Geological Journal最新文献

The increasing demand for heavy metals has led to extensive excavation of their ore deposits. The leaching of heavy metals from active and abandoned mines can contaminate the water resources available nearby. The present study evaluates the extent and spatio-temporal variability of heavy metal concentrations in groundwater and surface water resources around the chromite mining regions of the Sukinda Valley, Odisha, India. Twelve surface water samples were collected from the major stream flowing through the region, and 30 tube wells located close to the mining regions were also sampled for groundwater. The samples from the same sites were collected twice, once during pre-monsoon and again in post-monsoon seasons. All samples were analysed for major ion and heavy metal concentrations. Major ion chemistry indicates that the water is of Ca-Mg-HCO₃ type during both seasons. There are no large-scale seasonal variations in the groundwater chemistry; however, a significant seasonal change in the hydrochemistry of surface water has been observed. Heavy metals such as Cr, Fe, Mn, Ni and Zn were detected (> 5 μg/L) in more than 30% of samples, out of which Fe and Cr were identified as the major contaminants. Iron concentrations above the WHO prescribed limit in drinking water have been found in more than 70% of groundwater samples, while higher Cr concentrations were observed in 20%–23% of groundwater samples. Heavy metal pollution indices suggested around 50%–60% of groundwater samples were contaminated with heavy metals, while the surface waters were close to critical condition. Groundwater contaminations with these heavy metals are prominent mainly in the densely populated central regions of the study area. Bivariate cross-plots of major ions indicated the hydrochemistry of the area to be controlled by sediment–water interactions, especially silicate weathering and carbonate dissolution. Multivariate analyses combined the measured water quality parameters based on their analogous behaviour and confirmed the above processes controlling the water chemistry. From a combined statistical analysis and pollution indices, it has been confirmed that geogenic and mining-related activities are responsible for heavy metal contaminations both in groundwater and surface water resources of the region. Weathering of the local lithology, leaching and discharges from the mines were identified as the dominant contributors of heavy metals to the water resources.

The Abiod carbonate reservoir of the Campanian-Early Maastrichtian age represents a major oil reservoir In the Pelagian block of eastern Tunisia, forming complex fractured networks that are poorly understood. Given the total absence of geological outcrops of Campanian-Maastrichtian age in the study area, 2D seismic reflection, geological modelling and well log datasets were integrated to characterise the subsurface geodynamic structures, investigate the petrophysical characteristics, the relationship between fault systems and fracturing and define their implications for petroleum exploration. Analysis of seismic profiles, lithostratigraphic logs, borehole data and geological modelling has shown the prevalence of three major fault networks: northwest–southeast (NW–SE), E–W and northeast-southwest (NE–SW). These faults have controlled the thickness of the limestones of the Abiod reservoir, favouring highly subsiding NW–SE trending zones where the thickness has exceeded 500 m. Based on responses of the Gamma Ray (GR) and Sonic curves, this formation is made up of four different lithological units (U1–U4). The wireline log analyses concluded that the gross thickness of the Abiod reservoir includes good reservoir property intervals with average effective porosity ranging from 8.6% to 20.6% and average shale volume ranging from 2% to 17%. Furthermore, analysis of the fracturing affecting the Abiod reservoir, based on oil well FMS image logs, has shown the presence of open and partially open fractures that are key to hydrocarbon accumulations. The rose diagrams of fracture directions at the wells and the rose diagram of major fault directions of the map are in perfect agreement with the clear predominance of the NW–SE directions. Beyond the main uplift faults, the structural features that impact the studied area's stratigraphy are divided into three main categories. This study showed that the brittle tectonics play a role in the enhancement of the petrophysical characteristics of the studied limestone reservoir and controlled the charge access of the hydrocarbons into the reservoir. The majority of the fractures affecting the Abiod reservoir are parallel to the large fault and have the same direction of movement, while the others are distributed in a conjugate family close to perpendicular to the large fault and with complementary directions of movement. The combination of geological factors and logging parameters indicates that the tectonic legacy and structural inversions play an important role in the structuring of the cover and the evolution of the petroleum system, which have made this chalk one of the most important oil reservoirs in eastern Tunisia. Finally, the developed 3D structural model suggests favourable locations for high-potential areas in the studied region and provides insights for the reservoir development.

Landslide is one of the most sought-after research areas in the current multidisciplinary geoscience studies. In this study, a landslide susceptibility map was developed using a Multi-Criteria Decision Analysis (MCDM) framework with the Analytical Hierarchy Process (AHP) in the Dima Hasao district of Assam, India. The region is located in the western extent of the Assam–Arakan fold belt. It is characterised by extensively folded and faulted mountainous terrain. The region is highly susceptible to landslide hazard due to several factors including climatic factors, weak lithologic conditions, anthropogenic activity and so forth. This study utilised a GIS-based approach of mapping landslide susceptibility zones; geoprocessing of 12 landslide causative factors was considered, namely slope, rainfall, elevation, geology, distance from fault, drainage density, distance from drainage, curvature (Cu), distance from road, Land Use/Land Cover, Topographic Wetness Index and aspect were utilised by the AHP algorithm. Weightage criteria are assigned to all the 12 factors on a scale of 1–5 based on the significance of landslide occurrence. The AHP algorithm classified four landslide susceptible zones of different hazard, that is, low, moderate, high and very high susceptible zones. The obtained landslide susceptibility model was validated using the area under the curve (AUC) of the receiver operating characteristics (ROC) with an accuracy of 0.864, which confirmed its reliability.

The present-day structure of the southern Izu-Bonin arc-trench system appears to have been influenced by the partial subduction of the Ogasawara Plateau beneath the Philippine Sea Plate, which has significant tectonic consequences. Unfortunately, there is insufficient information regarding the effects of the Ogasawara Plateau collision on the geophysical and seismic characteristics of the region. Therefore, we employ the geophysical and seismic analysis on the gravity and bathymetry datasets, seismic events and earthquake moment tensors to examine the geophysical and seismic patterns of the southern Izu-Bonin subduction zone, thereby uncovering the effects of the Ogasawara Plateau subduction. The results show that the Ogasawara Plateau forms uplift/upthrusts and large fractures/faults in the outer rise region at its subduction area. Several uplifted tectonic features are observed along the southern Izu-Bonin Trench axis at the area of the Ogasawara Plateau collision, where also the bathymetry is approximately 3 km elevated compared to other sections of the trench. Several conspicuous seamounts, uplifts, depressions and ridges are visible in the outer forearc region affected by the collision of the Ogasawara Plateau. Moreover, abnormal low Bouguer gravity anomalies are detected in both the outer and inner forearc regions around the area associated with the Ogasawara Plateau subduction. An area with a scarcity of earthquakes is observed to the west of the Ogasawara Plateau, suggesting a density contrast within the subducting Pacific Plate beneath this region. A seismic gap (moderate to great magnitude [Mw > 4]) is observed in the subducting Pacific Plate at depths ranging from 200 to 500 km around the Ogasawara Plateau subduction area. This study shows that the Ogasawara Plateau subduction influences geophysical properties, seismic activity and faulting in the southern Izu-Bonin subduction system. It also improves understanding of subduction dynamics and the seismic effects associated with the subduction of large bathymetric highs.

China's rapid industrialization and economic development have significantly contributed to rising CO₂ emissions, posing a direct challenge to sustainable development objectives. This study investigates the relationship between aquaculture production, renewable energy consumption, energy intensity, and CO₂ emissions in China, with a particular focus on the role of aquaculture production and renewable energy consumption in shaping emission patterns. Employing the Method of Moments Quantile Regression (MMQREG) and Bootstrap Quantile Regression (BSQREG) approaches, the analysis explores the nonlinear dynamics across various quantiles of CO₂ emissions. The findings reveal that renewable energy consumption and energy intensity exert varying effects on CO₂ emissions across different emission levels, with the most pronounced impact observed in the lower quantiles. The study underscores the necessity of considering regional and sectoral disparities when formulating emission mitigation policies. It highlights the importance of China's ongoing transition toward renewable energy, enhanced efficiency, and region-specific policy interventions, particularly in high-emission areas. These insights contribute to the discourse on sustainable development in emerging economies, offering practical implications for policymakers and avenues for future research, particularly in regional variations and economic determinants of CO₂ emissions.

The rapid use of electrical and electronic devices due to their wide applications in various fields produces a large amount of e-waste (electronic waste) in the modern world. To overcome this problem, there is a need to recycle the used product into useful products from e-waste. Therefore, this approach is essential for the development of advanced technologies for the recovery and separation of REEs (rare earth elements) from e-waste. Here, REEs are sometimes referred to as the “vitamins” of the modern industry. E-waste can contribute significantly to REE pollution since it is frequently handled hazardously and contains high amounts of REEs. Apart from the harmful effects on the environment, these wastes also destroy precious materials such as gold, silver, copper, platinum, palladium, and rare earth elements. Every year, 50 million tons of e-waste is generated worldwide. A large amount of e-waste goes to waste as only 20% of it is handled properly worldwide. The various approaches, including bioleaching, biosorption, siderophores, pyrometallurgical, and hydrometallurgical processes, have been reported in numerous studies on the recovery and separation of rare earth elements (REEs) from electronic waste. This review paper provides an overview of the introduction, characteristics, sources, and applications of clean and green energy technologies. The current pathways for REEs production and recovery point out significant deficiencies in methods currently in use and emphasise areas where multidisciplinary research may lead to more practical solutions. A summary also provides the impact of e-waste on health and the environment. The challenges, research gap, and future directions and suggestions are reported at the end of this review paper.

Shale oil and gas, as an essential type of unconventional oil and gas resources, and compressibility is one of the most critical aspects of shale oil and gas exploration and development. Elastic parameters have a significant impact on the compressibility of shale. Montmorillonite is one of the typical clay minerals in shale, and its microstructure has unique characteristics. When encountering water underground, it is effortless to expand. Therefore, the study of the mechanical properties of montmorillonite is crucial. This study is based on molecular dynamics simulation to establish Na-montmorillonite with different hydration degrees, change its temperature and pressure, conduct comprehensive research and comparison by combining the elasticity parameter of montmorillonite with different hydration degrees, and explain the micro mechanism of its impact. Simulation results display that the mechanical properties of hydrated montmorillonite are negatively correlated with temperature. There is a positive correlation with pressure. As the degree of hydration increases, the mechanical properties of montmorillonite decrease. The mechanical properties of montmorillonite are anisotropic. The factors that play a leading role in the stage of temperature, pressure and hydration degree under micro and macro conditions are studied. This research achievement has guiding significance for the comprehensive understanding of montmorillonite and the elastic parameters of shale at the micro level.

This review presents new insights on the origin of primary arc magma and its geochemical signatures in the Barren Island and Narcondam using Arc Basalt Simulator 5 (ABS5). Barren Island rocks are basalt to basaltic andesite showing tholeiitic composition, while Narcondam is mostly andesite showing calc-alkaline composition. ABS5 indicates that slab dehydration and P–T conditions were similar, and slab liquid uptake was highest from the altered oceanic crust, followed by sediment and mantle wedge coupled to slab top. Unlike trace elements, the ⁸⁷Sr/⁸⁶Sr–¹⁴³Nd/¹⁴⁴Nd ratios of the slab liquid show a depleted signature in Barren Island compared with Narcondam, due to R% (reactivity between solid and liquid in the slab). The initial mantle composition in the Barren Island and Narcondam indicates prior melt extraction of < 0.5%–1.5%. Barren Island shows lower β% (fraction of slab liquid in the partial melt) than Narcondam. The H₂O content in slab liquid was slightly higher in Barren Island (7.3–8.6 wt%) than Narcondam (5.5–6.8 wt%). Accordingly, the degree of partial melting (F = 10.9%–20.20% in Barren Island, F = 5.3%–10.5% in Narcondam) and total melt productivity (%) were higher in Barren Island compared with Narcondam. ABS5 indicates that the slab liquid contributed LILE, LREE, Th, U and ⁸⁷Sr/⁸⁶Sr-¹⁴³Nd/¹⁴⁴Nd, while the mantle melts contributed HFSE, MREE, HREE, Y¹⁴³Nd/¹⁴⁴Nd in Barren Island and Narcondam. ABS5 indicates that the total melt production (%), H₂O content in slab liquid and mantle wedge were higher in post-caldera than in pre-caldera rocks.

As hydrocarbon exploration progresses in the Santanghu Basin, tight oil reservoirs in Carboniferous volcanic rocks have become a focal point for exploration and development efforts. This study aims to account for significant industrial oil flow from the tight tuff layers of the Kalagang Formation in well blocks Ma 71 to 33 in the Malang Sag within the basin. Through experiments including organic carbon analysis, rock pyrolysis, and nuclear magnetic resonance (NMR), this study systematically investigated the principal characteristics and determinants of the tight oil reservoirs, culminating in the development of hydrocarbon modes, thus providing a reference for tight oil exploration and production in the study area. The results indicate that the Kalagang Formation is composed predominantly of tuff, especially vitric tuff. The storage spaces of this formation include dissolution pores, tectonic fractures, and dissolution fractures, with devitrification pores less common. Compaction plays a crucial role in rendering the tuff reservoirs tight. Nevertheless, differentiated diagenetic alterations have improved the microscopic storage spaces and their interconnectivity. Well blocks Ma 3301 and Ma 33, having undergone significant weathering (leaching), exhibit superior reservoir physical properties and connectivity compared to well blocks Ma 71 and Ma 73. In contrast, well blocks Ma 71 and Ma 73 experienced more significant alterations due to organic acid dissolution and devitrification under the influence of source rock types and hydrocarbon generation. The comprehensive analysis indicates that tight oil reservoirs in the Malang Sag were formed due to the close superimposition of source rocks and reservoirs, along with the effective connection of source rock-rooted faults. This results in the formation of two sets of proximal tight tuff reservoirs with the ‘lower-source rock and upper-reservoir’ and ‘self-sourced reservoir’ modes.