Geological Studies Research Articles

Bedding surfaces: true substrates and Earth's historical archive – an introduction

Bedding surfaces are innate components of the fabric of sedimentary successions and define the beds that they bound. However, despite their ubiquity across many sedimentary strata and their use and description in a huge variety of geological studies, the importance and diversity of these stratal phenomena can frequently be overlooked and ill-defined. In this introductory text, a brief review of the history of understanding of bedding surfaces is presented: from the seventeenth-century origins of the lithological use of the word ‘bed’ to recent advances such as the isolation and use of true substrates, as bedding surfaces that archive the ancient interface between substrate and air/water. The open questions and contradictions that persist in our understanding of bedding planes, and their utility in interpreting Earth history, are summarized and provide the springboard for introducing the diverse papers in this volume. Together, the papers collected here shed new light on these familiar phenomena from several angles, including sedimentological and stratigraphic discussions of the divergent origins and meanings of different types of siliciclastic and carbonate bedding surfaces, details of practical considerations when using bedding surface signatures in palaeontological and ichnological studies, and a series of case studies illustrating how bedding surfaces (and particularly true substrates) can inform palaeoenvironmental reconstructions.

Probabilistic analysis of seismic hazard: expe-rience and prospects of implementation in Ukraine

Ukraine's desire to integrate into the global political and economic space involves a transition to international standards. The requirements of international regulatory documents for seismicity assessment differ from domestic standards. In addition, the approach of assessing seismic hazard in points and the subsequent transition to soil movement parameters raises many questions from foreign specialists who act as international experts in survey work when designing facilities with foreign investments, such as tailings dumps of mining and processing plants, or facilities with an international audit, such as nuclear power plants. This issue may become even more relevant during the period of post-war reconstruction of Ukraine, when funds from other countries will be attracted for development. Fulfilment of international requirements involves conducting a probabilistic seismic hazard analysis (PSHA) during the design and operation of nuclear power plants, large hydraulic structures, which include hydropower facilities and tailing dams of mining and processing plants. In Ukraine, the greatest experience in performing PSHA is available for nuclear power plants. With the participation of the authors, the most comprehensive methodology and programs for performing PSHA were developed for nuclear power plants, considering the geological, tectonic and seismological conditions of Ukraine. It should be noted that the main methodological provisions developed for nuclear power plants can be successfully used for performing PSHA of other facilities of increased responsibility class. The main purpose of performing PSHA is to estimate peak ground accelerations and obtain generalized response spectra for the design level and maximum design earthquake. PSHA is performed based on an integrated database containing the results of geological, geophysical, geomorphological, tectonic, engineering-geological, and seismological studies. A key element of successful PSHA implementation is the assessment of uncertainties in the source data. The characteristics of the source data and their uncertainties are based on the available information.

Geological structure of the Dnipro River floodplain areas

In today's conditions of the country's development, cities and suburban areas are being built up at a rapid pace, which causes its shortage, especially in cities with a large population. In such conditions, one of the possible solutions for the development of the city is the development of previously unsuitable areas that can be used for construction. Such areas include territories cut by ravines, gullies, wetlands or floodplains, which are flooded with water during floods. Due to the presence of water bodies near the indicated territories, it is possible to protect them from flooding by raising the absolute marks of their surface to non-flooded ones by using alluvial soil by means of hydromechanization. The properties of such new man-made formations differ significantly from natural ones, and sandy soils are used as alluvial soil. In this way, a large number of territories have been created in different countries of the world: Dubai, Japan, China, the USA, etc., which indicates the effectiveness of this method and its practical significance. The article highlights the features of the tectonic structure, geological and geomorphological zoning of the territory of the city of Kyiv. Much attention is paid to the floodplain areas of the Dnieper River, which were formed by alluvial. Such sites were created, as a rule, for new construction and were built up quite quickly with low-rise buildings, the basis for which was alluvial soils. The engineering and geological studies of the sites after alluvial soils and the observation of deformations of the base over time allowed us to establish the basic patterns and rules of construction in such territories. Today, the development of the city actively covers areas created by alluvial soils, on which high-rise buildings, shopping centers, and other buildings are being actively built, the loads from which must be transferred to reliable base. However, depending on the properties of the alluvial soils themselves and the quality and preparation of the base on which they are laid, different types of foundations can be used, the decision on their design is made in each individual case, taking into account the number of floors and the type of buildings or structures.

Comparative Analysis of Fracturing Definitions in Boreholes and Underground Workings

This article presents a comparative analysis of rock mass fracturing at the Karasu gold deposit, located approximately 400 km northwest of Karaganda, Kazakhstan. The analysis is based on core drilling data and measurements from underground workings, including an old mine that was explored and investigated to gather missing information. The spatial characteristics of fractures and their relationship with tectonic faults are identified. The feasibility of using the Rock Quality Designation (RQD) index for classifying fracture systems is assessed. Engineering and geological studies include the identification of major fracture systems and their characteristics using Leapfrog and Rocscience software, chosen for their ease of use and extensive functionality. The stability parameters of open-pit slopes are calculated, considering the physical and mechanical properties of rocks, the degree of fracturing, and the influence of groundwater. Key engineering and geological elements of the rock mass are identified, emphasizing the necessity of integrating fracture data from various sources to improve the accuracy of mine design and ensure the safe operation of open pits. These studies are part of the exploration phase to assess the geological situation and the physico-mechanical properties of these rocks for further quarry design.

Improving the Raman Model for Dravite and Schorl Tourmalines by μXANES Analysis of Iron Oxidation States

ABSTRACTTourmalines, a complex borosilicate mineral supergroup, are significant in geological studies due to their chemical and mechanical stability across various temperature and pressure conditions, making them useful as source rock indicators. A major issue in the characterization of tourmaline composition is the consideration of the iron oxidation state, which can significantly influence the distribution of elements at each site. This study reports the enhancement of a previous model that correlates Raman spectral parameters of dravite–schorl tourmalines with their composition, taking into account the Fe valence state in Y and Z sites measured through micro‐x‐ray absorption near edge structure (μXANES) spectroscopy. Raman spectroscopy was employed in a prior study on these two tourmaline species by correlating peak positions and intensities with differences in the magnesium–iron ratio. However, it was assumed that all iron was in the ferrous oxidation state (Fe2+), which led to a misrepresentation of the Fe3+ content in certain samples. The model has been thus implemented in this work by using μXANES, enabling the accurate quantification of Fe2+ and Fe3+ in dravite–schorl minerals, hence refining Mg/(Mg + Fe2+) ratios for Raman spectral analysis. Results demonstrate the validity of the correlation between Raman peaks in both the fingerprint and OH stretching regions and the magnesium–ferrous iron ratio. Our research confirms that Raman spectrum analysis is an effective method for recognizing tourmalines from the dravite–schorl series and evaluating their composition, including now the evaluation of the Fe2+ and Fe3+ occupancy. By integrating μRaman and μXANES techniques, one can acquire insights into the oxidation state of iron in tourmalines from the dravite–schorl series, thereby enhancing the accuracy of the Mg/(Mg + Fe2+) ratio. The observed linear correlations for P2 peak position, P1/P2 relative intensities, and WOH(3) peak position in the Raman spectrum enable the rapid identification of dravite and schorl tourmalines, as well as the retrieval of relative Mg and Fe2+ contents.

The petrography, metamorphism and deformation history of Neoproterozoic rock from Gida Ayana, Western Ethiopia: implication of tectonometamorphic evolution

The geological study of basement rocks in the Gida Ayana area of western Ethiopia has revealed significant findings regarding the local petrography, metamorphism, and deformation history. The geological evolution of rocks in the area has been analyzed thoroughly through detailed field investigations, overprinting and cross-cutting relationships, and petrographic studies of metamorphic rocks. The findings reveal that the study area experienced polyphase deformations, with at least three ductile deformation phases (D1 to D3) associated with two metamorphic events (M1 and M2), and development of brittle structures such as irregular fractures, joints, and veins. Each type of structure observed in the study area has been discussed in detail, highlighting the formation of F2 folds, S2 foliations, L2 lineations, S3 foliations, F3 folds, and joints. The development of a steep northeast-to-southwest striking foliation S2 gneissic banding and mineral assemblage (Or + Pl + Qtz + Bt + - Sp) indicate that the prograde metamorphism (M1) is synchronous with D2 phase. The alteration products sericite, chlorite, and biotite indicate a retrograde metamorphism (M2) that may have occurred during uplift or D3 shear-zone-related fluid migrations. The regional tectonic setting of Gida Ayana is within the East African Orogen. The relationships between the Gida Ayana metamorphism and deformations with larger tectonic processes, such as continental collisions during the pan-African Orogeny, were discovered. We also analyzed the orientation and features of the deformation structures as well as their associated metamorphic events to offer important insights into the tectonic and metamorphic history of the East African Orogen.

Геоморфометрическое моделирование и картографирование оазиса Бангера (Восточная Антарктида)

As part of a project to create a physical-geographical thematic scientific reference geomorphometric atlas of ice-free territories of Antarctica, we carried out geomorphometric modeling and mapping of the Bunger Oasis (Knox Coast, Wilkes Land, East Antarctica). As a result of processing of the Reference Elevation Model of Antarctica (REMA) fragment including the Bunger Oasis and adjacent glaciers, we for the first time created a series of medium- and large-scale maps of the most important morphometric variables (slope gradient, vertical curvature, horizontal curvature, maximal curvature, minimal curvature, catchment area, topographic wetness index, and stream power index). The obtained morphometric maps describe the topography of the Bunger Oasis in a rigorous, quantitative, and reproducible manner. These maps can be useful for geological, geomorphological, glaciological, soil, ecological, climatic, and hydrological studies of the Bunger Oasis

Enhancing potential fields using stable downward continuation and boundary filters: Application to the Central Highlands, Vietnam

The stable downward continuation method can enhance low amplitude anomalies and improve the resolution of potential fields. However, this method may be affected by the edge effect. In this paper, we improve the downward continuation results by using the cubic Hermite interpolation to extend data. Our synthetic model shows that the proposed extension can provide better estimates, especially at the edges, than using constant values. We further enhance downward continued data using boundary filters where the boundaries obtained from the downward continued data have a higher resolution. The methods are also applied to interpret RTP magnetic and Bouguer gravity anomalies of the Central Highlands (Vietnam), where the RTP magnetic data are determined from the multiple-stage RTP method, while the Bouguer gravity data are calculated using the Parker formula. The spectral analysis of potential fields reveals the depth of shallow sources in the area of about 1 km, which determines the height of the downward continuation. A new subsurface structural map is established for the Central Highlands from the filtered results of downward continued data, which will be a helpful document for detailed future explorations and geology studies of the area.

Palynostratigraphic study (dinoflagellate cysts) of the Callovian–Oxfordian in Essaouira-Agadir Basin, Morocco

Numerous geological studies have focused on the sedimentary basins of the Moroccan Atlantic margin, driven by their potential hydrocarbon and the abundance of well-exposed and rich fossiliferous outcrops. This study is a contribution to palynostratigraphic study of the Essaouira-Agadir Basin. Here we revise previous dating efforts and establish a scale based on dinoflagellate cysts for the Tethyan and Atlantic realms, which would be correlatable with the one established for the entire NW European (subboreal realm). This work presents the preliminary results of the 75-m-thick Iggi N’Tarhzout section, located north of Agadir city, in the Imouzzer Ida Outanane mountain range. The collected samples revealed rich, diverse, and well-preserved dinoflagellate cyst associations, with the occurrence of high-resolution stratigraphic markers. Thus, the upper Callovian is identified at the base of this section by the presence of: Ctenidodinium ornatum, Dichadogonyaulax sellwoodii, Endoscrinium? centriconnata, Systematophora areolata, and Wanaea thysanota. The upper part of the section is attributed to the Upper Oxfordian due to the association composed of: Systematophora penicillata, Endoscrinium galeritum, Systematophora daveyii, Ctenidodinium ornatum and Cribroperidinium granuligerum.

Assessment of Mercury Contamination in the Chalk Aquifer of the Pays de Caux and Its Implications for Public Health (France)

Mercury is naturally present in soils at trace concentrations, but its cycle is increasingly disrupted by anthropogenic activities, which affect its distribution and behavior. Due to its toxic nature, mercury has become a significant focus in environmental and public health policies. Following the detection of mercury anomalies during groundwater quality monitoring at the Pays de Caux study site (France), a comprehensive multidisciplinary research effort was initiated. This included geological and hydrogeological studies aimed at tracking mercury concentrations in piezometric wells and identifying the sources of these anomalies. This study seeks to assess the groundwater quality and characteristics from ten hydrogeological wells. The evaluation will focus on key hydrogeological parameters, including pH, redox potential (Eh), suspended solids, and groundwater levels, as well as a detailed geochemical analysis of elements such as Hg, Fe, Mn, Zn, Pb, and Cu. The mobilization of mercury and other metallic traces elements is strongly governed by environmental factors. Hydrochemical analyses highlight the complex interplay of various parameters that influence the chemical forms and behavior of mercury in both soil and groundwater. The results from the piezometric measurement campaigns (Pz1 to Pz7) have provided crucial insights, enabling the development of hypotheses about mercury’s behavior in the chalk aquifer. It is hypothesized that impermeable areas may trap groundwater for extended periods, leading to the accumulation and abnormal concentration of mercury. This could cause mercury to be intermittently released, potentially affecting the surrounding environment. Mercury concentrations in groundwater are highly sensitive to pH and redox potential (Eh), with low pH and reducing conditions promoting mercury mobilization and the formation of toxic methylated species. The study suggests the chalk aquifer is generally in equilibrium with mercury, but fluctuations in mercury levels between Pz7 and Pz4 are likely due to the heterogeneity of the clay and geological factors such as mineral composition and fracturing. This research provides insights into mercury transfer in heterogeneous environments and emphasizes the need for continuous hydrogeological monitoring, including piezometer readings, to manage mercury dispersion in the aquifer.

Mitigating Leachate Contamination: Geological Investigations at Alue Lim Landfill Area, Lhokseumawe City

Abstract Geological studies are essential for identifying potential pollution in the Alue Lim Landfill Area, Lhokseumawe City. This research focuses on the physical properties of rocks, soil structure, and specific geological layers that influence water movement. The permeability and porosity of rocks are critical factors determining the ease with which leachate penetrates and migrates through geological formations. The study area encompasses the Idi formation sandstone unit (Qpi) and alluvium deposits (Qh). The Idi formation sandstone unit is characterized by fine to medium grain sizes (0.125 - 0.25 mm), interbedded with coarse sand, and exhibits a range from well to poorly sorted, moderately rounded grains with good porosity and permeability. Conversely, the alluvium deposit unit consists of clay, sand, and gravel, where the clay deposits are well-sorted with grain sizes >1/256mm, displaying poor porosity and permeability (range from 35% to 80%), and a clastic texture. The interaction between the permeable sandstone layer of the Idi Formation (aquifer) and the impermeable clay deposits in the alluvium unit (aquiclude) significantly affects leachate movement through the subsurface. Leachate rapidly migrates through the porous materials such as sand and gravel in the sandstone layers, potentially spreading contamination. In contrast, the clay layers act as barriers, limiting and redirecting leachate flow within the alluvium deposits (to the west and south). This research provides crucial insights for recommending management and mitigation strategies to address groundwater pollution in the Alue Lim Landfill Area.

Magnetization of Ultramafic Rocks in the Troodos Ophiolite: Implications for Ridge Axis Serpentinization and Ophiolite Emplacement

AbstractUltramafic rocks exposed in ophiolites are almost always serpentinized, but it is unclear whether the serpentinization occurs during lithospheric formation or subsequent ophiolite emplacement. The Troodos ophiolite offers an opportunity to discriminate between different serpentinization processes, incorporating rock magnetism, paleomagnetism and forward modeling of field magnetic data. Our results revealed distinct magnetic property zones: weakly magnetic mantle Artemis and Olympus zones, and a highly magnetic lower crust Cumulate zone. The Artemis and Olympus samples have magnetite concentrations <1%, magnetic susceptibility <0.01 SI and natural remanent magnetization (NRM) <4 A/m, consistent with low‐temperature serpentinization related to subduction or meteoric water. In contrast, the Cumulate zone rocks have magnetite content up to 8%, magnetic susceptibility up to 0.1 SI and NRM up to 12 A/m, interpreted as high‐temperature serpentinite near a spreading ridge. This ridge‐related serpentinization is supported by the paleomagnetic results. The Cumulate zone has a mean direction of declination = 280°, inclination = 69°, α95 = 16°, comparable to the direction of the lower crust gabbro, which suggests serpentinization‐associated chemical remagnetization during Cretaceous oceanic crust formation. Existing geological, gravity and seismic studies indicate a Pliocene subduction‐related serpentinization event which led to the diapir uplift and surface relief of the Artemis and Olympus zones. Ongoing meteoric water‐related serpentinization following the exposure of ultramafic rocks has caused surface remagnetization of the Artemis and Olympus zones in the current field.

Geological structure and oil and gas potential of the Triassic deposits in the junction zone of the Vilyui syneclise and the Aldan anteclise

Objective. To clarify the geological structure of the Triassic deposits in the junction zone of the Vilyui syneclise and the Aldan anteclise and to identify promising zones and objects for the studied Triassic deposits in terms of oil and gas potential. Materials and methods. The study used previously published sources, deep well logging data, adjusted stratigraphic breakdowns and the results of testing the intervals of the Triassic deposits in deep wells. The well data were used for a comprehensive analysis of new seismic exploration data obtained during seismic exploration work over the past 10 years. Results. Analysis of core description data and well logging records allowed us to describe the lithological structure of the productive Triassic deposits and assume the sediment formation environments. Adjusted stratigraphic breakdowns were tied to seismic time sections at well points. Reflecting seismic horizons were correlated with stratigraphic boundaries. Structural surfaces and thickness maps of the Triassic complex were constructed based on the seismically traced horizons. Wedging-out zones of the Nedzheli, Tagandzha and Monom formations were outlined. Faults were identified and traced using seismic data. A comprehensive analysis of all well and seismic data, obtained during interpretation, identified promising oil and gas zones and objects near the wedging-out lines. Conclusions. The Nedzheli Formation is distributed over a significantly smaller area than other Triassic formations. The areas of distribution of the Tagandzha and Monom formations coincide. In the pinch-out zone, there is a high probability of sand deposits that can serve as hydrocarbon reservoirs. The wedging-out zone is highly likely to contain sand deposits, which are potential reservoirs that, by decreasing thickness, form lithologically limited traps for hydrocarbons. In the western and northern parts of the study area, the oil and gas potential is associated with anticlinal structures complicated by faults. The contours of promising zones and objects can serve to clarify the direction of further geological and geophysical studies of the territory for oil and gas potential.

Inferring 3‐D Rheology of Low‐Viscosity Zone Around Quaternary Volcanoes of NE Japan From Postseismic Deformation of the 2011 Tohoku‐Oki Earthquake

AbstractSeveral geological and geophysical studies suggest the small‐scale presence of low viscosity zone (i.e., LVZ) beneath the Quaternary volcanoes of northeastern Japan. Before the 2011 Mw9.0 Tohoku‐oki earthquake, scientists hypothesized that these LVZs cause localized crustal deformations around the Quaternary volcanoes. However, the deformation‐signals related to these LVZs were too weak to properly understand the LVZ rheology. After the 2011 Tohoku‐oki earthquake, InSAR and Global Navigation Satellite System (GNSS) observations reported significant ground movements around five Quaternary volcanoes including the Mt. Akitakoma, Mt. Kurikoma, Mt. Zao, Mt. Azuma, and Mt. Nasu. Using the early years of postseismic GNSS displacements, we extracted the short‐wavelength components of strain‐rate distribution, which clearly show the localized crustal contraction near the five volcanoes. To explain such spatial pattern of localized contraction, we propose a 3‐D rheological model of LVZs near the five volcanoes, using power‐law Burgers rheology. Most of our modeled LVZs have narrow tops (width of 20–40 km), wide roots (width of 80–100 km), limited arc‐parallel dimensions (≤80 km), and are located at the depth range of 15–55 km in the lower crust‐upper mantle. Based on the localization of postseismic strain rate, newly proposed 3‐D LVZ models highlight an arc‐parallel heterogeneity of subsurface rheology along the volcanic front of northeastern Japan, which is consistent with previously reported clusterization pattern of late Cenozoic calderas and high geothermal gradient near the five Quaternary volcanoes.

Chief Research Achievements of the Earthquake Long-Term Forecast Panel During 2019–2023

Long-term forecast of large earthquakes is an important application of earthquake science to promote earthquake preparedness of people and disaster mitigation. The Earthquake Long-Term Forecast Panel was newly organized as one of the program promotion panels under the 2nd Earthquake and Volcano Hazards Observation and Research Program during 2019–2023. The panel has been promoting studies that advance long-term forecasts of large earthquakes by sharing research prospects and exchanging information on related research topics. The program emphasized developing new long-term forecast methods based on the observation data including geodetic and seismicity data and the physical and statistical models, which lead to not only probabilistic forecasts, but also the development of possible scenarios for major earthquakes at the present. In addition, paleoseismological studies in terms of geological and geomorphological studies as well as archaeological and historical studies were conducted. Some results of the earthquake occurrence history were reflected in the official long-term evaluation by the Headquarters for Earthquake Research Promotion. It is evaluated that our study advanced under the program in the last five years. However, the 2024 MJMA7.6 Noto Peninsula earthquake and other earthquakes that occurred in this program term have raised several problems in earthquake science and hazard mitigation, and it is important to continue and further develop our research in the next program.

Engineering Geological Study to Determine Excavation Methods and Support Systems in Alternative Planning Construction of The Bodri Diversion Tunnel, Kendal District, Central Java Province

Engineering Geological Study to Determine Excavation Methods and Support Systems in Alternative Planning Construction of The Bodri Diversion Tunnel, Kendal District, Central Java Province

Enhancing Tsunami Disaster Awareness: Evaluating the Impact of the i-Share Curriculum in Serang, Indonesia

Abstract Serang City, as an area prone to geological disasters such as landslides and tsunamis, places the Regional Disaster Management Agency (BPBD Serang) as the front guard in disaster mitigation efforts. However, a challenge is the need for a disaster curriculum for schools at any level, especially regarding tsunami disasters. On the other hand, the Geology Study Program at the Universitas Indonesia has responded to this need by developing an innovative tsunami disaster mitigation curriculum, i.e. Innovative Tsunami Hazard Education (i-Share). Therefore, this study aims to assess the effectiveness of i-Share in enhancing participants’ awareness and knowledge of tsunami disasters. Action research approach, as a qualitative method, was employed, with a curriculum tested on 25 teachers and 25 students from various senior high schools in Serang. Each session evaluated participants’ tsunami awareness, with pre- and post-tests measuring curriculum effectiveness. Results show significant enhancement in understanding tsunami disasters. The i-Share curriculum also facilitated the sharing of tsunami-topic learning experiences among peers and family members, fostering a culture of knowledge exchange. In conclusion, while promoting knowledge sharing, the i-Share curriculum successfully improved understanding and awareness of landslide disasters among senior high school educators and students in Serang Regency, Indonesia.

Small Dam Design and Construction for Sustainable Water Resources Management: A Comprehensive Review

Small dams are crucial in water resource management, particularly in regions with water scarcity and climate unpredictability. Despite their cost-effectiveness, the construction of small dams often lacks engineering standards, which raises concerns about their long-term stability and safety. This study reviews the design, construction, stability, and protection of small dams, emphasizing the importance of proper site selection, geological and hydrological studies, and advanced methodologies, such as Geographic Information Systems and multi-criteria decision-making approaches in dam evaluation. Furthermore, the study highlights the significance of detailed planning, material selection, and quality construction to ensure dam longevity. It also discusses the role of modern tools, such as HEC-HMS, HEC-RAS, and GeoStudio in assessing flood risks, seepage, and stability. Inadequate design, particularly in the face of extreme weather events, can lead to dam failures, emphasizing the need for comprehensive planning and rigorous assessments. Through an analysis of various studies and case examples, this paper aims to provide insights into sustainable small dam construction and water resources management practices that ensure their effectiveness and resilience in addressing water scarcity challenges.

A Novel Depth-Weighting Approach Based on Regularized Downward Continuation for Enhanced Gravity Inversion

Gravity inversion plays a crucial role in mineral exploration and resource evaluation, yet conventional depth-weighting methods often impose uniform resolution across all depths and fail to effectively delineate anomaly boundaries. This study presents an innovative attentional depth-weighting matrix based on a regularized downward continuation (RDC) mechanism. First, the observed gravity data are projected to greater depths using RDC, which suppresses high-frequency noise amplification. Next, gradient extrema are extracted from each grid cell to identify anomaly boundaries, forming a constant weighting matrix that enhances the focus on target regions. This matrix is then integrated with traditional depth weighting and a minimum-support focusing factor to optimize the inversion process. The proposed method is validated through two synthetic models, demonstrating improved resolution of deeper targets and more accurate amplitude recovery compared to conventional approaches. Further application to the Dahongshan Copper–Iron Ore region in Yunnan, China, reveals a deep intrusive body at approximately 4–5 km depth, extending east–west with a distinct “U”-shaped geometry. These results, consistent with previous geological studies, highlight the method’s ability to enhance deep anomaly characterization while effectively suppressing shallow noise interference. By balancing noise reduction with improved resolution, this approach broadens the applicability of gravity inversion in geological, geothermal, and mineral resource exploration.

Re-design of a railway tunnel intersected by surface rupture of the Erkenek fault segment during the 6 February 2023 Pazarcik (Mw 7.7) Earthquake (Türkiye)

The T3 Tunnel on the Malatya-Narlı Conventional Railway Route was intersected by the surface rupture during the February 6, 2023 Pazarcık Earthquake (Mw 7.7), and a part of the tunnel was damaged completely. In this study, the investigation results, and re-design of the tunnel, are presented. The T3 Tunnel, which was built in 1933 with interlocking stone masonry lining, was cut by the Erkenek fault, one of the segments of the East Anatolian Fault Zone (EAFZ), and a landslide was triggered around the tunnel portal. Under the influence of these two factors, collapse, and various deformations occurred in the tunnel. To understand the character of the failure, detailed geological, geophysical, and geotechnical studies were carried out in addition to in-situ observations. Subsequently, the tunnel was re-designed and repaired to open the railway to service. For this purpose, a re-design project was developed that included 2-stage engineering solutions including on-tunnel and in-tunnel construction efforts. In the first stage, the portal landslide was rehabilitated using support systems, and in the second stage, tunnel consolidation injection, redesign of the portal structure, and reconstruction of the tunnel support system were carried out. The obtained data and scientific evaluations are presented together with analyses. It is of vital importance that transportation structures continue to function during and after earthquakes. Therefore, the case presented in the study is one of the rare and interesting cases in terms of tunneling literature. The construction efforts in the T3 Tunnel were completed without any problems 6 months after the earthquakes, while more than 30,000 aftershocks continued.