Titanite and zircon fission-track dating resolves successive igneous episodes in the formation of the composite Kaçkar batholith in the Turkish eastern Pontides

The Kaçkar batholith in the Turkish eastern Pontides comprises several intrusive units with distinctive textural, mineralogical and geochemical characteristics. Their titanite and zircon fission-track ages confirm that the different lithodem units result from consecutive igneous episodes, establish their emplacement sequence and, together with geochemical data, help to relate them to their geodynamic context. The Çaml?kaya granitoid (112.4 ± 1.6 Ma) was emplaced during an immature-arc magmatic episode of early Cretaceous age. The S?rtyayla (57.1 ± 1.2 Ma) and Marselevat (52.9 ± 1.3 Ma) granitoids are late products of a late-Palaeocene mature-arc episode. The Ayder granitoid (46.4 ± 1.0 Ma) is the result of middle- to late-Eocene post-collisional magmatism related to slab break-off. The Halkal?ta? quartz diorite (43.7 ± 2.3 Ma) and the Güllüba? monzonite (38.1 ± 0.9 Ma) document a middle- to late-Eocene episode related to post-collisional extension. The data reveal the advantages of dense sampling, spanning a maximum range of elevations. Apart from the increased precision on the mean, redundant sampling allows to shift the basis for interpretation from a priori assumptions to a posteriori numerical criteria when using geochronometers with low to moderate closure temperatures, including apatite, titanite and zircon fission-tracks but also K–Ar (Ar–Ar) biotite, muscovite and K-feldspar.     

Biostratigraphic interpretation and systematics of Alveolina assemblages from the Ilerdian–Cuisian limestones of Southern Eskişehir, Central Turkey

The Ilerdian–Middle Cuisian sedimentary succession of the Seyitgazi region, southern Eskişehir (Central Anatolia, Turkey) is composed of claystones, limestones and clayey limestones. It contains abundant benthic foraminifera, particularly species of Alveolina. From this succession, 28 species of Alveolina d’Orbigny are described and their comparative stratigraphic distribution with the Alveolina species in the Tethyan Eocene is documented. Generally, Ilerdian–Cuisian Alveolina assemblages of the Seyitgazi region have close affinities with coeval Alveolina assemblages described in different studies from the Tethyan Province. The Ilerdian unit of the study area is characterized by Alveolina species such as Glomalveolina lepidula, Glomalveolina minutula, G. karsica, Alveolina vredenburgi, A. ellipsoidalis, A. avellana, A. aff. minervensis, A. dedolia, A. moussoulensis, A. subpyrenaica, A. laxa, A. aragonensis, A. varians, A. ilerdensis, A. trempina, A. citrea, A. pisella and A. decipiens. Likewise, the Early Middle Cuisian unit is represented by G. minutula, A. oblonga, A. schwageri, A. haymanensis, A. canavarii, A. aff. coudurensis, A. ruetimeyeri, A. muscatensis, A. cremae, A. bayburtensis and A. lehneri.     

Finger prints of the formation of geothermal springs on the granitoids: Beypazarı–Ankara, Turkey

The Beypazarı granitoid in central Anatolia was emplaced during the Late Cretaceous and it is partly covered with Early Miocene–Quaternary sedimentary and volcanic units. Compression and tension regimes of the Beypazarı granitoid emplacing along the Sakarya River were evaluated considering the kinematical characteristics of discontinuities on granitoids, petrographic/geochemical works, formation of geothermal spring and irregularities in topographic structure. It was determined that the Beypazarı granitoid was witnessed with NE–SW compressional stress and NW–SE extensional stress which resulted in the formation of the Kapullu normal fault with N55–72°E, 78°SE crossing the Kapullu spring site. There are also several other probable normal faults around this fault in the Sakarya River basin. The results of the geochemical studies reveal that SiO₂, Na₂O, Al₂O_3, CaO and K₂O as a major oxide and As, Rb, Sr, Th and U as trace elements are decreased away from the Kapullu bath spring. On the other hand, the ratio of Fe₂O₃ and MgO as major oxide and Y as a trace element with the lost on ignition (LOI) are increased away from the Kapullu fault. Regard as the regional plate tectonism, there is a consistency between the direction of compression in the Beypazarı granitoid and that developed by the southwesterly movement of the Anatolian plate.     

Settlement behaviour of a concrete faced rock-fill dam

Settlement behaviour of a concrete faced rock-fill dam (CFRD), Kurtun dam, located in the East Black Sea Region, Turkey, is investigated. This is the first instrumented CRDF in the Country. Two dimensional plane strain finite element analyses were carried out to assess the total stresses and displacements in the dam both for construction and reservoir filling stages by using computer program PLAXIS. Predicted stresses and settlements are compared with those observed and overall the results are found to be in good agreement for the construction stage. Due to the relatively steep abutment slopes, cross-valley arching has a significant effect on stresses and displacements in the dam body. For the reservoir filling condition, it is seen that, predicted settlements are larger than the observed values, which indicates that during reservoir filling the rock-fill embankment responds more stiffly than it does during the construction stage. The hardening soil model is used to represent the non-linear, inelastic and stress dependent behaviour of rock-fill material. The model parameters are selected from the appropriate values in the literature investigating comparable cases.     

Consistent formulation of direct and substructure methods in nonlinear soil-structure interaction

Both direct and substructure methods of dynamic soil-structure interaction analysis can be treated using a common analytical model with difference being restricted only to the definition of boundary conditions of the bounded soil zone. It is shown that a consistent formulation of the problem equally applicable to both methods can be achieved in which true nonlinear behaviour of the bounded soil zone (near-field) can be taken into account in the time domain through properly defined constitutive models. However, for the linear boundary conditions to be imposed on the near-field inevitably involves the application of the principle of superposition resulting in a linear far-field approximation. Therefore, the bounded soil zone taken should be large enough in both methods to reduce the adverse effects of the far-field linearization.     

A new tsunami runup predictor

Natural Hazards - We introduce a new parameter, tsunami runup predictor (TRP), relating the accelerating phase of the wave to the length of the beach slope over which the wave is travelling. We...     

Evolution of Çamlık fissure-ridge travertines in the Başkale basin (Van,Eastern Anatolia)

Fissure-ridge travertines (FRTs) are of great importance for the determination and comparison of tectonic deformation in a region. The coeval development of these travertines with active fault zones supplies significant information about regional dynamics in terms of deformation pattern and evolution. In this paper, the characteristics of FRTs of the Ba?kale basin (eastern Turkey) and responsible regional tectonism are discussed for the first time. The Ba?kale basin is located between the Ba?kale Fault Zone (BFZ) characterised by Çaml?k fault and I??kl?–Zirani? fault. It is located between dextral Yüksekova Fault Zone and southern end of dextral Guilato–Siahcheshmeh–Khoy Fault system (Iran). Various morphological features indicating recent activity are exposed along the BFZ, including offsetting rivers, fissure-ridge travertine and fault scarps. The Çaml?k fissure-ridge travertine composing of three different depositions is observed along the eastern edge of the BFZ with approximately parallel orientations. The Çaml?k fissure-ridge travertine has been formed and developed on fault zone related to strike-slip or oblique movements. We explain how kinematic changes of faults can influence the fissure-ridge development.     

Chemometric approach integrated with capillary electrophoresis for the investigation of public water system sources and quality

A chemometric approach coupled with capillary electrophoresis based on the hierarchical cluster analysis and principal component analysis has been applied for the investigation of the water quality in the Golcuk-Isparta region (Lake District of Turkey). In the research area, Egirdir Lake, Golcuk Lake and surrounding ground and domestic waters have been utilized as drinking water resources. Golcuk Lake is distinctive in terms of high fluoride content (3.50 ± 0.21 mg/mL) which is endemic in volcanic areas where the water flow through volcanic rocks and sediments. Based on the analysis of major anions chloride, sulfate, nitrate and fluoride with capillary electrophoresis, twenty-four drinking water sampling sites in the research area were classified into four classes using the hierarchical cluster and principal component analysis. Combining the research area investigation results of hierarchical cluster and principal component analysis, it was found that fluoride concentration is the major diagnostic variable to determine the quality of drinking waters, and all the other anions are the important classification factors to predict the resources of the drinking water samples, individually. To sum up, this study reveals the potential of the use of capillary electrophoresis in combination with chemometric techniques for the determination of the quality and origin of drinking waters.     

Heavy metal contamination in surface sediments of Gökçekaya Dam Lake,Eskişehir,Turkey

The present study to find seasonal (September 2010–June 2011) heavy metal (Cd, Pb, Cr, Co, Ni, Zn, Cu, Fe, As) contamination and the origins thereof in surface sediments of Gökçekaya Dam Lake, as constructed on Sakarya River, the third-longest river in Turkey and the largest river of the Northwestern Anatolia. Upon analyses for the purpose thereof, heavy metal contamination in annual average concentrations in the lake sediment varied, respectively, as Fe > Zn > Cr > Ni > Cu > Pb > Co > As > Cd. Statistical assessments performed in order to see whether the average values of the heavy metal contamination as measured at stations placed in the lake changed by seasonal periods. There found statistically significant differences especially in Cd, Zn, and Pb between seasonal periods. In accordance with the Sediment Quality Index, Gökçekaya Dam Lake sediment was classified as “highly polluted” in terms of the amount of anthropogenic contaminants of As, Cr, Cu, Ni, Pb, and Zn. Enrichment factor and geoaccumulation index values (I _geo) were calculated in order to geochemically interpret the source of contamination due to heavy metal concentration in the lake sediment and the level of pollution. The As, Co, Cr, Cu, Ni Pb, and Zn values demonstrated that the sediment was rich for anthropogenic contaminants. The lake was found especially rich for arsenic (14.97–34.70 mg/kg) and lead (68.75–98.65 mg/kg) in accordance with annual average values. In general the lake was geochemically characterized as “moderately contaminated” in terms of As, Co, Cr, Cu, Ni, Pb, and Zn content.