Oya Yilmaz

Turkey's exploration potential primarily exists in seven onshore (Southeast Turkey platform, Tauride platform, Pontide platform, East Anatolian platform, Interior, Trace, and Adana) basins and four offshore (Black Sea, Marmara Sea, Aegean Sea, and Mediterranean Sea) regional basins formed during the Mesozoic and Tertiary.

The Mesozoic basins are the onshore basins: Southeast Turkey, Tauride, Pontide, East Anatolian, and Interior basins. Due to their common tectonic heritage, the Southeast Turkey and Tauride basins have similar source rocks, structural growth, trap size, and structural styles. The central and eastern parts of the Tauride basin differ in terms of reservoir, seal, and structural growth. These differences result from different structural timing. The Southeast Turkey and western Tauride basins grew during the post-middle Miocene and the central and east Tauride structures grew during the Eocene. The Southeast Turkey basin is one of the producing basins in Turkey.

In the north, another Mesozoic basin, the Pontide platform, has a much more complex history and very little in common with the southerly basins. The Pontide has two distinct parts; the west has Paleozoic continental basement and the east is underlain by island-arc basement of Jurassic age. The plays are in the upper Mesozoic rocks in the west Pontide.

The remaining Mesozoic basins of the onshore Interior and East Anatolian basins are poorly known and very complex. Their source, reservoir, and seal are not clearly defined. The basins formed during several orogenic phases in Mesozoic and Tertiary.

The Cenozoic basins are the onshore Thrace and Adana basins, and all offshore regional basins formed during Miocene extension. Further complicating the onshore basins evolution is the superposition of Cenozoic basins and Mesozoic basins. The Thrace basin in the northwest and Adana basin in the south both originate from Tertiary extension over Tethyan basement and result in a similar source, reservoir, and seal. Local strike-slip movement along the North Anatolian fault modifies the Thrace basin structures, influencing its hydrocarbon potential.

The offshore basins all have a common origin associated with Miocene extension. They contain clastic and carbonate source, reservoir, and seal rocks. They differ markedly, however, in size and play type. All offshore basins are formed by pure extension with the exception of Iskenderun Bay basin, which has been modified later by strike-slip faulting.

AAPG Search and Discovery Article #91032©1988 Mediterranean Basins Conference and Exhibition, Nice, France, 25-28 September 1988.