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Ferrero, A. M., G. Forlani, R. Roncella et H. I. Voyat. « Advanced Geostructural Survey Methods Applied to Rock Mass Characterization ». Rock Mechanics and Rock Engineering 42, no 4 (21 juin 2008) : 631–65. http://dx.doi.org/10.1007/s00603-008-0010-4.
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Ferrero, Anna Maria, Maria Migliazza, Riccardo Roncella et Elena Rabbi. « Rock slopes risk assessment based on advanced geostructural survey techniques ». Landslides 8, no 2 (2 décembre 2010) : 221–31. http://dx.doi.org/10.1007/s10346-010-0246-4.
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Migliazza, Maria, Maria Teresa Carriero, Andrea Lingua, Emanuele Pontoglio et Claudio Scavia. « Rock Mass Characterization by UAV and Close-Range Photogrammetry : A Multiscale Approach Applied along the Vallone dell’Elva Road (Italy) ». Geosciences 11, no 11 (21 octobre 2021) : 436. http://dx.doi.org/10.3390/geosciences11110436.
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Geostructural rock mass surveys and the collection of data related to discontinues provide the basis for the characterization of rock masses and the study of their stability conditions. This paper describes a multiscale approach that was carried out using both non-contact techniques and traditional support techniques to survey certain geometrical features of discontinuities, such as their orientation, spacing, and useful persistence. This information is useful in identifying the possible kinematics and stability conditions. These techniques are extremely useful in the case study of the Elva valley road (Northern Italy), in which instability phenomena are spread across 9 km in an overhanging rocky mass. A multiscale approach was applied, obtaining digital surface models (DSMs) at three different scales: large-scale DSM of the entire road, a medium-scale DSM to assess portions of the slope, and a small-scale DSM to assess single discontinuities. The georeferenced point cloud and consequent DSMs of the slopes were obtained using an unmanned aerial vehicle (UAV) and terrestrial photogrammetric technique, allowing topographic and rapid traditional geostructural surveys. This technique allowed us to take measurements along the entire road, obtaining geometrical data for the discontinuities that are statistically representative of the rock mass and useful in defining the possible kinematic mechanisms and volumes of potentially detachable blocks. The main purpose of this study was to analyse how the geostructural features of a rock mass can affect the stability slope conditions at different scales in order to identify road sectors susceptible to different potential failure mechanisms using only kinematic analysis.
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Mineo, Simone, Giovanna Pappalardo et Salvatore Onorato. « Geomechanical Characterization of a Rock Cliff Hosting a Cultural Heritage through Ground and UAV Rock Mass Surveys for Its Sustainable Fruition ». Sustainability 13, no 2 (18 janvier 2021) : 924. http://dx.doi.org/10.3390/su13020924.
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In mountainous areas around the world, dealing with rockfalls means facing some technical survey difficulties due to the low accessibility of areas and the height of slopes. If a cultural heritage is also threatened by such mass movement, the need of specific survey solutions, even in a combined asset, is required. This paper deals with the integration of ground and UAV rock mass surveys aimed at defining the rockfall attitude of an unstable rock cliff sector hosting an example of cultural heritage in tourist area of southern Italy, whose fruition has already been threatened by the occurrence of rockfalls. As an example of the defensive architecture of XII and XIII centuries, the Saracen Castle in Taormina is reached by hundreds of visitors each year, but its access path and the surrounding area are threatened by the unstable condition of the cliff, hosting unstable rock volumes on kinematically critical planes. In order to achieve a reliable geostructural setting of the cliff, aiming at its possible securing through proper mitigation works, ground rock mass surveys could not provide enough information due to the bad accessibility of the rock faces. Therefore, a survey by an Unmanned Aerial Vehicle, with a reliable verified accuracy, was carried out to map the discontinuity planes especially occurring at the highest portions of the cliff, achieving geostructural data of different fronts of the cliff. Ground and aerial data were combined and statistically analyzed to define the main kinematic failure patterns. In this perspective, a critical comparison between the two employed surveying methodologies is proposed herein, highlighting that both approaches are affected by potential and limitations and that the integration of the mutual dataset represents a suitable solution for a complete rock mass characterization in this type of areas. Furthermore, rockfall simulations allowed ascertaining that potential falling blocks would cross the access path to the castle, thus representing a natural threat to the fruition of cultural heritage, thus proving the need of mitigation measures to ensure the safe fruition of the cultural heritage.
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Cotecchia, V., P. De Bellis, P. Lollino, L. Monterisi et C. Tria. « Geostructural survey and stability analysis of the calcareous cliff of Vieste (Gargano-Southern Italy) ». Bulletin of Engineering Geology and the Environment 68, no 1 (4 novembre 2008) : 35–45. http://dx.doi.org/10.1007/s10064-008-0169-7.
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Bonetto, Sabrina, Gessica Umili, Anna Maria Ferrero, Rodolfo Carosi, Matteo Simonetti, Alessandro Biasi, Maria Rita Migliazza et Stefano Bianchini. « Geostructural and Geomechanical Study of the Piastrone Quarry (Seravezza, Italy) Supported by Photogrammetry to Assess Failure Mode ». Geosciences 10, no 2 (8 février 2020) : 64. http://dx.doi.org/10.3390/geosciences10020064.
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The use of non-contact-techniques for rock mass characterization has been growing significantly over the last decade. However, their application to stability assessment of ornamental stone has not yet received much attention from researchers. This study utilizes rock mass data both in terms of slope orientations and degree of fracturing obtained from a point cloud, a set of three-dimensional (3D) points representing a rock mass surface, to (1) investigate the influence of geostructures at different scales and (2) assess quarry stability by determining areas susceptible to different failure types. Multi-resolution point clouds are obtained through several photogrammetric survey techniques to identify important structural elements of the site. By integrating orientation data of discontinuity planes, obtained with a traditional survey, and of traces, outlined on point clouds, several joint sets were identified. Kinematic tests revealed various potential failure modes of the rock slope. Moreover, an analysis of the influence of the discontinuity strength determined by the presence of rock bridges was carried out. The study revealed that the strength of the quarry face is governed by the presence of rock bridges that act to improve the stability condition of the rock fronts.
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Daniela, Ruberti, Marino Ermanno, Pignalosa Antonio, Romano Pasquale et Vigliotti Marco. « Assessment of Tuff Sea Cliff Stability Integrating Geological Surveys and Remote Sensing. Case History from Ventotene Island (Southern Italy) ». Remote Sensing 12, no 12 (22 juin 2020) : 2006. http://dx.doi.org/10.3390/rs12122006.
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This study provides a detailed integrated analysis of the erosional processes affecting the volcanoclastic headlands of a pocket beach, of a typical Tyrrhenian volcanic island (Ventotene, south Italy). It compares the survey carried out in 2012 and the recent landslides that occurred in 2018–2020. The studied tuff cliff is characterised by steep, up to overhanging walls affected by a fracture network, which locally isolates blocks in precarious equilibrium. The stability conditions of the southern Cala Nave Bay sea cliff were evaluated by integrating a geological field survey, structural analysis of discontinuities, and a detailed topographic survey consisting of a terrestrial laser scanner (TLS) and photogrammetry data acquisition and processing, providing a three-dimensional (3D) model of the sea cliff. The 3D model of the area affected by the recent landslides was created using proximity photogrammetry, the Structure for Motion (SfM) methodology. The fracture network was represented by using high-resolution digital models and projected to realize geostructural vertical mapping of the cliff. The data acquired in 2012 were more recently compared with further surveys carried out, following rock failures that occurred in winter 2019–2020. The detachment planes and failure modalities coincide perfectly with the ones previously assessed. The applied techniques and the comparison with the recent rock failures have proven to be important in defining these conditions to address risk mitigation interventions.
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Imposa, S., M. Corrao, F. Barone, G. Coco, R. Occhipinti et P. Mozzicato. « Geostructural and geognostic survey for a stability analysis of the calcareous cliff of Ispica (Hyblean plateau, southeastern Sicily) ». Bulletin of Engineering Geology and the Environment 69, no 2 (21 janvier 2010) : 247–56. http://dx.doi.org/10.1007/s10064-009-0257-3.
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Toropetsky, K. V., G. A. Borisov, A. S. Smirnov et A. V. Nosikov. « ANALYSIS OF FRACTION CONTENTS IN ROCK SCRATCH TESTS FOR ESTIMATING THE ANGLE OF INTERNAL FRICTION FOR THE SEDIMENTARY COVER OF THE KOVYKTA FIELD ». Geodynamics & ; Tectonophysics 12, no 3S (19 octobre 2021) : 748–53. http://dx.doi.org/10.5800/gt-2021-12-3s-0551.
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The article describes the possibility of using the granulometric analysis of rock cuttings formed in controlled core scratching tests to estimate the angle of internal friction.The study object is the Kovykta gas-condensate field (GCF) that occupies a wide area in the southeastern part of the Irkutsk amphitheater of the Siberian platform. This uniquely complex geological structure holds significant reserves of hydrocarbons. Its sedimentary cover is composed of the Vendian – lower Paleozoic and partly Riphean formations. Their total thickness exceeds 6000 m, as estimated from the new seismic survey data [Vakhromeev et al., 2019].The sedimentary cover of the Kovykta GCF has been studied by surface and borehole geophysical techniques, remote sensing and geostructural methods, in combination with the tectonophysical approach [Seminsky et al., 2018] based on drilling data, including standard and special core sampling data.
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Caputo, Teresa, Angela Mormone, Ermanno Marino, Giuseppina Balassone et Monica Piochi. « Remote Sensing and Mineralogical Analyses : A First Application to the Highly Active Hydrothermal Discharge Area of Pisciarelli in the Campi Flegrei Volcanic Field (Italy) ». Remote Sensing 14, no 15 (22 juillet 2022) : 3526. http://dx.doi.org/10.3390/rs14153526.
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This paper explored the relationship between acidic sulfate alteration, geostructural frameworks, and geomorphological changes that can be observed in active volcanic hydrothermal systems. The target area was Pisciarelli in the Campi Flegrei volcano, where diffuse acidic sulfate alteration and hydrothermal dynamics have been growing since 2012, causing a progressive deterioration of landscapes. Terrestrial Laser Scanner (TLS), photogrammetry of proximity survey, geological field work, mineralogical and geochemical analysis with Optical Microscopy (OM), electron microscopy, and energy dispersive micro-analysis (BSEM-EDS) and X-ray Powder Diffraction (XRPD) to characterize (and monitor) altered rock outcrops were repeatedly carried out in the area. We present the multi-temporal acquisition and analysis referring to Terrestrial Laser Scanning (TLS) datasets (2014 survey) with 3D-point clouds obtained from the Structure for Motion (SfM) photogrammetry (2021 survey) with a high-resolution digital camera aimed at evaluating volumetric changes on the mostly damaged and altered fault scarp. For each survey, we obtained a vertical Digital Elevation Model (DEM) and a true color RGB orthomosaic that provided the setting of the area at the different times and its evolution through their comparison. Changing sites were examined in the field and characterized for mineralogical and geochemical purposes. The investigated slope lost up to about 4 m3 of deposits between 2014 and 2021, mostly related to hydrothermal alteration induced by gas emissions and meteoric infiltration. Our methodological approach appears promising to evaluate evolution and rock-fall susceptibility of solfataric terrains subjected to hydrothermal dynamics.
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Petronio, Lorenzo, Flavio Poletto et Andrea Schleifer. « Interface prediction ahead of the excavation front by the tunnel-seismic-while-drilling (TSWD) method ». GEOPHYSICS 72, no 4 (juillet 2007) : G39—G44. http://dx.doi.org/10.1190/1.2740712.
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Predicting geologic interfaces ahead of a tunnel front is of major importance when boring tunnels. Unexpected variations in ground properties can cause problems for tunnel-boring advance and risk for human safety. The tunnel-seismic-while-drilling (TSWD) method utilizes noise produced during mechanical excavation to obtain interpretable seismic data. This passive method uses accelerometers mounted on the advancing tunnel-boring machine (reference signals) together with seismic sensors located along and outside the tunnel. Data recorded by fixed sensors are crosscorrelated with the reference signal and sorted by offset. Similar to reverse vertical seismic profiling, crosscorrelated TSWD data are processed to extract the reflected wavefield. During mechanical excavation of a [Formula: see text] tunnel through upper Triassic dolomite, a survey was performed to predict geologic interfaces. Faults intersecting the tunnel were observed on seismic TSWD data and later were confirmed by geostructural inspection. P- and S-wave interval velocities obtained by TSWD data along the bored tunnel were used to compute dynamic rock moduli to support tunnel completion.
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Kohlhepp, Bernd, Robert Lehmann, Paul Seeber, Kirsten Küsel, Susan E. Trumbore et Kai U. Totsche. « Aquifer configuration and geostructural links control the groundwater quality in thin-bedded carbonate–siliciclastic alternations of the Hainich CZE, central Germany ». Hydrology and Earth System Sciences 21, no 12 (1 décembre 2017) : 6091–116. http://dx.doi.org/10.5194/hess-21-6091-2017.
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Abstract. The quality of near-surface groundwater reservoirs is controlled, but also threatened, by manifold surface–subsurface interactions. Vulnerability studies typically evaluate the variable interplay of surface factors (land management, infiltration patterns) and subsurface factors (hydrostratigraphy, flow properties) in a thorough way, but disregard the resulting groundwater quality. Conversely, hydrogeochemical case studies that address the chemical evolution of groundwater often lack a comprehensive analysis of the structural buildup. In this study, we aim to reconstruct the actual spatial groundwater quality pattern from a synoptic analysis of the hydrostratigraphy, lithostratigraphy, pedology and land use in the Hainich Critical Zone Exploratory (Hainich CZE). This CZE represents a widely distributed yet scarcely described setting of thin-bedded mixed carbonate–siliciclastic strata in hillslope terrains. At the eastern Hainich low-mountain hillslope, bedrock is mainly formed by alternated marine sedimentary rocks of the Upper Muschelkalk (Middle Triassic) that partly host productive groundwater resources. Spatial patterns of the groundwater quality of a 5.4 km long well transect are derived by principal component analysis and hierarchical cluster analysis. Aquifer stratigraphy and geostructural links were deduced from lithological drill core analysis, mineralogical analysis, geophysical borehole logs and mapping data. Maps of preferential recharge zones and recharge potential were deduced from digital (soil) mapping, soil survey data and field measurements of soil hydraulic conductivities (Ks). By attributing spatially variable surface and subsurface conditions, we were able to reconstruct groundwater quality clusters that reflect the type of land management in their preferential recharge areas, aquifer hydraulic conditions and cross-formational exchange via caprock sinkholes or ascending flow. Generally, the aquifer configuration (spatial arrangement of strata, valley incision/outcrops) and related geostructural links (enhanced recharge areas, karst phenomena) control the role of surface factors (input quality and locations) vs. subsurface factors (water–rock interaction, cross-formational flow) for groundwater quality in the multi-layered aquifer system. Our investigation reveals general properties of alternating sequences in hillslope terrains that are prone to forming multi-layered aquifer systems. This synoptic analysis is fundamental and indispensable for a mechanistic understanding of ecological functioning, sustainable resource management and protection.
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Martino, S., et P. Mazzanti. « Integrating geomechanical surveys and remote sensing for sea cliff slope stability analysis : the Mt. Pucci case study (Italy) ». Natural Hazards and Earth System Sciences 14, no 4 (11 avril 2014) : 831–48. http://dx.doi.org/10.5194/nhess-14-831-2014.
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Abstract. An integrated approach to the geomechanical characterization of coastal sea cliffs was applied at Mt. Pucci (Gargano promontory, Southern Italy) by performing field-based geomechanical investigations and remote geostructural investigations via a terrestrial laser scanner (TLS). The consistency of the integrated techniques allowed to achieve a comprehensive and affordable characterization of the main joint sets on the sea cliff slope. The observed joint sets were considered to evaluate the proneness of the slope to rock failures by attributing safety factor (SF) values to the topple- and wedge-prone rock blocks under three combined or independent triggering conditions: (a) hydrostatic water pressures within the joints, (b) seismic action, and (c) strength reduction due to weathering of the joint surfaces. The combined action of weathering and water pressures within the joints was also considered, resulting in a significant decrease in the stability. Furthermore, remote survey analyses via InfraRed Thermography (IRT) and Ground Based Synthetic Aperture Radar Interferometry (GBInSAR) were performed to evaluate the role of the surveyed joint sets in inducing instabilities in the Mt. Pucci sea cliff. The results from the remote surveys: (i) GBInSAR monitoring revealed permanent displacements coupled to cyclic daily displacements, these last ones detected in certain sectors of the cliff wall; (ii) the thermal images allowed us to identify anomalies that correspond well to the main joints and to the slope material released due to recent collapses.
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Pontoglio, E., E. Colucci, A. Lingua, P. Maschio, M. R. Migliazza et C. Scavia. « UAV AND CLOSE-RANGE PHOTOGRAMMETRY TO SUPPORT GEO-MECHANICAL ANALYSIS IN SAFETY ROAD MANAGEMENT : THE “VALLONE D’ELVA” ROAD ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B2-2020 (14 août 2020) : 1159–66. http://dx.doi.org/10.5194/isprs-archives-xliii-b2-2020-1159-2020.
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Abstract. In the last decades, the development of geomatics and geomechanics techniques integration in the environmental field permits to obtain more detailed and accurate results, reducing the survey costs. The aim of the present work was aimed to apply these innovative combined methods and techniques in order to gain a detailed analysis of landslide hazard and on the stability condition of rocky slopes, to get useful information for subsequent design and feasibility planning of Vallone d’Elva road. During two different surveys period, geostructural surveys were carried out in situ (i.e. spatial orientation of discontinuity planes, their spacing and persistence), associated with geomatics surveys using drones (UAV technique – Unmanned Aerial Vehicle) and terrestrial photogrammetric technique to get high-resolution images of the rockwalls along the road in areas with complex orography and inaccessible. Their data processing has allowed the generation of different kind of data at different scales, like some 3D dense point clouds with a huge definition, which have been used to generate three-dimensional surfaces models. This procedure has allowed obtaining DSM (Digital Surface Model), DTMs (Digital Terrain Models) and orthophotos with centimetre resolution (mean 4 cm). Moreover, to identify the geomechanical rockmasses features, have been computed a new photogrammetric product on 16 specific rockwall sites along the road: “vertical orthophotos”, with details of few mm. Besides, over then twenty detailed DTMs of rockwalls along the entire road have been generated to measure plane orientation, spacing and other geometrical characteristics of outcropping rock masses, which have been statistically collected and analysed.
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Santise, M., K. Thoeni, R. Roncella, F. Diotri et A. Giacomini. « ANALYSIS OF LOW-LIGHT AND NIGHT-TIME STEREO-PAIR IMAGES FOR PHOTOGRAMMETRIC RECONSTRUCTION ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2 (30 mai 2018) : 1015–22. http://dx.doi.org/10.5194/isprs-archives-xlii-2-1015-2018.
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Rockfalls and rockslides represent a significant risk to human lives and infrastructures because of the high levels of energy involved in the phenomena. Generally, these events occur in accordance to specific environmental conditions, such as temperature variations between day and night, that can contribute to the triggering of structural instabilities in the rock-wall and the detachment of blocks and debris. The monitoring and the geostructural characterization of the wall are required for reducing the potential hazard and to improve the management of the risk at the bottom of the slopes affected by such phenomena. In this context, close range photogrammetry is largely used for the monitoring of high-mountain terrains and rock walls in mine sites allowing for periodic survey of rockfalls and wall movements. This work focuses on the analysis of low-light and night-time images of a fixed-base stereo pair photogrammetry system. The aim is to study the reliability of the images acquired over the night to produce digital surface models (DSMs) for change detection. The images are captured by a high-sensitivity DLSR camera using various settings accounting for different values of ISO, aperture and time of exposure. For each acquisition, the DSM is compared to a photogrammetric reference model produced by images captured in optimal illumination conditions. Results show that, with high level of ISO and maintaining the same grade of aperture, extending the exposure time improves the quality of the point clouds in terms of completeness and accuracy of the photogrammetric models.
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Umili, Gessica, Sabrina Maria Rita Bonetto, Pietro Mosca, Federico Vagnon et Anna Maria Ferrero. « In Situ Block Size Distribution Aimed at the Choice of the Design Block for Rockfall Barriers Design : A Case Study along Gardesana Road ». Geosciences 10, no 6 (7 juin 2020) : 223. http://dx.doi.org/10.3390/geosciences10060223.
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When studying rockfall phenomena, a single value of the block volume is not sufficient to take into account the natural variability of the geometrical features (orientation, spacing, persistence) of the discontinuity sets. Different approaches for obtaining cumulative distributions of potentially detachable block volumes are compared. A highly fractured rock mass outcropping along the western Lake Garda (Italy), consisting of prevailing limestone and interbedded marls, is studied in detail from geological and geostructural points of view. Then, a representative rock face has been selected and analyzed with traditional and non-contact survey methods to identify the main discontinuity sets and to collect spacing samples. Based on these data, in situ block size distributions for different combinations of sets are built following statistically-based approaches, without the use of a Discrete Fracture Network (DFN) generator. The validation of the obtained distributions is attempted based on the detached block surveyed at the foot of the slope. However, in this particular case study, the detached blocks cover only a minimal volume range compared to both theoretical values and visible rockfall scars. The fallen rock blocks have a marginal role in design block determination, since their volume depends on geological discontinuities (bedding and fractures) and could be affected by other processes after the detachment (e.g., fragmentation). The procedure here described should be standard practice in the study of rockfall events, and it should be uniform in European standards such as Eurocodes. Future developments should involve the scientific community for setting the percentiles of the probability distribution to be considered for block design definition.
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Bahrii, I. D., V. G. Semeniuk, A. A. Loktiev, V. S. Loktiev, N. S. Dovbysh et S. M. Dovbysh. « Study of mapping features of preconditions for formation of hydrocarbon deposits on the continental slope of the Western Black Sea basin ». Мінеральні ресурси України, no 1 (15 avril 2021) : 39–45. http://dx.doi.org/10.31996/mru.2021.1.39-45.
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The integral thermo-atmogeochemical structural investigations (TAGSI) have been carried out at the continental slope of the Western Black Sea Depression for the first time. The technique of TAGSI as non-traditional and cost-effective exploration technology is originally developed at Institute of Geological Sciences. It consists of phased geo-structural researches and analysis of fault tectonics, morphological analysis and neotectonic interpretation of space images, thermal and atmo-geochemical surveying, lab measurements and processing of the data acquired to build thematic map using GIS technologies. Field data acquisition stage includes thermometric, emanation and gas surveying (Rn/Tn, He, CO2, H2, free hydrocarbons) in petroleum-prone onshore areas and bottom sediments (up to 2 m below the surface) thermometry, Rn-metering and measurements of gas content in the near-bottom layer offshore.To conduct the surveying there was developed a special instrument with some modifications designed to work onshore and offshore respectively. This technology is tested in different regions of Ukraine over known oil and gas fields. The results of TAGSI are considered in the paper. The geostructural analysis, interpretation of space images, atmogeochemical survey of the near-bottom water layer (radon, helium, carbon dioxide, hydrogen, free hydrocarbons), thermic and lithogeochemical examination of bottom sediments enable to outline the petroleum-promising areas. Morphological, structural, tectonic, stratigraphic features of the continental slope’s structure are characterized. It has been found that potential petroleum-bearing structures occur in the region, which are genetically similar to the productive Mesozoic and Cenozoic stratons of the northwestern shelf and other areas of the Crimean – Caucasian Region. The results of the carried out studies show that it is purposeful to use TAGSI for local forecast of promising targets at the early search stages, for rational location of drillholes, prospecting and recovery of hydrocarbons.
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Casagrande, G., F. Cucchi et L. Zini. « Hazard connected to railway tunnel construction in karstic area : applied geomorphological and hydrogeological surveys ». Natural Hazards and Earth System Sciences 5, no 2 (23 février 2005) : 243–50. http://dx.doi.org/10.5194/nhess-5-243-2005.
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Abstract. In a mature karstic system, the realisation of galleries using the methodology of railway tunnel boring machine (TBM) involves particular problems due to the high risk of interference with groundwater (often subject to remarkable level variations) and with cavities and/or thick fill deposits. In order to define groundwater features it is necessary to investigate both hydrodynamic and karstification. To define and quantify the karst phenomenon in the epikarst of the Trieste Karst (Italy), an applied geomorphological approach has been experimented with surface and cavity surveys. The surface surveys have contributed to determining the potential karst versus the different outcropping lithologies and to define the structural setting of the rocky mass also through the realisation of geostructural stations and the survey of the main lines thanks to photo-interpretation. Moreover, all the dolines and the cavities present in the area interested by the gallery have been studied by analysing the probable extension of caves and/or of the secondary fill deposits and by evaluating the different genetic models. In an area 900m large and 27km long, which has been studied because of the underground karst, there are 41 dolines having diameters superior to 100m and 93 dolines whose diameters range between 100 and 50m; the dolines whose diameters are inferior to 50m are 282. The entrances of known and registered cavities in the cadastre records are 520. The hypogeal surveys have shown 5 typologies in which it has been possible to group all the cavities present in a hypothetical intersection with the excavation. The comparison between surface and hypogeal structural data and the direction of development of cavities has allowed for the definition of highly karstified discontinuity families, thus having a higher risk. The comparison of the collected data has enabled to identify the lithologies and areas having major risk and thus to quantify the probability of intersection with the different cavity typologies for each area. To make an example, out of 27000m of studied gallery 3930 are the metres expected to be at very high "karst risk". Out of these, as a whole 310 are risky because of the probable presence of gallery cavities, 2170 because of the probable presence of pits and sinkholes diffusely present under the dolines, and along 1450m karst is particularly intense. Moreover, 2200 should be the metres in which the rocky mass will be particularly divided because of tectonic causes. From a hydrogeological point of view a monitoring of water level has started to quantify water excursion, due to closeness of the railway tunnel to the mean water level. First results related to galleries intersection are here presented.
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Martino, S., et P. Mazzanti. « Analysis of sea cliff slope stability integrating traditional geomechanical surveys and remote sensing ». Natural Hazards and Earth System Sciences Discussions 1, no 4 (31 juillet 2013) : 3689–734. http://dx.doi.org/10.5194/nhessd-1-3689-2013.
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Abstract. An integrated approach to the geomechanical characterization of coastal sea cliffs was demonstrated at Mt. Pucci (Gargano promontory, Southern Italy) by performing direct traditional geomechanical and remote geostructural investigations via Terrestrial Laser Scanner (TLS). The consistency of the integrated techniques allowed us to achieve a comprehensive and affordable characterization of the main joint sets on the sea cliff slope. The observed joint sets were observed to evaluate the susceptibility of the slope to rock falls by attributing safety factors (SFs) to the topple- and wedge-prone rock blocks under three triggering conditions: (a) filling with static water, (b) seismic action, and (c) weathering of joint surfaces. The results of the susceptibility analysis for the topple-prone blocks show that the critical height of water filling of the joint is up to 50 cm and that the critical pseudo-static acceleration values vary in the range of 0.16–0.3 g depending on the block geometry and slope face orientation. For the wedge blocks, the critical height of water filling of the joint is generally up to several centimeters, and the critical pseudo-static acceleration values vary in the range of 0.05–0.8 g depending on the block geometry and slope face orientation. Moreover, the unstable conditions of the blocks due to weathering generally represent 60% of the joint degradation of the intact rock. The combined action of weathering and static water fill was also considered, resulting in a significant decrease of the SFs. Specifically, unstable conditions are associated with water levels lower than 47% of the water levels observed in intact joints, even if less than 60% of the weathering is attributed to the joints. Furthermore, remote survey analyses via Thermal InfraRed Camera and Terrestrial SAR Interferometry (TInSAR) were performed to evaluate the role of the surveyed joint sets in inducing instabilities in the Mt. Pucci sea cliff. The results of this study can be summarized as follows: (i) the thermal images allowed us to identify anomalies that correspond well to the main joints and to the slope material released due to recent collapses; and (ii) TInSAR monitoring revealed permanent displacements greater than 1 mm, and cyclic daily displacements of up to 1.2 mm were detected in certain sectors and were attributed to thermal variation of the rock mass.
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Alekseev, Viktor. « Deep structure and geodynamic conditions of granitoid magmatism in the Eastern Russia ». Journal of Mining Institute 243 (14 juin 2020) : 259. http://dx.doi.org/10.31897/pmi.2020.3.259.
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We investigated the deep structure of the lithosphere and the geodynamic conditions of granitoid magmatism in the Eastern Russia within the borders of the Far Eastern Federal District. The relevance of the work is determined by the need to establish the geotectonic and geodynamic conditions of the granitoids petrogenesis and ore genesis in the Russian sector of the Pacific Ore Belt. The purpose of the article is to study the deep structure of the lithosphere and determine the geodynamic conditions of granitoid magmatism in the East of Russia. The author's data on the magmatism of ore regions, regional granitoids correlations, archive and published State Geological Map data, survey mapping, deep seismic sounding of the earth's crust, gravimetric survey, geothermal exploration, and other geophysical data obtained along geotraverses. The magma-controlling concentric geostructures of the region are distinguished and their deep structure is studied. The connection of plume magmatism with deep structures is traced. The chain of concentric geostructures of Eastern Russia controls the trans-regional zone of leucocratization of the earth's crust with a width of more than 1000 km, which includes the Far Eastern zone of Li-F granites. Magmacontrolling concentric geostructures are concentrated in three granitoid provinces: Novosibirsk-Chukotka, Yano-Kolyma, and Sikhote-Alin. The driving force of geodynamic processes and granitoid magmatism was mantle heat fluxes in the reduced zones of the lithospheric slab. The distribution of slab windows along the Pacific mobile belt's strike determines the location of concentric geostructures and the magnitude of granitoid magmatism in the regional provinces. Mantle diapirs are the cores of granitoid ore-magmatic systems. The location of the most important ore regions of the Eastern Russia in concentric geostructures surrounded by annuli of negative gravity anomalies is the most important regional metallogenic pattern reflecting the correlation between ore content and deep structure of the earth's crust.
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Loiotine, Lidia, Gioacchino Francesco Andriani, Michel Jaboyedoff, Mario Parise et Marc-Henri Derron. « Comparison of Remote Sensing Techniques for Geostructural Analysis and Cliff Monitoring in Coastal Areas of High Tourist Attraction : The Case Study of Polignano a Mare (Southern Italy) ». Remote Sensing 13, no 24 (12 décembre 2021) : 5045. http://dx.doi.org/10.3390/rs13245045.
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Rock slope failures in urban areas may represent a serious hazard for human life, as well as private and public property, even on the occasion of sporadic episodes. Prevention and mitigation measures indispensably require a proper rock mass characterization, which is often achieved by means of time-consuming, costly and dangerous field surveys. In the last decades, remote sensing devices such as high-resolution digital cameras, laser scanners and drones have been widely used as supplementary techniques for rock slope analysis and monitoring, especially in poorly accessible areas, or in sites of large extension. Although several methods for rock mass characterization by means of remote sensing techniques have been reported in specific studies, there are very few contributions that focused on comparing the different methods in an attempt to establish their advantages and limitations. With this study, we performed digital photogrammetry, Terrestrial Laser Scanning and Unmanned Aerial Vehicle surveys on a cliff located in a popular tourist attraction site, characterized by complex geological and geomorphological settings, as well as by disturbance elements such as vegetation and human activities. For each point cloud, we applied geostructural analysis by means of semi-automatic methods, and then compared multi-temporal acquisitions for cliff monitoring. By quantitative comparison of the results and validation by means of conventional geostructural field surveys, the pros and cons of each method were outlined in attempt to depict the conditions and goals the different techniques seem to be more suitable for.
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De Vita, P., A. Cevasco et C. Cavallo. « Detailed rock failure susceptibility mapping in steep rocky coasts by means of non-contact geostructural surveys : the case study of the Tigullio Gulf (Eastern Liguria, Northern Italy) ». Natural Hazards and Earth System Sciences 12, no 4 (10 avril 2012) : 867–80. http://dx.doi.org/10.5194/nhess-12-867-2012.
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Abstract. In this study, an engineering geological analysis for the assessment of the rock failure susceptibility of a high, steep, rocky coast was developed by means of non-contact geostructural surveys. The methodology was applied to a 6-km coastal cliff located in the Gulf of Tigullio (Northern Tyrrhenian Sea) between Rapallo and Chiavari. The method is based on the geostructural characterisation of outcropping rock masses through meso- and macroscale stereoscopic analyses of digital photos that were taken continuously from a known distance from the coastline. The results of the method were verified through direct surveys of accessible sample areas. The rock failure susceptibility of the coastal sector was assessed by analysing the fundamental rock slope mechanisms of instability and the results were implemented into a Geographic Information System (GIS). The proposed method is useful for rock failure susceptibility assessments in high, steep, rocky coastal areas, where accessibility is limited due to cliffs or steep slopes. Moreover, the method can be applied to private properties or any other area where a complete and systematic analysis of rock mass structural features cannot be achieved. Compared to direct surveys and to other non-contact methods based on digital terrestrial photogrammetry, the proposed procedure provided good quality data of the structural features of the rock mass at a low cost. Therefore, the method could be applied to similar coastal areas with a high risk of rock failure occurrence.
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Walker, Christopher, Ana Heitor et Barry Clarke. « Influence of Weather-Driven Processes on the Performance of UK Transport Infrastructure with Reference to Historic Geostructures ». Applied Sciences 12, no 15 (25 juillet 2022) : 7461. http://dx.doi.org/10.3390/app12157461.
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Several factors control the vulnerability of historic geostructures to climate change. These factors are both temporally and spatially variable depending on construction techniques and climatic conditions. This paper provides a review of both the historical construction practices on the UK transport network and recent developments in the understanding of climate change effects, allowing for an assessment of the impact of climate change on existing geostructures. Geostructures in the UK can be split between pre-regulation and post-regulation construction techniques. In general, highways were constructed after the implementation of modern regulations and are therefore less vulnerable to climate change due to formalisation of construction methods. In comparison, the performance of the railway network has shown to be inferior due to historic construction practices including poor or absent compaction, lack of consideration for foundations, or selection of fill materials. Recent findings have shown that the impacts of climate change are also a multiscale problem, influenced not only by regional geology but also the pore structure of soils and its evolution. While the research into these impacts is critical, the limitations of common methods employed to survey these structures and study the behaviour of their constituent materials requires consideration. In this paper, these aspects are examined in detail in a bid to integrate holistically the complexity of the systems involved.
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Azimov, O., I. Bagriy et V. Dubosarsky. « PREDICTING HYDROCARBON FIELDS USING THE COMPLEX OF ATMOGEOCHEMICAL AND REMOTE SENSING METHODS ». Visnyk of Taras Shevchenko National University of Kyiv. Geology, no 3(98) (2022) : 104–9. http://dx.doi.org/10.17721/1728-2713.98.13.
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Using the technology of structural, thermic, and atmogeochemical investigations a number of the studies within the Piatyhorivka area of the DnieperDonets Depression were performed. Among the studies there were the geostructural and morphostructural analyses, the structural interpretation of satellite data, field works on the emanation and thermometric surveys, laboratory chromatographic analyses of gas samples collected from the undersoil layer, integrated interpretation of atmogeochemical and remote sensing data, predicting oil-gas occurrence for the Piatyhorivka area. It is found that this area is located in the complicated structural and tectonic environment. Within its boundaries the relative "autonomic" northern and southern zones of the anomalous gas elimination are detected and five local plots of the difficult configuration in a plane projected for the further exploration of oil and gas deposits are identified.
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Ferrero, A. M., M. Migliazza, R. Roncella et A. Segalini. « Rock cliffs hazard analysis based on remote geostructural surveys : The Campione del Garda case study (Lake Garda, Northern Italy) ». Geomorphology 125, no 4 (février 2011) : 457–71. http://dx.doi.org/10.1016/j.geomorph.2010.10.009.
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Coli, N., G. Pranzini, A. Alfi et V. Boerio. « Evaluation of rock-mass permeability tensor and prediction of tunnel inflows by means of geostructural surveys and finite element seepage analysis ». Engineering Geology 101, no 3-4 (octobre 2008) : 174–84. http://dx.doi.org/10.1016/j.enggeo.2008.05.002.
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Mineo, S., G. Pappalardo, F. Rapisarda, A. Cubito et G. Di Maria. « Integrated geostructural, seismic and infrared thermography surveys for the study of an unstable rock slope in the Peloritani Chain (NE Sicily) ». Engineering Geology 195 (septembre 2015) : 225–35. http://dx.doi.org/10.1016/j.enggeo.2015.06.010.
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Cigna, F., C. Del Ventisette, G. Gigli, F. Menna, F. Agili, V. Liguori et N. Casagli. « Ground instability in the old town of Agrigento (Italy) depicted by on-site investigations and Persistent Scatterers data ». Natural Hazards and Earth System Sciences 12, no 12 (6 décembre 2012) : 3589–603. http://dx.doi.org/10.5194/nhess-12-3589-2012.
Texte intégralRésumé :
Abstract. We combine on-site investigations with the interpretation of satellite Persistent Scatterers (PS) to analyse ground instability in the historic town of Agrigento, Italy. Geological and geomorphologic surveys, together with geostructural and kinematic analyses, depict the deformational patterns of the northwestern sector of the town, previously documented by extensive literature available for the neighbouring Valley of the Temples. The geological and geomorphologic maps are reconstructed by combining bibliographic studies, field surveys and aerial stereo-interpretation. ERS-1/2 PS data reveal deformation velocities up to 18–20 mm yr−1 in 1992–2000 over the Addolorata landslide, and a sudden motion of 1.6 cm over the Bishop's Seminary in 1999. RADARSAT-1 PS data highlight velocities of 3.0 mm yr−1 for St. Gerlando's Cathedral and reveals worsening of its structural instability since 2006. Ground instability of the town is controlled by low quality and high fracturing of the Agrigento formation rock masses, and the remarkable contrast between different mechanical behaviours of its calcarenite (brittle), silt and clay (plastic) facies. Slow landslides and widespread erosion are also recognised in the clays of the underlying Monte Narbone formation. Coexistence of these factors induces progressive retrogression of the edge of the Girgenti hill and damages the overlying historic buildings, whose stability and safe accessibility are nowadays almost compromised.
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Cigna, F., C. Del Ventisette, V. Liguori et N. Casagli. « Advanced radar-interpretation of InSAR time series for mapping and characterization of geological processes ». Natural Hazards and Earth System Sciences 11, no 3 (16 mars 2011) : 865–81. http://dx.doi.org/10.5194/nhess-11-865-2011.
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Abstract. We present a new post-processing methodology for the analysis of InSAR (Synthetic Aperture Radar Interferometry) multi-temporal measures, based on the temporal under-sampling of displacement time series, the identification of potential changes occurring during the monitoring period and, eventually, the classification of different deformation behaviours. The potentials of this approach for the analysis of geological processes were tested on the case study of Naro (Italy), specifically selected due to its geological setting and related ground instability of unknown causes that occurred in February 2005. The time series analysis of past (ERS1/2 descending data; 1992–2000) and current (RADARSAT-1 ascending data; 2003–2007) ground movements highlighted significant displacement rates (up to 6 mm yr−1) in 2003–2007, followed by a post-event stabilization. The deformational behaviours of instable areas involved in the 2005 event were also detected, clarifying typology and kinematics of ground instability. The urban sectors affected and unaffected by the event were finally mapped, consequently re-defining and enlarging the influenced area previously detected by field observations. Through the integration of InSAR data and conventional field surveys (i.e. geological, geomorphologic and geostructural campaigns), the causes of instability were finally attributed to tectonics.
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Alicandro, M., E. Candigliota, D. Dominici, F. Immordino, R. Quaresima et S. Zollini. « ALBA FUCENS ARCHAEOLOGICAL SITE : MULTISCALE AND MULTIDISCIPLINARY APPROACH FOR RISK ASSESSMENT AND CONSERVATION ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W11 (4 mai 2019) : 47–53. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w11-47-2019.
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<p><strong>Abstract.</strong> The Latin Colony (303 BC) of Alba Fucens (L’Aquila, Italy) is the largest archaeological area of the whole Apennines. Due to its extension, location and environmental context, the conservation of the site is particularly complex.</p><p>For these reasons, in the paper a multiscale and multidisciplinary geoarchaeological study (remote sensing and UAV photogrammetry) of the site, to extract and measure morphostructural information to be associated to the environmental context, risk assessment and conservation, is reported.</p><p>The study area is located on a higher geostructure with a subangular shape, which suggests a tectonic origin, with respect to the surrounding plain and bounded to the East by a large fan that takes place towards the Piana del Fucino.</p><p>First, the geo-structural analysis, using the Landsat-8 and GeoEye multispectral sensors, was performed. The GeoEye satellite image allowed carrying out the morphological analysis of the archaeological area, its physical characteristics, the drainage pattern and the land use. Subsequently, after image processing of satellite data, a UAV survey was carried out in some relevant zones. Considering the UAV photogrammetry accuracy information, it was possible to extract data as map producing with several advantages (economic and time saving, minimum field work). With a multiscale and metric approach, the geomatics techniques allowed to deeply investigate some areas, creating detailed 3D models for evaluate risks and the decay. Finally, a general discussion about risk mitigation and conservation is reported.</p>
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Loiotine, Lidia, Charlotte Wolff, Emmanuel Wyser, Gioacchino Francesco Andriani, Marc-Henri Derron, Michel Jaboyedoff et Mario Parise. « QDC-2D : A Semi-Automatic Tool for 2D Analysis of Discontinuities for Rock Mass Characterization ». Remote Sensing 13, no 24 (14 décembre 2021) : 5086. http://dx.doi.org/10.3390/rs13245086.
Texte intégralRésumé :
Quantitative characterization of discontinuities is fundamental to define the mechanical behavior of discontinuous rock masses. Several techniques for the semi-automatic and automatic extraction of discontinuities and their properties from raw or processed point clouds have been introduced in the literature to overcome the limits of conventional field surveys and improve data accuracy. However, most of these techniques do not allow characterizing flat or subvertical outcrops because planar surfaces are difficult to detect within point clouds in these circumstances, with the drawback of undersampling the data and providing inappropriate results. In this case, 2D analysis on the fracture traces are more appropriate. Nevertheless, to our knowledge, few methods to perform quantitative analyses on discontinuities from orthorectified photos are publicly available and do not provide a complete characterization. We implemented scanline and window sampling methods in a digital environment to characterize rock masses affected by discontinuities perpendicular to the bedding from trace maps, thus exploiting the potentiality of remote sensing techniques for subvertical and low-relief outcrops. The routine, named QDC-2D (Quantitative Discontinuity Characterization, 2D) was compiled in MATLAB by testing a synthetic dataset and a real case study, from which a high-resolution orthophoto was obtained by means of Structure from Motion technique. Starting from a trace map, the routine semi-automatically classifies the discontinuity sets and calculates their mean spacing, frequency, trace length, and persistence. The fracture network is characterized by means of trace length, intensity, and density estimators. The block volume and shape are also estimated by adding information on the third dimension. The results of the 2D analysis agree with the input used to produce the synthetic dataset and with the data collected in the field by means of conventional geostructural and geomechanical techniques, ensuring the procedure’s reliability. The outcomes of the analysis were implemented in a Discrete Fracture Network model to evaluate their applicability for geomechanical modeling.
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Gama, Maria Filipa Perez da, Marco Antonio Braga, Marcelo Roberto Barbosa, Rafael Guimarães de Paula, Daniele Freitas Gonçalves et Iuri Viana Brandi. « GEOPHYSICS APPLIED TO THE MAPPING OF NATURAL CAVES HOSTED IN IRON ORE IN CARAJÁS (PA), BRAZIL ». Brazilian Journal of Geophysics 37, no 3 (7 octobre 2019) : 249. http://dx.doi.org/10.22564/rbgf.v37i3.2005.
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ABSTRACT. The Brazilian environmental licensing for mining activities requires technical-scientific studies to demonstrate that natural caves will be protected from the impact of the mining operations. This study presents the results of near-surface geophysical methods applied to geostructural mapping of the rock mass in which the caves are hosted. The ferruginous karstic terrains are challenging to the geophysical interpretation due to the caves’ modest dimensions and the large variations in the host rock physical properties. Electrical Resistivity and GPR (Ground Penetrating Radar) geophysical surveys, were performed overlaying a natural cave located in the surroundings of the N4EN iron mine, in the Carajás Province, northern Brazil. The resistivity data were useful to discriminate different lithotypes as well as the presence of humidity in the rock mass, while the GPR data revealed a detailed degree of fracturing of the rock mass. The presence of humidity and the highly fractured zones may constitute zones of greater fragility of the cave walls and ceiling.Keywords: speleology, GPR, electrical resistivity, near-surface geophysics.RESUMO. O licenciamento ambiental brasileiro para atividades de mineração requer que estudos técnico-científicos demonstrem que as cavernas serão protegidas do impacto das operações de mineração. Este artigo apresenta os resultados de métodos geofísicos rasos aplicados ao mapeamento geoestrutural do maciço rochoso em que as cavernas estão hospedadas. Os terrenos cársticos ferruginosos são desafiadores para a interpretação geofísica, devido às modestas dimensões das cavernas e às grandes variações nas propriedades físicas da rocha hospedeira. Levantamentos geofísicos de Resistividade Elétrica e GPR (Radar de Penetração no Solo) foram realizados sobre a uma caverna localizada no entorno da mina de ferro N4EN, na Província de Carajás, região Norte do Brasil. Os dados de resistividade foram úteis para discriminar diferentes litotipos, bem como a presença de umidade na massa rochosa, enquanto os dados de GPR revelaram em grau detalhado o fraturamento da massa rochosa. A presença de umidade e as zonas altamente fraturadas podem constituir zonas de maior fragilidade das paredes e teto da caverna.Palavras-chave: espeleologia, GPR, resistividade elétrica, geofísica rasa.
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Movchan, Igor, Zilya Shaygallyamova et Alexandra Yakovleva. « Identification of structural control factors of primary gold ore occurrences by method of unmanned aeromagnetic survey by the example of the Neryungrisky district of Yakutia ». Записки Горного института Online first (5 juillet 2022). http://dx.doi.org/10.31897/pmi.2022.23.
Texte intégralRésumé :
The long-term development of the geophysical industry, in which the methods of magnetometry are in maximum demand, as the simplest in instrumental and methodological execution, has determined the development of remote measurement methods implemented both from space and airborne carriers. The necessity to use the latter as an obligatory component of field surveys, providing coverage of significant areas, determines the need for using the unmanned low-tonnage carriers. Their use is implemented to search for predictive elements of structural (spatial, genetic) control of endogenous gold ore occurrences that allow predictive constructions, i.e., solving the problem of increasing gold reserves, which is being performed within the framework of federal programs. The purpose of the survey is to develop a system of instrumental and subsequent interpretation approaches in the organization of unmanned magnetometer survey, implemented for structural and geological mapping by the example of the Neryungrinsky district of Yakutia. Within the framework of the digital model formation of the relief and the anomalous magnetic field, a survey method using an unmanned aircraft, its technical characteristics are considered; the analysis and the author's modification of the office analysis of magnetometry data are performed. Based on the obtained materials, a physical and geological model of the investigated area was created, which is presented in the form of a geological and structural cut, accompanied by the physical characteristics of the structural and material complexes. The refinement of the physical and geological model was implemented by a joint morphostructural analysis of the remote base and the anomalous magnetic field using the results of quantative interpretation of the anomalous magnetic field. The result of the study is presented by an updated geological basis with the allocation of promising ore sites for their detailing as part of the planned large-scale geological and geophysical surveys. The scientific novelty of the work consists in the synthesis of the tried and tested methods of unmanned aeromagnetometric measurements and geostructural reconstructions, which allow the processing of both potential and non-potential geofields.
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Andriani, Gioacchino Francesco, et Lidia Loiotine. « Multidisciplinary approach for assessment of the factors affecting geohazard in karst valley : the case study of Gravina di Petruscio (Apulia, South Italy) ». Environmental Earth Sciences 79, no 19 (25 septembre 2020). http://dx.doi.org/10.1007/s12665-020-09212-y.
Texte intégralRésumé :
Abstract Management plans, actions and strategies for preventing and mitigating natural disasters require detailed information on natural and human-induced geohazards for the area under evaluation. Karst areas are particularly prone to instability due to the natural fragility of their environment but are also vulnerable due to human activity. In-depth studies of the factors controlling mass movement processes, including land use over time, become crucial for understanding instability mechanisms and future landscape evolution, as well as for designing preventive measures and control techniques. The Murge area, in the central part of Apulia (South Italy), is crossed by a vast network of dry valleys, locally named lame and gravine, whose morphology may resemble the most well-known canyons and gorges of the world. The genesis of these dry valleys is controversial and still the subject of continued debate, although their origin is directly related to the geostructural setting and the uplift of the Apulia foreland since the middle Pleistocene. Each of these karst valleys has particular morphometric characteristics as well as their own morpho-evolutionary history strongly linked to the different types of fault or fracture on which they developed. Also, geological and geotechnical characteristics of the rock substrate channel, and historic human-made slope excavation or remodeling play an important role. Unfortunately, several tragic events which occurred during the last decades have shown the susceptibility of the Apulian dry valleys to natural hazards, sometimes caused by human activities. This paper proposes, by means of a case study on a dry valley called Gravina di Petruscio in the Arco Ionico Tarantino subregion, a multidisciplinary approach using traditional methods of investigation and combining results to arrive at a critical appraisal of information that are suitable for a geohazard susceptibility analysis in karst environments. Geological, geostructural and geomechanical surveys, together with petrographic observations in thin sections of the outcropping materials, allow to understand the genesis of the valley and then its evolution mainly due to slope retreat processes. Both sides of the valley have been found to be affected by planar slides, wedge slides, direct toppling and falls, while the caves, mostly modified by humans, are affected by thinning, spalling and crushing of pillars, and partial or total collapse of cave roofs. The predisposing and triggering factors of the most common mass movements are presented and discussed. Mitigation and prevention measures for future planning, and remedial engineering structures are reported.
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Saroli, Michele, Matteo Albano, Marco Moro, Emanuela Falcucci, Stefano Gori, Fabrizio Galadini et Marco Petitta. « Looking Into the Entanglement Between Karst Landforms and Fault Activity in Carbonate Ridges : The Fibreno Fault System (Central Italy) ». Frontiers in Earth Science 10 (25 avril 2022). http://dx.doi.org/10.3389/feart.2022.891319.
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The entanglement between active tectonics and karst systems is well-known in the literature. Karst systems are sound recorders of continental deformation in terms of brittle structures and seismic features and have been successfully used as markers for reconstructing tectonic stresses and assessing preferential directions of increased permeability in oil and gas fields. Karst systems could also be exploited to evaluate the past activity of faults bounding karst hydrostructures, thus providing useful data for the assessment of the seismic hazard of a specific area. In this work, we look into the complex relationship among karst development, recent tectonics and groundwater flow, which appear to be strongly interconnected with each other, to assess the activity of faults bounding karst hydrostructures. We focused our attention on an active karst area located in the Mesozoic and Cenozoic carbonate reliefs of the Italian central Apennines. In this context, the morphological and morphometric features of the karst landforms (dolines, dry valleys, and cave entrances), identified with geomorphological surveys, and their mutual relationship with fractures and fault segments, identified employing geostructural analysis, document stasis and deepening events in karst evolution. Such events are related to changes in the groundwater table and the consequent variation of the paleokarst base level associated with the Quaternary fault activity. A comprehensive evaluation of the evolution of karst systems at local and regional scales, considering the hydrogeological influence on base levels, allows us to use karst landforms as a proxy to unravel fault activity and evolution in Italy and in other similar karst environments.