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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]

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]

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]

At perhaps the coarsest scale of consideration, the rock cycle operates through fluxes associated with tectonic uplift and erosion, which are generally balanced by subsidence/subduction and the burial of mineral materials that leads to volumetric balance among the principal rock reservoirs. At Earth's surface, net rates of transfer are manifest as the reduction of areas of older rocks during erosional destruction as well as during burial by younger units. Because exposure of continental crust comprises some finite space, decrease of older rock area by erosion and/or burial must be largely balanced by an increase in area of new sedimentary and volcanic successions. Here, we examine relations between the lateral extents of rock units exposed across North America-their lithology, elevation, and the age of formation-to determine rates of geologic "repaving" that are recorded in the age and area of rocks making up the surface of the continent. Moreover, because deposition occurs at lower elevations, one might expect that subsequent episodes of uplift and/or burial would serve to increase the average elevation of currently exposed sedimentary lithosomes. Because plutonic and metamorphic rocks form at depth and are only exposed along orogenic belts and across shields after extended intervals of uplift and/or erosion, one might expect basement rocks to be initially exposed at higher elevations, and that subsequent erosion would decrease elevation with increasing age. Therefore, processes giving rise to associations between outcrop lithology, extent, and elevation may serve as measures of continentscale rates of rock cycling. We combine data from the 1 arc-minute global relief model with data from the Geological Society of America's 2005 Geologic Map of North America to assess the actuality and significance of first-order relations among the lithologies, areas, ages, and elevations of rock bodies now exposed across the North American continent and how these may shed light on deep-time rates of rock cycling. Areas of the 23,642 mapped North American lithosomes make up a lognormal frequency distribution (mode = 121 km²). This distribution reflects both natural (lateral extents of individual map units must be limited in space) and anthropogenic (cartographers must render map units within limited range of sizes) causes. Contiguous, lateral associations of the major rock types suggest that the spatial occurrence of volcanic and sedimentary rock bodies is largely independent of the proximity of other rock types, but exposures of plutonic and metamorphic lithosomes are intimately associated in space and thus comprise the "crystalline basement" exposed in cores of younger orogens and across the Canadian Shield. Unlike sedimentary and volcanic rocks that "attain their age" when formed at Earth's surface, plutonic and metamorphic units are "born" at depth and therefore must have reached some antiquity prior to first exposure. As a result, the ages of volcanic and sedimentary exposures span the full range of ages represented by all lithologies, while those of plutonic and metamorphic suites are more abbreviated and older. Median ages of North American volcanic, sedimentary, plutonic, and metamorphic exposures are 482 Ma, 306 Ma, 1695 Ma, and 2467 Ma, respectively. Although the areal extent of sedimentary rock decreases with increasing age, elevation increases. This change is interpreted as reflecting progressive tectonic uplift from initial accumulation at lower elevations. In contrast, the surfaces of exposed volcanic, plutonic, and metamorphic lithosomes become lower in elevation with increasing age. This change reflects both the erosional lowering of lithosome surfaces as well as the progressive exhumation of larger areas of crystalline basement. Exposed rock area exhibits a power law decrease with increasing age. This change reflects the progressive destruction of older units and their burial by younger units. A simple "repaving" model in which 0.8% area is uplifted and eroded per million years is in good agreement with observed relations of map age versus area, the rate of which is equivalent to the resurfacing of the North American continent every 63 m.y. or -56 times over the past 3.5 Ga. The rate of decrease in map area of exposed rocks with increasing age evident in both geologic map data and repaving models is about three times the rate of decrease in total sediment volume as determined from stratigraphic data and repaving models. The decrease in the areas of exposed rock units is primarily the result of burial by younger units rather than erosive destruction. [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]

Bali island is part of the Sunda volcanic arc with an active volcano at its center. The Buyan-Bratan caldera, the Batur volcano, and the Agung volcano are active volcanoes aligned from the west to the east of the island of Bali. The activity and age of volcanoes progress eastward. Therefore, the physical properties and conditions of each body of magma beneath the volcanoes on the island of Bali requires investigation. Ground magnetic measurements were carried out throughout the island and integrated with the Bouguer anomaly map. Hand samples were taken that represented each lithology of Bali Island. Furthermore, magnetic susceptibility and density measurements were carried out, which were used as initial data for generating magnetic and gravity models. Apart from that, geological maps and previous geological and geophysical research in the Bali Island area were also used as supporting data to create magnetic and gravity models. Magnetic and gravity modeling shows a carbonate rock formation in Bali Island's southern volcanic area, surrounded by a graben up to 6 km deep and covered by volcanic deposits. Furthermore, magnetic and gravity models indicate an intrusive rock between Agung and Batur volcanoes as well as shallow and deep magma chambers beneath the Buyan-Bratan Caldera, Agung, and Batur volcanoes. The magnetic susceptibility and density differences from the magnetic and gravity models in this study are one way to trace the eastward shift in volcanic activity on Bali Island. These findings will contribute to better understanding the volcanic processes and the migration of volcanic centers, which can help volcanic and earthquake hazard mitigation. [ABSTRACT FROM AUTHOR]

During comprehensive regional prospecting evaluation and delineation of a prospecting target area, various types of data, including geological, geophysical, geochemical, and remote sensing, are usually integrated and visualized in a unified spatial environment, making it convenient for researchers to identify mineralization. To maximize the precision of spatial boundaries, the maps traditionally used in prospecting are predominantly in vector formats. However, with the rapid development of modern real-time 3D graphics and computer cartography technology, raster maps can now provide richer detail representation compared to traditional vector maps while still meeting the precision requirements. In this paper, we present a new GPU-based 3D visualization method for spatial data, specifically, two types of bitmap-based maps called dynamic geochemical maps (DGMs) and interactive geological maps (IGMs). A novel software system implementing this method was developed and has been applied in the exploration of the Zhunuo ore district, Tibet, showing large advantages over traditional vector maps. [ABSTRACT FROM AUTHOR]

Remote sensing satellite imagery consistently provides valuable and frequent information, enabling the exploration of mineral resources across immense, remote and harsh domains. Recent developments in spaceborne hyperspectral remote sensing have opened avenues to support diverse remote sensing applications, particularly in the realm of mineral exploration. This study evaluates the capabilities of the PRecursore IperSpettrale della Missione Applicativa (PRISMA) hyperspectral satellite data for mapping alteration minerals using the Matched Filtering Unmixing (MFU) approach in the Sar-e-châh-e-shur, Birjand, Iran. Minerals such as richterite, augite, psilomelane, ilmenite, kaolinite, smectite, mirabilite, muscovite, and chlorite were identified using the vertex component analysis (VCA) technique. Subsequently, alteration mineral maps of the study area were generated using a matched filtering technique. Additionally, through the integration of X-ray diffraction (XRD) analysis, thin section examination, geochemical study of stream sediments, and interpretation of geological maps, potential alteration mineralization zones were delineated in the study area. Ultimately, the validation process, which included comparing the maps with the findings derived from the PRISMA remote sensing study, was conducted using the normal score equation. Thus, our results yielded a normalized score of 3.42 out of 4, signifying an 85.71% agreement with the regional geological characteristics of the study area. The results of this investigation highlight the substantial potential of the PRISMA dataset for systematic alteration mineral mapping and consequent exploration of ore minerals, specifically in challenging and inaccessible terrains. [ABSTRACT FROM AUTHOR]

This article presents an innovative application of kHz regime μLIBS – Laser-Induced Breakdown Spectroscopy for generating detailed compositional maps of geological samples. The method effectively covers large areas (tens of cm2) rapidly while maintaining high lateral resolution (below 20 μm), producing some of the most extensive LIBS compositional images to date, with a size of 10 million pixels. Employing elemental-based images, we developed a direct methodology for mineral phase identification through mask-creation operations and logical relationships. This approach was successfully applied to reconstruct the mineralogical map of a Li-ore from the west-European Variscan belt, identifying 14 different mineral phases, including economically valuable ones like lepidolite, cassiterite, and columbite-group minerals. Furthermore, based on the reverse normative calculation, the chemical composition of the sample was calculated from the mineral phases previously obtained. The kHz μLIBS approach marks a significant advancement in elemental and phase imaging, especially pertinent to geological applications, providing comprehensive petro-geochemical insights, essential for a fast geological characterization. [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]

Jbel Ougnat is the eastern extension of the eastern belt of the Anti-Atlas. This article focuses on a geophysical study using high-resolution aeromagnetic data covering the Jbel Ougnat area. These data were first filtered using several geophysical processing methods: reduction to the pole, horizontal gradient (HG), and Euler deconvolution (ED). They were, then, analysed and interpreted in the light of the geological background. The HG is used to detect magnetic lineaments, whereas the ED is used to estimate the location and depth of magnetic sources. The results obtained were compared with the geological maps and field survey data. The orientations of the lineaments, extracted from the HG map, are mainly trending NE-SW and NNW-SSE to N-S and NW-SE. The fieldwork helped to identify the mineralised features of these lineaments. The combination of these results with the depth values obtained from Euler solutions shows that these orientations are associated with several tectonic events, recorded by the area during its entire geological history. [ABSTRACT FROM AUTHOR]

The field of planetary mapping and cartography builds almost exclusively on remote-sensing data and can be defined by three distinct concepts: systematic imaging as performed through spacecraft surveying, reference mapping as performed through the compilation of reference maps, i.e., regional to global image and topographic maps, and thematic mapping, which aims at abstracting and contextualizing spatial information to generate complex thematic maps, such as geologic or geomorphologic maps. While thematic mapping represents the highest form of abstraction of information that is provided through systematic mapping, thematic mapping also provides scientific reasoning in support of systematic mapping and exploration through spatially contextualized knowledge. For the development of knowledge, it is paramount to manage and exploit the value of thematic maps as research products, and to design a reliable and transparent development process from the beginning of the mapping phase as there is almost no validation for thematic maps. A key element in accomplishing these objectives is well-designed structures and metadata which are maintained within spatial data infrastructures (SDI) and shared as a coordinated process in research data management through data models. In this contribution, we focus on the need to transfer planetary thematic maps into findable, accessible, interoperable, reusable (FAIR), as well as transparent research data assets to facilitate improved knowledge extraction and also to compensate for limitations caused by the lack of conventional validation options. We review the current status of planetary thematic mapping, and we discuss the principles and roles of mappers and publishers in the process of creating and stewarding digital planetary maps and associated data products. We then present and discuss a set of recommendations that are closely tied to the FAIR concepts in research data management to accomplish such tasks. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicle (UAV)-based geological mapping is significant for understanding the geological structure in the high-steep slopes, but the images obtained in these areas are inevitably influenced by the backlit effect because of the undulating terrain and the viewpoint change of the camera mounted on the UAV. To handle this concern, a novel backlit image restoration method is proposed that takes the real-world application into account and addresses the color distortion issue existing in backlit images captured in high-steep slope scenes. Specifically, there are two main steps in the proposed method, which consist of the backlit removal and the color and detail enhancement. The backlit removal first eliminates the backlit effect using the Retinex strategy, and then the color and detail enhancement step improves the image color and sharpness. The author designs extensive comparison experiments from multiple angles and applies the proposed method to different engineering applications. The experimental results show that the proposed method has potential compared to other main-stream methods both in qualitative visual effects and universal quantitative evaluation metrics. The backlit images processed by the proposed method are significantly improved by the process of feature key point matching, which is very conducive to the fine construction of 3D geological models of the high-steep slope. [ABSTRACT FROM AUTHOR]

The surface temperature of the snow cover is a key variable, as it provides information about the current state of the snowpack, helps predict its future evolution, and enhances estimations of the snow water equivalent. Although satellites are often used to measure surface temperature and despite the difficulty to retrieve accurate surface temperature from space, calibration-validation datasets over snow-covered areas are scarce. We present a dataset of extensive measurements of the radiative surface temperature of snow acquired with an uncooled Thermal Infrared (TIR) camera. The set accuracy goal is 0.7 K, which is the radiometric accuracy of the TIR sensor of the future CNES/ISRO TRISHNA mission. TIR images have been acquired over two winter seasons, November 2021 to May 2022 and February to May 2023 at the Col du Lautaret, 2057 m a.s.l. in the French Alps. During the first season, the camera operated in the off-the-shelf configuration, with a rough thermal regulation (7 °C–39 °C). An improved setup with a stabilized internal temperature was developed for the second campaign, and comprehensive laboratory experiments were carried out in order to characterize the physical properties of the TIR camera components and its calibration. A thorough processing including radiometric processing, orthorectification and a filter for poor visibility conditions due to fog or snowfall have been performed. The result is two winter season timeseries of 130,019 maps of the surface radiative temperature of snow with meter-scale resolution over an area of 0.5 km2. The validation is performed against precision TIR radiometers. We found an absolute accuracy (MAE) of 1.28 K during winter 2021–2022 and 0.67 K for spring 2023. The efforts to stabilize the internal temperature of the TIR camera therefore led to a notable improvement of the accuracy. Although some uncertainties persist, particularly the temperature overestimation during melt, this dataset represents a major advance in the capacity to monitor and map surface temperature in mountainous areas, and to calibrate-validate satellite measurements over snow-covered areas of complex topography. The complete dataset is at https://doi.org/10.57932/d4e105c4-b6a3-4520-b174-3913fbb20cb7 (Arioli et al., 2024a) and https://doi.org/10.57932/8c782a49-c992-47af-89bb-2684093e2c65 (Arioli et al., 2024b). [ABSTRACT FROM AUTHOR]

The creation of accurate elevation models (topography) from stereo images are critical for a large variety of geospatial activities, including the production of digital orthomosaics, change detection, landing site analysis, geologic mapping, rover traverse planning, and spectral analysis. The United Stated Geological Survey, Astrogeology Science Center, continues to transition the supported planetary sensor models to the Community Sensor Model (CSM) standard. This paper describes the current state of use for this photogrammetric standard, supported sensor model types, and qualitatively compares derived topography between SOCET SET and SOCET GXP (®BAE Systems) using HiRISE stereo images of Mars. Our transition to the CSM standard will ensure an uninterrupted capability to make these valuable products for Mars and many other extraterrestrial planets and moons. [ABSTRACT FROM AUTHOR]

This study investigates the application of hyperspectral image space–spectral fusion technology in lithologic classification, using data from China's GF-5 and Europe's Sentinel-2A. The research focuses on the southern region of Tuanjie Peak in the Western Kunlun Range, comparing five space–spectral fusion methods: GSA, SFIM, CNMF, HySure, and NonRegSRNet. To comprehensively evaluate the effectiveness and applicability of these fusion methods, the study conducts a comprehensive assessment from three aspects: evaluation of fusion effects, lithologic classification experiments, and field validation. In the evaluation of fusion effects, the study uses an index analysis and comparison of spectral curves before and after fusion, concluding that the GSA fusion method performs the best. For lithologic classification, the Random Forest (RF) classification method is used, training with both area and point samples. The classification results from area sample training show significantly higher overall accuracy compared to point samples, aligning well with 1:50,000 scale geological maps. In field validation, the study employs on-site verification combined with microscopic identification and comparison of images with actual spectral fusion, finding that the classification results for the five lithologies are essentially consistent with field validation results. The "GSA+RF" method combination established in this paper, based on data from GF-5 and Sentinel-2A satellites, can provide technical support for lithological classification in similar high-altitude regions. [ABSTRACT FROM AUTHOR]

Geological maps of Earth typically incorporate field observations of rock lithology, structure, composition, and more. In contrast, conventional planetary geological maps are often made using primarily qualitative morphostratigraphic remote sensing observations of planetary surfaces. However, it is possible to define independent quantitative spectral units (SUs) of planetary surfaces, which potentially contain information about surface composition, grain size, and space weathering exposure. Here, we demonstrate a generic method to combine independently derived geomorphic and SUs, using the Rachmaninoff basin, Mercury, as an example to create a new geostratigraphic map. From this geostratigraphic map, we can infer some compositional differences within geomorphic units, which clarifies and elaborates on the geological evolution of the region. Plain Language Summary: Geological maps of rocks on Earth include information about what landforms the rocks exhibit, what they are made from, their orientation, and more. Many such details require ground observations, but these are generally not available for planetary geological maps, which rely on spacecraft data. Spacecraft images can be used to map planetary surface textures (geomorphology), but they can also be used to measure surfaces' responses to light (reflectance or emission spectra), which contain information about what the surface rocks are made from, their physical properties (e.g., grain size, roughness, porosity), and how long they have been exposed at the surface. We have combined earlier, independent geomorphic and spectral maps of the Rachmaninoff impact basin on Mercury to create a new "geostratigraphic" map that is more like a geological map that could be made of Earth. The new map highlights places that in the original geomorphic map would have been mapped all as a single unit, but are divisible based on spectral variations, attributable to differences in what the rocks are made from. This allows us to reconstruct a more detailed geological history of the region. Our method can be applied to other regions on Mercury and to other planetary surfaces. Key Points: We combine independent morphostratigraphic and spectral units of Rachmaninoff basin to create geostratigraphic unitsGeostratigraphic units can distinguish volcanic plains and impact melt in contact with each otherGeostratigraphic units imply a wider distribution of (LRM‐composition) impact melt than previously recognized [ABSTRACT FROM AUTHOR]

Integrating a 3D geological model into the virtual Earth environment enables the display of the geological model on a larger scale, making the surrounding terrain and landform more intuitive, and improving the accuracy of geological research. Because the section analysis of 3D geological model can clearly show the geological structure and attribute information on a section, it is a popular analysis method for geologists. However, the existing methods based on Boolean operations have high requirements on the topological relationship of the model, and their efficiency and accuracy are not ideal when faced with complex 3D geological models. Meanwhile, traditional rendering-based methods can only obtain pixel-level sectional results, making measurement difficult. This paper proposes a cutting analysis algorithm for 3D geological model in virtual earth environment. This method utilizes hierarchical bounding volume (BVH) and ray intersection algorithm to extract formation boundary data, avoiding complex Boolean operations and improving the efficiency of section analysis. Furthermore, using these data to draw measurable geological section maps effectively solves the problem that the section results cannot be measured. This method can be used to quickly and effectively obtain a section diagram the conforms to the standard diagram legend, which can be directly used in the preparation of geological analysis reports. The feasibility of this method is verified by taking the section analysis of a complex 3D geological model in a certain area as an example. [ABSTRACT FROM AUTHOR]

Field data from recent geological mapping over a major part of the north-central Scandinavian Caledonides combined with published information give a detailed view of early Cambrian basin successions, comprising the Gärdsjön formation (Gf; Jämtland supergroup) in the Lower Allochthon and autochthonous equivalents (Dividal Group). The Gf comprises ten units of sandstone and siltstone or mudstone (Gf I—X, > 300 m thick). Green siltstones with red layers (Gf VI, c. 521 to 519 Ma) and green–grey siltstones at the top (Gf X, c. 516.5 to 513.5 Ma) are regional key horizons. Gf V, VI, VII, IX, and X deposition may be related to eustatic events. Restoration of Caledonian shortening reveals a major "Hornavan-Vattudal basin" (HVB; > 330 km NW–SE, > 400 km NE-SW) between the Grong–Olden culmination in the S and the Akkajaure–Tysfjord culmination in the N. Published zircon ages imply the latter separated the HVB from those shed from the Timan orogen in the N. The eastern basin margin straddles the present Caledonian erosional margin. Basement highs identified here within the Nasafjället, Bångonåive, and Børgefjellet "basement" windows define the western margin. They separate the HVB from the outer shelf towards the Iapetus Ocean in the W. The onset of sedimentation is time-related with E–W extension at c. 544–534 Ma. NNE–SSW-directed extension occurs after c. 518 Ma, perhaps related with Timan late-orogenic extension. The HVB is distinctly younger (c. 535–513.5 Ma) than Rodinia break-up and Iapetus ocean formation (> 550 Ma), comparable with post-rift basins in inner parts of modern passive margins. [ABSTRACT FROM AUTHOR]

In the present study, we have integrated the spectral anomaly map derived from airborne visible-infrared imaging spectrometer-next generation (AVIRIS-NG) data and residual ground geophysical anomaly maps (gravity and magnetic) for identifying the mafic cumulates and chromitites in the Sittampundi Layered-Complex (SLC), Tamil Nadu, India. A spectral map of chromite bearing mafic cumulates was prepared by implementing the matched filtering (MF) algorithm on the selected spectral bands of AVIRIS-NG data using the mixed image spectra of mafic cumulate and chromitite as an end member. A low pass filter was applied in the spectral map to extract the clusters of coherently distributed spectrally anomalous pixels representing the surface exposure of mafic cumulates. Concurrently, the ground gravity and magnetic data were processed for deriving the residual gravity and magnetic anomaly maps. Subsequently, an integration of spectral map, residual gravity, and magnetic anomaly maps was attempted using the support vector machine (SVM) algorithm to identify the potential sites of chromitite occurrence. Results were verified using the geological map and the field data on surface exposures of mafic cumulates. This research demonstrates that integration of remote sensing data and geophysical anomaly maps has immense potential to detect the surface distribution of chromite bearing mafic cumulates in the layered complex and the same methods can be replicated for carrying out mineral prospecting in the other parts of the world. [ABSTRACT FROM AUTHOR]

Eugène Rodolphe Faribault proved to be a very good choice as a geologist for the Geological Survey of Canada, after his appointment on July 1, 1883. His career spanned fifty years, time mostly committed to mapping the southwestern half of Nova Scotia, concentrated on the slate and quartzite of the Meguma Supergroup in which gold mining was taking place. In his words, he was, "a specialist on geological maps and structural geology of gold mines in Nova Scotia." Dozens of his meticulously prepared maps of over sixty gold districts have stood the test of time for accuracy. A popular figure in the field, Faribault made frequent trips to operating mines. He early recognized the existence, in some districts, of extensive bodies of low-grade ore. He emphasized too, the similarities between the 'saddle reef' deposits mined in the Bendigo fields of Australia and the auriferous veins of the Meguma formations. His 'pay-zone' theory held that near-surface mineable ore in Nova Scotia gold mines should continue at depth, provided the same structural conditions persisted. However, for various reasons his theory received a mixed reception. Back in Ottawa at the GSC offices, Faribault was a highly respected figure among fellow workers and supervisors alike, and across all departments. His quiet charisma and friendly nature, complemented by professional expertise, won him accolades as an ambassador well beyond the workplace. For his excellence in a young developing science, Faribault thoroughly earned the epithet, "The Grand Old Man of Nova Scotian Geology". [ABSTRACT FROM AUTHOR]

The paper presents a study of the anisotropic properties of the karst surface through the use of semivariograms. Karst is formed by hydrogeological and tectonic deformations that determine the surface and subsurface characteristics of the area. Among the most prominent surface features are dolines, which generally form in a linear direction. Semivariograms can be used to determine both the preferred direction of anisotropy and the degree of anisotropy. The surface exhibits the greatest elevation variability in the direction of the most diverse terrain, corresponding to dolines. The results, based on the eight karst areas studied, show that it is possible to detect and, more importantly, quantify anisotropy in all karst areas, although in some cases it is impossible or difficult to detect visually. The directions of the semivariograms agree very well with those obtained from the visual inspection of the maps, as well as with the orientations of the main faults. The method is therefore very useful for quantitative determination of anisotropy and its interpretation could be greatly improved by using the detailed structural geological maps of the karst. [ABSTRACT FROM AUTHOR]

This study establishes the structure of the Tisserfine basin, located in the eastern Moroccan High Atlas, through an integrated interpretation of geophysical data. Several types of data were integrated in this work: a gravity map, 243 vertical electrical soundings (VES), a seismic reflection profile; logs of 10 boreholes, geological maps, and field structural measurements. The gravity map shows a succession of lows and highs-oriented WSW-ENE, paralleling the regional structures (synclines and anticlines). Gravity lows are correlated with Triassic evaporites (mostly clays) that were uplifted into high elevation areas (anticlines). Gravity highs correspond to the accumulation of limestones, sandstones, and marls in synclines. A multiscale analysis of gravimetric lineaments shows the main faults bordering the anticlines and synclines. The seismic reflection profile indicates that the Tisserfine syncline is affected by several faults; the Mesozoic formations in the axis of the syncline exceed a depth of 3000 m, and that the anticlines (corresponding to topographic highs) present very high dips (69–87°). The results of 2D resistivity models are in good agreement with geological data and reveal several faults. The models exhibit a conductive layer (marls, 800 m-thick), with intercalations of highly resistive levels inferred to be sandstones. The basement is characterized by very high resistivity values, matching limestones or dolostones. The hydrogeological units consist of two unconfined and three confined aquifers. The piezometric outline shows that the groundwater flows converge towards the Tisserfine wadi with a direction flow to the east. The presence of water throughout the year in several places at the Tisserfine and Zouzfana wadis (e.g. Dfilia (Aghlal) springs) represents the drainage of an unconfined aquifer. [ABSTRACT FROM AUTHOR]

This paper presents a sequentially restored cross-section of the Organyà and Montsec minibasins based on geological mapping, new field observations and available borehole data. The main objective was to describe the geometry and evolution of both basins in terms of salt tectonics and minibasin mobility. To this end, a comprehensive palaeomagnetic database has been used to constrain vertical-axis rotations potentially related to minibasin translation and pivoting. The Organyà minibasin constitutes an asymmetric depocentre formed during the Upper Jurassic-Lower Cretaceous by translation above a southerly inclined salt layer. Salt evacuation and minibasin touchdown induced salt accumulation on the northern side of the basin that culminated in the development of the major Santa Fe unconformity during the late Albian--early Cenomanian. Indicative of salt quiescence is the following isopachous Cenomanian to lower Santonian sequence Salt tectonics resumed during the late Santonian--Palaeocene, with the Montsec minibasin downbuilding coinciding with the onset of Pyrenean convergence. Changes of the base-salt topography reflects regional-scale geodynamic processes. The acceleration of crustal thinning in the North Pyrenean zone during the late Albian-early Cenomanian favoured uplift in the Axial Zone, increasing slope and triggering salt mobilization in the Southern Pyrenees. Likewise, the onset of contraction renewed the downslope gliding of the Organyà and Montsec minbasins, and supports the idea that the early stages of basin inversion were governed by gravity tectonics. The kinematic reconstruction suggests that the more that 30° counterclockwise vertical axis rotation records pivoting during the suprasalt translation of the Organyà minibasin rather than solely the Iberian microplate rotation. [ABSTRACT FROM AUTHOR]

A theory about a young, evolving "stealth ocean" under the ancient-looking surface of Mimas, the moon of Saturn, triggered us to revisit the icy satellite and develop a revised geological map based on Cassini images. The re-mapping of Mimas's surface aimed to fill the decades-long gap that grew since the publication of the first Voyager image-based pioneering map, and it provided an up-to-date synthetic interpretation of revised and newly discovered features. Despite the map being in its early stage of introduction, it already showed some key features that may play significant roles in the reconstruction of Mimas's (surface) evolution. The Herschel crater, formed by a global-scale impact, undoubtedly left additional marks, including fault scarps, stair-step faults, and post-impact surface transformation, through mass movements around the crater wall and the peak. Smaller craters left various scars on the surface, including asymmetric craters, whose morphology and allocation we used to reconstruct the regional topographic changes on the surface of Mimas. In addition to the impact-related features, which dominated the surface of the icy satellite, groups of weak, quasi-parallel running linear features, such as undifferentiated lineaments, grooves/through, and ridges, were also observed. The appearance and pattern of those lineaments overlapped with the allocation of various modeled global nonlinear tidal dissipations, supporting the existence of theoretical subsurface stealth oceans. [ABSTRACT FROM AUTHOR]

New, detailed geological/structural mapping and field-based structural analysis were carried out to investigate the deformation pattern of well-preserved high-pressure rocks of the Blueschist Unit exposed in SE Syros (Cyclades, Greece). Geological mapping revealed the occurrence of extensive alternations between different rock groups, as well as interfingering patterns in map-scale that are possibly the result of folding. The earlier ductile deformation phase recognized in the mapped area is associated with the development of a penetrative foliation, which was formed at eclogite/blueschist-facies conditions under peak metamorphism. The subsequent main deformation phase occurred under blueschist facies conditions synchronous with the early stages of exhumation of the high-pressure rocks. This phase is mainly associated with the formation of WNW-trending folds and a pervasive axial planar foliation linked with ESE-directed shearing. The main deformation ceased under blueschist-facies conditions, and exhumation of the rocks to greenschist-facies conditions took place under very weak and localized deformation. Greenschist retrogression observed in the southwestern part of the mapped area seems to be controlled by fluids, rather than by intense deformation and formation of major syn-greenschist shear zones. [ABSTRACT FROM AUTHOR]

Macrostrat is a platform for deep‐time geoscientific research that integrates stratigraphic columns and geologic maps into a digital description of the crust. The database and supporting software track crustal evolution and provide location‐based geological information to geoscience end users. Macrostrat houses multiple scales of mapping and stratigraphic data, from continent‐ and basin level summaries to single quadrangles and measured sections. Currently, Macrostrat's primary data holdings consist of regional stratigraphic columns with a spatial footprint weighted heavily to North America. While the data are of sufficient scale and resolution to generate insights about Earth evolution, increasing resolution and expanding spatial coverage will allow a new generation of scientific and interpretive uses. The next phase of Macrostrat's development will increase the detail and complexity of Macrostrat's multiscale data holdings, largely by engaging a wider range of geoscientists in entering stratigraphic data. To support broad collaboration, we are building new web‐based software to assemble and visualize regional stratigraphic sequences, refine multiple working age models, and compose regional records from measured stratigraphic sections. These tools will allow Macrostrat to draw on the expertise of a wide range of geoscience workers and grow a dataset with global relevance and a variety of end uses. New capabilities will pave the way to processes for submission, review, coordination, and assimilation of community‐contributed stratigraphic datasets. Digital compilation of geological maps and columns requires substantial effort, and well‐designed systems for distributing this work in the geoscience community will allow Macrostrat to build more adaptable and scientifically relevant products. [ABSTRACT FROM AUTHOR]

El Negrillar volcanic field has the largest extent and erupted volume (~ 6.8 km3 DRE) of all the monogenetic centers of the Andean Central Volcanic Zone (CVZ). The volcanic field comprises 51 eruptive centers and 98 lava flows distributed in three clusters: Northern El Negrillar (NEN), Central El Negrillar (CEN), and Southern El Negrillar (SEN). Here, we present a geological map of El Negrillar, with detail of effusive and explosive volcanic deposits not previously mapped in the southern sector of the CEN and SEN clusters. Ten samples of El Negrillar's deposits associated with effusive and phreatomagmatic activity were dated using 40Ar/39Ar geochronology, establishing, along with previously published dates, a geochronological characterization of the development of El Negrillar's monogenetic field. The collected age data yields a range of 0.982 ± 0.008 to 0.141 ± 0.072 Ma, compared to previously published K–Ar ages for the same deposits range from < 1.5 Ma to 0.6 ± 0.4 Ma. The new ages presented here indicate that the effusive activity at El Negrillar (NEN, CEN, and SEN), and the phreatomagmatic activity in the CEN (dated for first time) occurred quasi-simultaneously (within error). The end of the volcanic activity within the monogenetic field occurred in the eastern sector of the CEN at 0.141 ± 0.072 Ma, which represents the youngest eruption ages of El Negrillar. If these new ages are revisited within the regional context of the SW sector of the Altiplano-Puna Volcanic Complex (APVC), the monogenetic volcanoes appear to be the result of a migration of mafic vents along a southwest-northeast trend, as shown by their age variation from the oldest to the youngest volcanic center: Morro Punta Negra, La Negrillar, El Negrillar, Tilocálar Sur, Tilocálar Norte, Cerro Tujle, El País, Puntas Negras, La Albóndiga Grande, and Cerro Overo. These results highlight the structural control on the emplacement of monogenetic mafic volcanism in the APVC. [ABSTRACT FROM AUTHOR]

Parkinson, F.; Douglas, K.; Li, Z.; Meijer, A.; Stacey, C.D.; Kung, R., and Podhorodeski, A., 2024. A generalized semiautomated method for seabed geology classification using multibeam data and maximum likelihood classification. Journal of Coastal Research, 40(1), 1–16. Charlotte (North Carolina), ISSN 0749-0208. This paper presents a GIS-based model to perform semiautomated seabed classification that can act as a first-pass, pseudoclassified surficial geological map. The user can then edit the output into a finalized map in less time than by manual classification. The model uses maximum likelihood classification with unsupervised classification through iterative self-organizing clusters. This model is fully contained within the ArcGIS software suite as a ModelBuilder workflow composed of geoprocessing tools and Python script tools. Model inputs tested include different combinations of multibeam echosounder–derived data: slope, backscatter, and terrain ruggedness. Furthermore, to test the assumption of Gaussian distribution of input data required for maximum likelihood classification, Box–Cox power transformations were applied to slope and backscatter data and were used as model inputs. To illustrate the performance of the model, two locations are highlighted as case studies: Milbanke Sound and Spiller Channel, located on the central coast of British Columbia, Canada. Association between model outputs and ground-truth classes was generally weak to moderate when measured using Cramér's V association scores. Overall, the slope and backscatter parameter model had the highest scores of association. Results from an overlay analysis comparing model outputs with user-confirmed polygons show that the slope and backscatter model performs best in regions with distinct changes in the hardness of sediments but that in fjord regions dominated geologically by steeper bathymetric change, the slope parameter model may perform better. However, all model outputs had difficulty delineating bedrock units. The model has the flexibility to identify certain seabed habitat features as well, including glass sponge reefs—biologically active bioherms that have led to marine protected area designations in other areas of British Columbia. [ABSTRACT FROM AUTHOR]

Detailed geologic mapping (639 field stations in ~700 km2) and a ~50 km-long gravity survey (142 stations) in the western Azuero Peninsula revealed two faulted and folded slivers of oceanic crust attached to the trailing edge of the Caribbean Large Igneous Plateau (CLIP). Our new data, along with published geochronology, allowed us to reconstruct the Cretaceous forearc configuration of the trailing edge of the CLIP prior to seamount collision, ophiolite accretion, and whole-margin deformation. The ophiolite in western Azuero is composed of two tectonic slivers arranged in south-verging, imbricated thrust faults that stack a ~73 Ma pillow, flow, and picritic basalt and black chert, together with a ~ 89–93 Ma and older basalt flows and capping red chert sequences. Accretion of these slivers to form a supra-subduction zone ophiolite resulted from the middle Eocene collision and accretion of Galapagos seamounts against the trailing edge of the CLIP. Accreted seamounts are arranged in a north-verging antiformal stack duplex, and below the thrust sheets. Change in kinematics after fission of the Cocos-Nazca Plate during early Miocene times prompted the propagation of the Azuero-Sona fault zone flower structure, favouring the preservation of these slivers of oceanic crust. [ABSTRACT FROM AUTHOR]

This paper considers the suitability of using multispectral remote sensing data from the Landsat-8 satellite for conducting regional geological and mineralogical mapping of the territory of southeastern Zabaykalsky krai (Russia) under conditions of medium–low mountain relief and continental climate. To increase the spectral information content of Landsat-8 satellite data, statistical processing algorithms are used, including principal component analysis (PCA), minimum noise fraction (MNF), and independent component analysis (ICA). Statistical processing results are compared with the classes of geological materials: minerals of the oxide/hydroxide group containing transitional iron ions (Fe3+ and Fe3+/Fe2+); a group of clay minerals containing Al-OH and Fe, Mg-OH; and minerals containing divalent iron ion (Fe2+) and vegetation cover. Pseudocolor RGB composites are generated and interpreted, reflecting the distribution and multiplication of classes of geological materials. To build a prospectivity scheme for the discovery of the minerals, the integration of informative thematic layers is carried out using a fuzzy logic model. The resulting scheme is compared with geological information, and positive conclusions are made about the suitability of territory for further remote studies on mapping hydrothermally altered zones and hypergenesis products in order to localize areas that are promising for revealing hydrothermal–metasomatic mineralization. [ABSTRACT FROM AUTHOR]

In the course of this study, an approach is developed focused on identifying probabilistic zones of increased fracturing (areas with a high density of lineaments), considered a predictive sign for the localization of ore mineralization in the central part of the Maloural'skaya zone (the Polar Urals). This area is promising for the detection of polymetallic-type ore occurrences (Fe, Cu, Cu-Zn, and Au-Cu). Predictive schemes for the distribution of highly permeable rock zones are constructed and promising areas for polymetallic mineralization are identified based on this approach, accounting for the geological information, the distribution of mineral resources, remote sensing data and the results of their processing, and the lineament density schemes. The remote sensing data processing is based on the identification of structures by manual and automatic methods and their integration based on fuzzy logic. Morphostructural maps obtained from the Landsat-8 spacecraft data show that ore occurrences of polymetallic specialization known in the area are located along the perimeter of a large morphostructure of the first order, as well as near radial structures up to 20 km in length in the NE and (less often) in the NW direction. As a result of a comparison of remote sensing data with the geological map of the study area and known ore occurrences, six promising zones are identified. The contoured areas show spatial consistency with several known polymetallic ore occurrences localized in the study area. [ABSTRACT FROM AUTHOR]

In the 1970s, the geological mapping in Northeast Asia, in the Ul'ya–Urak interfluve was undertaken by the Aerogeologiya research and production enterprise, while E.L. Lebedev, an employee of the Geological Institute, USSR Academy of Sciences, collected plant fossils. Together with geologists of that enterprise, he developed a new stratigraphic chart of the region, which turned out to be incorrect, as appeared later, being based on ideas on the floral development in the mid-Cretaceous time. Lebedev made vast collections that include several thousand remains of ancient plants. However, this material turned out to be attributed to nonexistent stratigraphic units. This made it of little use for further study. Our investigation has demonstrated that the most representative collections made by Lebedev in the Ul'ya–Urak interfluve (taphofloras of the sites 101 and 107–110, 28, 20, 25, 27, 70–78, 153, 154) come from the first sequence of felsic volcanics of the homodromous succession of volcanism in the Okhotsk–Chukotka Volcanogenic Belt. In the Ul'ya Trough, this sequence was initially called the Amka Formation. It is shown that the previously collected palaeofloristic material is quite representative and in general is of a good preservation. In the future, it could be monographically studied and described as a large regional palaeofloristic and phytostratigraphic object—the Ul'ya flora. [ABSTRACT FROM AUTHOR]

The detailed three-dimensional density modeling results obtained for the upper part of the earth's crust in the area located in the northeastern part of the Voronezh crystalline massif at the junction of Losevo and Vorontsovka terranes are considered. The model obtained by solving the inverse gravimetry problem characterizes the rock density distribution in the crystalline basement to a depth of 16 km. An important role in such constructions is given to the starting model of the studied environment taking into account the available a priori geological and geophysical information: the regional density model of the East European Platform lithosphere and gravity field, data on rock density in the sedimentary cover and crystalline basement, estimated "gravity" layer thickness, the geological map of the crystalline basement, and digital elevation models of the region. The three-dimensional density model made it possible to specify the geological structure of the upper crust in the study area and to trace a deep continuation of surface structures of the basement. The obtained results are reliable due to the consistency of the accepted a priori data on the environment and agreement of model and observed gravity fields in the study area. [ABSTRACT FROM AUTHOR]

Barite mineralization is visible as veins in the Kuik‒Qureq area, southern part of Sanandaj zone, Western Iran. Geological and structural maps of the area were prepared using remote sensing data and field achievements. Statistical analysis of fractures included the ratio of distance and length to abundance, and also the calculation of the fractal dimension of fractures. This analysis indicates the role of structural controls on the barite mineralization in the region. Petro-fabrics were used to determine displacement and contribution of faults in barite mineralization. Geometric analysis using rose diagrams determined that the trends of the dominant fractures are N‒S and NN‒S, NNW‒SSE, WNW‒ESE and NNE‒SSW, and the main barite mineralization was formed along these faults. A tectonic model is presented for the region based on classifying fractures by azimuth and features observed in thin section. According to the proposed model, at least four stages of tectonic deformation affected the region and during these the direction of the σ1 axis changed in a clockwise direction. Barite mineralization mainly occurred in two stages: the first and main stage when first order fractures formed with the N‒S trend, and during the third deformation stage when secondary barite was deposited in third order fractures with an E‒W trend. [ABSTRACT FROM AUTHOR]

Fort Roberdeau was a lead mine in central Pennsylvania during the period of the American Revolution. Scant information exists on the original position of the fort, the location of mining activity in the area during the period of the Revolution, or artifacts from this period. Subsequent farming, mining exploration, and the placement of the current replica fort (erected 1976) obscure the landform and hinder identification of Revolutionary-period mining activities. As a means of locating where the mining activities occurred and the original position of the fort, this study integrates historical, geological, geophysical, geochemical, geomorphological, and archaeological data. Geological mapping identified potential areas of past mining, and geophysical resistivity surveys verified at least one Revolutionary-period mine, since the location and dimensions of the subsurface anomaly match historical records. The positions of period metallic artifacts in conjunction with a road and corner of the original fort (identified with LiDAR and thermal imagery) place the original fort near the current replica. [ABSTRACT FROM AUTHOR]

The Panjshir Fe-Polymetallic ore deposit is a valuable geological resource in Afghanistan, rich in iron and multiple essential metallic minerals, with substantial potential for industrial development. The exploration phase faces challenges related to the complex geological settings, high variability of mineral compositions, and the need for advanced geophysical techniques to accurately locate and assess valuable metallic resources. Considering the strong magnetic characteristics exhibited by Fe-Polymetallic elements, geomagnetic data were employed to analyze and map the likely prospectivity of Fe-Polymetallic deposits within the study area. Multi-scale edge detection techniques were employed to accurately map the boundaries of magnetic bodies by utilizing the upward continued analytical signal amplitude. The presence of a fault system on the geological map confirmed the structural information derived from our edge detection techniques. Advanced magnetic data inversion techniques were employed to create a three-dimensional representation of the distribution of magnetic bodies linked to Fe-Polymetallic deposits. In our efforts to reduce the impact of remnant magnetization in the study area, we adopted a comprehensive strategy by employing both magnetic susceptibility and magnetization vector inversion techniques. The use of a sparse and blocky norm regularization [0,1,1,1] is well-suited for magnetic susceptibility inversion, while a blocky norm [0000,0000,0000] is the appropriate choice for magnetization vector inversion in our study. Ultimately, the zones characterized by a high magnetic susceptibility and a high magnetization amplitude are considered promising areas for potential Fe-polymetallic occurrences. [ABSTRACT FROM AUTHOR]

The genus Aurelia is one of the most extensively studied within the class Scyphozoa. However, much of the research was historically attributed to the species Aurelia aurita (Linnaeus, 1758) before the recognition of its taxonomic complexity. Initially considered cosmopolitan and globally distributed, recent phylogenetic analysis has challenged this assumption. Consequently, the current distribution of species within the genus Aurelia and the processes that led to this distribution remain largely unexplored. After genetically confirming that the species traditionally present in the Mar Menor coastal lagoon in the southwestern Mediterranean corresponds to A. solida, we compiled data on the locations where moon jellyfish species have been genetically identified and mapped these coordinates to the geological period when the genus Aurelia diverged from other scyphozoan genera. We propose two hypotheses to explain the disjunct distribution of certain species. The first one assumes recent human-mediated introductions, while the second posits an absence of introductions. Both hypotheses, supported by fossil and historical records, suggest a Paleo-Tethys origin of the genus Aurelia. Migration from this area explains most of the genus's current distribution without human intervention, being the Mediterranean Sea, where A. solida should be considered autochthonous, part of their natural distribution range. [ABSTRACT FROM AUTHOR]

The analytic signal (AS1) has been widely used for mapping geological features from magnetic data. Some enhanced versions of the AS1 have been introduced to improve its effectiveness. Here, we compare the performance of these filters and introduce a filter obtained from the tilt angle and the directional analytic signals. For better performance on low latitudes, the directional analytic signals are obtained from the vertical integral of the magnetic anomaly rather than its magnetic potential. The proposed filter shows an apparent performance improvement in mapping the edges of magnetic sources, as shown with synthetic models and real example from the Olympic Peninsula, USA. The great advantage of the proposed technique is that the obtained result has lower influence from the magnetization vector direction than the AS1 and other related techniques. The findings demonstrate that the present method not only outlines the boundaries more precisely and clearly, but also reveals the presence of several structures obscured by nonmagnetic sediment in the study area, which are not determined by other methods. [ABSTRACT FROM AUTHOR]

The Dasuji giant porphyry molybdenum deposit is one of the largest ore deposits recently discovered along the Yinshan–Yanshan–Liaoning molybdenum belt in China. Using this deposit along the Yinshan–Yanshan–Liaoning molybdenum belt as the study area, the present study proposed a two-stage approach aimed at marking out the hydrothermally altered anomalies in the study area for the guidance of future prospecting in other regions. First of all, the Principal Component Analysis (PCA) and specific Band Ratio methods were applied to the ASTER images from different acquisition dates to extract ferric oxides and hydroxyl alterations related to the porphyry molybdenum deposit. Then, the Fractal-Aided Anomaly-Overlaying Selection model was adopted to recognize two ferric and hydroxyl alteration layers for separating anomalies from the interferences caused by geology and random noise from the data. Furthermore, for lithological differentiation in the previously marked off area, the Random Forest Classifier (RFC) was applied to the composite data obtained via the ASTER, ETM, and DEM, and it is demonstrated that the DEM can significantly improve lithological mapping in areas with complex vegetation cover and topography. Based on field verification and comparison with geological maps, the research revealed that the suggested two-stage approach may effectively reduce erroneously recognized anomalies produced during the first stage while retaining ore-related anomalies for gigantic porphyry molybdenum deposit prospecting in the Dasuji area, which showed the good application potential of the proposed model to extract actual hydrothermally altered anomalies adopted for lithological discrimination and mapping. [ABSTRACT FROM AUTHOR]

The Kravarsko area is located in a hilly region of northern Croatia, where numerous landslides endanger and damage houses, roads, water systems, and power lines. Nevertheless, natural hazard management plans are practically non-existent. Therefore, during the initial research, a landslide inventory was developed for the Kravarsko pilot area based on remote sensing data (high-resolution digital elevation models), and some of the landslides were investigated in detail. However, due to the complexity and vulnerability of the area, additional zoning of landslide-susceptible areas was needed. As a result, a slope gradient map, a map of engineering geological units, and a land-cover map were developed as inputs for the landslide susceptibility map. Additionally, based on the available data and a landslide inventory, a terrain stability map was developed for landslide management. Analysis and map development were performed within a geographical information system environment, and the terrain stability map with key infrastructure data was determined to be the "most user-friendly and practically usable" resource for non-expert users in natural hazard management, for example, the local administration. At the same time, the terrain stability map can easily provide practical information for the local community and population about the expected landslide "risk" depending on the location of infrastructure, estates, or objects of interest or for the purposes of future planning. [ABSTRACT FROM AUTHOR]

This paper reports on the Middlesboro impact structure (36°37′03″ N; 83°43′39″ W), a complex impact structure located in the Appalachian foreland fold‐and‐thrust belt of southeast Kentucky, USA. The structure forms a basin approximately 5.5 km in diameter exposing intensely deformed Pennsylvanian sediments. Based on field data, microstructural observation, and geophysical analyses we qualitatively assess degree and distribution of fragmentation of target rocks within the impact structure. Shock deformation features, especially feather features, are reported for the impact structure. Shallow seismic refraction data were acquired along a radial profile from outside the impact structure to the center of the structure. Seismic (P‐wave) velocity trends indicate that fracture intensity increases toward the center, reducing the overall seismic velocity. However, intense rock sealing in some parts of the central uplift increases the strength of rock samples and locally increases seismic velocities. We present a modified geologic map of the Middlesboro impact structure based on high‐resolution lineament analysis, field work, and reevaluation of existing structural data from geologic maps. The modified map suggests that crater circularity at Middlesboro is skewed by the reactivation of pre‐existing zones of structural anisotropy in the target. We propose that due to an oblique impact from northerly direction the sub‐horizontal Pine Mountain thrust plane beneath the impact structure became reactivated with a top‐to‐the south shear component. The impact‐induced formation/reactivation of the Doublings Fault Zone as a thrust ramp appears to have deflected the otherwise straight strike of the Cumberland Mountains southward. The Rocky Face fault approaches the crater rim fault, and we propose that this sinistral strike‐slip fault was formed, or at least reactivated, by the impact and accommodated the oblique impact's horizontal momentum. [ABSTRACT FROM AUTHOR]

The Eocene Anaconda metamorphic core complex is the most recently documented metamorphic core complex in the North American Cordillera. While much work has focused on constraining the nature and timing of core complex extension, earlier deformation preserved in its footwall is not as well understood. The Anaconda metamorphic core complex footwall contains an anomalously thin, lower- to uppermostamphibolite-facies section of Mesoproterozoic Belt Supergroup and Paleozoic metasedimentary strata. While the tectonic nature of this thinning is generally accepted, the mechanisms behind it remain enigmatic. Previous workers have hypothesized that footwall strata were attenuated along the upper limb of the Late Cretaceous Fishtrap recumbent anticline, a kilometer-scale, NW-vergent, recumbent fold exposed throughout the west-central metamorphic core complex footwall. New geologic mapping in the west-central Anaconda Range better constrains the nature and timing of tectonic attenuation in this structurally complex area. Two generations of folds were recognized: (1) F1 recumbent isoclines associated with the Fishtrap recumbent anticline and (2) F2 W-vergent asymmetric folds associated with map-scale N-plunging folds. F1 folds, axial planar S1 transposition fabrics, and bedding-parallel faults and shear zones boudinage, transpose, and omit strata of the Belt Supergroup. We suggest that the Fishtrap recumbent anticline tectonically attenuated the Belt Supergroup through Paleozoic section of the west-central Anaconda metamorphic core complex footwall, and we propose that it is a kilometer-scale, regionally significant structure. We further propose that the fold may have developed in response to rotational shear and sinistral transpression along the Lewis and Clark Line, which was further driven by accretion of outboard terranes along the western margin of North America during Late Cretaceous time. [ABSTRACT FROM AUTHOR]

Iron (Fe)-skarn mineralizations (Çambaşı, Dereli, Eğrikar, Karadağ, Kopuz, Sekü, Donguldere, Arnastal, Özdil, Ögene, İkizdere, Ovit Dağı, Kartiba, etc.) in the eastern part of the Pontides (NE Türkiye) are accommodated in the Pontide paleomagmatic arc and the eastern part of the Pontides Metallogenic Belt containing numerous various deposits. Fe-skarn mineralization around the Arnastal Plateau (Gümüşhane-Türkiye) is fragmentary in this area, which is covered with plants (grasses, flowers, etc.). Thus, it was attempted to describe the subsurface structures and Fe mineralization using an interpretation of the available geological and existing magnetic data in this area. Granitoid and volcano-sedimentary series (Upper Cretaceous) outcrop in the study area. These volcanosedimentary series consist of limestone, sandy limestone, marl, andesite, quartz andesite, basalt, and their equivalent pyroclastics. They include a thin layer of the red limestone (Upper Cretaceous) and olistolith recrystallized limestones (Jurassic-Lower Cretaceous). Zigana granitoid, intruding into all of these rocks, is high-K calc-alkaline and metaluminous and is classified as quartz monzonite, monzogranite, granite, and syenogranite as a result of its modal composition. Contact pyrometasomatic mineralization occurs in between the limestone and granitoids in the Arnastal Plateau. In addition to petrographic and mineralogical studies, magnetic methods were applied to an area of approximately 10 km2 to find any covered Fe deposits. Magnetic susceptibility values measured on the outcropped rocks ranged from 1 to 34 (10-7 SI) for limestone, 78 to 3750 (10-7 SI) for basalt, and 105 to 3946 (10-7 SI) for granitoids. It is considered that these ranges express the alteration (physical or chemical) of the rocks, their homogeneity, and the lack or presence of Fe minerals. The magnetic survey was conducted along a study area measuring 12,075 m long with 25 and/or 50 m station spacing. Processing of the magnetic data revealed the presence of eight buried Fe ores that could represent either massive or disseminated mineralization between the Sarıtaş and Kurtdere plateaus. Magnetite ore bodies may be present from the surface to a depth of approximately 15-25 m inside the limestone. In addition to the identification of new magnetite ore mineralization or bodies, a new geological map was designed by determining probable formation boundaries with this magnetic survey. [ABSTRACT FROM AUTHOR]