Bulletin of the Mineral Research and Exploration (BMRE)
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Production of rare-earth oxides from Eskişehir-Beylikova complex ores
No full textIn this study, the production technology of barite, fluorite, rare-earth elements, and thorium-bearing rare-earth oxides from the Eskişehir-Beylikova were investigated, and the processes that can be used in the production of thorium-free mixed rare earth oxides were tested. The applied processes are roasting, leaching, solvent extraction and precipitation methods, respectively. After all studies, the optimum roasting temperature and roasting duration are determined as 600 °C and 1 hour. In the extraction stage, the highest leaching efficiency is achieved with 5 M HCl, 1-hour leaching duration, 1/3 solid/liquid ratio and 35 °C leaching temperature. While methyl tri C8-C10 ammonium chloride (Adogen 464) is used for the removal of iron from produced solution, di-(2-ethylhexyl) phosphoric acid (D2EHPA) is used for the removal of thorium. As a result of solvent extraction studies, the solution containing rare earth elements is precipitated under optimum conditions. After precipitation, the product contains 99.65% rare earth oxides
Groundwater potential mapping using the integration of AHP method, GIS and remote sensing: a case study of the Tabelbala region, Algeria
No full textRecently, groundwater resources are assessed and evaluated using Geographic Information System (GIS) and remote sensing technologies due to their effectiveness and wide spatial coverage. This work aims to identify groundwater potential areas in the Tabelbala region which lies in the Algerian desert in order to help for the solution of water resources shortages. GIS and remote sensing are employed in the preparation of the controlling factors such as lithology, lineaments, drainage network, slope, land use/land cover, topographic wetness index, and elevation. Statistical Analysis, as well as interpretation of remote sensing data, allow the extraction of important features about the study area and its characteristics. The prepared layers are combined with multicriteria analysis to identify the groundwater potential zones (GWPZs) based on their statistical weights. To validate the conducted work, 222 wells/boreholes are collected and prepared to assess the potential areas
Geothermal gradient variation in the Büyük Menderes Graben: implications for geothermal potential of the graben, Western Anatolia, Türkiye
No full textThe Büyük Menderes Graben (BMG) is an E-W oriented active extensional geothermal basin within the Menderes Massif, a metamorphic core complex, in Western Anatolia, Türkiye. 1500 (megawattsenergy) MWe of installed geothermal capacity for power production exist as of December 2019 in Western Anatolia, mostly generated in the BMG. While the BMG is a vastly producing geothermal resource, it is predicted that it has higher production potential. However, other studies do not include field scale 3D geologic models or geothermal gradient maps. This study aims to first quantitatively test the geothermal gradients in the Aydın-İncirliova-Osmanbükü Geothermal Field (IGF), then map the information. This study also aims to compare the IGF with a neighboring geothermal field. To complete this study, information from stratigraphic columns, bottom hole temperatures, and continuous temperature logs from 13 geothermal wells is utilized with Leapfrog Geothermal to create 3D models of the geology and subsurface temperature distribution. Then, isothermal contour maps of the field are created. The geologic modeling suggests that synextensional deposition has occurred within the graben. The temperature modeling suggests both that thermal breakthrough may have occurred in the field, and that the IGF has a higher geothermal gradient than the nearbyGermencik Geothermal Field
Evaporate salt exploration by two dimensional (2D) seismic reflection method: Ankara- Polatlı region, Türkiye
No full textThe presence of the evaporate salt zone in Ankara-Polatlı region has been determined by the drillings. It is thought to be the largest reserve in Türkiye. The seismic reflection method was used to determine the top-bottom levels of the zone; its depth; its thickness and extent boundaries; the horstgraben structures; base depth and tectonic movements affecting the study area. Data were collected on three seismic lines. The near-surface tomographic velocity sections were compatible with the top-of-the-zone depth observed in the drillings. As a result of the study, the depth and thickness of the top-bottom of the zone were determined along the lines. Within the scope of the study, a combined interpretation was made on the lines by using gravity and seismic data. The extent of the ore zone was determined only in the E-W direction section, but not in the north-south direction lines since they are outside the license area and the seismic lines. The closest point of the evaporate zone to the surface is approximately 150 m, the deepest point is approximately 310 m, the average thickness is approximately 100 m and the maximum thickness is 185 m
Comparative analysis of water and carbon dioxide injection for the thermohydraulics of an EGS project in Dikili Geothermal Field, Türkiye
No full textA comparative numerical analysis of the thermohydraulics of an enhanced geothermal system (EGS) project in Türkiye in Dikili area is presented. The fractured granodiorite is modelled as porous media, utilizing the numerically suggested data of other authors for the corresponding hydraulic characteristics. As the heat transmission fluid, two different mediums are alternatively considered. These are the more classical medium, water and the supercritical carbon dioxide (sCO2). Transient calculations are performed for a time period of twenty years, comparing the temporally developing results obtained for water and sCO2 with each other. Based on modeling parameters and assumptions, higher production temperatures are observed with sCO2, in comparison to water, implying an advantage for sCO2 usage as a working fluid in EGS. This is accompanied by the further advantage of a lower pressure drop for sCO2. On the other hand, the temperature advantage is relativized by the lower specific heat capacity of sCO2 causing a decrease in the production thermal power. In general, the present results are found to be encouraging for a further and more detailed analysis of the employment of sCO2 as working fluid in EGS
The importance of Confocal Raman Spectroscopy and mineral chemistry studies in the magma crystallization processes: Strandja Intrusives, NW Türkiye
No full textThe Strandja Massif cropping out in NW Turkey is cut by Late Cretaceous intrusives. These are called Strandja Intrusives and they are felsic and mafic coeval intrusives. Felsic intrusives consist of granite, granodiorite, quartz monzonite and syenite, while mafic intrusives consist of diorite and gabbro composition. Main composition of felsic intrusives consists of quartz, alkali feldspar, plagioclase, biotite, amphibole ±pyroxene mineral association, while main composition of mafic ones consists of plagioclase, biotite, amphibole ±pyroxene ±olivine mineral association. Amphiboles hydrated double-chain mineral of the Strandja Intrusives observed in all rocks used as an index mineral in this study to understand the petrological evolution of the rocks. According to Confocal Raman Spectroscopy studies amphiboles were actinolite type and exhibited similar spectrum and results of mineral chemistry reveals that they were calcic/Mg-hornblende types. According to geothermobarometer calculations, amphiboles crystallize in felsic intrusives at a pressure range of 0.49-0.94 kbar and a temperature of 757.52-814.49oC temperature at a depth of approximately 1.34-4.93 km, while in mafic ones at 2.59 kbar pressure and 892.82oC temperature at 9.97 km depth. Different temperatures-depth conditions and overlaps in Raman shift obtained from amphiboles indicate that these intrusives are derived from different sources but crystallized in the same environment
Geothermal power corridor-connecting the Middle East Countries
No full textThe Middle East economy and life depend on imports, be it food, water, or energy, despite each country in the region having enormous energy resources to exploit and reduce dependency on countries outside the region and develop a socioeconomic model of regional cooperation and synergy. An estimated 371 TWh of electricity available from geothermal energy resources can be utilized by these countries to support basic needs and be free from food-energy-water imports by sharing their energy resources. The total amount of CO2 emissions from these countries is currently 945 x 106 kg, so these countries can further earn about 92 million euros from carbon savings, by using geothermal energy along this corridor. This amount can be utilized for augmenting the energy supply from geothermal sources. In this work, the available geothermal resources are evaluated, and suggestions are made how this energy can be best utilized for peaceful existence and cooperation in the region
Geology of the Kurucaşile - Cide region, NW Türkiye
No full textThe lowest unit of the Cide-Kurucaşile region is the Carboniferous coal-bearing terrestrial sediments. Permian aged terrestrial Çakraz Formation and the Triassic lacustrine Çakrazboz Formation unconformably overlie the Palaeozoic sequence. Dogger-aged Himmetpaşa Formation represents a short-period marine invasion. The transgression started in the Kimmerician has led to the development of a carbonate platform, which has risen and demised after the Berriasian. A second carbonate platform, much more limited than the previous one, developed in the Late Barremian, and then the whole region deepened. The Cenomanian is a period of regional uplift and erosion. The first effective volcanic activity in the region started in the Middle Turonian. During this period, Extensional faults coeval with the deposition, and the region gained an irregular topography. In the Middle-Late Santonian, the volcanism became silent for a while, the region rapidly subsided and became a completely deep marine environment. These events indicate that the continental crust of the region was broken up and the oceanic crust began to develop in the Western Black Sea back-arc basin. In the Campanian, the volcanism reactivated, but ceased after a short time, leaving its place to pelagic sediments forming the southern passive continental margin deposits of the Black Sea. In the Maastrichtian, the region was tectonically compressed and uplifted and provided turbiditic material to the Black Sea in the north and the Devrek Basin in the south. Siliciclastic turbidites have been deposited in the region until the Middle Eocene. At the end of the Middle Eocene, following the uplifting of the entire region and the destruction of marine environments, the north-vergent thrusts were developed due to intense compression and the region became a fold-thrust belt. https://doi.org/10.19111/bulletinofmre.88465
Estimation of blast vibrations by numerical modelling and signal analysis
No full textSeismic waves carry all the geological and geotechnical characteristics of the units they pass along the route they travel on. Therefore, seismic waves can be called the signature of the route it passes through. If the blasting point is considered as source, blast-induced seismic waves measured at a certain distance from the source can be revealed and this form can be integrated into the dynamic numerical model, the effects that will occur at any point of the model can be predicted. In this study, seismic waves induced from single-hole blast and a group blast consisting of holes with the same characteristics as a pilot blast hole were obtained using particle velocity data obtained from seismographs at certain distances and integrated into the numerical model. The data processing technique used is to estimate the theoretical group blasting data from the pilot data according to the linear superposition principle and compare with the real group blasting data to determine the nonlinear behavior effect on the blast source from the difference. When the results were examined, it was observed that the numerical model results and field measurements coincided. The results of this study will make a significant contribution to the science of rock engineering. https://doi.org/10.19111/bulletinofmre.106694
The new age data and pre-Paleogene stratigraphy of the Kırşehir Massif, Central Anatolia
No full textThe metamorphics belonging to the Kırşehir Massif, which form the pre-Paleogene basement units in Central Anatolia around Kırşehir, are formed from bottom to top by conformable and transitional Late Devonian Kalkanlıdağ, Carboniferous-Early Permian Kervansaray and Late Permian Bozçaldağ formations and by the unconformably overlying Triassic Demirtepe and Jurassic- Cretaceous Saytepe formations. The sedimentation age of 237 Ma were obtained from the clastic zircons in the quartzites of the Demirtepe formation by the U/Pb method, and the metamorphism age ranges from 94.5 Ma and 83.7±3.3 Ma from the metabasites from the Whole Rock by the 40Ar/39Ar method. The Kasımağa and Sırataşlar formations within the Çiçekdağı Nappe belonging to the northern branch of Neotethys, which were tectonically emplaced over these units and the Turonian- Santonian Kargınkızıközü formation, which were the product of ensimatic island arc magmatism, were distinguished. The metamorphics and the Central Anatolian plutonic rocks, which cut the overlying ophiolitic rocks, were differentiated according to their composition, origin and age, and ranges from 71.9±1.7 Ma from the Baranadağ pluton; ranges from 84.0±1.9 Ma and 71.9±7.2 Ma from the Çayağzı pluton; ranges from 69.1±1.2 Ma by the40Ar/39Ar method, and 65.3±1.1 Ma were obtained from the Buzlukdağı pluton by the U/Pb method. The age ranges from 79.1±1.2-68.2±1.2 Ma and 74.5 Ma were obtained from the whole rock by 40Ar/39Ar method from trachyandesites belonging to the Kötüdağ volcanics, which are surface-semi-depth rocks of granite, monzonite and syenite composition plutonic rocks. The cover units overlie all these units with an angular unconformity. https://doi.org/10.19111/bulletinofmre.93005