Bulletin of the Mineral Research and Exploration (BMRE)
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THE IMPORTANCE OF BENTHIC FORAMINIFERAS IN DETECTING FEATURES OF ECOLOGICAL AND GEOLOGICAL STRUCTURES IN EDREMIT BAY AND ON COASTAL AREAS OF D‹K‹L‹ CHANNEL (NE AEGEAN SEA)
No full textBenthic foraminiferal assemblages from the Gulf of Edremit, Lesbos Island, Alibey and Maden islands and Dikili Bay have been investigated and various morphological abnormalities, as well as, colored tests and large sizes have been observed. Besides, abundance of alien species originating from tropical seas attracts attention. Interesting togethernesses were found between different genera and species. Significant differences were observed between the assemblages from the northwest and southeast coasts of the Gulf of Edremit. 57 genera and 97 species were identified in the samples from the northwest coast, where as only 32 genera and 48 species were found on the southeast coast. A diverse foraminifer assemblage were observed around the Ayval›k-Alibey and Maden islands, with large individual sizes, colored tests and morphological abnomalities. Abnormal togethernesses between different genera and species were also observed in this locality. Togethernesses between Peneroplis pertusus (Forskal)-Coscinaspira hemprichii Ehrenberg and Peneroplis planatus (Fichtel and Moll)- Coscinaspira hemprichii Ehrenberg are important findings in the benthic foraminiferal assemblages of Ayval›k Alibey and Maden islands. Orange and brown coloration observed on many Peneroplis pertusus (Forskal) and P. planatus (Fichtel and Moll) individuals is another important finding in this region. Besides, many individuals of Peneroplis pertusus (Forskal), P. planatus (Fichtel and Moll), Lobatula lobatula (Walker and Jacob), Cibicidella variabilis (d’Orbigny), Ammonia compacta Hofker, A. parkinsoniana (d’Orbigny), Challengerella bradyi Billman, Hottinger and Oesterle, Elphidium complanatum (d’Orbigny) and E. crispum (Linné) were found. The presence of Laevipeneroplis karreri (Wiesner), Peneroplis pertusus (Forskal) and P. planatus (Fichtel and Moll) and Sorites orbiculus Ehrenberg on the east coast of Lesbos Island indicates the presence of hotwater springs. An abnormally large Peneroplis planatus (Fichtel and Moll) individual were found. Besides, many Peneroplis pertusus (Forskal) and P. planatus (Fichtel and Moll) individuals with orange-yellow tests, like the ones in Ayval›k, were found, suggesting the presence of submarine springs with Fe content. An abnormal Peneroplis planatus (Fichtel and Moll) individual with three different apertures was found in Dikili samples. One of the apertures was typical of the species, whereas the other two have the aperture characteristics of Coscinospira hemprichii Ehrenberg. The aim of our study is to figure out the factors leading to abnormal test morphologies. It is suggested that the benthic foraminiferal assemblages found in the study area are affected by the physical environmental conditions such as, temperature and salinity, as well as the chemical factors, such as radioactivity
THE ASSESSMENT OF GEOTHERMAL POTENTIAL OF TURKEY BY MEANS OF HEAT FLOW ESTIMATION
No full textIn this study, the heat flow distribution of Turkey was investigated in the interest of exploring new geothermal fields in addition to known ones. For this purposes, the geothermal gradient was estimated from the Curie point depth map obtained from airborne magnetic data by means of power spectrum method. By multiplying geothermal gradient with thermal conductivity values, the heat flow map of Turkey was obtained. The average value in the heat flow map of Turkey was determined as 74 mW/m2. It points out existence of resources of geothermal energy larger than the average of the world resources. in terms of geothermal potential, the most significant region of Turkey is the Aydin and its surrounding with a value exceeding 200 mW/m2. On the contrary, the value decreases below 30 mW/m2 in the region bordered by Aksaray, Niğde, Karaman and Konya. The necessity of conducting a detailed additional studies for East Black sea, East and Southeast Anatolia is also revealed
CRITISISM ON THE PAPER “ POSSİBLE İNCİSİON TİME OF THE LARGE VALLEYS İN SOUTHERN MARMARA REGİON, TURKEY (N. KAZANC›, Ö. EMRE, K. ERTURAÇ, S. A.G.LEROY, S. ÖNCEL, Ö. İLERİ, Ö.TOPRAK)” APPEARED İN BULLETİN OF THE MİNERAL RESEARCH AND EXPLORATİON 148, 1-17.
No full textSTABILITY STUDIES OF THE EASTERN SLOPES OF AFfi‹N-ELB‹STAN, KIfiLAKÖY OPEN-PIT LIGNITE MINE (KAHRAMANMARAfi, SE TURKEY), USING THE ‘FINITE ELEMENTS’ AND ‘LIMIT EQUILIBRIUM’ METHODS
No full textIn open pit mining from the safety point of view it is very important that physical and mechanical characteristics of the dug-out materials are carefully studied, and geological and geotechnical characteristics should also be considered in planning bench slopes of the dug-out materials. The purpose of this study is to work out the stable slope geometry of the eastern permanent slopes in the K›fllaköy open pit lignite mine of the Afflin-Elbistan Linyit ‹flletmesi. In the K›fllaköy open pit mine, 35 geotechnical drillings totalling 3393.20 m were made for the geotechnical studies and to work out slope sizing. A total of 250 vertical electrical drillings (DES) were also made to study tectonic features and lithological changes which do not have surface expressions. All these data have been used in this study. Design analyses showed that black coloured clay bands with high plasticity present in between lignite horizon is the most important unit controlling slope stability. Slope stability analyses have in general been conducted using the ‘finite elements’ and the ‘limit equilibrium’ method to suit block sliding model and to suit different groundwater conditions. In the analyses for the stresses affecting the slices; central part of the slice has been taken as a base and the ‘finite elements’ stability studies have been conducted then the findings have been compared. According to this it is understood that if stresses affecting the slices are conducted by the ‘finite elements’ method then calculated factor of safety on the bench base would be more from 1% to 7%, and in the slope angles it would be more from 1% to 23%
FACIES CHARACTERISTICS AND CONTROL MECHANISMS OF QUATERNARY DEPOSITS IN THE TUZ GÖLÜ BASIN
No full textAlthough there are several studies discussing the pre-Neogene development of the Lake Tuz basin, which is the largest terrestrial basin in Turkey, investigations delineating the characteristics of the Neogene and particularly Quaternary period of this basin are quite limited. Whereas studies regarding such periods of the basin are quite informative for both active tectonics and climate change issues that are of significant public concern. In this study, results of field observations on temporal and spatial characteristics of Quaternary deposits in the Lake Tuz Basin and processes controlling these features are presented. For this, as a result of sequence studies conducted in 17 different areas, Quaternary units were described and examined under 12 lithofacies and 5 facies associations. Facies properties imply that tectonism is spatially determinant factor whilst climate is the dominant controlling mechanism in the Quaternary evolution
NEOGENE STRATIGRAPHY OF THE NORTHERN PART OF KARABURUN PENINSULA
No full textThe terrigenous Neogene lithology in north of Karaburun peninsula is represented by Lower- Middle Miocene rock units which are cut and bounded by NW-SE trending synthetic faults. Dominant lacustrine sedimentation (Haseki and Hisarc›k formations) of Early-Middle Miocene period which was separated by upper and lower regional unconformities, and the Early Miocene mafic volcanism (Karaburun volcanites) were studied within the scope of Karaburun group. Haseki formation which reflects Early Miocene sedimentation begins with fills of alluvial fan of the Salman member and is basically formed by algal-biostromal Yeniliman limestone and lacustrine deposits of Aktepe member. With synsedimentary emplacement of the 1st phase Karaburun volcanites over Yeniliman limestone platform, the dominant sequence which is micritic limestone intercalating with diatomite of the Aktepe member was deposited in environmental conditions deepening towards shore-face. The effectiveness of NW trending boundary faults which gave rise to 2nd phase of the Karaburun volcanism, shaping the western edge of Foça depression towards the end of Early Miocene has not changed the dominant depositional environment, and lacustrine sedimentation has continued with Hisarc›k formation. Green and fine clastic shore-face sediments (Karaba¤lar› member) of the Hisarc›k formation which deposited the latest between Early Miocene-Middle Miocene overlie Aktepe sequence with submarine parallel unconformity. Karaburun volcanism which is represented by high potassium andesitic products with calc alkaline character (pyroclastics and olivine- phyric lavas) is synchronous with sedimentation of Haseki formation and has two phases. Pyroclastic rocks which are in facies of base-surge, air-fall and ash-fall in lesser amount were emplaced before lava eruptions. K/Ar aged, 1st phase products, which are 18.2±1.0 my according to K/Ar dating, are in the position of stratigraphical reference level which separates Yeniliman limestone from Aktepe member. Second phase products are emplaced in Aktepe sequence
PROTOLITH NATURE AND TECTONOMAGMATIC FEATURES OF AMPHIBOLITES FROM THE QUSHCHI AREA, WEST AZERBAIJAN, NW IRAN
No full textAmphibolites from the Qushchi area in west Azerbaijan province, NW Iran are metabasites containing hornblende, plagioclase, epidote, garnet, relict igneous clinopyroxene and titanite, apatite and opaque minerals as accessory phases. They are spatially associated with an ophiolitic mélange but their relationship is not clear. Based on whole rock geochemistry of the amphibolites, they are formed from sub-alkaline andesite-basalt with a tholeiitic affinity. TiO2 content of the analyzed amphibolite samples is mainly less than 1%, indicating an E-MORB original character for the magma. Major and trace element geochemistry of the studied rocks indicate a volcanic arc setting for the rocks. Chemistry of relict igneous clinopyroxene shows that they are diopside in composition with Mg# of 86.75-88.78 and indicating tholeiitic magma type derived from volcanic arc setting, which is in agreement with the results from the whole rock chemistry. Low Ti content of the clinopyroxene points to a depleted mantle source for the magma of the protoliths of Qushchi amphibolites. There is no isotopic age constrains on the studied amphibolites, therefore their relation to the ophiolitic mélange of the area is uncertain especially that the mélange is allochthonous. Three possibilities can be proposed for the formation of the studied amphibolites. If these rocks are Late Cretaceous- Paleocene in age, they might have been formed as parts of a volcanic arc in the Neotethyan oceanic crust. In this case, the ophiolitic complex and the volcanic arc rocks all are metamorphosed at amphibolite facies following the Neotethys ocean closure and the continental collision. Based on field relations and comparing the studied amphibolites with similar amphibolites from the adjacent Khoy area, alternatively the amphibolite formation can be consider to predate the formation of Neotethys-related ophiolite mélange. Since the serpentinite in the ophiolitic mélange is not metamorphosed, the second explanations can be valid for the formation of the amphibolites. The third possibility is that the protolith of the amphibolites was contemporaneous with ophiolite formation, but this protolith is metamorphosed within the accretionary prism but the obducted ophiolitic rocks (including serpentinite) not subjected to metamorphism
NEOGENE STRATIGRAPHY AND PALEOGEOGRAPHIC EVOLUTION OF THE KARABURUN AREA, İZMİR, WESTERN TURKEY
No full textThe western margin of the Foça Depression (FD) is located in the NE of the Karaburun Peninsula. Terrestrial Neogene sediments in the study area which partly representing the western margin of the FD and the mafic volcanics have NW-SE directions towards ‹zmir bay and are separated from the basement rocks by synthetic normal faults. During the Miocene deposition the basin’s boundaries became structurally narrower and two main sedimentary successions have been defined namely the Karaburun group and the Eflendere group which have been separated with angular unconformity in regional scale. The Karaburun group is represented with dominantly lacustrine deposition in Early-Middle Miocene period that includes Haseki and Hisarc›k formations and Karaburun volcanics. The Lower Miocene Haseki formation is represented by the Salman member developed in the alluvial fan environment and lacustrine deposits of algal-biostromal Yeniliman limestone and micritic limestone dominated Aktepe member. NW trending basin margin faults which formed a boundary between Karaburun high and the FD and caused the effective second stages of mafic volcanism did not interrupt the lacustrine deposition at the beggining of the Early Miocene. But it caused relative deepening of the basin, changed depositional conditions and lacustrine sedimentation continued with the Hisarc›k formation. The activity shaping the FD from the western part and partly coinciding with the Early Miocene basin margin faults has been documented with the unconformity showing no time gap between Haseki and Hisarc›k Formations. Hac›hüseyintepe member has unconformity with the lavas that represent the second stage of Karaburun volcanics and laterally passes into the Karaba¤lar› member. The Karaba¤lar› member consists of green coloured lacustrine shoreface sediments which lie on the Aktepe succession with sublacustrine paraconformity. De¤irmentepe limestone transitionally lies on the top and it is the last member of the Karaburun group. Eflendere group lies on the Hisarc›k formation with regional scale angular uncoformity and presents the Late Miocene-early Early Pliocene(?) sedimentation grading from alluvial fan deposits of the Saip formation to lacustrine Çukurcak limestone. Calc-alkaline Karaburun volcanism which is represented with potassium rich andesitic products has three stages that laterally connected with the Early Miocene-early Middle Miocene deposition The first two stages have dual facies namely, pyroclastics at the base and lavas on the top. The first stage products are laterally discontinuous reference level that is separating Yeniliman limestone and Aktepe member. Second stage products are in/on the Aktepe member. The third stage lava flows are dated as K/Ar 16.0±1.3 Ma age which is thought to be located at the bottom of the De¤irmentepe limestone that is the last member of the Karaburun group
GLAUBERITE-HALITE ASSOCIATION IN BOZKIR FORMATION (PLİOCENE, ÇANKIRI-ÇORUM BASİN, CENTRAL ANATOLİA, TURKEY)
No full textTertiary Çank›r› – Çorum Basin is one of the biggest basin covering evaporitic formations in the Central Anatolia. During borehole drills carried out in Bozk›r Formation which contain Pliocene aged evaporites in the basin, a thick rocksalt (halite, NaCl) deposit was detected that consisting of glauberite (Na2Ca(SO4)2) interlayers (sabhka) synchronous with sedimentation. Rocksalt bearing layers in Bozk›r formation which was deposited in playa-lake – sabhka environment, where seasonal changes are effective, were first defined as Tuz member in this study. Bozk›r formation was divided into three zones in drillings carried out in sabhka – playa -lake transitional environment. From bottom to top, these are ordered as claystone-less anhydrite zone, rock salt-claystone-anhydrite-glauberite zone (Tuz member) and claystone-gypsum-less anhydrite zone. Rocksalt was cut in thicknesses reaching 115 meters within Tuz member. Rocksalt (playa-lake) which is mostly bedded and white, pale/dark gray colored is conformable with sedimentation and is low dipping. The level at which glauberite deposition within Tuz member is observed the thickest was defined as glauberite-mudstone zone. Glauberite mineral which is observed as disc and rosette shaped individual forms within mudstone dominant matrix was formed as a diagenetic mineral in saline mudflat environment (sabhka). In geochemical analyses carried out (XRD, XRF, SEM) it was detected that glauberite mineral had been crystallized following anhydrite mineral within matrix that includes complex crystal forms in sabhka environment, halite mineral had grown on glauberite mineral and it was sometimes observed in the form of fracture and crack infill. The glauberite mineral deposition which does not have an economical thickness is of great importance in ter
TECTONO - SEDIMENTARY EVOLUTION OF BUCAKKIfiLA REGION (SW KARAMAN) IN CENTRAL TAURIDES
No full textThe study area located in Bucakk›flla region in Central Taurides consists of rock units of the melange which form Bozk›r unit of the Tauride units and the overlying cover rocks. There are volcanic, ophiolitic and sedimentary rocks which generated in different environmental conditions. These rock groups comprise units which formed in Middle-Upper Triassic- Paleocene periods in Inner Tauride Ocean that had been opened between Tauride – Anatolide continents. Within the scope of this study, lithostratigraphic characteristics of Hu¤lu, Boyal› tepe (hill), Korualan nappes and cover rocks which form Bozk›r Unit and tectono sedimentary evolution of the study area was built up by paleontological and structural features. Due to rifting, which started in Middle Upper Triassicin the region, the products of the rift volcanism in rifting center and the carbonate deposition on margins of basin have occurred. Thecontinuation of extension which initiated rifting caused collapse in the basin in Middle Upper Triasic – Lower Senonian. Deep marine deposition has occurred at the center of basin, however pelagic and neritic limestones were deposited in basin margins during this time. The region has become compressed by the effect of a new tectonical regime which had been effective starting from Santonian. This compression caused new complexes to take place due to reverse faults and thrust. The formation of these complexes has continued until the end of Eocene period. However, there has not been observed any formation depending on the compression in post Paleocene. The nappes have moved southward by the effect of compression until Eocene. But then, these nappes could not advance forward anymore so, northward back thrusts took place as basin was closured andreached the collisional stage. Sequences which had become imbricated structures by back thrusts were subjected to collapsing by the stop of compression and the gravitational effect. All sequences in the imbricated structure were cut by dip slip normal faults and lacustrine basins were formed on fallen blocks. The formation of Early Oligocene terrestrial deposits in these lakes indicates that the collapse occurred in Oligocene or immediately before this time, and this allows the dating of new tectonical period. Early Oligocene deposits to become tilted by dip slip faults show that new tectonic period in the region has also continued after Oligocene