Search Results (68)

Seabed studies are a valuable tool in the investigation of active continental margins, both in volcanic and sedimentary settings. Being an example of a slope-confined sedimentary basin, the “Ammontatura” slope basin has been discussed using multibeam bathymetry and seismo-stratigraphic data matched with previously available cores. Being a significant tectonically controlled slope bounded by the Capri-Sorrento regional fault, the southern slope of the Sorrento Peninsula has been explored employing a dense network of bathymetric profiles. The data have shown the underwater extension of the mainland drainage system, comprising a dense network of submarine gullies, reflecting the onshore drainage system. The northern Ischia debris avalanche deposits have been studied through seismo-stratigraphic data, previously unpublished, whose geologic evolution has been placed within the Quaternary stratigraphic framework of Ischia. This research revealed how several geological events, such as the tectonic phases, the emplacement of erosional and depositional domains, the volcanic eruptions, and the reworking of volcanic deposits, interacted in controlling the sedimentary structure of slope basins. In the Ammontatura slope basin, the tectonic setting has probably controlled its emplacement along a NE–SW trending regional fault, resulting from the submarine prolongation of the Sarno-Sebeto normal fault, while intense reworking of volcaniclastic deposits acted as the main control factor in slope settings. Full article

In the northern Norwegian North Sea, the Lower Paleogene post-rift succession constitutes an underexplored interval with considerable potential for stratigraphic petroleum plays. Nevertheless, predicting its subsurface prospectivity remains hindered by persistent uncertainties in facies architecture, depositional heterogeneity, and reservoir quality. To address these uncertainties, the present study integrates relative geologic time (RGT)-based seismic stratigraphic interpretation, spectral decomposition, sedimentary facies analysis, and litho-saturation assessment, primarily constrained by seismic and well-log datasets, to evaluate the Paleocene post-rift Lista Formation in the northern Norwegian North Sea. The results reveal the presence of Paleocene mass-transport deposit (MTD) complexes associated with axial lobe sandstones of submarine fan systems. These MTD complexes exhibit pronounced vertical and lateral facies transitions into low-density turbidites, debrites, and hemipelagic drapes, together forming an effective stratigraphic framework for hydrocarbon entrapment. Although the Lista submarine-fan sandstones are relatively thin, typically ranging from a few centimeters to decimeters in thickness, they display favorable reservoir characteristics. Litho-saturation analysis indicates preserved porosity and low water saturation (<20%), supporting their potential as effective hydrocarbon storage intervals. Distal fan-lobe sandstones, despite their limited thickness, show encouraging reservoir quality, whereas thicker low stand systems tract (LST) accumulations and time-equivalent carbonate mound complexes appear to have developed within more proximal structural domains. This proximal-to-distal facies organization reflects the dynamic interaction between tectonically inherited accommodation space and sediment-routing pathways during the early Paleocene. Overall, the findings highlight the significant petroleum prospectivity of the Paleocene post-rift succession in the northern Norwegian North Sea. The stratigraphic juxtaposition of sand-prone submarine-fan lobes against hemipelagic sealing intervals, combined with heterogeneity imposed by syn-rift structural inheritance, generates a highly favorable architecture for stratigraphic trapping. More broadly, the integrated workflow presented here enhances the predictive mapping of subtle stratigraphic traps within post-rift successions and provides a robust framework for reducing exploration uncertainty in analogous basins. Full article

This research reveals the coupling mechanism between structural deformation and hydrocarbon accumulation. The Dibei area in the Kuqa Depression represents a key hydrocarbon exploration domain within the northern Tarim foreland basin. Although extensive studies on stratigraphy, sedimentology, and accumulation mechanisms have been conducted, the control of segmented deformation on traps remains poorly understood. Furthermore, the synergistic regulation mechanism involving paleo-uplifts, salt thickness, synsedimentation, and erosion is still ambiguous. Based on high-quality 2D and 3D seismic data, this study integrates tectonic evolution balanced restoration with physical modeling. We conducted two sets of 3D sandbox experiments: “differential paleo-uplift and salt thickness” and “synsedimentation-erosion.” This approach systematically investigates the control of tectonic evolution on trap formation. Results show a strong correspondence between the “subsalt–salt–supra-salt” structural deformation and trap types. The supra-salt layer is dominated by detachment fold traps, whereas the subsalt layer features thrust-fold anticline traps. The basement paleo-uplift governs structural segmentation and trap distribution. Salt thickness modulates strain partitioning and trap stability. Synsedimentation optimizes trap conditions via tectono-sedimentary coupling. Erosional unconformities serve dual functions as both migration pathways and seal beds. These four factors work synergistically throughout the entire petroleum system, from “trap formation–migration–accumulation–preservation.” It enriches the genetic theory of salt-related structures in foreland basins. The findings provide a reference for predicting favorable exploration zones, evaluating trap characteristics, and assessing resource potential in the Kuqa Depression. Full article

The Tuzla Submarine Landslide represents one of the most significant mass-wasting features associated with the active North Anatolian Fault Zone (NAFZ). The failure surface geometry and sediment stratigraphy indicate the presence of a mechanically weak, saturated layer that may become unstable under strong seismic loading. This study presents a comprehensive geotechnical evaluation of the Tuzla Submarine Landslide. Based on regional sediment properties, the landslide was characterized and modeled with an estimated volume of 0.015 km³ and an average slope angle of 14°. The submarine landslide potential was investigated through re-analysis of seismic, geotechnical, and bathymetric datasets. Finite Element Method (FEM) simulations were conducted to model the seismic slope failure. Based on these analyses, the seismic slope displacements, stress distributions, and equivalent plastic strains were identified. The estimated landslide displacements under varying seismic acceleration scenarios corresponding to three major earthquakes ranged between 2.38 m and 4.12 m, depending on the triggering ground motion and slope stability conditions. These findings highlight that reactivation of the Tuzla submarine landslide, potentially triggered by a future large earthquake along the NAFZ, could pose a moderate landslide hazard to the coastal settlements bordering the Marmara Sea. Full article

The depositional environment of the Machów Formation in the central part of the Carpathian Foredeep is still relatively poorly understood. Although lithological variability, facies diversity, and depositional history have been described in many publications, the paleoenvironment of sedimentation and the evolution of individual segments of the sedimentary basin are still not well known. The Miocene complex is difficult to recognize using standard seismic interpretation methods due to cumulative effects of depositional, erosional, and tectonic processes. Progress in science and technology offers new opportunities for the application of high-resolution methods of seismic data interpretation, such as seismostratigraphic interpretation, seismic facies analysis, and seismic geomorphology. The results of seismostratigraphic interpretation of the Machów Formation indicate the presence of numerous depositional sequences of varying thickness and spatial range. The interpretation enabled identification of various types of paleoenvironments, typical for both deeper basin zones (e.g., slope and basin floor fans) and coastal environments. Based on the research conducted, it was concluded that high-resolution 3D seismic data play an essential role in the detection and visualization of lithostratigraphic traps for hydrocarbons, which is important both in exploration and in determining hydrocarbon migration pathways. Full article

This study provides a comprehensive investigation of the sedimentary and tectonic evolution of Kalloni Gulf, a land-locked island embayment in the Northeast Aegean Sea. Information from a high-resolution seismic dataset was used to investigate the Late Quaternary seismic stratigraphy and internal structure of this shallow embayment. Four main seismic units were observed, bound by three key reflectors corresponding to main unconformities. The seismic units are related to periods of sea-level highstand and marine transgression, as well as to lowstand and marine regressions, dating back to the MIS 6 period. The chronostratigraphic framework of the observed units was based on previous work in the wider area and on global sea-level curves. In addition, information was gained regarding the hydrographic network of Kalloni Gulf, before the Holocene gulf flooding as well as during the Late Quaternary. The study also managed to identify faults and fault zones, which are distributed mainly along the southern and eastern margins of the gulf affecting both the gulf entrance physiography and the paleo-terrain of the eastern margin. With regard to specific structural features the fault zones are considered as strike-slip zones with an almost NNE-SSW orientation. These might be the submarine extension of the Aghia Paraskevi dextral strike-slip fault found onshore that dissects Lesvos, which is considered one of the main geohazards for the island. The results of the study are relevant not only for the reconstruction of the regional Quaternary geology, but also for broader research on Late Pleistocene-Holocene environmental change and tectonic-geodynamic processes in the wider northern Aegean Sea region. Full article

Geophysical prospecting has increasingly become a fundamental tool in archaeological research thanks to its ability to rapidly investigate large areas and detect underground structures without impacting the ground. In this study, an integrated geophysical approach was applied to the early Christian archaeological site of Santa Lucia di Mendola, located in southeastern Sicily (Italy). The site is characterised by a complex stratigraphy developed through the exploitation of existing karst features within the limestone lithotype and includes a dating back to the 4th century A.D. hypogeum, surmounted by the remains of a Byzantine Basilica and a small sacristy carved into the rock. A comprehensive geophysical survey was performed to determine a geoarchaeological model of the area. To evaluate and compare the geophysical responses, some of the main geophysical methods used in archaeology were applied: seismic refraction method (SRT), geoelectric method (ERT), frequency domain electromagnetic method (FDEM) and magnetic survey (MAG). The anomalies identified suggest the presence of additional structures dug into the subsoil, probably connected to those currently accessible. This hypothesis is supported by presence of the remains of a wall located at the northern end of the sacristy corridor, which separates this part of the passage from another area visibly filled with rubble. Full article

The effect of an earthquake on any structure is primarily determined by both its inherent properties and the surrounding environmental conditions. When seismic waves pass through different media, their characteristics and properties, such as amplitude, frequency content, and duration can change, thereby changing the seismic response of both soil and structures. The intensity and distribution of seismic waves can be influenced by several of key factors, including the local geology and stratigraphy, irregular topography, existence of man-made structures, and others. Relevant researches and studies have consistently emphasized the significance of the surrounding environment in seismic wave modification. Historical data also shows that similar types of earthquakes can result in varying degrees of damage depending on geographic location. Hence, a thorough understanding of the interaction between seismic waves and the surrounding environment is necessary for achieving precision in seismic design, risk assessment, and proper seismic mitigation strategies. An overview of contemporary research on seismic wave modification and the resulting interaction effects, presenting significant findings and analytical techniques related to phenomena such as soil-structure interaction (SSI) and its extended forms, including structure–soil–structure interaction (SSSI), soil–structure–cluster interaction (SSCI), and site–city interaction (SCI), is presented in this review article. The underlying mechanisms of these interactions are explored in this study and a detailed assessment of fundamental concepts, practical challenges, and methodologies for preventing and mitigating their effects in site-dependent settings is provided. Further, Topographic soil–structure interaction (TSSI) and topographic–structure–soil–structure interaction (TSSSI) are also discussed within a unified framework that considers the combined influence of topography and SSI extensions. This study focuses on the importance of the surrounding environment in influencing ground motion during earthquakes by identifying the complex interactions that affect the seismic response of both surface and underground structures. Some illustrative figures were generated with Microsoft Copilot and subsequently edited and validated by the authors. Full article

Low-lying coastal plains are increasingly threatened by saltwater intrusion, yet the extent of the phenomenon and the role of coastal dune systems remain unevenly assessed. In the northern Adriatic Sea (NE Italy), salinisation has been documented, but systematic, spatially resolved studies are lacking. This work investigates the Belvedere–San Marco relict dune system to assess its hydrogeological function and vulnerability to seawater intrusion. An integrated methodology combining borehole and core stratigraphy, in situ water electrical conductivity (EC) measurements, and multi-method geophysical surveys (FDEM, ERT, GPR, active seismics) was tested. Results reveal a consistent stratigraphy of permeable aeolian sands overlying clay-rich units, with groundwater EC values in the dune sector always remaining well below thresholds for brackish or saline conditions. Geophysical imaging reveals that the dunes are low-conductive bodies contrasting sharply with the conductive surrounding lowlands, thus indicating the persistence of a freshwater lens sustained by local recharge within the dunes. The Belvedere–San Marco dunes therefore act as both freshwater reservoirs and natural hydraulic barriers, buffering shallow aquifers against salinisation. This study demonstrated the applicability of integrated geophysical methods to extensively investigate shallow phreatic aquifers lying a few metres below the surface, and establishes a baseline for monitoring future changes under rising sea levels, subsidence, and increased groundwater exploitation. Full article

While 3D seismic reflection is well established in hydrocarbon exploration at the kilometer scale in relatively simple offshore settings, its application to shallow faulting in continental basins is rare, owing to difficulties in adapting acquisition and processing to rugged terrains and complex near-surface conditions. We present the first high-resolution 3D seismic study of a seismogenic fault in a structurally complex intramontane basin at depths < 200 m. The survey focuses on the Pantano–Ripa Rossa Fault, ruptured during the 1980 Mw 6.9 Irpinia earthquake, the largest Italian event of the past century. This fault cuts across the Pantano di San Gregorio Magno, a small basin filled with Quaternary sediments and showing modest cumulative displacement. Our results demonstrate that in such environments, where morphotectonic analysis and 2D geophysics provide limited constraints, high-resolution 3D seismic imaging is crucial to resolve fault geometry and to assess surface-faulting hazard. The 3D volume reveals a ~35–40 m wide intra-basin deformation zone beneath the 1980 rupture, composed of synthetic and antithetic splays, and highlights lateral variations in fault geometry and stratigraphy. Deformation is distributed and complex, with fault-controlled depocenters, variable sedimentary architectures, and rapid basement-depth changes—features unresolved by 2D data. We infer that the Pantano–Ripa Rossa Fault is relatively young, active since the late Middle Pleistocene, and developed in the hanging wall of the NE-dipping southern basin-bounding fault, challenging previous models that located the master fault along the northern basin margin. Full article

Quantitative seismic characterization of transitional shale gas resources in the Da Ning–Ji Xian area, Ordos Basin, is severely hampered by complex coal-measure stratigraphy and rapid lithological variations. These challenges are critically exacerbated by severe signal attenuation from a thick loess overburden and multiple coal seams, which significantly degrades vertical resolution and undermines the reliability of quantitative interpretation. To surmount these obstacles, this study proposes an integrated, attenuation-centric inversion workflow that systematically rectifies attenuation effects as a foundational pre-conditioning step. The novelty of this study lies in establishing a systematic workflow where a data-driven, spatially variant Q-estimation is used as a crucial pre-conditioning step to guide a robust inverse Q-filtering, enabling a high-fidelity quantitative inversion for shale gas parameters in a geological setting with severe attenuation. The proposed workflow begins with a data-driven estimation of a spatially variant quality factor (Q) volume using the Local Centroid Frequency Shift (LCFS) method. This crucial Q-volume then guides a robust post-stack inverse Q-filtering process, engineered to restore high-frequency signal components and correct phase distortions, thereby substantially broadening the effective seismic bandwidth. With the seismic data now compensated for attenuation, high-resolution shale gas parameters, including Total Organic Carbon (TOC), are quantitatively derived through post-stack simultaneous inversion. Application of the workflow to field data yields an inverted volume characterized by improved structural clarity, sharply defined stratigraphic boundaries, and more robust lithological discrimination, highlighting its practical effectiveness. This attenuation-compensated inversion framework thus establishes a robust and transferable methodology for unlocking high-fidelity quantitative interpretation in geological settings previously deemed intractable due to severe seismic attenuation. Full article

An exposed sedimentary succession, ca 115 m of a total of 1000 m, from the Eastern Carpathian foredeep was, for the first time, analyzed using facies analysis and scale- and time-independent sequence stratigraphy methods to reveal the depositional environment and its cyclic sedimentation. The outcropping deposits, belonging to the Șomuz Formation, dated on the basis of molluscs, foraminifera, and ostracods, are uppermost Volhynian (upper Serravalian). The three recurrent facies associations we have distinguished indicate a storm-dominated shoreface–offshore transition environment. Five-decametre-thick high-frequency sequences (HFS1–5), at most of 4th order, bounded by maximum regressive surfaces, were defined in the studied interval. The maximum thickness of the Volhynian deposits in the area, known both from well sites and outcrops, allowed us to estimate the sedimentation rate at ca 1.5 m/kyr. The fossil content shows that the entire sedimentary succession was deposited in very shallow to shallow water during the whole Volhynian (12.65 - ca 12.01 Ma). The time interval we studied was estimated at ca 75 kyr, so the average time of one HFS is ca 15 kyr. At this scale, considering that both high subsidence and Eastern Paratethys sea-level rise added to accommodation, the sediment supply must have been the main control of cyclic sedimentation, which, in turn, must have been controlled by precession climatic changes in the source area. The estimated time of an HFS is shorter than a precession cycle, but better dating might support or refute this hypothesis. This paper may awaken the interest of the owners of better data, especially from subsurface (seismic, well logs), to complete the data from natural exposures. Full article

Historic masonry churches are highly vulnerable to structural degradation and seismic hazards due to their geometric complexity, material ageing, and lack of detailed construction records. The Church of Santos Juanes in Valencia, a monument of exceptional historical and architectural value, presents these challenges, intensified by centuries of transformations and partial loss of documentation. In this study, we develop a comprehensive methodology that integrates historical research, non-destructive testing (3D laser scanning with Leica Geosystems Cyclone v9.1.1; infrared thermography, commercial software; ground-penetrating radar with gprMax 2016 and GPR-SLICE v7.MT), and advanced finite element modelling (Angle v1). The integrated survey data enabled the creation of an accurate 3D geometric model, the detection of hidden construction elements, and the characterisation of subsoil stratigraphy. Structural simulations under static and seismic loading—considering soil–structure interaction—revealed the high global stiffness of the complex, the influence of the Baroque vault on load distribution, and localised vulnerabilities, particularly in the San Juan ‘O’ façade, which coincide with existing cracks confirmed by thermography. This methodological framework not only advances the diagnosis and conservation of Santos Juanes but also provides a replicable model for assessing and safeguarding other heritage buildings with similar typological and structural challenges. Full article

The central and deep reservoirs of the Wushi Sag in the Beibu Gulf Basin, China, are characterized by structurally complex settings, strong heterogeneity, multiple controlling factors for physical properties of reservoirs, rapid lateral variations in reservoir thickness and petrophysical properties, and limited seismic resolution. To address these challenges, this study integrates the INPEFA inflection point technique and Morlet wavelet transform to delineate system tracts and construct a High-Frequency Stratigraphic Framework (HFSF). Sedimentary facies are identified through the integration of core descriptions and seismic data, enabling the mapping of facies distributions. The vertical constraints provided by the stratigraphic framework, combined with the lateral control from facies distribution, which, based on identification with logging data and geological data, support the construction of a geologically consistent low-frequency initial model. Subsequently, geostatistical seismic inversion is performed to derive acoustic impedance and lithological distributions within the central and deep reservoirs. Compared with the traditional methods, the accuracy of the inversion results of this method is 8% higher resolution than that of the conventional methods, with improved vertical resolution to 3 m, and enhances the lateral continuity matched with the sedimentary facies structure. This integrated workflow provides a robust basis for predicting the spatial distribution of sandstone reservoirs in the Wushi Sag’s deeper stratigraphic intervals. Full article

The Lower–Middle Jurassic of the Kuqa Depression consists of terrestrial clastic deposits containing coal seams and thick lacustrine mudstones, and is of great significance for oil and gas exploration. Based on the comprehensive analysis of core, well-logging, outcrop, and seismic data, the sequence stratigraphy, depositional systems, and the controlling factors of the basin filling in the depression are systematically documented. Four primary depositional systems, including braided river delta, meandering river delta, lacustrine, and swamp deposits, are identified within the Ahe, Yangxia, and Kezilenuer Formations of the Lower–Middle Jurassic. The basin fills can be classified into two second-order and nine third-order sequences (SQ1–SQ9) confined by regional or local unconformities and their correlative conformities. This study shows that the sedimentary evolution has undergone the following three stages: Stage I (SQ1–SQ2) primarily developed braided river, braided river delta, and shallow lacustrine deposits; Stage II (SQ3–SQ5) primarily developed meandering river, meandering river delta, and extensive deep and semi-deep lacustrine deposits; Stage III (SQ6–SQ9) primarily developed swamp (SQ6–SQ7), meandering river delta, and shore–shallow lacustrine deposits (SQ8–SQ9). The uplift of the Tianshan Orogenic Belt in the Early Jurassic (Stage I) may have facilitated the development of braided fluvial–deltaic deposits. The subsequential expansion of the sedimentary area and the weakened sediment supply can be attributed to the planation of the source area and widespread basin subsidence, with the transition of the depositional environments from braided river delta deposits to meandering river delta and swamp deposits. The regional expansion or rise of the lake during Stage II was likely triggered by the hot and humid climate conditions, possibly associated with the Early Jurassic Toarcian Oceanic Anoxic Event. The thick swamp deposits formed during Stage III may be controlled by the interplay of rational accommodation, warm and humid climatic conditions, and limited sediment supply. Milankovitch cycles identified in Stage III further reveal that coal accumulation was primarily modulated by long-period eccentricity forcing. Full article