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A comprehensive study, including geological mapping, structural and thermochronological analysis, has been carried out on Ivanščica Mountain (NW Croatia), with the aim to reconstruct the tectonic history of the Dinarides, Southern/Eastern Alps and Pannonian Basin transitional zone. Implementation of structural and thermochronological methods enabled a subdivision of Ivanščica Mt. into two structural domains (from bottom to top): Ivanščica Parautochthon and Ivanščica Imbricate Fan and Cenozoic sedimentary cover. In addition, a sequence of deformational events in tectonic history of this transitional zone is proposed, comprising three extensional and four contractional events starting from Middle Triassic until present times. The two oldest deformational events indicate Middle Triassic (D1) and Early Jurassic (D2) extensional pulses and only occur in volcano-sedimentary successions of the Ivanščica Mt. The oldest contractional event (D3) is related to the obduction of a Neotethyan ophiolitic mélange over an Upper Triassic to Lower Cretaceous succession of the eastern margin of the Adriatic microplate, which resulted in thermal overprint of the Ivanščica Imbricate Fan structural domain in Berriasian—Valanginian times (~ 140 Ma). This event was soon followed by a second contractional event (D4), which resulted in thrusting and imbrication of the Adriatic passive margin successions together with previously emplaced ophiolitic mélange, thermal overprint of the footwall successions, fast exhumation and erosion. Apatite fission track data together with syn-tectonic deposits indicate an Hauterivian to Albian age of this D4 event (~ 133–100 Ma). These Mesozoic structures were dextrally rotated in post-Oligocene times and brought from the initially typically Dinaridic SE striking and SW verging structures to the recent SW striking and NW verging structures. The following extensional event (D5) is associated with the formation of SE striking and mostly NE dipping normal listric faults, and ENE striking dextral faults accommodating top-NE extension in the Pannonian Basin. Deformations were coupled with hanging wall sedimentation of Ottnangian to middle Badenian (middle Burdigalian to upper Langhian; ~ 18–14 Ma) syn-rift deposit as observed from the reflection seismic and well data. A short-lasting contraction (D6) was registered in the late Sarmatian (late Serravallian; ~ 12 Ma). The youngest documented deformational event (D7) resulted in reactivation of ENE striking dextral faults, formation of SE striking dextral faults as well as the formation of E to ENE trending folds and reverse faults. This event corresponds to late Pannonian (late Messinian; ~ 6 Ma) to Present NNW-SSE contraction driven by the indentation and counterclockwise rotation of Adriatic microplate. Recognized tectonic events and their timings indicate that Ivanščica was mainly affected by deformational phases related to the Mesozoic evolution of the Neotethys Ocean as well as Cenozoic opening and inversion of the Pannonian Basin. Therefore, the Mesozoic tectono-sedimentary evolution of Ivanščica Mountain proves the paleogeographic affiliation of its non-ophiolitic Mesozoic structural-stratigraphic entities to the Pre-Karst unit of the Dinarides. [ABSTRACT FROM AUTHOR]

Chandarpur–Raipur sequence in Chattisgarh basin is represented as siliciclastic-dominated Chandarpur Group and carbonate-dominated Raipur Group. Here, we introduce 'Devsagar Sandstone Member', the only sandstone-dominated member in the carbonate-dominated Charmuria Formation of Raipur Group, that marks a period of rapid siliciclastic deposition identifying a phase of forced regression between two carbonate platforms of Charmuria–Chandi formations, thereby indicating a drastic change in palaeogeography of Raipur Group. In addition, this study revised the litho-stratigraphy of Mesoproterozoic Chattisgarh basin to clarify the confusion raised due to the existence of different stratigraphy in different basinal parts and different nomenclature for the same lithologic units. Detailed geological mapping with facies analysis in the eastern part of the basin manifests the entire basin-fill succession as part of the Chattisgarh basin itself, rather than sub-dividing some parts as Baradwar sub-basin and Singhora proto-basin. Singhora Group deposited in Singhora proto-basin has already been presented as equivalent of Chandarpur Group. Here we propose, Bamandihi–Saradih–Raigarh formations of Raipur Group in Baradwar sub-basin, as lateral equivalent of Gunderdehi–Chandi–Tarenga formations of Raipur Group and Sarnadih–Nandeli formations of Kharsiya Group in Chattisgarh basin. Inferred depositional environment and tectonic setting of Chattisgarh basin support the lithostratigraphic revision, which will help in basin analysis as well as intrabasinal–interbasinal correlation in regional and global contexts. Research highlights: Devsagar Sandstone Member introduced as the only sandstone-dominated member in carbonate-dominated Charmuria Formation of Raipur Group. Devsagar Sandstone Member represents a tidal shelf in between two carbonate ramp platforms (Charmuria and Chandi), marking a period of rapid siliciclastic deposition and the only phase of forced regression in overall sea-level rising scenario of the carbonate-dominated Raipur Group. Stratigraphy of Chattisgarh basin revised. The entire Chattisgarh succession is represented as deposits of Chattisgarh basin only, without further subdivision into sub-basin and/or proto-basin, thus resolving the stratigraphic and basinal correlation problem. [ABSTRACT FROM AUTHOR]

The selection of an optimal dataset is crucial for successful remote sensing analysis. The PRISMA hyperspectral sensor (with 240 spectral bands) and Landsat OLI-2 (boasting high dynamic resolution) offer robust data for various remote sensing applications, anticipating their increased demand in the coming years. However, despite their potential, we have not identified a rigorous evaluation of both datasets in geological applications utilizing Machine Learning Algorithms. Consequently, we conduct a comprehensive analysis using Random Forest, a widely-recommended machine learning algorithm, and employ K-fold cross-validation (with K = 2, 5, 10) with grid-search hyperparameter tuning for enhanced performance. Toward this aim, diverse image-processing approaches, including Principal Component Analysis (PCA), Minimum Noise Fraction (MNF), and Independent Component Analysis (ICA), were applied to enhance feature selection and extraction. Subsequently, to ensure better performance of the RF algorithm, this study utilized well-distributed points instead of polygons to represent each target, thereby mitigating the effects of spatial autocorrelation. Our results reveal dataset-hyperparameter dependencies, with PRISMA mainly influenced by max_depth and Landsat 9 by max_features. Employing grid-search optimally balances dataset characteristics and data splitting (folds), generating accurate lithological maps across all K values. Notably, a significant hyperparameter shift at K = 10 produces the best lithological maps. Fieldwork and petrographic investigations validate the lithological maps, indicating PRISMA's slight superiority over Landsat OLI-2. Despite this, given the dataset nature and band count difference, we still advocate Landsat 9 as a potent multispectral input for future applications due to its superior radiometric resolution. [ABSTRACT FROM AUTHOR]

Gravity measurements have uses in a wide range of fields including geological mapping and mine-shaft inspection. The specific application under consideration sets limits on the survey and the amount of information that can be obtained. For example, in a conventional gravity survey at the Earth's surface a gravimeter is translated on a two-dimensional planar grid taking measurements of the vertical component of gravity. If, however, the survey points cannot be chosen so freely, for example if the gravimeter is constrained to operate in a tunnel where only a one-dimensional line of data could be taken, less information will be obtained. To address this situation, we investigate an alternative approach, in the form of an instrument which rotates around a central point measuring the gravitational potential or its radial derivative on the boundary of a sphere. The ability to record additional components of gravity by rotating the gravimeter will give more information than obtained with a single measurement traditionally taken at each point on a survey, consequently reducing ambiguities in interpretation. We term a device which measures the potential, or its radial derivatives, around the surface of a sphere a gravitational eye. In this article we explore ideas of resolution and propose a thought experiment for comparing the performance of diverse types of gravitational eye. We also discuss radial analytic continuation towards sources of gravity and the resulting resolution enhancement, before finally discussing the possibility of using cold-atom gravimetry and gradiometry to construct a gravitational eye. If realised, the gravitational eye will offer revolutionary capability enabling the maximum information to be obtained about features in all directions around it. [ABSTRACT FROM AUTHOR]

The information obtained from direct data (geological mapping and boreholes) and indirect techniques (reflection seismology, time-domain electromagnetics and magnetometry) is combined to analyse the northern limit of the Bailén basin (southeastern Spain). This Triassic–Neogene basin is confined by a graben-type structure, limited by two normal faults in the SW–NE direction (the Baños de la Encina-La Carolina fault and Guarromán fault). The movement of these faults was complex, with different pulses occurring over time. Therefore, the subsidence of the basin and the sedimentary filling of the graben were different, giving rise to lateral changes in the facies and thicknesses. This study focuses on the Baños de la Encina fault, chosen as the experimental site to analyse the effectiveness and accuracy of these geophysical techniques to reveal the basement structure and geometry. Seismic reflection allows to detect two faults that caused the subsidence of the eastern sector of the graben. The TDEM method made it possible to calculate the depth of the Palaeozoic basement, as well as reveal the presence of the two aforementioned faults. Magnetic total field data highlight variations in the basement depth that can be used to infer previously unknown fractures, in this case, in the NW–SE direction. [ABSTRACT FROM AUTHOR]

The Mineral King pendant is an ~15-km-long, northwest-striking assemblage of Permian to mid-Cretaceous metavolcanic and metasedimentary rocks that form a steeply dipping wall-rock screen between large mid-Cretaceous plutons of the Sierra Nevada batholith (California, USA). Pendant rocks are generally well layered and characterized by northwest-striking, steeply dipping, layer-parallel cleavage and flattening foliation and steeply northwest-plunging stretching lineation. Northwest-elongate lithologic units with well-developed parallel layering and an absence of prominent faults or shear zones suggests a degree of stratigraphic continuity. However, U-Pb zircon dating of felsic metavolcanic and volcanosedimentary rocks across the pendant indicates a complex pattern of structurally interleaved units with ages ranging from 277 Ma to 101 Ma. We utilize a compilation of 39 existing and new U-Pb zircon ages and four reported fossil localities to construct a revised geologic map of the Mineral King pendant that emphasizes age relationships rather than lithologic or stratigraphic correlations as in previous studies. We find that apparently coherent lithologic units are lensoidal and discontinuous and are cryptically interleaved at meter to kilometer scales. Along-strike facies changes and depositional unconformities combine with kilometer-scale tight folding and structural imbrication to create a complex map pattern with numerous discordant units. Discrete faults or major shear zones are not readily apparent in the pendant, although such structures are necessary to produce the structural complications revealed by our new mapping and U-Pb dating. We interpret the Mineral King pendant to be structurally imbricated by a combination of kilometer-scale tight to isoclinal folding and cryptic faulting, accentuated by, and eventually obscured by, pervasive flattening and vertical stretching that preceded and accompanied emplacement of the bounding mid-Cretaceous plutons. Deformation in the Mineral King pendant represents a significant episode of pure-shear-dominated transpression between ca. 115 Ma and 98 Ma that adds to growing evidence for a major mid-Cretaceous transpressional orogenic event affecting the western U.S. Cordillera. [ABSTRACT FROM AUTHOR]

Since the 2015 Gorkha earthquake in Nepal, the relationship between the geometry of megathrusts and the control it exerts over the nucleation and propagation of major earthquakes has become an important topic of debate. In this study, we integrate new geologic mapping, a newly interpreted cross section from the Daraundi valley of central Nepal, two published cross sections from the neighboring Marsyangdi and Budhi Gandaki valleys, and a suite of 270 thermochronometric ages to create an integrated and validated three-dimensional kinematic model for the central Nepal Himalaya. We use this model to investigate the assertion that the westward propagation of the Gorkha rupture was restricted by deep-seated structures in the Main Himalayan thrust. The integrated kinematic model based on these cross sections indicates that the ~30 km southward step in the Main Central thrust system mapped in the Daraundi valley, along with the corresponding step in the distribution of reset muscovite (Ar-Ar) ages, is not the result of a lateral structure in the modern Main Himalayan thrust. Instead, the step in the surface geology is the result of a considerably shorter Trishuli thrust sheet in the Daraundi transect (~30 km compared to between 105 and 120 km in the other transects). The corresponding southward step in the distribution of reset muscovite Ar-Ar ages is the result of the Lesser Himalayan duplex being completely translated over the Main Himalayan thrust ramp, elevating and exposing rocks heated to >400 °C farther south in the Daraundi transect. Our integrated model also highlights the 10–15 km of out-of-sequence thrusting that occurs on the Main Central thrust system across central Nepal. Importantly, these out-of-sequence thrusts sole directly into the modern Main Himalayan thrust ramp, and, together with the distribution of reset zircon (U-Th)/He and apatite fission track ages, show that the modern ramp is distinctly linear from east to west, with no support for a lateral structure at the ramp or to the south. [ABSTRACT FROM AUTHOR]

The latest geological and geophysical information on the Zeya-Bureya sedimentary basin (Russia, Far East) is summarized. Based on drilling data from corehole and deep wells and 2D and 3D CDPM seismic data, taking into account the integrated interpretation of gravity and magnetic survey data and geological survey materials, a map was compiled for the surface of the pre-Mesozoic basement of the sedimentary basin, as well as structural maps for the top of the Cretaceous formations. The maps reflect a series of rift grabens and uplifts identified by the authors on seismic time sections during their reinterpretation. The method of compiling maps is given. A geological map of sediments overlying the pre-Mesozoic basement of the Zeya-Bureya sedimentary basin and a tectonic map of the sedimentary cover were compiled. During tectonic zoning of the sedimentary cover, the classification of tectonic elements was adopted that is widely used in the tectonic zoning of oil and gas regions, proposed by V.D. Nalivkin and updated at the Trofimuk Institute of Oil and Gas Geology and Geophysics, Siberian Branch, Russian Academy of Sciences (INGG SB RAS). As a result of tectonic zoning in the basin, the Inner Region and the Outer Belt were identified, and the tectonic elements complicating them were characterized. A characteristic feature of the Outer Belt is the presence of large intermediate structures: monoclines and mega- and mesomonoclines. Conversely, the Inner region of the basin is characterized by the presence of a large negative structure, complicated by smaller positive and negative elements. The main stages of the formation and development of the sedimentary cover of the Zeya-Bureya sedimentary basin are identified and described: rifting, early syneclise, late syneclise, and neotectonic. [ABSTRACT FROM AUTHOR]

Mineral exploration works conducted in the Alto Guaporé Gold Province (AGGP), situated in the southwest region of the Amazon Craton in Brazil, faces the challenges of many gold provinces around the world, i.e., declines in the discoveries of new economic deposits and increases in exploration costs. Ground geophysical methods, combined with structural analyses and geological mapping, are valuable tools that have potential to improve accuracy in selecting exploration targets and in determining drilling locations. AGGP deposits are primarily associated with regional N20°–W50° inverse faulting and sheared geologic contacts between Meso-Neoproterozoic siliciclastic metasedimentary rocks and Mesoproterozoic basement (granite and volcano–sedimentary sequences). Mining currently occurring in the central portion of the province drives exploration works towards the many existing targets at the area. Among them, the ABP target is one of the most promising for being located few kilometers north of the Pau-a-Pique mine. At the ABP target, gold is associated with hydrothermal alteration located in the sheared contacts and in the hinge zone of folded metasedimentary sequence. Hydrothermal phases include Fe-oxides, sulfide (py), muscovite and quartz veins. In this study, we use magnetic and geoelectric (induced polarization) surveys coupled with structural and geological mapping to identify potential footprints within the ABP target. The results from induced polarization (IP) profiles successfully mapped the shape and orientation of the main structures down to approximately 350 m at the ABP target, indicating potential locations for hydrothermal alteration hosting gold. Additionally, 3D magnetic data inversions illustrated the distribution of magnetic susceptibilities and magnetization vectors associated with shear zone structures and isolated magnetic bodies. Magnetic data highlighted fault zones along the contacts between metamorphic rocks and granites, while IP data identified areas with high chargeability, correlating with sulfidation zones mineralized with gold. These findings suggest a metallogenic model where gold deposits are transported through deep structures connected to regional faults, implying significant tectonic and structural control over gold deposition. The results underscore the potential of multiparameter geophysics in identifying and characterizing deposits in both deep and strike, thereby advancing our understanding of mineral occurrences in the region and enhancing the search for new mineralized zones. [ABSTRACT FROM AUTHOR]

The main aim of the study is to perform a high-precision mapping of geological features (lineaments and faults) using advanced gravity processing methods. The main techniques used for gravity data processing are the tilt angle of horizontal gradient (TAHG), the improved logistic filter (ILF), the fast sigmoid edge detector filter (FSF), and an edge detection filter based on the arcsine function (ASF). Before applying these edge detection filters to major geological units of North Cameroon, their effectiveness and performance have been assessed on synthetic gravity data and on random noise incorporated synthetic data. In addition, the Euler deconvolution has been used to estimate the position and depth of anomalous gravity sources in the study region. Using these edge detection techniques, a precise mapping of structural lineaments in the region has been established. It appears that the main structural features are trending along the N-S, NNE-SSW and NE-SW directions. The deepest density anomalies in the region are identified in the NW–SE direction, which coincides well with the extension of the Central and West African rift system in the study area. The advanced edge detection techniques and the Euler deconvolution method have both identified a network of superficial lineaments around longitude 13oN and latitude 8oN, and located between 0 and 4 km depth. The NW–SE trending crustal features outlined in the northeast of the region indicate that the area would have been the target of a uniform tectonic activity. This study is crucial to improve the knowledge of the configuration of fractures network, and to a better exploitation of groundwater resources available in the region. [ABSTRACT FROM AUTHOR]

Remote sensing observations represent the primary means in the production of geologic maps of planetary surfaces. However, they do not provide the same level of detail as Earth's geologic maps, which rely also on field observations and laboratory analyses. Color‐derived basemaps can help to bridge this gap by highlighting peculiar surface and compositional properties. Here, we analyzed the spectral properties of the lunar Tsiolkovskiy crater through the definition of spectral units summarizing the information enclosed by a set of selected spectral parameters. We then performed a compositional analysis of the newly derived spectral units that helped us in discriminating the presence and relative abundance of the main mineralogical phases on the Moon. As a final step, we produced a geo‐stratigraphic map of the Tsiolkovskiy crater integrating in a single mapping product both morphologic, stratigraphic and compositional information. The basaltic infilling of the crater is distinguished by three spectral units associated with distinct effusive events presenting a different composition. On the central peak, plagioclase and olivine suggest the presence of Mg‐suite rocks from the lower crust. The continuous ejecta deposits are mostly characterized by impact melts and shocked materials rich in glass or agglutinates related to more mature terrains from which occasionally appear fresher anorthositic and gabbroic outcrops exposed by the inward sliding of the crater walls. Overall, the geo‐stratigraphic map allows inferring compositional variations associated with the different morpho‐stratigraphic units, which clarify and elaborate on the compositional heterogeneities within the lunar crust and the Tsiolkovskiy crater, and its geologic evolutionary history. Plain Language Summary: The main data used to produce geologic maps of planetary surfaces come from orbiting missions. However, geologic maps of Earth provide much more information, relying also on observations made on the field and analyses made in the laboratory. Color images derived from the combination and processing of spectral information can help to make planetary maps more comprehensive, similarly to the Earth's ones, by drawing attention to surface and compositional aspects. In this work, we performed a spectral and compositional study of the Tsiolkovskiy crater on the Moon which enabled us to distinguish the presence and relative quantity of the most common minerals constituting the lunar rocks. We also produced a geo‐stratigraphic map coupling the information about the surface textures and shapes, relative time of deposition, and composition. On the basaltic floor, we discriminated the presence of three different spectral characteristics correlated with a sequence of flooding events showing distinct properties and a central peak exhibiting rocks emerged from the lowest strata of the lunar crust. The continuous ejecta blanket, instead, is characterized by mature materials interspersed by fresher exposures of subsurface materials. To conclude, the new mapping product allows an in‐depth interpretation of the geologic evolution of the Tsiolkovskiy crater. Key Points: Production of a 10‐unit Spectral Units map conveying the spectral and compositional properties within the Tsiolkovskiy craterIntegration of geologic and spectral units to produce a more comprehensive mapping product, namely a geo‐stratigraphic mapElaboration on the geological and compositional evolution of our study area [ABSTRACT FROM AUTHOR]

Machine learning and remote sensing techniques are widely accepted as valuable, cost-effective tools in lithological discrimination and mineralogical investigations. The current study represents an attempt to use machine learning classification along with several remote sensing techniques being applied to Landsat-8/9 satellite data to discriminate the various outcropping lithological rock units at the Duwi Shear Belt (DSB) area in the Central Eastern Desert of Egypt. Multi-class machine learning classification, multiple conventional remote sensing mapping techniques, spectral separability analysis based on the Jeffries-Matusita (J-M) distance measure, fieldwork, and petrographic investigations were integrated to enhance the lithological discrimination of the exposed rock units at DSB area. The well-recognized machine learning classifier (Support Vector Machine—SVM) was adopted in this study, with training data determined carefully based on enhancing the lithological discrimination attained from various remote sensing techniques of False Color Composites (FCC), Principal Component Analysis (PCA), and Minimum Noise Fraction (MNF), along with the fieldwork data and the previously published geologic maps. High overall accuracy of the SVM classification was obtained, however, inspection of the individual rock unit classes' accuracies revealed lower accuracy for certain types of rock units which were also found associated with lower separability scores as well. Among the least separable rock units were; metagabbro rocks that showed high spectral similarity with the volcaniclastic metasediments rocks, and the metaultramafics of the ophiolitic mélange showed spectral attitude of high correlation to that of the Hammamat volcanosedimentary rocks. Target-oriented Color Ratio Composites (CRC) technique was implemented to better discriminate these hardly separable rock units. A final integrated geological map was obtained comprising the various discriminated Neoproterozoic basement rock units of the DSB area. The successfully mapped litho-units include; Meatiq Group (amphibolites, gneissic granitoids, and mylonitized granitoids), ophiolitic mélange (metaultramafics, metagabbro-amphibolites, and volcaniclastic metasediments), Dokhan volcanics, Hammamat sediments, and granites. An adequate description of these rock units was also given in light of the conducted intense fieldwork and petrographic investigations. [ABSTRACT FROM AUTHOR]

Geological mapping involves the identification of elements such as rocks, soils, and surface water, which are fundamental tasks in Geological Environment Remote Sensing (GERS) interpretation. High-precision intelligent interpretation technology can not only reduce labor requirements and significantly improve the efficiency of geological mapping but also assist geological disaster prevention assessment and resource exploration. However, the high interclass similarity, high intraclass variability, gradational boundaries, and complex distributional characteristics of GERS elements coupled with the difficulty of manual labeling and the interference of imaging noise, all limit the accuracy of DL-based methods in wide-area GERS interpretation. We propose a Transformer-based multi-stage and multi-scale fusion network, RSWFormer (Rock–Soil–Water Network with Transformer), for geological mapping of spatially large areas. RSWFormer first uses a Multi-stage Geosemantic Hierarchical Sampling (MGHS) module to extract geological information and high-dimensional features at different scales from local to global, and then uses a Multi-scale Geological Context Enhancement (MGCE) module to fuse geological semantic information at different scales to enhance the understanding of contextual semantics. The cascade of the two modules is designed to enhance the interpretation and performance of GERS elements in geologically complex areas. The high mountainous and hilly areas located in western China were selected as the research area. A multi-source geological remote sensing dataset containing diverse GERS feature categories and complex lithological characteristics, Multi-GL9, is constructed to fill the significant gaps in the datasets required for extensive GERS. Using overall accuracy as the evaluation index, RSWFormer achieves 92.15% and 80.23% on the Gaofen-2 and Landsat-8 datasets, respectively, surpassing existing methods. Experiments show that RSWFormer has excellent performance and wide applicability in geological mapping tasks. [ABSTRACT FROM AUTHOR]

During the sampling of a stratigraphic section along the shore of the Fiastra Lake (Carg Project - Sheet 313 “Camerino” of the Geological Map of Italy at 1:50 000 scale), a small rock boulder with partially exposed bony material was discovered at the base of a small cliff at the northern termination of the Sibillini Mts. In this area, the classical facies of Umbria-Marche stratigraphic succession are well-exposed. The Oligocene-Miocene portion of the succession is represented by the ~200 m-thick Scaglia Cinerea Formation, passing upwards to the ~100 m-thick Bisciaro Formation. The microfossil assemblage has allowed the specimen to be constrained to the lower Burdigalian. The skeletal remains were examined using a CT-SCAN, a non-invasive method that has proven to be highly performing. The analysis revealed some articulated vertebrae, deformed by lithostatic compaction, which are attributed to a shark of the order Lamniformes. Subsequently, the vertebrae were digitally isolated, extracted from the surrounding matrix, and rendered into three-dimensional prints. Through digital retro-deformation, the body length of the lamniform shark was estimated to be approximately 4 metres. Further considerations on the vertebrae allowed us to infer that the studied shark had similarities to either Isurus oxyrinchus Rafinesque, 1810 or Carcharodon carcharias Linnaeus, 1758. The development of a dead-fall microbial community likely facilitated the preservation of the vertebrae. The studied specimen represents the first occurrence of a lamniform shark in the Lower Miocene of the Umbria-Marche Domain and represents one of the very rare recorded occurrences of lamniforms from the Lower Miocene of Italy [ABSTRACT FROM AUTHOR]

Apart from within the Arumbera Sandstone that spans the Ediacaran–Cambrian boundary, the entire Neoproterozoic succession of the Amadeus Basin has been generally believed to be devoid of metazoan fossils, despite features of possible biogenic origin having been described in the earliest geological mapping reports. Herein are described a suite of curious, rounded impressions preserved upon the surface of a sandstone bed from the basal Neoproterozoic unit, the quartzitic Heavitree Formation that dates to ca 850 Ma. Compared with rounded structures of both organic and inorganic origin, these features resemble fossils of stranded medusae, both modern and ancient, and thereby add a potentially pelagic lifeform to previously described burrowing and sessile forms of likely metazoans, which are preserved as fossils/trace fossils within the Tonian period of the Neoproterozoic elsewhere in the basin. An organic origin for these features would support the contention that the Amadeus Basin harbours the earliest evidence that macroscopic life flourished, albeit briefly, some 215 million years prior to the start of the Ediacaran period and 250 million years before metazoans successfully colonised the late Ediacaran seas. Curious rounded impressions upon a scree sample of Heavitree Formation (ca 850 Ma) are best compared with fossils of stranded jellyfish, both modern and ancient. Such impressions add to the phyla seemingly extant within the Amadeus Basin during the Tonian Period (early Neoproterozoic). Such phyla suggest that metazoan life evolved some 250 Ma earlier than generally believed, although became extinct locally some 10 Ma later. Extinction occurred at ca 840 Ma when changing climate caused the enclosed Amadeus Basin to evolve from conducive shallow aquatic conditions to a harsh evaporitic salt pan. Two later forays into metazoan evolution within the basin are evidenced by burrow-like tubular structures at ca 720 Ma and the Arumberia fossils at ca 560 Ma. [ABSTRACT FROM AUTHOR]

The Elat/Timna area in Southern Israel provides an unparalleled opportunity for geological field studies due to its unique geology, spanning from the Neoproterozoic to the Holocene. The well-exposed rocks document the variability and evolution of three major processes: the creation of the Arabian-Nubian Shield during the Neoproterozoic, the accumulation of the Cambrian to Eocene sedimentary sequence, and the Miocene to Recent evolution of the Dead Sea Transform, an active plate boundary. The area's geological diversity and extensive documentation of its geology have made it a particularly important study site for geoscience students. Recently the Geological Survey of Israel published new 1:50,000 scale geological maps of the area, updated by additional fieldwork and presented in a series of reports. This paper presents a brief geological overview and a description of six key locations, complete with maps and photos that are a showcase document to the area's geological uniqueness as an excellently-exposed window into 800 million years of Neoproterozoic to Holocene evolution at the NE African plate. [ABSTRACT FROM AUTHOR]

The evolution of map development has been shaped by advancing techniques and technologies. Nevertheless, field and remote mapping with cabinet data analysis remains essential in this process. Geological maps are thematic maps that delineate diverse geological features. These maps undergo updates reflecting changes in the mapped area, technological advancements, and the availability of new data. Herein, a geological assessment example focused on enhancing mapped data using digitally processed historical (legacy) aerial images is presented for a case study in the Dinarides karst area in Croatia. The study area of Bribirske Mostine is covered by the Basic Geological Map of Yugoslavia (BGMY) at a 100,000 scale, which was developed during the 1960s. As the BGMY was developed 60+ years ago, one of its segments is further analyzed and discussed, namely, faults. Moreover, applying modern-day technologies and reinterpretation, its data, scale, presentation, and possible areas of improvement are presented. Georeferenced digital historical geological data (legacy), comprising BGMY, archive field maps, and aerial images from 1959 used in BGMY development, are reviewed. Original faults were digitalized and reinterpreted within the geographic information system with the following conclusions: (i) more accurate data (spatial positioning) on faults can be gained by digitally processing aerial photographs taken 60+ years ago with detailed review and analysis; (ii) simultaneously, new data were acquired (additional fault lines were interpreted); (iii) the map scale can be up-scaled to 1:25,000 for the investigated area of Bribirske Mostine; and (iv) a newly developed map for the Bribirske Mostine study area is presented. [ABSTRACT FROM AUTHOR]

This paper aims to achieve bedrock geologic mapping in the overburden area using big data, distributed computing, and deep learning techniques. First, the satellite Bouguer gravity anomaly with a resolution of 2'x2' in the range of E66°E96°, N40°-N55° and 1:5000000 Asia-European geological map are used to design a dataset for bedrock prediction. Then, starting from the gravity anomaly formula in the spherical coordinate system, we deduce the non-linear functional between rock density ρ and rock mineral composition m, content p, buried depth h, diagenesis time t and other variables. We analyze the feasibility of using deep neural network to approximate the above nonlinear generalization. The problem of solving deep neural network parameters is transformed into a non-convex optimization problem. We give an iterative, gradient descentbased solution algorithm for the non-convex optimization problem. Utilizing neural architecture search (NAS) and human-designed approach, we propose a geological-geophysical mapping network (GGMNet). The dataset for the network consists of both gravity anomaly and a priori geological information. The network has fast convergence speed and stable iteration during the training process. It also has better performance than a single neural network search or human-designed architectures, with the mean pixel accuracy (MAP) = 63.1% and the frequency weighted intersection over union (FWIoU) = 42.88. Finally, the GGMNet is used to predict the rock distribution of the Junggar Basin. [ABSTRACT FROM AUTHOR]

Meteoroid impacts produce different types of fractures and damage zones beneath impact craters. The 3D geometry of these features reflects the trajectory and energetics of an impact event. In this study, we mapped the impact damage zone beneath the 1.88‐km‐diameter Lonar crater, emplaced in Deccan basalts, using Ambient Noise Tomography (ANT). A network of 23 broadband seismic stations in and around the crater yielded a 1.2 km deep 3D shear wave velocity (VS) image covering ∼7 km by ∼5 km area. It revealed ∼500–900‐m‐thick heterogeneous target basalt flows, underlain by an undulating Archean granite‐gneiss basement. A substantial reduction in VS is observed beneath the crater. The original crater floor was found at a depth of 400 m below the crater rim, which is filled by impact breccia and lake sediments. Beneath the original floor, we found an oval‐shaped, asymmetric 200‐m‐thick lensoidal low‐velocity layer with a tongue‐like feature beneath the southwestern ejecta blanket. The damage zone is inferred to have formed as a result of oblique impact, in which the projectile arrived from northeast to southwest direction. The VS reduction in the low‐velocity layer was used to calculate the amount of impact damage in it. The oblique impact produced a more elevated southwestern crater rim. Impact‐related near‐surface fracture zones up to a radial distance of >1 km beneath the ejecta blanket were also found. We suggest that impact damage beneath impact craters on Earth and other planetary bodies may be imaged using ANT. Plain Language Summary: Impact craters are ubiquitous on planetary surfaces. The impact produces both surface and sub‐surface changes, including fracturing and damage beneath the crater floor. The 3D geometry of the damage zone depends on the impact angle and velocity. While vertical impacts generate symmetric damage zones beneath the craters, oblique impacts produce asymmetrical damage zones with greater damage in the downrange direction. Field geological mapping provides limited information about these features, while the Ambient Noise Tomography (ANT) brings out a complete shape and size of the damage zone in the sub‐surface. The shear wave velocity image also provides the characteristics of target rocks within and outside the impact crater. In this work, we carried out the ANT study of Lonar crater, emplaced in Deccan basalts in India, using a network of 23 broadband seismometers. This study revealed a ∼500–900‐m‐thick heterogeneous basaltic target underlain by an Archean granite‐gneiss basement, and an asymmetric damage zone beneath ∼400‐m‐deep original crater floor because of southwest directed oblique impact. We quantified the amount of impact damage beneath the original crater floor. The ANT can be used for imaging damage zones beneath impact craters on Earth and other solid planetary bodies, thus providing more insight into impactor trajectories. Key Points: Ambient noise tomography reveals a 500–900 m thick heterogeneous basaltic target underlain by Archean granite basement beneath Lonar craterAn asymmetric damage zone is found beneath the 400 m deep original crater floor filled by impact breccia and lake sedimentsAsymmetric topography and impact damage zone geometry are consistent with a southwest‐ward oblique impact trajectory [ABSTRACT FROM AUTHOR]

This study presents a comprehensive assessment of the geomorphology, crater distributions, and tectonic structures within Enceladus' cratered terrains. We analyzed the distributions of impact craters and tectonic structures in seven regions of interest to inform an interpretation of the geological history of this terrain in the context of Enceladus' global evolution. We found that the tectonic structures, including both ancient, subdued troughs and young, narrow fractures, point to a cratered terrain that not only experienced early tectonic modification but also shows evidence of recent geological activity. Ancient troughs present in the equatorial cratered terrains are similar in scale and orientation to troughs present in the Leading and Trailing Hemisphere Terrains, an observation that supports possible non‐synchronous rotation of the ice shell. A dearth of impact craters in the equatorial regions as identified previously does not hold for craters <3 km in diameter in the anti‐Saturnian hemisphere. The anomalous presence of excess small craters in this region could be due to secondary or sesquinary impacts from a catastrophic event occurring at Enceladus or a neighboring moon. Finally, narrow fractures are pervasive across the cratered terrains and are most commonly oriented parallel or sub‐parallel to the most proximal cratered terrain boundary. This directionality of pervasive recent fracturing could be related to the vertical movement of an isostatically uncompensated ice shell. Enceladus' cratered terrains provide insight into the long‐term evolution of the satellite, an important component to assessing its role in Solar System evolution and its potential for habitability. Plain Language Summary: We present a comprehensive characterization of the oldest terrain on Enceladus, the cratered terrains. We evaluated structural features and impact craters on the surface, including their morphology and spatial distributions. This analysis informs how we interpret the formation and change of these surface features in the context of how Enceladus as a whole has changed over time. We found that there are two main types of tectonic structures in the cratered terrains, including one set of relatively old troughs and at least one set of narrow fractures that is very young. This finding indicates that not only have the cratered terrains experienced early tectonic activity, but were also active recently. The ancient set of troughs are similar to those present in younger terrains on Enceladus, suggesting that the ice shell has rotated relative to its tidally locked position about Saturn. The comparatively young, narrow fractures in the cratered terrains are widespread and could have formed due to a vertically shifting ice shell. Enceladus' cratered terrains provide insight into what long‐term changes have taken place on the surface, an important component to understanding how Enceladus fits into Solar System formation and its past or present potential to host life. Key Points: Systematic review of Enceladus' cratered terrains results in a stratigraphic framework for geologic mapping and age determinationTroughs in the equatorial cratered terrains are similar to tectonized equatorial regions, suggesting non‐synchronous ice shell rotationAncient, subdued troughs and young, narrow fractures point to a cratered terrain that experienced both early and recent tectonic activity [ABSTRACT FROM AUTHOR]

The consumption of fluoride below the safe limit can result in dental caries, while high concentrations can lead to fluorosis, which can potentially impair the body's systems. One geological factor that influences the concentration of fluoride in water is the type of rock through which the water passes, including granite and its weathering products. The area is located within the Tandjungbuku Formation, which is predominantly composed of granite rock and contains several areas with Mining Business Permits (IUP) for commodities such as silica sand. This research serves as a form of mitigation in response to mining activities, post-mining, and the development of an industrial area. One anticipated impact is an increase in fluoride concentration in the research area, originating from both natural geological processes and human activities. The investigation involved geological mapping, petrographic analysis, XRD, and XRF analysis. Water sampling was conducted for both surface water and groundwater from wells in Resang Tandjungbuku Village. The research area consists of two rock units: granite, which acts as a non-aquifer layer, and colluvial deposits, which function as a free aquifer. Petrographic analysis identified minerals associated with fluoride, such as plagioclase, amphibole, and biotite. This was supported by XRD analysis with the presence of biotite, muscovite and kaoline minerals. XRF results revealed fluoride values in granite rock at 0.23% or 2,300 ppm, further confirming granite as a source of fluoride. Analysis of fluoride in surface water showed values ranging from 0.01 to 4.24 mg/L, while groundwater consistently had a value of 0.01 mg/L. [ABSTRACT FROM AUTHOR]

The selection of an optimal dataset is crucial for successful remote sensing analysis. The PRISMA hyperspectral sensor (with 240 spectral bands) and Landsat OLI-2 (boasting high dynamic resolution) offer robust data for various remote sensing applications, anticipating their increased demand in the coming years. However, despite their potential, we have not identified a rigorous evaluation of both datasets in geological applications utilizing Machine Learning Algorithms. Consequently, we conduct a comprehensive analysis using Random Forest, a widely-recommended machine learning algorithm, and employ K-fold cross-validation (with K = 2, 5, 10) with grid-search hyperparameter tuning for enhanced performance. Toward this aim, diverse image-processing approaches, including Principal Component Analysis (PCA), Minimum Noise Fraction (MNF), and Independent Component Analysis (ICA), were applied to enhance feature selection and extraction. Subsequently, to ensure better performance of the RF algorithm, this study utilized well-distributed points instead of polygons to represent each target, thereby mitigating the effects of spatial autocorrelation. Our results reveal dataset-hyperparameter dependencies, with PRISMA mainly influenced by max_depth and Landsat 9 by max_features. Employing grid-search optimally balances dataset characteristics and data splitting (folds), generating accurate lithological maps across all K values. Notably, a significant hyperparameter shift at K = 10 produces the best lithological maps. Fieldwork and petrographic investigations validate the lithological maps, indicating PRISMA’s slight superiority over Landsat OLI-2. Despite this, given the dataset nature and band count difference, we still advocate Landsat 9 as a potent multispectral input for future applications due to its superior radiometric resolution.

The new generation of satellite hyperspectral (HS) sensors provides remarkable potential for regional-scale mineralogical mapping. However, as with any satellite sensor, mapping results are dependent on a typically complex correction procedure needed to remove atmospheric, topographic and geometric distortions before accurate reflectance spectra can be retrieved. These are typically applied by the satellite operators but use different approaches that can yield different results. In this study, we conduct a comparative analysis of PRISMA, EnMAP, and EMIT hyperspectral satellite data, alongside airborne data acquired by the HyMap sensor, to investigate the consistency between these datasets and their suitability for geological mapping. Two sites in Namibia were selected for this comparison, the Marinkas-Quellen and Epembe carbonatite complexes, based on their geological significance, relatively good exposure, arid climate and data availability. We conducted qualitative and three different quantitative comparisons of the hyperspectral data from these sites. These included correlative comparisons of (1) the reflectance values across the visible-near infrared (VNIR) to shortwave infrared (SWIR) spectral ranges, (2) established spectral indices sensitive to minerals we expect in each of the scenes, and (3) spectral abundances estimated using linear unmixing. The results highlighted a notable shift in inter-sensor consistency between the VNIR and SWIR spectral ranges, with the VNIR range being more similar between the compared sensors than the SWIR. Our qualitative comparisons suggest that the SWIR spectra from the EnMAP and EMIT sensors are the most interpretable (show the most distinct absorption features) but that latent features (i.e., endmember abundances) from the HyMap and PRISMA sensors are consistent with geological variations. We conclude that our results reinforce the need for accurate radiometric and topographic corrections, especially for the SWIR range most commonly used for geological mapping. [ABSTRACT FROM AUTHOR]

Characterizing neotectonic activity along mountain fronts in active orogens is the key to better understanding trajectories of landscape evolution, climatic‐tectonic couplings and natural hazards. One such prominent mountain front is the Western Andean Front (WAF), which defines the boundary between two main physiographic units along the Chilean Andes (15°S to 39°S): the Central Depression and Principal Cordillera. This study analyses the geomorphic imprints of neotectonic fault activity in the WAF between 35°S and 37°S. We used several topographic metrics, including the mountain‐front sinuosity index (Smf), the valley floor width‐to‐height ratio (Vf) and the stream length‐gradient (SL) index to gain information about the regional distribution of deformation patterns and its relative tectonic activity for distinctive segments. In addition, a raster map combining rock strength (RS) and mean annual precipitation (MAP) allowed discriminating lithology‐climate vs. tectonics influence on SL anomalies from catchments spanning from the main deformation zone to the regional drainage divide. We use the local relief and swath profiles to quantify the incision and transient state of mountain fronts to evaluate the geomorphic response to tectonic and/or climatic input. Our analysis highlights significant variations from north to south, delineating two distinct segments with different topographic, geomorphic and geometric fault characteristics. These segments are indented at approximately 36°S. From north to south, there is a segment with an inactive thrust front with a primarily climate‐driven fluvial response over long timescales and a second segment with a transient state adjusting to relatively high uplift rates. Morphometric data analysis, DEM‐based morpho‐structural maps, geological maps and previous research support the interpretation of two sets of neotectonic faults: (1) NNE‐striking reverse faults with a dextral slip component and (2) NW‐striking sinistral slip faults, likely a response to deformation partitioning caused by oblique subduction on a continental margin. [ABSTRACT FROM AUTHOR]

We use structure from motion–multiview stereo (SM) terrain models developed from ground-based images and images acquired from uncrewed aircraft (aka drones) as a base map for three-dimensional (3-D) mapping on the walls of a deep canyon in the Panamint Range of eastern California, USA. The ability to manipulate the 3-D model with views from arbitrary look directions and broad scale range revealed structures that were invisible to conventional two-dimensional (2-D) mapping because of both the scale of the structures and their exposure on vertical to near-vertical cliff faces. The analysis supports field evidence for four phases of ductile deformation, with only one of the younger phases documented on early geologic maps of the area. The oldest deformational event (D1) produced the main metamorphic fabric and pre-dates Late Cretaceous plutons. This deformation produced a 200–250-m-thick high-strain zone localized along marbles at the top of the Kingston Peak Formation and lower Noonday Formation. Geometric analysis from the model suggests strongly that large sheath folds at scales of 100–300 m are developed within these marbles. Large measured finite strains indicate displacement across this apparent shear zone of at least 4–5 km and displacements of tens of kilometers are allowable, yet the structure is invisible to conventional mapping because the high-strain zone is stratabound. The main fabric shows two clear overprints and a third that is likely an even younger deformation. D2 and D3 generated tight to close, recumbent folds and open to tight, upright folds, respectively, both folding the main foliation with localized development of crenulation cleavages axial planar to the folds. An additional overprint shows no clear cross-cutting relationship with D2 or D3 fabrics and could be a manifestation of either of those events, although the deformation is spatially limited to a narrow shear zone beneath a brittle, dextral-normal fault with the same kinematics as a mylonitic fabric in a Cretaceous granite in the footwall. This observation suggests an extensional, core complex–style deformation to produce this structure. We suggest that 3-D mapping has the potential to revolutionize geologic mapping studies, particularly where steep topography provides 3-D views that are virtually invisible on conventional 2-D maps. Previously bewildering geologic puzzles can be solved by the ability to visualize large cliff exposures from arbitrary angles and map the features in true 3-D at resolutions to the centimeter level. Although this study emphasized intermediate scales imaged by a drone, our methods here are easily extended to larger scales using a crewed aircraft for imaging. We suggest these methods should be used routinely in frontier areas with steep terrain where aviation is already in use for access, but the methods can be employed anywhere steep terrain “hides” major rock exposures on conventional 2-D maps. [ABSTRACT FROM AUTHOR]

The northwest-trending Altai Mountains of central Asia expose a complex network of thrust and strike-slip faults that are key features accommodating intracontinental crustal shortening related to the Cenozoic India-Asia collision. In this study, we investigated the Quaternary slip history of the Fuyun fault, a right-lateral strike-slip fault bounding the southwestern margin of the Altai Mountains, through geologic mapping, geomorphic surveying, and optically stimulated luminescence (OSL) geochronology. At the Kuoyibagaer site, the Fuyun fault displaces three generations of Pleistocene– Holocene fill-cut river terraces (i.e., T3, T2, and T1) containing landslide and debris-flow deposits. The right-lateral offsets are magnified by erosion of terrace risers, suggesting that river course migration has been faster than slip along the Fuyun fault. The highest Tp2 terrace was abandoned in the middle Pleistocene (150.4 ± 8.1 ka uppermost OSL age) and was displaced 145.5 +45.6/–12.1 m along the Fuyun fault, yielding a slip rate of 1.0 +0.4/–0.1 mm/yr since the middle Pleistocene. The lower Tp1 terrace was abandoned in the late Pleistocene and aggraded by landslides and debris flows in the latest Pleistocene–Holocene (36.7 ± 1.6 ka uppermost OSL age). Tp1 was displaced 67.5 +14.2/–6.1 m along the Fuyun fault, yielding a slip rate of 1.8 +0.5/–0.2 mm/yr since the late Pleistocene. Our preferred minimum slip rate of ~1 mm/yr suggests the Fuyun fault accommodates ~16% of the average geodetic velocity of ~6 mm/yr across the Altai Mountains. Integration of our new Fuyun slip rate with other published fault slip rates accounts for ~4.2 mm/yr of convergence across the Chinese Altai, or ~70% of the geodetic velocity field. [ABSTRACT FROM AUTHOR]

The Sangre de Cristo Mountains of southern Colorado and northern New Mexico, USA, contain an unusual combination of thick- and thin-skinned contractional structures involving both basement and cover rocks in the Laramide Rocky Mountain foreland. These structures are truncated by down-faulted extensional basins to the east and west. Together with synorogenic sediments, these structures preserve a record of the rise of the Ancestral Rocky Mountains, the Laramide orogeny, and Rio Grande rifting. Laramide structures within the mountains provide clues to processes that link the three events and to necessary conditions for thin-skinned and thick-skinned contractional structures to form together in continental interiors. To examine the full variety of structural styles, a portion of the northern Sangre de Cristo fold-and-thrust belt in Colorado was described and interpreted using geologic maps and structural cross-sections. Stratigraphic relations of the Ancestral Rocky Mountain highlands and basin fill were reconstructed from existing maps. These relations allow identification of faults inherited from the Ancestral Rocky Mountains, differentiation of thrust sheets, and in some cases, estimation of the magnitude of displacement. To examine relations between Laramide thrusts and Rio Grande rifting, kinematic data were collected from a thrust fault adjacent to rift faults. Three thrust fault styles were recognized: thin-skinned basement, thinskinned cover rocks, and thick-skinned basement. Thin-skinned thrusts arising from a hinterland beneath the present San Luis Valley carried sheets of Proterozoic basement rocks northeast over a Laramide foreland. These basement thrusts are interpreted to be faults of the Ancestral Rocky Mountains that reactivated during the Laramide orogeny. The Laramide foreland consists of thin-skinned thrusts and folds in sedimentary cover rocks as young as 49 Ma. Both thin-skinned thrusts in basement and cover rocks are bounded by thick-skinned basement thrusts that moved intermittently throughout the Laramide orogeny. We infer that thin-skinned thrusts form in continental interiors where deformation is focused in weak strata of thick basin fill and in fluid-reaction weakened preexisting faults in basement rocks. Both conditions are met in the Sangre de Cristo Mountains. Basement thrusts adjacent to the San Luis Valley contain evidence of plastic contractional microstructures overprinted by extensional microstructures that may record the transition from Laramide contraction to Rio Grande extension of the crust. [ABSTRACT FROM AUTHOR]

The Zagros Mountain range channels a significant volume of water towards the Persian Gulf basin due to the presence of gorges, diverting it from a potential southeast trajectory parallel to the Zagros folds. This study aimed to assess the water flow through the Zagros straits, utilizing 1:50,000 topographic and 1:100,000 geological maps, Iran's Digital Elevation Model (DEM), and various library sources. Hydrometric stations were used as the starting point and their associated sub-basins were delineated. The relationship between precipitation and elevation in each basin was analyzed to extract the precipitation layer of each sub-basin and calculate its average precipitation. Considering the sub-basin areas, the precipitation amount over a specific period was estimated and compared with the recorded discharges. The findings revealed that approximately 110,695 billion cubic meters of water were channeled to the Persian Gulf via the tidal currents of the Zagros Mountains. Notably, the sub-basins with lower discharge relative to the received precipitation, including Gilvan, Simre, Sartang Dolab, Qara Aghaj, and Dez, were situated to the east of the Zagros main thrust, while those with higher discharge were located to the west. This disparity in discharge on either side of the Zagros main thrust could be attributed to various mountain features, such as land surface slope, position in relation to incoming streams, karst, and faulting [ABSTRACT FROM AUTHOR]

We integrate the existing detrital zircon data from multiple modern river sediment samples on Viti Levu, Fiji, with the most current available geological and topographic mapping of the respective river drainage basins to compare detrital populations with potential bedrock sources. The temporal and spatial variations in zircon geochemistry supplement what is known from igneous rocks and confirm the petrological differences between plutonic and volcanic rocks from the Eocene to early Oligocene (Yavuna age, >30 Ma), middle Oligocene to middle Miocene (Wainimala age, 30–12.5 Ma), late Miocene (Colo age, 12.5–6.5 Ma) and latest Miocene (Namosi age, 6.5–5 Ma). The >30 Ma Yavuna-age zircons are restricted to areas that drain the previously mapped Yavuna Group. The 30–12.5 Ma zircons are found across central Viti Levu from west to east, and the 30–15 Ma zircons have distinctively low U/Yb and high Dy/Yb ratios. They are the best radiometric evidence of widespread early to middle Miocene arc magmatism in Fiji that was relatively U-poor. Peak deconvolution of the Colo age zircons from individual basins suggests the following ages for undated or poorly dated plutons from central Viti Levu. The large Mavuvu pluton is probably composed of multiple intrusions in the 12–10 Ma range, the Waiqa pluton is probably ca 10 Ma, and the Noikoro pluton is probably ca 9 Ma. There are zircons from unknown plutonic or volcanic sources between 8 and 7 Ma in western Viti Levu that have distinct Eu/Eu* ratios. We attribute the highest U/Yb ratios in some Colo age zircons to crustal anatexis. Namosi-age zircons are abundant in the Medrausucu Group and can be found scattered across Viti Levu. Detrital zircon samples have aided geological mapping of the tropical and poorly exposed terrain in Fiji and elucidated the magmatic history. Detrital zircons indicate widespread early to middle Miocene arc magmatism across central Viti Levu. Detrital zircon ages have provided further constraints on the ages of 12-9 Ma plutons in central Viti Levu. Detrital zircon ages indicate that there is an unknown igneous source of 8-7 Ma zircons in western Viti Levu. [ABSTRACT FROM AUTHOR]

The Van Lake region is situated within the boundary of the collision zone between the Arabian and Eurasian plates, which has resulted in the formation of a variety of geological structures, including faults, volcanoes, and uplifted mountain ranges. A comprehensive understanding of these structures can yield significant information pertaining to the region's tectonic history, as well as potential tectonic hazards. In the present study, several structural mapping techniques, including lineament detection techniques [Horizontal Gradient Magnitude (HGM), Analytic Signal (AS), and Tilt Angle] and curvature analysis attributes (Differential, Gaussian, Mean, and Shape Index), were analyzed and compared the results obtained using both Earth Gravity Model 2008 (EGM2008) Bouguer gravity and seismological data, with the goal of determining the most effective (suitable) edge detection method in order to gain a better understanding of high-stress regions and areas of potential seismic hazard in the vicinity of Van Lake. It is of great importance to investigate the behavior of faults and the curvatures of structural features within the crust, as they play a significant role in determining the distribution of stress, and subsequently, its impact on surface structures. The results show that HGM and AS are effective in defining fault strikes and trends, while Gaussian curvature attributes can detect lineaments and structural edges. Differential curvature attributes were found to be best suited for complex tectonic regions. The study also reveals a coherent relationship between fold orientation and fault strikes with the regional principal stress direction. The current study has focused on a region characterized by a significant negative anomaly, which appears to be a valley-like fold structure with a highly inclined interlimb angle. This area, referred to as the "silent" zone, is seismically quiet with regard to earthquakes and faults. However, focal mechanism results support the orientation of the interlimb angle fold in the vicinity of this region. The existence of a strong negative anomaly in the eastern part of the study area highlights the requirement for additional geological field observations and seismic surveys to evaluate the potential earthquake hazards. In the course of comparing various structural mapping techniques, it was concluded that the application of second-order vertical derivative of gravity potential is a suggested approach for identifying the edges of causative structures. [ABSTRACT FROM AUTHOR]

This research applies remote sensing methodologies for the first time to comprehensively explore the geological and mineralogical characteristics of the Jbel Bou Dahar region. An integrated approach with multi-sensor satellite images, including ASTER, Landsat-8, and Sentinel-2 was applied with the aim to discriminate the different lithological units in the study area. We implemented a suite of well-established image processing techniques, including Band Ratios, Principal Component Analysis, and Spectral Angle Mapper, to successfully identify, classify, and map the spatial distribution of carbonate minerals, OH-bearing minerals, and iron oxide minerals. Due to its high spectral resolution in the short-wave infrared region (SWIR), the ASTER sensor provided the most accurate results for mapping carbonate and OH-bearing minerals compared to the Sentinel-2 and Landsat-8 sensors. Conversely, Sentinel-2 offers high spectral and spatial resolution in visible and near-infrared (VNIR) corresponding to the regions where iron oxide minerals exhibit their characteristic absorption peaks. The results confirm the advantages of remote sensing technologies in the geological and mineralogical exploration of the study area and the importance of selecting the appropriate sensors for specific mapping objectives. [ABSTRACT FROM AUTHOR]

[Objective] This study focuses on the Gagarin region on the far side of the Moon, aiming to reveal the geological characteristics, distribution features, and genesis of typical areas on the lunar far side. Additionally, it seeks to explore the regional geological evolution history of the Gagarin region. [Methods] The study primarily employs methods such as multi-source remote sensing data interpretation, regional geological mapping, and quantitative analysis of geological elements' quantity and distribution characteristics. [Results] (1) 656 impact craters were discovered in the study area, of which 552 have diameters greater than 20 kilometers. Approximately 71.5% of the Gagarin region is covered by ancient basins and their ejecta from the Aitken period. Based on comprehensive area and diameter data, the Aitken period is identified as the geological era with the largest proportion of large impact craters (diameter greater than 70 kilometers) and the largest average diameter. From the Aitken period to the Copernican period, the total area of impact craters in each geological era shows a decreasing trend from old to new. (2) In the study area, six parallel lunar grabens, 62 lobate scarps, one sinuous rille, 50 crater floor fractures, and 70 shallow faults were discovered. It also includes parts of the two longest inferred deep faults on the Moon, originating from the South Pole-Aitken tectonic zone and almost spanning the entire highland tectonic zone. According to Bouguer gravity anomalies and crustal thickness data, linear crustal thickness anomalies extending outward from the South Pole-Aitken basin reach the major basins on the near side of the Moon. (3) The Gagarin region is primarily located in the anorthositic highlands on the far side of the Moon. The rocks mainly consist of ferroan anorthosite (fa) suites, with some crater floors showing magnesium anorthosite (ma) suites. In the central and southern parts of the Gagarin region, low-titanium (TiO2 > 1.5 and < 4.5) and very low-titanium (TiO2 < 1.5) basalts are sparsely distributed on the floors of certain impact craters and basins. (4) For this study, we selected impact craters such as Aitken and Van der Graaf, with diameters ranging from 350 to 1400 m, for dating analysis. The results of crater size- frequency distribution dating indicate ages of 3.47 GA and 3.32 GA, respectively. (5) The quantitative statistics of impact craters and the dating results of basalt units indicate that the Aitkenian to Imbrian periods were active periods of external dynamic geological processes in the Gagarin region, while the Imbrian period was an active period of internal dynamic geological processes. [Conclusion] (1) The region's longest and deepest faults are the result of the combined effects of the South Pole-Aitken impact event and internal and external stresses, including lunar thermal expansion. (2) The variations in the number and size of impact craters in the Gagarin region on the far side of the Moon are related to the evolution of the Earth-Moon system and the solar system. (3) Based on the quantitative statistical results of impact craters and the dating results of basalt units, this study elucidates the regional geological evolution history, and different stages of the geological processes in the Gagarin region were divided according to the active periods and stage characteristics of internal and external dynamic geological processes. [Significance] The study revealed the geological features of key areas on the far side of the moon, delving into the geological history of the Gagarin region and tentatively establishing a correlation between its geological traits and the lunar evolutionary history. [ABSTRACT FROM AUTHOR]

Archaean greenstone remnants comprising mainly metamorphosed basaltic lavas and lesser metasedimentary interlayers are components of the granite-gneiss-migmatite basement terrane of the central and northern parts of the Kruger National Park (KNP), South Africa's premier wildlife nature reserve. Most of the greenstone remnants represent extensions into the Kruger Park of better developed and exposed greenstone belts that exist beyond the borders to the west, including the Giyani and Murchison greenstone belts. Geological mapping in the national park presents challenges as exposures are poor and discontinuous, with the dense bush and wildlife adding to the difficulties. Satellite remote sensing provided an ideal solution and in this study Google Earth imagery proved to be especially helpful. The imagery provides a synoptic overview of the terrane making it possible to establish the outline of greenstone remnants irrespective of the dense bush cover. Google Earth imagery furthermore provided a preliminary impression of a hitherto unknown, yet sizeable, greenstone belt remnant in a remote area south of the Olifants River in the central section of the KNP. Referred to as the Olifants River Greenstone Belt in this study the remnant occurs as a major Type 2 interference fold resembling a mushroom-shaped diapir with a broad bulbous core fringed by laterally flattened skirts. Images are presented that illustrate various components of this imposing structure. Google Earth images furthermore display the general character of the Archaean granite-greenstone basement and the Palaeoand Mesoproterozoic intrusive dyke swarms on the northeastern flank of the Kaapvaal Craton. [ABSTRACT FROM AUTHOR]

The increasing availability of large geological datasets together with modern methods of data analysis facilitate a data science approach to geology in which inferences are drawn from geological data using automated methods based on statistics and machine learning. Such methods offer the potential for faster and less subjective interpretations of geological data than are possible from a human interpreter, but translating the understanding of a trained geologist to an algorithm is not straightforward. In this paper, we present automated workflows for detecting geological folds from map data using both unsupervised and supervised machine learning. For the unsupervised case, we use regular expression matching to identify map patterns suggestive of folds along lines crossing the map. We then use the hdbscan clustering algorithm to cluster these possible fold identifications into a smaller number of distinct folds, the number of which is not known a priori. For the supervised learning case, we use synthetic models of folds to train a convolutional neural network to identify folds using map and topographic data. We test both methods on synthetic and real datasets. [ABSTRACT FROM AUTHOR]

Crater detection is useful for research into dating a planetary surface's age and geological mapping. The high-resolution imaging camera (HiRIC) carried by the Tianwen-1 rover provides digital image model (DIM) datasets with a resolution of 0.7 m/pixel, which are suitable for detecting meter-scale craters. The existing deep-learning-based automatic crater detection algorithms require a large number of crater annotation datasets for training. However, there is currently a lack of datasets of optical images of small-sized craters. In this study, we propose a model based on the Segment Anything Model (SAM) to detect craters in Tianwen-1's landing area and perform statistical analysis. The SAM network was used to obtain a segmentation mask of the craters from the DIM images. Then non-circular filtering was used to filter out irregular craters. Finally, deduplication and removal of false positives were performed to obtain accurate circular craters, and their center's position and diameter were obtained through circular fitting analysis. We extracted 841,727 craters in total, with diameters ranging from 1.57 m to 7910.47 m. These data are useful for further Martian crater catalogs and crater datasets. Additionally, the crater size–frequency distribution (CSFD) was also analyzed, indicating that the surface ages of the Tianwen-1 landing area are ~3.25 billion years, with subsequent surface resurfacing events occurring ~1.67 billion years ago. [ABSTRACT FROM AUTHOR]

Background: Gabal Ras Abda area as a part of the Red Sea Mountain range, is characterized by inaccessible and rugged terrains. The exposed rock units are hardly followed in the field because of the rigid topography. Thus, the present work proposes and develops an integrated approach to map the exposed rock units and extract the geologic structures using satellite imagery data followed by both field and petrographic verification, saving time, efforts and cost. Results: To achieve the target, both the measured spectral signature curves with Landsat-8 and Sentinel-2A data were used to develop and create the most enhanced Band Ratios and Principal Components for lithological discrimination and mapping which were (((Band7 + Band 4)/(Band 7), (Band 2)/(Band 2 + Band 5) and (Band 5) in RGB) and ((Band 9 + Band 11 + Band 12)/(Band 1), (Band 4 − Band 2) and (Band 11/Band 6) + (Band 6) in RGB)) with Principal Component Bands ((PC1, PC2 and PC3 in RGB) and (PC3, PC2 and PC1 in RGB)), respectively. Also, georeferenced Google Earth Pro, panchromatic band of Landsat-8 and ALOS PALSAR Digital Elevation Model images were used to extract the structural lineaments. Geologic, petrographic and field structural studies were emphasized the remote sensing results, indicating that the main rock types cropped out in Ras Abda area from the oldest to the youngest are older granitoids (quartz-diorites, tonalites and granodiorites), Dokhan volcanics (andesites, rhyodacites, rhyolites and their related tuffs), younger gabbros, younger granites (monzogranites, syenogranites and alkali-feldspar granites), post-granite dykes and offshoots (acidic, microgranitic and basic types) and Phanerozoic sedimentary rocks. Also, the study emphasized that the E-W trend is the main structural trend controlling the investigated area followed by WNW-ESE and NE-SW directions. Conclusions: The results of remote sensing achieved compliance with the geologic, petrographic and structural investigation through distinctly differentiating the different rocks and extracting the lineaments, indicating the accuracy of the remote sensing results and emphasizing their importance and effective role in producing a precise and highly accurate geologic map. [ABSTRACT FROM AUTHOR]

This paper provides an insight into the structures, lithologies, and potential zones and their relationships to gold mineralisation that were investigated to decipher the controls of gold mineralisation at the Kibati Gold Prospect within the Mozambique Belt. Although the Kibati area is located within the gold mineralised zone, lithology and subsurface geological structures associated with gold mineralisation are not well studied. The available high-resolution aeromagnetic data have not yet also been analysed and interpreted to derive geological features that are useful in mineral exploration. The investigation of the structures and lithologies was accomplished through integrated interpretation of high-resolution aeromagnetic data, ground magnetic data, geological mapping, and rock sampling. Aeromagnetic and ground magnetic results reveal the presence of two structural systems, which were previously not identified that trend in NW–SE and NE–SW, with the NW–SE being the dominant control of gold mineralisation. The subsurface structure with NW–SE trending controls the mineralised fluids as a consequence of gold mineralisation in the surface lithologies. Petrography and geological mapping show that granitic gneiss, garnet-biotite quartzo-feldspathic gneiss, dolerite, and amphibolite are the main exposed outcrops where the first two identified types of gneisses, based on their protolith, were previously not specified. Based on the gold assay results, which are persistent and collinear to the structural trend of NW–SE picked out by magnetic data, two (2) potential blocks (A and B) were identified. The trend of the structure in blocks A and B when overlaid with gold anomalies indicates that most of the gold concentrations are located in block B and the highest value of gold concentrations is located in block A where gold values range from 10.19 to 19.680 g/t in block A and 0.0623 to 4.419 g/t in block B. The difference in gold values between blocks A and B is due to the variation in the degree of alteration. The integration of the results indicates that the gold mineralisation in the Kibati area is structurally controlled and concentrated in shear zones. The findings therefore, indicate that the Mozambique Belt is potential for gold mineralisation and provide a warrant for future plan for gold exploration. [ABSTRACT FROM AUTHOR]

Аbstract: The basement of Arctic Alaska–Chukotka microcontinent (AAChM) is exposed in the Velitkenai granite–metamorphic dome of Chukotka. U–Th–Pb (SIMS) geochronological study of the orthogneisses of the basement, paragneisses after Paleozoic rocks, and leucogranites of the Velitkenai massif in the central and southwestern parts of this structure was carried out. The Neoproterozoic age of basement orthogneisses (Velitkenai complex) and the Albian age of granitoids of the last stage of the Velitkenai massif were confirmed. The latter coincides with the age of migmatization of orthogneisses. The youngest zircon populations from paragneisses within the Velitkenai complex are from the Cambrian and the Silurian; single zircon crystals contain inherited cores with ages of 1.7 and 1.9 Ga. The correlation of the Neoproterozoic orthogneisses of the Velitkenai granite–metamorphic dome with similar complexes of the other AAChM regions indicates the unity of its basement. It is suggested to enter the Velitkenai metamorphic complex into the legend of the Chukotka series of the third-generation geological map sheets. [ABSTRACT FROM AUTHOR]

Amravati has been designated as the prospective youthful capital of the Indian state of Andhra Pradesh, nestled in the geologically stable southern peninsular region. Following the impactful Bhuj earthquake on 26 January 2001 measuring 7.6 Mw on the Richter scale, which resulted in substantial destruction, there has been a heightened curiosity in seismic microzonation research throughout India, encompassing Andhra Pradesh. This study is specifically cantered on evaluating the seismic activity and microzonation of Amaravati, employing a multifaceted seismic hazard assessment methodology. The exploration encompasses three distinct phases. Firstly, site characterization involves regional geological, geomorphological, and geotechnical analysis. Secondly, local site effects and resonance frequencies are assessed using DEEPSOIL software, providing amplification factors through a one-dimensional linear approach. In the third stage, liquefaction hazard analysis and liquefaction potential index are evaluated using the simplified procedure suggested by Seed and Idriss. Microzonation results are presented through nine themes: which includes geological mapping, geomorphology, geotechnical observations, shear wave velocity distribution, seismotectonic set-up, rock depth, amplification, peak ground acceleration, and liquefaction susceptibility mapping. The thematic mapping divides the Amaravati region into three zones: susceptible, partially susceptible, and not susceptible. This comprehensive study enhances understanding of seismic hazards in the Amaravati capital region, aiding in informed urban planning and disaster mitigation. [ABSTRACT FROM AUTHOR]

It is evident that the Yangtze Craton was involved in the formation and breakup of the Columbia supercontinent. However, due to the scarcity of Mesoproterozoic geological records and reliable paleomagnetic data, little is known about the timing, paleogeographic position, and geological processes of the Yangtze Craton. We conducted detailed geological mapping, petrographic, geochemical, and in situ zircon U-Pb and Lu-Hf isotopic investigations on newly recognized Mesoproterozoic quartz syenite and monzogranite in the Dabie orogen, northern Yangtze Craton. The results show that the quartz syenite and the monzogranite were emplaced at 1369 ± 12 Ma and 1372 ± 5 Ma, respectively. Both rocks are high in total alkali (K2O + Na2O) content and FeOt/(FeOt + MgO), with elevated diagnostic 10,000*Ga/Al ratios and Zr + Nb + Ce + Y concentrations, and enrichment in light rare earth elements. They are also depleted in heavy rare earth elements with significant negative Eu anomalies but remarkably low Sr, Cr, and Ni contents. These compositions define affinity to A1-type granite. In addition, the quartz syenite displays variable zircon Hf and homogeneous whole-rock Nd isotopic compositions with positive εHf(t) values of +0.7 to +5.7 (average +2.4) and εNd(t) values of -0.1 to +2.5 (average +1.0). In contrast, the monzogranite has homogeneous zircon Hf and whole-rock Nd isotopic compositions with negative εHf(t) values of -5.7 to -2.6 (average -4.8) and εNd(t) values of -3.5 to -1.5 (average -2.2). We propose that the quartz syenite was likely generated by the partial melting of juvenile, crust-derived melt with involvement of minor mantle-derived material, while the monzogranite was likely derived from the partial melting of ancient crust in an extensional tectonic regime (e.g., continental rift). Based on the newly recognized ca. 1.37 Ga granitic magmatism and previously reported magmatic events, we argue that the mid-Mesoproterozoic (ca. 1.37 Ga) magmatism in the Yangtze Craton occurred in response to the breakup of Columbia, and represents the separation of the Yangtze Craton from Columbia. Furthermore, according to comparable magmatic and sedimentary events, we propose that the Yangtze Craton, along with central Hainan Island, may have been linked to northwestern Laurentia, southwestern Siberia, and northeastern Australia during 1.6-1.4 Ga. [ABSTRACT FROM AUTHOR]

The Cenozoic growth of the Tibetan Plateau and the distribution of deformation across it are a consequence of India-Asia collision and continued convergence, which have implications for studies of continental tectonics. The spatio-temporal development of Cenozoic deformation along the northern margin of the plateau is an important issue that can be better understood by testing various models of plateau growth. The northern Tibetan Plateau is bounded by the Cenozoic Qilian Shan thrust belt and the Haiyuan leftslip fault. We conducted geologic mapping, field observations, electron spin resonance (ESR) dating, and apatite (U-Th)/He (AHe) and apatite fission-track (AFT) analysis in the Qilian Shan thrust belt to improve our understanding of the timing of brittle faulting and range exhumation in the northern Tibetan Plateau. We document the first direct age constraints for Oligocene deformation within the central Qilian Shan via ESR dating, which correlates with AHe-AFT cooling ages in adjacent ranges. We demonstrate that the Qilian Shan thrust belt experienced a two-phase growth history, including Eocene-Oligocene fault-related uplift shortly after the India-Asia convergence, and mid-Miocene regional overprinting deformation that reactivated the proximal thrust faults. This deformational pattern suggests that the Qilian Shan thrust belt has experienced out-of-sequence development since the Eocene-Oligocene and has persisted as the stationary northeastern boundary of the Himalayan-Tibetan Orogen throughout the Cenozoic. The Paleozoic Qilian suture systems acted as a pre-existing weakness and played a decisive role in controlling the lithospheric rheology, which therefore impacted the timing, pattern, and strain distribution of Cenozoic deformation across the northern Tibetan Plateau. [ABSTRACT FROM AUTHOR]