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Öğe Adsorption characteristics of heavy metals in soil zones developed on spilite(SPRINGER, 2006) Gurel, AliVarious soil zones such as Bw, C1, and C3 are developed on spilite. Montmorillonite, vermiculite and chlorite is moderately occurred in the C1 and C3 soil zones, in contrast montmorillonite and vermiculite are absent in Bw soils whereas illite and sesquioxide are relatively increased. The high cation exchange capacity (CEC) of montmorillonite and vermiculte and moderate CEC of chlorite and illite resulted in the high adsorption of heavy metals. The adsorption of the heavy metals on spilite soil zones was studied at different concentrations and pH levels. Heavy metals like lead, cadmium, and copper were selected for adsorption studies considering their contribution as toxic metals in the environment. The initial solute concentrations ranged from 7.0 x 10(-3) to 1.0 X 10(2) mg/L. The sorption behavior of Cd2+, Pb2+, and Cu2+ on soil zones of spilite was investigated using the batch equilibrium technique at 25 degrees C. The characteristics of the adsorption process were investigated using Scatchard plot analysis (q/C vs. q) by the batch equilibrium technique at 25 degrees C. In the adsorption of heavy metals, deviation from linearity in the plot of q/C versus q was observed, indicating the presence of multi-model interaction and non-Langmuirean behavior. When the Scatchard plot showed a deviation from linearity, greater emphasis was placed on the analysis of the adsorption data in terms of the Freundlich model, in order to construct the adsorption isotherms of the metal(s) at particular concentration(s) in solutions. The adsorption behavior of these metal ions on spilite soil zones is expressed by the Freundlich isotherms. Adsorption constants and correlation coefficients for the Cd, Pb, and Cu on spilite soil zones were calculated from Freundlich plots.Öğe Ar-40/Ar-39 dating of ignimbrites and plinian air-fall layers from Cappadocia, Central Turkey: Implications to chronostratigraphic and Eastern Mediterranean palaeoenvironmental record(ELSEVIER GMBH, 2014) Lepetit, Petra; Viereck, Lothar; Piper, John D. A.; Sudo, Masafumi; Gurel, Ali; Copuroglu, Ibrahim; Gursoy, HalilMagmatism forming the Central Anatolian Volcanic Province of Cappadocia, central Turkey, records the last phase of Neotethyan subduction after similar to 11 Ma. Thirteen large calc-alkaline ignimbrite sheets form marker bands within the volcano-sedimentary succession (the Urgup Formation) and provide a robust chronostratigraphy for paleoecologic evaluation of the interleaved paleosols. This paper evaluates the chronologic record in the context of the radiometric, magnetostratigraphic and lithostratigraphic controls. Previous inconsistencies relating primarily to K/Ar evidence were reason for the initiation of an integrated study which includes Ar-40/Ar-39 dating, palaeomagnetic and stratigraphic evidence. The newly determined Ar-40/Ar-39-ages (Lepetit, 2010) are in agreement with Ar/Ar and U/Pb data meanwhile published by Pauquette and Le Pennec (2012) and Aydar et al. (2012). The Ar-40/Ar-39-ages restrict the end of the Urgup Formation to the late Miocene. The paleosol sequence enclosed by the ignimbrites is thus restricted to the late Miocene, the most intense formation of pedogene calcretes correlating with the Messinian Salinity Crisis. (C) 2014 Elsevier GmbH. All rights reserved.Öğe COMPETITIVE SORPTION CHARACTERISTICS OF HEAVY METAL IONS ON HUMUS-SOIL ZONES DEVOLOPED ON MUDSTONE AND SPILITE (HARZ FOREST, GERMANY)(STEF92 TECHNOLOGY LTD, 2015) Gurel, Ali; Ayar, AhmetIn order to evaluate the sorption behavior of Cd2+, Pb2+, and Cu2+ ions on humus rich O and E/EB soil zones of mudstone and spilite, batch equilibrium experiments were performed at 25 degrees C in competitive component adsorption systems. Heavy metal ions like Cd2+, Pb2+, and Cu2+ were selected for adsorption studies considering their contribution as toxic metals in the environment. The adsorption of the heavy metal ions was studied at different initial solute concentrations and pH levels. The initial metal concentrations ranged from 7.0 10(-3) to 1.0 10(2) mg/L. The adsorption isotherms were obtained and firstly, Scatchard plot analysis (q/C vs. q) was used to investigate the adsorption behavior of the metal ions. However, in the adsorption of metal ions, deviation from linearity in the plot of q/C versus q was observed, indicating the presence of multi-model interaction and non-Langmuirean behavior. The adsorption behavior of these metal ions on soil zones of spilite and mudstone was expressed by the Freundlich isotherms. Adsorption constants and correlation coefficients were calculated from Freundlich plots.Öğe COMPETITIVE SORPTION CHARACTERISTICS OF LEAD-, COPPER-AND CADMIUM-IONS ON FOREST SOIL HORIZONS DEVELOPED ON MUDSTONE, SOSE DAM, GERMANY(Parlar Scientific Publications (P S P), 2018) Gurel, AliThe sorption of the heavy metal ions was studied using their solutions with different concentrations and pH values. Scatchard plot analysis was used to investigate the sorption behavior of the metal Pb2+, Cu2+, and Cd2+ ions. The sorption behavior of these ions on sesquioxide and clay minerals with Bw, BC and Bw soil horizons of mudstone obtained from Harz forest drainage basin of Sose Dam (Germany) was studied. Batch equilibrium experiments were performed at 25 degrees C in competitive component sorption systems. A deviation from linearity in the Scatchard plot revealing the presence of multi-model interaction and non-Langmuirean behavior were observed. The sorption behavior of these metal ions was stated by using Freundlich isotherms. Sorption constants and correlation coefficients were calculated from Freundlich plots. In general, the Freundlich model has been adapted very well for the use of the sorption data of metals on the soils obtained from investigated horizons. The results showed that Pb is adsorbed strongly by these forest soil horizons compared to Cu and Cd in triple metal system. It was found that BC-soil horizon at high pH, sesquioxide, and clay content showed the greatest sorption capacity. The coexistence of Pb as a third metal with Cd and Cu has reduced their sorption. In addition, the sorption of Cd and Cu in soil decreases when the pH falls to 3.5 and increases when pH rises up to 6.Öğe Diatom communities, lithofacies characteristics and paleo environmental interpretation of Pliocene diatomite deposits in the lhlara-Selime plain (Aksaray, Central Anatolia, Turkey)(PERGAMON-ELSEVIER SCIENCE LTD, 2007) Gurel, Ali; Yildiz, AysegulThe present investigation uses palaeontological, sedimentological, mineralogical and chemical analyses of diatom-bearing lacustrine deposits to determine the palaeoenvironmental history of the Pliocene-age of the Ihlara-Selime plain in the western part of the Cappadocia Volcanic Province. The diatomite is composed of amorphous silica, opal, cristobalite, quartz, feldspar and montmorillonite. Chemical analyses show that diatomite is comprised of SiO2 85.05%, Al2O3 5.30%, Fe2O3 1.22%, CaO 0.12%, MgO 0.58%, Na2O 1.52% and K2O 0.22%. The high SiO2 content of Ihlara-Selime plain diatomite is highly conspicuous, as it could be predicted. Six horizons comprised of diatomite, palaeosols, limestone, massive conglomerate, massive calcrete, and trough-cross bedded sandstone describe the associated lithofacies (A-F). Twenty-five species were identified belonging to 20 diatom genera, from the analysis of 24 samples from three excavated sections of diatomite. The fossil diatom assemblages are mainly comprised of freshwater, epipelic, mesotrophic, mesosaprophic and alkaline forms. The flora is dominated by benthic species with very low abundance of planktonic species, indicating that the diatomite of the area under study was deposited in a shallow, silicate rich, alkaline and mesotrophic freshwater lake. Water levels, nutrient content, water temperature and alkalinity fluctuated through time. In addition, there was a difference between section one, and sections two and three locations in terms of the deposition conditions. (c) 2006 Elsevier Ltd. All rights reserved.Öğe Diatom community and palaeoenvironmental properties of Karacaoren diatomite deposits (Nevsehir, Central Anatolia, Turkey)(Pergamon-Elsevier Science Ltd, 2017) Yildiz, Aysegul; Gurel, Ali; Dursun, Yusuf GokhanThe diatom community and palaeoenvironmental properties of volcano genetic diatomite deposits that outcrop in the Karacabren (Nevehir) area are described. Two stratigraphic sections were measured in the study area. One of these sections was measured in Quaternary lake units (K1), and the other in lacustrine sediments of the late Miocene -Pliocene Urgup Formation's Bayramhaoh Member (K2). According to stratigraphic and chemical characteristics of the sections, two distinct paleogeographic domains were determined in the study area. One of these, the shallow lacustrine to fluvial area (Quaternary) which is represented by an alternating sequence of diatomite, silt/mud, and tuffite. The other was the deeper lacustrine stage (late Miocene) which is represented by diatomites with some interbedded mud fades, chert and volcanics. From the diatomite samples of these sections, twenty-five species of 10 different diatom genera were identified. When evaluated together, the ecological properties and the distribution of numerical values of the determined diatom genera and species, showed that the study area's diatomite was generally deposited in shallow, high temperature, nutrient-rich water, where nitrogen and phosphorus were abundant and which was an alkaline (pH > 7) freshwater lake environment. Over time the pH value of the environment decreased (pH < 7), and the environment became acidic. (C) 2017 Elsevier Ltd. All rights reserved.Öğe Geology of Late Miocene clayey sediments and distribution of palaeosol clay minerals in the north-eastern part of the Cappadocian Volcanic Province (Arapli-Erdemli), central Anatolia, Turkey(SCIENTIFIC TECHNICAL RESEARCH COUNCIL TURKEY-TUBITAK, 2013) Kadir, Selahattin; Gurel, Ali; Senem, Hulya; Kulah, TacitThe study area is situated in the Arapli-Erdemli (Kayseri) area in the north-eastern part of the Cappadocian Volcanic Province (CVP), central Anatolia. The Late Miocene series comprises lacustrine and fluvial deposits interbedded with ignimbrites and lava flows. The Late Miocene Mustafapasa member of the Urgup Formation comprises yellow to red mudstone that alternates with thin sandstone beds in the north-eastern part of the CVP. This unit continues upward through the Cemilkoy ignimbrite palaeosol layers (comprising altered Cemilkoy ignimbrite, vertisol and well-developed palaeosol layers), the Gordeles ignimbrite and red palaeosol layers, and includes two fallout levels; it is overlain by the Kizilkaya ignimbrite. The Mustafapasa member is dominated by smectite +/- illite +/- chlorite, whereas the altered Cemilkoy ignimbrite is predominantly kaolinite +/- smectite +/- chlorite. The underlying lower level of the Gordeles ignimbrite contains palaeosol layers, and continues upward through smectite-dominated layers. Alteration of feldspars and glass shards in the Cemilkoy and Gordeles ignimbrites resulted in the depletion of soluble alkaline elements (such as Ca, Na and K) from these ignimbrites downward to the Mustafapasa member, and palaeosol levels (Bayramhacili member) in the Arapli area favoured precipitation of smectite in an alkaline environment. However, the absence of these elements in these ignimbrites may have resulted in the enhancement of Al+Fe/Si-favoured precipitation of kaolinite in an acidic environment. Conversely, palaeosol of the Erdemli area consists of smectite +/- illite +/- chlorite. Micromorphologically, flaky smectite rims illite in both the Arapli and Erdemli areas and this can be explained by the release of K and Al during desorption of feldspar. Additionally, higher Ni, Co and Cr2O3 values in the mudstone samples of the Mustafapasa member and palaeosol levels, the presence of iron oxide and partially chloritised pyroxene and hornblende, together with ophiolitic and metamorphic grains, indicate that the basin also accumulated ophiolitic and metamorphic rock fragments in its sediment supply. This suggests that the Arapli area in the southern part of the CVP has undergone erosion, and that the present-day Erdemli area was close to the shallow-lake depositional environment of the northern part of CVP.Öğe Geology, mineralogy and geochemistry of Pleistocene-Holocene deposits in the Ciftlik Basin (Nigde) (Central Turkey)(E SCHWEIZERBARTSCHE VERLAGSBUCHHANDLUNG, 2016) Gurel, AliThe Quaternary basin fills of the Ciftlik (Central Anatolia, Turkey), comprised of partially lithified sediments, and was studied from drill cores to reconstruct the paleoenvironment of deposition as well as the timing of sediment accumulation. Six lithofacies were identified as (A) clast-supported gravel, (B) horizontally-bedded sand, (C) alternating silt-mud, (D) diatomite, (E) disrupted mud, (F) and tuff. The siliciclastic and diatomite facies were interpreted as fluvial-lacustrine deposits associated with a volcanic area (tuff) while the disrupted mud were identified as two types of paleosols: Inceptisols and Andisols. These paleosols are mainly composed of opal A, opal CT, quartz, feldspar, and clay minerals such as smectite, illite, and chlorite. The diatomite is mainly composed of opal A, opal CT, quartz, feldspar and clay minerals such as smectite. Weathering of the tuff resulted in consumption of SiO2, Al2O3+ Fe2O3, TiO2 and K2O by precipitation of smectite +/- illite in paleosols. SiO2 was enriched in the lake water for the accumulation of diatomite. The fossil diatom assemblages were mainly comprised of benthic, cosmopolitan, eutrophic, alkalibiontic, and mesosaprophic forms, living in a lake with open drainage, shallow depth, nutrient-rich waters, and high alkalinity. However, water level, salinity, alkalinity, and permanent of the lake level changed during the deposition of the diatomite.Öğe Geology, mineralogy and origin of clay minerals of the Pliocene fluvial-lacustrine deposits in the Cappadocian volcanic province, central Anatolia, Turkey(CLAY MINERALS SOC, 2006) Gurel, Ali; Kadir, SelahattinThe Guzeloz-Incesu Plateaus are situated in the central and eastern parts of the Cappadocian volcanic province (central Anatolia). This province contains many ignimbrite levels, andesite, basalt intercalated with several paleosols, calcrete, carbonate, fluvial sediments, diatomaceous clayey sediments and pyroclastic sedimentary levels. The presence of mottling, sesquioxide, root traces, rhizoids and burrows in continuous, finely bedded and laminated sediments, paleosols, calcrete, the occurrence of bone- and teeth-bearing reworked pyroclastic materials, and the description of the lithofacies in the study area indicate fluvial and shallow-lake environments. These environments are dominated by smectite and illite, with traces of kaolinite, associated mainly with plagioclase, K-feldspar, quartz, calcite, opal-CT, pyroxene (diopside, rare hypersthene), and locally trace amounts of gypsum and sepiolite. Smectite predominates in paleosols and calcrete units, and generally increases upwards in the profiles, coinciding with a gradual increase in the degree of alteration. Partial to complete alteration of plagioclase, K-feldspar, pyroxene and partial devitrification of glass-shard particles in pyroclastic rocks, development of microsparitic to sparitic cement comprising euhedral rhombic calcite crystals between irregular clay nodules in paleosol and calcrete samples, along with the occurrence of dogtooth-type sparitic crystals in fractures, desiccation cracks and geopetal-type fenestrae, indicate alternating periods of drought and wet, resulting in the development of paleosols and calcretes. Micromorphological development of spongiform smectite on mainly relict feldspar and, locally, on glass shards, indicates an authigenic origin, whereas illite formed either authigenically or by conversion of smectite to illite-smectite.Öğe Geology, mineralogy, and geochemistry of late Miocene paleosol and calcrete in the western part of the Central Anatolian Volcanic Province (CAVP), Turkey(Elsevier, 2017) Gurel, AliThe late Miocene was characterized by high global temperatures and partly to nearly complete desiccation of the Mediterranean Sea throughout the latter part of the Messinian age (the Messinian salinity crisis). The non-marine paleoenvironmental and paleoclimatic records from the Mediterranean area are highly limited in their spatial range. Late Miocene river flood-plain sediments in the Central Anatolian Volcanic Province (CAVP) of central Turkey consist of siliciclastic and pyroclastic sediments with paleosols and calcrete. Five lithofacies were identified as (A) massive conglomerate, (B) trough-cross-bedded sandstone, (C) massive mudstone, (D) disrupted mud, (E) and disrupted matrix-supported conglomerate. The paleosols were composed predominantly of smectite and illite with smaller amounts of feldspar, quartz, opal-A, pyroxene and amphibole, and the calcretes were composed mainly of calcite, with smaller amounts of feldspar, quartz and opal-A, and minor amounts of smectite, chlorite and illite. Authigenic clay minerals and micritic calcite coating on the detrital grains and soil peds and pendant cement in the calcrete and paleosol horizons were evidence of a vadose zone. In contrast, the large equant spar drusy mosaics were formed in phreatic environments. The weathering of ignimbrite and marble led to the depletion of SiO2, CaO, Al2O3, Fe2O3, TiO2, and K2O through the precipitation of smectite and illite in the paleosols, and CaO in the form of micrite and calcite in the calcrete horizons. Field observations, mineralogy, geochemistry and the results of delta O-18 and delta C-13 isotopic analysis reveal that alternating wet and dry periods resulted in an upward increase in precipitation of authigenic smectite and illite within the late Miocene sections, under the influence of geochemical and pH fluctuations in phreatic or vadose water within the river flood-plain paleoenvironment.Öğe Geology, mineralogy, geochemistry, and depositional environment of a Late Miocene/Pliocene fluviolacustrine succession, Cappadocian Volcanic Province, central Anatolia, Turkey(SCIENTIFIC TECHNICAL RESEARCH COUNCIL TURKEY-TUBITAK, 2014) Goz, Ersel; Kadir, Selahattin; Gurel, Ali; Eren, MuhsinThis paper investigates the mineralogy, geochemistry, and depositional environment of Late Miocene/Pliocene fluviolacustrine deposits, including multiple ignimbrite levels and andesitic and basaltic lavas, within the Cappadocian Volcanic Province (CVP) of central Anatolia, Turkey. Palaeosols and calcretes formed within these terrestrial sedimentary rocks under near-surface or surface conditions. The palaeosols are composed predominantly of smectite +/- illite with feldspar, quartz, calcite, opal-CT, and amphibole, and the calcretes mainly of calcite with minor feldspar, quartz, and accessory smectite +/- palygorskite. The palygorskite occurs on and between the calcite crystals in the calcretes and at the edges of smectite flakes within the palaeosols, indicating an in situ formation from evaporated alkaline water rich in Si and Mg and poor in Al under arid or seasonally arid climatic conditions. In the palaeosols and calcretes, negative Ba, Nb, Ce, Sr, and Ti anomalies and an enrichment of light rare earth elements relative to medium rare earth elements and heavy rare earth elements, with a distinct negative Eu anomaly, likely reflect the alteration of feldspars and amphiboles in the ignimbrite. The alteration of the ignimbrites caused the depletion of SiO2, Al2O3+Fe2O3, TiO2, and K2O through the precipitation of smectite +/- illite in the palaeosols and CaO in the form of calcite in the calcretes. The delta O-18 values of the calcretes and limestones range from -8.71% to -10.71%, which are mainly related to the involvement of high-elevation meteoric water, whereas the delta C-13 values for the same rocks vary between -1.97% and 5.71%. The positive delta C-13 values for the limestones reflect calcite precipitation in isotopic equilibrium with meteoric water in a lake. The slightly negative delta C-13 values of the lacustrine limestone carbonates may indicate precipitation from a relatively thick water column and an inflow of surface or groundwater through the ignimbrites with high Ba/Sr values. Conversely, the calcrete delta C-13 values (3.0% to 4.97%) may suggest a pedogenic origin with low plant respiration rates and a predominance of C-4 plants. Based on stable oxygen isotope values from the lake sediments and calcretes, this study suggests that the global warming trend that followed the Late Miocene continued into the Pliocene within the CVP.Öğe Investigation of the Geological, Mineralogical, and Geochemical Contents of the Sedimentary Fills in the Northern Area of the Quaternary-Aged Bor Basin (Niğde/Turkey): Implications for Sediment Source and Paleoclimates(Mdpi, 2024) Sahinoglu, Alperen; Gurel, AliIn the northern part of the Ni & gbreve;de (Central Anatolian) Quaternary Bor Basin, stratigraphic sections P1 and P2 were sampled, reaching depths of 11 m and 25 m. The samples were analyzed with thin-section, XRD, and chemical analyses (ICP-MS) to determine their chemical and mineralogical properties. In the study area, partially lithified volcano-sedimentary rocks comprised paleosol, calcrete, gravel, sand, silt, mud, clay, and volcanoclastics such as pumice fall-out. Grain size analyses from the Zengen (P1) and Altunhisar (P2) regions showed very poor sorting and strong positive skewness. The Zengen-area (P1) samples contained rock fragments, calcite, quartz, opal-CT, feldspar, amphibole, pyroxene, biotite, and clay minerals such as smectite, chlorite, illite, palygorskite, and sepiolite. In calcrete zones, however, the amounts of CaO increased, whereas significant decreases in the amounts of SiO2 were observed. Therefore, a negative correlation between SiO2 and CaO was observed. The vertical distributions and behaviors of trace elements in the Zengen-area profile showed variation with the different levels of the P1 section. It is thought that in the Bor Plain, after 17,000 years ago, no lacustrine phase reached a level above the periglacial lake level in the region, reaching this level with the melting of the ice sheets in the area. During the late glacial period, shallow freshwater lacustrine phases and paleosols were identified from 12,500 to 11,000 yr BP in the basin.Öğe Mineralogical and chemical changes in parent rocks and in soil ecosystems (Mazmili Da?I, Adana, Turkey)(2007) Gurel, Ali; Kerey, Erdal; Lermi, AbdurrahmanIn this study, the region of Alada?lar-Mazmi{dotless}li{dotless} (Adana) has been selected as research area and covering on area of 95 square kilometers. A number of anatical methods including Attarberg, XRD, XRF and ICP have been employed to characterize representative samples collected from the soils developed partially weathered country rocks with respect to their chemical and mineralogical contents. Soil horizons did not well developed on the limesstone and ultramafic parent roks that include mainly harzburgite-dunite, ophyolite melange due to rapid weatering and steep topography. However, soil zones well-developed, forming terra-rosa over ohiolite melange and its debris. Clay species belonging to smectite, kaolinite, and mixed-layer groupes have been formed during pedogenesis. Clay contents and abundances vary depending on the morphology. Although the limestone and harzburgite - dunite dont contain quartz, the soils developed on them comprised significant amounts of quartz. Mazmi{dotless}li{dotless} area soils did not develop homogeneausly, they are rather inhomogeneous. MgO and CaO contents show depletion upward, whereas, the other major element oxides including, as Al2O3, Fe2O3, SiO2 and MnO increase. These soils are slightly basic and enriched in K2O, and Na2O. Heavy immobile elements such as Zr and Ti show strongly parent rock-controled distributions. A total of three soil profile has been investigated in this research. Chemical analysis indicated that the major and trace element chemistry of all three show good agreement with the world soil standards. Only difference noticed was anomalous chromium and nickel values due to the host rock chemistry.Öğe MINERALOGICAL AND GEOCHEMICAL CHARACTERISTICS AND GENESIS OF THE GUZELYURT ALUNITE-BEARING KAOLINITE DEPOSIT WITHIN THE LATE MIOCENE GORDELES IGNIMBRITE, CENTRAL ANATOLIA, TURKEY(CLAY MINERALS SOC, 2014) Kadir, Selahattin; Kulah, Tacit; Eren, Muhsin; Onalgil, Nergis; Gurel, AliThe Guzelyurt kaolinite deposit is an important source of raw material for the ceramics industry in Turkey. No detailed mineralogical or geochemical characterizations of this deposit have been undertaken previously and these were the goals of the present study. The Guzelyurt alunite-bearing kaolinite occurs along a fault zone in the Late Miocene Gordeles ignimbrite, which consists of dacitic and andesitic tuffs. Horizontal and vertical mineralogical zonations. with gradual transitions were observed within the alteration zone. The inner kaolinite, alunite, and 7 angstrom halloysite zones progress horizontally outward to a smectite zone; and native sulfur- and cinnabar-bearing alunite with 7 angstrom halloysite and porous silica zones increase as one progresses up through the profile. Fe-(oxyhydr)oxide phases associated with native sulfur and cinnabar demonstrate that multiple hydrothermal-alteration processes resulted in kaolinization and alunitization of the deposit. The kaolinization of feldspar, Fe-(oxyhydr)oxidation of hornblende and mica, the presence of kaolinite as stacked and, locally, book-like forms, and of 7 angstrom halloysite tubes, and smectite flakes as a blanket on altered volcanic relicts indicate an authigenic origin for this deposit. The leaching of Si + Mg + K and Ba + Rb, the retention of Sr, the enrichment of light rare earth elements relative to the heavy rare earth elements, and the negative Eu anomalies suggest that fractionation of plagioclase and hornblende occurred within the volcanics. The oxygen- and hydrogen-isotopic values of the kaolinite, 7 angstrom halloysite, smectite, and smectite + kaolinite fractions reflect a steam-heated environment at temperatures in excess of 100 degrees C. An increase in the delta O-18 and 5180 values of 7 angstrom halloysite relative to kaolinite suggests its formation under steam-heated magmatic water, the mixing of steam and meteoric water near the surface, and evaporation. The oxygen- and sulfur-isotopic compositions of alunite suggest the direct influence of steam-derived sulfur. The Guzelyurt alunite-bearing kaolinite deposit is inferred to have formed after an increase in the (Al +/- Fe)/Si ratio and the leaching of alkali elements, which are driven by the sulfur-bearing low-temperature hydrothermal alteration of feldspar, hornblende, and volcanic glass under acidic conditions within the Neogene dacitic and andesitic tuffs.Öğe MINERALOGICAL, GEOCHEMICAL AND GENETIC IMPLICATION OF SMECTITE AND SEPIOLITE IN THE OLIGO/MIOCENE LACUSTRINE CLAYEY SEDIMENTS OF THE KURTULMUSTEPE FORMATION, AKTOPRAK BASIN, NIGDE, CENTRAL ANATOLIA, TURKEY(STEF92 TECHNOLOGY LTD, 2013) Gurel, AliAktoprak Basin is situated among the Melendiz Mountains in the north, middle Taurus range in the south, Tuz Golu and Konya plain in the west and Nigde Crystalline Massif in the east. The Oligo/Miocene Kurtulmustepe Formation represents fluvial and shallow lake sediments of the Aktoprak Basin. This unit consists of thin bedded white marl, alternating with massif of white limestone, and red colored mudstone overlies Zeyvegedigi anhidriti, south of Ulukisla/Nigde. Further south in the area between Aktoprak and Yeniyildiz villages, this formation overlies ophiolitic basement rocks (Late Cretaceous) and this area consists of marl, limestone, and sandstone and mudstone alternation. These units were examined using polarised-light microscopy, X-ray diffractometry, scanning electron microscopy and energy dispersive analyses (SEM-EDX), and chemical analyses. Mineralogical distribution in these units south to north is as follow: (1) Quartz + calcite + feldspar and amphibole; relative abundance of clay minerals are, smectite + sepiolite (2) Calcite + feldspar + quartz and amphibole; relative abundance of clay minerals are, smectite + sepiolite While smectite is abundant clay mineral in southern part of the basin, sepiolite amount relatively increases to the northward in mudstone deposits of the Kurtulmustepe Formation. Marl units exhibit micritic texture, sepiolite dominated by microsparitic calcite crystals in desiccation cracks and pores, also bear vadose cements and organic matter (a rich assemblage of gastropods, ostracodes, plant spoors and algae and bivalve's fragments). Observations via scanning electron microscopy indicate formation of sepiolite as bridges between calcite crystal, edging smectite plates and fiber-bundle. Marl samples are characterized by high CaO and loss on ignition values, and host-rock mudstone samples consist mainly of SiO2, Al2O3+Fe2O3+MgO, LOI and relatively high CaO value, revealing the presence of smectite and sepiolite associated with feldspar, quartz and calcite. Barium and Rb are relatively high and constant in the mudstone, compared to the marl. Positive correlation between 1(20 and Rb+Ba in mudstone and marl samples as a function of the presence of K-bearing minerals, such as feldspar. Based on field evidence, mineralogical and geochemical determinations, the sepiolite is presumed to have formed authigenically either by coprecipate with calcite during calcification or by conversion from detrital smectite or direct precipitation under super saturation condition. Thus, sepiolite precipitated in a vadose zone from strongly evaporatived alkaline water rich in Si and Mg and low in Al at increased temperatures and advanced stage of marl formation. The Si, Mg, Al+Fe and Ca required for sepiolite formation and calcification were supplied in solution from the smectitic clays, ophiolitic units and related volcanic units and carbonates in the close area.Öğe Mineralogical, Geochemical and Genetic Implication of Smectite and Sepiolite in the Oligo/Miocene Lacustrine Clayey Sediments of the Kurtulmuştepe Formation, Aktoprak Basin, Nigde, Central Anatolia, Turkey(2013) Gurel, AliAktoprak Basin is situated among the Melendiz Mountains in the north, middle Taurus range in the south, Tuz Gölü and Konya plain in the west and Ni?de Crystalline Massif in the east. The Oligo/Miocene Kurtulmuştepe Formation represents fluvial and shallow lake sediments of the Aktoprak Basin. This unit consists of thin bedded white marl, alternating with massif of white limestone, and red colored mudstone overlies Zeyvegedi?i anhidriti, south of Uluki{dotless}şla/Nigde. Further south in the area between Aktoprak and Yeniyi{dotless}ldi{dotless}z villages, this formation overlies ophiolitic basement rocks (Late Cretaceous) and this area consists of marl, limestone, and sandstone and mudstone alternation. These units were examined using polarised-light microscopy, X-ray diffractometry, scanning electron microscopy and energy dispersive analyses (SEMEDX), and chemical analyses. Mineralogical distribution in these units south to north is as follow: (1) Quartz + calcite + feldspar and amphibole; relative abundance of clay minerals are, smectite + sepiolite (2) Calcite + feldspar + quartz and amphibole; relative abundance of clay minerals are, smectite + sepiolite While smectite is abundant clay mineral in southern part of the basin, sepiolite amount relatively increases to the northward in mudstone deposits of the Kurtulmuştepe Formation. Marl units exhibit micritic texture, sepiolite dominated by microsparitic calcite crystals in desiccation cracks and pores, also bear vadose cements and organic matter (a rich assemblage of gastropods, ostracodes, plant spoors and algae and bivalve's fragments). Observations via scanning electron microscopy indicate formation of sepiolite as bridges between calcite crystal, edging smectite plates and fiber-bundle. Marl samples are characterized by high CaO and loss on ignition values, and host-rock mudstone samples consist mainly of SiO2, Al2O3+Fe2O3+MgO, LOI and relatively high CaO value, revealing the presence of smectite and sepiolite associated with feldspar, quartz and calcite. Barium and Rb are relatively high and constant in the mudstone, compared to the marl. Positive correlation between K2O and Rb+Ba in mudstone and marl samples as a function of the presence of K-bearing minerals, such as feldspar. Based on field evidence, mineralogical and geochemical determinations, the sepiolite is presumed to have formed authigenically either by coprecipate with calcite during calcification or by conversion from detrital smectite or direct precipitation under super saturation condition. Thus, sepiolite precipitated in a vadose zone from strongly evaporatived alkaline water rich in Si and Mg and low in Al at increased temperatures and advanced stage of marl formation. The Si, Mg, Al+Fe and Ca required for sepiolite formation and calcification were supplied in solution from the smectitic clays, ophiolitic units and related volcanic units and carbonates in the close area. © SGEM2013 All Rights Reserved by the International Multidisciplinary Scientific GeoConference SGEM.Öğe Mineralogy, geochemistry and genesis of the modern sediments of Seyfe Lake, Kirsehir, central Anatolia, Turkey(PERGAMON-ELSEVIER SCIENCE LTD, 2015) Onalgil, Nergis; Kadir, Selahattin; Kulah, Tacit; Eren, Muhsin; Gurel, AliSeyfe Lake (Kirsehir, Turkey) is located within a depression zone extending along a NW-SE-trending fault in central Anatolia. Evaporite and carbonate sediments occur at the bottom of the lake which is fed by high-sulfate spring and well waters circulating N-S through salt domes. The recent sediments of Seyfe Lake are deposited in delta, backshore, beach, mud-flat and shallow lake environments. In the mud-flat environment, calcite, gypsum, halite, and thenardite are associated with fine-grained detrital sediments. Sediments from the margin to the lake center are distributed as calcite, gypsum and halite thenardite, yielding an annular distribution pattern. An increase in Na2O, SO3, and S, and a decrease in CaO toward the lake center are due to sediment distribution. On the other hand, a positive correlation of SiO2 with MgO, K2O, Na2O, Al2O3, and Fe2O3 + TiO2 is attributed to the presence of smectite, illite and feldspar. In addition, a positive correlation of Sr and Ba with CaO is related to the amount of gypsum in the sediments. Strontium is associated with in situ gypsum crystals; it increases in the intermediate and central zones of the lake as a result of a relative increase in salinity toward the lake center. The association of Sr with gypsum in the sediments suggests that Ca and Sr were derived from Sr-bearing evaporites and their carbonate host rocks, which were the likely aquifers for the brine. The S- and O-isotopic compositions of sulfate crystals range from +19.1 parts per thousand to +21.7 parts per thousand and from +16.9 parts per thousand to +20.9 parts per thousand SMOW, respectively, suggesting precipitation in a closed lake system. A relative increase of oxygen and sulfur isotope ratios toward the lake center suggests dissolution of gypsum in the host rock, with contributions from circulating groundwater and sulfate reduction (possibly by bacterial reduction). Sr-87/Sr-86 isotope ratios range from 0.707286 to 0.707879, suggesting a non-marine Oligo-Pliocene evaporitic host rock source for precipitation in Seyfe Lake. The concentration of Sr- and S-isotope ratios in the gypsum crystals indicates formation by precipitation/recrystallization from brine rather than from seawater. (C) 2014 Elsevier Ltd. All rights reserved.Öğe MINERALOGY, GEOCHEMISTRY, AND GENESIS OF MUDSTONES IN THE UPPER MIOCENE MUSTAFAPASA MEMBER OF THE URGUP FORMATION IN THE CAPPADOCIA REGION, CENTRAL ANATOLIA, TURKEY(CLAY MINERALS SOC, 2014) Kulah, Tacit; Kadir, Selahattin; Gurel, Ali; Eren, Muhsin; Onalgil, NergisThe Upper Miocene Mustafapasa member of the Urgup Formation in the Cappadocia region consists predominantly of mudstones, sandstone, and conglomerate lenses with ignimbrite and basalt intercalations. The mudstones are an important source of raw materials for the ceramics industry in Turkey. A detailed mineralogical, geochemical, and genesis study of these materials has not been performed previously and the present study aims to fill that gap. The characteristics of mudstones of the Mustafapasa member were examined using X-ray diffraction, scanning and transmission electron microscopy, energy dispersive spectroscopy, and chemical analyses. Weathering products of ophiolitic and pyroclastic rocks were transported into the tectonically subsided zone where they accumulated as fluvial and lacustrine deposits. Weathering in the mudstones is evidenced by smectite flakes associated with relict pyroxene, rodlike amphibole, feldspar, and volcanic glass. The chemical composition of mudstones and their distribution suggest that the depositional basin was supplied with ophiolitic material in the south and ignimbrite material in the north. This interpretation is based on an increase in the quantity of feldspar and opal-A and a decrease in the Fe2O3+MgO/Al2O3+SiO2 ratio from south to north in the study area. The northward increases in Light Rare Earth Elements/Heavy Rare Earth Elements, La/Yb, Zr/Ni and Zr/Co ratios and Nb, Ba, Rb, Sr, and Eu in the mudstones of the Mustafapasa member with positive Eu anomalies suggest that the Fe, Mg, Al, and Si required to form smectite were supplied mainly through the decomposition of amphiboles, pyroxenes, feldspars, and volcanic glass during weathering processes. After the deposition of mudstones, relative increases in evaporation-controlled Ca, K, and Al in pore water favored the partial dissolution of Ca-bearing minerals and smectite flakes and in situ precipitation of calcite and traces of illite fibers under alkaline micro-environmental conditions during early diagenesis.Öğe Mixing processes in hydrothermal spring systems and implications for interpreting geochemical data: a case study in the Cappadocia region of Turkey(SPRINGER, 2014) Afsin, Mustafa; Allen, Diana M.; Kirste, Dirk; Durukan, U. Gokcen; Gurel, Ali; Oruc, OzcanMixing is a dominant hydrogeological process in the hydrothermal spring system in the Cappadocia region of Turkey. All springs emerge along faults, which have the potential to transmit waters rapidly from great depths. However, mixing with shallow meteoric waters within the flow system results in uncertainty in the interpretation of geochemical results. The chemical compositions of cold and warm springs and geothermal waters are varied, but overall there is a trend from Ca-HCO3 dominated to Na-Cl dominated. There is little difference in the seasonal ionic compositions of the hot springs, suggesting the waters are sourced from a well-mixed reservoir. Based on delta O-18 and delta H-2 concentrations, all waters are of meteoric origin with evidence of temperature equilibration with carbonate rocks and evaporation. Seasonal isotopic variability indicates that only a small proportion of late spring and summer precipitation forms recharge and that fresh meteoric waters move rapidly into the flow system and mix with thermal waters at depth. H-3 and percent modern carbon (pmC) values reflect progressively longer groundwater pathways from cold to geothermal waters; however, mixing processes and the very high dissolved inorganic carbon (DIC) of the water samples preclude the use of either isotope to gain any insight on actual groundwater ages.Öğe PALEOCLIMATIC INTERPRETATIONS OF THE LATE MIOCENE/PLIOCENE KOMUSINI FORMATION, CENTRAL TURKEY: PALEOSOL AND FLUVIAL SUCCESSION(STEF92 TECHNOLOGY LTD, 2015) Gurel, AliThe late Miocene/Pliocene was characterized by high global temperatures (the Messinian salinity crisis), and during this epoch went the Mediterranean Sea into a cycle of partly or nearly complete desiccation throughout the latter part of the Messinian age. The marine Mediterranean Sea area has been studied from widely different perspectives. However, continental paleoenvironmental and paleoclimatic records of the late Miocene surrounding the Mediterranean area are very limited in their spatial extent. The study area (Konya-Kulu) is situated in northwestern part of the Tuzgolu basin in Central Anatolia, which is the largest intermontane basin in Turkey [1]. The paleosols and fluvio-lacustrine sedimentary rocks (conglomerate, sandstone and limestone) of Komisini Formation were described in detail and analyzed for geology, mineralogy, and these were characterized using petrographic and scanning electron microscope (SEM), X-ray diffractometry (XRD). Paleosols occurs in sequences with in the whole stratigraphic profile. It is recognized that they are histosol, aridisols, inceptisols, locally associated with, oxisols, according to the soil taxonomy [2]. Red colored palaeosols formed within these terrestrial sedimentary rocks under near surface or surface conditions, and comprise predominantly of quartz, feldspar, opal-CT, serpentine, calcite, dolomite, gypsum, hematite and clay minerals, such as smectite, chlorite, palygorskite and illite. Gypsum, smectite and chloride dominate at the base of the profile, whereas the palygorskite increase upward of the sections. The sedimentary rocks such as, conglomerate, sandstone and limestone formed in fluvio-lacustrine environment. The alteration of the ophiolitic and carbonate rich basement rocks caused the depletion of SiO2, Al2O3+Fe2O3, TiO2 and K2O by the precipitation of palygorskite, smectite, chlorite, +/- illite in palaeosols. The appearance of limestone and palygorskite from the upper profile level is suggestive of a shift to more arid or more seasonal conditions that is equivalent with a prominent change in sediment provenance and these indicate decrease in sedimentation rate during the latter part of the late Miocene/Pliocene.
