Petrographic and geochemical features of the dolostones at the Gölboğazı Formation (Upper Devonian), Southwest Konya,Turkey

This paper describes the occurrence of dolostone and the mechanism of dolomitization of the Upper Devonian Gölbo?az? Formation in the allochthonous Taurus Mountains Alada? unit in Turkey. The Upper Devonian Gölbo?az? Formation carbonates, with dominant ostracod-bearing mudstone and wackestone, formed tidal and subtidal environments, and some of these rocks were dolomitized from shallow to deep burial. On the basis of the field, the petrographic and geochemical features, four different replaceable and cement dolostone phases have been recognized. The replacive dolostones contain (1) very fine to fine crystalline planar-s dolostone (df1), (2) medium to coarse crystalline planar-s to planar-e dolostone (df2), (3) coarse to very coarse crystalline non-planar-a dolostone (df3), and (4) coarse to very coarse crystalline planar dolostone cement (df4). The replacive dolostones are disordered to moderate the ordered and calcium-rich. They are non-stoichiometric and have 46–59 mol% CaCO₃ and 41–54 mol% MgCO₃ total contents. The df1 dolostones have MgCO₃ contents of 41–54 mol%, the df2 dolostones have 41–53 mol%, the df3 dolostones have 49 mol%, and the df4 dolostones have 49–50 mol%, respectively. The Gölbo?az? dolostones have δ¹⁸O values of ?9.44 to ?2.20‰ Vienna Pee Dee Belemnite (VPDB) and δ¹³C values of ?1.58 to +2.52 VPDB. Sr, Na, Mn, and Fe concentrations of replacive dolostones are 74–184, 148–593, below detection level (bdl)–619, and 1049–9233 ppm, respectively. The petrographic and geochemical data demonstrate that the replacive dolostones occurred prior to the chemical compaction at shallow to intermediate burial depths from Late Devonian seawater and/or seawater lightly modified by water–rock interaction process and later recrystallized by basinal brines at increasing burial depths and temperature. The North American Shale Composite-normalized rare earth element values of both limestone and dolostone show very similar rare earth element patterns characterized by slightly or considerably negative cerium (Ce) anomalies and a clear depletion in all rare earth element species. The dedolomitization observed in the Gölbo?az? Formation is thought to occur by the oxidizing effect of the meteoric water in the shallow burial environment during the telodiagenesis.     

Petrology of Al- and Cr-rich ophiolitic chromitites from the Muğla,SW Turkey: implications from composition of chromite,solid inclusions of platinum-group mineral,silicate, and base-metal mineral,and Os-isotope geochemistry

Ultramafic rocks around the city of Muğla in SW Turkey are represented by mantle peridotites depleted to various degrees, ranging from cpx-rich harzburgites to depleted harzburgite and dunite. Cpx-rich harzburgites are thought to be the residua left after extraction of MORB-type basalt, from which high-Al chromitite [49.2 < Cr# = 100 × Cr/(Cr + Al) < 53.5] crystallised with a higher proportion of ¹⁸⁷Os/¹⁸⁸Os (average of 0.1361). However, depleted harzburgites are assumed to be the residua left after extraction of hydrous boninitic melt produced by second stage partial melting of already depleted mantle due to a subducting slab, from which high-Cr chromitites (64.2 < Cr# < 85.9) with lower and heterogeneous ¹⁸⁷Os/¹⁸⁸Os ratio (average of 0.1324) were crystallised as a result of melt–rock interaction in a supra-subduction environment. Dunites around the chromite deposits are considered to be the product of melt–peridotite interaction. Most of the chromitites contain high-Cr chromite and display enrichment in IPGE (Os, Ir, Ru) over PPGE (Rh, Pt, Pd), with PGE concentrations between 61 and 1,305 ppb. Consistently, laurite-erlichmanite series minerals with various Os concentrations are found to be the most abundant PGM inclusions in chromite. Os–Ir–Ru alloy, irarsite, and kashinite, as well as Pt–Fe alloy and Pt-oxide, which are not common in ophiolitic chromitites, were also detected as magmatic PGM inclusions. Pentlandite, millerite, and, rarely heazlewoodite form the magmatic inclusions of base-metal sulphide. The presence of olivine and clinopyroxene, as well as hydrous silicate inclusions such as amphibole and phlogopite, in high-Cr chromitite supports the idea that high-Cr chromitites were formed in a supra-subduction environment.     

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.     

Pyritized mudstone and associated facies in the Permian–Triassic boundary of the Çürük Dağ section,Southern Turkey

This paper is the first study of pyritized mudstones (PM) in the Permian–Triassic (P–T) boundary section of the Çürük Da? (Taurus, Antalya Nappes, Turkey). The mudstones were generally formed as lensoidal-shaped layers or infill materials within nodular platform limestones (hardground). Normal marine fauna is diminished in the pyritized limestones, whereas tube-like microorganisms are apparently increased with the association of pyrite crystals consisting of both framboidal and cubic crystals. The total rock volumes are up to 50–60% clay minerals and are mainly made up of in situ kaolinite and subordinate mixed layer clays (illite–vermiculite). Kaolinite preferentially developed on feldspar crystals, sometimes covering ostracoda bivalves together with gypsum micronodules composed of fan-shaped gypsum crystals. The origin of the kaolinite is, in situ, directly related to feldspar dissolution via heterotrophic bacteria. Thus, kaolinite is found along with bacterial structures. Other mineralogical compositions include established quartz (mostly β-quartz), gypsum crystals (100–200 μm) glauconite and magnetite. Magnetite grains comprise a minor amount (1–2%) and show some bacterial-induced crystal orientations. Glauconite is formed as an accessory mineral that occurs as infill material in biogenic grains. On the other hand, some microspheres represented by a silica-dominated composition are only observed in scanning electron microscopes (SEM) studies under high magnification. Isotope values (d34S) obtained from the pyritized mudstones show an isotopic heterogeneity that suggests that the pyritized mudstone consists of at least two components, with different sulphur-concentrations and d34S values.     

Genetic investigation and comparison of Kartaldağ and Madendağ epithermal gold deposits in Çanakkale,NW Turkey

Two epithermal gold deposits (Kartaldağ and Madendağ) located in NW Turkey have been characterized through the detailed examinations involving geologic, mineralogical, fluid inclusion, stable isotope, whole-rock geochemistry, and geochronology data.The Kartaldağ deposit (0.01–17.65 ppm Au), hosted by Eocene dacite porphyry, is associated with four main alteration types with characteristic assemblage of: i) chlorite/smectite–illite ± kaolinite, ii) quartz–kaolinite, iii) quartz–alunite–pyrophyllite, iv) quartz–pyrite, the last being characterized by three distinct quartz generations comprising massive/vuggy (early), fine–medium grained, vug-lining (early), and banded, colloform, comb (late) textures. Observed sulfide minerals are pyrite, covellite, and sphalerite. Oxygen and sulfur isotope analyses, performed on quartz (δ¹⁸O_(quartz): 7.93 to 8.95‰ and calculated δ¹⁸O_(H2O): − 7.95 to 1.49‰) and pyrite (δ³⁴S_(pyrite): − 4.8‰ and calculated δ³⁴S_(H2S): − 6.08 to − 7.20‰) separates, suggest a meteoric water source for water in the hydrothermal fluid, and an igneous source for the sulfur dissolved in ore-related fluids. Microthermometric analyses of primary fluid inclusion assemblages performed on quartz (late quartz generation) yield temperatures (Th) dominantly in the range of 245–285 °C, and generally low salinity values at 0 to 1.7 wt.% NaCl eq. Based on the quartz textures and the associated base metal concentrations, along with fluid inclusion petrography, the early vug-lining quartz is considered to have been associated with the mineralization possibly through a boiling and a late mixing process at > 285 °C.The Madendağ deposit (0.27–20.60 ppm Au), hosted by Paleozoic mica schists, is associated with two main alteration types: sericite–illite–kaolinite, and quartz–pyrite dominated by two distinct quartz generations i) early colloform, comb and banded quartz and ii) late quartz, forming the cement in hydrothermal breccia. Whereas oxygen isotope analyses of quartz (δ¹⁸O_(quartz): 9.55 to 18.19‰ and calculated δ¹⁸O_(H2O): − 2.97 to 5.54‰) suggest varying proportions of meteoric and magmatic sources for the ore bearing fluid, sulfur isotope ratios (δ³⁴S_(pyrite): − 2.2‰ and calculated δ³⁴S_(H2S): (− 3.63) to (− 3.75) ‰) point to an essentially magmatic source for sulfur with or without contribution from sedimentary sources. Microthermometric analysis carried out on primary fluid inclusion populations of a brecciated sample (early quartz), give a temperature (Th) range of 235–255 °C and 0.0 to 0.7 wt.% NaCl eq. salinity. Based on the textural relationship, base metal and high gold contents, the ore precipitation stage is associated with late stage quartz formation via a possible boiling process.The presence of alunite, pyrophyllite and kaolinite, vuggy quartz and covellite suggest a high-sulfidation type of epithermal deposit for Kartaldağ. On the other hand, Madendağ is identified as an adularia-sericite type owing to the presence of significant sericite, neutral pH clays (mostly illite, chlorite/smectite, and kaolinite), low temperature quartz textures (e.g., colloform, comb, and banded quartz), and limited sulfide minerals.Given the geographical proximity of Kartaldağ and Madendağ deposits, the similar temperature and salinity ranges obtained from their fluid inclusions, and the similar ages of igneous rocks in both deposits (Kartaldağ: 40.80 ± 0.36 to 42.19 ± 0.45 Ma, Madendağ: 43.34 ± 0.85 Ma) the mineralizing systems in both deposits are considered to be genetically related.     

Presence and tectonic significance of Cretaceous rudist species in the so-called Permo-Carboniferous Göktepe Formation,central Menderes metamorphic massif,western Turkey

A schist sequence of the central Menderes Massif, in which lenses of fossiliferous marbles are found, is observed in the southern flank of the Aydn Mountain, north of Kök (Aydn), around Erikavak village. These rocks have been considered as Permo-Carboniferous in age and are included in the Göktepe Formation of earlier studies. However, some rudist species are described from thickly bedded gray marbles that have a concordant contact with the overlying schist sequence. Although the rudists have been metamorphosed, it is observed that some contain fossils are well enough preserved to determine the following rudist fauna: Hippurites lapeirousei (GOLDFUSS), Hippurites nabresinensis FUTTERER, Hippurites cf. colliciatus WOODWARD. This rudist fauna dates the schist sequence as Santonian–Campanian. The schist sequence is overlain by a thick tectonostratigraphic pile of orthogneiss which has been interpreted as the Pan-African metamorphic core of the Menderes Massif. A widespread cataclastic and mylonitic zone is present between the underlying rudist-bearing marbles and the structurally overlying orthogneiss sequence. The existing kinematic studies in the footwall and hangingwall of this tectonic contact reveal two different phases of deformations, a contractional phase followed by an extensional phase. During the contractional event, which occurred at 36 Ma, the orthogneiss sequence was thrust faulted northwards over the schist sequence. This thrust fault was later reactivated as a low-angle normal fault beneath a supradetachment sedimentary basin of Early-Middle Miocene age. The fossil discoveries of this study and the existing kinematic studies reveal that a new structural model for the central Menderes Massif in which the tectonometamorphic units form a major southward closing recumbent fold needs to be reviewed.     

Planktonic foraminiferal biostratigraphy of the Coniacian-Maastrichtian sequences of the Bey Dağları Autochthon,western Taurides,Turkey: thin-section zonation

Planktonic foraminifer distributions in seventeen stratigraphic sections of Upper Cretaceous hemipelagic and pelagic sequences of northern Bey Da?lar? Autochthon (western Taurides) yield six biozones such as, Dicarinella concavata Interval Zone, Dicarinella asymetrica Range Zone, Radotruncana calcarata Range Zone, Globotruncana falsostuarti Partial Range Zone, Gansserina gansseri Interval Zone, and Abathomphalus mayaroensis Concurrent Range Zone. Two of the zones, Dicarinella concavata Zone and Dicarinella asymetrica Zone, are identified in the massive hemipelagic limestones of the Bey Da?lar? Formation, of Coniacian-Santonian age. They are characterized by scarce planktonic foraminifera and abundant calcisphaerulids. The other four biozones are determined from the cherty pelagic limestones of the Akda? Formation and indicate a late Campanian-late Maastrichtian time interval. The planktonic foraminifera observed in these four biozones are diverse, complex morphotypes (K-selection), suggesting open oceans. The assemblage of the Abathomphalus mayaroensis Zone shows that the latest Maastrichtian record is absent throughout the northern part of the autochthon. Two main sedimentary hiatuses are recognized within the Upper Cretaceous pelagic sequence. Early to middle Campanian and latest Maastrichtian-middle Paleocene planktonic foraminifera are absent in all measured stratigraphic sections. Hiatus durations differ between sections as a result of diachronism of onset of the hemipelagic and pelagic deposition and the post-Santonian and post-Maastrichtian erosional phases. Drowning event and the early-middle Campanian and latest Maastrichtian-middle Paleocene hiatuses in the pelagic sequence are attributed to regional tectonics during the Late Cretaceous.     

Gem-quality transparent diaspore (zultanite) in bauxite deposits of the İlbir Mountains, Menderes Massif, SW Turkey

Several m-thick, karst-unconformity-type metabauxite horizons in the İlbir Mountains of SW Turkey host open-space mineralization of gem-quality diaspore (trademarked as zultanite), associated with muscovite, hematite, ilmenite, chloritoid, and younger calcite. The hydrothermal-metamorphogenic mineralization occurs in fracture zones (veins and open structures) that crosscut the metabauxite horizons, but does not extend into the marble host rocks. The white to dark gray marble sequence (over 2,000 m in thickness) is of Cretaceous depositional age and was affected by Alpine (Paleogene) tectonometamorphism which caused the hydrothermal remobilization of primary bauxite components into crosscutting structures.     

Mineralogical,petrological, and geochemical studies of the Limahe mafic–ultramatic intrusion and associated Ni–Cu sulfide ores,SW China

The Limahe Ni–Cu sulfide deposit is hosted by a small mafic–ultramafic intrusion (800 × 200 × 300 m) that is temporally associated with the voluminous Permian flood basalts in SW China. The objective of this study is to better understand the origin of the deposit in the context of regional magmatism which is important for the ongoing mineral exploration in the region. The Limahe intrusion is a multiphase intrusion with an ultramafic unit at the base and a mafic unit at the top. The two rock units have intrusive contacts and exhibit similar mantle-normalized trace element patterns and Sr–Nd isotopic compositions but significantly different cumulus mineralogy and major element compositions. The similarities suggest that they are related to a common parental liquid, whereas the differences point to magma differentiation by olivine crystallization at depth. Sulfide mineralization is restricted to the ultramafic unit. The abundances of sulfides in the ultramafic unit generally increase towards the basal contacts with sedimentary footwall. The δ ³⁴S values of sulfide minerals from the Limahe deposit are elevated, ranging from +2.4 to +5.4‰. These values suggest the involvement of external S with elevated δ ³⁴S values. The mantle-normalized platinum-group element (PGE) patterns of bulk sulfide ores are similar to those of picrites associated with flood basalts in the region. The abundances of PGE in the sulfide ores, however, are significantly lower than that of sulfide liquid expected to segregate from undepleted picrite magma. Cr-spinel and olivine are present in the Limahe ultramafic rocks as well as in the picrites. Mantle-normalized trace element patterns of the Limahe intrusion generally resemble those of the picrites. However, negative Nb–Ta anomalies, common features of contamination with the lower or middle crust, are present in the intrusion but absent in the picrites. Sr–Nd isotopes suggest that the Limahe intrusion experienced higher degrees of contamination with the upper crust than did the picrites. The results of this study permit us to suggest that the parental magma of the Limahe intrusion was derived from picritic magma by olivine fractionation and contamination in a staging chamber at mid-crustal levels. Depletion of PGE in the sulfide ores in the Limahe intrusion is likely due to previous sulfide segregation of the parental magmas in the staging chamber. Sulfide mineralization in the Limahe intrusion is related to second-stage sulfide segregation after the fractionated magmas acquired external S from pyrite-bearing country rocks during magma ascent to the Limahe chamber. The abrupt change in mineralogical and chemical compositions between the ultramafic unit and the overlying unit suggests that at least two separate pulses of magma were involved in the development of the Limahe intrusion. We propose that the Limahe intrusion was once a wider part of a dynamic conduit that fed magma to the overlying subvolcanic dykes/sills or lavas. The ultramafic unit formed by the first, relatively more primitive magma, and the mafic unit formed by the second, relatively more fractionated magma. Immiscible sulfide droplets that segregated from the first magma settled down with olivine crystals to form the sulfide-bearing, olivine-rich rocks in the base of the intrusion. The overlying residual liquids were then pushed out of the chamber by the second magma. Critical factors for the formation of an economic Ni–Cu sulfide deposit in such a small intrusion include the dynamic petrologic processes involved and the availability of external sulfur. The Limahe deposit reminds us that small, multiphase, mafic–ultramafic intrusions in the region should not be overlooked for the potential of economic Ni–Cu sulfide deposits.     

Microtextural Characteristics and Origin of Dolomites in the Tepearasi Formation, SW of Beysehir-Konya, Turkey

The Tepearasi Formation of the autochthonous Geyikdagi Group in the Central Tauride Belt, SE of Beysehir, is Dogger in age and consists dominantly of massive limestones and greyish dolomites occurring within the middle to upper sections. The total thickness of the dolomitic levels ranges from 100-300 m and laterally extends 500-700 m. Three types of dolomite were distinguished through petrographic analyses: homogeneous, mottled (saddle-crystalline) and joint-filling dolomite, which were interpreted to have formed in two different stages, early diagenetic and late diagenetic. The homogeneous dolomite of the early diagenetic stage is light-coloured and monotonous-textured and shows the form of a dolosparite mosaic. The mottled dolomite formed in the late diagenetic stage is light- to dark-coloured and coarsely granular idiomorphic. The other type of late diagenetic dolomite, described as the joint-filling type, presents a crystal growth pattern from the joint walls towards the centre of the joint space. I     

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.     

Composition and origin of the Çaldağ oxide nickel laterite,W. Turkey

The Çalda? nickel laterite deposit located in the Aegean region of W. Turkey contains a reserve of 33 million tons of Ni ore with an average grade of 1.14% Ni. The deposit is developed on an ophiolitic serpentinite body which was obducted onto Triassic dolomites in the Late Cretaceous. The deposit weathering profile is both laterally and vertically variable. A limonite zone, which is the main ore horizon, is located at the base of the profile. A hematite horizon is located above the limonite, which in the south of the deposit is capped by Eocene freshwater limestones and in the north by a siliceous horizon. The deposit is unusual in lacking a significant saprolite zone with little development of Ni-silicates. The boundary between the limonite zone and serpentinite below is sharp with a marked decrease in concentrations of MgO from 13 to 1 wt.% over a distance of 2 mm representing the ‘Mg discontinuity’. Ni concentrations within goethite, the main ore mineral, reach a maximum of ~3 wt.% near the base of the limonite zone. Silica concentrations are high throughout most of the laterite with up to 80 wt.% silica in the upper portion of some profiles. The combination of a serpentinite protolith and a high water table at Çalda?, in association with an aggressive weathering environment in a tropical climate, resulted in the formation of an oxide-dominated deposit. The precipitation of silica may coincide with a change in climate with silica precipitation linked to an increase in seasonality. Additional variations within profile morphology are attributed to transportation during and after laterite development as a result of faulting, pocket type laterite formation and slumping, each of which produces a contrasting set of textural and geochemical features.     

Late Triassic rifting and Jurassic–Cretaceous passive margin development of the Southern Neotethys: evidence from the Adıyaman area,SE Turkey

Evidence of rifting and continental break-up to form the S Neotethys is found within the volcanic-sedimentary Koçali Complex. This is a folded, thrust-imbricated succession that includes lavas, volcaniclastic sediments, pelagic carbonates, radiolarites and manganiferous deposits. Interbedded ribbon cherts contain radiolarians of Late Triassic to Late Jurassic age. The lower part of the succession of Mid?-Late Triassic age (Tarasa Formation) is dominated by enriched mid-ocean ridge basalt (E-MORB). The overlying Late Triassic to Mid-Jurassic interval (Konak Formation) is characterised by intercalations of ocean island basalt and E-MORB. Taking account of structural position, the basalts erupted within the outer part of a continent–ocean transition zone. Continental break-up probably occurred during the Late Triassic (Carnian–Norian). Early to Mid-Jurassic lavas and volcaniclastic sediments record volcanism probably after continental break-up. In addition, the Karadut Complex is a broken formation that is located at a relatively low structural position just above the Arabian foreland. Pelagic carbonates, redeposited carbonates and radiolarites predominate. Radiolarians are dated as Early to Mid-Jurassic and Late Cretaceous in age. The pelagic carbonates include planktic foraminifera of Late Cretaceous age. The Karadut Complex resulted from the accumulation of calcareous gravity flows, pelagic carbonate and radiolarites in a relatively proximal, base-of-slope setting. After continental break-up, MORB and ophiolitic rocks formed within the S Neotethys further north. Tectonic emplacement onto the Arabian platform took place by earliest Maastrichtian time. Regional interpretation is facilitated by comparisons with examples of Triassic rifting and continental break-up in the eastern Mediterranean region and elsewhere.     

Evaluating the anthropogenic and geologic impacts on water quality of the Eğirdir Lake, Turkey

E?irdir Lake is the second largest fresh water lake with 482 km² surface area of Turkey. The lake is an indispensable water source for our country and region because of available water capacity and usage aims such as drinking-irrigation water, tourism, and fishing. However, especially contaminants located in the E?irdir Lake catchment affect the lake water quality negatively in times. Therefore, determination of the water quality of the lake has quite importance for region human health and sustainable usage of the lake. The major factors that control the quality of the E?irdir Lake water are agricultural activities in the basin, water–rock interaction, and domestic and industrial wastes. This study investigates the anthropogenic and geologic impact originated from pollution sources and water–rock interaction in the lake watershed basin to the E?irdir Lake water quality. For this purpose, geological, hydrogeological, and hydrological properties of the lake basin with point and nonpoint pollution sources were investigated. To determine the water quality of the lake, 48 water samples were collected especially from locations representing effects of pollutants in May and October 2009. The analysis results were compared with maximum permissible limit values recommended by World Health Organization and Turkish drinking water standards. The contents of all chemical and physical parameters are higher in dry periods than wet period, and water pollution was observed at discharge points of the streams into the lake. Also, pH, turbidity, potassium, chemical oxygen demand, ammonium, aluminum, iron, and lead concentrations were found to be above drinking water standards.     

Investigation of discharge and groundwater contamination characteristics around the Karasu Spring, Muş Area, Turkey

The study area is 35 km east of the city center of Mu, Turkey. The rock units in the area include Paleozoic Bitlis Metamorphites, Cenozoic flysch and Solhan Volcanities and Pliocene formations. A long-term discharge change was monitored in the Karasu spring. The amount of water discharged by the spring during June 3 and October 11, 2002 was 7.18×10⁶ m³ while its storage capacity during May 26 and November 11, 2002 was 4.42×10⁶ m³.NH₄ – N, NO₂ – N, NO₃ – N, total PO₄ – P, SO₄ and total organic carbon (TOC) contamination were determined in the recharge area of the spring and other well and spring waters in the vicinity. NH₄ – N, NO₂ – N, NO₃ – N, total PO₄ – P, SO₄ and total organic carbon contamination around the Budak, ivbai, Gölbai, Sazlikbai and Altinova villages are well above the drinking water standards of the Turkish Standard Institute (TSE) and World Health Organization (WHO) (1984). Similarly, water samples of K₄, K₅ and K₆ branches of the Karasu spring and S₁, S₂, S₃ and S₄ points in the swamp area yielded concentrations much more than limit values.     

Geology,geochemistry, and geochronology of Fe-oxide Cu (± Au) mineralization associated with Şamlı pluton,western Turkey

The Şamlı (Balıkesir) Fe-oxide Cu (± Au) deposit, one of several iron (+ Cu ± Au) deposits in western Turkey, is hosted by porphyritic rocks of the multi-phase Şamlı pluton and metapelitic–metadiabasic rocks of Karakaya Complex. Two successive mineralization events are recognized in the area as; i) early magnetite and sulfide and ii) late hematite–goethite-native copper (± Au). Alteration associated with the mineralization in Şamlı is characterized by four distinct mineralogical assemblages. They are, in chronological order of formation, (1) plagioclase–early pyroxene (± scapolite), (2) garnet–late pyroxene, (3) chlorite–epidote, and (4) chalcedony–calcite alteration. Geochemical, isotopic (Sr, Nd, O, S) and geochronological (Ar–Ar) data from alteration and magmatic rocks suggest a temporal and genetic link between the multiphase Şamlı pluton and the hydrothermal system that controls the Fe-oxide-Cu (± Au) mineralization. ⁴⁰Ar/³⁹Ar geochronology on hornblende and biotite separates of the Şamlı pluton yielded an age range between 23.20 ± 0.50 and 22.42 ± 0.11 Ma, overlapping with ⁴⁰Ar/³⁹Ar age of 22.34 ± 0.59 Ma from alteration.The close spatial and temporal associations of Şamlı mineralization with porphyritic intrusions, pervasive Ca-rich alteration (calcic plagioclase, andraditic garnet, diopsidic pyroxene, scapolite, and epidote) are considered as common features akin to calcic assemblages in typical IOCG deposits. Besides abundant low-Ti (≤ 0.5%) magnetite/hematite, high Cu–moderate Au (up to 8.82 ppm) association, structural control and lithologic controls of mineralization, low S-sulfide content (chalcopyrite > pyrite) in the deposit; and the derivation of causative magma from subduction-modified subcontinental lithospheric mantle under a transpressional to transtensional regime, are collectively considered as the features in favor of IOCG-type mineralization for the Şamlı deposit.     

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.