Hazro Yükselimi’nin (Kuzeydoğu Diyarbakır, Güneydoğu Anadolu) Tektonik Evriminin Sismik Veriler, Kuyu Logları ve Arazi Gözlemleri İle İncelenmesi

Abstract

The Hazro High in the Southeastern Anatolia is located in an area where the Arabian Plate and the Anatolian Plate are interlocked, and a NW-SE trending asymmetrical anticline with a reverse fault in the south. The other significant highs in the Southeastern Anatolia, which are the Mardin and Siirt highs have controlled the sedimentary succession of the entire region from Paleozoic to Cretaceous. In addition, there should be either a long nonsedimentation time or erosion due to relative rift-related-rise occurring during the opening of the southern branch of the Neotethys Ocean during the Triassic period. While the Lower Triassic age Uludere Formation, belonging to the Çığlı Group, overlain the Tanin Group, which is the Permian age deposits in Southeastern Anatolia, is observed in the wells and the surface, there is no Middle or Late Triassic deposits observed. In order to better understand the tectonic evolution of the Hazro High, besides the field observations, 10 wells drilled for hydrocarbon exploration have been evaluated for the stratigraphy of the High and possible faults. In addition, nine seismic lines that are approximately perpendicular to the ascent axis are interpreted. The oldest unit observed in the wells is the Middle-Upper Ordovician age Bedinan Formation, and the sands in it also a reservoir rock in the region. The Lower Silurian-Lower Devonian aged Dadaş Formation is the oldest unit that outcrops on the High and is of the source rock character. The Lower Devonian Hazro Formation is also a reservoir rock, overlies the Dadaş Formation. The units of the Permian age Tanin Group overlies the Hazro Formation. The Lower Triassic Uludere Formation of the Çığlı Group overlies the Tanin Group. While the Jurassic units are not observed on the High, the Lower Santonian-Lower Campanian aged Mardin Group overlies the Uludere Formation. The Derdere Formation, one of the most important reservoir rocks in the Southeastern Anatolia region, belongs to the Mardin Group. The Upper Campanian aged Sayındere Formation overlies the Mardin Group. The Sayındere Formation is composed of clayey limestone rocks and it is a cap rock for the Mardin Group. The Upper Campanian- Middle Maastrichtian aged Kastel Formation overlies the Sayındere Formation on the High. The Paleocene aged Antak Formation overlies The Sayındere Formation, Kastel Formation or Mardin Group in different parts of the High. While the Eocene-Oligocene Hoya Formation belonging to Midyat Group overlies the Antak Formation, Lower Miocene aged Fırat Formation covers Antak Formation. The Middle- Upper Miocene aged Şelmo Formation overlies the The Fırat Formation. Although the limestones of the Midyat Group and the Fırat Formation have been substantially protected the High against erosion, due to the erosion of these limestones near the Hazro District the Dadaş Formation is exposed. The reverse fault juxtaposes the Dadaş Formation and the Uludere Formation, the Mardin Group at the core of the High is Cretaceous age, and it has been reactivated in the Tertiary tectonics. The Hazro Reverse Fault juxtaposes the Midyat Group and the Fırat Formation with the Şelmo Formation in the south of the High is Tertiary age and goes down to Paleozoic units according to seismic interpretation. While the Antak Formation overlain the Karadut Complex, the Kastel and the Sayındere formations in the northern limb of the High, it is directly overlain the Mardin Group in the southern limb due to the erosion of the Kastel and the Sayındere formations. The horizontal movements in the Lower Maastrichtian affected the High, however unlike the south; it gained its current direction, which is NW-SE by rotating in the SW-NE Upper Cretaceous movement where there is more severe folding and exposing. The movement that led to this rotation appeared before the Mardin Group and a NW-SE trending high was repeated in the Upper Cretaceous. The direction of the Hazro Reverse Fault is parallel to the Bozova and the Mardin Highs, the other current highs in the region. However, the Triassic sequence, which is seen thicker in both the west and the east of the Hazro High, the fact that it was thinned in the Hazro High, indicates that an older high existed before the Mardin Group.