The mineralogy,geochemistry, and suitability for ceramic applications of Akharım (Afyonkarahisar,W Turkey) kaolinitic clay

Kaolinitic clays associated with sedimentary rocks cover widespread in the Yeniköy formation from the Akhar?m district, (Afyonkarahisar, W Anatolia). Due to the proximity to the ceramic industry areas such as Kütahya and U?ak Province of Turkey, the clays in the Akhar?m district have been intensively exploited for the last few years. The Akhar?m kaolinitic clays were hosted by Middle-Upper Miocene-aged Yeniköy formation and divided into two parts as northeastern and southwestern via normal fault. The alteration degree increases from lower levels to surface in the NE part of deposit. Besides layered structure in their N70° W/30° SW direction and gray-beige, yellowish brown colored in SW part. This study focused on mineralogy, geochemistry, and ceramic properties of kaolinitic clays. X-ray diffraction (XRD) and scanning electron microscope (SEM) analysis, chemical, physical, and mechanical tests were conducted on studied samples from the wall of clay quarry. Akhar?m clay deposits consist of mainly kaolinite and quartz. Additionally, they include smectite, biotite, feldspar, jarosite, calcite, and hematite minerals. Akhar?m clays are characterized with their moderate plasticity (PL = 17.07–24.09), low water absorption (3.64–9.53 wt.%), low linear shrinkage (8.08–15.55 wt.%), high bending strength (17.72–32.69 N/mm²), and ideal lightness values (L* = 46.50–82.74) and color values (a* = 4.71–29.87; b* = 14.67–28.72). These properties vary related with mineralogical and geochemical features of Akhar?m clays. In conclusion, Akhar?m clays have desired specifications for floor and wall t to their mineralogical, geochemical, and ceramic properties.     

Hydrogeochemical study of the thermal and mineralized waters of the Banaz (Hamamboğazi) area,western Anatolia,Turkey

The Hamamboğazi spa in western Turkey was built around natural hot springs with discharge temperatures in the range of 30–54°C; the waters have near neutral pH values of 6.50–7.10 and a TDS content between 2,694 and 2,982 mg/l. Thermal water with a temperature of 47.5–73°C has been produced at 325 l/s from five wells since 1994, causing some springs to go dry. A management plan is required in the study area to maximize the benefits of this resource, for which currently proposed direct uses include heating in the district and greenhouses, as well as balneology in new spas in the area. The best use for the water from each spring or well will depend on its temperature, chemistry and location. The thermal waters are mixed Na–Mg–HCO₃–SO₄ fluids that contain a significant amount of CO₂ gas. The chemical geothermometers applied to the Hamamboğazi thermal waters yield a maximum reservoir temperature of 130°C. Isotope results (¹⁸O, ²H, ³H) indicate that the thermal waters have a meteoric origin: rainwater percolates downward along fractures and faults, is heated at depth, and then rises to the surface along fractures and faults that act as a hydrothermal conduit. The basement around the Banaz Hamamboğazi resort is comprised of Paleozoic metamorphic schist and marbles exposed 8 km south and 15 km north of Banaz. Mesozoic marble, limestone and ophiolitic complex are observed a few km west and in the northern part of Banaz. These units were cut at a depth of 350–480 m in boreholes drilled in the area. Overlying lacustrine deposits are composed of fine clastic units that alternate with gypsum, tuff and tuffites of 200–350 m thickness. The marble and limestones form the thermal water aquifer, while lacustrine deposits form the impermeable cap.     

Palaeoseismology of the Havran-Balıkesir Fault Zone: evidence for past earthquakes in the strike-slip-dominated contractional deformation along the southern branches of the North Anatolian fault in northwest Turkey

The Havran-Bal?kesir Fault Zone (HBFZ) is one of the major active structures of the Southern Marmara Region, which has been shaped by the southern branch of North Anatolian fault since the Pliocene. HBFZ is a 10–12 km wide, 120 km long, right-lateral strike-slip fault zone that consists of two ENE-striking main faults, namely, the Havran-Balya and Bal?kesir faults. The 90-km-long Havran-Balya fault exhibits right-stepping en echelon geometry and is made up of (1) Havran, (2) Osmanlar, (3) Turplu and (4) Ovac?k fault segments. On the eastern part, the 70-km-long Bal?kesir fault is divided into two fault segments; (1) Gökçeyaz? and (2) Kepsut. We estimated the long-term slip rate between 3.59 and 3.78 mm/yr using river offset. The Kepsut, Gökçeyaz? and Ovac?k fault segments are capable of generating an earthquake with a moment magnitude of up to 7.2. Detailed palaeoseismological studies show that the HBFZ is responsible for some surface faulting earthquakes with an average recurrence interval of 1000–2000 years during the late Holocene. Considering the fact that there was no evidence of a surface-ruptured earthquake for 2000 years, it can be stated that there is a seismic gap on the Gökçeyaz? fault segment.     

Hydrogeochemical study of the Terme and Karakurt thermal and mineralized waters from Kirşehir Area,central Turkey

The Terme and Karakurt thermal resorts are located in the center of Kirşehir city in central Anatolia. Thermal waters with temperatures of 44–60°C are used for central heating and balneologic purposes. Paleozoic rocks of the Kirşehir Massif are the oldest units in the study area. The basement of the Massif comprises Paleozoic metamorphic schist and marbles which partly contain white quartzite layers of a few tens of cm thickness. The metamorphic schists which are cut by granites of Paleocene age are overlain by horizontally bedded conglomerate, sandstone, claystone, and limestone of upper Paleocene-Eocene age. Among the thermal and cold waters collected from the areas of Terme and Karakurt, those from thermal waters are enriched with Ca–HCO₃ and cold waters are of Ca–Mg–HCO₃ type waters. The pH values of samples are 6.31–7.04 for the thermal well waters, 6.41 for thermal spring, 7.25 and 7.29 for the cold waters, and 7.52 for the Hirla lake water. EC values are 917–2,295 μS/cm for the thermal well waters, 2,078 μS/cm for thermal spring, and 471 and 820 μS/cm for the cold springs. The lowest TDS content is from water of T10 thermal well in the Terme area (740.6 mg/l). The hot and cold waters of Terme show very similar ion contents while the Karakurt hot waters at western most parts are characterized by distinct chemical compositions. There is ion exchange in thermal waters from the T5 (5), T6 (6), T12 (7), and T1 (8) wells in the Terme area. The thermal waters show low concentrations of Fe, Mn, Ni, Al, As, Pb, Zn and Cu. Waters in the study area are of meteoric origin, and rainwater percolated downwards through faults and fractures, and are heated by the geothermal gradient, later rising to the surface along permeable zones. δ¹³C_VPDB values measured on dissolved inorganic carbon in samples range from −1.65 to +5.61‰ for thermal waters and from −11.81 to −10.15‰ for cold waters. Carbon in thermal waters is derived from marine carbonates or CO₂ of metamorphic origin while carbon in cold waters originates from freshwater carbonates.     

Deterministic approach to the seismic hazard of dam sites in Kızılırmak basin,Turkey

Dams constructed on the seismically active regions have a high-risk potential for downstream life and property. Strong ground motion can result in instability of the dam and strength loss of foundation. Active faults within the foundation of dam have the potential to cause damaging displacement of the structures. Appropriate design measures should be considered to obtain rational solution to the problem of catastrophic release of water from the reservoir, and especially to resist earthquake loads. Safety concerns for dams under the earthquake loads involve the seismic hazard evaluation of dam site for the overall stability of structure. Various types of analyses can be used, ranging from a simplified analysis to more complex procedures based on ground motion parameters and response spectra. This paper briefly evaluates seismic hazard analyses for dam structures, and introduces the analyses for thirty-six dams with height ranging from 15 to 195 m in Kızılırmak basin, Turkey. The seismic hazard analyses have indicated that peak ground acceleration varies within a wide range (0.09–0.45 g) for the dam sites of the basin.     

Groundwater circulation in the allochthonous limestone units between Lake Girdev and Kazanpınarı Spring, Antalya, southwestern Turkey

 The aim of the study is to investigate the interaction between waters of Lake Girdev and groundwater in the allochthonous limestone units exposed in the area between Lake Girdev and Kazanpınarı Spring, southwestern Turkey. The features analyzed include the flow direction and apparent groundwater velocity, their relationship with Lake Girdev, and the effect of lithological and structural features on the groundwater circulation. The results of a fluorescein tracer test indicate that groundwater flows east-northeast and the apparent flow velocity ranges from 26.2 to 35.6 m h^–1 between the injection site and various observation points. Tritium data suggest that the water of Lake Girdev and groundwater are probably similar in age, and oxygen-18 isotope data indicate that water derived from Lake Girdev is the main source of recharge to the aquifer. The aquifer is fed not only by Lake Girdev but also by rainfall percolating through allochthonous limestones; together, these provide the discharge of springs in Elmalı Polje. The permeability of the allochthonous limestone aquifer has been enhanced as a result of jointing and faulting. Received, June 1997 / Revised, June 1998, March 1999 / Accepted, July 1999     

Hydrochemical and isotopic properties of the Mahmutlu and Bağdatoğlu mineralized thermal springs, Kırşehir, Turkey

The present study identifies the hydrochemical and isotopic properties of the Mahmutlu and Ba?dato?lu mineralized thermal springs in K?r?ehir province, a geothermal field in central Anatolia, Turkey. Based on these properties, a hydrogeological regime is proposed in order to explain the Mahmutlu–Ba?dato?lu geothermal system. The relation between the concentrations of the environmental stable isotopes deuterium and oxygen-18 in the water is similar to the relationship in global meteoric water, indicating that the water is of meteoric origin. Evaluation of the geochemical characteristics of the water reveals that these two thermal springs belong to the same hydrogeological system. The hydrogeological system comprises a fractured limestone member of the Çevirme Formation and the Kervansaray Formation as reservoir rocks, and the Delice?rmak Formation as an overlying aquitard. The waters of the Mahmutlu and Ba?dato?lu springs are mainly of the Na-Cl-SO4 type that originate from the Pohrenk evaporite. The thermal waters are undersaturated with respect to calcite, dolomite, halite, and gypsum. The δ 18O and δ 2H contents indicate a δ 18O shift in the Mahmutlu and Ba?dato?lu waters. The temperature range of the two reservoirs is estimated to be 98–158?°C, on the basis of Na+K+Ca and SiO2 geothermometers.     

Origin,petrogenesis and geodynamic implications of the early Eocene Altınpınar adakitic andesites in the eastern Sakarya Zone,northeastern Turkey

Early Cenozoic magmatism in the eastern Sakarya Zone (NE Turkey) provides an important constraint on the regional tectono-magmatic evolution of the region. Early Eocene syn-collisional adakitic rocks are observed as small stocks with outcropping areas commonly less than 10 km². This study presents petrography, whole-rock geochemistry and Sr-Nd-Pb isotope data, as well as in-situ ⁴⁰Ar/³⁹Ar age constraints on one of these adakitic andesites in the Altınpınar area of Gümüşhane, and discusses source region, petrological processes and geodynamic setting prevailed during their genesis. Andesites commonly show microlitic porphyric and vitrophyric porphyric textures, and include significant amounts of mafic microgranular enclaves (MMEs). Plagioclase, hornblende, Fe-Ti oxides and minor pyroxene are the main mineral phases. In-situ ⁴⁰Ar-³⁹Ar amphibole dating constrains the cooling age of andesites into a time span from 52.8 ± 1.3–48.8 ± 1.9 Ma. Andesites are medium to high-K calc-alkaline and display most of the signatures typical of those of the adakites. They are characterized by moderate MgO (1.7–4.1 wt%), low Y (9−14 ppm), Yb (0.9–1.5 ppm), and HREE and high Sr (325−964 ppm) contents, and high Sr/Y (36–76) ratios. ⁸⁷Sr/⁸⁶Sr_(t) (0.704948−0.705100) and ¹⁴³Nd/¹⁴⁴Nd_(t) (0.512588−0.512628) ratios are in the isotopic range of the adakites. All these geochemical and isotopic data suggest that the parental magma of adakitic andesites has been produced by partial melting of oceanic basalts under amphibole-eclogite facies conditions during the breakoff of the northern Neotethyan oceanic slab.     

Hydrogeochemical factors effecting the scaling problem in Balçova geothermal field,İzmir, Turkey

Reservoir fluid compositions have been assessed from analytical data on water samples collected from thermal and cold waters in Balçova geothermal field. The results of mineral equilibrium modelling indicate that the waters, with some exceptions, are systematically supersaturated with respect to calcite, aragonite, dolomite, chalcedony and quartz, but undersaturated with respect to amorphous silica, celestite, anhydrite and gypsum and undersaturated or supersaturated with respect to barite, low-albite, K-feldspar, gibbsite and Fe(OH)₃(a). Calculation of mineral saturation states and geochemical analyses of scale and field observations show that carbonate minerals (calcite, aragonite and dolomite) are most likely to be precipitated as a scale type. Besides carbonates, scale formation risk of amorphous silica, Fe(OH)₃(a), anhydrite, barite and celestite minerals should be taken into account in some wells and surface equipment. Most of the waters, with some exceptions, have carbonate scaling risk at all temperatures, whereas the other scaling risks only exist over a limited temperature range. While silica, Fe(OH)₃(a) and barite show a scaling tendency at low temperatures, anhydrite and celestite scaling occurs at higher temperatures.     

Mineral and thermal waters of the Ipelská Pahorkatina hillyland

 Mineral and thermal waters occur at Kalinciakovo, Santovka, Dudince, Slatina and Turovce, in the inner side of the Western Carpathian arc, the south-western margin of the Central Slovak Neovolcanics, and on the so-called Levice spring line. They are important sources of mineral waters for Slovakia, which are used for different purposes (bathing therapy, bottling, recreation). The mineral and thermal waters of Dudince have an extraordinary position among them. The mineral water with its physico-chemical composition and content of gasses enables its wide use for bathing therapy and it occupies a special position among the mineral waters of the Carpathian arc. Received: 9 November 1998 · Accepted: 2 March 1999     

Hydrochemistry and environmental isotope study of the geothermal water around Beypazarı granitoids,Ankara, Turkey

Hydrochemical analysis results suggest four different water types: bicarbonate dominant water (facies-I), sulfate dominant cold brine water (facies-II), sodium-bicarbonate dominant thermal water and thermal and mineralized water (facies-III), and sulfate–chloride dominant thermal and mineralized water (facies-IV). The mineral content/salinity of the water is related to the ions that these waters dissolve from the minerals on the rocks during infiltration and circulation in the saturated zone. Gypsum cover units that exist on the granitoids in the region is the main factor for the ion increase in the facies III geothermal water similar to the cold brine water (facies II). Isotopic analyses indicate that the thermal springs (Dutlu bath spring, Aya? bath well, Çoban bath well and Kapullu bath spring) are of meteoric origin and receive recharge from precipitation in the Beypazar? granitoids and around gypseous formations with elevations of about 950–1,150 m. Karakaya bath well and Il?ca bath spring thermal water points are recharged from the Bilecik limestone hills, Tekke volcanics and ?ncedoruk Formations. Karakoca mineral spring of thermal and mineralized water is recharged from out of the study area. According to oxygen-18 (SO₄^2?) and sulfur-34 (SO₄^2?) contents, sulfate in water samples from Aya? and Dutlu resorts as well as Çoban bath is derived from the gypsum of Kirmir Formation as the primary source. Sulfates of the Kapullu bath water and Karakoca mineral water originate from secondary sources such as pyrite oxidation and bacteriological reduction.     

Geochemical characteristics of Kırka (Sarıkaya) borate deposit,northwestern Anatolia,Turkey

The K?rka borate deposit was deposited in a Miocene lacustrine basin which is closely associated with volcanic activity which lasted from Paleogene to the beginning of Quaternary. Borate mineralization alternates with claystone, mudstone, tuff and fine-layered limestone and mostly shows a lenticular structure. The mineral paragenesis is composed of borax, tincalconite, ulexite, kurnakovite, probertite, tunellite, colemanite, dolomite, smectite group minerals, illite and some firstly reported minerals for the K?rka deposit including hydrochloroborite, brianroulstonite, hilgardite-4M and searlesite minerals. In comparison to average values of earth crust, concentrations of Cs, Sr, Li, As and Se were significantly enriched with respective rates of 21, 15, 14, 3 and 188 folds. Regarding KY, KS1 and KS2 locations, there are differences in both element abundances and their geochemical tendencies which are attributed to variations in discharge regime and physico-chemical conditions of the depositional environment. Independent behaviour of B₂O₃ might indicate that boron is not associated with clays and carbonates and, therefore, most part of boron must be derived from volcanic activity (hydrothermal solutions, gases). REE data indicate that the K?rka borate deposit was formed in a sedimentary environment where highly alkaline (high pH) hydrothermal solutions also took part in borate precipitation process.     

Natural and induced sinkholes of the Obruk Plateau and Karapınar-Hotamış Plain,Turkey

The number of sinkholes (locally known as obruks) has increased rapidly in recent years near Karap?nar, located in the semi-arid Konya Closed Basin in Central Anatolia. Nineteen sinkholes have formed in the last 33 years (1977–2009) as a result of the collapse of cavity roofs in the Neogene lacustrine limestone in the Obruk Plateau and beneath Quaternary lake sediments in the Karap?nar-Hotam?? Plain. Of these, 13 have formed within the past 4 years (2006–2009). The Obruk Plateau takes its name from the presence of several hundred paleo-sinkholes which formed as a result of natural processes during the Quaternary period. More recently, human activity has induced the formation of new sinkholes, which presents a hazard to life and property. Changing agricultural patterns have led to the opening of thousands of deep wells in recent years, and increased water pumping currently exceeds the sustainable yield of the aquifer. Thus the formation of sinkholes has been triggered by a combination of natural and human causes. The groundwater level has dropped almost 24 m in the vicinity of Karap?nar during the last 26 years (1983–2008). Approximately 8 m of this drop occurred within the 4 years prior to the study (2005–2008). Legally-binding precautions must be taken to prevent further water table decline, in order to decrease sinkhole formation within the basin in the years to come.     

The Taraklı Flysch in the Boyali area (Sakarya Terrane,northern Turkey): Implications for the tectonic history of the IntraPontide suture zone

In the Boyal? area, northern Turkey, the tectonic units of the ?stanbul–Zonguldak Terrane and the IntraPontide suture zone are thrust over the deposits at the top of the Sakarya Terrane, known as Tarakl? Flysch. It consists of Early Maastrichtian–Middle Paleocene turbidite and mass-gravity deposits, whose source mainly corresponds to the ?stanbul–Zonguldak Terrane, and, with a lesser extent, to the IntraPontide suture zone. These deposits were sedimented in a foredeep basin developed during the convergence between Sakarya and Eurasian continental microplates. In the Late Paleocene–Early Eocene time span, the Tarakl? Flysch was deformed (D1 phase) during the closure of the foredeep basin. In the Miocene time, the strike-slip tectonics (D2 phase) related to the North-Anatolian fault produced further deformations of the Tarakl? Flysch.     

Estimation of environmental impacts on the water quality of the Tahtalıdam watershed in İzmir, Turkey

Water pollution is a widespread problem in different areas of the world. Some of these problems originated from point contamination sources and widespread contaminant outlet sources which are observed in every country. The major elements and chemical loads of surface water have been dominated by constituents derived directly or indirectly from human activities and/or industrial practices that have increased additives in the last several decades. The point sources of contamination may result from the direct wastewater discharges to the dam sites, which are considered to be the most commonly encountered water pollution problems. One of these problems is the eutrophication process which usually occurs in the static water mass of lakes and other surface water reservoirs. This process may be caused by the continuous increase of nitrogen and phosphorus contents and decrease of O₂ level in water causing an anaerobic condition which may stimulate algae-growth flow in these water bodies, consequently reducing the quality of water. Of course, there are many research methods for determining the various kinds of water pollution. In this research, the hydrochemical parameters were evaluated to estimate the types of pollution sources, the level of pollution, and its environmental impacts on the Tahtal dam reservoir.     

Assessment of water quality and pollution of the Lake Seyfe basin, Kırşehir, Turkey

Lake Seyfe is located in a closed basin near K?r?ehir in the central Anatolian region, Turkey. The aim of this study is to evaluate the groundwater quality and effects of lithogenic contamination carried out in the Lake Seyfe basin, which is represented by various lithologies and groundwater types. Seyfe, Horla and Akp?nar springs are recharged through marbles at the western and southwestern of the basin are ultimately and discharged into the K?z?l?rmak Formation and Lake Seyfe. The waters of deep wells drilled into the marbles are of bicarbonate type (type I) in the Ca²⁺–Mg²⁺–HCO₃ ^? and Ca²⁺–HCO₃ ^? facies. Özlühüyük spring and waters from most of trenches and shallow wells, which are fed by the K?z?l?rmak Formation, have a mixed (type II) composition in the Ca²⁺–Mg²⁺–HCO₃ ^?–Cl^? facies. Groundwater in the alluvium and K?z?l?rmak Formation along Lake Seyfe has a salty (type III) character in the Na⁺–Cl^? facies. The main reasons of formation and change of the groundwater salinity and hydrochemical facies in the Seyfe basin are causing the various (a) lithogenic pollution and heterogeneity of the K?z?l?rmak Formation, (b) salinity of the upper soil zones, and (c) evaporation of the trench and channel waters open to the atmosphere. Considering parameters such as sodium hazard, specific conductivity, bicarbonate and carbonate hazards, waters in the study area are generally suitable for agricultural usage.