Bulletin of the Mineral Research and Exploration (BMRE)
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ORIGINAL FINDINGS ON THE ORE-BEARING FACIES OF VOLCANOGENIC MASSIVE SULPHIDE DEPOSITS IN THE EASTERN BLACK SEA REGION (NE TURKEY)
No full textIn the massive sulphide deposits of the eastern Black Sea region, there are ore facies and ore-bearing sedimentary facies. The former are subdivided into hydrothermal-metasomatic, seafloor hydrothermal, and biological facies. Hydrothermal-metasomatic facies refer to sub-seafloor processes and include network-disseminated, massive vein, and massive lens facies. The precipitation of sulphide minerals within pre-existing volcano-sedimentary rocks occurs largely beneath the seafloor, and these ores form an important component of some deposits. The term seafloor hydrothermal facies refers to sulphide accumulation on the seafloor and is characterised by hydrothermal chimneys and clastic sulphide ores. Clastic sulphide ores can be subdivided into proximal and distal facies. Ore-bearing sedimentary facies are characterised by relatively thin ferruginous chert (exhalite?) beds that occur along the uppermost part of the ore horizon. The biological facies is represented by fossil vent fauna, which are diagnostic for seafloor sulphide formation.
The VMS ores of the eastern Black Sea region have well-preserved facies characteristics, especially in terms of texture and components. Some massive sulphide deposits accumulated via molasse/mass flow on the seafloor, whereas others formed via sub-seafloor replacement processes. Clastic sulphide textures and some sedimentary structures indicate that these deposits formed in a highly active setting. Clastic sulphide textures, sulphide chimney fragments, ferruginous cherts and fossil vent fauna (tube worms) recognised in the Pontide deposits are diagnostic and support the seafloor origin of VMS deposits
PETROGENETIC CHARACTERISTICS OF OYACA – KEDİKAYASI – BOYALIK ADAKITES IN SW ANKARA (CENTRAL ANATOLIA, TURKEY): EVIDENCE FOR SLAB MELT METASOMATISM
No full textThe Early Miocene Oyaca, Kedikayası and Boyalık dacites, situated approximately 50-60 km southwest of Ankara have affinities similar to adakitic rocks. They have porphyritic texture with a variable amount of plagioclase feldspar, hornblende and lesser biotite phenocrysts and a groundmass of plagioclase and quartz microcrysts. They have high Sr/Y (55-79 ppm) and (La/Yb)n (21-32 ppm) ratios, and low Y (10-19 ppm) and heavy rare earth element contents. According to their SiO2 (62.3-69.70 % wt.) and MgO (0.62-2.23 % wt) contents, they are referred to as high silica adakites, indicating the effects of slab-derived melts in their genesis. The adakites in the study area are enriched in Large Ion Lithophile Elements (LILE) (e.g., Ba: 800-1395 ppm, Sr≥720 ppm) relative to High Field Strength Elements (HFSE) (e.g. Nb: 20-10 ppm, Ta: 0.8-1.2 ppm). Low Rb/Sr and high Ba/Sr ratios in these adakites indicate that they are resulted from an amphibole bearing mantle source, as amphiboles have low Rb concentrations. Thus, partial melting of an amphibole bearing mantle source would be responsible for low Rb concentrations). For that reason, nonmodal partial melting calculations from a 13 % amphibole bearing garnet peridotite were carried out in order to determine the source features of adakites. The variations between La/Yb vs La and (Tb/Yb)n vs (La/Yb)n in partial melting studies demonstrate that the adakites in the study area were most probably derived from an amphibole bearing garnet peridotite mantle source via 5-10 % degrees of partial melting
THE SEGMENT STRUCTURE OF SOUTHERN BRANCH OF THE NORTH ANATOLIAN FAULT AND PALEOSEISMOLOGICAL BEHAVIOUR OF THE GEMLİK FAULT, NW ANATOLIA
No full textThe North Anatolian Fault (NAF), which is an intra-continental transform fault, is divided into two branches as Northern and Southern branches in Marmara Region. The southern branch which separates from each other by rightward stepovers between Bandırma and Dokurcun valley is formed by three main fault segments as Geyve, İznik and Gemlik from East to West. The length of fault segments ranges between 40 and 57 km and GPS data in Southern branch propose a 5 mm/year slip rate. Two surface faulting events were observed during paleoseismological excavations which had been carried out on 40 km long Gemlik segment and these can be correlated with earthquakes that occurred in 1857 and 1419. The recurrence interval between the last two earthquakes in Gemlik Fault is 438 years. Findings indicate that Gemlik fault was also included into surface faulting of the earthquake in 1419 which its presence is known in İznik fault. At least 95 km long multi-segment surface faulting developed in this earthquake. Based on 5 mm/years slip rate, the cumulative offset amount slip rate of NAF was approximately estimated as 3 meters in 595 years in region between İznik Lake and Dokurcun Valley. Accordingly; it can be stated that the southern branch of the North Anatolian Fault has a potential to trigger a large earthquake as well as the Northern branch
HYDROGEOCHEMICAL AND ISOTOPIC INVESTIGATION OF NASRETTIN HOCA SPRINGS, ESKİŞEHİR, TURKEY
No full textNEW APPROACHES ON THE INVESTIGATION OF COVERED GEOTHERMAL FIELDS: EXPLORATION OF KÜTAHYA – ŞAPHANE – KARACADERBENT BURIED GEOTHERMAL FIELDS AND THEIR DEVELOPMENTS
No full textThe basement in Şaphane region is constituted by Paleozoic gneiss, schist and marbles belonging to northern margin of the Menderes Massif. These basement rocks are overlain by Cretaceous aged Dağardı ophiolitic melange. All these rocks are discordantly covered by Neogene – Quaternary sedimentary and volcanic rocks deposited under lacustrine – continental environments. The main purpose of this study is to explore buried geothermal system on a covered area using geological, geophysical and geochemical methods and to develop this system by drilling investigations. Geological, geophysical, geochemical and drilling investigations, well development and test studies were applied in this research. This study is a typical example for geothermal researches carried out in covered areas. Thus, a new approach was aimed to be brought out in such investigations. Especially; the profiling was applied, and geological structures and geochemical data were used for the selection of profiles at geophysical investigations instead of gridding which had typically been used for many years. The geothermal system was handled in regional scale rather than local scale with this study. As a result of research assessments, a drill location was selected on a totally covered area where there was no surface data around Şaphane Karacaderbent. At drilling number KŞÜ-3, a reservoir temperature of 181,2ºC were reached at a depth of 2500 m. From the well which its development and test studies had been completed at 10 psi at wellhead pressure (WHP), vapor + water production was obtained at a temperature of 114ºC and a flow rate of 25 I/s in case of artesian. As for the production tests carried out by compressor at 22 PSİ well head pressure (WHP), vapor + water was obtained at a temperature of 112ºC and a flow rate of 35 l/s. The fluid obtained from the well is suitable for the production of electricity and for heating of houses and greenhouses due to the production values revealed at the end of temperature and tests. When turbine rejection heat is taken as 75ºC, the apparent potential of electrical energy in the well is 21,3 MWt and owns a potential to heat 1300 houses or an area of 85000 m2 for greenhouses
THE OSTRACOD FAUNA AND ENVIRONMENTAL CHARACTERISTICS OF THE VOLCANO SEDIMENTARY YOL ÜSTÜ FORMATION IN THE HINIS REGION, ERZURUM (EASTERN ANATOLIA), TURKEY
No full textThe volcanosedimentary Yolüstü formation which outcrops in the vicinity of Hınıs Town, the southeast of Erzurum City, consists of conglomerate, marl, agglomerate, claystone, tuffite, fragmented travertine limestone with fragments of sand – pebble - plant, lacustrine limestone and tuffaceous – clayey limestone. In this formation, carefully selected 3 measured stratigraphic sections were taken at levels in which the lithology of hard travertine limestones with plant fragments and soft tuffaceous – clayey limestone are present. Washed samples which had been taken from these sections were studied and assessed, and then ostracods reflecting freshwater and brackish water environments were detected. In the unit, 5 genera and 12 species of ostracod and their taxonomies, which are generally peculiar to Ponto – Caspian basin, were defined. Besides; few micro mollusks, and 2 genera and 1 species of gastropod and 1 species of pelecypod (non well preserved) were found from the recrystallized looking tuffaceous, clayey, consolidated, hard limestone levels. In sequence, genera and species types of osracod such as; Leptocythere (Amnicythere) cf. litiva Livental, Tyrrhenocythere bailovi (Suzin), Loxoconcha granulata Sars, L. cf. diligena Kulieva, L. agilis Ruggieri, Candona (Caspiocypris) araxica Freels, C. (Caspiocypris) erzurumensis Freels, C. (Caspiocypris) aff. alta (Zalanyi), C. (Typhlocypris) amblygonica Freels, C. (Candona) parallela pannonica Zalanyi, C. (Candona) burdurensis Freels, C. (Candona) candida (O.F.Müller), C. (Candona) sp. 1 Freels, gastropods like Valvata piscinalis (O.F.Müller), Viviparus sp. and genus and species types of pelecypod like Dreissena polymorpha (Palas) were defined. For the main fossil envrionmtents; Leptocythere and Tyrrhenocythere indicate the brackish water environment, Loxoconcha mesohaline, Candona (Caspiocypris), C. (Typhlocypris) oligohaline, Candona (Candona), Valvata, Viviparus and Dreissena indicate the freshwater environment
NEOGENE STRATIGRAPHY OF THE ESKİŞEHİR GRABEN AND THE INVESTIGATION OF COAL DEPOSITION BY SEISMIC REFLECTION METHOD
No full textA NEW AGE FINDING IN THE CENTRAL SAKARYA REGION (NW TURKEY)
No full textThe existence of a metamorphic basement cut by granitoids is known in the Central Sakarya region of northwest Turkey according to the previous studies. Over this metamorphic basement, there is a Liassic unit which contains ammonite, brachiopod and some benthic foraminifers and has a sequence starting with fluvial deposits at the base and grading into coastal, subtidal and shallow marine sediment character towards the top in the vicinity of Sarıcakaya district, Eskişehir City. At different levels of this unit which is called as the “Kapıkaya Formation”, the Campanian age fossils such as; Ceratolithoides aculeus (Stradner), Pervilithus varius Crux, Watznaueria barnesae (Black), Tortolithus sp., Biscutum sp. Quadrum sissinghii Perch-Nielsen, Watznaueria barnesea Black, Ellipsagelosphaera fosscincta were identified in this study. These fossil findings clearly reveal the presence of a Campanian aged unit in the region. This unit is composed of flyschoidal facies deposits and includes exotic limestone blocks of Liassic age and is overlain by Malm – Early Cretaceous limestones at the same time. The overlying of Malm – Early Cretaceous rocks to Campanian deposits is closely related to the tectonics that has been effective in the region during or post Campanian
SLOPE INSTABILITY IN OPEN PITS AND AN EXAMPLE OF A RETROSPECTIVE ANALYSIS: AFŞİN-ELBİSTAN-KIŞLAKÖY OPEN PIT COAL DEPOSIT
No full textThe subject of this study is to study the instabilities that have developed in the permanent east and west slopes of the Kışlaköy open pit of the Elektrik Üretim A.Ş. Afşin-Elbistan Linyitleri İşletmesi and to work out the sliding mechanism causing it. In the Kışlaköy open pit to establish if mass movement is continuing and if so which direction it would move, amount of mass to be involved and the failing model. Six movement control observations stations were established along 3 lines in each of west and east slopes. No movement was observed in the west slopes. On the other hand up to 90 cm cumulative movement was observed at the at D24 and D18 observation station on the east slopes. Measurements taken showed that there were failings in the lignite horizon fitting to the ‘block sliding model’. During the field study circular sliding model type failings were observed in the basal units. In the open pit in general before and after the sliding, plans were prepared of the instabilities to enable geometries could be worked out. By using these plans cross sections were prepared to show the geometry of the instabilities before it actually took place and retrospective analyses of the failing model have been carried out. Correlations have been made of the results of the retrospective analyses and resistance parameters obtained from the laboratories. It was concluded that during the movement of the mass, shear strength of the sliding planes were then represented by the shear resistance parameters. During the study it was found out that the black coloured clay band with high plasticity within the lignite horizon is one of the most crucial factors controlling slope stabilities
ORGANIC GEOCHEMICAL AND PETROGRAPHIC PROPERTIES OF HAZRO DADAŞ (DİYARBAKIR) COALS
No full textThis study was carried out in Hazro-Dadaş (Diyarbakır) region which owns the only coal basin in the area. Chemical, petrographic analysis and organic geochemical evaluations of the Permian aged coals were taken into consideration. Coal quality investigation along with proximate (moisture, volatile matter, fixed carbon, ash) and elemental analyses (C, H, O, and S, N) were performed and revealed. The huminite reflectance of organically abundant matter and coal levels were found to be between 0.458 and 1.141 %. This parameter complies with fluorescence colors, calorific value (average original 3165 – 3432 Kcal/kg) and average Tmax (418 oC). Hasbro coals show low grade maturity and own sub-bituminous, bituminous coalification ranks. This is thought to be resulted from thin overburden and its possible low lithostatic pressure. Rock Eval analysis results show that Type II/III and III kerogen, with average Tmax value is 418 oC and corresponding to the immature and early-mature rank for hydrocarbon generation. The coals are characterized with their abundance of huminite maceral group and gelinite maceral, with small amount of liptinite and inertinite macerals. Mineral matters of the Hazro-Dadaş coals are clay, quartz and calcite minerals. Hazro-Dadaş coals are thought to have deposited in limnic environment swamps