Yazar "Bozkaya, Omer" seçeneğine göre listele
Listeleniyor 1 - 20 / 27
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Alteration Mineralogy and Geochemistry of the rocks from Tekirova (Antalya) Ophiolite Nappe(TMMOB JEOLOJI MUHENDISLERI ODASI, 2015) Yalcin, Huseyin; Bozkaya, Omer; Yilmaz, CananThe Tekirova Ophiolite Nappe, part of the Antalya Unit in the southwest Anatolia, consists of a dismembered oceanic crust sequence with tectonic slices in different sizes. Three types of subsequent mineralizations are present in the ophiolitic rocks during the oceanic crust formation, emplacement and post-emplacement, respectively. First stage, pyrometamorphism (pyrometasomatization) caused to occurrence of metamorphic minerals such as scapolite, diopside, garnet, epidote and tremolite. Second stage, hydrothermal metamorphism(alteration) is represented byserpentinization of ultramafic rocks. Third stage is followed by listwaenite formation, and age neoformation and/or alteration products contain carbonates (calcite, dolomite, aragonite, magnesite, hydromagnesite, hydrotalcite), oxides and hydroxides (brucite, goethite, hematite), phyllosilicates (smectite, illite, chlorite, talc, C-V, C-S, I-S) and quartz. The serpentine minerals can be distinguished from each other by morphology: ribbon-like shapes for antigorite, platy for lizardite and fibrous for chrysotile. Serpentines are represented by three polytypes as structural groups of A- (clinochrysotile-2M(1)), C- (lizardite-1T) and D- (lizardite-2H(1)). Chondrite-normalized trace and rare earth element patterns of 1T and 2H(1) Fe-lizardites, Fe-tremolite and Ca-hydromagnesite minerals show similar trends indicating similar ophioliticparent rocks and differentiated form each others. The delta O-18 and delta D values of serpentines indicate two different serpantinization under hypogene conditions as oceanic (lizardite-1T) and supergene as Alpin types (clinochrysotile-2M(1) and lizardite-2H(1)) at temperatures of about 200 degrees C and 100 degrees C, respectively.Öğe Approaches to the Low Grade Metamorphic History of the Karakaya Complex by Chlorite Mineralogy and Geochemistry(MDPI AG, 2015) Tetiker, Sema; Yalcin, Huseyin; Bozkaya, OmerIn this study, chlorite is used to investigate the diagenetic-metamorphic evolution and accurate geological history of the different units belonging to the Karakaya complex, Turkey. Primary and secondary chlorite minerals in the very low-grade metamorphic rocks display interference colors of blue and brown and an appearance of optical isotropy. Chlorites are present in the matrix, pores, and/or rocks units as platy/flaky and partly radial forms. X-ray diffraction (XRD) data indicate that Mg-Fe chlorites with entirely IIb polytype (trioctahedral) exhibit a variety of compositions, such as brunsvigite-diabantite-chamosite. The major element contents and structural formulas of chlorite also suggest these were derived from both felsic and metabasic source rocks. Trace and rare earth element (REE) concentrations of chlorites increase with increasing grade of metamorphism, and these geochemical changes can be related to the tectonic structures, formational mechanics, and environments present during their generation.Öğe Approaches to the Low-Grade Metamorphic History of the Karakaya Complex by Chlorite Mineralogy and Geochemistry(TMMOB JEOLOJI MUHENDISLERI ODASI, 2015) Tetiker, Sema; Yalcin, Huseyin; Bozkaya, OmerChlorite minerals are commonly found in the units of Karakaya Complex that reflect different tectonic settings and evolution. In this study, the availability of chlorites has been investigated as a parameter on the interpretation of the diagenetic-metamorphic evolution and revealing the geological history from the different units of the complex. Primary and secondary chlorite minerals in the low-very low-grade metamorphic rocks have interference colors of blue and brown and an optical isotropic appearance with very low birefringence. Chlorites are seen in the matrix, pores and/or pods of rocks as platy/flaky and partly radial forms. According to X-ray diffraction (XRD) data; Mg-Fe chlorites with entirely IIb polytype (trioctahedral) exhibit various compositions such as brunsvigite-diabantite-chamosite. Furthermore, chlorite minerals correspond to felsic and metabasic origins in terms of the rocks from which they derived. Similarly, geochemical data such as the major element contents and structural formulas of chlorites also suggest a different composition and origin. Trace and especially rare earth element (REE) concentrations of chlorite minerals increase from schist towards slate depending on their degree of metamorphism and nature of the host rocks. This relationship can be significantly noticed in the chondrite-normalized REE and trace element patterns. These changes show that are they are related to the structures, formation mechanisms and tectonic environments of the chlorite minerals. In other words, they suggest that chlorites may play a key role in distinguishing of units with different geological history.Öğe Clay mineralogy of the Paleozoic-Lower Mesozoic sedimentary sequence from the northern part of the Arabian Platform, Hazro (Diyarbakir, Southeast Anatolia)(SLOVAK ACAD SCIENCES GEOLOGICAL INST, 2011) Bozkaya, Omer; Yalcin, Huseyin; Kozlu, HuseyinThe Paleozoic-Lower Mesozoic units in the Diyarbakir-Hazro region consist of sandstone (subarkose, quartz arenite), mudstone, shale, coal, marl, dolomitic marl, limestone (biomicrite, lithobiosparite, biosparite with lithoclast, dololithobiosparite, dolomitic cherty sparite) and dolomite (dolosparite, dolosparite with lithoclast, biodolosparite with glauconite). These units exhibit no slaty cleavage although they are oriented parallel to bedding planes. The sedimentary rocks contain mainly calcite, dolomite, quartz, feldspar, goethite and phyllosilicates (kaolinite, illite-smectite (I-S), illite and glauconite) associated with small amounts of gypsum, jarosite, hematite and gibbsite. The amounts of quartz and feldspar in the Silurian-Devonian units and of dolomite in the Permian-Triassic units increase. Kaolinite is more commonly observed in the Silurian-Devonian and Permian units, whereas illite and 1-S are found mostly in the Middle Devonian and Triassic units. Vertical distributions of clay minerals depend on lithological differences rather than diagenetic/metamorphic grade. Authigenetic kaolinites as pseudo-hexagonal bouquets and glauconite and I-S as fine-grained flakes or filaments are more abundantly present in the levels of elastic and carbonate rocks. Illite quantities in R3 and RI 1-S vary between 80 and 95 %. 2M(1)+1M(d) illites/1-S are characterized by moderate h cell values (9.005-9.040, mean 9.020 angstrom), whereas glauconites have higher values in the range of 9.054-9.072, mean 9.066 angstrom. KI values of illites (0.72-1.56, mean 1.03 Delta 2 theta degrees) show no an important vertical difference. Inorganic (mineral assemblages, KI, polytype) and organic maturation (vitrinite reflection) parameters in the Paleozoic-Triassic units agree with each others in majority that show high-grade diagenesis and catagenesis (light petroleum-wet gas hydrocarbon zone), respectively. The Paleozoic-Triassic sequence in this region was deposited in the environment of a passive continental margin and entirely resembles the Eastern Taurus Para-Autochthon Unit (Geyikdagi Unit) in respect of lithology and diagenetic grade.Öğe Diagenesis/Metamorphism History of Lower Triassic Cigli Group Rocks in Uludere-Uzungecit (Sirnak) area (Eastern Part of the Southeast Anatolian Autochthone)(TMMOB JEOLOJI MUHENDISLERI ODASI, 2016) Tetiker, Sema; Yalcin, Huseyin; Bozkaya, OmerThis study aims to reveal the mineralogical characteristics of the carbonate and pelitic rocks in the Lower Triassic Cigli Group in the Uludere-Uzungecit (Sirnak) region from Southeast Anatolian Autochthone (SEAA). Cigli Group is represented by Yoncali Formation (dolomite-siltstone-shale with limestone intercalation), Uludere Formation (shale/shale with carbonate-clayey limestone intercalated with dolomite) and Uzungecit Formation (limestone with chert nodule-dolomitic limestone-shale) from bottom to top. In order of abundances of minerals obtained by XRD investigations as follows; Yoncali Formation contains carbonate (calcite, dolomite), feldspar, phyllosilicate (illite, chlorite) and goethite minerals, and Uludere Formation is made up of carbonate (calcite, dolomite), quartz, feldspar, phyllosilicate (illite, chlorite, mixed-layered chlorite-vermiculite/C-V, and very minor amount of kaolinite in only a sample) and hematite minerals. Uzungecit Formation has carbonate (dolomite, calcite), silica (quartz, opal-CT, moganite), phyllosilicate (chlorite, illite), and feldspar and hematite minerals. On the basis of illit Kubler Index values; Yoncali Formation reflects the degrees of anchizone; as for Uludere and Uzungecit formations, they have the degrees of anchizone-high diagenesis, respectively. Similarly, Chlorite Arkai Index (AI, degrees 2 theta) values indicate the grades of anchizone-diagenesis. Illites exhibit 2M(1) ve 2M(1) + 1M + 1M(d) polytypes and the values of b unit-cell distances show a composition close to ideal muscovite and low pressure conditions. The rocks of the Cigli Group offer differences in terms of rare occurrence of kaolinite, appearance of moganite and C-V and the dominance of dolomite and hematite in most levels, and diagenesis/metamorphism grades are also high, when compared with the equivalent units in the Diyarbakir-Hazro area. Lower Triassic series regionally seem to have a deeper depositional environment, and have relatively higher maturation because of the volcanic feeding and tectonic burial in the Diyarbakir-Sirnak direction from west to east.Öğe Diagenetic and very low-grade metamorphic characteristics of the Paleozoic series of the Istanbul Terrane (NW Turkey)(SPRINGER BASEL AG, 2012) Bozkaya, Omer; Yalcin, Huseyin; Goncuoglu, Mehmet CemalThe Istanbul Terrane along the Black Sea coast in NW Anatolia, is a Gondwana-derived continental microplate, comprising a well-developed Paleozoic succession. Petrographic and X-ray diffraction studies were performed on rock samples from measured sections throughout Ordovician-Carboniferous sedimentary units. Diagenetic-very low-grade metamorphic clastic (shale/mudstone, siltstone, sandstone) and calcareous rocks (limestone, dolomite) mainly contain phyllosilicates, quartz, feldspar, calcite, dolomite, hematite and goethite minerals. Phyllosilicates are primarily represented by illite, chlorite, mixed-layered chlorite-vermiculite (C-V), chlorite-smectite (C-S) and illite-chlorite (I-C). Feldspar is commonly present in the Ordovician and Carboniferous units, whereas calcite and dolomite are abundant in the Silurian and Devonian sediments. The most important phyllosilicate assemblage is illite + chlorite + I-C + C-V + C-S. Illite and chlorite-bearing mixed layer clays are found in all units. The amounts of illites increase in the upper parts of the Silurian series and the lower parts of the Devonian series, whereas chlorite and chlorite-bearing mixed-layers are dominant in the Ordovician and Carboniferous units. Kubler index values of illites reflect high-grade anchimetamorphism for the Early Ordovician rocks, low-grade metamorphism to high-grade diagenesis for the Middle Ordovician-Early Silurian rocks and high-grade diagenesis for the Late Silurian-Devonian units. The K-white micas b cell dimensions indicate intermediate pressure conditions in the Early Ordovician-Early Silurian units, but lower pressure conditions in the Middle Silurian-Devonian units. Illites are composed of 2M(1) +/- 1M(d) polytypes in all units, except for Upper Ordovician-Lower Silurian units which involve 1M polytype in addition to 2M(1) and 1M(d) polytypes. The 2M(1)/(2M(1) + 1M(d)) ratios rise from Devonian to Ordovician together with the increasing diagenetic-metamorphic grade. Chlorites have IIb polytype. In general, crystal-chemical data of clay minerals in the Istanbul Terrane show a gradual increase in the diagenetic/metamorphic grade together with increasing depth. The new data presented in this work indicate that the diagenetic/metamorphic grade of the Paleozoic of the Istanbul Terrane is higher than that of the neighboring Zonguldak Terrane and generated by a single metamorphic phase developed at the end of Carboniferous. This finding contrasts with the metamorphic history of the neighboring Zonguldak Terrane that displays a distinct Early Devonian unconformity and a thermal event.Öğe Evidence of the diagenetic history of sediment composition in Precambrian-early Paleozoic rocks: a systematic study from the Southeast Anatolian Autochthon, Mardin (Derik-KA +/- zA +/- ltepe), Turkey(SPRINGER HEIDELBERG, 2015) Tetiker, Sema; Yalcin, Huseyin; Bozkaya, OmerThe mineralogical properties of the Precambrian-early Paleozoic series have been investigated in the Southeast Anatolian Autochthon (SEAA) and are represented by generally clayey siliciclastic and rarer volcanogenic rocks. These include basalt, andesite, and volcanic sandstones of the Precambrian period; siliceous sandstone, dolomite, shale, and siltstone of the Cambrian period; and sandy dolomite, shale, siltstone, sandstone, and limestone with red Fe nodules of the Lower-Upper Ordovician period. The rock-forming minerals determined in order of abundance are feldspar, pyroxene, quartz, and olivine in the Precambrian unit; quartz, moganite, calcite, dolomite, feldspar, and phyllosilicates (illite, chlorite, mixed-layered illite-smectite/I-S, smectite) in the Cambrian units; and phyllosilicates (kaolinite, illite, chlorite, I-S, mixed-layered chlorite-vermiculite/C-V, smectite), quartz, feldspar, calcite, dolomite, moganite, and goethite in the Lower-Upper Ordovician units. Short prismatic and partly radiating moganites discovered in the early Paleozoic sediments in Turkey are present between euhedral and coarse-grained quartz and feldspar in the sandstones. Thin platy illites have undergone a transition that introduces a fibrous/thread-like mixed-layer I-S through their edges. The rhombohedral dolomites have dissolution traces associated with siliceous balls, long thin filament-shaped illites, and acicular-radial chlorites. Illites usually show coarse and tiny plates parallel to each other and partly radiating flakes, and chamosite-type chlorites form thick plates in the siliciclastics. Kaolinites consist of typical pseudohexagonal sheets with parallel or accordion-like booklets in the siltstones. The Kubler index indicates low- to high-grade diagenesis to low-grade diagenesis, signifying that the location partially differs from the other units of the SEAA and Taurus Belt. In addition, Paleozoic rocks reflect no maturation characteristics with respect to the petroleum system.Öğe Fluid evolution of mixed base-metal gold mineralization in the Tethys belt: Koru deposit, Turkey(SOC GEOLOGY APPLIED MINERAL DEPOSITS-SGA, 2017) Bozkaya, Gulcan; Bozkaya, Omer; Banks, David A.; Gokce, Ahmet; MercierLangevin, P; Dube, B; Bardoux, M; Ross, PS; Dion, CKoru is one of a number of base-metal gold deposits hosted by Oligo-Miocene volcano-sedimentary rocks of deposits in the Biga peninsula. Barite, quartz and galena are main minerals and are accompanied by minor amounts of sphalerite, pyrite, chalcopyrite, covellite and marcasite. Th of fluid inclusions indicates two distinct fluid pulses, one at high temperature (340 degrees C) commensurate with epithermal mineralization and boiling/near boiling conditions and the second approximately 150 degrees C lower. Salinity in both instances was from 11-0.2 wt. % NaCl. The range of temperatures within individual samples is consistent with variations from near lithostatic to hydrostatic pressure during vein and fracture opening. There are two different ranges of delta S-34 values of H2S in equilibrium with barite (+5.5 to +7.9 parts per thousand) and sulfide minerals (-2.1 to -0.5 parts per thousand), indicating that the sulfur in sulfide minerals and barite derived from different sources; magmatic and seawater respectively.Öğe Geochemical monitoring of clays for diagenetic evolution of the Paleozoic-Lower Mesozoic sequence in the northern Arabian plate: Hazro and Amanos regions, Southeastern Turkey(PERGAMON-ELSEVIER SCIENCE LTD, 2013) Bozkaya, Omer; Yalcin, HilseyinClay minerals in the diagenetic/very low-grade metamorphic-sedimentary series from southeastern Anatolia in Turkey were analyzed to determine their mineralogical and chemical compositions. In the Amanos region, the lowermost unit is composed of metaclastics with primary clastic textures, as well as slaty cleavages and chlorite-mica stacks including volcanic rock intercalations. The Lower Cambrian is composed of mainly very low-grade metamorphic clastic rocks, while the Ordovician units have siliciclastic and carbonate rocks. In the Hazro region, the Late Silurian-Lower Triassic units are represented by highly diagenetic carbonate and clastic rocks. All of the rock units include illite. In addition, chlorite, mixed-layered illite-chlorite and chlorite-vermiculite are present in the Amanos region, while calcite, dolomite, kaolinite, mixed-layered illite-smectite (I-S) and glauconite occur in the Hazro region. The illites are characterized by the dominance of 2M(1) polytype in the Amanos samples; and 1M(d) + 2M(1) in the Hazro samples. The I-S, glauconite and kaolin have R1 and R3, 1M and kaolinite polytypes, respectively. The illites have greater tetrahedral and lower octahedral substitutions than the I-S. Total trace element contents, elemental substitutions and chondrite-normalized trace element and REE values decrease toward illite-I-S-kaolinite. There are obvious fractionations for some major - trace and rare earth elements with respect to each other and clear enrichment with respect to the chondrite, with strong anomalies of positive for Gd and negative for P, K and Eu in the clay minerals. The textural, morphological and geochemical data indicate that kaolinite and I-S in the Hazro area occur in supergene conditions with due to a full neoformation mechanism, whereas illites in the Amanos region represent the hypogene origin. In brief, the K2O contents, ratios of Eu/Eu* and La-N/Lu-N and delta O-18 and delta D values of I-S and illite exhibit notable relationships with increasing diagenetic/metamorphic grade. (C) 2013 Elsevier Ltd. All rights reserved.Öğe Geochemical Properties of Phyllosilicates in Goksun, Afsin and Ekinozu Metamorphites (Kahramanmaras, Turkey)(Tmmob Jeoloji Muhendisleri Odasi, 2021) Hozatlioglu, Deniz; Bozkaya, Omer; Yalcin, HuseyinThis study determined the geochemical properties of phyllosilicates in the Upper Palaeozoic-Lower Mesozoic metamorphic units outcropping from west to east in the vicinities of Goksun, Afsin and Ekinozu towns in the north of Kahramanmaras province in the westerly part of the Eastern Taurus mountains. Geochemical examination of phyllosilicates (major and trace elements, stable isotope) was carried out on pure K-micas and illite/K-micas separated from low-medium grade metamorphic samples. According to the main oxide composition of the phyllosilicates, illite/K-micas from the areas of Afsin and Goksun contain higher SiO2 and Al2O3 and lower MgO, Fe2O3, MnO and Na2O compared to those in the area of Ekinozu. The minerals represented by schists in the Ekinozu K-micas are close to having a biotite-celadonite composition while those with phyllites in Afsin and Ekinozu are close to muscovite composition. Chlorites have a trioctahedral composition between chamosite and clinochlor. Illite/K-micas with both trioctahedral and dioctahedral characteristics show a composition between muscovite and biotite (biotite-celadonite, muscovite-phlogopite, muscovite-ferriphengite, muscovite-ferrobiotite, Al-phlogopite-Alannite) in general. In the trace element content of phyllosilicate minerals, transition metals and granitoid elements are at high concentrations while other elements, especially elements with low (LFSE) and high field strength (HFSE), display low concentrations. In the chondrite-normalized trace element content of phyllosilicate minerals, chlorites have higher values compared to K-micas and trioctahedral K-micas show lower values compared to dioctahedral K-micas. Rare earth element (REE) distribution of chlorite and sericite/K-mica minerals is normalised to chondrite and North American Shale Composition (NASC); the dioctahedral K-mica of Afsin region has the highest depletion, while the trioctahedral mica of Ekinozu has the highest enrichment. The oxygen and hydrogen isotope composition of the phyllosilicate minerals show that they are in the hypogene region, which represents high temperature and deep environment conditions. The oxygen and hydrogen isotope values of sericite/K-mica and chlorites indicate that the formation temperatures of these minerals varied between 375 and 500 degrees C. 40Ar/39Ar radiometric age data for the metamorphic rocks show that the metamorphism developed during the Upper Cretaceous (Santonian-Campanian) in the Afsin and Goksun regions and the Lower-Middle Eocene (Ypresian-Bartonian) periods in the Ekinozu region.Öğe GEOCHEMISTRY OF MIXED-LAYER ILLITE-SMECTITES FROM AN EXTENSIONAL BASIN, ANTALYA UNIT, SOUTHWESTERN TURKEY(CLAY MINERALS SOC, 2010) Bozkaya, Omer; Yalcin, HuseyinThe Antalya Unit, one of the allochthonous units of the Tauride belt, is of critical, regional tectonic importance because of the presence of rifling remnants related to the break-up of the northern margin of Gondwana during Triassic time. Paleozoic-Mesozoic sedimentary rocks of the Antalya Unit consist mainly of calcite, dolomite, quartz, feldspar, and phyllosilicate (illite-smectite, smectite, kaolinite, chlorite, illite, chlorite-smectite, and chlorite-vermiculite) minerals. Illite-smectite (I-S) was found in all of the sequences from Cambrian to Cretaceous, but smectite was only identified in Late Triassic-Cretaceous sediments. R0 I-S occurs exclusively in early-diagenetic Triassic-Cretaceous units of the Alakircay Nappe (rift sediments), whereas R3 I-S is present in late-diagenetic to low-anchimetamorphic Cambrian-Early Triassic units of the Tahtalidag Nappe (pre-rift sediments). Kubler Index (KI) values and the illite content of I-S reflect increasing diagenetic grades along with increasing depth. Major-element, trace-element, rare-earth-element (REE), and stable-isotope (O and H) compositions were investigated in dioctahedral and trioctahedral smectites and I-S samples from the pre-rift and rift-related formations. Both total layer charge and interlayer K increase, whereas tetrahedral Si and interlayer Ca decrease from smectite to R3 I-S. Trace-element and REE concentrations of the I-S are greater in pre-rift sediments than in rift sediments, except for P, Eu, Ni, Cu, Zn, and Bi. On the basis of North American Shale Composite (NASC)-normalized values, the REE patterns of I-S in the pre-rift and rift sediments are clearly separate and distinct. Oxygen (delta O-18) and hydrogen (delta D) values relative to SMOW (Standard Mean Oceanic Water) of smectite and I-S reflect supergene conditions, with decreasing delta O-18 but increasing delta D values with increasing diagenetic grade. Lower delta D values for these I-S samples are characteristic of rift sediments, and pre-rift sediments have greater values. On the basis of isotopic data from these I-S samples, the diagenesis of the Antalya Unit possibly occurred under a high geothermal gradient (> 35 degrees C/km), perhaps originating under typical extensional-basin conditions with high heat flow. The geochemical findings from I-S and smectites were controlled by diagenetic grade and can be used as an additional tool for understanding the basin maturity along with mineralogical data.Öğe Mapping of lithological units in the western part of the Eastern Taurides (Türkiye) using ASTER images(Tubitak Scientific & Technological Research Council Turkey, 2024) Hozatlioglu, Deniz; Bozkaya, Omer; Inal, Sedat; Kavak, Kaan SevkiThe Eastern Taurides, which form the imbrication and nappe zone in the northernmost part of the Arabian platform, are located within the Southeastern Anatolian Orogenic Belt. In the present study, spectral enhancement methods such as band ratioing, minimum noise fraction (MNF), relative band depth (RBD), and supervised classification were applied to ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) images of metamorphic massifs, ophiolites, and sedimentary rocks outcropping in the western part of the Eastern Taurides (Goksun, Afsin, and Ekinozu regions). With these methods, the aim was to distinguish geological units from each other accurately. In the study area, arid climatic conditions with relatively poor vegetation, allowing for precise visual interpretations, play a significant role. Vegetation and water bodies were also masked before these procedures. In the Goksun, Afsin, and Ekinozu regions, metamorphic rocks of phyllite, schist, and gneiss types, which underwent metamorphism during the Upper Cretaceous and Eocene periods, are observed. The geologically dominant minerals in these rocks include silica, mica (muscovite, phengite, biotite), chlorite (clinochlore, chamosite), kaolinite, and carbonates (calcite, dolomite). These rocks are accompanied by ophiolitic, volcanic/ volcano -sedimentary, and plutonic igneous rocks. Due to geological events during the closure of the Neotethys Ocean and continental collision in the area, it became evident that the lithological diversity from various rock groups was reflected in the ASTER images, in addition to field observations. Image processing analyses applied to the ASTER sensor images, rich in short-wave infrared (SWIR) and thermal infrared (TIR) bands on the Terra platform, revealed distributions of clay, sulfate, carbonate, iron oxide, and silica minerals. The highest geological differentiation potential was observed through ASTER 643 (RGB) and ASTER 13,12,10 (RGB) false -color composites, as well as ASTER 456 (RGB) minimum noise fraction (MNF) analyses and, especially, relative band depth processes. Relative band depth processes were employed to identify epidote-chlorite-amphibole, calcite -chlorite -amphibole, alunite-kaolinitepyrophyllite, muscovite, and silica minerals. The application of these processes revealed lithologies that strongly feature these minerals. Specifically, the goal was to differentiate rock units containing kaolinite, muscovite, phengite, chlorite, and epidote minerals belonging to AlOH and FeOH groups and elucidate their compositions. Moreover, rocks containing primarily quartz and feldspar were distinguished using ASTER TIR bands. The obtained data revealed that mineralogical and corresponding lithological spatial distributions, as depicted by ASTER images, could play a crucial role in geological mapping, particularly in regions where mapping is challenging due to geographical conditions.Öğe Metamorphic evolution of the Karakaya Complex in northern Turkey based on phyllosilicate mineralogy(SPRINGER WIEN, 2015) Tetiker, Sema; Yalcin, Huseyin; Bozkaya, Omer; Goncuoglu, M. CemalThe Triassic Karakaya Complex (KC) of the Sakarya Composite Terrane in northern Turkey is traditionally subdivided into two units. The Lower Karakaya Complex (LKC) consists of a tectonic m,lange with blocks of metabasic rocks, metacarbonates, meta-arenites and metapelites that have been affected by high pressure/low temperature metamorphism. It is followed by a low pressure/low temperature metamorphic overprint; the latter is the only metamorphic event in some tectonic slivers of the LKC. The Upper Karakaya Complex (UKC) units are primarily composed of diagenetic to low-grade metamorphic rocks, comprising Late Permian and Triassic cherts and blocks of OIB-type volcanic rocks interfingering with Anisian limestones. LKC slide-blocks of variable sizes are frequently observed within the UKC. Phyllosilicates of LKC and UKC were examined for their abundance, crystallinity, polytype and b cell dimension. Trioctahedral chamositic chlorites have IIb polytype and phengites 2 M (1) polytypes in the LKC units and 2 M (1) + 1 M + 1M (d) polytypes of phengitic dioctahedral illites in the UKC units. Kubler index data correspond to the low anchizone and epizone for the LKC units, and to the high diagenesis-low anchizone, and in part to the epizone for the UKC units. The b values of illites are consistent with a high-pressure facies series for the LKC, but only intermediate-pressure facies for the UKC. According to textural features, mineral paragenesis, clay transformations, index minerals, and b values, the lower-middle parts of the LKC represent an accretional tectonic setting, whereas the UKC units reflect pressure temperature conditions of an extensional basin affected by high heat flow.Öğe Metamorphic-hosted pyrophyllite and dickite occurrences from the hydrous AI-SILICATE deposits of the malatya-puturge region, Central Eastern Anatolia, Turkey(CLAY MINERALS SOC, 2007) Bozkaya, Omer; Yalcin, Huseyn; Basibuyuk, Zeynel; Bozkaya, GolcanHydrous Al-silicate deposits are found to the south of Puturge in Malatya city, Turkey. The surrounding rocks consist of mylonitic granitic gneiss overlain by muscovite gneiss with kyanite-bearing metabasic schist lenses on top which are cut by silica veins containing prismatic tourmaline and specularite. Pyrophyllite is found within kyanite gneisses overlying the granitic gneisses. Fibrous, platy pyrophyllite is developed along the edges and cleavage planes of kyanite, whereas platy bunches of dickite occur as replacements of the relict kyanites as well as crack- and pore-fillings. Rocks forming the hydrous Al-silicate deposit contain 2M(1) pyrophyllite, alunite, topaz, paragonitc, dravite, dumortierite, chlorite and epidote as early hypogene minerals, and 2M(1) dickite, diaspore, gibbsite, specularite, goethite and crandallite/goyazite as late hypogene minerals. On the basis of fluid inclusion and stable isotope data, it is estimated alterations to pyrophyllite and kaolinite occurred at temperatures are of 150 and 100 degrees C, respectively, the minerals being formed by meteoric waters interacting with metamorphic rocks. Trace and REE variations are highly distinctive in terms of enrichment of most trace elements in pyrophyllitc, whereas REEs are clearly abundant in dickite, indicating different conditions during formation such as early and late hypogene processes. The pyrophyllitic alteration took place in the late Cretaceous (69-71 Ma), whereas kaolinization occurred later.Öğe Mineral Chemistry of Chlorite and Illite/Mica in the Clastic Rocks of Karakaya Complex: Origin and Diagenesis/Metamorphism(TMMOB JEOLOJI MUHENDISLERI ODASI, 2018) Bozkaya, Omer; Yalcin, Huseyin; Tetiker, SemaThe Karakaya Complex units representing the relicts of environments related with the closure of PreJurassic Paleotethys Ocean outcrop within the Sakarya Composite Terrane. The compositions of illite/white micas change among muscovite-illite-phengite that illite/white micas with detrital and authigenic origins are close to muscovitic (Si-avg = 3.15, (Na+ K) avg = 0.81) and illitic compositions (Si-avg = 3.22, (Na+K)(avg) = 0.74), respectively. Paragonite (Si-avg = 2.96, Na= 0.78, K= 0.10) and NaK micas (Si-avg = 3.09, Na= 0.45, K= 0.34) are typical for extentional basins that are determined in the upper parts of the Turhal Metamorphites corresponding to the subgreenschist facies of the Karakaya Complex. The chlorites are of entirely trioctahedral and authigenic ones (Si-avg = 5.67, Fe avg = 5.05) have higher SiIVand lower FeVI contents in comparison with detrital ones. Chlorites have chamositic in the Hodul Unit, whereas clinochlore composition in the Orhanlar Unit. Detrital micas with high Mg (5.70-7.59) and Cr (0.09-0.16) contents are also identified in the Orhanlar Unit more common and in the Turhal Metamorphites as a few grains that are evaluated as evidences the presence Pre-Triassique ophiolitic rocks. The data of chlorite chemistry indicate the origins of felsic for Turhal Metamorphites, metabasic (probably remains of Paleotethys) for Orhanlar Unit and felsic and metapelitic with rich in Al and extreme rich in Fe. The data of chlorite geothermometry and phengite geobarometer indicate a temperature ranging from 150 to 300 degrees C and a pressure between 0.5-1.2 kbar, respectively. These values reflect the the high temperature-low pressure metamorphism for the upper part of the Karakaya Complex representing sub-greenschist facies and low-middle temperature-low pressure diagenesis conditions for sub-greenschist facies units of the Karakaya rift.Öğe Mineral Chemistry of Low-Temperature Phyllosilicates in Early Paleozoic Metaclastic Rocks, Eastern Tauride Belt, Turkiye(Mdpi, 2022) Bozkaya, Omer; Yalcin, HuseyinThe mineral chemistry of illite/mica and chlorites, together with the evaluation of textural data of low-temperature metaclastic rocks, plays an important role in determining their origin and metamorphic grade. This study aimed to investigate the chemical properties of phyllosilicates in early Paleozoic metaclastic rocks in the Eastern Tauride Belt, Turkiye. The textural (electron microscopy) and chemical (mineral chemistry analysis) analyses were performed on the samples representing different grades of metamorphism. The illites/micas and chlorites are observed as detrital (chlorite-mica stacks) and neoformation origin. Trioctahedral chlorites (chamosite) exhibit different chemistry for detrital and neoformed origin as well as the metamorphic grade. Tetrahedral Al and octahedral Fe + Mg increase, whereas octahedral Al decreases together with the increasing grade of metamorphism. The detrital chlorites have higher tetrahedral Al and Fe contents than their neoformed counterparts. Chlorite geothermometry data (detrital: 241->= 350 degrees C; neoformed: 201-268 degrees C) are compatible with the texture and illite Kubler index data. Illite/white-mica compositions display muscovite and Na-K mica. Tetrahedral Al and interlayer K + Na contents of illites/micas increase with metamorphic grade. Na-K mica and paragonite are observed as replacement-type developments within the detrital CMS. The obtained data indicate that phyllosilicate chemistry can be used effectively for determining the geological evolution of low-grade metamorphic sequences.Öğe Mineralogic evidences of a mid-Paleozoic tectono-thermal event in the Zonguldak terrane, northwest Turkey: implications for the dynamics of some Gondwana-derived terranes during the closure of the Rheic Ocean(CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS, 2012) Bozkaya, Omer; Yalcin, Huseyin; Goncuoglu, Mehmet CemalThe Zonguldak terrane is a Gondwana-derived continental microplate along the Black Sea coast in northwest Anatolia. It includes a Cadomian basement, with oceanic-and island-arc sequences, unconformably overlain by siliciclastic rocks of Ordovician to Middle Silurian age. After a period of deformation and erosion, late Lower Devonian (Emsian) quartzites and shallow-marine limestones unconformably cover Middle Silurian (Wenlock) graptolitic shales. Along several cross sections across the unconformity plane, the mineralogical characteristics of the Paleozoic sedimentary rocks in the Zonguldak terrane are studied to check whether this regional unconformity is only of epeirogenic nature or the result of a thermal event. In addition to the appearance of kaolinite in Devonian units, crystal-chemical data of illites show a sudden jump at the unconformity plane. The b cell dimension values of illites of Ordovician-Silurian units are somewhat higher than those of Devonian-Carboniferous units and show a drastic drop between the Silurian and Devonian units. The new mineralogic data indicate that the pre-Emsian rocks in the Zonguldak terrane experienced a thermodynamo event, prior to the Emsian transgression. This Caledonian-time event is also reported in east Moesian terrane but not noticed in the neighboring Istanbul-Zonguldak and in the west Moesian Balkan - Kreishte terranes. By this, it is suggested that Zonguldak and east Moesian terranes behaved independently from the Istanbul-Balkan terranes during the closure of the Rheic Ocean. They very likely docked to Laurussia during Emsian by strike-slip faults and remained thereon at its platform margin, where the Middle-Late Devonian shallow-platform conditions were followed by fluvial (lagoon and delta) conditions and deposition of coal during Late Carboniferous.Öğe Mineralogical characteristics of metamorphic massif units outcropping in Goksun, Afsin and Ekinozu (Kahramanmaras) region(Maden Tetkik Ve Arama Genel Mudurlugu-Mta, 2020) Hozatlioglu, Deniz; Bozkaya, Omer; Yalcin, Huseyin; Yilmaz, HuseyinThis study aims to investigate and correlate the mineralogical-petrographic characteristics of Metamorphites in Goksun, Afsin and Ekinozu in the Southeast Anatolian Metamorphic Massifs. In this context, the optical microscopy and XRD investigations were performed on several samples. Goksun Metamorphites are constituted by phyllite, calcphyllite, marble and they contain mainly calcite, dolomite, quartz, feldspar, phyllosilicate. KI and b-cell dimension data reflect high anchizone-epizone and medium pressure conditions. Afsin Metamorphites are represented by phyllite, calcphyllite, calcschist, micaschist, amphiboleschist, marble. Phyllosilicates have consisted of illite/mica, IIb chlorite, mixed-layers, smectite. KI and b-cell dimension data correspond to the subgreenschist-greenschist facies conditions. Ekinozu Metamorphites are made of chloriteschist, amphiboleschist, micaschist, micagneiss in lower parts, while calcitic and/or dolomitic marbles are present in the upper parts. Mica is dioctahedral and trioctahedral, whereas chlorite tends to be trioctahedral. Based on mineral associations, Ekinozu Metamorphites belong to amphibolite facies in the lower parts, but the greenschist facies conditions at the upper parts. The coarse-grained biotite, muscovite and chlorite are accompanied by mixed-layers. According to mineral composition and degrees of metamorphism, Goksun and Afsin Metamorphites are similar to the Keban and Malatya Metamorphites; however, Ekinozu Metamorphites to Puturge Metamorphites. The data show that metamorphics in the western extension of the Southeast Anatolian Metamorphic Massifs have different origin and/or lithologies according to the regions, increasing temperature-pressure conditions from Goksun to Ekinozu and have groups of rock with different geological evolutions.Öğe Origin and evolution of the Southeast Anatolian Metamorphic Complex (Turkey)(SLOVAK ACAD SCIENCES GEOLOGICAL INST, 2007) Bozkaya, Omer; Yalcin, Huseyin; Basibuyuk, Zeynel; Ozfirat, Olcay; Yilmaz, HuseyinThe Southeast Anatolian Metamorphic Complex comprises three structural units, the Keban, Malatya and Puturge-Bitlis Metamorphics. Of these, the Keban Metamorphics (Carboniferous-Triassic) mainly comprise metamorphosed limestones/marbles and phyllites, consisting mainly of calcite, dolomite, quartz, albite, phyllosilicates (kaolinite, 2M(1), white K-mica, IM biotite, IIb chlorite, C-S, C-V and I-S) and scarce tremolite/actinolite and biotite, which were metamorphosed under sub-greenschist- to greenschist-facies conditions. The Malatya Metamorphics (Carboniferous-Triassic) comprise mainly metacarbonate rocks and metapelites - made up of calcite, quartz, albite, phyllosilicates (anchizonal-epizonal 2M, white K-mica and paragonite, IIb chlorite, dickite, C-V, C-S, I-S), chloritoid and goethite - that underwent a sub-greenschist-facies metamorphic event. The Puturge Metamorphics (Precambrian-Permian) comprise metamorphic lithologies of pie-Devonian high-grade (augen gneiss, amphibolite, mica schist/gneiss, granitic gneiss) and post-Carboniferous low-grade rocks (calc-schist/ marble and schist). The high-grade parts of this metamorphic unit display a Barrovian-type prograde metamorphism at amphibolite facies. Retrograde mineral occurrences, such as chlorite, C-V and C-S from garnet and biotile, reflect post-metamorphic-peak cooling assemblages. Low-grade parts of this unit are made up of calcite, dolomite, albite, phyllosilicates (IIb chlorite, 2M, muscovite and IM biotite, C-S), reflecting greenschist-facies metamorphic conditions. Lithological and mineralogical characteristics of the Southeast Anatolian Metamorphic Complex imply the following: the Xeban Metamorphics are similar to the Eastern Taurus Autochthon (Geyikdagi Unit) and apparently originated from that unit. In spite of their similar age ranges, the Malatya Metamorphics are quite different from the Keban Metamorphics and were probably derived from northern allochthonous Tauride units (e.g. Aladag Unit). The Puturge Metamorphics originated from a southern source (i.e. the Arabian Platform), and horizons of similar age differ from those of the Keban and Malatya Metamorphics.Öğe P-T-X constraints on the Koru epithermal base-metal (± Au) deposit, Biga Peninsula, NW Turkey(Elsevier, 2020) Bozkaya, Gulcan; Bozkaya, Omer; Banks, David A.; Gokce, AhmetThe Koru deposit is a typical intermediate sulfidation base-metal (+/- Au) example of volcanic-volcaniclastic hosted mineralization in the Biga Peninsula and northwestern Turkey. Ore deposition was associated with the collisional and post-collisional tectonics related to the closure of the Tethys Ocean. Galena, baryte and quartz are main minerals, accompanied by minor amounts of sphalerite, pyrite, chalcopyrite, covellite and marcasite. The homogenization temperature of fluid inclusions indicates two distinct fluid pulses, one at a temperature commensurate with epithermal mineralization and boiling/near boiling conditions at c. 350 degrees C, with the second approximately 150-200 degrees C lower. Salinity in both instances was from 11.0 to 0.2 wt% NaCl. The dD and d18O values of water in equilibrium with early quartz and fluid inclusions plot close to the magmatic water box indicating the source of the high temperature fluid was magmatic. delta D and delta O-18 values from early and late baryte trend towards the meteoric water line (MWL), but this is not due to mixing with meteoric water, rather equilibration with alteration assemblages at decreasing temperature. LA-ICP-MS analyses of fluid inclusions reveal high Cu-Zn-Pb concentrations in the fluids, despite their low salinity, transported as chloride complexes. The range of temperatures within the early quartz and sphalerite mineralization can be explained by pressure variations during vein and fracture opening.
