SEDIMENTATION on THE ARABIAN SHELF HAS BEEN UNDER THE CONTROL OF TECTONIC ACTIVITIES ALONG THE ZAGROS–TAURIDE THRUST BELT FROM THE CRETACEOUS TO THE PRESENT

Turkey is located on seismically active Alpine-Himalayan Orogenic Belt. The recent tectonics of Anatolia is resulted from the plate-wise developed tectonic deformation. The Bitlis-Zagros thrust belt formed as the southern branch of the Neotethyan Ocean closed as a result of the N-S and NE-SW convergence and collision between the Arabian-African and Eurasian plates. Structures of the neotectonic period in the region are the products of intra-plate tectonic processes that occurred after this collision. Throughout Anatolia a peneplain morphology became dominant with the beginning of this neotectonic era related to the crustal shortening developed under the compressional tectonic regime. The Southeast Anatolian Thrust, which is located along the southern front of the Bitlis Suture Zone, is one of the mega-tectonic structures that has shaped the neotectonic structure of Anatolia together with the North and East Anatolian Faults.

Tectonic events: Southeast Anatolia which forms the northern margin of the Arabian plate has experienced three significant compressional phases during the paleotectonic period between the Early Cretaceous and Middle Miocene. These compressional regimes prevailed during: 1^st Late Cretaceous, 2^nd-Early Eocene, probably Late Paleocene, and 3^rd Post-Middle Eocene, probably during the Late Eocene. On the other hand, the neotectonic period, mainly a contractional regime, which marks the 4^th event, began during the Middle Miocene and continues in Present time.

The first paleotectonic period was experienced during the Late Cretaceous and was resulted in thrusting of the allochthonous units including the oceanic material of the northerly-located Tethyan Ocean. The allochthonous units emplaced onto the Arabian plate in this period filled the Campanian basin located along the northern margin of the continent. After filling of the Campanian basin with allochthonous units, transgression from south to north begins on the Arabian plate during the Maastrichtian and a significant part of the outcrop area of the allochthonous units was covered by continental (pebblestone-sandstone-mudstone) and marine (limestone-marl-sandstone) units as part of the transgressive series.

By the end of the Paleocene, a new tectonic period, which affected the northeastern margin of the Arabian continent, caused folding, uplifting and erosion in the north and east of Southeast Anatolia. After this folding and erosion stage, with an early Eocene transgression, a significant part of Southeast Anatolia fell under the marine environment conditions again.

During the early-middle Eocene, transgression reached to its maximum boundaries in Southeast Anatolia and the region was totally inundated. In this period, in the northerly-located fault controlled basin whose basement consisted of the Bitlis Metamorphic units and the Guleman Group the Maden Complex was formed. By the end of the Eocene, the northern margin of the Arabian continent was strongly affected by N-S compression, the Maden Basin was closed, and the Maden Complex together with the underlying metamorphic and ophiolitic rocks in large nappe systems were thrust towards to the south. These tectonic events have shown their effects on the Arabian Continent and during the late Eocene, a regional regression began on the Southeast Anatolian platform. On the late Eocene-Oligocene facies maps of southeast Anatolia signs of this tectonic event and the consequent regression can be seen clearly.

The late Miocene is the period in which tectonism was the most effective in Southeast Anatolia. In this period, the amplitude of the thrust faults formed in the region was larger than those formed previously. The N-S stress regime in the Miocene resulted in E-W striking structural axes in the region.

The compressional forces affecting Southeast Anatolia in the late Miocene caused first the formation of low-angle thrusts and then strike slip faults. Except for the East Anatolian Fault, which extends sub-parallel to the suture zone, other faults affected directly the autochthonous platform of the Arabian Continent. These faults are related to intra-plate deformation and differ from the East Anatolian Fault Zone. Each tectonic event created its own structural style and petroleum trap system.