Palaeozoic-Recent geological development and uplift of the Amanos Mountains (S Turkey) in the critically located northwesternmost corner of the Arabian continent

<p>We have carried out a several-year-long study of the Amanos Mountains, on the basis of which we present new sedimentary and structural evidence, which we combine with existing data, to produce the first comprehensive synthesis in the regional geological setting. The ca. N-S-trending Amanos Mountains are located at the northwesternmost edge of the Arabian plate, near the intersection of the African and Eurasian plates. Mixed siliciclastic-carbonate sediments accumulated on the north-Gondwana margin during the Palaeozoic. Triassic rift-related sedimentation was followed by platform carbonate deposition during Jurassic-Cretaceous. Late Cretaceous was characterised by platform collapse and southward emplacement of melanges and a supra-subduction zone ophiolite. Latest Cretaceous transgressive shallow-water carbonates gave way to deeper-water deposits during Palaeocene-Eocene. Eocene southward compression, reflecting initial collision, resulted in open folding, reverse faulting and duplexing. Fluvial, lagoonal and shallow-marine carbonates accumulated during Late Oligocene(?)-Early Miocene, associated with basaltic magmatism. Intensifying collision during Mid-Miocene initiated a foreland basin that then infilled with deep-water siliciclastic gravity flows. Late Miocene-Early Pliocene compression created mountain-sized folds and thrusts, verging E in the north but SE in the south. The resulting surface uplift triggered deposition of huge alluvial outwash fans in the west. Smaller alluvial fans formed along both mountain flanks during the Pleistocene after major surface uplift ended. Pliocene-Pleistocene alluvium was tilted towards the mountain front in the west. Strike-slip/transtension along the East Anatolian Transform Fault and localised sub-horizontal Quaternary basaltic volcanism in the region reflect regional transtension during Late Pliocene-Pleistocene (<4 Ma).</p

Early pliocene molluscs from the easternmost Mediterranean region (SE Turkey): Biostratigraphic, ecostratigraphic, and palaeobiogeographic implications

The mollusc faunas from Pliocene deposits of the Hatay-İskenderun region were investigated at nine localities and complemented with three localities from earlier studies. The Pliocene units were deposited in three adjacent subbasins, Hatay-Samandağ (HS), Altınözü-Babatorun (AB), and İskenderun-Arsuz (İA); the first two are also known as the Hatay Graben. Basin configurations and shape, environmental evolution, and faunal compositions were affected by differential tectonic histories since the Late Miocene. In total 162 species (94 gastropod, 61 bivalve, and 7 scaphopod) are recorded, 80 of which are recorded for the first time from the region. The occurrence of tropical stenohaline benthic taxa (such as Persististrombus coronatus and some conid gastropod species) and a number of chronostratigraphically well-constrained mollusc species shows a Zanclean age. The base of the Early Pliocene is also shown by the occurrence of planktic foraminifer assemblages corresponding to MPL1 and MPL2 biozones and the nannoplankton Amaurolithus delicatus assemblage. The Early Pliocene Hatay molluscan assemblages allow for palaeobiogeographic comparisons across the Mediterranean. The Pliocene marine fossiliferous deposits are assigned to the Mediterranean Pliocene Molluscan Unit 1 (MPMU1) of the western Mediterranean and Atlantic regions. However, the eastern Mediterranean assemblages are notably poorer in species and in particular a number of thermophilic groups are lacking. This marine biodiversity gradient has been a characteristic feature of the Mediterranean ever since the Pliocene. © TÜBİTAK

Pre-and post-deposition stages of messinian evaporites based on facies interpretations in the Hatay Graben and its sub-basins, southeastern Turkey

The Hatay Graben (HG), divided into two sub-basins, Hatay-Samandağ (HS) and Altınözü-Babatorun (AB) consists of very typical deposits of the pre-and post-evaporite stages spaning to the latest Tortonian/early Messinian to Zanclean time. In the graben center (HG/HS), pre-evaporite stage starts with an environmental shallowing episode following deeper sea turbidites (FN1) deposited during early-middle Tortonian time. The basinal shallowing episode trigerred by the late Tortonian tectonics, had involved a siliciclastic-dominated accumulation of coastal sands, small-size fan/Gilbert-type deltas, braided rivers, and f uvial incices and Melanopsis-bearing mudstone (L1), and these kinds of deposition collectivelly reflec a deposition under the estuarine-brackish (oligohaline) conditions (FN2–4). However, in some places (e.g., Hancağız), some pteripod-bearing sandy mudstones and grey mudstones are present within the shallow marine-estuarine/brackish (oligohaline) associations, indicating that relatively deeper environmental conditions, that were temporaly developed within the pre-evaporite succession. The pre-evaporitic environmental f uctutations from brackish to marine was ended by an evaporite-precipitated stage (Vakıf ı Formation), where the gypsum dominated evaporites (FV1) were deposited in the marginal basins as upper gypsum. They are fault-controlled iso-lated/mini basins represented by bedded-selenitic gypsum, mudstone-alternating laminated gysum and locally slumped gypsum. The evaporitic stage was terminated by gyrogonites-bearing mudstone (FV2), which is marked by L2 assigned to the establisment of the second stage estuarine/brackish (oligohaline) environment. In Kuşalanı district, some sandy mudstones that are time equivalent of the FV2, composed of a few Paratethyan mollusk species such as melanopsids, dreissenids and lymno-cardiids that can be tentatively considered as Lago-Mare type deposits formed after the Messinian evaporite stage. Subsequently, Zanclean marine ref ooding was distinguished by different kinds of sediments (e.g., Samandağ Fm), but it is generally onset of the coarse-grained delta, fan/Gilbert-types and followed upward by the wave-tidal-storm-dominated shallow water silisiciclastics (FS1–8), suggesting the graben/basin margin was subjected to a catastrophic or fast marine ref ooding after the MES. In the Graben center, there has not been any clear boundary between the Messinian/Zanclean succesions. In Hancağız section, gypsum blocks (FN 5) beneath Zanclean deposits may be evidence of Messinian Erosion Surface (MES); however, there is no notable time gap between the Miocene and Pliocene units that can be attributed to conformity or low-grade disconformity. This sitution is contrasting to the graben-margin setting, represented by erosional unconformity, where Zanclean deposits sit directly on the Tortonian turbidite unit, lacking upper Tortonian shallow water siliciclastics and Messinian evaporite. This resulted in a late Tortonian tectonics phase (sensu lato: Tortonian erosion surface “TES”). At the same time this evolved a new basin, Altınözü-Babatorun (AB) which is differentiated from the neighboring subbasins by means of its own depositional character represented by alternations of Zanclean shallow water sandstones and pelagic limestone beds or pelagic sills and dykes within the sandy matrix. © 2019 E. Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, German

Spatial slip behavior of large strike-slip fault belts: Implications for the Holocene slip rates of the eastern termination of the North Anatolian Fault, Turkey

We present new data on Holocene slip rates for the eastern end of the North Anatolian Fault (NAF) by using the optically stimulated luminescence ages of the offset terrace deposits at two sites, where a total of four displaced landforms was studied. Each offset feature was analyzed independently, and three different assumptions were made for all the offsets, depending on whether the age of the upper tread (upper tread reconstruction), the lower tread (lower tread reconstruction), or all bounding surfaces (intermediate solution) were used in dating of the terrace risers. The deflected geometry of the risers strongly suggests the use of either the intermediate solution or the upper tread reconstruction. The joint slip rate distributions for the upper tread reconstructions and the intermediate solutions were modeled as 13.0 + 1.8 / 1.4 and 14.3 + 5.8 / 2.4 mm/yr (2σ), respectively. Although the intermediate solution covers the full range of ages for the measured displacements, the curved geometry of the terrace risers suggests that the initiations of the riser offsets are most probably close to the abandonment ages of the upper terrace treads. Therefore, we accepted the joint slip rate of the intermediate solution but suggested that the average rate for the main displacement zone of the eastern NAF should be close to its lower limits. This slower rate with respect to previous estimates suggests that the total deformation is not only accommodated on the main displacement zone but is also distributed along the secondary faults to the south of the easternmost segments of the NA

Mechanics of plio-quaternary faulting around the Karliova triple junction: implications for the deformation of Eastern part of the Anatolian Scholle

The intersection of the Eurasian and Arabian plates and the smaller Anatolian Scholle created the Karlıova Triple Junction (KTJ) in eastern Turkey. In this study, we present analogue model experiments for this region and compare the results with our field observations and data from remote sensing imagery. Our comparison suggests that the sense of slip along curvilinear faults at the west of the KTJ changes along strike moving away from the principal displacement zones, from strike-slip to oblique normal and then to pure normal slip. Although, the active Prandtl cell model has been proposed to explain the overall regional fault pattern at eastern part of the Anatolian Scholle, the map view orientation of the secondary faults within the Karlıova wedge and performed analogue modelling results suggest that the passive wedgeshaped Prandtl cell model with a normal dip-slip component along slip lines is more appropriate in order to explain not only deformation pattern around the KTJ but also internal deformation of eastern part of the Anatolia. Moreover, these faults accumulate the significant amount of deformation that causes to the irregular earthquake behavior and the relatively lower geologic slip-rates along the main fault branch of boundary faults around the KTJ

Rapid early-middle Miocene exhumation of the Kazdag Massif (western Anatolia)

Apatite fission-track analyses indicate that the Kazdag. Massif in northwestern Anatolia was exhumed above the apatite partial annealing zone between 20 and 10 Ma (i.e. early-middle Miocene), with a cluster of ages at 17-14 Ma. The structural analysis of low-angle shear zones, high-angle normal faults and strike-slip faults, as well as stratigraphic analysis of upper-plate sedimentary successions and previous radiometric ages, point to a two-stage structural evolution of the massif. The first stage encompassing much of the rapid thermal evolution of the massif-comprised late Oligocene-early Miocene low-angle detachment faulting and the associated development of small supradetachment grabens filled with a mixture of epiclastic, volcaniclastic and volcanic rocks (Kucukkuyu Fm.). The second stage (Plio-Quaternary) has been dominated by (i) strike-slip faulting related to the westward propagation of the North Anatolian fault system and (ii) normal faulting associated with present-day extension. This later stage affected the distribution of fission-track ages but did not have a component of vertical (normal) movement large enough to exhume a new partial annealing zone. The thermochronological data presented here support the notion that Neogene extensional tectonism in the northern Aegean region has been episodic, with accelerated pulses in the early-middle Miocene and Plio-Quaternary