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Geological and lithological maps provide essential spatial data for various environmental assessments and studies. However, these maps lack detailed quantitative information on the geotechnical characteristics of rocks and soils, which limits their use for modelling purposes. This study addresses this gap by compiling a comprehensive database of over 2300 geotechnical parameter records searching the international literature. Focusing on cohesion, friction angle, and porosity, we analyse their distributions across different lithotypes, emphasising their significance in slope stability modelling. For the Italian territory, the collected information was used to associate geotechnical parameters to the lithological classes as identified by Bucci et al. 2022. These types of reclassified maps may provide researchers and stakeholders with a comprehensive dataset useful for slope stability assessment and land management at small scale. Descriptive statistics and validation from grey literature underscore the dataset's utility in enhancing geotechnical characterizations and supporting geological hazard assessments. [ABSTRACT FROM AUTHOR]

Crustal accretion at mid-ocean ridges governs the creation and evolution of the oceanic lithosphere. Generally accepted models1–4 of passive mantle upwelling and melting predict notably decreased crustal thickness at a spreading rate of less than 20 mm year−1. We conducted the first, to our knowledge, high-resolution ocean-bottom seismometer (OBS) experiment at the Gakkel Ridge in the Arctic Ocean and imaged the crustal structure of the slowest-spreading ridge on the Earth. Unexpectedly, we find that crustal thickness ranges between 3.3 km and 8.9 km along the ridge axis and it increased from about 4.5 km to about 7.5 km over the past 5 Myr in an across-axis profile. The highly variable crustal thickness and relatively large average value does not align with the prediction of passive mantle upwelling models. Instead, it can be explained by a model of buoyant active mantle flow driven by thermal and compositional density changes owing to melt extraction. The influence of active versus passive upwelling is predicted to increase with decreasing spreading rate. The process of active mantle upwelling is anticipated to be primarily influenced by mantle temperature and composition. This implies that the observed variability in crustal accretion, which includes notably varied crustal thickness, is probably an inherent characteristic of ultraslow-spreading ridges.Results from a high-resolution ocean-bottom seismometer experiment at the ultraslow-spreading Gakkel Ridge show unexpected highly variable crustal thickness and a relatively large average value, which can be explained by an active mantle upwelling model. [ABSTRACT FROM AUTHOR]

Anisotropic structures within the crust are frequently perceived to originate from stress-induced cracks, which have been mainly estimated on land through different wave speeds of orthogonally polarized S waves propagating in the anisotropic media. However, such estimations of crustal anisotropic structures in ocean areas, particularly for subduction zones around trenches, have not been investigated in detail due to the lack of long-term ocean bottom observations. In this study, we used ocean bottom seismometers of a permanent network deployed across the Japan Trench and the southern part of the Kuril Trench and applied the shear-wave splitting analysis to P-to-s converted waves extracted by receiver function analyses using teleseismic events. We estimated the anisotropic structures in marine sediments and oceanic crust for the incoming Pacific Plate and marine sediments for the overriding North American Plate. The obtained fast polarization directions for the incoming plate are mainly oriented to be parallel to the trench axis for the marine sediment and oceanic crust, which are formed by normal faults and cracks due to the upward plate bending in the outer-rise region, whereas results for marine sediments at the northern part of the Japan Trench are obliquely aligned to the trench axis. The oblique direction is consistent with the magnetic lineations of the incoming plate, indicating that ancient faults within the plate, which were formed in the shallow part of the crust during the creation of the oceanic plate at the ridge, are reactivated by the plate flexure. For the overriding plate, the fast polarization directions in the northern and southern parts of the study area are nearly normal to the trench axis. The central part shows two distinct features: the fast polarization directions parallel to the trench axis and small degrees of anisotropy. These patterns may reflect crack alignments associated with the lateral variation in postseismic crustal deformation after the 2011 Tohoku-Oki earthquake. Our results suggest substantial lateral variations in the stress field at the tip of the overriding plate along the strike direction. [ABSTRACT FROM AUTHOR]

Continental lithosphere is deformed, destroyed, or otherwise modified in several ways. Processes that modify the lithosphere include subduction, terrane accretion, orogenesis, rifting, volcanism/magmatism, lithospheric loss or delamination, small-scale or edge-driven convection, and plume-lithosphere interaction. The eastern North American margin (ENAM) provides an exceptional locale to study this broad suite of processes, having undergone multiple complete Wilson cycles of supercontinent formation and dispersal, along with ∼200 Ma of postrift evolution. Moreover, recent data collection efforts associated with EarthScope, GeoPRISMS, and related projects have led to a wealth of new observations in eastern North America. Here I highlight recent advances in our understanding of the structure of the continental lithosphere beneath eastern North America and the processes that have modified it through geologic time, with a focus on recent geophysical imaging that has illuminated the lithosphere in unprecedented detail. Eastern North America experienced a range of processes that deform, destroy, or modify continental lithosphere, providing new insights into how lithosphere evolves through time. Subduction and terrane accretion, continental rifting, and postrift evolution have all played a role in shaping lithospheric structure beneath eastern North America. Relict structures from past tectonic events are well-preserved in ENAM lithosphere; however, lithospheric modification that postdates the breakup of Pangea has also been significant. [ABSTRACT FROM AUTHOR]

Decorated vesicles in deep, seafloor basalts form abiotically, but show at least four life-analogous features, which makes them a candidate for origin of life research. These features are a physical enclosure, carbon-assimilatory catalysts, semi-permeable boundaries, and a source of usable energy. The nanometer-to-micron-sized spherules on the inner walls of decorated vesicles are proposed to function as mineral proto-enzymes. Chemically, these structures resemble synthetic FeS clusters shown to convert CO2, CO and H2 into methane, formate, and acetate. Secondary phyllosilicate minerals line the vesicles' inner walls and can span openings in the vesicles and thus can act as molecular sieves between the vesicles' interior and the surrounding aquifer. Lastly, basalt glass in the vesicle walls takes up protons, which replace cations in the silicate framework. This results in an inward proton flux, reciprocal outward flux of metal cations, more alkaline pH inside the vesicle than outside, and production of more phyllosilicates. Such life-like features could have been exploited to move decorated vesicles toward protolife systems. Decorated vesicles are proposed as study models of prebiotic systems that are expected to have existed on the early Earth and Earth-like exoplanets. Their analysis can lead to better understanding of changes in planetary geocycles during the origin of life. [ABSTRACT FROM AUTHOR]

Crassulaceae is a mid‐sized family of angiosperms, most species of which are herbaceous succulents, usually with 5‐merous flowers and one or two whorls of stamens. Although previous phylogenetic studies revealed seven major "clades" in Crassulaceae and greatly improved our understanding of the evolutionary history of the family, relationships among major clades are still contentious. In addition, the biogeographic origin and evolution of important morphological characters delimiting infrafamilial taxa have not been subject to formal biogeographic and character evolution analyses based on a well‐supported phylogeny backbone. In this study, we used plastomic data of 52 species, representing all major clades revealed in previous studies to reconstruct a robust phylogeny of Crassulaceae, based on which we unraveled the spatiotemporal framework of diversification of the family. We found that the family may originate in southern Africa and then dispersed to the Mediterranean, from there to eastern Asia, Macaronesia, and North America. The crown age of Crassulaceae was dated at ca. 63.93 million years ago, shortly after the Cretaceous–Paleogene (K‐Pg) boundary. We also traced the evolution of six important morphological characters previously used to delimit infrafamilial taxa and demonstrated widespread parallel and convergent evolution of both vegetative (life form and phyllotaxis) and floral characters (number of stamen whorls, petals free or fused, and flower merism). Our results provide a robust backbone phylogeny as a foundation for further investigations, and also some important new insights into biogeography and evolution of the family Crassulaceae. [ABSTRACT FROM AUTHOR]

The article discusses the importance of water in Earth's processes and the need to understand the water cycle between the surface and the deep mantle. It focuses on the hydration of oceanic lithosphere, which occurs through fractures on the seafloor and along faults and pores. The article explains the two stages of hydration, the methods used to estimate the extent of hydration, and the distribution of water input rates in different tectonic settings. It concludes that subduction zones play a critical role in mantle hydration and emphasizes the importance of understanding the dual hydration of oceanic lithosphere for plate dynamics and the water cycle of Earth. [Extracted from the article]

Devastating megathrust earthquakes and slow earthquakes both occur along subducting plate interfaces. These interplate seismic activities are strongly dependent on the nature of the plate interface, such as the shape of the plate interface and the materials and physical conditions along the plate interface. The oceanic plate, which is the input to the subduction zone, is the first order control on the nature of the plate interface. To reveal the nature of the subduction inputs to the northeastern Japan arc, we have conducted large-scale controlled-source seismic surveys of the northwestern part of the oceanic Pacific plate. The obtained seismic data have revealed (1) oceanic plate structural evolution caused by plate bending prior to subduction, suggesting the promotion of the oceanic plate hydration; (2) spatial variation of the oceanic plate structure, such as variations in the thickness of sediment and crust; (3) that the spatial variations are caused by both ancient plate formation processes and more recent volcanic activities; and (4) that spatial variations of the nature of the subduction inputs show good correlation with the along-strike variations in the seismic structure and seismic activities after subduction, including the coseismic slip distribution of the 2011 Tohoku earthquakes and the structural differences between the northern and the southern Japan Trench. These observations indicate that the incoming oceanic plate structure is much more spatially variable than previously thought and also imply that the spatial variation of the subduction inputs is a key controlling factor of the spatial variation of various processes in subduction zones, including interplate seismic activities and evolution of the forearc structure. [ABSTRACT FROM AUTHOR]

The thermal structure of subduction zones is fundamental to our understanding of physical and chemical processes that occur at active convergent plate margins. These include magma generation and related arc volcanism, shallow and deep seismicity, and metamorphic reactions that can release fluids. Computational models can predict the thermal structure to great numerical precision when models are fully described but this does not guarantee accuracy or applicability. In a trio of companion papers, the construction of thermal subduction zone models, their use in subduction zone studies, and their link to geophysical and geochemical observations are explored. In part I, the motivation to understand the thermal structure is presented based on experimental and observational studies. This is followed by a description of a selection of thermal models for the Japanese subduction zones. [ABSTRACT FROM AUTHOR]

This is the first high-resolution seismic study showing how the Chicxulub impact shaped the eastern slope of the Campeche Bank in the south-eastern Gulf of Mexico. The induced shock wave fractured Cretaceous strata causing the collapse of the upper slope and shelf over a length of ca. 200 km. Failed material was either transported downslope or remained in parts on the accommodation space created by the collapsed. In the Cenozoic, the East Campeche Plastered Drift developed within the created accommodation space, controlled by the inflowing surface current from the Caribbean, which forms the Loop Current. The internal reflection configuration of the drift shows that the closure of the Suwannee Strait in the Late Oligocene and the closure of the CAS in the Mid to Late Miocene controlled the variability of the southern Loop Current in time. Since the Loop Current transports heat and moisture from the western Atlantic warm water pool into the North Atlantic and further to NW Europe by the Gulf Stream, the drift represents an archive for controlling factors that influenced climate of the northern hemisphere. This first high-resolution seismic reflection study from the eastern Campeche Bank expands the understanding of destructive processes that a meteorite impact induces into the earth system. Furthermore, these data document that the East Campeche Plastered Drift bears the potential to understand the link between the climate variability of the northern hemisphere and oceanic processes in the equatorial western Atlantic. [ABSTRACT FROM AUTHOR]

Ladakh has a rich and fascinating sociocultural heritage owing to its unique geographical location and a mixture of varying civilizations. It covers a wide range of geological and geomorphic features of the western Himalaya including high mountain ranges, glacial valleys, saline to freshwater high-altitude lakes, and cold rocky desert. Himalaya is the product of a continent-continent collision between Indian and Eurasian plates and the closure of the Neo-Tethys Ocean during the Late Mesozoic to Early Tertiary. The Neo-Tethys Ocean existed during the Mesozoic Era and completely disappeared along the north dipping subduction zones. The Ladakh Himalayan Ophiolites (LHO) are the remnants of the eastern part of the Neo-Tethys Ocean that were obducted discontinuously along the Indus Suture Zone and incorporated on the Indian continental margin. These include Dras-Thasgam-Suru Valley-Shergol dismembered ophiolitic slices and Nidar-Spongtang ophiolitic complexes. These ophiolitic remnants comprise typical lithostratigraphy, viz., radiolarian cherts, pillow volcanics, gabbros, mafic-ultramafic cumulates, and mantle peridotites. They are scattered in the Ladakh region, accessible by foot and road, and form recognizable picturesque outcrops. They provide insights into the mantle sources, depth and degree of partial melting, melt-rock interaction, mantle wedge melting and metasomatism, and evolution of mantle-derived melts. In strength weakness opportunity threat analysis, the total weighted score (TWS) for the internal factor evaluation matrix is 3.22, indicating that strength exceeds weaknesses. While the TWS for the external factor evaluation matrix is 3.25, suggesting that the opportunity to develop and conserve the proposed geoheritage sites exceeds the threat. Thus, the LHO, with excellent aesthetic sense and good accessibility, are attractive from both scientific and geotourism perspectives. They must be recognized as valuable geoheritage sites worthy of protection and conservation against exploitation [ABSTRACT FROM AUTHOR]

The source of massive magma production at volcanic rifted margins remains strongly disputed since the first observations of thick lava piles in the 1980s. However, volumes of extruded and intruded melt products within rifted continental crust are still not accurately resolved using geophysical methods. Here we investigate the magma budget alongside the South Atlantic margins, at the onset of seafloor spreading, using high-quality seismic reflection profiles to accurately estimate the oceanic crustal thickness. We show that, along ~ 75% of the length of the Early-Cretaceous initial spreading centre, the crustal thickness is similar to regular oceanic thickness with an age > 100 Ma away from hot spots. Thus, most of the southernmost Atlantic Ocean opened without anomalously hot mantle, high magma supply being restricted to the Walvis Ridge area. We suggest that alternative explanations other than a hotter mantle should be favoured to explain the thick magmatic layer of seaward dipping reflectors landward of the initial mid-oceanic ridge. [ABSTRACT FROM AUTHOR]

The Cretaceous-Paleogene (K-Pg) mass extinction was geologically instantaneous, causing the most drastic extinction rates in Earth's History. The rapid species losses and environmental destruction from the Chicxulub impact at 66.02 Ma made the K-Pg the most comparable past event to today's projected "sixth" mass extinction. The extinction famously eliminated major clades of animals and plankton. However, for land plants, losses primarily occurred among species observed in regional studies but left no global trace at the family or major-clade level, leading to questions about whether there was a significant K-Pg plant extinction. We review emerging paleobotanical data from the Americas and argue that the evidence strongly favors profound (generally >50%), geographically heterogeneous species losses and recovery consistent with mass extinction. The heterogeneity appears to reflect several factors, including distance from the impact site and marine and latitudinal buffering of the impact winter. The ensuing transformations have affected all land life, including true angiosperm dominance in the world's forests, the birth of the hyperdiverse Neotropical rainforest biome, and evolutionary radiations leading to many crown angiosperm clades. Although the worst outcomes are still preventable, the sixth mass extinction could mirror the K-Pg event by eliminating comparable numbers of plant species in a geologic instant, impoverishing and eventually transforming terrestrial ecosystems while having little effect on global plant-family diversity. [ABSTRACT FROM AUTHOR]

The crustal accretion along mid-ocean ridges is known to be spreading-rate dependent. Along fast-spreading ridges, two-dimensional sheet-like mantle upwelling creates relatively uniform crust. In contrast, the crust formed along slow-spreading ridges shows large along-axis thickness variations with thicker crust at segment centres, which is hypothesised to be due a three-dimensional plume-like mantle upwelling or due to focused melt migration to segment centres. Using wide-angle seismic data acquired from the equatorial Atlantic Ocean, here we show that the crustal thickness is nearly uniform (~5.5 km) across five crustal segments for crust formed at the slow-spreading Mid-Atlantic Ridge with age varying from 8 to 70 Ma. The crustal velocities indicate that this crust is predominantly of magmatic origin. We suggest that this uniform magmatic crustal accretion is due to a two-dimensional sheet-like mantle upwelling facilitated by the long-offset transform faults in the equatorial Atlantic region and the presence of a high concentration of volatiles in the primitive melt in the mantle. Uniform magmatic crust formed at the Mid-Atlantic Ridge in the equatorial Atlantic Ocean reveals a two-dimensional mantle upwelling facilitated by the large transform faults and the high concentration of volatiles in the primitive melt in the mantle. [ABSTRACT FROM AUTHOR]

The lower Goodlands Member of the Turtle Mountain Formation is exposed in a streambank outcrop on the western flank of Turtle Mountain, south-western Manitoba, Canada (49°0′2″N, 100°14′51″W). This outcrop was sampled for a 1.5 m section of microfossil-rich non-marine clay and coal-rich sediments deposited in a coastal plain environment during the early Palaeocene. These sediments were deposited 65.4–65 Ma and thus offer an opportunity to reconstruct terrestrial palaeoecology 0.6 to 1 Ma after the Cretaceous–Paleogene boundary (K–Pg) extinction event. We use quantitative palynology to reconstruct terrestrial plant ecology and explore ecological patterns of recovery and succession of these communities on a millennial time scale. Quantitative palynological analyses shows that at the time of deposition of the Goodlands Member the landscape on the coastal plain of the Western Interior Seaway – in what is now south-western Manitoba – was covered in a forested canopied swamp with tall standing swamp cypress and other conifers, Juglandaceae (walnut family), birch, alder, elms and other angiosperms, with an understory of ferns and ground cover of Sphagnum moss. Notably, palms were present but scarce, indicating a relatively warm climate. No successional pattern of diversity and community composition is evident in the samples; all samples showed high plant diversity (33–54 taxa/sample, H′ 2–3). Vegetation in Manitoba recovered within 0.6 to 1 Ma following the K–Pg extinction event or was predominantly influenced by local environmental patterns independent of time. [ABSTRACT FROM AUTHOR]

Plate corners with extreme exhumation rates are important because they offer a perspective for understanding the interactions between tectonics and surface processes. The southern Alaskan margin with its curved convergent plate boundary and associated zones of localized uplift is a prime location to study active orogeny. Here, we present the results of fully-coupled thermo-mechanical (geodynamic) and geomorphologic numerical modelling, the design of which captures the key features of the studied area: subduction of oceanic lithosphere (Pacific plate) is adjacent to a pronounced asymmetric indenter dipping at a shallow angle (Yakutat microplate), which in turn is bounded to the east by a dextral strike-slip shear zone (Fairweather fault). The resulting first-order deformation/rock uplift patterns show strong similarities with observations. In particular, relatively young thermochronological ages are reproduced along the plate-bounding (Fairweather) transform fault and in the area of its transition to convergence (the St. Elias syntaxis). The focused exhumation of the Chugach Core also finds its equivalent in model predicted zones of high rock uplift rates in an isolated region above the indenter. From these results, we suggest that the general exhumation patterns observed in southern Alaska are controlled by mutually reinforcing effects of tectonic deformation and surface erosion processes. [ABSTRACT FROM AUTHOR]

Modeling gravity and magnetic anomalies over the Chicxulub crater are used to constrain the structure, stratigraphy, and asymmetries. Chicxulub is a multiring ~ 200 km rim diameter structure with a central uplift and well-preserved peak ring. The low relief terrain and physical property contrasts have facilitated geophysical modeling of the structure and impactite deposits. Nevertheless, contrasting models have been obtained due to data resolution limitations, uneven coverage, non-uniqueness solutions, boundary conditions, and heterogeneous/anisotropic media. We employ a multi-technique approach based on regional–residual separation, spectral analysis, first and second derivatives, upward and downward analytical continuations, horizontal gradients, analytical signal, Euler deconvolution, reduction to the pole, and forward modeling to constraint the anomaly sources, geometry and depths. Forward modeling of gravity anomaly favors central uplift flat-top models, whereas magnetic models show irregular shapes with a peak towards the NE, at 4–5 km depth. Analysis shows the effects of intersecting regional anomalies in the semicircular pattern that limit the definition of asymmetries, which constrains impact angle and trajectory, crater structure and pre-existing target features. Models link lateral–vertical density and magnetic property contrasts, distinguishing non-magnetic pre-and post-impact carbonates and carbonate-rich breccias from melt and basement rich breccias, and displaced, fractured impactites and basement uplift. [ABSTRACT FROM AUTHOR]

To fully assess the resilience and recovery of life in response to the Cretaceous–Paleogene (K-Pg) boundary mass extinction ~ 66 million years ago, it is paramount to understand biodiversity prior to the Chicxulub impact event. The peak ring of the Chicxulub impact structure offshore the Yucatán Peninsula (México) was recently drilled and extracted a ~ 100 m thick impact-generated, melt-bearing, polymict breccia (crater suevite), which preserved carbonate clasts with common biogenic structures. We pieced this information to reproduce for the first time the macrobenthic tracemaker community and marine paleoenvironment prior to a large impact event at the crater area by combining paleoichnology with micropaleontology. A variable macrobenthic tracemaker community was present prior to the impact (Cenomanian–Maastrichtian), which included soft bodied organisms such as annelids, crustaceans and bivalves, mainly colonizing softgrounds in marine oxygenated, nutrient rich, conditions. Trace fossil assemblage from these upper Cretaceous core lithologies, with dominant Planolites and frequent Chondrites, corresponds well with that in the overlying post-impact Paleogene sediments. This reveals that the K-Pg impact event had no significant effects (i.e., extinction) on the composition of the macroinvertebrate tracemaker community in the Chicxulub region. [ABSTRACT FROM AUTHOR]

Deception Island is an active volcano located in the South Shetland Islands, Antarctica. Although the last eruptions occurred in 1967-1970, the volcano has undergone periods of seismic unrest in 1992, 1999, and 2015. In this work, we analyze continuous seismic data obtained by a permanent station for the period 2008-2015 preceding the 2015 unrest. We identify different types of seismic signals including tectonic and volcano-tectonic (VT) earthquakes and long-period (LP) seismicity, using a combination of visual and automated techniques. The temporal evolution of the seismicity displays three differentiated stages. In Phase 1 (2008-2010) the volcano was in a dormant state characterized by a moderate level of seismicity dominated by low-energy LP seismicity, and very few VT earthquakes. In Phase 2 (2011-2014), there was a gradual increase in the level of LP events and tremor, and an acceleration of the number and energy of VT earthquakes. In Phase 3 (2014-2015) the seismicity reached a climax, with the occurrence of seismic swarms comprising thousands of earthquakes, displaying maximum activity in September-October 2014 and February 2015. We propose that the change from Phase 1 to Phase 2 was due to the recharge of magma into the plumbing system at Moho depths. The emplacement of fresh magma increased the amount of gas (and heat) permeating the volcano edifice, triggering VT earthquakes in brittle regions and favoring the occurrence of LP seismicity in the shallow hydrothermal system. During Phase 2 magma ascended through the plumbing system, as evidenced by the acceleration of the seismicity rates, the detection of thermal anomalies, and a change in the deformation pattern that for 2013-2015 corresponded to an inflation process. Finally, in Phase 3 the magma intrusion reached its shallowest point before stalling at a depth of 6-10 km. The stress perturbations propagated through crustal fluids and produced a distal VT swarm SE of Livingston, as well as proximal VT swarms and very intense LP seismicity at Deception Island. [ABSTRACT FROM AUTHOR]

The Alaska subduction zone is characterized by a subducting oceanic plateau, which is referred to as the Yakutat terrane. Tectonic tremors occur in this zone, and there are few volcanoes above the subducted Yakutat terrane. In this study, we performed a 3-D numerical simulation of a thermal structure associated with the simultaneous subduction of the Yakutat terrane and Pacific plate to elucidate the mechanism of tectonic tremors, which typically involve the presence of water. We calculated the water content distribution near the slab surface by using the thermal structure obtained from our simulation and phase diagrams of the hydrous minerals included in the slab. As a result, dehydration from the marine sedimentary layer and oceanic crust was observed near the area where tectonic tremors occurred. Tectonic tremors occur only in the Yakutat terrane because the marine sedimentary layer and oceanic crust are thicker there, and the total amount of water content in these layers is higher; therefore, the amount of dehydration is also higher there than in the Pacific plate. Additionally, there are few volcanoes above the subducted Yakutat terrane because little water remains within the slab beneath the volcanic chain where magma is produced. [ABSTRACT FROM AUTHOR]

The Hangay Dome in central Mongolia, a typical intraplate plateau far from plate boundaries, is characterized by rapid uplift and widespread volcanic activities in the Cenozoic. However, thermodynamics process for the landform in Cenozoic remains mysterious. Seismic Lg-wave, which is sensitive to crustal thermal status, can provide constraints on the crustal attenuation structure; thus, may be helpful to understand the thermodynamics. In this study, we estimate the Lg-wave quality factor QLg across the Hangay Dome and its surroundings from 231 crustal earthquakes recorded by 136 regional broadband seismic stations distributed throughout north China and Mongolia. Using a joint tomographic method, we construct a broadband Lg attenuation model at 58 discrete frequencies distributed evenly in log scale between 0.1 and 20.0 Hz. The obtained QLg model provides new insights into crustal attenuation in the region. The strong Lg wave attenuation observed in the northeastern Hangay Dome and western Gobi-Altai, associated with crust low-resistivity anomalies, low S-wave velocity region, heat flow and volcanic activities, suggest the existence of possible partial melting due to asthenospheric upwelling. The widespread moderately-low QLg values around the perimeter of the Hangay Dome imply that the margin of the Hangay Dome has been weakened. The center part of the uplift is a small high QLg nucleus, which is possibly the residue of the Precambrian basement. The above observations suggest that the Hangay Dome is lifted by small-scale asthenospheric upwellings. During this process, the very hot mantle materials strongly modified the Hangar Dome and also caused the Cenozoic volcanism and major earthquakes. [ABSTRACT FROM AUTHOR]

The present study attempts a conjugate analysis of satellite-based remote sensing, gravity, and magnetic data for evaluation of structures and tectonic for new insights on Kimberlite emplacement around the Bundelkhand Craton. Initially, Landsat Operational Land Imager (OLI) data has been enhanced using high-pass filtering for the delineation of lineaments. A combined lineament density map has been prepared from the processed Landsat image, Bouguer gravity, and RTP (Reduction to pole) magnetic data, which are further correlated with the reported Kimberlite/Lamproite pipes. The depth to the lithospheric Mantle of the study area has been estimated from EIGEN6C4 Bouguer gravity data using the Parker-Oldenburg algorithm. The association of the reported Kimberlite/Lamproite pipes in the study area have been analyzed with the i) composite lineament density map, ii) different mantle blocks of high and low Moho depths, iii) lithospheric mantle density, and iv) tectonic setting. Some new potential zones for Kimberlite/Lamproites emplacement have been identified based on the integrated analysis of the above mentioned parameters. [ABSTRACT FROM AUTHOR]