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    Application of multivariate statistical approach to identify heavy metal sources in bottom soil of the Seyhan River (Adana), Turkey
    (SPRINGER, 2010) Yalcin, M. Gurhan; Tumuklu, Ali; Sonmez, Mustafa; Erdag, Dilek Satir
    In this study, freshly deposited soils were sampled from the Seyhan River (Turkey) from the exit of the Seyhan Dam to the Adana exit. Heavy metal contents were measured with X-ray fluorescence spectrometer. Multivariate statistical approach is used to identify the sources of heavy metals and other elements in soil samples. Considering the size of anomalies, metals are ranked as Co > Pb > Cr > Zn > Al. Based on the hierarchical cluster analysis results, three clusters were observed. P, Mg, Ti, Fe, Ca, Na, K, Al, Si, and Nb form the first cluster, Zn, Sr, Pb, and Cr associated as the second cluster, and Ba and Co form the third cluster. Three factors computed from principal component analysis are explained with a cumulative variance of 95%. The first factor is defined with "high background lithogenic factor" Co, the second factor with "local industrial factor" Pb, Cr, Ba, and Mg, and the third factor with "natural factor" Cr and Pb.
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    MINERALOGY AND GEOCHEMISTRY OF THE KIZILTEPE (CAMARDI-NIGDE) MN PROSPECT IN CENTRAL ANATOLIA, TURKEY
    (STEF92 TECHNOLOGY LTD, 2016) Lermi, Abdurrahman; Sonmez, Mustafa; Aydin, Faruk
    This paper is to investigate ore-alteration mineralogy and geochemical changes of wall rocks in Kiziltepe Mn mineralization (Camardi, SE-Nigde), which is located in Ulukisla Basin from the central part of the Turkey. Kiziltepe prospect, a fault controlled hydrothermal-type Mn mineralization, is hosted predominantly by Late Cretaceous to Early Tertiary volcanic and volcanoclastic rock series, which are submarine in character with trachytic to rhyolitic composition. After all samples were systematically collected from surface outcrops and the mineralized zones, they were investigated by petrographical and geochemical analysis. The results obtained from the microscopic and XRD analysis showed that the mineralization contained oxi-hydroxide Mn minerals such as manganite, pyrolusite, psilomelane, and manganese phosphate. Quartz, carbonates, sericite, clay minerals and barite are the gangue minerals. Quartz is ubiquitous and occurs both in the ore zone and in the wall rocks. Alteration mineralogy usually was formed fault-related to alteration zones. Alterations were characterized by presence of quartz and sericite, and locally extensively overprinted by kaolinite. Mass change calculations revealed that Al, Ti, and Y behaved as the least mobile elements during alteration and that footwall felsic rocks gained Fe, Si, K, Ca and ore forming constituents, respectively. The most characteristic chemical changes near the ore bodies were the Na depletion, mainly due to plagioclase destruction by the hydrothermal fluids. The BEE contents varied considerably depending on mass change effects related to alteration. An average grade of Mn in the fault zone has been reached about 22.47 %.
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    New evidence concerning to the Nigde fault in the near east and south of the settlement area of the Nigde, central Anatolia, Turkey
    (International Multidisciplinary Scientific Geoconference, 2017) Sonmez, Mustafa; Balli, Fatih; Lermi, Abdurrahman
    The main purpose of this paper is to investigate of the Niğde Fault zone, which passes through the city of Niğde. The study area located in the south and eastern part of the Niğde Province, and crops out different types of geological units from Paleozoic to Cenozoic in that vicinity. These units are, from old to young, metamorphic rocks, which is known as Niğde Massif composed of Gümüşler, Kaleboynu, Aşıgediği formations, Üçkapılı granodiorite (Paleozoic to Mesozoic), Kızılkaya Ignimbrite (Upper Miocene to Pliocene), Karataş Volcanites (Middle Pleistocene), Quaternary fluvial sediments, talus and alluvium. The tectonics, basin development, volcanism and geomorphology of the Central Anatolia are largely under the control of three dominant faults. These are the NW-SE trending and strike slip Tuzgölü Fault, NNE to SSW trending and left lateral strike-slip Ecemiş Fault and NE to SW trending dip slip Niğde Fault. In order to obtain concrete geological information related to this fault, electric resistivity and self-potential (SP) measurements made 50 m interval on two profile, which was out the fault line vertically. SP and Electrical resistivity measurements made in 76 points along the first profile, 49 points along the second profile where located at SW and NE of the Niğde, separately. High Electrical resistivity and SP values were recorded at 10, 40, 45 points in the first profile and 11, 27 and 47 points in the second profile. These points are evaluated as an important finding of the existence of discontinuities of the Niğde Fault Zone, which is covered by young sediments. It is understood from the Electrical resistivity and SP data that the Niğde Fault Zone consisting of at least three segments (S1, S2, S3). The distance from the segment (S1), which is located in the South, to the NW margin of the Nigde Massif varies from 750 to 2500 m. These segments are parallel to each other extend in NE-SW direction. The NW edge of the massif is the fault scarp, which was retrograde towards to SE direction, in the Middle Miocene-Early Pliocene time. The presence of thick talus on the NW side of this fault zone supports this idea. © SGEM2017. All Rights Reserved.
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    Optimization of elastic spring supports for cantilever beams
    (Springer, 2020) Aydin, Ersin; Dutkiewicz, Maciej; Ozturk, Baki; Sonmez, Mustafa
    In this study,a new approach of optimization algorithm is developed. The optimum distribution of elastic springs on which a cantilever Timoshenko beam is seated and minimization of the shear force on the support of the beam is investigated.The Fourier transform is applied to the beam vibration equation in the time domain and transfer function, independent from the external influence, is used to define the structural response. For all translational modes of the beam, the optimum locations and amounts of the springs are investigated so that the transfer function amplitude of the support shear force is minimized. The stiffness coefficients of the springs placed on the nodes of the beam divided into finite elements are considered as design variables. There is an active constraint on the sum of the spring coefficients taken as design variables and passive constraints on each of them as the upper and lower bounds. Optimality criteria are derived using the Lagrange Multipliers method. The gradient information required for solving the optimization problem is analytically derived. Verification of the new approach optimization algorithm was carried out by comparing the results presented in this paper with those ones from analysis of the model of the beam without springs, with springs with uniform stiffness and with optimal distribution of springs which support a cantilever beam to minimize the tip deflection of the beam found in the literature. The numerical results show that the presented method is effective in finding the optimum spring stiffness coefficients and location of springs for all translational modes.The proposed method can give designers an idea of how to support the cantilever beams under different harmonic vibrations.
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    Quaternary bimodal volcanism in the Nigde Volcanic Complex (Cappadocia, central Anatolia, Turkey): age, petrogenesis and geodynamic implications
    (SPRINGER, 2014) Aydin, Faruk; Schmitt, Axel K.; Siebel, Wolfgang; Sonmez, Mustafa; Ersoy, Yalcin; Lermi, Abdurrahman; Duncan, Robert
    The late Neogene to Quaternary Cappadocian Volcanic Province (CVP) in central Anatolia is one of the most impressive volcanic fields of Turkey because of its extent and spectacular erosionally sculptured landscape. The late Neogene evolution of the CVP started with the eruption of extensive andesitic-dacitic lavas and ignimbrites with minor basaltic lavas. This stage was followed by Quaternary bimodal volcanism. Here, we present geochemical, isotopic (Sr-Nd-Pb and delta O-18 isotopes) and geochronological (U-Pb zircon and Ar-Ar amphibole and whole-rock ages) data for bimodal volcanic rocks of the Ni g de Volcanic Complex (NVC) in the western part of the CVP to determine mantle melting dynamics and magmatic processes within the overlying continental crust during the Quaternary. Geochronological data suggest that the bimodal volcanic activity in the study area occurred between ca. 1.1 and ca. 0.2 Ma (Pleistocene) and comprises (1) mafic lavas consisting of basalts, trachybasalts, basaltic andesites and scoria lapilli fallout deposits with mainly basaltic composition, (2) felsic lavas consisting of mostly rhyolites and pumice lapilli fall-out and surge deposits with dacitic to rhyolitic composition. The most mafic sample is basalt from a monogenetic cone, which is characterized by Sr-87/Sr-86 = 0.7038, Nd-143/Nd-144 = 0.5128, Pb-206/Pb-204 = 18.80, Pb-207/Pb-204 = 15.60 and Pb-208/Pb-204 = 38.68, suggesting a moderately depleted signature of the mantle source. Felsic volcanic rocks define a narrow range of Nd-143/Nd-144 isotope ratios (0.5126-0.5128) and are homogeneous in Pb isotope composition (Pb-206/Pb-204 = 18.84-18.87, Pb-207/Pb-204 = 15.64-15.67 and Pb-208/Pb-204 = 38.93-38.99). Sr-87/Sr-86 isotopic compositions of mafic (0.7038-0.7053) and felsic (0.7040-0.7052) samples are similar, reflecting a common mantle source. The felsic rocks have relatively low zircon delta O-18 values (5.6 +/- 0.6 %) overlapping mantle values (5.3 +/- 0.3 %), consistent with an origin by fractional crystallization from a mafic melt with very minor continental crustal contamination. The geochronological and geochemical data suggest that mafic and felsic volcanic rocks of the NVC are genetically closely related to each other. Mafic rocks show a positive trend between Sr-87/Sr-86 and Th, suggesting simultaneous assimilation and fractional crystallization, whereas the felsic rocks are characterized by a flat or slightly negative variation. High Sr-87/Sr-86 gneisses are a potential crustal contaminant of the mafic magmas, but the comparatively low and invariant Sr-87/Sr-86 in the felsic volcanics suggests that these evolved dominantly by fractional crystallization. Mantle-derived basaltic melts, which experienced low degree of crustal assimilation, are proposed to be the parent melt of the felsic volcanics. Geochronological and geochemical results combined with regional geological and geophysical data suggest that bimodal volcanism of the NVC and the CVP, in general, developed in a post-collisional extensional tectonic regime that is caused by ascending asthenosphere, which played a key role during magma genesis.
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    Slab break-off-related magnesian andesites and dacites with adakitic affinity from the early Quaternary Keciboyduran stratovolcano, Cappadocia province, central Turkey: evidence for slab/sediment melt-mantle interaction and magma mixing
    (Springer, 2022) Aydin, Faruk; Sonmez, Mustafa; Siebel, Wolfgang; Karsli, Orhan; Lermi, Abdurrahman
    Voluminous moderate- to high-magnesian [Mg# = molar Mg/(Mg- + Fe2+) = 44-64] andesitic and dacitic rocks with high silica (mostly 61-66 wt%) adakitic affinity (Y = 13-22, Yb = 1.3-2.1, Sr/Y = 18-44, La/Yb = 10-25) and common mafic magmatic enclaves (MMEs) are first reported in the Keciboyduran stratovolcano (KSV) from the Cappadocia volcanic province (CVP), Central Anatolia, Turkey. We present comprehensive whole-rock geochemistry and Sr-Nd-Pb isotope data, mineral chemical compositions and 40Ar-39Ar ages for KSV samples. Based on the volcanostratigraphy and 40Ar-39Ar dating results, two successive eruption ages of 2.2-1.6 Ma (stage I: amphibole-rich) and 1.6-1.2 Ma (stage II: pyroxene-rich) were established for the KSV, corresponding to the Gelasian and Calabrian stages of Early Pleistocene, respectively. Textural and geochemical evidence indicates that the KSV magnesian andesites-dacites are products of a hybrid magma formed by mixing between mantle-derived mafic and crust-derived felsic magmas with further fractionation and minor contamination during magma storage and ascent. Our new data, combined with previous geological and geophysical results suggest that parental magnesian mafic melts of the KSV rocks originated from a heterogenous mantle source generated through the metasomatism of mantle wedge material by subducted sediment-derived melts, and then partially melted through asthenospheric upwelling in response to slab break-off. The mafic magma underplated the overlying lower crust, resulting in its partial melting to generate crustal felsic magma. Both magmas mixed at lower crustal levels creating MME-rich hybrid magmas. Subsequently, the hybrid magmas were emplaced at different depths of the crust (c. 4-11 and 11-15 km for the stage I and II, respectively), where they crystallized at moderate temperatures (c. 1180-840 degrees C) and under relatively high oxygen fugacity (LogfO(2) = - 11.4 to - 9.2), water-rich (H2Omelt = 5.6-3.6 wt%) and polybaric (similar to 1.2 to 5.1 kbars) conditions, and underwent fractionation of primarily amphibole +/- pyroxene causing adakitic affinity. We propose a new petrogenetic model for the early Quaternary magnesian/adakitic andesites/dacites of the CVP in a post-subduction tectonic setting. Our results provide robust evidence for slab break-off of the eastern Cyprus oceanic lithosphere and put further constraints on the tectonic evolution of the eastern Mediterranean collision zone during the Early Quaternary.