İzmir‐Ankara suture as a Triassic to Cretaceous plate boundary – data from central Anatolia

The İzmir‐Ankara suture represents part of the boundary between Laurasia and Gondwana along which a wide Tethyan ocean was subducted. In northwest Turkey, it is associated with distinct oceanic subduction‐accretion complexes of Late Triassic, Jurassic and Late Cretaceous ages. The Late Triassic and Jurassic accretion complexes consist predominantly of basalt with lesser amounts of shale, limestone, chert, Permian (274 Ma zircon U‐Pb age) metagabbro and serpentinite, which have undergone greenschist facies metamorphism. Ar‐Ar muscovite ages from the phyllites range from 210 Ma down to 145 Ma with a broad southward younging. The Late Cretaceous subduction‐accretion complex, the ophiolitic mélange, consists of basalt, radiolarian chert, shale and minor amounts of recrystallized limestone, serpentinite and greywacke, showing various degrees of blueschist facies metamorphism and penetrative deformation. Ar‐Ar phengite ages from two blueschist metabasites are ca. 80 Ma (Campanian). The ophiolitic mélange includes large Jurassic peridotite‐gabbro bodies with plagiogranites with ca. 180 Ma U‐Pb zircon ages. Geochronological and geological data show that Permian to Cretaceous oceanic lithosphere was subducted north under the Pontides from the Late Triassic to the Late Cretaceous. This period was characterized generally by subduction‐accretion, except in the Early Cretaceous, when subduction‐erosion took place. In the Sakarya segment all the subduction accretion complexes, as well as the adjacent continental sequences, are unconformably overlain by Lower Eocene red beds. This, along with the stratigraphy of the Sakarya Zone indicate that the hard collision between the Sakarya Zone and the Anatolide‐Tauride Block took place in Paleocene

Uplift of Anatolia

The Cenozoic history of the Anatolian Plateau is investigated using the distribution of the last Cenozoic marine strata, the ages of Neogene continental sediments and magmatic rocks, and thermochronology. In central and northern Anatolia, the youngest marine sediments are of Middle Eocene age and show that the region has been above the sea level since ca. 41 Ma. The preservation of marine Eocene sequences over large regions and widespread distribution of Neogene continental sediments point to minor erosion or subsidence, except in the Miocene core complexes, and indicate average surface uplift or subsidence rates of less than 0.05 km/Myr since 41 Ma. The Cenozoic mammal ages point to widespread continental deposition on the Anatolian Plateau from Early Miocene (ca. 22 Ma) to the present, and a similar pattern of semicontinuous magmatism has been observed in Anatolia since ca. 23 Ma. New thermochronological data from central Anatolia to west of Ankara have indicate a major exhumation phase during the Paleocene and Early Eocene, followed by minor uplift and/or subsidence. Miocene exhumation is restricted to the core complexes, such as the Kazda\u11f Massif. The Anatolian Plateau has been a land area since 41 Ma and was characterized by continental sedimentation and volcanism in the last 22 Myr. In this period, subsidence and uplift were balanced so that central Anatolia was maintained above sea level. In contrast, its southern mountainous margin, the Taurides, is free of Neogene magmatism and has undergone a fast uplift above sea level since 8 Ma (ca. 0.3 km/Myr). These differences indicate that the uplift of Anatolia cannot be ascribed to a single mechanism. Flat subduction, followed by mantle upwelling under Anatolia in the post-Middle Eocene period, maintained the region above the sea level, whereas the Late Miocene rupture of the subducting eastern Mediterranean oceanic slab have induced fast uplift of the Taurides

Relation between sarcopenia and dose-limiting toxicity in patients with metastatic colorectal cancer who received regorafenib

PMID = 3086838