13 research outputs found
Geology, Alteration and Geochemical Characteristics of Inlice (Konya-Turkey) High Sulphidation Epithermal Gold Deposit
Inlice high sulphidation epithermal gold deposit is located in the Erenlerdag-Alacadag Volcanic Complex (EAVC), approximately 40 km southwest of Konya city centre. The volcanic and volcano-sedimentary rocks seen in the study area are andesite, block and ash flow, basaltic andesite lava flow and andesite lava flow, from oldest to youngest. The youngest units unconformably covering the volcanic and volcano-sedimentary rocks are talus and alluvium. Four different alteration zones in the andesites moving from the centre of the alteration toward fresh rock are i) silicified zones (consisting of vuggy-sugary and chalcedonic/opaline quartz veins), ii) advanced argillic alteration, iii) intermediate argillic and iv) propylitic alteration. In addition, a potassic alteration zone consisting of magnetite, quartz, biotite and anhydrite was identified in the deep part of the Merkez Zone. The mineralisation is commonly represented by pyrite, and to a lesser extent enargite, chalcopyrite, covellite, chalcocite, sphalerite and marcasite. Petrographically, the fine-grained gold grains (between 2-6 mu m) are only observed in areas where sulphide minerals are oxidised.
The degree of geochemical variation in the alteration zones decreases from silicified zones to propylitic alteration, and this variation is largely consistent with the mineralogies observed in these zones. Moreover, enrichment in As, Sb, Bi, Ag and Au, and depletion in Zn and Ni are especially notable from fresh/least altered andesites towards advanced argillic alteration and silicified zones. In addition, studies showed that the high Pb value in chalcedonic/opaline textured quartz veins and low Rb/Sr value in advanced argillic alteration and silicified zones can be used as a geochemical guide, at least for the Inlice region.İnlice yüksek sülfidasyon epitermal altın yatağı, Erenlerdağ-Alacadağ Volkanik Kompleksi (EAVK) içerisinde
ve Konya ilinin yaklaşık 40 km güneybatısında yer almaktadır. Çalışma alanında stratigrafik konumlarına göre alttan
üste doğru andezit, blok ve kül akıntısı, bazaltik andezit lav akıntısı ve andezit lav akıntısı olmak üzere dört birime
ayrılan volkanik ve volkano-sedimanter kayaçlar, yamaç molozu ve alüvyonlar tarafından uyumsuz olarak örtülürler.
Andezitler içerisinde gözlenen alterasyonların merkezinden dışa doğru sırasıyla kovuklu-şeker ve kalsedonik/
opalin dokulu kuvars damarlarından oluşan silisleşmeler, ileri arjilik, ortaç arjilik ve piropilitik alterasyon zonları
tanımlanmıştır. Bu alterasyon topluluklarına ek olarak sadece Merkez Zonun derin kesimlerinde gözlenen manyetit,
kuvars, biyotit ve anhidrit içerikli potasik bir alterasyon zonu da tanımlanmıştır. Cevherleşmeler, yaygın olarak
pirit daha az oranda enarjit, kalkopirit, kalkosin, kovellin, sfalerit ve markazit gibi sülfid mineralleri ile temsil
edilmektedir. Petrografik olarak altın taneleri özellikle sülfid minerallerinin oksidasyona maruz kaldığı kesimlerde
saçınımlı olarak 2 ile 6 µm arası boyutlarda gözlenmektedir.
Alterasyon zonlarındaki jeokimyasal değişimin derecesi silisleşmelerden piropilitik alterasyona doğru
azalmakta olup, bu değişim, alterasyon zonlarında gözlenen mineralojik değişimle uyumludur. Bununla birlikte
taze andezitlerden ileri arjilik alterasyon ve silisleşmelere doğru özellikle As, Sb, Bi, Ag ve Au gibi elementler
zenginleşme gösterirken, Zn ve Ni’deki fakirleşmeler belirginleşmektedir. Ayrıca yapılan çalışmalar kalsedonik/
opalin dokulu kuvars damarlarındaki Pb ile ileri arjilik alterasyon ve silisleşmelerdeki düşük Rb/Sr değerlerinin en
azından İnlice bölgesi için jeokimyasal bir kılavuz olarak kullanılabileceğini göstermektedir
Mineralogical and geochemical comparison of skarns in the Akdağmadeni, Akçakışla and Keskin districts, central Anatolia, Turkey
Ph.D. - Doctoral Progra
Küre maden sahası yataklarında pirit deformasyon dokuları (Kastamonu-Türkiye)
The Küre volcanogenic massive sulfide deposits lie within the Kastamonu province in the western part of the Pontide tectonic belt of Turkey, and are hosted by ophiolite-related pre-Liassic basaltic sequences, Mineralogical studies of the pyritic massive sulfide deposits of the Küre mining district have shown that the sulfide assemblages, particularly pyrite, have undergone a history of deformation and metamorphism. The Küre volcanogenic massive sulfide deposits show a range of macroscopic and microscopic textures, which are also observed in metamorphosed VMS deposits elsewhere. These textures are cataclastic, annealing and fracture-filling textures which developed in two successive stages: cataclastic texture predominated during main deformational stages, whereas annealing and fracture filling textures predominate during late-deformational stages. Cataclastic texture predominantes in polycrystalline and coarser-grained pyrite. Little or no cataclastic texture is observed in single, fine-grained pyrite crystals. Annealing is characterized by recrystallization of pyrite, while fracture filling is characterized by replacement and infilling of cataclastic fractures in pyrite grains by chalcopyrite. Cataclastic deformation texture is likely to have formed at about 400°C to 500°C and at 1 kb to 3 kb pressures, typical of low-grade and/or greenschist-facies metamorphic conditions. Whereas annealing textures dominate at temperatures over 500°C-550°C and at 0.69 kb to 1.7 kb pressures, typical of upper greenschist-/amphibolite-facies metamorphism. Fracture-filling textures, however, should have formed at less than 600°C and less than 500 bars. These temperatures indicate the maximum temperatures that could be reached in such deformation processes. The actual temperatures should be less than these values. The coexistence of at least two or all of the textures in at least one sample from the Küre massive sulfide deposits may indicate that the ore bodies were subjected to a progressive deformation/metamorphic event, ranging from greenschist-to upper greenschist- or even to amphibolite-facies conditions. The imbricate thrust fault and plunging anticlinal/synclinal structures between the Akgöl Formation and the Küre Ophiolite, which postdate the formation of the massive sulfide deposits, may have been the driving mechanism for the development of deformational- and late-deformational textures in the district. Also, it is proposed that many of the copper-bearing minerals may have been remobilized from their original settings to nearby fractures during late deformational stages, this is a possible explanation of why the massive ore tends to be confined to fault planes rather than within altered basalt sequences
Madsan antimuan yatağında (Niğde, Türkiye) stibnitlerin ve piritlerin deformasyonu: Yerel deformasyonda basınç-sıcaklık koşulları göstergeleri
Mermerler ve gnayslar içerisindeki epitermal damarlardan oluşan Madsan antimuan yatağı Niğde ilinin (orta-güney Türkiye) güneydoğusunda yer alır. Damarlar ana bileşenler olarak kuvars, kalsit, stibnit ve pirit içeren basit bir mineralojiye sahiptir; zinober iz miktarlarda bulunur. Özellikle stibnit ve piritte gelişen bir dizi dokunun işaret ettiği ilerleyen bir deformasyon yatağı etkilemiştir. Ana dokular basınç lamelleri ve kaynaklanma olup, eğilme, basınç lamellerinin ötelenmesi ve çatlak dolguları ikinci derecede önemli dokulardır. Bu dokular birbirini izleyen üç deformasyon evresinde gelişmişlerdir. Basınç lamelleri bölgedeki deformasyonun ilk evresini temsil ederler; ikinci deformasyon evresinin temsilcileri eğilmiş basınç lamelleri ve kaynaklanma dokularıdır; üçüncü deformasyon evresi basınç lamellerinin kesilmesi ve ötelenmesi ile belirginleşir. Deformasyonlar olasılıkla 180 °Cye kadar ulaşan sıcaklıklarda ve 0.2 MPa dolayında basınç altında gelişmiştir. Jeolojik veriler, Niğde Masifinin güneye doğru Ulukışla Havzasına bindirmesi ile deformasyonun birinci evresinin açıklanmasını desteklemektedir. Deformasyonun ikinci evresinin nedeni ilk deformasyonun bitiminden sonra stibnitlerdeki iç sıkışma kuvvetlerinin artmasıdır. Deformasyonun üçüncü evresi, yatağa yakın genç normal faylanmaların sonucudur.The Madsan antimony deposit at the southeastern part of the Niğde province (south-central Turkey) includes a series of epithermal veins hosted by marbles and gneisses. The veins have a simple mineralogy of quartz, calcite, stibnite and pyrite as major constituents, and cinnabar occurs in trace amounts. The deposit experienced a progressive deformation evidenced by a set of textures developed especially in stibnite and pyrite. These are pressure lamellae and annealing as the main textures, and curvature, off-set of pressure lamellae and fracture filling as the textures of minor importance. These were developed in three successive deformation phases. Pressure lamellae represent the first stage of deformation in the region, while the second stage of deformation is represented by curved pressure lamellae and annealing texture, and the third stage of deformation is characterised by truncation and offset of pressure lamellae. The deformations probably occurred at temperatures reaching 180°C and at pressures about 0.2 MPa. Geological evidence supports that the first phase of deformation is explained by the southward thrusting of the Niğde Massif over the Ulukışla Basin. The second phase of deformation is due to an increase in internal compression within the stibnites after the first deformation ended. The third phase of deformation is the direct result of younger normal faulting close to the deposit
An approach to geochemical characterization of productive versus barren granitoids in terms of iron in Central Turkey
The granitoids associated with, and without skarn type mineralizations in central Anatolia are termed as productive and barren granitoids, respectively. The study of the relationships between plutonic rocks in the Central Anatolian Crystalline Complex in central Turkey suggests a direct genetic connection between the composition of plutons, and their associated ore deposits. In order to discriminate between productive and barren granitoids, two Fe-skarn granitoids (Celebi and Karamadazi), and a series of barren plutons within central Anatolia were examined. The Karamadazi and Celebi granitoids are geochemically different from other barren plutons in Central Anatolia. The parameters governing the productivity of these granitoids were determined by principal component analysis (factor analysis) method. Based on this method, the factors controlling the geochemical characteristics of the Celebi granitoids are (Al2O3 + MgO + Fe2O3 + P2O5 + TiO2 + CaO)/(SiO2), (K2O + Rb)/(Na2O) and Rb/Sr ratios, and for the Karamadazi granitoid the Fe2O3 + MnO + MgO + P2O5 + Y)/(SiO2 + Rb) (FMMY/S) and (Na2O)/(K2O) ratios. These two granitoids are clearly distinguished from the barren Central Anatolian Granitoids (CAG) on Harker diagrams based on these controlling factors (parameters). Barren CAG plutons are different from the productive Celebi granitoids in their higher silica content and generally higher total alkali values. This study suggests that iron-producing granitoids are less differentiated and receive little contribution from continental crust compared to the barren granitoids. Higher apatite and zircon abundance in the Celebi granitoids suggest that the Celebi granitoids have more I-type characteristics compared to barren plutons of CAG. The Karamad granitoid is the most striking example for the granitoids in CAG, having a higher contribution from the continental crust as evidenced by higher Rb, Ba, Th, the highest mean Sc, V, and mean Zr, Y, Ni contents. Based on the factor analysis, it is proposed that the Karamadazi granitoid displays geochemical characteristics similar to the Terlemez and Agacoren granitoids of CAG. The factor analyses indicated that the first two factors are about the same for both the Fe-producing Celebi and Karamadazi granitoids. Therefore, this similarity has let to a conclusion that the productivity or non-productivity of the granitoids in Central Anatolia can be tested by examining and comparing the distribution of granitoids in diagrams designed according to the factors defined in this study. © 2004 Elsevier Ltd. All rights reserved.National Council for Scientific ResearchThe authors thank to Scientific and Technical Research Council of Turkey that funded this study (TUBITAK, project no: YDABCAG 198Y098). Prof. Dr N. Karahanoglu and an anonymous referee resulted in improvements to this manuscript
Hydrothermal Iron Oxide Cu Au Related Deposits A Global PerspectiveVolume 4 Advances in the Understanding of IOCG Deposits
Geology and the alteration features of the Çataltepe (Lapseki- Çanakkale) Pb-Zn±Cu±Ag deposit
Demirela, Gökhan (Aksaray, Yazar)Biga Yarımadası’nın KB ucunda ve Çanakkale ili Lapseki ilçesi doğusunda yer alan Çataltepe Pb-Zn±Cu±Ag yatağı, Kretase yaşlı Çamlıca metamorfitlerinin mermerleri içinde ve onların diğer kayaçlarla olan dokanakları boyunca genellikle litolojik kontrollü olarak gelişmiş bir cevherleşmedir. Şu an aktif olarak üretim yapılan işletme alanında cevherleşmelerin genel doğrultu/eğimi mermer ve diğer metamorfitlerin genel doğrultu/eğimine uyumlu olup yaklaşık K40oB/40oKD’dur. Mikroskobik çalışmalar prograd evreye özgün granat ve piroksen minerallerinin varlığını ve bu minerallerin retrograd evrede karbonatlaşıp epidotlaştığını göstermektedir. Cevher mineralleri olarak kahverengi sfalerit, bal renkli sfalerit, galenit, kalkopirit, pirit, pirotin, valeriit, manyetit, hematit, markazit, arsenopirit ve limonit mineralleri izlenmektedir. Retrograd evre sırasında gelişen cevherleşmeler dokusal olarak masif dokulu cevherleşmeler ve saçınımlı dokulu cevherleşmeler olmak üzere iki gruba ayrılmakta ve masif dokulu cevherleşmeler saçınımlı dokulu cevherleşmeler tarafından kesilmektedir. Bu cevher minerallerine karbonat, klorit ve kuvars mineralleri eşlik etmektedir. Geç evre alterasyonlar başlıca manganoksit-hidroksit, limonit, karbonat ve kalsit mineralleri ile temsil edilmekte olup prograd ve retrograd evre alterasyonlarını maskelemektedir. Çalışmalar sırasında elde edilen veriler, Çataltepe Pb-Zn±Cu±Ag yatağının mermer-metakumtaşı/kuvarsit dokanakları boyunca ve esas olarak mermerler içinde bir magmatik etki ile evrimleşen cevherli çözeltilerden itibaren oluştuğuna işaret etmektedir. Ayrıca veriler, sıcaklık bakımından mezo-epitermal koşullarda oluşan distal Pb-Zn skarn yataklarına göre biraz daha sığ kesimlerde ortaya çıkmış epijenetik bir yatağı önermektedir.The Çataltepe Pb-Zn±Cu±Ag deposit, to the east of Lapseki (Çanakkale), in the northwestern part of Biga Peninsula, is hosted by marbles, and at the contact between marbles and other rocks of the Çamlıca metamorphics (Cretaceous). In the area, still under operation, the strike and dip of the mineralization are N40W/40o NE which is nearly parallel to schistosity of marbles and other metamorphic rocks. The microscopic investigations indicate that garnet and pyroxene minerals have been formed during prograde stages which were carbonatized and epidotized during the retrograde stage. The ore minerals are brown and honeyblende sphalerite, galena, chalcopyrite, pyrite, pyrrhotite, valleriite, magnetite, hematite, marcasite, arsenopyrite and limonite. The textural characteristics are suggestive of two subsequent mineralization at the retrograde; massive and disseminated ore, and the former is always cut by the latter. The ore mineral assemblage is accompanied by carbonate, chlorite and quartz. The late-stage alterations which are represented by manganese oxide-hydroxide, limonite, calcite and quartz, mask the prograde and retrograde stage alterations. Our data indicate that the Çataltepe Pb-Zn±Cu±Ag deposit was formed by ore-bearing solutions circulating particularly within marbles and along the marble-metasandstone/quartzite contacts. The data also favors an epigenetic origin for formation of the deposit under meso-epithermal conditions in areas relatively shallower than distal Pb-Zn skarn deposit
Geology and stratigraphy of Hod (Artvi̇n) Region, Eastern Pontides, NE Turkey
This study reports a revised geological map and a stratigraphic section of the Hod region. It represents a synthesis of new data and earlier work. New results gathered from field geological mapping and petrographic investigation have clarified the lithological boundaries, textural characteristics, the stratigraphical relationships between various rock formations and spatial distribution and behavior of structural elements. Hod region, located in the eastern part of the eastern Pontides (Artvin district), comprises Jurassic to Cretaceous volcanic and sedimentary sequences with a roughly north-north-east trending, steeply east dipping stratigraphy. These lithological units are Liassic Berta Formation, Dogger Kırgülü Formation and Hızarlıdere Formation, Malm-Lower Cretaceous Öğdem Formation and İnanlı Member, Lower Cretaceous Aşağımaden Formation, Turonian Çatak Formation, Santonian Kızılkaya Formation and Santonian-Campanian Evliyatepe Formation. Among these formations, intermediate to felsic volcanic and volcanosedimentary rocks of Kızılkaya Formation are significant as they host several volcanogenic massive sulfide (VMS) and epithermal deposits throughout eastern Pontides. Hod Maden Au-Cu deposit which represents one of the highest-grade gold and copper discoveries made globally in recent years is also located in Hod region. Therefore, the revised geological map and stratigraphy presented here are important contributions to the regional geology and essential tools for exploration geologists working in the region.</p
Factor analysis method in geochemical characterization study: Çelebi granitoide and Karamadazı granite
Ana bileşen analiz yöntemlerinden "faktör analizi yöntemi" bu çalışmada Karamadazı ve Çelebi granitoyidlerinden elde edilen jeokimyasal analiz sonuçlarının değerlendirilmesinde kullanılmıştır. Buna göre, Karamadazı Graniti'nin jeokimyasal davranışını kontrol eden faktörler ve olarak, Çelebi Granitoyidi'nin jeokimyasal davranışını kontrol eden faktörler ise ve olarak bulunmuştur. Bu faktörlerin esas alındığı Harker tipi diyagramlarda iki bölgedeki granitoyidlerin de bu çalışmada kısır olarak adlandırılan granitoiydlerden belirgin şekilde ayrıldığı gözlenmiştir. Yozgat batoliti, Terlemez kuvarsmonzoniti, Kerkenez graniti, Ekecikdağ kuvarsmonzoniti ve Ağaçören intrüzif takımı gibi Orta Anadolu Granitoyidleri Çelebi Granitoyidi'ne göre daha yüksek silika değerleriyle ve kısmen yüksek toplam alkali değerleriyle farklılaşmaktadır. Bu granitoiydlerin magmatik farklılaşma gösterdikleri ve üretken plütonlann kısır olanlara göre daha az farklılaşmaya uğradıkları öne sürülmektedir. Çelebi Granitoyidinin apatit ve zirkon açısından kısır granitoyidlere göre daha zengin bileşimde olması Çelebi Granitoyidi'nin kısır granitoyidlere göre daha fazla I-tipi karakterinde olduğunu göstermektedir. Karamadazı Graniti, Yozgat batoliti, Terlemez kuvarsmonzoniti, Ekecikdağ kuvarsmonzoniti ve Ağaçören intrüzif takımı gibi Orta Anadolu Granitoyidleri arasında en düşük ortalama Rb, Ba veTh değerleri ve en yüksek ortalama Sc ve V, ve ortalama Zr, Y ve Ni değerleriyle diğerlerine kıyasla kıtasal kabuktan en az malzeme almış granitoyidler olarak göze çarpar. Faktör analizlerinden elde edilen faktörlere göre, Karamadazı Graniti'nin Terlemez ve Ağaçören granitoyidleriyle benzer özellikler sunduğu, ve diğerlerinden belirgin bir şekilde ayrıldığı gözlenmektedir.The principal component analysis, one of the methods in factor analyses was used to evaluate the geochemical composition of Karamadazi and Çelebi granitoids. Based on this method, the factors controlling the geochemical characteristics of the Karamadazi Granite are and ratios, and for the Çelebi Granitoids the and ratios. These two granitoids are clearly distinguished from the sterile/non-productive Central Anatolian Granitoids (CAG) on Harker diagrams based on these controlling factors, (parameters). CAG plutons such as Yozgat batholith, Terlemez quartzmonzonite, Kerkenez granite, Ekecikdağ quartzmonzonite ve Ağaçören intrusive suite are different from the productive Çelebi Granitoids in their higher silica content and generally higher total alkali values. This study suggests that fertile (iron producing) plutons are less differentiated and have very little contribution from continental crust compared to the sterile (non-productive) plutons. Higher apatite and zircon abundances in the Çelebi Granitoid suggest that the Çelebi Granitoid have more l-type characteristics compared to non-productive plutons of CAG. The Karamadazi Granite is the most striking example for the granitoids in CAG plutons above having the least contribution from the continental crust, evidenced by the lowest mean Rb, Ba, Th, the highest mean Sc, V, and mean Zr, Y, Ni contents. Based on the factor analysis, it is proposed that, the Karamadazi Granite display geochemical characteristics similar to the Terlemez and Ağaçören granitoids of CAG
Tectonic setting and petrogenesis of the Çelebi granitoid, (Kırıkkale-Turkey) and comparison with world skarn granitoids
Many studies have shown systematic correlations between the composition of plutons worldwide and the metal content of associated skarns. This is the first report of similar correlations between the composition of Çelebi granitoid and skarns of the Çelebi district in Central Anatolia, Turkey. The Çelebi district is well known for its polymetallic Fe-W and Cu vein ores. These are hosted by calcic skarn zones. Both exoskarns (pyroxene-garnet) and endoskarns (epidote-pyroxene) occur in the district formed mainly along the granitoid contacts and along the fractures within the marble. Based on mineralogy, petrology and geochemistry, two different igneous rocks were recognized in the Çelebi granitoid, referred to as leucocratic (felsic) and mesocratic (intermediate) Çelebi granitoid. The leucocratic Çelebi occurs as dominant rock type, and is classified as granite. The mesocratic Çelebi is not widespread and is classified as adamellite, tonalite, quartz monzonite and quartz monzodiorite. The mesocratic Çelebi has I-type characteristics, and have subalkaline, calc-alkaline and metaluminous characteristics like most worldwide skarn granitoids. A post-collisional tectonic setting is proposed on the basis of field evidence, the relative timing of intrusions with respect to metamorphic and obducted ophiolitic rocks and trace element geochemistry. The high abundance of La and Ce and the enrichment of V in mafic components suggest that Çelebi granitoids are formed by partial melting of mantle rocks, but have been contaminated by interaction with continental crust involving possible magma mixing processes (i.e. mixing of coexisting felsic and mafic magmas). In the district, the mesocratic type and mafic microgranular enclaves (MME) mainly within leucocratic type represent a mafic underplating magma that was mixed with and/or injected into felsic magma of the leucocratic type. The present study shows that Fe mineralization is associated with mesocratic Çelebi type, whereas W mineralization is associated with leucocratic type. Mesocratic Çelebi granitoid is significantly different from the worldwide average of plutons associated with Fe skarns. In particular, MgO vs. SiO2, FeOt+CaO+Na2O/K2O vs. SiO2, Fe2O3/Fe2O3+FeO vs. SiO2 and V vs. Ni vary from typical values (are lower than values typical for plutons associated with Fe skarns) for plutons associated with Fe skarns. Instead, it resembles the geochemical characteristics of plutons associated with worldwide Cu and possibly Au skarns. This suggests new exploration possibilities for copper and gold in the Çelebi district.The authors wish to thank two anonymous reviewers who have contributed much and improved the content and clarity of the paper. Funding by Scientific and Technical Research Council of Turkey (TÜBİTAK, grant code YDABÇAG-198Y098) is gratefully acknowledged