Bulletin of the Mineral Research and Exploration (BMRE)
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Uncertainty-volume fractal model for delineating copper mineralization controllers using geostatistical simulation in Nohkouhi volcanogenic massive sulfide deposit, Central Iran
No full textThe aim of this study was to delineate copper mineralization controllers in Nohkouhi volcanogenic massive sulfide (VMS) deposit by using geostatistical and fractal simulation. In this study, concentration-volume (C-V) fractal model has been used to indicate various copper populations related to different host rocks and copper minerals. Accordingly, uncertainty-volume (U-V) fractal model was applied to probability values achieved through sequential indicator simulation (SIS). Copper ores of Nohkouhi deposit including chalcopyrite and malachite were simulated in 30 realizations. The U-V fractal model obtained by using a probability map was divided into four probability zones (high, moderate, low, and very low) for copper minerals. Furthermore, copper grades were simulated for 10 times by sequential Gaussian simulation (SGS). Combination of C–V and U-V fractal modeling resulted in a hybrid method which could be properly employed to determinate various mineralization zones based on the relationship between quantitative (e.g.copper grade) and qualitative (e.g. copper minerals) variables. Moreover, integrating the results of C–V and U-V fractal modeling with the most frequent occurrence of rock type modeling helps identify copper mineralization controllers in a VMS deposit.
https://doi.org/10.19111/bulletinofmre.49575
Integration of the GNSS method and borehole camera to model the resulting spherical cavity generated by the main charge blast in clay
No full textA depth camera was used to record the spherical cavity which occurred during blasting in clay soil. For this purpose, the integration of the Global Navigation Satellite System (GNSS) method was applied in addition to the depth camera and the laser, to determine the resulting spherical cavity. The expanded spherical cavity, formed after the blasting of the explosive charge in the bottom of the borehole, was measured by a depth camera-laser system. The GNSS measurement method was instrumental for obtaining the coordinates of the borehole. The Multichannel Analysis of Surface Waves (MASW) measurement method was also used during the study. Shear wave velocities (VS) were calculated using MASW method to evaluate the dynamic properties of the clay soil along the in-situ profiles. The results obtained in this way, showed that there was an increase in the stiffness of the surrounding clay soil after blasting. The main objective of the study was to determine the resulting shapes and volume of the occurred cavities. For a more detailed graphical interpretation, an application was developed, which calculates the coordinates, shape and volumes of the formed spherical cavity. https://doi.org/10.19111/bulletinofmre.72639
Oligocene molasse sedimentation in the Central Taurides: Records of the onset of extensional tectonic regime
No full textThe lacustrine units have been deposited in the Ermenek, Bucakkışla, Korucuk and Çamlıyayla basins in the Central Taurides since early Oligocene. In this study, structural features and stratigraphical properties of Oligocene basins have been described in detail and the lacustrine units have been dated. Regional geological interpretations have been made by using tectono-stratigraphic and age data of the basins. Lacustrine Oligocene sedimentation in these basins, which were opened on the tectonic units of Taurides due to normal faults, constitute the first records of the sedimentation occurring under the extensional tectonic regime after the orogeny of the Central Taurides. All the pre-Oligocene units that had been emplaced in the region due to a north-south compressional movement in the Central Taurides, continued to be compressed until the end of Eocene, and completed their orogenic development as napped structures. The bedrock units, reaching the maximum elevation, have been subjected to “orogenic collapse” due to the strain or gravity forces as a result of an interruption or termination of the compression which lasted until the end of Eocene. Thus, “orogenic collapse” basins have started to be formed in the Central Taurides since Oligocene. The orogeny and the compressional tectonic regime forming the Taurides lasted until late Miocene in the Eastern Taurides. On the other hand, extensional basin formation since early Oligocene on the Taurus units, which had been emplaced in the region due to nappe tectonics, indicates that a new tectonic period has started in the Central Taurides. https://doi.org/10.19111/bulletinofmre.68121
An overview of the current seismicity of the Sultandağı Fault Zone (Afyonkarahisar-Konya, Western Anatolia)
No full textWestern Anatolia is one of the most seismically active regions in Turkey. The high seismic activity is a result of a complex tectonic deformation dominated by the N-S extensional tectonic regime in Western Anatolia. This tectonic deformation is also a result of the relative movement of the African- Arabian plates towards the north, which causes the Anatolian plate to shift 2.5 cm per year towards W-SW. One of the largest fault zones in the Western Anatolia, Sultandağı Fault Zone (SFZ) has a northwest-southeast trend. SFZ, approximately 120 km long, is an important tectonic structure, which produced three major earthquakes (Mw\u3e 6.0) between the years of 2000 -2002. Therefore, the most significant goals of this study were to monitor the micro-earthquakes along SFZ, to enrich the current seismic network and to increase the earthquake detection threshold in the region (Mc \u3c2.5). Within the scope of the study, 3 digital broadband earthquake stations were installed in the region. The analysis of the data obtained in the research indicated that the central and western parts of SFZ are active and there is intense seismic activity especially in the vicinity of Sultandağı, Çay, Çobanlar, and Afyonkarahisar. Fault plane solutions revealed that the earthquakes in the region generally ocur with normal faulting with oblique components. Seismic stations installed within the scope of the study contributed positively to the increase of the sensitivity (Mc = 1.3) of the earthquake detection threshold (Mc) in the region and increased the detection capacity. https://doi.org/10.19111/bulletinofmre.72179
Emplacement conditions of magma(s) forming Jurassic plutonic rocks in Gümüşhane (Eastern Pontides, Turkey)
No full textIn this study, the petrography, mineral chemistry and crystallization conditions were reported for the Alemdar and Işıkdere plutons located in limited areas in the south of the Eastern Pontides. These plutons, which trend mostly in NE-SW directions, were emplaced by cutting the Early- Middle Carboniferous-aged Gümüşhane Granitoid and Early-Middle Jurassic Şenköy formation. Petrographically, the studied plutons are compositionally fine to medium grained quartz-diorite, quartz monzodiorite and tonalite. The rocks in the plutons have granular, poikilitic, monzonitic, graphic and rare porphyritic textures with consist of plagioclase, (An05-92), hornblende (Mg# = 0.52- 0.81), biotite (Mg# = 0.32-0.67), orthoclase, quartz and Fe-Ti oxide. According to thermobarometric calculations, plutons have crystallization temperatures, pressures and oxygen fugacity values ranging from 541°C to 938°C, 0.1 to 4.4 kbar, and -23 to-12, respectively. The estimated water content calculated from amphibole is between 4.4 to 7.8%. It can be concluded that the studied plutons were emplaced at mid to shallow crustal depths (~4-15 km).
https://doi.org/10.19111/bulletinofmre.64980
A laboratory-scale investigation on freezing-thawing behavior of some natural stone samples manifactured in Turkey
No full textIn the study, the changes in the mechanical properties of the natural stone samples, which had been obtained from different regions of Turkey, before and after the freeze-thaw test were examined. Within the scope of the study, 17 different natural stone samples were used and, after chemical and mineralogical-petrographical properties were determined. Water absorption at atmospheric pressure, real density, porosity, and uniaxial compressive strength tests were performed before and after freezing-thawing. The freezing and thawing test has been performed using TS EN 12371 standard from -12 °C to +20 °C in 56 cycles (2 cycles = 24 hours). After the test, the samples were subjected to uniaxial compressive strength test in order to identify the changes of the compressive strength values. The results of the physical and mechanical tests on these samples were evaluated by grouping according to chemical and mineralogical-petrographical properties of natural stones. It was aimed to determine which natural stone samples are resistant to freeze-thaw, and can be used in external cladding applications according to the findings obtained from the study. https://doi.org/10.19111/bulletinofmre.74648
An approach for the application of energy-based liquefaction procedure using field case history data
No full textThis paper presents an overview to the applicability of the “energy-based liquefaction approach” with regards to the new developments in the subject. The method involves comparing the strain energy for the soil liquefaction (capacity) with the strain energy imparted to the soil layer during an earthquake (demand). The performance of the method was evaluated by using a large database of SPT-based liquefaction case history. The energy-based method and the more commonly used stressbased method were compared in their capability to assess liquefaction potential under the same damaging historic earthquakes and geotechnical site conditions. In the procedure, the predictive strain energy equations were used to estimate the capacity energy values. These empirical equations have been developed based on the initial effective soil parameters. As for the energy of any given strong ground motion, it was computed from a velocity-time history of the ground motion and the unit mass of soil through utilization of kinetic energy concepts. The proposed energy-based method has effective way in evaluating the liquefaction potential based on the seismological parameters, contrary to the stress-based approach, where only peak ground acceleration (PGA) is considered. https://doi.org/10.19111/bulletinofmre.67762
Investigation on geoarchaeological structure of ancient ports in the Lycia Region
No full textThe effects of geological events that occurred in ancient times, on ancient cities are undeniably great, so geoarchaeology has become an important mutidisciplinary science. Using geological methods in archaeological researchs offers a much more comprehensive understanding for history. Today, the methods of remote sensing and geographical information systems have facilitated archaeological researches to a greater extent than before. In this study, Phaselis, Andriake and Patara ancient cities were investigated. In the research, help was obtained from satellite images as a method. By comparing the ancient coast line and the modern coast line, it is tried to be understood to what extent the sea level change occurred.
https://doi.org/10.19111/bulletinofmre.54554
Estimation of the compaction characteristics of soils using the static compaction method
No full textGround improvement using mechanical stabilization is commonly applied by performing the standard Proctor compaction test, which requires a significant quantity of soil, usually obtained from open pits. A static compaction test is an alternative laboratory compaction test. Although researchers have shown that the results of miniature size static compaction tests are comparable with that of standard Proctor tests in terms of the maximum dry density and the optimum water content, no attempt has been made to compare the two fundamental properties of the compacted soil: undrained shear strength and hydraulic conductivity. The scope of this investigation was to estimate the level of static compaction energy required to (1) obtain a compaction curve similar to that of the standard Proctor test; (2) reconstruct compacted soils using the standard Proctor and static compaction tests at the optimum water content; and (3) compare the undrained shear strength and hydraulic conductivity of compacted soils. The compacted soils at the predetermined energy level were subjected to hydraulic conductivity tests using the rigid-wall falling-head permeability method. Undrained shear strength tests were performed by employing a high-capacity laboratory vane shear apparatus on compacted samples of both the standard Proctor and static compaction tests. The present investigation revealed that the static compaction test, requiring about only 10% of the soil necessary to perform the standard Proctor method, provides comparable results in regard to hydraulic conductivity and undrained shear strength.
https://doi.org/10.19111/bulletinofmre.60387
Rare earth element contents, geochemistry of soil samples between Burdur and Isparta region and assessment of their origin
No full textThis study was carried out in 5 locations between Burdur and Isparta in the inner southern part of Isparta Bend. The study aims to determine the rare earth element (REE) concentrations in the soil samples collected from the field and to interpret the origin of the high concentrations detected. In this context, a total of 104 samples were collected from Canakli Village (19 samples), Cobanisa Village (34 samples), Kuyubasi Village (17 samples), Kuzca Village (17 samples), and Yilanli Village (17 samples) in the study field. The average ∑REE (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) concentration values of the samples by their locations were determined to be Çobanisa (821.88 ppm) \u3e Yılanlı (723.39 ppm) \u3e Kuzca (692.54 ppm) \u3e Çanaklı (583.46 ppm) \u3e Kuyubaşı (484.04 ppm). The average light rare earth element (LREEs) concentration (such as La 229 ppm, Ce 378 ppm) of the samples collected from all locations is higher than the average rare earth element concentration in the Earth’s crust. According to the Chondrite-normalized Rare Earth Elements diagram, the distributions of the rare earth elements in these 5 locations were determined to be very similar and the high concentrations were considered to occur under similar conditions or originated from similar sources. In this context, based on the idea that Gölcük Volcanism may be the source of high concentrations, the rare earth element concentrations of Gölcük Volcanism in the northwest of the zone were compared to those taken from the study area and the values were found to be consistent with each other.
https://doi.org/10.19111/bulletinofmre.68792