Late Eocene-Early Miocene Palaeogeographic Evolution of Central Eastern Anatolian Basins, the Closure of the Neo-Tethys Ocean and Continental Collision

Abstract

In central eastern Anatolia which is located between Eurasia and Africa, the study of basin developments between late Eocene and early Miocene is of great importance for understanding the process of the closure of the Neo-Tethys Ocean and the formation of strike-slip faults and regional uplift. To study these, three basins were selected: the Sivas-Erzincan, Gürün-Akkisla-Divrigi (GAD), and Malatya basins. The study proposes that the opening of the GAD basin played a key role in the formation of the Ecemis fault, which started developing at the end of early Miocene, and in mountain uplift. All these basins are situated on continental blocks and oceanic crust, arranged from north to south as the Sakarya continent, the Izmir-Ankara-Erzincan ocean (Northern Neo-Tethys), the Kirsehir continent, the inner Tauride ocean, the Munzur-Binboga block, the Maden (=Berit) ocean, the Bitlis-Pütürge block, the Çüngüs ocean and the Arabian continent. The findings indicate that late Eocene-early Miocene successions in these basins were not deposited in foreland basins formed in front of the thrust faults associated with the closure of the ocean, as stated in previous studies. Rather, they were deposited in forearc and backarc basins related to the subduction which was effective until the end of early Miocene. The Sivas-Erzincan and Malatya basins, located on the inner Tauride and Maden (=Berit) oceans, were forearc basins, while the GAD basin situated on the Munzur-Binboga block was a backarc basin. These basins have parallel developments up to the end of early Miocene. While marine sediments were deposited in the Malatya and Sivas-Erzincan basins between late Eocene and early Miocene, terrestrial units began to settle in the GAD basin from the late Eocene and the deposition there is continuous until the end of the early Miocene. Collision of the Arabian and the Anatolian plates at the end of early Miocene (16-18 Ma) produced the left-strike slip Ecemis fault zone, which caused the lateral slip of sedimentary units in the Sivas-Erzincan and GAD basins over hundreds of kilometers. This event produced the first westward tectonic escape of the Anatolian plate prior to the north Anatolian fault (NAF) and the east Anatolian fault (EAF). The Gürün region located in the GAD basin was exhumed in late Miocene and this basin was broken. The Gürün region, which remains on the rising part of the Munzur-Binboga block, is not a different basin as stated earlier, but it is a part of the GAD basin, representing the central part of the GAD basin lake, as indicated by the fine grained deposits (limestones and clay) that occur in the Gürün area.

Generation of collision-induced Early to Middle Miocene adakitic magmas in Pertek (Tunceli) area from Eastern Anatolia postsubductional setting, Turkey

“…Similarly, Topuz et al (2019) suggested that the Early Miocene represents probably a time of continental extension and exhumation in Eastern Anatolia and NW Iran. However, recent studies (e.g., Karadenizli et al, 2016;Gülyüz et al, 2020) confirm the Miocene time of collision between Eurasian and Arabian plates, which are also consistent with the proposed model of Okay et al (2010) and Cavazza et al (2018).…”

“…The timing of the initiation of continental collision between the Arabian and Eurasian plates is still debated. Contrary to the view of Early to Middle Miocene (Okay et al, 2010;Karadenizli et al, 2016;Açlan and Altun, 2018;Gülyüz et al, 2020) and Middle Miocene periods (Cavazza et al, 2018) for the onset of collision, van Hunen andAllen (2011), McQuarrie andvan Hinsbergen (2013) and Koshnaw et al (2017) advocated that by Middle Oligocene (~ 26 -Ma), Neo-Tethys oceanic crust had been consumed, and the Arabia-Eurasia continentcontinent collision initiated. On the other hand, for the Caucasus-Iran-Anatolia (CIA) collisional zone volcanism, Lin et al (2020), proposed a double subduction scenario (e.g., Skobeltsyn et al, 2014) and double slab break-off model (Erzurum-Kars Suture Zone in Pontide at North, Bitlis-Zagros Suture Zone in SE Anatolia at South), and suggested that break-off events occurred at ≈ 17 Ma (Early Miocene) at South (Bitlis-Zagros Suture Zone) and ≈ 9 Ma at North (Erzurum-Kars Suture Zone).…”

“…Based on anisotropy data of magnetic susceptibility of the dated sedimentary sequences from East Anatolia, Gülyüz et al (2020) contend that the Early to Middle Miocene period marks the onset of continental (hard) collision between Eurasia and Arabia and the initiation of collision-related uplift in the region. Similarly, Karadenizli et al (2016) suggested the end of Early Miocene time for the collision of Arabian and Anatolian plates, based on the basin analysis of Central Eastern Anatolia. In this regard, a significant crustal thickening in the region during the Early to Middle Miocene magmatism can be expected, and infer from using La/Yb ratios (cf.…”

Late Miocene−early Pliocene rodents and lagomorphs (Mammalia) from the southern part of Çankırı Basin, Turkey

“…The suture zone is marked by an ophiolitic belt that extends all along the southern margin of the Sakarya block and Pontid belt, which are parts of the Eurasian continent. Consecutive to this collision, a large marine foreland depression formed south of this suture zone during the Paleogene, and this depression became fragmented during the late Paleogene and Neogene under the neotectonic regime to form the main Central Anatolian basins—from west to east Beypazarı, Haymana-Polatlı, Tuzgölü, Çankırı, and Sivas basins (Görür et al, 1998; Görür and Tüysüz, 2001; Huvaz, 2009; Karadenizli et al, 2016; Poisson et al, 2016).…”

Paleoenvironments of the Cappadocia region during the Neogene and Quaternary, central Turkey

“…6a) in the sequence representing dynamic sedimentation under high energetic conditions most likely controlled by regional tectonics that caused relief changes in the surrounding topography. Earlier activity on the Ecemiş Fault of the Central Anatolian Fault Zone was proposed as the end of early Miocene by some researchers (e.g., Karadenizli et al 2016) that coincide with this period. The available middle Miocene mammal fauna are represented by small forms (i.e., Rodentia, Insectivora and Lagomorpha; Fig.…”