Geosciences, Volume 12, Issue 12 (December 2022) – 31 articles

This work presents the chronology of the Holocene filling of the Guadalentín Tectonic Depression (Murcia, SE Spain) combining ¹⁴C and OSL age data. This work studies the sediments and paleosols interbedded in the sedimentary sequence between Totana and Librilla, using as reference the Espuña Karting section (Alhama de Murcia), which has been fully sampled for its geochronological analysis. The entire dated sequences record the last c. 20–19 ka BP, although local basal travertine beds extend back to the Late Pleistocene (30–33 ka). Soil morphology and properties from dated paleosols record different environmental crises in SE Spain, but also a progressive aridification throughout the Holocene. The Chalcolithic Paleosol develops soon after c. 4.6–4.0 BP, nearly coinciding with the start of the Meghalayan stage, evidencing a drastic change from relatively humid to arid conditions, coincident with the crisis of the Copper Age civilizations in Spain. The Bronze Age paleosol also developed under arid but relatively more humid conditions, indicating a more important and longer gap in the sedimentary sequence soon after c. 2.5–2.7 ka BP. This stop in the sedimentation are correlative to the first stages of fluvial incision at basin center locations and the desiccation and fragmentation of the ancient wetlands coinciding with the collapse of the Bronze Age civilizations in SE Spain (Argaric Culture). During the Ibero-Roman Humid Period (IRHP), c. 2.6–1.6 ka BP, the last pedogenic cycle occurred under relatively humid conditions. This preluded the progressive establishment of exorheic fluvial environments as well as a period of paleoseismic activity in the area around 2.0–1.8 ka BP. Full article

Benthic foraminiferal assemblages have been studied at 11 sediment surface samples located in the Neretva Channel covering the delta habitat and the adjacent open sea areas. The major objective of the investigation was to explore the main environmental parameters affecting the benthic foraminifera compositional changes. To this end, a statistical approach was applied that integrates micropaleontological data with physical, geochemical and sedimentological parameters (total organic carbon and grain size). Statistical analyses identified four distinct groups (cluster A1, A2, B1, B2) corresponding to different environmental settings. Cluster A1 groups samples under Neretva river influence and is characterized by Aubignyna perlucida, Nonionella turgida, Eggerelloides scaber and Rectuvigerina sp.; species able to live in organic-matter-rich sediments and in a wide range of oxygen content. Cluster A2 includes samples distant from the fluvial outlet and samples along the NW coast partially influenced by the Neretva river plume. In these environmental conditions, Ammonia beccarii, Bulimina marginata, Nonionella turgida and Textularia sp. resulted as the most characteristic taxa. Cluster B1 distinguishes the deepest stations which are in connection with the open Adriatic Sea. Here Asterigerinata mamilla, Buccella granulata, Cibicides group, Reussella spinulosa and Textularia sp. reach their maximum abundance associated with coarse-grained sediments. Cluster B2 groups samples collected in the inner bay of the southernmost sector of the studied area characterized by silt and clay and a negligible influence by river inputs. The benthic microfauna is principally composed of Miliolids, Porosononion granosum and Textularia sp. Full article

The current prototype of a fully automatic earthquake tsunami hazard assessment system, “Tsunami Observer”, is described. The transition of the system to the active phase of operation occurs when information about a strong earthquake (M_w ≥ 6.0) is received. In the first stage, the vector field of coseismic displacements of the Earth’s crust is calculated by using the Okada formulas. In the calculations, use is made of data on the coordinates, the seismic moment, the focal mechanism, and the depth of the earthquake, as well as empirical patterns. In the second stage, the initial elevation of the water surface at the tsunami’s focus is determined with the vector field of coseismic displacements of the bottom and the distribution of ocean depths, and the earthquake’s potential energy is calculated. In the third stage, the intensity of the tsunami is estimated on the Soloviev–Imamura scale in accordance with the magnitude of the potential energy by using the empirical relationship that is obtained as a result of a statistical analysis of historical tsunami events. In the final stage, if the energy exceeds the critical value of 10⁹ J, a numerical simulation of the tsunami is performed, which allows the determination of the predominant directions of wave energy propagation and estimation of the runup height on the nearest coast. In this work, data on the operation of the system over the last 3 years are presented. Full article

Upward surface movement or uplift has been extensively observed above abandoned and flooded deep coal mines, which used the longwall mining method, i.e., a caving method. Detailed analysis of satellite measurements indicated that the process of uplift is one of the more complex phenomena in ground control. The observed uplift is linked to the flooding of the underground infrastructure and rock mass. This was confirmed by conducting analytical calculations. The distribution of water pressure at the end of the mining phase and their increase during the flooding is an important aspect in all estimations. The main objectives of the study are to compare the impact of various hydrogeological conditions of this distribution at the start of the flooding phase and to select the most realistic one. They range from a zero-water pressure to a linear decrease from the top to the bottom longwall panel. Different scenarios of how the water pressures change as a function of time are also compared, i.e., from filling an open reservoir from bottom to top, to a systematic change in the linear downward trend. The main conclusion is that a linear trend, i.e., the original assumed scenario, is the best option in comparison to the other scenarios evaluated. It provides the best fit between the estimated uplift values and the large amount of remote sensing measurements along north–south transects in the Belgian Campine coal basin. Full article

The establishment of quality requirements of clay-based products, for medicinal, wellness, and aesthetic purposes, is mainly sustained by the good interactions between the clay-based formulation and the skin. The release of ionizable elements and their availability to percutaneous absorption should be, ideally, physiologically effective during passive percutaneous absorption. Clay-based products are promoted in the European market as therapeutic clays or aesthetics, which is labeling that combines characteristics of medicinal products along with cosmetics. Different countries regulate these products under different legal frameworks. This study focuses on the mineralogical, chemical, and technological characterization of some clay-based products available on the market, designed for topical use, framed in the peloids concept, and claimed as natural products. The main goals are to contribute to the establishment of clay-based products quality criteria as reliable scientific information, aiming for the compliance of intended use, the information for the potential health hazards and toxicological effects of clay-based products, and the distinction in what concerns therapeutic compliance and aesthetic or wellbeing product certification. There were 13 clayed products for cosmetic purposes, available online and in commercial stores, together with three thermal peloids, that were studied. Mineralogical composition of the 16 studied samples reveals a polymineralic association with the presence of variable quantities of quartz, calcite, and feldspars, whereas clay minerals are not predominant and characterized by the presence of clay-based fraction content, composed mainly by illite, smectite, and kaolinite in variable amounts and with several mineral associations. The clay-based products contain median values of 17 ppm As, 315 ppm Ba, 79 ppm Cr, 11 ppm Co, 29 ppm Pb, 26 ppm Ni, and 62 ppm Zn. One sample presented 4.1 ppm of Cd. The studied samples have safety concerns about specific limits of As, Ba, Cd, Cr, Co, Pb, Ni, and Zn which are above the regulated avoidable limits. Samples’ pH is out of range of skin’s natural pH as well. Full article

Volatiles transported from the Earth’s interior to the surface through permeable faults provide insights on the gas composition of deep reservoirs, mixing and migration processes, and can also be applied as gas-geothermometer. Here, we present carbon (δ¹³C), hydrogen (δ²H) and nitrogen (δ¹⁵N) isotopic data of CO₂, CH₄, and N₂ from gas samples collected from the Kızıldere and Tekke Hamam geothermal fields, located along the eastern segment of the Büyük Menderes Graben, Turkey. The stable isotopic composition of carbon (δ¹³C) ranges from +0.30 to +0.99‰ (PDB) for CO₂ from Kızıldere and is slightly more variable (−0.95 to +1.3‰) in samples from Tekke Hamam. Carbon isotope data in combination with CO₂/³He data reveal that ~97% (Tekke Hamam) to ~99% (Kızıldere) of CO₂ derives from limestone sources, with the residual CO₂ being magmatic in origin with no evidence for CO₂ from organic sources. The slightly higher contribution of limestone-derived CO₂ in Kızıldere, compared to Tekke Hamam can be attributed to the higher temperatures of the Kızıldere reservoir and resulting amplified fluid–limestone interaction, as well as helium depletion during phase separation for Kızıldere samples. In contrast to the carbon isotopic composition of CO₂, the δ¹³C values of methane from Kızıldere and Tekke Hamam are clearly distinct and vary between −23.6 and −20.8‰ for Kızıldere and −34.4 and −31.7‰ for Tekke Hamam, respectively. The δ²H-CH₄ composition is also distinct, measured as −126.7‰ for Kızıldere and −143.3‰ for Tekke Hamam. CO₂-CH₄ carbon isotope geothermometry calculations based on the isotopic fractionation of δ¹³C between the dominant component CO₂ and the minor component CH₄ reveals temperatures 20–40 °C and 100–160 °C higher than the bottom–hole temperatures measured for Tekke Hamam and Kızıldere, respectively. Based on the CO₂-CH₄ carbon isotope disequilibrium, unusual high methane concentrations of ~0.3 to 0.4 vol.-% and CH₄/³He-δ¹³C-CH₄ relationships we suggest thermal decomposition of late (Tekke Hamam) to over-mature (Kızıldere) organic matter and, to some extent, also abiogenic processes as principal source of methane. The N₂/³⁶Ar ratios of most samples reveal the existence of a non–atmospheric nitrogen component within the gas mixture issuing from both fields, in addition to a constant contribution of atmospheric derived nitrogen accompanied into the system via the meteoric recharge of the geothermal system. Based on the δ¹⁵N isotopic ratios (varying between −4.44‰ and 4.54‰), the non–atmospheric component seems to be a mixture of both sedimentary (crustal organic) and mantle nitrogen. The thick Pliocene sedimentary sequence covering the metamorphic basement is the likely major source for the thermogenic content of CH₄ and crustal N₂ gas content in the samples. Full article

In this study, we analyze the fault and fracture network of the Middle Triassic carbonate platform of the Lastoni di Formin (Italian Dolomites, Italy). The reconstruction of the deformation history is of primary importance for a full comprehension of the present structural setting of this carbonate platform. The huge dimensions of the carbonate body and superb exposure of its vertical cliffs and gently dipping top plateau make the Lastoni di Formin platform an ideal outcrop to integrate traditional fieldwork with Digital Outcrop Modelling analysis. The results of the structural studies partially confirm that the present-day fracture pattern is the result of differential compaction-induced deformation that generated WNW-ESE-trending extensional fractures and normal faults, perpendicular to the direction of progradation of the platform. Successively, extensional tectonics, likely related to the Jurassic rifting phase, led to the formation of NNW-SSE striking fractures and westward-dipping normal faults. A Neogene compressional tectonic event, characterized by N-S to NW-SE crustal shortening, deformed the platform, essentially with strike-slip structures. Full article

Conventional and varietal heavy mineral studies of the earliest Eocene Hermod S2 Member (Mbr) sandstones in the Greater Alvheim area of the northern North Sea have revealed marked lateral variations and more subtle vertical evolution in provenance signature. Major variations are of geographic rather than stratigraphic nature as biostratigraphy reveals that all investigated sandstones are coeval. The provenance variations show an organized pattern, with sandstones in the north showing a different signature than those in the south. The position of the sandstones relative to the East Shetland Platform (ESP) is inferred to be the main control on provenance, with sediment input from at least two different point sources. Sediment supplied from both catchments is predominantly recycled in nature, given the mineralogical maturity of the heavy mineral assemblages, consistent with the evidence for widespread Permo-Triassic and Devonian sediments on the ESP. However, some direct supply from metasedimentary (Moine and Dalradian) basement is implied by the sporadic occurrence of unstable minerals. The southern catchment incorporated a greater exposure of Permo-Triassic sandstones than the northern catchment. The Permo-Triassic part of the catchment can be reconstructed as comprising equivalents of the Foula and Otter Bank sandstones present to the west of Shetland, with the majority of the Foula section having been stripped off prior to Hermod S2 deposition, exposing Otter Bank equivalents for erosion and redeposition. However, remnant Foula-like sandstones remained exposed further south on the ESP until at least the earliest Eocene since Foula-type garnet signatures are found in the Forties Sandstone Mbr of the central North Sea. In addition to lateral differences, stratigraphic evolution of provenance can also be detected in the Hermod S2 Mbr, with variations in key provenance-sensitive parameters related to a sea-level rise that reduced the extent of alluvial storage and altered the geological framework of the hinterland. Full article

Soil liquefaction or instability, one of the most catastrophic phenomena, has attracted significant research attention in recent years. The main cause of soil liquefaction or instability is the reduction in the effective stress in the soil due to the build-up of pore water pressure. Such a phenomenon has often been thought to be related to the undrained shearing of saturated or nearly saturated sandy soils. Notwithstanding, many researchers also reported soil instability under a drained condition due to the reduction in lateral stress. This condition is often referred to as the constant shear drained (CSD) condition, and it is not uncommon in nature, especially in a soil slope. Even though several catastrophic dam failures have been attributed to CSD failure, the failure mechanisms in CSD conditions are not well understood, e.g., how the volumetric strain or effective stress changes at the triggering of flow deformation. Researchers often consider the soil fabric to be one of the contributors to soil behaviour and use this parameter to explain the failure mechanism of soil. However, the soil fabric is difficult to measure in conventional laboratory tests. Due to that reason, a numerical approach capable of capturing the soil fabric, the discrete element method (DEM), is used to investigate the CSD shearing mechanism. A series of simulations on 3D assemblies of ellipsoid particles was conducted. The DEM specimens exhibited instability behaviour when the effective stress paths nearly reached the critical state line. It can be clearly observed that the axial and volumetric strains changed suddenly when the stress states were close to the critical state line. Alongside these micromechanical observations, the study also presents deeper insights into soil behaviour by relating the macro-observations to the micromechanical aspect of the soil. Full article

The Earth’s revolution is modified by changes in inclination of its rotation axis. Its trajectory is not closed and the equinoxes drift. Changes in polar motion and revolution are coupled through the Liouville–Euler equations. Milanković (1920) argued that the shortest precession period of solstices is 20,700 years: the summer solstice in one hemisphere takes place alternately every 11,000 year at perihelion and at aphelion. Milanković assumed that the planetary distances to the Sun and the solar ephemerids are constant. There are now observations that allow one to drop these assumptions. We have submitted the time series for the Earth’s pole of rotation, global mean surface temperature and ephemeris to iterative Singular Spectrum Analysis. iSSA extracts from each a trend a 1 year and a 60 year component. Both the apparent drift of solstices of Earth around the Sun and the global mean temperature exhibit a strong 60 year oscillation. We monitor the precession of the Earth’s elliptical orbit using the positions of the solstices as a function of Sun–Earth distance. The “fixed dates” of solstices actually drift. Comparing the time evolution of the winter and summer solstices positions of the rotation pole and the first iSSA component (trend) of the temperature allows one to recognize some common features. A basic equation from Milankovic links the derivative of heat received at a given location on Earth to solar insolation, known functions of the location coordinates, solar declination and hour angle, with an inverse square dependence on the Sun–Earth distance. We have translated the drift of solstices as a function of distance to the Sun into the geometrical insolation theory of Milanković. Shifting the inverse square of the 60 year iSSA drift of solstices by 15 years with respect to the first derivative of the 60 year iSSA trend of temperature, that is exactly a quadrature in time, puts the two curves in quasi-exact superimposition. The probability of a chance coincidence appears very low. Correlation does not imply causality when there is no accompanying model. Here, Milankovic’s equation can be considered as a model that is widely accepted. This paper identifies a case of agreement between observations and a mathematical formulation, a case in which an element of global surface temperature could be caused by changes in the Earth’s rotation axis. It extends the range of Milankovic cycles and resulting global temperature variations to shorter periods (1–100 year range), with a major role for the 60-year oscillation). Full article

The French region adjacent to the Mediterranean basin is vulnerable to hydrological risks generated by convective precipitation in the form of heavy rainfall and conditioned by the configuration of the relief. These risks are driven by the increase in sea water temperature over the last half century, which itself has been more pronounced since 1990. The statistical analysis on the frequency of rainfall intensity in a 24 to 48 h interval, correlated with the NAO, WMOI and SSTMED indices shows a recrudescence of rainfall amounting to more than 100 mm, which leads to the genesis of floods and flash floods. Furthermore, there has been a higher frequency of floods and disasters in this period. The intensity of material and human damage recorded following such local Cévennes-type phenomena is also due to urban development and population growth. Full article

Lefkada and Corfu old towns are located in the western part of Greece, in the Ionian Sea. Their proximity to the Hellenic subduction zone (HSZ) is the reason for their intense seismicity. The main goal of this study was the estimation of the geotechnical characteristics of the subsurface, with the contribution of applied geophysical techniques. Therefore, seismic refraction tomography (SRT) and multichannel analysis of surface waves (MASW) were applied. A total of thirty-three (33) seismic and geoelectrical profiles were performed in both towns in order to evaluate the geotechnical characteristics of the subsurface formations. Additionally, subsurface resistivity distributions were investigated with the application of electrical resistivity tomography (ERT). Some important elastic moduli were calculated through the combination of estimated seismic wave velocities and laboratory density measurements. The horizontal distribution of seismic velocities and mechanical properties (σ, E, K, G) of Corfu town was illustrated in maps, for the depth of 5 m. The geophysical interpretation also revealed that Lefkada’s subsurface consists of only one compact geological formation, with little or no variation of its geophysical-geotechnical characteristics. Beyond that, the ground type classifications for the two towns were determined according to the European Committee for Standardization Eurocode 8, based on V_S30 values. Full article

The purpose of this paper is to propose the quasi-linear theory of tsunami run-up and run-down on a beach with complex bottom topography. We begin with the one-dimensional nonlinear shallow-water wave equations, which we consider over a beach of complex geometry that can be modeled by a piecewise continuous function, along with several natural initial and boundary conditions. The primary obstacle in solving this problem is the moving boundary associated with the shoreline motion. To avoid this difficulty, we replace the moving boundary with a stationary boundary by applying a transformation to the spatial variable of the computational domain. A characteristic feature of any tsunami problem is the smallness of the parameter $\epsilon ={\eta }_0/h_0$, where ${\eta }_0$ is the characteristic amplitude of the wave, and $h_0$ is the characteristic depth of the ocean. The presence of this small parameter enables us to effectively linearize the problem by using the method of perturbations, which leads to an analytical solution via an integral transformation. This analytical solution assumes that there is no wave breaking. In light of this assumption, we introduce the wave no-breaking criterion and determine bounds for the applicability of our theory. The proposed model can be readily used to investigate the tsunami run-up and draw-down for different sea bottom profiles. The novel particular solution, when the seafloor is described by the piecewise linear function, is obtained, and the effects of the different beach profiles and initial wave locations are considered. Full article

In the last decades, the application fields of exploration geophysics have considerably broadened, reinforcing the relevance of exploration geophysics courses both within geosciences and non-geosciences degrees. Among these courses, those with a hands-on, place-based pedagogical approach and aligned with problem-based and case-based learning methodologies have proven to be particularly successful in regard to addressing the recognized difficulty that students experience in transferring their classroom knowledge to the field environment. In this article, we report a theoretical–practical module for the teaching of exploration geophysics methods to undergraduate non-geoscience major students, and in particular, to forestry engineering students. The in-field activity, based on a combination of Electrical Resistivity Imaging (ERI) and electromagnetic induction (EM) methods, was complemented with in-class sessions covering the fundamentals of these methods and Archie’s equation, software usage, data analysis and interpretation, and critical in-group discussions. This situated, context-rich teaching and learning example may be reproduced in other teaching institutions to provide technology-driven educational experiences in their curricula, helping students recognize the relevance of the abovementioned geophysical methods to address research questions beyond geology. Full article

The soils of uplands and partially isolated landforms located in the central Volga region were investigated in terms morphology, diversity and geogenic factor specificity. The Samarskaya Luka area is characterized by extreme spatial inhomogeneity and contrast of geogenic (lithological and topographic) conditions, and at the same time is located on the ecotone-transitional border of several natural zones. This territory is a part of two federal protected areas because of its peculiar nature. It is established that the diversity of geogenic (geological and topographic) conditions leads to the differentiation of the soil cover. Key soil types are presented by Leptosols, Cambisols, Retisols, Chernozems, Fluvisols and Technosols. By the example of the recognized upland macrolandscape, it is shown that the usual gradual course of soil zonation significantly changes due to the transformation of the soil-forming potential of the environment. The obtained data can be used for further regional verification of soil taxonomy. In addition, since the role of parent materials increases as they move from the west to the east of the East European Plain, parameterization of the role of this process becomes particularly important. Information about the diversity of chemical parameters and the granulometric composition of the key soil types of the studied area is also given. Full article

Epidote group minerals are one of the three most abundant kinds of heavy minerals in orogenic sediments, the other two being amphibole and garnet. They resist diagenesis better than amphibole and resist weathering in soils better than garnet. Their chemical composition and optical properties vary markedly and systematically with temperature and pressure conditions during growth. Useful information on the metamorphic grade of source rocks can thus be obtained by provenance analysis. In this study, we combine optical, SEM–EDS, and Raman analyses of nine standard crystals of epidote group minerals collected from different rock units exposed in the European Alps and Apennines and develop a Raman library for efficient discrimination of epidote, clinozoisite, zoisite, and allanite by establishing clear user-oriented relationships among optical properties, chemical composition, and Raman fingerprint. This new library allows us to distinguish and reliably determine, directly from their Raman spectrum, the chemical compositions of epidote group minerals during routine heavy mineral analyses of sand/sandstone and silt/siltstone samples down to the size of a few microns. The validity of the approach is illustrated by its application to 41 Bengal Fan turbidites collected from five cores during IODP Expedition 354 and ranging in grain size from medium sand to fine silt. Full article

The present research illustrates the application of a methodological approach to studying the stress–strain distribution in a marble quarry of the Apuan Alps mining area (Italy). This study has been carried out in the framework of a project involving the University of Siena and the UOC Ingegneria Mineraria—USL Toscana Nord-Ovest, Tuscany Region. This stress–strain analysis aims foremost to monitor the slope stability conditions to guarantee a safe workplace for the personnel involved in mining activities, and to enable more sustainable long-term planning for excavation and production. The involved survey activities are as follows: (i) terrestrial laser scanning; (ii) engineering–geological data mapping; and (iii) in situ marble stress measuring through four CSIRO-type cell tests executed in different locations and at various depths within the underground excavation walls. The gathered data converged into numerical models of the quarry, both in 2D (DEM) and 3D (FEM), calibrated by in situ stress results through a rigorous back analysis assessment using least squares procedures. The created models represent a valuable tool for the identification and securing of risk areas and for future excavation planning in respect of the site efficiency and safety. Full article

Change in sea levels, be they isostatic or eustatic, impact humans and the paleogeography they inhabit. In this paper we examine paleogeography at Iqaluktuuq, a section of the Ekalluk River, Victoria Island, Nunavut, between Tahiryuaq (Ferguson Lake) and Wellington Bay. The area’s isostatic rebound impacted the Ekalluk River’s development and the use of the area by two essential subsistence resources, Arctic char (Salvelinus alpinus) and caribou (Rangifer tarandus). This, in turn, impacted the choices of Pre-Dorset, Middle and Late Dorset, and Thule/Inuit people regarding site locations. A new relative sea-level curve developed using calibrated radiocarbon dates on marine shells and terrestrial material from archaeological sites is produced for Iqaluktuuq. Based on the data, large scale (1:50,000) paleogeography maps are presented for the period of human occupation of Iqaluktuuq, 3100 calibrated years Before Present (B.P. cal) to present, revealing how paleogeography impacts people’s settlement choices. Full article

Currently recognised lithospheric models hypothesise the non-existence of a lithospheric slab (a so-called slab gap) in the area of the Northern Dinarides, and the possible existence of a shallow slab in the Southern Dinarides. These geological models are mostly based on previous regional and global 3D velocity models obtained from teleseismic tomography. Recent local tomographic models providing a good resolution have regularly shown the existence of a fast anomaly underneath the entire Dinarides, directly indicating the existence of a lithospheric slab. To avoid interpretation pitfalls and increase reliability, forward seismic modelling based on new tomographic models was performed. Seismic modelling indicates a continuous lithospheric slab along the entire Dinarides in the shallow mantle, but it is not continuous vertically. In the Northern Dinarides, the shallow lithospheric slab extends at least to a depth of 150 km. In the Southern and Central Dinarides, there is a deep fast anomaly that can be interpreted in two ways due to the weak vertical resolution of teleseismic tomography. The first model suggests a steeply dipping continuous Adriatic lithospheric slab whereas the second model shows that the slab consists of two separate blocks, meaning that the deeper block was formed by delamination of the Adriatic lithospheric slab. Due to a similar correlation between the inverse velocity models for the synthetic model and the observed data, preference is not given to any model. The second model could indicate two independent Dinaridic subduction phases, as opposed to viewing subduction as a single long process during the geological past. Full article

Electrical Resistivity Tomography (ERT) is a robust and well-consolidated method largely applied in near-surface geophysics. Nevertheless, the mapping of the spatial resistivity patterns of the subsurface at a depth greater than 1 km was performed in just a few cases by the ERT method, called deep ERT (DERT). Since, in many cases, the term DERT was adopted with ambiguity for geoelectrical explorations varying in depth within a range of 0–500 m, the main goal of this review is to clearly define the DERT method, identifying a threshold value in the investigation depth. The study focuses both on the purely methodological aspects (e.g., geoelectrical data processing in low noise-to-signal ratio conditions; tomographic algorithms for data inversion) and on the technological features (e.g., sensor layouts, multi-array systems), envisaging the future directions of the research activity, especially that based on machine learning, for improving the geoelectrical data processing and interpretation. The results of the more significant papers published on this topic in the last 20 years are analyzed and discussed. Full article

Built in the early 18th century on the banks of the Saint-François River (Quebec, QC, Canada), the fortified Jesuit mission of Saint-François-de-Sales was an important Abenaki centre during the colonial period. Between 2010 and 2021, archaeological excavations conducted by the Waban-Aki Nation led to the discovery of the mission’s remains at the Fort Odanak site (CaFe-7) in the historical centre of Odanak (Quebec, QC, Canada), and revealed numerous pit features likely used for storage or refuse disposal. A sedimentological and micromorphological investigation was undertaken in two areas of the site to identify the function and use of four pit features and to clarify site formation and evolution over time. Our study indicates that all pit features were used as refuse facilities prior to abandonment, but two of them were possibly used for storage. Chronological (¹⁴C) results indicate that Indigenous people frequented the site during the 16th century, before the establishment of the Jesuit mission, and that an initial domestic Abenaki occupation occurred during the second half of the 18th century in one of the sampled sectors. The use of traditional pit features by the Abenaki of Odanak seems to have persisted into the late 19th century. Full article

The reuse of vintage datasets which were acquired in the 20th century can pose challenges for modern geophysical modeling due to missing detailed preprocessing information, significant uncertainties, or lack of precise tracking, etc. Nevertheless, they are often the only available datasets in a target region. We explore here the potential of such vintage airborne geophysical datasets (magnetics, AEM, radiometrics) to detect the location and dip direction of geological faults, using a non-modeling interpretation approach based on multiple GIS tools. We apply our approach in a geologically well-known region where four different types of faults are mapped. The applicability of the tools used in this study depend on the geological setting of each fault and is evaluated based on the comparison with geological and—where available—with modeling data. In general, the GIS tools, especially used on a combination of datasets, show reliable results concerning the location and strike of faults, and even seem to be able to predict the dip direction of a fault. Full article

The assessment of rock outcrops’ predisposition to the main possible kinematisms represents the preliminary step of stability analysis: Markland’s tests for sliding and toppling constitute a milestone due to the ease of use and interpretation of results. Orientation and friction angles of the main discontinuity sets and orientation of rock faces are required as input to perform the test on a stereonet graphically. However, for natural outcrops, the orientation of rock faces could vary significantly, and the test should be performed assuming all the representative ones. To speed up this process, the authors set up an automatic procedure based on the GIS environment working principles and developed it in Matlab language. Main discontinuity sets orientation and relative friction angles, along with slope and aspect data representing the rockface orientation of the considered outcrop, are the input data. The slope and aspect data are in GeoTIFF format, the most common format for georeferenced raster files employed in a GIS environment. The Matlab code performs Markland’s tests for planar and wedge sliding and flexural toppling, considering all the possible sets or intersections of sets, and provides the output with the same extent and georeferencing of the input data. The outputs are a series of GeoTIFF raster files describing the result for each kinematism separately and globally, which can be imported directly into GIS. The global results can also be used to map source areas for 3D rockfall numerical simulations. The code was validated through a case study by comparing its results with those obtained by performing the conventional tests singularly on a number of significant rock faces. The results obtained in the case study show that the algorithm produces reliable results consistent with those provided by traditional methods. Full article

We reassess the architecture and tectonic history of the Western Alps based on recent knowledge developed at rifted margins. First, we replace the main Alpine units of our study area into a synthetic rifted margin template based on diagnostic petrologic, stratigraphic, and structural criteria. We find that some units previously attributed to the internal part of the thick-crusted Briançonnais domain may rather derive from the thin-crusted Prepiemonte hyperextended domain. We assert that the Briançonnais and Prepiemonte domains were separated by a mega-fault scarp. Second, we revisit the Paleogeography of the Alpine Tethys, suggesting that the Briançonnais was a ribbon of little thinned continental crust between two overstepping en-échelon rift basins, namely the Valais domain to the northwest and the Piemonte domain to the southeast. We affirm that this uneven-margin architecture can explain most of the Western Alps’ complexity. In our kinematic model, convergence between Adria and Europe was mainly accommodated by strike-slip movements in the Western Alps until the late Eocene. Orogeny began with the reactivation of the mega-fault scarp between the Briançonnais and Prepiemonte domains, which we name Prepiemonte Basal Thrust. Once hard collision started, the main shortening stepped inboard into the Valais/Subbriançonnais domain along the Penninic Basal Thrust. Full article

In this study, we investigated the structural evolution of the Vértessomló (VT) Thrust and the Környe-Zsámbék (KZ) Fault, which are located in the Transdanubian Range in the center of the Miocene Pannonian back-arc basin. Our study is based on surface and well data. The Transdanubian Range was located on the Adriatic passive margin during the Late Triassic, where a thick succession of platform carbonates was deposited. Intercalations of intraplatform basin deposits occur in the eastern part of the study area. South-directed thrusting and the formation of the VT Thrust took place during the Cretaceous, related to the Austroalpine orogeny. Asymmetric half-grabens were formed during the Eocene in the hanging wall of the segmented dextral normal KZ Fault. The geometry and kinematics of the KZ Fault were influenced by the pre-existing VT Thrust located in the Mesozoic basement of the Paleogene sub-basins. These Eocene half-grabens suffered mild inversion due to the dextral reverse reactivation of the VT Thrust and the KZ Fault during the Oligocene–Early Miocene. The geometry of Miocene normal faults indicates that the VT-KZ Fault system was an active transfer fault during the Miocene extension of the Pannonian Basin, as well. We found a positive correlation between the rheology of the Triassic basement and the mode of Paleogene fault reactivation. Our results show that reactivation of the pre-existing thrust took place along that segment, where the Triassic basement is made up of homogeneous platform carbonates. In contrast, a diffuse fault zone developed, where the Triassic basement is represented by the weak layers of intraplatform basins. Full article

This study investigates the contribution of global geopotential models which are calculated with GOCE satellite mission data to the improvement of gravimetric geoid models in Turkey. In this context, direct (DIR), time-wise (TIM), space-wise (SPW), and GOCO satellite-only model series were considered. The research was carried out in two parts. The first part includes the validation of models in each series at 100 homogeneously distributed GNSS/leveling stations over the country utilizing spectrally enhanced geoid heights to determine the best performing model and its optimal expansion degree. According to obtained statistics, the TIM-R6 model was selected as the best model with an optimal expansion degree of 204. In the second part, the TIM-R6 model up to 204 degree/order was linearly blended with EGM2008 to obtain an improved version up to 360 degree/order of expansion. To clarify the contribution of the linearly blended model to the improvement of the regional geoid model, the gravimetric geoid models were computed adopting TIM-R6 up to 204 degree/order and its improved version up to 360 degree/order as reference models. To further emphasize the contribution of the GOCE mission’s data, the gravimetric geoid computations were repeated relying on EGM2008 up to 204 and 360 degrees of expansions, since EGM2008 does not contain GOCE data. In addition, we computed gravimetric geoids based on another combined model that includes GOCE mission data, the EIGEN-6C4 model. The calculated regional geoids were compared to each other and validated using GNSS/leveling data set. The obtained results revealed a ∼23% improvement in regional geoid model accuracy when the blended GOCE-based geopotential model was used as a reference. In addition, the results of this study presented the significance of GOCE contribution to mapping the gravity field in Turkey. The best accuracy obtained from this study was 7.7 cm for the Turkey geoid. Full article

With the recent push for a transition towards a climate-resilient economy, the demand on marine resources is accelerating. For many economic exploits, a comprehensive understanding of environmental parameters underpinning seabed morphodynamics in tidally-dominated shelf seas, and the relationship between local and regional scale sediment transport regimes as an entire system, is imperative. In this paper, high-resolution, time-lapse bathymetry datasets, hydrodynamic numerical modelling outputs and various theoretical parameters are used to describe the morphological characteristics of sediment waves and their spatio-temporal evolution in a hydrodynamically and morphodynamically complex region of the Irish Sea. Analysis reveals sediment waves in a range of sizes (height = 0.1 to 25.7 m, and wavelength = 17 to 983 m), occurring in water depths of 8.2 to 83 mLAT, and migrating at a rate of 1.1 to 79 m/yr. Combined with numerical modelling outputs, a strong divergence of sediment transport pathways from the previously understood predominantly southward flow in the south Irish Sea is revealed, both at offshore sand banks and independent sediment wave assemblages. This evidence supports the presence of a semi-closed circulatory hydrodynamic and sediment transport system at Arklow Bank (an open-shelf linear sand bank). Contrastingly, the Lucifer–Blackwater Bank complex and associated sediment waves are heavily influenced by the interaction between a dominant southward flow and a residual headland eddy, which also exerts a strong influence on the adjacent banner bank. Furthermore, a new sediment transfer system is defined for offshore independent sediment wave assemblages, whereby each sediment wave field is supported by circulatory residual current cells originating from offshore sand banks. These new data and results improve knowledge of seabed morphodynamics in tidally-dominated shelf seas, which has direct implications for offshore renewable developments and long-term marine spatial planning. Full article

Over the years, people’s interest in protecting the natural environment and its resources has increased significantly. In this context, natural parks have become a new tourist destination, which has grown exponentially in recent decades and developed into mass tourism. This made it necessary to realize adequate infrastructures (roads, accommodation facilities reception, etc.) to allow visitors to enjoy parks. A recent trip to China made it possible to observe how this type of tourism has developed and raised some concerns and the need to understand whether this phenomenon is also present in other countries. In particular, this research examines the infrastructures (roads, accommodation facilities, and visitor centres) of some parks in the United States and Europe to compare them with the Chinese experience. The analysis revealed a difference in the visiting facilities of European parks compared to those in China and North America. In fact, the management and fruition of European parks seem to have less impact on the territories because they make use of road networks and accommodation facilities already present in the territory and that are often present in small villages. While in the case of China and the USA, it has been necessary to build new visitor centres and accommodation facilities in territories that were often uninhabited. Full article