Bulletin of the Mineral Research and Exploration (BMRE)
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Gold deposits and mineralization studies: a 2018-2022 Scopus-based bibliometric analysis
No full textGold is an important source of economic development and international relations. The accumulation of this element and the formation of deposits is an urgent research problem. The variety of types of deposits, conditions of their formation, and methods of deposit development are of interest to many researchers. Thus, in order to understand the demand for this area, a bibliometric analysis was carried out using the keywords “gold deposits” and “gold mineralization” for a five-year period. The database was acquired from the Scopus and included 793 articles from 77 countries. Statistical analysis was done using the VOSviewer and Mapchart software. Among top publishing countries China, Australia, and Canada took the highest ranks. Top 3 authors stand out as having a high H-index, which indicates their high qualifications in this field. The most popular journal publishing these studies is Ore Geology Review with 259 publications. However, the most cited articles are published in Mineralium Deposita, Economic Geology, Geological Journal, Gondwana Research, Earth-Science Reviews, Geoscience Frontiers, and Geochimica et Cosmochimica Acta. All of these journals are related to Earth and planetary sciences. The large gold mining provinces of China, Australia, and Canada are a key factor in the high publication rate among researchers
Magnetic inversion modeling of subsurface geologic structures for mineral deposits mapping in southeastern Nigeria
No full textMagnetic inversion techniques have been implemented to infer the extension and geometry of magnetic structures and also evaluate its influence on mineralization within Abakaliki and its environs, southeastern Nigeria. The modeling approach considers the techniques of threedimensional (3D) magnetic data inversion, Euler deconvolution, analytic signal inversion, Enhanced Local Wavenumber (ELW) Technique and Particle Swarm Optimization (PSO) to estimate source parameters and compare results. Model solutions were interpreted to represent possible geologic units with varying trends, housing mineralization within the study region. Results from inversion computation over some active mine locations show subsurface bodies with magnetic susceptibilities \u3e0.00188 SI. Model results also show structural sources with almost 5.5 km depth extension, stretching 18 km in the EW direction at Ngbo – Ekerigwe location. This could imply significant mineral deposits at the location. Inversion of both magnetic anomaly and analytical signal enabled derivation of the actual subsurface structures in the region, with most of the structures appearing as dykes with depths ranging from 0.2 – 1.8 km at most of the mining sites. Location and depths of some of the modeled intrusions have been corroborated with the active on-site mines. The delineation of mineralization structures by this study would guide systematic exploration in the region
Active tectonics of western Kosovo: Insights from geomorphic and structural analyses
No full textKosovo is located in a key position in the central-west part of the Balkans providing an opportunity to understand the far-field effects of distributed intracontinental deformation caused by the Aegean extension in the south and Adriatic compression in the west. It is also situated along the NE-SW trending Shkodër-Pejë transverse zone, where the Dinarides and Albanides-Hellenides orogenic belts are juxtaposed. While the instrumental seismicity of Kosovo indicates the activity of this fault zone and many others, the active faults in the country were not discussed in detail in the current literature. In this study, we analyzed both the geomorphic and structural features of major mountain front faults in western Kosovo (i.e., Pejë, Istog, Krojmir, and Prizren faults) to reveal the relative assessment of their activities and kinematic characters. Geomorphic and morphometric analyses of all the studied four different mountain fronts indicated high activity and tectonic uplift rates of over 0.5 mm/a. On the other hand, according to the collected kinematic data from the observed fault planes, the studied faults are mainly of normal character representing a dominance of NWSE- directed extension in western Kosovo, which is most probably caused by the rollback of the subducting slab in the Hellenic trench
Mineral chemistry, petrography and crystallization conditions of the Middle Eocene Kazıkbeli Pluton (Eastern Pontides, NE Türkiye)
No full textThe Eastern Pontides host a diverse suite of plutonic rocks spanning a wide range of ages and compositions. Among these, the Middle Eocene Kazıkbeli pluton, located in the Kürtün district of Gümüşhane, stands out due to its distinctive petrological characteristics. This study aims to unravel the petrological implications of petrographic and mineral chemical data to determine the physicochemical conditions (temperature, pressure, oxygen fugacity) under which the Kazıkbeli magma crystallized and was emplaced. By integrating mineral chemical data, we seek to quantify emplacement pressure, crystallization temperature, and oxygen fugacity. A comprehensive understanding of the genetic relationships and physicochemical properties of the Kazıkbeli pluton rocks, as determined through geological, petrographic and mineral chemistry, is crucial for elucidating the geological evolution of the Eastern Pontides. The Kazıkbeli Pluton exhibits a predominant NE-SW orientation and encompasses an area of roughly 46 km². Modal mineralogical analysis reveals a compositional spectrum ranging from gabbroic diorite to monzogranite, with granodiorite and tonalite being the most prominent rock types. Textural variations encompass fineto medium-grained, porphyritic, poikilitic, and occasionally graphic textures. The primary mineral assemblage of the pluton comprises plagioclase, orthoclase, quartz, amphibole, biotite, and Fe-Ti oxides. Accessory minerals include zircon, apatite, sphene, and allanite. Plagioclases are labradorite to oligoclase (An26 to An66) in composition. K-feldspar minerals exhibited an orthoclase composition (Or80 to Or97). All amphiboles belong to the calcic amphibole field and exhibit a magnesio-hornblende (Mg#=0.63-0.73) composition. Biotites crystallized as solidified melt products with compositions between annite and phlogopite endmembers, plotting close to the magnesium-rich (Mg#=0.52- 0.58) end of the phlogopite solid solution series. Calculated crystallization temperatures derived from amphibole and biotite data range from 712°C to 824°C. Pressure estimations calculated using amphibole-plagioclase, amphibole and biotite suggest a range of 0.04 to 2.06 kbar. Oxygen fugacity (ƒO2) values calculated using amphibole and biotite fall between -12.5 and -16.1. Amphibole-based water content estimations indicate a range of 3.7% to 5.7% for the pluton. Biotite compositions within the studied Kazıkbeli pluton rocks exhibit characteristics suggestive of a potential mantle origin. Geobarometric calculations based on mineral chemistry data with geological and petrographic features indicate the emplacement of the Kazıkbeli Pluton at relatively shallow depths within the crust (~1 to 8 km)
Evaluation of the tectonic activity of faults with mineral alterations: a case of the East Anatolian Fault-Palu segment, Türkiye
No full textPalu segment is a part of the East Anatolian Fault Zone (EAFZ), the most important active leftlateral strike-slip fault system in Turkey, and there are different mineral alterations in this zone. The study tested the spatial relationship between tectonic activity and mineral alterations with the Getis-Ord Gi* statistic in and around the Palu segment. Mineral alterations at the pixel level were determined from ASTER images by Ratio, Relative Band Depth (RBD), Mineral Indices, CROSTA, Constrained Energy Minimization (CEM), Mixed Tuned Matched Filter (MTMF) methods. According to the results, the spatial distribution of alteration minerals extending parallel to tectonically active fault lines and/or partially bounded by faults in the area. RBD, Mineral Indices, CROSTA, CEM, and MTMF image processing algorithms applied in the study gave consistent results in the spatial determination and mapping of mineral alterations in the study area. At 99% and 95% confidence intervals, statistically significant cold spot clusters indicate the proximity of alterations to faults concentrated around fault lines. This degree of clustering of mineral alterations indicates regions with high alteration rates close to fault lines and areas with tectonic activity along fault lines
Modelling and computation of gravitational attraction, gradient tensors, rotational and horizontal invariants of Asteroid Bennu (101955), Itokawa (25143) and Eros (433) via 2D Non-Uniform FFT
No full textThe internal structure and mass distribution of the terrestrial objects are yet unknown. The 2D gravity model with a constant density of the terrestrial objects can shed light on the surficial or textural heterogeneity due to topographic variations of the terrestrial objects. Three different steroids, which are Bennu (101955), Itokawa (25143) and Eros (433) are modelled in this study. During the modelling phase, a different number of edges, elements, nodes, and faces are used to describe the 3D models of Bennu, Itokawa, and Eros. These 3D models are used in 2D Non-Uniform Fast Fourier Transform (NU-FFT) applications to obtain gravitational attraction with a constant density polyhedron model. Tensor gradients and tensor invariants of the modelled gravity anomaly are calculated. Three major outcomes are interpreted from tensor gradient and tensor invariants. Firstly, textural heterogeneity due to relatively low topography is detected in the central part of Bennu. Secondly, considerably different properties which can be related to surface variations between the two lobes of Itokawa are observed. Lastly, directional surficial heterogeneities were detected in Eros
Fossil fuels, climate change, and the vital role of CO2 plays in thriving people and plants on planet earth
No full textA rigorous examination of empirical data confirms the fact that there is no threat from CO2 to People. Fossil Fuels (i.e., Oil, Natural Gas, and Coal) are the underpinning of modern living in the 21st century and that CO2 is essential for the thriving of both People and Plants. The geologic record shows that the Earth’s climate has always been changing naturally during the past 600 million years in terms CO2 and temperature, without CO2 emissions from Fossil Fuels by humans. A plot of CO2 vs. Temperature for the last 600 million years shows basically no correlation for most of this time (Berner, 2004; Scotese et al., 2021). If the Net-Zero CO2 policy were to be implemented in 2050, large numbers of people would die and the modern human civilization would come to a sudden halt, and humans left alive would have to revert back to the lifestyles of the Neanderthals. A climate-change model for 200 years (1900-2100) is proposed based on four basic parameters, namely, CO2, Temperature, Population, and GDP (gross domestic product) per capita. In this model, calculations based on the Max Planck’s Curve by Van Wijngaarden and Happer (2020), an increase in Temperature by 2100 would be trivial even if CO2 is nearly doubled in value to 800 ppm. The CO2 in the atmosphere helps not only to modulate the Earth’s Temperature suitable for human survival, but also to enhance Global Greening
Paleocene-Eocene foraminifera from the Tuz Gölü Basin (Salt Lake Basin, Central Türkiye) and their paleoenvironmental interpretations
No full textPaleocene-Eocene aged sediments from the east of Tuz Gölü Basin (Central Türkiye) provide significant data for foraminifera contents and their paleoenvironmental clues. They are important in revealing the stratigraphy of the region and the Paleocene-Eocene geological history of Türkiye. The sediments, composed mainly of carbonates, are known as Karapınaryaylası Formation. In this formation, benthic foraminifera representing SBZ2 to SBZ12 biozones corresponding to the Selandian-Late Cuisian time interval were identified in ten measured stratigraphical sections. The zonal interval from the E7 Zone (late Ypresian) to the E10 Zone (Lutetian) is characterized by the marker species of planktonic foraminifera defined in the clayey limestones from the uppermost part. The studied formation is divided into four main facies and eleven sub-microfacies types. The clayey limestone levels of the Karapınaryaylası Formation, which generally starts with a transgressive sequence, contain abundant planktonic foraminifers, while the lithologies of grainstone, packstone and wackestone are rich in benthic foraminifers. Benthic foraminifer assemblages indicate different paleoenvironments from lagoon to back-bank, bank and fore-bank. The obtained foraminiferal data show the Selandian-Lutetian age range and various paleoenvironments from the lagoon to the open sea
Vitrinite reflectances and mineralogy of coal clasts in the Late Carboniferous sequences in the two-deep research wells from the Kozlu coalfield (Zonguldak Basin, NW Türkiye)
No full textFifty-four coal clast samples in the siliciclastic rocks (e.g., sandstone and conglomerate) were collected from cores of two-deep research wells (K20H and K20K) drilled at the Kozlu coalfield in Zonguldak Basin, and for the first time, they were evaluated using mineralogy by XRD and SEMEDX and random vitrinite reflectance (%Rr) measurements in order to find out their origin and timing. Petrographic observations on polish surfaces show that the coal clasts are either entirely xylitic/vitrinitic particles or coals including a broader range of macerals. The detected minerals in the samples are mostly derived from the parental coal seams and, to a lesser extent, precipitated from penetrated pore-water in the cleats/fractures of clasts. The %Rr values of coal clasts in Carboniferous sediments are generally relatively higher than those measured in the coal seams due to weak oxidation during transportation. Furthermore, similar mineralogical and maceral compositions between coal clasts and coal seams imply that these clasts were mainly eroded during the peatification and/or early coalification of parental seams and display similar coalification patterns. The close %Rr value of a coal clast sample in the Early Aptian Zonguldak Formation and Carboniferous coal seams could suggest that this coal clast sample is presumably derived from the coal seams eroded during Early Aptian
A simple and practical tool for indirect determination of the unconfined compressive strength of most common construction materials
No full textDetermination of the unconfined compressive strength (UCS) of construction materials in the laboratory is tedious and time-consuming. There have been many attempts to indirectly predict UCS using simpler tools and techniques. One of them is the nail gun. The scope of this investigation is to design a nailer which can be applied all construction materials whose UCS range from 1-100 MPa. In the research, rocks, bricks, and concretes prepared in different cement/sand ratios with different strength ranges were used as materials. The unconfined compressive strength of the materials used in the experiments was first determined by conventional compression tests. The nail penetration depths were determined by conducting experiments on the same materials using a nailer with two different energy levels. An empirical relationship was developed by using nail penetration depths, driving energies, and nail diameters as the independent variables and the UCS determined by the conventional method as the dependent variable. According to the empirical relationship determined by multiple regression analysis, the UCS of building materials can be estimated with significance level of 99% by the nail penetration method. The research also revealed that the UCS of rocks might have a coefficient of variation as high as 30%