Bulletin of the Mineral Research and Exploration (BMRE)
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1932 research outputs found
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Post-halite gypsum pseudomorphs with evidence of challenging climatic conditions and diagenetic replacement: a study from the southwest of Kağızman Basin (Eastern Anatolia, Türkiye)
No full textThe study area is about the evaporitic-dominated Middle Miocene sequence situated in the southwest of the Kağızman Basin in Eastern Anatolia. The aim of this study is to investigate the formation conditions and diagenetic development of pseudomorph gypsum formed after halite. Pseudomorph gypsum formations are intriguing geological features found in terrestrial deposits. These formations are replaced by primary halite crystals during the very early phases of diagenesis, giving the appearance of halite crystals but being composed of gypsum. The development of these pseudomorphs is indicative of specific paleoenvironmental conditions. The fact that these gypsum pseudomorphs are found in shallow depths of the lake and are well-preserved, smooth-surfaced, and varying in size suggests that they were the result of intense evaporation and rapid fluctuations in the water and pH level. This evaporation likely led to a decrease in the lake level and changes in the concentration of saltwater over time. The correlation coefficient relationships and element concentration values of these gypsums show that these elements are both continental in origin and subject to microbial influence. These pseudomorph gypsum and the clastic materials (transported by fluvial activity) that were interbedded gave important insights into the hot, long-drought, and lowhumidity climate of the era and adapted to the Middle Miocene global warming condition
Assessing groundwater quality in semi-arid conditions: a geographic information systems-integrated approach using water quality index
No full textMeeting freshwater demands in water-scarce regions is imperative, given challenges like hydric stress, urbanization, aridity, and population growth. This study focuses on the Tebessa aquifer system, a critical water source facing escalating demands. A primary objective is to identify actionable management strategies to improve groundwater quality dynamics in semi-arid regions. The methodology involves a comprehensive assessment of groundwater health using the Water Quality Index (WQI) approach. This method integrates diverse parameters influenced by intensive agricultural and industrial activities. Additionally, spatial relationship analysis, facilitated by Geographic Information System (GIS) technology, is employed to gain insights into complex hydrogeological processes. The multi-parameter strategy implemented results in water quality maps that highlight various ions, revealing spatial disparities and assigning quality priority classes from ‘Good’ to ‘Poor’ across the groundwater. The research, conducted in the semi-arid Tebessa-Morsott Plain, encompasses field and laboratory investigations to delineate hydrochemical traits, including alkalinity, salinity, and heightened ion concentrations. The results of the study contribute to scientific understanding by uncovering interrelationships and spatial intricacies, offering valuable insights for water resource governance. The effectiveness of the methodology, incorporating WQI and GIS, is demonstrated in the comprehensive evaluation of groundwater quality. Ultimately, this research provides a foundation for informed decision-making and sustainable management of groundwater resources in semi-arid regions
Economic heavy minerals in the stream sediments of wadi Shaàb, southern coast of the Red Sea, Egypt; characterization and upgrading for investigation of their potential recovery
No full textThe southern coast of the Red Sea is one of the most promising areas for the occurrence of economic minerals. Therefore, studying the characterization and evaluation of these minerals in the Wadi Shaàb Quaternary sediments and investigating their ability to concentrate and physically separate using economical and ecofriendly techniques is the main goal of this work. The results showed that the representative sample contains an average of 0.06% ilmenite, 0.08% zircon, 0.07% rutile, 0.07% leucoxene, 0.008% cassiterite, 0.004% xenotime, 0.0004% monazite, 0.022% almandine garnet, and 0.46% magnetite. The recovery of economic heavy minerals was applied using a combination of wet-gravity technique via shaking table and magnetic separation using high intensity magnetic separator. The results demonstrated the success of gravity separation in raising the grade from 7.63% to 45.03% in a yield of 13.74% out of the original sample, and also valuable metallurgical recoveries that higher than 89% for tabling multi-stages (rougher and scavenging) was obtained. Concentrated mineral fractions of magnetite, ilmenite, almandine, heavy silicates, and the nonmagnetic fraction bearing zircon and rutile were obtained using a high intensity magnetic separator at different ampere range
Origin of the mineralizing fluids involved in the formation of the scheelite skarn in the Beleleita area (Edough NE, Algeria): Fluid inclusion and stable S, O and C isotope study
No full textThis study investigates the first stable S-, O- and C-isotopes data on the Beleleita scheelite skarn deposit to assess the origin of the mineralising fluids involved in the formation of the skarn and related W-As-Bi-(Au) mineralisation. Two skarn bodies are embedded within the Neoproterozoic gneisses, south of the Edough metamorphic complex, NE Algeria. They show subparallel, discontinuous slabs (F1 and F2) approximately 700 m long and 10 m wide, striking NE–SW. The slabs were cross-cut by bore-hole drilling at a depth of 130 m during ORGM (Office de Recherche Géologique et Minière) mining exploration in the 1980s. Textural observations reveal two main cycles. Cycle I displays early classical zoned skarn assemblage, including clinopyroxene, garnet, plagioclase, pyrite, pyrrhotite, and chalcopyrite. Cycle II shows late lithiniferous and fluorinated skarn assemblage that corresponds to greisenised secant skarns, with fluorite, scheelite, lollingite, allanite, zinnwaldite series, sphene, wolframite, arsenopyrite, native bismuth, and quartz. Stable O-isotope analyses were carried out on both whole-rock samples and clinopyroxene, quartz, and garnet mineral separates, whereas C- and O-isotope analyses were conducted on gangue calcite. S-isotopes were carried out on sulphides (pyrite, chalcopyrite, lollingite and pyrrhotite). All the results display relatively narrow ranges (δ18OSMOW varying from +8.4 to +9.9‰; δ13CPDB ranging between -6.9 to -4.2‰ and δ34SCDT between -0.3 to +5.3‰), indicating a homogeneous source of fluids with significant magmatic signatures that contribute to skarn formation and ore deposition. Accordingly, the involved mineralising fluids most likely originated from the I-type magmatic event that prevailed during Burdigalian times in the Edough massif, similar to many other ore deposits in the area. Moreover, previous fluid inclusion studies carried out on fluorite, scheelite, and quartz of Cycle II show that the ores were deposited from hot (Th = 500°-520°C), highly saline magmatic fluids under low pressure (0.5–0.6 kb), and this complies well with the present stable isotope data
Time-lapse ground penetrating radar (GPR) imaging of used engine oil contamination
No full textTime-Lapse Ground Penetrating Radar (GPR) was employed to study used engine oil (UEO) contamination of sandy environment in laboratory setting. GPR is a near-surface geophysical method that uses electromagnetic field to provide image of the dielectric properties of earth materials to detect structures and changes in material properties within the subsurface. This research aimed to detect, monitor and map the migration of UEO contaminant in sand. The results of this study revealed that the migration of the UEO contamination in homogeneously laid sand is non-uniform. UEO plumes were identified as high amplitude signals with enhanced reflectivity. There was a progressive decrease in GPR signal amplitudes (reflection reduction) within the contaminated area of the tank with time. This decrease of GPR signal amplitudes was interpreted as caused by the evaporation of some portion of the UEO in the vadose zone as a result of temperature increase in time and also due to the occurrence of UEO biodegradation. The time-lapse GPR proved to be an effective technique for detecting, monitoring, and mapping UEO migration within sand tank in laboratory setting
Anthropogenic problems threatening major cities: Largest surface deformations observed in Hatay, Türkiye based on SBAS-InSAR
No full textThe surface deformation caused by tectonic activities and anthropogenic factors poses a great threat to cities worldwide. The investigation and monitoring of these deformations are crucial in order to create risk analysis for the future. The problem in this case is to investigate the surface deformations and their negative effects caused by groundwater use and to identify possible landslide areas. In this study, the surface deformations in Hatay province were analyzed using SBAS-InSAR. The results from these analyses were evaluated by field observations. Sentinel-1 descending (183 datasets) and ascending (147 datasets) track geometries were selected to determine the surface deformation and its temporal evolution. Both east-west and vertical surface deformations were calculated, and the surface deformation profiles, surface 3D models and time series were created. These time series were associated with monthly precipitation data. The deformation area was interpreted with regard to available well-log data and geological setting of the study area. As a result of the study, a surface deformation resembling a bowl like structure was observed in the industrial zone located in the city center of Hatay-Güzelburç. The deformation rates are approximately 22.3 cm/year in the form of subsidence, 3.6 cm/year in the form of eastern movement and 10.1 cm/year in the form of western movement. The deformation of this bowllike structure decelerated in the winter and accelerated in the summer due to excessive water use. The average monthly precipitation dataset supports these results. The stratigraphic data from water wells and the presence of limestone outside the eastern boundary of the deformation area show a thick clay layer in the eastern block of the bowl-shaped deformation structure. The difference between these two units, which causes a sharp anomaly at the eastern border of the deformation area, is interpreted as a probable normal fault. The second study area where surface deformations are observed is the landslide zone. The deformation was found to be 7.5 cm/year in a westward direction and 1.5 cm/year as subsidence
Edge enhancement of potential field data using the enhanced gradient (EG) filter
No full textPotential field data play a critical role in interpreting various geologic structural features through edge detection filters that aid in mapping subsurface structural features. For this purpose, various filters have been introduced in recent years to determine lateral boundaries. However, each of these filters has its limitations and advantages. This study presents a new edge enhancement filter named Enhanced Gradient (EG) based on the Richards function and applies it to potential field data for structural mapping. The EG is tested on two dimensional (2D) and three dimensional (3D) synthetic magnetic models with sources buried at different depths and variable properties. The results from the EG filter provide more accurate and higher resolution horizontal boundaries and can avoid creating the false edges in the output results. In addition, the proposed filter was examined using aeromagnetic data from the Indiana region in the USA. The primary and secondary faults and geological formations are recognizable in the EG image. The results of the EG map will allow us to improve the qualitative interpretation of potential field anomalies in studying the structural and tectonic geology of the Indiana region in the USA
Structural relationship between subsurface oil fields in the North Dezful Embayment: Qaleh Nar, Lower and Upper Balarud Anticlines (Central Zagros, Iran)
No full textHow subsurface anticlines (oil fields) link structurally with faults is of great relevance in the exploration and development of oil fields. In this context, we investigate the geometric relation between lower Balarud (LBR), upper Balarud (UBR) and Qaleh Nar (QN) subsurface anticlines that are the main oil fields in the Northern Dezful Embayment, central Zagros. The Asmari (As) and the Bangestan (Bng) reservoirs are studied geophysically using seismic profiles, well data and underground contour maps (UGC). Interpretation of 3500 m deep seismic profiles indicates the geometry of the studied subsurface anticlines differs vertically and horizontally to a significant proportion. The interpreted structures much resemble As and Bng horizons in each anticline. The UBR got overturned on the LBR due to thrusting possibly in the Late Miocene. The LBR, like a rabbit-ear structure, is situated at the northern edge of the QN. The lower and upper Chenareh and LBR and UBR resemble structurally and are separated mutually by a steep (strike-slip) fault. The fault separates the LBR and UBR from the QN. Interaction of different factors change in overburden pressure, rate of deformation and uplift in the different parts of the subsurface anticlines moved and accumulated Gachsaran Formation towards both limbs of the anticlines
Archaeoseismology: Earthquake traces studies in ancient settlements; a chronological evaluation from the World focusing on Türkiye
No full textArchaeoseismology is a field of science that investigates the remains of ancient human structures of destructive earthquakes that occurred in their ancient history and in this respect makes inferences on the possible effects of earthquakes whose origins will be may occurred in the future. Although many authors wrote the effects of ancient earthquakes in various periods, the first modern archaeoseismology studies in the world gain momentum starting from the end of the 19th century at the same time with Türkiye. In this understanding, the geography of Anatolia (Asia Minor), which has hosted a wide variety of cultural layers since its Mesolithic end, is an open-air research laboratory for modern archaeoseismological studies. This study is a reference work that summarizes the historical past of the discipline of archaeoseismology chronologically in the perspective of studies on Earth and Anatolia, presents suggestions about the future of archaeoseismology and is a literature summary for the new generation of archaeoseismologists
Investigation of gas and gas hydrate accumulations along the continental margin of the Danube Delta (Romania and Bulgaria offshore) using seismic reflection data
No full textIn 2012, a comprehensive study of the Danube River’s submarine channels continental slope was conducted, employing multi-beam bathymetry and over 2300 km of high-resolution two-dimensional seismic reflection data. The investigation aimed to delve into the area\u27s morphology, potential for gas hydrate presence, and the correlation between stratigraphic units and gas hydrates. Three distinct zones, revealed Bottom Simulating Reflectors (BSRs) indicating the base of gas hydrate accumulations in the seismic data. These BSR areas exhibited Type-1 reflections, characterized by continuous cuts across layers. Notably, five discrete levels of BSRs were detected, suggesting a consistent gas composition across them. The multiple BSR formations are attributed to higher sedimentation rates relative to gas hydrate dissolution rates. Mass transport deposits (MTDs) within the gas hydrate stability zone (6 in total) were identified; their highly consolidated nature could account for the absence of gas hydrates within them. Additionally, one MTD displayed elevated heat flow measurements, indicating a higher geothermal gradient, likely due to its relatively high thermal conductivity. This disparity in thermal properties explains the deeper-than-expected BSR in this specific region, as it forms at a lower temperature equilibrium level due to efficient heat conduction