In order to appreciate the mining waste potential of gold mining exploitation in the locality of Fel and surrounding mining sites, using enrichment factor and mineralization index, were performed geochemical investigations on mining waste from the Neoproterozoic metavolcano-sedimentary formations of the Lom series. The study focuses on geochemical analyses and concerns the assessment of 12 Metallic Trace Elements (MTE) from 10 mining sites. Geochemical analyses show that fine fraction (< 80 μm) always has the best response for all elements. Some MTE have quite remarkable contents in concentrated wastes. This is the case for Au (˃100ppm), Ag (85ppm), Pt (5.8ppm), Th (767ppm), U (29.9ppm), Y (100.6ppm), As (1445.7ppm), Sb (8.4ppm), Se (1.2ppm) and Pb (65.5ppm). On the other hand, some MTE are high in both washed and concentrated wastes, like Au, Se, (As) and (Sb). Light Rare Earth Elements (La, Ce, Pr, Sm, Nd) are characterized by high concentrations, ranging from severe to extremely severe enrichments in concentrated wastes. At the end of this study, it appears that the paragenesis of gold mineralization, induce severe to extremely severe enrichments in Au-Se-Ag-Pt-Th-(As)-(Sb)-(U)-(Y)-(Pb) and Light Rare Earth Elements in the mining wastes of Fel and its surroundings, thus constituting a set of geo-resources that can still be recovered from such wastes.
Currently, research on persistent organic pollutants in permafrost soils has primarily focused on distribution surveys, with limited studies investigating migration mechanisms. This paper examines the vertical migration processes and driving mechanisms of polycyclic aromatic hydrocarbons (PAHs) in permafrost soils. Given the diverse sources of pollutants under natural conditions and the complex mixture of contaminants typically found in soils, this study selected 16 priority-controlled PAHs as research targets. Using loess soil from Lanzhou—a seasonally frozen region—as the experimental substrate, we conducted indoor soil column leaching experiments under freeze-thaw cycling conditions. This approach simulates the vertical migration of PAHs in permafrost soils, to quantitatively describe PAHs' vertical migration and distribution within soil profiles, along with permafrost layer barrier mechanisms. Simulated soil column experiments combining freeze-thaw cycles and leaching were designed to analyze the driving mechanisms of PAH vertical migration influenced by these processes. The results indicate that the driving mechanism of freeze-thaw cycles primarily involves water migration toward the freeze front due to soil surface freezing, leading to upward migration of pollutants. The driving mechanism of leaching primarily involves vertical migration of dissolved-phase PAH pollutants in soil through leachate. The primary driving force is leaching, while freeze-thaw cycles drive PAHs to migrate upward over greater distances.
The Niergui Massif, located at the southern margin of the Sahara Metacraton, represents a poorly documented portion of the Pan-African basement in Chad. This study integrates petrographic and geochemical analyses of syenogranites and gabbronorites to better constrain their nature, origin, and the magmatic processes involved in basement formation. The syenogranites are strongly potassic calc-alkaline, weakly peraluminous, and ferroan, whereas the gabbronorites are metaluminous and moderately differentiated. Major, trace, and rare-earth element geochemistry indicates a progressive magmatic evolution: gabbronorites reflect a primitive mantle source, while syenogranites show enrichment in incompatible elements and differentiation toward crustal magmas. Sr/Y and Rb/Sr ratios, as well as Eu anomalies, suggest that syenogranites formed from a mixture of enriched mantle and crustal sources, whereas gabbronorites are weakly differentiated and mantle-derived. Nb/Zr vs. Zr diagrams and zircon saturation temperatures (700–850°C) indicate that magma crystallization involved both fractional crystallization and partial melting. Tectonic discrimination diagrams (Ta vs. Yb, Rb vs. Yb+Ta) confirm a subduction setting followed by a syn- to post-collisional phase, consistent with the Pan-African dynamics between the Congo Craton and the Adamawa-Yadé block. These results indicate that the Niergui Massif exemplifies a bimodal magmatic system, characterized by mantle–crust interaction, partial melting, and fractional crystallization. The complexity of geochemical signatures reflects local variations and multiple stages of magmatic evolution from mantle to differentiated crustal magmas. This study provides a solid framework for understanding Pan-African geodynamics in the Guéra region and contributes to the characterization of the Neoproterozoic basement of the Sahara Metacraton.
The Hybrid Empirical Method (HEM) is widely used to predict ground motions in regions with sparse strong-motion data by transferring empirically derived ground-motion prediction equations (GMPEs) from data-rich host regions. A fundamental requirement for the reliability of this approach is that the stochastic point-source model adopted for the host region be consistent with the empirical GMPEs developed from the same dataset. Despite its importance, this consistency is often assumed or verified only over limited magnitude-distance conditions. This study presents a systematic evaluation of the observation-calibrated stochastic equivalent point-source model of Yenier and Atkinson (2015, YA15) for California. Both the single corner-frequency (SCF) and double corner-frequency (DCF) formulations are assessed over moment magnitudes Mw 3.0-7.5, rupture distances Rrup of 1-300 km, and frequencies from 0.1 to 10 Hz. Model predictions of pseudo-spectral acceleration are compared with the median predictions of four widely used four NGA-West2 GMPEs, and consistency is quantified using normalized residuals that account for inter-model variability. Results show that the YA15 model generally reproduces the empirical predictions well for moderate magnitudes (Mw 4.5-7.0) over most distances and frequencies. However, systematic discrepancies are identified for small-magnitude events at low frequencies in the near and intermediate distance ranges, at high frequencies in the near field, and for large-magnitude events in the near-fault region. Furthermore, the more complex DCF formulation does not demonstrate systematic improvement over the SCF model at higher magnitudes and exhibits increased variability and larger residual amplitudes in certain magnitude–distance–frequency regimes. These findings delineate the effective applicability domain of observation-calibrated equivalent point-source models in HEM applications and clarify the limitations of the point-source approximation when extrapolated beyond its primary calibration range. The results provide practical guidance for selecting host-region stochastic models in hybrid empirical frameworks and indicate conditions under which more physically detailed finite-fault simulations may be required.
Flooding is a prevalent disaster in both developed and developing nations, exerting a lasting influence on several regions in Lagos State. In this study, the geographical information system (GIS) technique and the analytical hierarchy process (AHP) of the multi-criteria evaluation (MCE) technique were used to create a floodplain map of Lagos State. Rainfall, land use land cover (LULC), slope, digital elevation model, flow direction, drainage density, normalized difference water index (Ndwi), and soil texture map were the eight parameters identified. The data about the factors were obtained from an online source and processed using the spatial analytic tools in ArcGIS 10.6.1. To calculate the relevant ranking weight, the elements were compared pairwise. The output consistency ratio (CR) was 2.7%, which is below the permitted limit of 10%. The weight percentage obtained was then utilized in the weighted overlay operation to identify the flood risk zone. Based on an analysis of the produced land use and land cover in 2020, 2022, and 2024, changes in water bodies were found to be proportional to changes in built-up areas, with a kappa coefficient of the dataset being 82.8%. From the results, up to 25% of Lagos State is covered by water bodies, 58% of the state's total land is in the high flood zone, and less than 1% is in the very high and low flood areas. Overlaying locations subsequently validated the result declared flood-threatened by the National Emergency Management Agency (NEMA), giving an agreement ratio of approximately 85% and found to fall within the high flood zones.
Utilizing 2D and 3D seismic data, a large-scale detachment thrust structure within the Lower Paleozoic Ordovician Majiagou Formation (O1m) has been identified west of Lishi in the eastern Ordos Basin. This study investigates the structural characteristics, spatial distribution, evolutionary stages, and exploration potential of this structure. The results indicate: (1) The Lower Paleozoic Lishi West Detachment Thrust Belt (DTB) in the eastern Ordos Basin margin is 5–10km wide, extends nearly north-south parallel to the Lishi Fault Zone, and has considerable strike length. (2) The main faults of the Lishi West DTB initiated in the Precambrian and subsequently underwent four major evolutionary stages: stable sedimentation in the Ordovician epicontinental sea; formation of the detachment thrust belt from the Late Ordovician to Late Carboniferous; stable sedimentation from the Late Carboniferous to Middle Jurassic; and compressional uplift from the Middle Jurassic to Cretaceous. (3) The Lishi West DTB originated during the Caledonian period as a deep-seated structural weak zone. During the Yanshanian period, the eastern basin margin experienced westward compression, leading to regional tilting and uplift. Stress release along this pre-existing weak zone caused significant variations in formation dip angles and fault characteristics across the belt. This DTB is interpreted as the boundary separating the Jinxi Warp-Fold Belt and the Yishan Slope. (4) The detachment thrust belt in the eastern margin plays a critical role in hydrocarbon accumulation and subsequent migration/readjustment. The area west of the belt is favorable for exploring various coal-measure hydrocarbon resources, including deep coalbed methane (CBM) and in-source to near-source tight gas. A series of positive structural traps with large aerial extent have developed within the O1m Formation along the Lishi West DTB, demonstrating high exploration potential.
The Menarandra River, located in the Androy region of southern Madagascar, flows through a semi-arid environment characterized by severe water stress, a long dry season lasting seven to nine months, and a short, highly variable rainy season concentrated between December and March. Rainfall records from the Bekily meteorological station over 2000–2017 highlight pronounced interannual variability, with alternating wet years (e.g., 2001, 2005, 2011, annual totals >1,000 mm) and deficit years with totals below 700 mm (e.g., 2002, 2004, 2016, 2017). To better link raw rainfall data to effective rainfall in terms of hydrological response, the analysis incorporates the Turc formula, widely used in water balance studies to estimate potential evapotranspiration and effective rainfall. This approach allows a more precise characterization of hydrological conditions associated with rainfall variability and their potential role in riverbed drying. Rainfall analysis is complemented by qualitative interpretation of Google Earth satellite images processed in QGIS, together with field observations. Comparison of images from December 2014 and October 2018 reveals marked reduction and fragmentation of water-covered areas, indicating increasing spatial discontinuity of surface flow. While the temporal correspondence between rainfall variability and riverbed drying suggests a strong association, river intermittency likely reflects the combined influence of seasonal and interannual rainfall patterns and local hydrological controls. Overall, results indicate a progressive shift of the Menarandra toward a more intermittent flow regime, improving understanding of river drying dynamics in semi-arid southern Madagascar and informing sustainable water resource management under increasing drought conditions.
The Thitsipin Formation exposed at the Pegin Pagoda Hill, Ywa-ngan Township, southern Shan State, Myanmar, represents an important Middle Permian (Murgabian) carbonate sequence within the Shan Plateau. This study presents detailed lithologic, stratigraphic, and paleontological analyses of the limestone unit, focusing on the taxonomy and biostratigraphic implications of its foraminiferal assemblages. Fieldwork involved measurement of stratigraphic sections, fossil sampling, and petrographic examination of 30 thin sections. The lithology is characterized by alternating dark grey, fossiliferous lime-mudstone and crinoidal grainstone interbedded with purplish calcareous shale, forming a 78-meter-thick sequence. Four foraminiferal genera Lunucammina sp., Nodosaria sp., Pachyphloia sp., and Multidiscus padangensis were identified. Among these, Pachyphloia sp. and Multidiscus padangensis are indicative of the Middle Permian (Murgabian) age. The basal portion of the Thitsipin Formation unconformably overlies the Silurian Linwe Formation and yields abundant bryozoans, crinoids, and gastropods, suggesting a shallow marine depositional environment with moderate energy conditions. The discovery of Multidiscus padangensis allows biostratigraphic correlation with coeval units such as the Htam Sang Limestone in Hopong Township. The results confirm the Middle Permian age of the Thitsipin Limestone and refine the regional stratigraphic framework of the southern Shan State. Furthermore, the study provides essential paleontological evidence for understanding the evolution of Permian carbonate platforms in Myanmar and offers a valuable reference for future regional correlations and educational purposes in stratigraphy and paleontology.
Leachate generated from landfill sites represents a major environmental threat, particularly to surface and groundwater resources. Conventional leachate monitoring using boreholes is a one-dimensional approach and does not adequately define the lateral and vertical extent of leachate plume migration. To address this limitation, an integrated geophysical and physico-chemical investigation was carried out at the Sisdol landfill site to delineate the depth and spatial extent of leachate plume migration. The study employed a two-dimensional electrical resistivity survey using Wenner and Wenner–Schlumberger array configurations, complemented by physico-chemical analysis of leachate and surface water samples. A total of six electrical resistivity survey lines were conducted within the landfill site, and five water samples were collected from upstream, on-site, and downstream locations. The resistivity images clearly distinguish leachate plumes, saturated and unsaturated waste zones, and the landfill base. The leachate exhibits very low resistivity values ranging from 0.47 Ωm to 6 Ωm, consistent with its high electrical conductivity of 35010 μS/cm. Physico-chemical analysis indicates elevated concentrations of heavy metals such as manganese, copper, zinc, nickel, iron, and lead in downstream water samples, while upstream samples remain uncontaminated. Lead concentrations exceeding permissible limits were detected at one downstream site. These findings confirm that the poorly managed Sisdol landfill site poses a serious risk to nearby water resources due to leachate percolation and direct discharge into the Kolpu Khola without proper treatment.
Major and trace element geochemistry of sediments is a very useful tool for understanding the provenance, intensity of weathering, tectonic settings, and depositional environment of the sediments. Sediments collected from different geomorphic domains (onshore and nearshore) of Rasulpur to Subarnarekha River mouths estuarine complex, East coast of India, were analyzed for their geochemical (major, trace contents) and mineralogical characteristics to determine their provenance, compositional maturity, paleo-weathering condition, and depositional environment. From geochemical studies, it is evident that the samples from the nearshore area suffered more weathering than the onshore samples. Geochemistry of the sediments suggests the protolith of the area to be of intermediate to felsic source rocks. A relative increase in the Al2O3/TiO2 ratio in sediments also suggests that they are derived mainly from intermediate to felsic source rocks. A strong positive correlation between Fe2O3, MnO, K2O, MgO, CaO, P2O5, and major oxides with respect to Al2O3 indicates that they are associated with micaceous/clay minerals. The Index of Compositional Variability (ICV) indicating low compositional and mineralogical maturity of the sediments. The Chemical Index of Alteration (CIA) value clearly pointing towards intense to intermediate weathering in the source area sediments. Similarly, Chemical Index of Weathering (CIW) results also supporting the same trend of weathering. The results of Plagioclase Index of Alteration (PIA) suggesting moderate destruction of feldspars during source weathering, transport, sedimentation, and diagenesis. The Ternary plot of A-CN-K and the binary plot of CIA/ICV also suggest that both geomorphological domains are immature in nature and suffered intense to moderate weathering. Trace-element concentrations in sediments result from the competing influence of provenance, weathering, diagenesis, and sediment sorting. The felsic province is also corroborated by elevated values of Ba, K, and Sr. EPMA analysis reveals the presence of heavy minerals comprising Ilmenite, garnet as major constituents followed by sphene and rutile. Other minerals include sphene, epidote, amphibole, pyroxene, biotite, apatite, chlorite, tourmaline, muscovite, and alumino-silicate. The concentration of TiO2 in Ilmenitedepicting a metamorphic signature with an igneous source. Micro-textural studies reveal different types of surface features of the grains, the various micro features have been produced by different transportational processes under different environmental conditions. Based on all geochemical and mineralogical data and different plots, it is evident that the sediments from both geomorphological domains are immature in nature and suffered intense to moderate weathering derived from mixed igneous and metamorphic sources.
To enhance sustainable production systems, drylands must face a myriad of problems. Regardless of local conditions, some local practices could help address these problems. However, their applications are not well understood and the results are not well quantified. Our objective was to assess the response of Faidherbia albida (Delile), A. Chev (F.A.) on a Pellic Vertisol and its combined effect with stone walls on an Eutric Regosol. Composite soil samples (0–5, 5-10, 10-20 cm) were collected from these soils under and outside, respectively Faidherbia albida tree and Faidherbia albida tree associated with stone walls, and analyzed for routine laboratory determinations. Statistical analyses were performed to interpret the dataset and assess relationships between management practices and soil properties. The soil quality index (SQI) and the response ratio (RR) were computed to evaluate differences between soils under and outside canopy. Both soils significantly benefited from inputs from F.A. and particularly when combined with stone walls. For Pellic Vertisols, only the superficial layer (0 -5 cm) significantly benefited from F.A. inputs. Here, SQI 1_1uF.A (under F.A.) ˃ SQI 1_1’oF.A (Outside F.A.) . As compared to soils in open field, F.A. contributed 46.24% of SOM (Soil organic matter), 128.23% of total nitrogen, 270.85% of available phosphorus and 254.2% of potassium and improved soil temperature and humidity. When associated with stone walls, the whole plow layer (0-5, 5-10, 10 - 20 cm) on Eutric Regosol, significantly benefited from inputs from the complex F.A. and stone walls. Indeed, SQI 2_1uF.A ˃˃ SQI 2_1’oF.A, SQI 2_2uF.A. ˃ SQI 2_2’oF.A and SQI 2_3uF.A .˃SQI 2_3’oF.A . As compared to the open area, F.A. combined with stone walls brought 141.5% of SOM, 201.9% of total nitrogen, 89.35% of calcium, 495.2% of potassium, 93.3% of sodium, 499.6% of available phosphorus and 109.8% of soil humidity. Improving soil quality through local practices, suitable to local conditions, is key to enhance Sahelian livelihoods.
Research on characteristics, composition, size, shape (fragment, fiber, granular), distribution, and content of microplastics in coastal sediments was conducted through boreholes and excavations on identified cross-sections. Field surveys were conducted in the rainy and dry seasons, drilling (2m/borehole) and excavations (1.0 x 0.8 x 1.0) to collect samples at low tide. Changes in sediment environment and microplastics in the 2m borehole column, and seasonal changes in sediment structure and microplastics were studied in the excavations. Changes in microplastic content in the sediment sample column (borehole, excavation) and sediment OSL age were also determined. Synthesizing documents on the cross-sections will determine the distribution characteristics of microplastics in coastal alluvial sediments in the study area. Coastal sedimentary environments are determined based on analysis of grain size, sediment structure and diatoms in borehole and excavation samples. In addition, geomorphology and coastal sediments play an important role in determining sedimentary environments such as intertidal, subtidal, beach, sand bar, etc. The presence of microplastics with varying composition and content in borehole sedimentary environments of geological cross-sections is the basis for studying the distribution and source of microplastics. The research results show that the microplastic content is medium to very low, about 0-300 microplastics / 1000 g of dry sediment sample, often found in fine, medium and silty sand in the upper intertidal sediments (0 to -0.6 m) with an age of about 30 years ago (OSL age), and does not appear in the lower part of the drill core (from -0.7 m to -2 m). In addition, microplastics do not appear in clay-silt and clay-silt-sand. Two areas with quite concentrated microplastic content are the intertidal flats of Soai Rap and Dong Tranh rivers in Dong Hai commune and the Long Tau river mouth area in Can Thanh town; the intertidal flats in the middle of Long Hoa commune has a non-concentrated microplastic content.
Low-mature shale (Ro = 0.5% ~ 1.0%) is an important strategic alternative in China’s oil and gas resource replenishment and production enhancement. In situ conversion technology is considered the key to efficient development. As one of the main methods of in situ conversion, in situ combustion heating technology has advantages such as low cost and high thermal efficiency. However, its combustion characteristics and pyrolysis mechanism in low-mature shale are not yet clear. This study focuses on low-mature shale from the Songliao Basin, using thermogravimetric analysis (TG), total organic carbon (TOC) testing, and one-dimensional physical simulation experiments to systematically explore its in situ combustion and pyrolysis behavior. The results show that the pyrolysis process of low-mature shale can be divided into three stages: low-temperature volatilization (<250°C), organic matter pyrolysis (250-550°C), and inorganic mineral decomposition (>550°C). The optimal temperature range for in situ combustion modification is between 450 and 500°C, where the organic matter pyrolysis conversion rate exceeds 80%, and the produced oil exhibits significant lightening characteristics. The research findings provide important theoretical support for the optimization and field application of in situ combustion technology for low-mature shale and are of great significance for promoting the sustainable development of shale oil resources in China.
The article offers an improvement of the method for predicting strong ground motion displacements and accelerations, assuming that an earthquake is an instantaneous mechanical rupture of the Earth’s crust. The method uses derived theoretical formulas to calculate all three parameters of the ground motion: displacements, velocities and accelerations during strong (with magnitude M≥6.0) earthquakes for any heterogeneous (multilayer) ground beddings. The article addresses the case of heterogeneous two-layer beddings. The example provided involves the results obtained for 16 variants of two-layer heterogeneous sites in seismic categories I-IV at the magnitude M=7.0, and distance of 15 km from the expected earthquake’s rupture. A comparison of the results obtained for actual heterogeneous foundation beddings with the equivalent homogeneous beddings showed divergences of increase by 1.3-1.6 times, depending on the number of the five and three natural oscillation modes considered. Significant effects of various modes of foundation bedding natural oscillations on ground surface displacements and accelerations were identified when comparing a heterogeneous beddings to a homogeneous ones. A substantial reduction (by a factor of two or more) in the stiffness of the upper soil layer relative to the lower layer leads to a marked increase in surface ground accelerations. A recommendation is provided that the predicted values of displacements and accelerations for heterogeneous foundation beddings should be calculated with consideration of at least 5 natural oscillation modes of the ground bedding. The paper proposes a new analytical solution to the problem of an earthquake as an instantaneous mechanical rupture of the earth's crust with modified boundary and initial conditions of the problem, and also reveals the influence of the ratio of the rigidities coefficients and the geometric parameters of the layers on the amplitudes of seismograms and accelerograms on the Earth's surface.
The combustion of fuels, and biomass and certain industrial activities release highly toxic air pollutants in the natural environment. Nitrogen dioxide (NO2) is also an important trace gas pollutant affecting the climate. In India air pollution is monitored by various government organizations with innovative technologies developed by private sector. Such monitoring networks and tools provide necessary data to be used to frame policy decisions and communicate air quality status to the public at large. It is necessary to know the exact causes and factors responsible for air pollution in India due to certain activities as mentioned earlier. So that people could choose their mode to avoid or minimize the air pollution by adopting suitable actions by them. In this paper, Scanning Imaging Absorption Spectrometer for Atmospheric CartograpHY (SCIAMACHY) is used to observe tropospheric NO2 during 2003-2011 over India. The highest tropospheric NO2 concentration (153-137 µgm–3) is observed in the summer season of 2010-2011 over Northern Indo Gangetic (IG) plain. The NO2 mixing ratios at 350 hPa during November-May for 2003-2011 over Arabian Sea ranged from 200-230 µgm–3 and 90 µgm–3 over Bay of Bengal. It also observed that the NO2 mixing ratios decreased 80-110 µgm–3 over the Arabian Sea and 80 µgm–3 over the Bay of Bengal due to thunderstorms and long range transport of pollutants during monsoon season. These data may be useful for India’s National Clean Air Programme to be used for control of vehicular emissions and industrial emission.
Scientific and technological resources constitute the indispensable material foundation for a country’s scientific and technological innovation and serve as the fundamental safeguard for achieving progress in this field. China has set up a national platform for sharing scientific and technological resources, with a focus on the collection, preservation, and utilization of such resources. This paper summarizes the achievements of the National Science and Technology Resource Sharing Service Platform—National Mineral Rock and Fossil Specimen Resource Center (NMRFC). These achievements span various aspects, including the construction of a specimen resource sharing platform within China's geoscience field, the collection, organization, preservation, and digitization of specimen resources, the establishment of a standardized system, technological innovations, science and technology-enabled sharing services, talent development, international cooperation, and science popularization. Additionally, this paper analyzes the challenges confronting the repository: the quantity of preserved geological specimen resources in China is notably smaller compared to those in Europe and America, and there are substantial discrepancies in the number of specimens held by domestic preservation institutions. Furthermore, it explores future development strategies, suggesting the promotion of the repository's upgrade and the construction of a full-chain science and technology resource sharing service system. This can be achieved by collecting global resources, establishing a multifunctional repository in the Xiong'an New Area, enhancing management and operational capabilities, integrating artificial intelligence technologies, and advancing an international development strategy. These efforts will collectively provide fundamental support for scientific research and technological innovation.
The remediation of low-permeability clay soils co-contaminated with Polycyclic Aromatic Hydrocarbons (PAHs) and Total Petroleum Hydrocarbons (TPH) remains a significant environmental challenge. Traditional Electrokinetic Remediation (EKR) is fundamentally constrained by the high hydrophobicity of these contaminants and strong matrix adsorption, which severely limit their aqueous solubility and mobility. This study systematically investigated the combined effects of critical operating parameters, chemical amendments, and physical constraints on the efficiency of Surfactant-Enhanced EKR (SE-EKR) for a highly contaminated clay matrix. A suite of batch tests was performed to optimize EKR conditions. Key findings demonstrated that operating parameters exert a crucial influence on both current dynamics and contaminant removal. Acidic conditions (pH 4.5) were optimal, yielding the highest average removal rate of 70.97% for 12 target contaminants, primarily driven by the high mobility of H+ ions which significantly boosted electrical current. This elevated current led to increased Joule heating (accelerating VOC volatilization) and enhanced oxidative capacity (improving PAH degradation). The use of the composite electrolyte EDTA further improved performance, achieving 69.29% removal by increasing overall conductivity and effectively solubilizing and desorbing highly adsorbed SVOCs (e.g., Benzo[a]anthracene removal reached 82.41%). Furthermore, increasing the voltage gradient to 2.0 V/cm maximized removal at 73.42%, confirming the importance of electromigration and electrochemical oxidation for persistent pollutants. The incorporation of Activated Carbon (AC) increased the system current by 14.3% and enhanced PAH removal, functioning as a 3D particulate electrode that established internal electron conduction pathways and localized redox reaction sites within the low-conductivity clay. Comparing chemical enhancers, SDBS demonstrated superior solubilization and removal efficiency over Alpha Olefin Sulfonate (AOS), likely due to favorable π-π stacking interactions with PAHs. Finally, the simulation of non-conductive subsurface infrastructure demonstrated its role as a physical constraint, disrupting electroosmotic flow pathways, reducing current, and successfully preventing the severe local contaminant accumulation observed in the EKR control. This research provides essential insights into developing robust, field-applicable strategies for EKR by emphasizing the combined necessity of optimized chemical control and mitigation of physical constraints.
The historical stage-by-stage settings (both scriptural and stratigraphic) for petroleum reserves have received little attention in the Creationist literature. The challenge is how to correlate the Bible’s stages with the history of petroleum reserves inferred from the geological record. Trends in the geology of oil and gas reserves through time can be recognized. These trends were correlated consistently and successively with time stages evident from Scripture. A historical framework for oil and natural gas reserves is proposed in association with Noah’s Flood and its aftermath. A biblical young earth history stage model is proposed including topographic destruction, marine transgression, receding waters, and widespread drying, followed by seafloor spreading and associated continental mountain-building. These are inferred to respectively correlate with Neoproterozoic, Early Paleozoic, Late Paleozoic, Triassic, and Jurassic to Tertiary strata and their contained petroleum reserves. Seafloor spreading and associated continental mountain-building in a new Flood model are inferred to have occurred shortly after the Flood Year itself, but triggered by receding Flood waters. Matters considered in this paper include erosion and marine platforms, tectonic and basin style changes, different types of organic matter source material for petroleum, pre-Flood and post-Flood coal, marine and non-marine deposition, along with global sea level rise and fall, and drying.
The Kutch Basin, of Gujarat, western India, is host to a diverse species of vertebrates and invertebrate faunas, which are both marine and terrestrial in origin. Kutch due its passive continental setting, has experienced multiple transgressive and regressive events on its carbonate platform, and was favourable for the growth and preservation of various living organisms in the Cenozoic. These organisms are mainly foraminifera, molluscs, bivalves, corals, echinoids, oyesters and vertebrates. Here in this work, we discuss, and compare the paleoecosystems of Paleogene with respect to the Neogene, of the Kutch Basin, and discuss how the ecosystem of Paleogene of the Kutch basin changes towards the Neogene. We have also tried to understand the genesis of the Middle Eocene Archaeocete fossil. In the Eocene, we have found large amounts of LBFs, such as Assilina, N. obtusus, Nummulites; mega-invertebrates; and vertebrate fossils such as (Remingtonocetus harudiensis, a middle Eocene Cetacea). In Oligocene formations, the dominant faunas are, Corals, echinoids such as Clypeasteroids and gastropods such as Physa, and very less diversity of LBFs, such as Operculina, Lepidocyclina and Spiroclypeus. The Miocene period is associated with newer taxa of microfossils such as Miogypsina, Ammonia sp, fossilized tree roots and land vertebrates of Gomphotherium indet and Brachypotherium sp. It is concluded, that the Paleogene was dominated by primitive vertebrates, in an isolated tropical forest ecosystem, and the marine faunas resided in shallow marine shelf or reef ecosystem, within a basic environment. Whereas the Neogene, was attributed by newer faunas, which migrated from North Africa and Afro-Arabia, as well as the Tibetan landmass, and resided in cooler drier, forest ecosystems and marsh environment, and the marine vertebrates resided in shallow creek environments and were resistant to terrigenous influx, and acidic environment. We hypothesized that the species of Paleogene of Kutch, morphologically and functionally habituated with a primitive ecosystem and endemic to the Indian sub-continent, whereas the species of Neogene are newer and complex and ancestors to the present day extant species.
Bouguer gravity anomalies are generally correlated with topography in mountainous regions. However, their applicability in geological interpretations of gravity data is often constrained by inaccuracies in terrain correction density. To address this limitation, this study employed regression analysis to ascertain the most suitable terrain correction density by investigating the interplay between free-air gravity anomalies and elevation. The density values were then iteratively refined based on the dynamic relationship between computed Bouguer gravity anomalies and elevation at each stage of iteration. By continuously adjusting the terrain correction density throughout the topographic correction process, we ultimately determined the optimal density value and its corresponding Bouguer gravity anomaly. This methodology was applied to gravity data gathered from Jiuzong Mountain, where the ideal terrain correction density was attained after five iterative cycles. The resultant Bouguer gravity anomaly was subsequently calculated, and the efficacy of the proposed method was corroborated by the empirical findings derived from Jiuzhong Mountain.
