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Öğe Fluid Evolution of the Fe-Zn Skarn Deposits in the Çiftehan (Ulukışla-Niğde) Area, South-Central Turkey(Springer Nature, 2023) Sunkari, Emmanuel Daanoba; Lermi, Abdurrahman; Demir, YılmazThis study investigated the compositional variations of fluid inclusions in the different stages of mineralization at the Esendemirtepe and Horoz Fe-Zn skarns, south-central Turkey. The skarn zones in the study area consist of volcano-sedimentary sequences intruded by intrusive bodies and marble–schist in contact with granitoids. The primary ore minerals in both locations are magnetite and hematite, with subordinate sphalerite, chalcopyrite, pyrite, and pyrrhotite. The Esendemirtepe Fe-Zn skarn deposit is a typical deep exoskarn characterized by irregular disseminated hematite and magnetite assemblages with blebs of chalcopyrite, accompanied by calcite, quartz, and epidote at the contact between the volcano-sedimentary units and the skarn. The Horoz Fe-Zn skarn deposit is also a relatively deep endoskarn characterized by massive garnet crystals. Rhythmic banded crystallization of sporadic nodular-shaped sphalerite, quartz, and calcite developed along with the marble–schist skarn contact. Two-phase liquid-rich (L + V) fluid inclusions were observed in garnet, epidote, quartz, calcite, and sphalerite mineral assemblages. The average homogenization temperatures and calculated salinities in all stages of mineralization range from 155 to 600 °C and 0.53 to 23.1 wt.% NaCl equ., respectively. The eutectic temperatures also range from ?66.2 to ?21.2 °C, implying that the early stages were dominated by fluids that reflect an H2O-NaCl-CaCl2 system and become an H2O-NaCl system in the later stage. The continuous evolution history of the fluids reveals a gradual change from early high-temperature-salinity magmatic fluids to late relatively low-temperature-salinity mixed magmatic fluids due to interaction with meteoric-derived fluids. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.Öğe GEOCELEMICAL AND MINERALOGICAL ALTERATIONS ASSOCIATED WITH THE HOSTROCKS OF THE KANKOY VOLCANOGENIC MASSIVE SULFIDE (VMS) DEPOSIT (TRABZON, NE-TURKEY)(STEF92 TECHNOLOGY LTD, 2013) Lermi, Abdurrahman; Ciftci, EminThis paper is to investigate alterations of wall rocks in Kankoy deposit. Kankoy deposit which is a Cu-Zn-Pb type volcanogenic massive sulfide (VMS) deposit, situated in the western central part of the eastern Pontide tectonic belt. The deposit is hosted predominantly by tuff, tuff-breccia, and flow-banded breccia of dacite which are all late cretaceous in age. Samples were systematically collected from surface outcrops, drill cores and the mineralized zones (accessed through underground workings) and were studied through petrographical and geochemical analyses. The results showed that the footwall rocks were variably altered. Alteration mineralogy is usually consisted of three distinctive zones. The inner zone was characterized by presence of quartz and sericite, extensively overprinted by kaolinite in places. This zone was graded outward into a sericite-chlorite and further into chlorite-montmorillonite zones. Mass-change calculations revealed that Al, Zr, Ti, and Y behaved as the immobile elements during the alteration and in that felsic footwall rocks gained Fe, Si, Mg, K and ore forming constituents, respectively. The most characteristic chemical changes near the ore bodies occurred in Na and Ca contents. They both showed strong depletion, mainly due to plagioclase destruction by the hydrothermal fluids. Chlorite alteration was manifested by the replacement of feldspars and a decrease in sericite abundance related to a net addition of Fe and Mg to the system. The REE contents also varied considerably depending on mass-change effects related to alteration. On the contrary to the footwall rocks, mass-changes associated with the hanging wall rocks of the region were generally much smaller.Öğe Geochemical and mineralogical alterations associated with the hostrocks of the kankoy volcanogenic massive sulfide (VMS) deposit (Trabzon, ne-Turkey)(2013) Lermi, Abdurrahman; Ciftci, EminThis paper is to investigate alterations of wall rocks in Kanköy deposit. Kanköy deposit which is a Cu-Zn-Pb type volcanogenic massive sulfide (VMS) deposit, situated in the western central part of the eastern Pontide tectonic belt. The deposit is hosted predominantly by tuff, tuff-breccia, and flow-banded breccia of dacite which are all late cretaceous in age. Samples were systematically collected from surface outcrops, drill cores and the mineralized zones (accessed through underground workings) and were studied through petrographical and geochemical analyses. The results showed that the footwall rocks were variably altered. Alteration mineralogy is usually consisted of three distinctive zones. The inner zone was characterized by presence of quartz and sericite, extensively overprinted by kaolinite in places. This zone was graded outward into a sericite-chlorite and further into chlorite-montmorillonite zones. Mass-change calculations revealed that Al, Zr, Ti, and Y behaved as the immobile elements during the alteration and in that felsic footwall rocks gained Fe, Si, Mg, K and ore forming constituents, respectively. The most characteristic chemical changes near the ore bodies occurred in Na and Ca contents. They both showed strong depletion, mainly due to plagioclase destruction by the hydrothermal fluids. Chlorite alteration was manifested by the replacement of feldspars and a decrease in sericite abundance related to a net addition of Fe and Mg to the system. The REE contents also varied considerably depending on mass-change effects related to alteration. On the contrary to the footwall rocks, mass-changes associated with the hanging wall rocks of the region were generally much smaller. © SGEM2013 All Rights Reserved by the International Multidisciplinary Scientific GeoConference SGEM.Öğe Geochemistry, risk assessment, and Pb isotopic evidence for sources of heavy metals in stream sediments around the Ulukisla Basin, Nigde, southern Turkey(Tubitak Scientific & Technological Research Council Turkey, 2020) Lermi, Abdurrahman; Sunkari, Emmanuel DaanobaConcentrations of selected elements (Al, Fe, Mn, Mo, As, Cd, Cu, Cr, Ni, Co, Pb, Sb, and Zn) and Pb isotope ratios were determined in 53 sediments from Alihoca, Gumus, Horoz, and calut streams around the south-central Taurides (Ululusla Basin), Nigde, which is a known mining province in Turkey. Several pollution and risk assessment indices were used to assess possible heavy metal pollution in the stream sediments and the associated potential ecological risks. Concentrations of As, Cd, Cu, Cr, Ni, Co, Pb, Sb, and Zn were elevated in the streams located near ancient mines, active mines, and slag piles in the area, suggesting an influence from mining activities. The pollution assessment indices indicated that the sediments were significantly polluted by As, Cd, Sb, Zn, and Pb and moderately polluted by Cu, Ni, Cr, and Co. The sediments show very high potential ecological risk with As, Cd, Sb, and Pb as the principal contributors. Ni, Cr, As, Pb, Zn, and Cd exceeded the probable effect concentrations in most of the samples implying that their concentrations may frequently affect sediment-dwelling organisms. Multivariate statistical analyses indicate that the accumulation of heavy metals in the stream sediments is due to an interplay of anthropogenic activities (mining and agrochemical application) and geogenic processes (weathering of bedrocks and supergene alteration of base metal-rich mineralization). Pb isotopic tracing indicates that total Pb in the sediments (Pb-206/Pb-207 = 1.09-1.29) is primarily from weathering and dissolution of ultrapotassic rocks (Pb-206/Pb-207 up to 1.20) and galena (Pb-206/Pb-207 up to 1.21) from the Pb-Zn-Au deposits in the area with some anthropogenic input from mine slag piles (Pb-206/Pb-207 = 1.10).Öğe Hydrogeochemical controls and human health risk assessment of groundwater fluoride and boron in the semi-arid North East region of Ghana(Elsevier, 2019) Zango, Musah Saeed; Sunkari, Emmanuel Daanoba; Abu Mahamuda; Lermi, AbdurrahmanIn this study, eighty-eight (88) samples were collected from active boreholes in the North East region of Ghana and analyzed for concentrations of the hydrogeochemical parameters. This helped in understanding the hydrogeochemistry, spatial distribution, origin of groundwater F- and B and the level to which the underlying geology influences the F- and B. Human health risks of F- and B were also assessed based on the model of the US Environmental Protection Agency. Groundwater is alkaline in this area and the dominant hydrochemical facies is Na-HCO3 facies, which is a reflection of the predominant carbonate lithology of the Oti/Pendjari Group in the region. The study reveals that the F- concentrations range from 0.05 to 13.29 mg/L with an average value of 3.26 mg/L, suggesting that majority of the boreholes have F- concentrations higher than the acceptable limit (1.5 mg/L) of WHO. The B concentrations also vary from 0.03 to 5.13 mg/L with an average of 1.52 mg/L in excess of the guideline value of 0.5 mg/L. The groundwater F- and B threats, respectively affect about 70% and 82% of boreholes in the region particularly around the northeastern, southeastern, central, and western parts. F- and B are mainly coming from geogenic sources and are controlled by hydrogeochemical factors such as semi-arid climatic conditions of the region, alkaline nature of the water, water-rock interaction, intense weathering, ion exchange, mineral dissolution and precipitation. The human health risk assessment reveals that non-carcinogenic risk for F- and B is higher in children than the adult population. About 89% of children in the study area are exposed to initial symptoms of dental and skeletal fluorosis and have higher chances of cardio-protection since no health threat is currently reported for high B in drinking water. We recommend immediate action towards mitigating the high groundwater F- to safeguard the health and livelihood of the people.Öğe LATERİT JEOKİMYASI KULLANARAK WA-LAWRA BÖLGESİNDE OROJENİK ALTIN YATAKLARININ ARAŞTIRILMASI, ÖRNEK BİR UYGULAMA, KUNCHE, NW GANA(2018) Sunkarı, Emmanuel Daanoba; Twum, Michael Appıah; Lermi, AbdurrahmanBu çalışmada, Wa-Lawra kuşağı içinde yer alan Kunche (KB Gana) bölgesindeki lateritlerin mekânsal dağılımı,eser element dağılımları ve jeokimyasal birliktelikleri incelenmiştir. Kunche bölgesinde yaygın olan lateritörnekleri XRF ve ICP-MS yöntemleri kullanılarak analiz edilmiş, çok değişkenli jeoistatistik analizler kullanılarakbu veriler değerlendirilmiştir. Lateritler, lateritik duricrust (kalıntı lateritler) ve ferruginous duricrust (taşınmışlateritler) olarak sınıflandırılabilirler. Çok değişkenli istatistik sonuçları, bu kayaçlarda üç farklı elementbirlikteliği olduğunu (Fe, S, Pb, Co-Grup-1; Cu, Cr, As, Au, Ag-Grup-2; Mn, Ca, Ti, Ni, Rb, Sr, Zr, Y, Zn-Grup3) göstermiştir. Bu element grupları, taban kayaçları olan metavolkanitler ve içindeki altın yataklarının yoğunayrışması sonucu iz bulucu elementlerin ikincil dağılımı ile doğrudan ilişkili olduğunu göstermektedir. Medyanmutlak sapma metodu kullanılarak hesaplanan eşik değerler S (>% 0,41), Pb (> 48 ppm), Cu (46 ppm), As (134.2ppm) ve Ag (> 0.42 ppm) olarak tespit edilmiştir. Diğer yandan, çok elementli haritalama tekniği, Pb+Cu+As+Agelementlerinin bu yatakların araştırılmasında en iyi iz element birlikteliği olduğunu göstermiştir. Bu ilişki,özellikle kalıntı lateritler içinde aynı yöntemle hazırlanan Au dağılım haritasına oldukça benzer elipsoidal anomaliverdiği tespit edilmiştir.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 MINERALOGY AND GEOCHEMISTRY OF THE KIZILTEPE (CAMARDI-NIGDE) MN PROSPECT IN CENTRAL ANATOLIA, TURKEY(STEF92 TECHNOLOGY LTD, 2016) Lermi, Abdurrahman; Sonmez, Mustafa; Aydin, FarukThis paper is to investigate ore-alteration mineralogy and geochemical changes of wall rocks in Kiziltepe Mn mineralization (Camardi, SE-Nigde), which is located in Ulukisla Basin from the central part of the Turkey. Kiziltepe prospect, a fault controlled hydrothermal-type Mn mineralization, is hosted predominantly by Late Cretaceous to Early Tertiary volcanic and volcanoclastic rock series, which are submarine in character with trachytic to rhyolitic composition. After all samples were systematically collected from surface outcrops and the mineralized zones, they were investigated by petrographical and geochemical analysis. The results obtained from the microscopic and XRD analysis showed that the mineralization contained oxi-hydroxide Mn minerals such as manganite, pyrolusite, psilomelane, and manganese phosphate. Quartz, carbonates, sericite, clay minerals and barite are the gangue minerals. Quartz is ubiquitous and occurs both in the ore zone and in the wall rocks. Alteration mineralogy usually was formed fault-related to alteration zones. Alterations were characterized by presence of quartz and sericite, and locally extensively overprinted by kaolinite. Mass change calculations revealed that Al, Ti, and Y behaved as the least mobile elements during alteration and that footwall felsic rocks gained Fe, Si, K, Ca and ore forming constituents, respectively. The most characteristic chemical changes near the ore bodies were the Na depletion, mainly due to plagioclase destruction by the hydrothermal fluids. The BEE contents varied considerably depending on mass change effects related to alteration. An average grade of Mn in the fault zone has been reached about 22.47 %.Öğe New evidence concerning to the Nigde fault in the near east and south of the settlement area of the Nigde, central Anatolia, Turkey(International Multidisciplinary Scientific Geoconference, 2017) Sonmez, Mustafa; Balli, Fatih; Lermi, AbdurrahmanThe main purpose of this paper is to investigate of the Niğde Fault zone, which passes through the city of Niğde. The study area located in the south and eastern part of the Niğde Province, and crops out different types of geological units from Paleozoic to Cenozoic in that vicinity. These units are, from old to young, metamorphic rocks, which is known as Niğde Massif composed of Gümüşler, Kaleboynu, Aşıgediği formations, Üçkapılı granodiorite (Paleozoic to Mesozoic), Kızılkaya Ignimbrite (Upper Miocene to Pliocene), Karataş Volcanites (Middle Pleistocene), Quaternary fluvial sediments, talus and alluvium. The tectonics, basin development, volcanism and geomorphology of the Central Anatolia are largely under the control of three dominant faults. These are the NW-SE trending and strike slip Tuzgölü Fault, NNE to SSW trending and left lateral strike-slip Ecemiş Fault and NE to SW trending dip slip Niğde Fault. In order to obtain concrete geological information related to this fault, electric resistivity and self-potential (SP) measurements made 50 m interval on two profile, which was out the fault line vertically. SP and Electrical resistivity measurements made in 76 points along the first profile, 49 points along the second profile where located at SW and NE of the Niğde, separately. High Electrical resistivity and SP values were recorded at 10, 40, 45 points in the first profile and 11, 27 and 47 points in the second profile. These points are evaluated as an important finding of the existence of discontinuities of the Niğde Fault Zone, which is covered by young sediments. It is understood from the Electrical resistivity and SP data that the Niğde Fault Zone consisting of at least three segments (S1, S2, S3). The distance from the segment (S1), which is located in the South, to the NW margin of the Nigde Massif varies from 750 to 2500 m. These segments are parallel to each other extend in NE-SW direction. The NW edge of the massif is the fault scarp, which was retrograde towards to SE direction, in the Middle Miocene-Early Pliocene time. The presence of thick talus on the NW side of this fault zone supports this idea. © SGEM2017. All Rights Reserved.Öğe NİĞDE GD KESİMİNİN JEOLOJİSİ VE NİĞDE FAYINA İLİŞKİN YENİ BULGULAR(2018) Ballı, Fatih; Sönmez, Mustafa; Lermi, AbdurrahmanNiğde Fayı’nın özelliklerini ve alanın jeolojisini belirlemeye yönelik bu çalışma, Paleozoik’ten günümüze,birçok jeolojik birimi içeren Niğde ilinin güney ve doğu kesimini kapsar. Çoğunlukla metamorfik kayaçlardanoluşan bu birimler yaşlıdan gence doğru Gümüşler, Kaleboynu, Aşıgediği formasyonları, Üçkapılı Granodiyoriti,Kızılkaya İgnimbriti, Karataş Volkanitleri, Kuvaterner akarsu çökelleri, yamaç molozu ve alüvyonlardır. OrtaAnadolu’daki üç baskın fay sistemi bölgenin tektoniğini, havza gelişimini, volkanizmasını ve jeomorfolojisinikontrol etmektedir. Bunlar; Tuzgölü Fay Zonu, Ecemiş Fay Zonu ve Niğde Fayı’dır. Çalışma alanında bulunanNiğde Fayı üzerinde somut jeolojik bilgi elde etmek için, fay hattını dikine kesen iki profil üzerinden elektrikrezistivite profil ve S.P. (Doğal Potansiyel) ölçüm yöntemleri kullanılmıştır. Elektrik rezistivite ve SP verilerinegöre, Niğde Fayı KB-GD doğrultulu, birbirine yaklaşık paralel en az üç muhtemel segmentten oluşan bir fayzonudur. Niğde Masifi’nin kuzeybatı kenarı, Orta Miyosen-Erken Pliyosen zamanında GD yönünde gerileyen faysarplığıdır. Masifin KB tarafındaki kalın yamaç molozunun varlığı bu fikri desteklemektedir.Öğe NİĞDE VOLKANİK KOMPLEKSİ’NİN BATI KESİMİNİN JEOLOJİSİ VE VOLKANOSTRATİGRAFİSİ (KAPADOKYA, ORTA ANADOLU): KEÇİBOYDURAN DAĞI VE YAKIN ÇEVRESİ(2018) Sönmez, Mustafa; Aydın, Faruk; Lermi, Abdurrahman; Saka, Simge OğuzKeçiboyduran Stratovolkanı ve yakın çevresindeki monojenetik koniler, Kapadokya Bölgesi’nin (Orta Anadolu)güneyindeki Niğde Volkanik Kompleksi (NVK) içinde yer alırlar. Stratovolkan’a ait birimler iki evrede oluşan volkanikürünlerle temsil edilir. Birinci evre; yer yer volkanik breş ve tüf seviyeleri içeren piroklastik yayılma çökelleri ile başlarve bunların üzerine amfibolce zengin, piroksenli, andezitik-dasitik bileşimli lav akıntıları gelir. İlk evre, blok ve külakmaları içeren piroklastik akma çökelleri ile sona erer. İlk evrenin amfibollü dasitlerinden elde edilen 40Ar/39Ar yaşları(2.21±0.06 My), bu evrenin erken Alt Pleyistosen’de oluştuğunu gösterir. İkinci evre; piroksence daha zengin, fakatamfibol içermeyen andezitik-dasitik bileşimli lav ürünleri ile başlar ve bunların üzerine iki seviyeden oluşan piroklastikakma çökelleri gelir. Yığın akma çökelleri bu evrenin son ürünleridir. İkinci evrenin andezit ve ignimbritlerinden eldeedilen 40Ar/39Ar yaşları (sırasıyla 1.63±0.02 My ve 1.26±0.18 My), bu ürünlerin geç Alt Pleyistosen’de oluştuğunugösterir. Asidik bileşimli Hasandağı Volkanitleri, akma yapılı, biyotitçe zengin riyolitlerle (0.53-0.45±0.04My) başlarve pümisce zengin kül yağış ve türbülans çökelleriyle (0.44-0.34±0.05 My) sona erer. Orta Pleyistosen’de aktif olan buasidik volkanizmaya eşlik eden Karataş Volkanitleri, olivin-içeren bazaltik lav akıntıları (0.65-0.22±0.02My) vestromboli-tip cüruf yağış ve türbülans çökellerinden oluşmaktadır.Öğe Ore Mineral Textures of Late Cretaceous Volcanogenic Massive Sulfide Deposits of Turkey: Proposed Paragenetic Sequence(SPRINGER INT PUBLISHING AG, 2015) Ciftci, Emin; Lermi, Abdurrahman; Yalcinalp, Bulent; Dong, FMost of the massive sulfide deposits (VMS) occurring from Precambrian to Cenozoic throughout the world have been subsequently metamorphosed at various grades. Thus, all the original textures have been either completely destroyed or strongly modified. However, there are a very few examples, rather younger deposits such as late Cretaceous Turkish VMS deposits and Miocene Kuroko deposits of Japan in which representative and original ore textures are preserved. The Turkish massive sulfide deposits are mainly Cu-Zn-Pb type and entirely hosted by Late Cretaceous felsic volcanic rocks within a paleoarc geotectonic setting. Major ore minerals are base metal sulfides (pyrite, chalcopyrite, bornite, chalcocite, covellite, sphalerite, and galena) and sulfosalts along with quartz, barite, and calcite gangue. In general, dissemination and veinlet textures are extremely abundant in the stockwork and siliceous ore zones that mainly form the base of the massive ore bodies and around the vent through which the ore-forming fluids traversed. In the massive ore, particularly in the central zone of the lenses, fine-grained massive sulfide minerals show a wide variety of replacement and colloform textures. In the lateral zones, clastic or fragmental ore textures may be present if the deposit has undergone a slumping. In the case of cone-shaped deposits, the brecciated ore textures tend to be dominant in the central part of the lens. Most of the minerals are very fine grained, and the larger grains of the major minerals are in the order of 100-300 mu m in size, but most of the minor and trace minerals are much smaller, typically in the order of 1-20 mu m in across. Most of the minerals are anhedral with the exception of pyrite, quartz, and barite that commonly occur as euhedral to subhedral crystals. Four major mineralization stages have been determined at the regional scale. First-stage minerals are two generations of pyrite and chalcopyrite followed by the second-stage minerals including sphalerite, galena, and sulfosalts (mainly tennantite and subordinate tetrahedrite). In the third stage, second generation of chalcopyrite occurs replacing all the earlier phases. This stage is absent in black ore dominating deposits. Bornite prevails in the last stage (aka supergene enrichment) along with chalcocite and covellite, which replaces all the other phases including gangue minerals.Öğe Pollution and probabilistic human health risk assessment of potentially toxic elements in the soil-water-plant system in the Bolkar mining district, Nigde, south-central Turkey(Springer Heidelberg, 2023) Lermi, Abdurrahman; Sunkari, Emmanuel DaanobaGlobally, potentially toxic elements (PTEs) are regarded as an important group of pollutants for the wider environment because of their intrinsic toxicity and probable accumulation in the soil-water-plant system. In this regard, this study assessed the pollution levels and probable human health risks of PTEs in the soil-water-plant system in the Bolkar mining district of the Nigde Province in south-central Turkey. Pollution assessment using contamination factor, enrichment factor, index of geoaccumulation, and soil pollution index reveals moderate to extremely high pollution of PTEs in the soil, exposing the soils to extreme toxicity levels. The areas that fall under the toxic to extremely toxic categories are in proximity to the ore slags and agricultural lands towards the central and southern domains of the study area. The water hazard index (WHI) values indicate that 100% of the samples collected in both winter and fall seasons are of extreme toxicity (WHI > 15). Arsenic is the dominant contaminant among the PTEs in the soil and water samples. The bioconcentration factor values of the PTEs in most of the fruit plants are > 1, indicating very high levels of element transfer from the soil and water to the plants. The probabilistic human health risk assessment involved exposure to arsenic in groundwater (a major pathway to humans) since it is the only carcinogenic element in this study. The estimated daily intake of arsenic-contaminated water exceeds the safe limit of 5 x 10(-8) mg/kg/day. About 33.3% and 55.6% of the groundwater samples have higher hazard quotient and carcinogenic risk values of arsenic in the winter and fall seasons, respectively. This implies that the people are more exposed to the carcinogenic effects of drinking arsenic-contaminated water.Öğe POLLUTION EVALUATION OF HEAVY METALS IN SEDIMENTS FROM THE CAKIT STREAM, ULUKISLA (NIGDE), TURKEY(STEF92 TECHNOLOGY LTD, 2016) Lermi, AbdurrahmanThe aim of this study is to investigate the sediments in Cakit Stream and headwaters, which originate Bolkar Mountains and flow through Central Tauride belt to Mediterranean Sea. Samples were characterized by multivariate statistical analysis to determine the enrichment characteristics of heavy metals as well as their potential risks of pollution. Results showed that the average concentrations of some heavy metals comply with the concentration ranges recommended by the National Standard of Turkey, while the maximum concentrations of Pb, Zn, Ag, Sb and As exceeded these standards. Results from multivariate statistical analysis indicated that Cu, Ni, Cr, and Co originated from natural geological background, while Pb, Zn, Ag, As and Cd in the sediments created from anthropogenic in origin. On the other hand, enrichment factor analysis and the geo-accumulation index evaluation showed that Pb, Zn, As and Pb were existing in the sediments of the river at low or restricted serious pollution, while Cr, Ni, Cu and Co occurred at low pollution levels.Öğe Quaternary bimodal volcanism in the Nigde Volcanic Complex (Cappadocia, central Anatolia, Turkey): age, petrogenesis and geodynamic implications(SPRINGER, 2014) Aydin, Faruk; Schmitt, Axel K.; Siebel, Wolfgang; Sonmez, Mustafa; Ersoy, Yalcin; Lermi, Abdurrahman; Duncan, RobertThe late Neogene to Quaternary Cappadocian Volcanic Province (CVP) in central Anatolia is one of the most impressive volcanic fields of Turkey because of its extent and spectacular erosionally sculptured landscape. The late Neogene evolution of the CVP started with the eruption of extensive andesitic-dacitic lavas and ignimbrites with minor basaltic lavas. This stage was followed by Quaternary bimodal volcanism. Here, we present geochemical, isotopic (Sr-Nd-Pb and delta O-18 isotopes) and geochronological (U-Pb zircon and Ar-Ar amphibole and whole-rock ages) data for bimodal volcanic rocks of the Ni g de Volcanic Complex (NVC) in the western part of the CVP to determine mantle melting dynamics and magmatic processes within the overlying continental crust during the Quaternary. Geochronological data suggest that the bimodal volcanic activity in the study area occurred between ca. 1.1 and ca. 0.2 Ma (Pleistocene) and comprises (1) mafic lavas consisting of basalts, trachybasalts, basaltic andesites and scoria lapilli fallout deposits with mainly basaltic composition, (2) felsic lavas consisting of mostly rhyolites and pumice lapilli fall-out and surge deposits with dacitic to rhyolitic composition. The most mafic sample is basalt from a monogenetic cone, which is characterized by Sr-87/Sr-86 = 0.7038, Nd-143/Nd-144 = 0.5128, Pb-206/Pb-204 = 18.80, Pb-207/Pb-204 = 15.60 and Pb-208/Pb-204 = 38.68, suggesting a moderately depleted signature of the mantle source. Felsic volcanic rocks define a narrow range of Nd-143/Nd-144 isotope ratios (0.5126-0.5128) and are homogeneous in Pb isotope composition (Pb-206/Pb-204 = 18.84-18.87, Pb-207/Pb-204 = 15.64-15.67 and Pb-208/Pb-204 = 38.93-38.99). Sr-87/Sr-86 isotopic compositions of mafic (0.7038-0.7053) and felsic (0.7040-0.7052) samples are similar, reflecting a common mantle source. The felsic rocks have relatively low zircon delta O-18 values (5.6 +/- 0.6 %) overlapping mantle values (5.3 +/- 0.3 %), consistent with an origin by fractional crystallization from a mafic melt with very minor continental crustal contamination. The geochronological and geochemical data suggest that mafic and felsic volcanic rocks of the NVC are genetically closely related to each other. Mafic rocks show a positive trend between Sr-87/Sr-86 and Th, suggesting simultaneous assimilation and fractional crystallization, whereas the felsic rocks are characterized by a flat or slightly negative variation. High Sr-87/Sr-86 gneisses are a potential crustal contaminant of the mafic magmas, but the comparatively low and invariant Sr-87/Sr-86 in the felsic volcanics suggests that these evolved dominantly by fractional crystallization. Mantle-derived basaltic melts, which experienced low degree of crustal assimilation, are proposed to be the parent melt of the felsic volcanics. Geochronological and geochemical results combined with regional geological and geophysical data suggest that bimodal volcanism of the NVC and the CVP, in general, developed in a post-collisional extensional tectonic regime that is caused by ascending asthenosphere, which played a key role during magma genesis.Öğe Slab break-off-related magnesian andesites and dacites with adakitic affinity from the early Quaternary Keciboyduran stratovolcano, Cappadocia province, central Turkey: evidence for slab/sediment melt-mantle interaction and magma mixing(Springer, 2022) Aydin, Faruk; Sonmez, Mustafa; Siebel, Wolfgang; Karsli, Orhan; Lermi, AbdurrahmanVoluminous moderate- to high-magnesian [Mg# = molar Mg/(Mg- + Fe2+) = 44-64] andesitic and dacitic rocks with high silica (mostly 61-66 wt%) adakitic affinity (Y = 13-22, Yb = 1.3-2.1, Sr/Y = 18-44, La/Yb = 10-25) and common mafic magmatic enclaves (MMEs) are first reported in the Keciboyduran stratovolcano (KSV) from the Cappadocia volcanic province (CVP), Central Anatolia, Turkey. We present comprehensive whole-rock geochemistry and Sr-Nd-Pb isotope data, mineral chemical compositions and 40Ar-39Ar ages for KSV samples. Based on the volcanostratigraphy and 40Ar-39Ar dating results, two successive eruption ages of 2.2-1.6 Ma (stage I: amphibole-rich) and 1.6-1.2 Ma (stage II: pyroxene-rich) were established for the KSV, corresponding to the Gelasian and Calabrian stages of Early Pleistocene, respectively. Textural and geochemical evidence indicates that the KSV magnesian andesites-dacites are products of a hybrid magma formed by mixing between mantle-derived mafic and crust-derived felsic magmas with further fractionation and minor contamination during magma storage and ascent. Our new data, combined with previous geological and geophysical results suggest that parental magnesian mafic melts of the KSV rocks originated from a heterogenous mantle source generated through the metasomatism of mantle wedge material by subducted sediment-derived melts, and then partially melted through asthenospheric upwelling in response to slab break-off. The mafic magma underplated the overlying lower crust, resulting in its partial melting to generate crustal felsic magma. Both magmas mixed at lower crustal levels creating MME-rich hybrid magmas. Subsequently, the hybrid magmas were emplaced at different depths of the crust (c. 4-11 and 11-15 km for the stage I and II, respectively), where they crystallized at moderate temperatures (c. 1180-840 degrees C) and under relatively high oxygen fugacity (LogfO(2) = - 11.4 to - 9.2), water-rich (H2Omelt = 5.6-3.6 wt%) and polybaric (similar to 1.2 to 5.1 kbars) conditions, and underwent fractionation of primarily amphibole +/- pyroxene causing adakitic affinity. We propose a new petrogenetic model for the early Quaternary magnesian/adakitic andesites/dacites of the CVP in a post-subduction tectonic setting. Our results provide robust evidence for slab break-off of the eastern Cyprus oceanic lithosphere and put further constraints on the tectonic evolution of the eastern Mediterranean collision zone during the Early Quaternary.Öğe TEPEKÖY VOLKANİTLERİNDE GÖZLENEN HİDROTERMAL ALTERASYONUN MİNERALOJİSİ, JEOKİMYASI VE EKONOMİK POTANSİYELİ, NİĞDE, ORTA ANADOLU, TÜRKİYE(2018) Lermi, Abdurrahman; Sönmez, Mustafa; Aydın, FarukTepeköy civarında andezit, bazalt ve bunların piroklastik çökelleri yaygın olarak gözlenir. Volkanik kayaçlarbaskın olarak andezitik, nadiren de bazaltik bileşimlidir. Hidrotermal alterasyon volkan çıkış merkezi yakın civarıve fay zonlarına bağlı olarak gelişmiştir. Kuvars, serizit, klorit, kaolen, jarosit, alunit, natroalunit, hematit velimonit mineralleri yaygın olan alterasyon mineralleridir. Jeokimyasal analiz ( XRF ve ICP-MS) sonuçlarına göre,bölgede yüzeyleyen volkanik kayaçlar orta-yüksek potasyum içerikli olup, kalk-alkalen karakterlidirler. Kütle venet kütle değişim hesapları, başlıca K (9,93 g), P (0,46 g), Mg (16,74 g), kısmen Al, S az miktarda Si (5,89 g) vecevher oluşturan elementlerin ilavesine bağlı olarak yan kayaçlarda % 25.20’lık net bir kütle artışını göstermiştir.Fay ve kırık zonlarında aşırı derecede kaolenleşme, silisleşme, alunit/jarosit gibi sülfat minerallerinin varlığıbölgede hidrotermal bir sistemin çalıştığını işaret etmektedir. Ayrıca, Ba, Sr, Pb, Bi ve As gibi metallerin aşırıaltere zonlarda zenginleşmiş olmaları, hidrotermal bir sistemin varlığını destekler niteliktedir. Diğer yandansistem, bölgede kalitesini olumsuz yönde etkileyen yüksek silis, hematit-limonit gibi demir mineralleri ve jarositalunit gibi sülfat mineralleri içermelerine karşın ekonomik potansiyele sahip olabilecek kil yataklarının oluşumunusağlamıştır.Öğe The relationship of soils developed on different parent materials in Nigde province with lithological units and determination of their suitability for usage agricultural purposes(Maden Tetkik Ve Arama Genel Mudurlugu-Mta, 2020) Torunlar, Harun; Lermi, Abdurrahman; Ciftci, EminIn this study, general characteristics of soils formed on different parent materials in three different regions of Nigde province, their relationship with lithological units and the extent to which they are suitable for agricultural purposes were determined. Physical and chemical analysis values of rock and soil samples were used to reveal the relationship between lithological units and soils formed in the study area and correlation analysis was applied among the parameters. Multi Criteria Decision Making method was used to determine the suitability of these soils which are formed depending on the parent materials for agricultural use. In order to determine the effect rates among the main criteria of soil, topography, climate and geology and their sub criteria, Analytical Hierarchy Process of Multi Criteria Decision Making method was applied. According to this; Depending on the influence of the lithological units, the soils developed around Bor district are of basic character and the soils developed in ciftlik and Golctik districts and their vicinity are more acidic reaction. In addition, it has been determined that the soils of the ciftlik district and its vicinity are developed by accumulation and in situ, while the soils around Golctik and Bor districts are developed in situ. In determining the suitability of soils for agricultural use, it was calculated that the main criteria of geology was 5.5% and the criteria of lithological units, which is the sub-criterion of this, was 2.7% effective.
