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    Electron paramagnetic resonance of organic and inorganic centers in gamma-irradiated natural sepiolite minerals
    (VERLAG Z NATURFORSCH, 2006) Koseoglu, Rahmi; Koksal, Fevzi; Akkurt, Mehmet; Ciftci, Emin
    Natural sepiolite minerals and their gamma-irradiated forms were investigated by electron paramagnetic resonance (EPR) at room temperature and at 113 K. The EPR signals in powders of natural sepiolite were observed due to clusters of Fe(3+) ions. The paramagnetic centers produced by gamma-irradiation of natural sepiolite minerals were attributed to the CH(3) at room temperature and SO(2)(-) and SO(3)(-) radicals at 113 K. These centers were found to be perfectly observable above 20 mW microwave power. The g values of all paramagnetic centers have been measured and the A values of some of them have been reported. The results were consistent with the literature data for similar paramagnetic centers.
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    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, Emin
    This 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.
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    Geochemical and mineralogical alterations associated with the hostrocks of the kankoy volcanogenic massive sulfide (VMS) deposit (Trabzon, ne-Turkey)
    (2013) Lermi, Abdurrahman; Ciftci, Emin
    This 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.
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    Mineralogy of the Lahanos Deposit a Kuroko-Type Volcanogenic Massive Sulfide Deposit from the Eastern Pontides (Giresun-NE Turkey)
    (Tmmob Jeoloji Muhendisleri Odasi, 2005) Ciftci, Emin; Hagni, Richard D.
    The Lahanos volcanogenic massive sulfide (VMS) deposit is situated in the westernpart of the eastern Pontide tectonic belt. The deposit is hosted predominantly by a late Cretaceous felsic volcanic complex and is mined mainly for copper and zinc. The deposit is essentially stratabound, with characteristics of both Cu-Zn-and Cu-Zn-Pb-type stratiform VMS deposits. The deposit consists mainly of yellov ore (oko) and a zone that can be considered as semi-blackore. Ore mineralization occurs mainly as massive ore, and to lesser extent as disseminated andstochvork ore. Major ore minerals include pyrite, chalcopyrite, sphalerite, galena, tetrahedrite/tennantite, bornite, and minor to trace covellite, marcasite, chalcocite, and digenite. Gangue minerals are chiefly auartz and barite with minor calcite and dolomite. The deposit has aparagenetic seguence of pyrite (I, II) - chalcopyrite (I) sphalerite -galena tetrahedrite/tennantite digenite chalcosite pyrite (III) - chalcopyrite (II) bornite covellite. A great variety of intimate intergrowth ore textures including replacement, colloform, disseminated, and fragmental textures prevail throughout the deposit. The fine-grained nature of the Lahanos ore presents difficulties in beneficiation. Sphalerite, as in other VMS deposits of the region, is notably Fe-poor (< 0. 7 wt. %).
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    Natrolitite, an unusual rock - Occurrence and petrographic and geochemical characteristics (eastern Turkey)
    (CLAY MINERALS SOC, 2008) Ciftci, Emin; Hogan, John P.; Kolayli, Hasan; Cadirli, Emin
    Very unusual rocks consisting of natrolite (>95 vol.%) pargasite (<5 vol.%) and rare albite (<1 vol. %) have been discovered in the Kop mountain range, eastern Turkey. We propose to call these rocks 'natrolitite' and 'pargasite natrolitite'. They were produced by Na Si metasomatism of dikes and stocks of diorite through replacement of the intermediate primary igneous plagioclase to produce natrolite. The metasomatic alteration produced concentric elliptical zones characterized by distinct mineral assemblages centered on intrusions of diorite. The Central Zone 1 consists of variably albitized diorite with preserved magmatic textures (albite +/- andesine +/- pargasite +/- quartz). Transition Zone 2 comprises natrolite-bearing diorite (natrolite +/- albite +/- andesine +/- pargasite +/- calcite +/- quartz). Marginal Zone 3 is a rock made up almost entirely of natrolite (natrolite +/- pargasite +/- albite +/- calcite +/- chlorite). Outer Zone 4 occurs along the boundary between the natrolitite and the surrounding serpentinite and consists of listvenite, a rock which comprises magnesite, quartz, calcite, mica, tale, and hematite, indicating a role for CO2 in the metasomatic reactions, consistent with the presence of calcite in the alteration zones. Zone 5 consists essentially of brecciated serpentinite with numerous hydrothermal quartz veins and calcite veins. Whole-rock compositions document an increase in Na2O, Al2O3, and H2O from the core (central zone) to the margin while CaO, MgO, and SiO2 decrease. Plagioclase abundance and composition also varies outwards from the central core rocks where it occurs as a primary magmatic phase (similar to 95 vol.% An(41-38)) to the alteration zones (<5 vol.% An(32-37)) due to partial to complete replacement of plagioclase by natrolite with or without rare albite. The natrolites exhibit little variation in Si/Al ratios, ranging between 1.45 and 1.61, and are similar in composition to those reported in the literature. Accompanying pargasitic amphibole also becomes progressively more sodic in composition from the core rocks to the marginal zone rocks. Our analysis indicates that albitization preceded the formation of natrolite and that the formation of natrolite, instead of other more typical alteration minerals (e.g. analcime and paragonite), reflects Na metasomatism at lower chemical potentials for Al2O3 and SiO2. Potential sources of Na could be hypersaline brines or leaching of country rocks, such as trondhjemites. The fluids were driven in hydrothermal convection cells set up by the intrusion of the diorites.
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    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, F
    Most 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.
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    Sedimentological characteristics of the Cukurbag formation deposited along the Ecemis Fault Zone, Central Anatolia, Turkey
    (SPRINGER INDIA, 2007) Guerel, Ali; Ciftci, Emin; Kerey, I. Erdal
    The Oligocene Cukurbag Formation, deposited within a long narrow basin surrounded by the Aladag, Ulukisla, and Nigde metamorphic Groups, consists of conglomerate, sandstone, siltstone, mudstone, marl, mudstone-gypsum successions. A number of analytical methods including morphological, mineralogical, and chemical techniques were employed to investigate the sedimentological characteristics of the formation. According to the grain size analyses, sediments of the formation are very poorly sorted with strong positive to near symmetrical skewness. The analyses show that irregular flow regime should have occurred during sedimentation of the 1;ukurbag Formation. These sediments comprises mainly of quartz, feldspars, calcite, clinopyroxene, and Fe-oxides. Common clay minerals include smectite, chlorite, and kaolinite. The chemical analyses carried out on the samples representing the bottom to the top of the formation indicated that SiO2, Al2O3, K2O, and P2O5 contents are low compared to the world mudstone averages. However, MgO, CaO, and C contents are comparatively high. Four measured profiles showing the distribution of principle facies within the formation are prepared. Based on the profile analyses, seven distinct lithological facies were distinguished that include massive conglomerate, bedded conglomerate, stratified sandstone, cross-bedded sandstone, laminated siltstone, massive mudstone-marl, and laminated mudstone-gypsum. This study suggests that the sediments of this formation must have been reworked material transported from unknown distances and deposited in an alluvial fan-braided stream and lacustrine environments.
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    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, Emin
    In 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.