Bulletin of the Mineral Research and Exploration (BMRE)
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Petrography, mineral chemıstry and crystallizatıon conditions of cenozoic plutonic rocks located to the north of Bayburt (Eastern Pontıdes, Turkey)
No full textThe Eastern Pontides comprises of many intrusive bodies varying in composition, size and age from Paleozoic to Cenozoic. Those of especially Cenozoic aged ones are commonly observed in the southern part while are rarely exposed in the northern part of the Eastern Pontides. In this study, the petrographical and mineral chemistry properties of Çiçekli, Somarova, Sorkunlu, Şaşurluk, Aydıntepe, Kemerlikdağı and Pelitli plutons located to the north of Bayburt area are determined, and the crystallization conditions of the studied bodies were estimated by means of thermobarometer calculations. The studied plutons extend mostly NE-SW directions and are approximately ellipse in shapes. The contacts between the plutons and surrounding rocks are sharp, and plutons commonly contain mafic microgranular enclaves (MMEs) of different size. Petrographic and mineral chemistry studies reveal some disequilibrium textures reflecting magma mixing process. Based on modal mineralogy, the plutonic rocks are gabbroic diorite, diorite, tonalite, granodiorite and monzogranite in composition. The rocks have fine to medium granular, porphyric, monzonitic, poikilitic, myrmekitic and micrographic textures. The main minerals are composed of labradorite and albite (An68-02), magnesiohornblende and actinolite (Mg# = 0.6-0.9), diopside and augite (Wo44-46), clinoenstatite (En53-57) and Fe-Ti oxide minerals. Crystallization temperatures calculated from amphibole, biotite, clinopyroxene, magnetite and ilmenite minerals are 405 °C to 1161 °C, pressure values are 0.1 to 2.7 kbar, oxygen fugacity (log10 ƒO2) are -20 to -12. Estimation of water content calculated by using amphiboles is between 2.9 and 6.8%. Based on obtained data, it is suggested that the studied plutons have emplaced in shallow depths (~ 1-8 km).
DOI: 10.19111/bulletinofmre.42782
The neotectonics of NE Gaziantep: The Bozova and Halfeti strike-slip faults and their relationships with blind thrusts, Turkey
No full textIn the northeast of Gaziantep, east-west trending thrusts, northeast-southwest trending left lateral strike-slip faults and northwest-southeast right lateral strike-slip faults are located. They are typical features of the neotectonics of southeast Anatolia, Turkey. Detailed mapping of these structures and structural data obtained from fi eld studies indicate that east-west trending thrust faults and related fault propagation folds is post-Pliocene. The strike-slip faults that cut these structures should be younger than the thrust fault. On the other hand, the recent seismic activity in the southeast Anatolia (2011.10.23 – M=7.3 Van; 2012.06.14 – ML=5.5 Şırnak-Silopi earthquakes) shows that north-south compression is taken by both thrusting and strike-slip faulting. http://dx.doi.org/ 10.19111/bulletinofmre.40121
Palynology of the Kılçak formation (Early Miocene) from Central Anatolia: Implications for palaeoclimate and palaeoenvironment
No full textThe palynological analysis of the early Miocene successions of the Kılçak formation (Central Anatoia, Turkey) was carried out in order to reconstruct the palaeovegetation. The pollen spectra indicate a fl ora dominated by Pinus, co-dominance of Cupressaceae in one of the investigated successions, and lower percentages of trees such as Taxodioideae within Cupressaceae, Quercus deciduous type, Carya, Carpinus, Ulmus, Engelhardioideae, Salix, Alnus and Juglans. Herbs are represented by minor amounts of Poaceae, Amaranthaceae/Chenopodiaceae and Asteraceae. This flora indicates the presence of a Taxodium topogenous mire with a nearby riparian vegetation and broadleaved deciduous mixed forests developed in the surrounding distant mountainous areas. δ13C analysis shows that the vegetation was dominated by C3 plants. The Kılçak palynoflora reflects a humid, warm-temperate climate being compatible with the global warm conditions maintained during the early Miocene http://dx.doi.org/10.19111/bulletinofmre.39578
Mineral chemistry, whole-rock geochemistry and petrology of Eocene I-type shoshonitic plutons in the Gölköy area (Ordu, NE Turkey)
No full textThe Eocene intermediate to felsic plutons are widespread in varying sizes and compositions throughout the Eastern Pontides Orogenic Belt in NE Turkey. Of these, two monzonitic bodies (namely the Eriko Tepe and Göl Tepe Plutons) in the Gölköy (Ordu) area, extend nearly in the orientation of NW-SE and E-W and were emplaced into the Upper Cretaceous and/or Eocene volcanic and sedimentary rocks. Petrographically, the studied monzonitic plutons are compositionally fine to medium grained monzonite, monzodiorite and subordinate quartz-monzonite. They consist of plagioclase (An35-67), K-feldspar (Or61-96), quartz, clinopyroxene (Wo28-49En35-51Fs10-25), biotite (Mg#: 0.53-0.73) ± hornblende (Mg#: 0.65-0.82), Fe-Ti oxide with monzonitic, poikilitic, perthitic, rare antirapakivi and graphic textures. Mineral thermobarometer estimations imply that the plutons were crystallized in P-T conditions of mid to shallow crustal levels. Petrochemically, these monzonitic plutons show post-collisional, I-type, metaluminous (A/CNK=0.76-0.93) and shoshonitic features. The whole-rock major oxide and trace element variations suggest that fractionational crystallization played a significant role in the evolution of these monzonitic plutons. The primitive mantle-normalized trace element patterns of the studied plutons are similar to each other with enrichment in large ion lithophile elements, Th, Ce and negative Nb and Ti anomalies. Moreover, the chondrite-normalized rare earth element plots of the plutons show moderately enriched concave-shaped patterns (LaN/LuN=9.3-12.6) with negative Eu anomalies (EuN/Eu*=0.69-0.84), all of which imply plagioclase and clinopyroxene ± hornblende fractionations during their evolution. The geochemical data suggest that the monzonitic plutons have evolved from parental magmas derived from the melts of enriched lithospheric mantle in a post-collisional setting. DOI: 10.19111/bulletinofmre.37162
An ore adit planning with the help of three dimensional ore body modeling: A case study from Çulfa Çukuru Pb-Zn-Cu-Ag deposit
No full textÇulfa Çukuru Pb-Zn-Cu-Ag mineralization has occurred along the metamorphic and metamorphic-dacitic volcanic rock contacts of the Sakarya zone on the Biga Peninsula. The base metal mineralization (Pb-Zn-Cu-Ag±Au) developed along the contact and fracture planes of these rocks can be observed as veins, lenses and disseminated ore geometries in the calc-silicate rock assemblages. Base metal mineralizations are mainly controlled lithologically and are generally associated with recrystallized limestones. In this study, the surface and the subsurface were modeled using the topographical data and the geochemical data (%Pb and %Zn) collected from 42 boreholes of Çulfa Çukuru which is located 20 km South-Southeast of Kalkım (Çanakkale). The surface and the subsurface data were interpolated by Kriging and Inverse Distance Weighted methods, respectively. The intersectional areas of %Pb and %Zn modeling data obtained from this study were determined by dividing the areas above the cut-off grade into 4 different sectors (low, intermediate, high, and very high). Using the distribution of the intersections of these sectors, the possible adit lines were determined and also an interpreted map of the adit was drawn for 450 level. This modeling study helps to plan the ore adit to be opened in a mining area. Moreover, according to the important changing that may occur in conditions (e.g. fluctuations in metal prices or decreasing increasing costs), models can also be modified during operations. DOI: 10.19111/bulletinofmre.37251
The Hydrogeological investigation of Plajköy spring (Elazığ)
No full textPlajköy spring discharges at the close locations to the SE shore of Lake Hazar. Lake Hazar is a tectonic Lake in Elazığ city. Plajköy spring is a fault spring that is mainly recharging from the volcanites, dikes and blocky volcanosedimentary units of Middle Eocene Maden Complex. These units have gained secondary permeability and porosity related with the active tectonics that is effective in the studied area. The present catchment system of the spring could not collect the springs and leaks discharging from different points around the system. The discharge of the catchment is measured by specifi c volume method while the other springs’ and leaks’ is measured by using triangular weir. Before the discharge measurement of the leaks and the springs, they have been directed to a channel. The discharge of the present catchment system and the leaks have measured twice in a month during one year period beginning from October of 2012 to November of 2013. The discharge coeffi cient of the spring is calculated 1.33*10-3 day-1. Discharge coeffi cient of the spring depends on the geometry and intensity of the active fracture systems in the region. Calculated discharge coeffi cient indicates that the spring discharge is related with the narrow fi ssures, fractures and pores. The total volume of discharged groundwater in the real regime of the Plajköy spring is calculated as 52* 103 m3 during the period from 31st of March, 2013 to the 13rd of October, 2013 by Maillet formula. The spring water is Ca- Mg- HCO3 type water related with the chemical analyses. The chemical and microbiological analyses of the spring water are correlated with the drinking water standarts of Turkey TS 266 (TSE, 2005) and World Health Organization (2004), and it is seen that the spring water is suitable for drinking. The Plajköy spring will be used more effi ciently without exposed to pollution by the new catchment plan and protection zone map that are consequently proposed in the present study. http://dx.doi.org/10.19111/bulletinofmre.37676
The Naşa intrusion (Western Anatolia) and its tectonic implication: A joint analyses of gravity and earthquake catalog data
No full textThe gravity data gathered in and around the Simav Graben in Western Anatolia were reprocessed and reinterpreted by using the standard deviation fi lter and the Euler deconvolution. The joint evaluation of results from the interpretation of gravity data and seismological studies indicates the presence of new intrusive structures in the vicinity of Simav. The intrusion is located in the eastern margin of the graben and has a thickness of 12-15 km at 2.5-3 km depth below the surface. Numerous earthquakes recorded in the eastern part of the graben are associated with this intrusion. Besides, the multidimensional modelling study of the gravity data allowed us to display the Simav Graben, the fold of the Simav Fault, the intrusion named as Naşa, and the epicenters of earthquake within the same tectonic frame. All tectonic structures were marked on the three dimensional relief model. http://dx.doi.org/10.19111/bulletinofmre.41059
Investigation of thermal and mechanical behavıors of construction materials obtained from some natural stone waste
No full textIn this study, thermal and mechanical behaviours of composite building materials obtained from different kinds of natural stone wastes were investigated. First of all, XRD, chemical and grain size distribution analyses were carried out to identify the natural stone wastes to be used. 60% granite (magmatic), 35% recrystallized limestone (metamorphic) and 5% pure aluminium oxide (Al2O3) materials were used in the prepared mixture. The prepared mixture was shaped in a steel mould 75x20x50 mm in size by adding 7% shaping water and fired at 1140 ° C, 1150 ° C and 1160 ° C. Following that XRD analyses, colour determination, water absorption coefficient, bending strength, Young’s Modulus, bulk density, apparent density and open porosity tests were performed on the samples. According to the XRD analyses results gehlenite, anorthite and wollastonite phases were detected. In accordance with the results of other experiments and analysis, it was found that bending strength, Young’s Modulus and mass density values have increased, but on the other hand water absorption coefficient, apparent density and open porosity values had decreased after the firing process. DOI: 10.19111/bulletinofmre.42831
Post-Glacial Terraces of The Marmara Sea and water exchange periods
No full textSemi-enclosed Marmara Sea is a passage between the Aegean Sea (Northeastern Mediterranean Sea) and the Black Sea. The Marmara Sea is connected to the Black Sea and the Aegean Sea through the İstanbul Strait (Bosphorus) and Çanakkale Strait (Dardanelles), respectively. Despite the fact that the late Pleistocene-Holocene connections between the seas have been explored by many scientists, there are still uncertainties about the nature and timing of the connections. Within the scope of this study, a new approach has been displayed for post-glacial connections between the Black Sea, Marmara Sea, and the Aegean Sea. This study is based on 80 shallow seismic reflection lines, multibeam bathymetric data and 15 short gravity cores collected from the northeastern shelf of the Marmara Sea (between Silivri and Golden Horn). The sea bottom and sub-bottom morphology have a highly chaotic structure at the exit of the Büyükçekmece/Küçükçekmece lagoons and further east near the Marmara- İstanbul Strait junction. This chaotic bottom and sub-bottom surface morphologies are mainly controlled by the structure of the basin, current regime of the shelf, coastal drainage systems and by the sea/lake water level changes controlled by climate and the sill depths of the two straits, which in turn determined the water exchange between the seas. The sedimentological interpretation of the seismic reflection profiles and core sediments have allowed us to distinguish five stratigraphic units (S1-S5) and four sedimentary layers (A-D) over the acoustic basement. The lower stratigraphic unit and sedimentary layer are separated from the overlying acoustic basement by a chaotic to parallel and by a high amplitude seismic reflector. Seaward dipping units of the acoustic basement are inferred to be the seaward continuation of the Oligocene–Upper Miocene units widely exposed on land. The presence of three different marine terraces distinguished (T1-T3) along the northeastern shelf of the Marmara Sea have been associated with the six different curves of the post-glacial sea-level changes. From statistical point of view, the most significant terraces occur from -78 m to -80 m (T1), -58 m to -62 m (T2) and -28 m to -32 m at (T3). Considering the global sea level curves, these terraces can be dated 9.25, 12.25 and 13.75 Cal kyr BP, respectively. DOI: 10.19111/bulletinofmre.40120
Mineralogical findings from manganese deposits in the Artova Ophiolite Complex, Derbent-Eymir area, Yozgat, Turkey
No full textThe Artova Ophiolitic Complex (AOC), which formed in association with Alpine Ophiolites, is exposed in the NE part of central Anatolia, in the interior of the central Black Sea region and within the borders of Çorum and Yozgat. The Derbent-Eymir manganese- oxide deposit under investigation occurs within this ophiolitic complex. The mineral association in Derbent ore is composed chiefly of pyrolusite, manganite and lesser amounts of ramsdellite, magnetite and goethite. Calcite is the main gangue mineral. The mineral association in Eymir ore is represented by pyrolusite, braunite, neltnerite, jacobsite, psilomelane and trace amount of limonite accompanied by some gangue minerals such as quartz and calcite. Electron microprobe analysis was carried out on pyrolusite, braunite and psilomelane minerals. While pyrolusite from Eymir has higher Si, Al, Mn and Ca, pyrolusite from the Derbent ore has lower Fe, K and Ba contents. Pyrolusite in the Eymir ore has higher Si, Al, Mn and Ca (10.28-7.06; 3.19-1.28; 87.98-81.88; 2.38-1.97 respectively) and lower Fe, K and Ba (0.31-0.16; 0.02-0.00; 0.07-0.00 respectively) contents in comparison to pyrolusite in the Derbent ore. Element variations in core-rim zones of spherical pyrolusites and manganite crystals elongated towards the gangue are quite noticeable. Both Eymir and Derbent ore deposits are low-temperature hydrothermal deposits. Geochemical variations recorded in various manganese minerals are found to be strongly dependent on the changes in pH and temperature of the ore-forming solution and distance to the spreading center. http://dx.doi.org/10.19111/bulletinofmre.33424