Magnetostratigraphy and paleoecology of the hominid-bearing locality Çorakyerler, Tuglu Formation (Çankiri Basin, Central Anatolia)

Peer reviewe

Kinematic and thermal evolution of the Haymana Basin, a fore-arc to foreland basin in Central Anatolia (Turkey)

Gondwana (Tauride/Kırşehir blocks) and Eurasia (Pontides) derived continental blocks delimit the Haymana basin, central Turkey, to the south and the north, respectively. The boundaries of these blocks define the Izmir-Ankara-Erzincan and Intra-Tauride Suture zones which are straddled by a number of Late Cretaceous to Oligocene marine to continental basins. The Haymana Basin is located at the junction of the IAESZ and ITSZ and comprises Upper Cretaceous to Middle Eocene basin infill deposited in response to the interaction of these blocks. The basin provides a unique opportunity to unravel spatio-temporal relationships related to the timing of late stage subduction history of Neo-Tethys Ocean and subsequent collision of the intervening continental blocks. We have conducted a multidisciplinary study in the region that includes mapping of major structures combined with fault kinematic analyses. E-W striking folds dominate the basin, cross-section balancing of these structures indicates around 25% roughly N-S shortening in the region. Paleostress studies indicate that the basin was initially subjected to N-S to NNE-SSW extension until the middle Paleocene (phase 1) and then N-S directed syn-depositional compression and coeval E-W directed extension until the middle Miocene (phase 2) implying strike-slip deformation and pure shear shortening in the basin. These different deformation phases are attributed to first fore-arc (subduction) basin development then foreland (collision) stages of the basin. Apatite (U-Th)/He dating of 5 samples indicate that exhumation of the SE segment of the basin started in early Oligocene, whereas the NW segment of the basin exhumed in the early Miocene. The differential uplift is possibly related to progressive north-westwards movement of Dereköy basin bounding fault at the north. We propose that the Haymana basin evolved from extensional forearc basin during the late Cretaceous to early Paleocene and foreland basin after the terminal subduction and subsequent collision of Tauride and Pontide blocks

Miocene geochronology and stratigraphy of western Anatolia:Insights from new Ar/Ar dataset

Understanding the dynamic evolution of orogenic belts and intra-continental basins depend on field-based (tectono-) stratigraphic observations paired with geochronologic data such as 40Ar/39Ar analyses. Independent dating of tectono-stratigraphic units is a crucial tool to place them in a broader framework. In this study, we focus on the geodynamic development of western Anatolia, with an emphasis on the timing and progression of volcanism along the İzmir-Balıkesir Transfer Zone (İBTZ). We present 36 new 40Ar/39Ar ages of both volcanic complexes/domes and volcanic rocks coevally emplaced within Miocene sediments from western Anatolian extensional basins. In combination with existing ages from the literature and paleontological records from Miocene basin in-fills, we build an improved and integrated stratigraphic framework for the region. Our results show a remarkable break in volcanism from this area during the Langhian (15.97–13.82 Ma), encompassing a major unconformity in the İBTZ, and a pulse in the exhumation of metamorphic core complexes in western Anatolia. Hence we attribute this magmatic pause to the tectonic reorganization and change in the partitioning of extensional deformation between Cycladic and Menderes core complexes, facilitated by the acceleration of roll-back of African oceanic lithosphere below western Anatolia

Miocene geochronology and stratigraphy of western Anatolia : Insights from new Ar/Ar dataset

Understanding the dynamic evolution of orogenic belts and intra-continental basins depend on field-based (tectono-) stratigraphic observations paired with geochronologic data such as 40Ar/39Ar analyses. Independent dating of tectono-stratigraphic units is a crucial tool to place them in a broader framework. In this study, we focus on the geodynamic development of western Anatolia, with an emphasis on the timing and progression of volcanism along the İzmir-Balıkesir Transfer Zone (İBTZ). We present 36 new 40Ar/39Ar ages of both volcanic complexes/domes and volcanic rocks coevally emplaced within Miocene sediments from western Anatolian extensional basins. In combination with existing ages from the literature and paleontological records from Miocene basin in-fills, we build an improved and integrated stratigraphic framework for the region. Our results show a remarkable break in volcanism from this area during the Langhian (15.97–13.82 Ma), encompassing a major unconformity in the İBTZ, and a pulse in the exhumation of metamorphic core complexes in western Anatolia. Hence we attribute this magmatic pause to the tectonic reorganization and change in the partitioning of extensional deformation between Cycladic and Menderes core complexes, facilitated by the acceleration of roll-back of African oceanic lithosphere below western Anatolia