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

Different Test Forms and Numerous Apertures of Cibicidella variabilis (d’Orbigny) from The Turkish Coast of Eastern Aegean Sea

In the last ten years, morphological abnormalities and colored tests have been observed in benthic foraminifera specimens collected from Aegean and Southwestern coasts of Turkey. Specific morphological abnormalities show distinct distribution patterns, suggesting the need for special environmental conditions facilitating the development of such abnormalities. Physical and chemical parameters have been proposed to be responsible for these morphological changes. The benthic foraminifera, Cibicidella variabilis (d’Orbigny) specimens have been collected from different locations on the East Aegean coast of Turkey. Some of them, especially those from Dikili Bay, were found to have variable number of apertures, ranging from one to five. These apertures not structurally, but positionally differ. The abundance of certain test forms in specific locations draws attention. The aim of this study is to determine the possible causes of this aberrant morphology observed in tests of Cibicidella variabilis (d’Orbigny). Cibicidella variabilis (d’Orbigny) shows a wide distribution range on the Aegean coast of Turkey, and has been found in Saros Bay, Gökçeada, Bozcaada, Çanakkale, Edremit Bay, Dikili Bay, Çandarlı Bay, Karaburun Peninsula, Kuşadası, Güllük Bay, Gulf of Gökova, Gulf of Datça, and Marmaris Bay. But, the individuals collected from Gulf of Edremit, Dikili Bay, Çandarlı Bay, Gulf of Gökova, and Gulf of Datça were morphologically different than those collected from the rest of the regions. The variation in the number of apertures, as well as their positions were typical in these samples. Besides, the variations in the shape of the tests observed in adult individuals, but not in juveniles indicates that some environmental factors, which were specific to these regions, might have been involved in this unusual test development. The submarine springs caused by the tectonic activities are typical of the Aegean Sea. It is well documented that these kinds of springs change the characteristics of the surrounding habitat and its fauna. Therefore, it is possible that some of the trace elements, which are abundant in hot spring waters, may be related with the abnormal test morphology observed in our samples. On the other hand, it is also possible that, not only the chemical and physical conditions of the surrounding water, but also its biological properties may affect the test development

Active fault database of Turkey

We have updated the active fault map of Turkey and built its database within GIS environment. In the study, four distinct active fault types, classified according to geochronological criteria and character, were delineated on the 1:25,000 base map of Turkey. 176 fault segments not included in the former active fault map of Turkey, have been identified and documented. We infer that there are 485 single fault segments which are substantially potential seismic sources. In total 1964 active-fault base-maps were transferred into the GIS environment. Each fault was attributed with key parameters such as class, activity, type, length, trend, and attitude of fault plane. The fault parameters are also supported by slip-rate and seismogenic depth inferred from available GPS, seismological and paleoseismological data. Additionally, expected maximum magnitude for each fault segment was estimated by empirical equations. We present the database in a parametric catalogue of fault segments to be of interest in earthquake engineering and seismotectonics. The study provides essential geological and seismological inputs for regional seismic hazard analysis of all over Turkey and its vicinity. © 2016, Springer Science+Business Media Dordrecht.Mount Allison UniversityAcknowledgements This work was carried out as the ‘Updating of Active Fault Map of Turkey and its Database’ project supported by the General Directorate of Mineral Research and Exploration (MTA) between 2004 and 2011. We gratefully acknowledge the MTA for the support provided. Also we would like to thank the reviewers for their comments that improved the paper. The active fault base maps are accessible on the Earth Science Map Portal of the MTA (http://yerbilimleri.mta.gov.tr)

Different Test Forms and Numerous Apertures of Cibicidella variabilis (d’Orbigny) from The Turkish Coast of Eastern Aegean Sea

In the last ten years, morphological abnormalities and colored tests have been observed in benthic foraminifera specimens collected from Aegean and Southwestern coasts of Turkey. Specific morphological abnormalities show distinct distribution patterns, suggesting the need for special environmental conditions facilitating the development of such abnormalities. Physical and chemical parameters have been proposed to be responsible for these morphological changes. The benthic foraminifera, Cibicidella variabilis (d’Orbigny) specimens have been collected from different locations on the East Aegean coast of Turkey. Some of them, especially those from Dikili Bay, were found to have variable number of apertures, ranging from one to five. These apertures not structurally, but positionally differ. The abundance of certain test forms in specific locations draws attention. The aim of this study is to determine the possible causes of this aberrant morphology observed in tests of Cibicidella variabilis (d’Orbigny). Cibicidella variabilis (d’Orbigny) shows a wide distribution range on the Aegean coast of Turkey, and has been found in Saros Bay, Gökçeada, Bozcaada, Çanakkale, Edremit Bay, Dikili Bay, Çandarlı Bay, Karaburun Peninsula, Kuşadası, Güllük Bay, Gulf of Gökova, Gulf of Datça, and Marmaris Bay. But, the individuals collected from Gulf of Edremit, Dikili Bay, Çandarlı Bay, Gulf of Gökova, and Gulf of Datça were morphologically different than those collected from the rest of the regions. The variation in the number of apertures, as well as their positions were typical in these samples. Besides, the variations in the shape of the tests observed in adult individuals, but not in juveniles indicates that some environmental factors, which were specific to these regions, might have been involved in this unusual test development. The submarine springs caused by the tectonic activities are typical of the Aegean Sea. It is well documented that these kinds of springs change the characteristics of the surrounding habitat and its fauna. Therefore, it is possible that some of the trace elements, which are abundant in hot spring waters, may be related with the abnormal test morphology observed in our samples. On the other hand, it is also possible that, not only the chemical and physical conditions of the surrounding water, but also its biological properties may affect the test development

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