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Aim: To date a vicariant event through the mutualistic relationship of a hylid frog and its bromeliad host found across two isolated mountain ranges as part of an island–continental split and to use this information to calibrate a molecular dating analysis of hylids. Location: South America. Time Period: Pliocene. Major Taxa Studied: Treefrogs, Arboranae. Methods: Pliocene tectonic movements sank a portion of a mountain range that connected present‐day Trinidad (island) and northern Venezuela, eventually isolating populations of the golden tree frog Phytotriades auratus and its host bromeliad Glomeropitcairnia erectiflora on both sides of a saltwater barrier. We estimated the submersion rate timing of the vicariant event, then employed ecological niche modelling to establish the distribution of the frog and its host to the Pliocene. We generated nucleotide sequence data for the hylid on each side of the marine barrier and proposed a biogeographic calibration for the split between populations. Using Bayesian phylogenetic analysis, we evaluated the impact of incorporating this biogeographic calibration on estimates of treefrog divergence times. Results: A relatively continuous, high‐elevation mountain range existed before the Pliocene and the opening of the Gulf of Paria (4.45 ± 0.85 Ma). Phytotriades auratus and G. erectiflora would have been distributed across the Paria and Northern Range mountains as a single population since the Pliocene. Divergence times among treefrogs (Arboranae) were older than those inferred using fossil calibrations alone, with mean age estimates for subfamilies and genera being ~2 and ~1.2 million years older, respectively. Main Conclusions: Our study presents a biogeographic calibration based on a vicariant model that connects the evolution of the populations of a hylid through geology and ecological data. The implementation of this date as a molecular clock calibration reduces the uncertainty in date estimates for the shallower nodes in the phylogeny of Arboranae. [ABSTRACT FROM AUTHOR]

Jurassic and Palaeocene tidal deposits of the epeiric Western Interior Sea in Wyoming, USA, differ significantly due to their contrasting climates and tectonic, geographic and depositional settings. Tidally generated, cross‐bedded sandstone bodies contained by incisions are common to both settings and can potentially be uncritically attributed to marine flooding of fluvial systems. Key differences in lithology, ichnology and relationships with surrounding sediment reveal fundamentally different depositional settings, however. The Jurassic system occupied a low accommodation, semi‐arid environment, with geographically open shorelines as relative sea‐level fell, creating an unconformable contact with the underlying, storm wave‐dominated shelf and shoreface deposits. Siliciclastic, intertidal flats formed adjacent to coastal aeolian and fluvial environments during brief turnarounds from the degradational (forced regressive) to aggradational and retrogradational (transgressive) system tract. Basinward of these environments, metre to decimetre‐scale cross‐bedded, bioclastic, subtidal compound dunes and tidal inlet complexes accumulated in areas of minimal clastic flux and within incisions created by submarine tidal currents. By contrast, the Palaeocene tidal systems formed in a high accommodation, subtropical setting, as rising sea levels forced the fluvial to marine transition zone landward and flooded coastal swamps, forming geographically irregular, back‐barrier complexes and tidally influenced fluvial systems. High volumes of siliciclastics, terrigenous organic material and freshwater were delivered by the rivers and created physicochemical stress on the marine embayments. Sandy tidal flat deposits accumulated in lagoons and interdistributary bays, but unlike the Jurassic examples, they do not mark a turnaround from the falling stage to the transgressive system tract. The potential preservation window for tidalites is significantly greater vertically in the aggradational to retrogradational setting than in the degradational system due to greater accommodation. The preservation window is vertically smaller, but areally greater in the Jurassic, forced regressive system because of basinward enhancement of tidal currents driven by complex palaeobathymetry caused by tectonic activity of local pre‐Laramide uplifts. [ABSTRACT FROM AUTHOR]

The Tarim Craton is an ancient Precambrian continental block, and detailed knowledge of its thermo‐tectonic history is crucial for understanding the early history of continental evolution. Abundant layered mafic rocks, which have commonly been regarded as basalts, occur within the Ediacaran Sugetbrak Formation (Fm.) in the Aksu region of the northwestern Tarim Craton. Clear intrusive features have now been discovered, including mafic rocks truncating Ediacaran sedimentary layers, exhibiting an intrusion‐baked margin where they interact with both the overlying and bottom wall rocks, and displaying a fine‐grained transition zone from their interior to their margins. The new findings demonstrate that these mafic rocks within the Aksu Ediacaran strata were not erupted basalts but instead are intrusive diabase dykes. Therefore, these mafic rocks cannot be used to constrain the timing of the Sugetbrak Fm. in the Aksu area, nor as marker layers for regional stratigraphic correlation. Furthermore, the Ediacaran thermo‐tectonic evolution in this region, deduced from the assumption that the mafic rocks are lavas, needs to be revised. [ABSTRACT FROM AUTHOR]

The distribution of oxidation - reduction interfaces is of significance in mining production and exploration. By organizing geological exploration, mine geology, and production exploration data from Wandongshan ore section of Beiya gold polymetallic deposit, the factors influencing the distribution of the oxidation reduction interface were analyzed. Comparative analysis revealed that stratigraphy, intrusive rocks, tectonic structures, and hydrogeological conditions are the main factors affecting the distribution of the oxidation reduction interface while folding structures have no impact on its variation. Studying the 3D spatial distribution characteristics of the oxidation reduction interface and establishing a more accurate 3D spatial model are crucial for ensuring the accuracy of production planning and the determination of construction organization schemes. This allows for the efficient utilization of resources. [ABSTRACT FROM AUTHOR]

In this study, we investigated Early Paleozoic magmatic rocks of the Manlai Formation exposed along the eastern margin of the Lancang terrane to better understand the tectonic history of the Proto-Tethys. We present petrological, geochemical and whole-rock Sr-Nd and zircon Hf isotopic data for basalts and gabbros sampled from the Qianmai mélange. Zircon grains from six basaltic and gabbroic samples yielded U-Pb ages of 495–482 Ma. These rocks are characterized by tholeiitic and Nb-enriched compositions, with Nb/La ratios in the range of 0.38–1.38, similar to the typical Nb-enriched basalts. All the mafic rocks show slightly negative to positive εNd(t) (−1.67 to + 4.32) and zircon εHf(t) values (−7.3 to +3.8). Elemental and isotopic data suggest that the Qianmai Nb-enriched mafic rocks were mainly derived from the mixing of an OIB-like source with a subduction-modified mantle wedge source. Together with magmatic and sedimentary records of similar ages in the Lancang terrane and the Baoshan Block, our results reveal Early Paleozoic magmatic and sedimentary sequences along an active margin of the Proto-Tethys. Taking into account the recently identified Early Paleozoic ophiolitic mélange in the Yunxian-Menghai belt, we consider the Qianmai magmatic rocks to represent the products of early-stage subduction-related magmatism within a primitive island arc or fore-arc setting associated with the southward subduction of the Proto-Tethys. We infer that prolonged south-dipping subduction on the northern margin of Gondwana persisted from the Cambrian to the Late Ordovician. [ABSTRACT FROM AUTHOR]

The Zagros Fold and Thrust Belt (ZFB) in southwestern Iran emerges as a geological marvel, defined by series of compact anticlines and synclines that the NW–SE trending structures of the Zagros belt. This unique configuration designates the ZFB as the dynamic boundary of the Arabian platform, shaped by the forces of nature. Over time, sedimentation in the expansive basin led to a gradual transformation, with folds originally oriented differently nowfolds axial line inclining southwestward, revealing a progressive shift in fold axial planes. This article presents a pioneering tectono-stratigraphic examination of Miocene Formations in the Fars and Bandar Abbas Hinterland, Southern Iran. The study meticulously explores five locations—Bastak, Taghdis-e Bahar, Dasht-e Arzhan, Saedi Mountain, and Yasuj—analyzing stratigraphic sections of the Miocene Formation. The Isopach map exposes variations in Miocene Formation thicknesses across these sites. In the Arjan plain, significant facies change unfolds, transitioning from Gachsaran Formation's evaporitic sedimentary rocks to Rzak Formation's marine sedimentary rocks and Asmari Formation's calcareous rocks along a northwest–southwest border. These facies change correlates intricately with subtle movements of fault zones—Kareh–Bas, Sabzpooshan, Sarvestan, and Kazerun. The tectono-stratigraphic journey unveils a profound connection between changes in sedimentary basin depth and nuanced alterations in sedimentary rocks' facies, orchestrated by the interplay of various basement faults, some following the Arabian trend, others aligning with the majestic Zagros trend—a symphony of geological forces shaping the Miocene narrative in the Fars and Bandar Abbas Hinterland. [ABSTRACT FROM AUTHOR]

In the case of modern river sediments, source rocks, tectonic setting, and climatic and geomorphological conditions are fully known, diagenetic effects are by definition none, and physical and chemical processes during erosion, transport, and deposition can be investigated directly in any required detail. Their study thus provides the fundamental information needed to understand the impact of various controls on sediment generation and sediment routing systems in diverse geological settings. With the growing interest in source‐to‐sink sedimentary systems for economic purposes, researchers have focused more and more on modern environments, producing an ever‐increasing amount of compositional data on river sediments. To better integrate and utilize these large datasets, we systematically compiled a global database of 4,208 fluvial sediment samples compiled from 100 published papers, book chapters, and dissertations and included 3,747 petrographic and 1,943 heavy‐mineral analyses. The analysed samples are mostly located in Asia, Africa, Europe, and South America, with fewer examples from North America and Oceania. Each sample is complemented by metadata describing references, river name, geographic location, sampling date, analytical method, and grain size, so that samples can be grouped and filtered to meet different needs including comparison with other datasets. We compiled a global database of 4,208 fluvial sediment samples with 3,747 petrographic and 1,943 heavy‐mineral analyses. Each sample is complemented by metadata describing references, river name, geographic location, sampling date, analytical method, and grain size, so that samples can be grouped and filtered to meet different needs. The database provides fundamental information needed to understand the impact of various controls on sediment generation and sediment routing systems in diverse geological settings. [ABSTRACT FROM AUTHOR]

The Mamonia Mélange in the Ayia Varvara area (southwestern Cyprus) is characterized by a matrix supported mélange which is composed of tectonized siltstones and mudstones with numerous blocks that were derived from the Mamonia Allochthonous Complex (Petra tou Romiou Formation reefal limestones, Phasoula Formation volcanics, Kholetria Member pelagic limestones, Akamas Member sandstone, Parekklisha Member sandstone, Ayia Varvara Formation metamorphics and Episkopi Formation radiolarian cherts). Subordinate blocks were derived from the Troodos Ophiolite Complex: serpentinites, gabbro, pillow lavas and cherty umbers (Perapedhi Formation). Radiolarian assemblages from chert blocks display a broad spectrum in age, ranging from the Late Triassic (latest Carnian–early Norian) to the youngest Cenomanian. The composition of the mélange in the Ayia Varvara area differs from the one described in the Petra tou Romiou area (SW Cyprus), as various lithologies were recorded (like Akamas Member sandstone and Parekklisha Member sandstone) which were not detected previously. The Mamonia Mélange was formed during the Late Cretaceous, most probably after the end of deposition of the Perapedhi Formation (late Santonian–early Campanian). [ABSTRACT FROM AUTHOR]

[Display omitted] • Igneous geochemistry used to map paleoelevations of South America. • Maps for Cenozoic-present broadly agree with independent constraints. • Results identify areas for improvement in global paleoelevation models. Mountains and mountain ranges, often situated at convergent plate margins, play a pivotal role in many fields of the Earth, climate, and biological sciences. Reconstructing past episodes of mountain building from the geological rock record is one of the main challenges for unravelling the ancient physical geography of Earth's surface. Established methods for quantifying past elevations traditionally relied on sedimentary rocks, but in recent years, alternative approaches have emerged on the basis that geochemical signatures of magmatic rocks formed in convergent settings correlate with crustal thickness or elevation. Consequently, methods based on igneous samples have the potential to allow quantitative mapping of past topographic change for large spans of space and time where existing maps are largely based on a qualitative approach. Here, we investigate the application of paleoelevation estimates derived from geochemistry using the western margin of South America as a case study. We investigate their consistency with independent indicators of past elevations such as stratigraphy, stable isotopes, fossils etc. for Cenozoic samples along the Andean margin. For older times, we compare the estimated paleoelevations with more general aspects of the geological record, as well as paleoelevations from global paleogeography models widely used in climate modelling studies, to evaluate the extent to which these models are consistent with the igneous geochemical proxies. We find that estimates based on multiple geochemical proxies, and which account for variations in elevation as a function of MgO, are preferable to those based on individual proxies. The multi-mohometer estimates yield estimates of elevation that better match both present-day topography and Cenozoic paleoelevations, and retain more samples during the data filtering stage. In deeper time, we show that igneous geochemistry quantifies changes in elevation related to documented phases of crustal thickening and thinning, and is thus likely to allow improvements to existing maps of paleotopography. [ABSTRACT FROM AUTHOR]

The lithosphere of Mars accommodates horizontal shortening through folding and faulting, producing landforms described as wrinkle ridges or lobate scarps. Despite this nomenclature, we lack a deep understanding of the drivers of morphological differences observed between landform types. This study aims to develop a quantitative model for shortening landform classification based on surface morphology, subsurface architecture, and strain accommodation, facilitating interpretations of where and how lithospheric stresses are recorded. We developed this model by mapping 100 shortening landforms in a Geographic Information System, recording 12 unique geomorphic parameters such as length and asymmetry, and estimating the strain of each landform. We conducted a Discriminant Function Analysis (DFA) using surface morphometrics. This DFA produced a predictive linear function for categorizing wrinkle ridges and lobate scarps and for quantifying which landforms were exemplars within those categories. The three most influential variables on the surface morphometry DFA were the maximum width, forelimb slope, and back limb length. We then modeled the subsurface structural geology of 50 landforms using MOVE Structural Geology Modeling Software and conducted a second DFA based on subsurface metrics. DFA was most influenced by the dip and depth of the lower ramp base. When both surface morphology and subsurface geometry are input into single DFA, wrinkle ridges and lobate scarps can be distinguished quantitatively 96% of the time. Our results also show that lobate scarps accommodate more strain and imply that studies should consider landform type when interpreting local, regional, and global geological stress histories. Plain Language Summary: The tectonic structures of a planet record its geologic history. Some of these structures, such as those classified as lobate scarps and wrinkle ridges, account for the horizontal shortening of the planet's surface. These two groups of shortening structures are observed on the surface of almost every rocky planet. Planetary geologists have historically assumed that wrinkle ridges and lobate scarps represent different types or amounts of shortening based on differences in their visual morphologies. In this work, we mapped 100 of these landforms on Mars and quantified their surface characteristics. We then further analyzed 50 landforms using a structural geology modeling software to assess their subsurface fault and fold geometries. Using the parameters we measured, we applied a statistical analysis called a Discriminant Function Analysis to quantify and learn about the differences between these landform types. We find that lobate scarps are rooted by faults that extend deeper into the subsurface than faults that underly wrinkle ridges, and that because of the greater variability in landform characteristics, lobate scarps may represent a range of stages in the formation of these landforms while wrinkle ridges developed entirely during one phase of the geologic history of Mars. Key Points: Shortening landforms on Mars were analyzed at the surface and subsurface to quantify their morphometrics and structural geometriesTraditional definitions of lobate scarps and wrinkle ridges are end member descriptions of landforms that exist across a morphological spectrumLobate scarps are fault‐dominated structures while wrinkle ridges are fold‐dominated structures [ABSTRACT FROM AUTHOR]

Large topographic rises on Venus are regions thought to be formed in response to the presence of a mantle plume or mantle upwelling, equivalent to hot spots on Earth. In this work, we study the geology and evolution of one of these large topographic rises, Imdr Regio, based on geologic mapping and analysis of geophysical data of the area. Imdr Regio presents a complex structure with two very different areas: (a) an elevated southeast area that is dominated by volcanism associated with Idunn Mons, a large volcano that has been proposed as a site of recent or even active volcanism; (b) another elevated area in the northwest area that also has a large volcano (Arasy Mons), but that is dominated by volcanism and tectonic activity associated with the formation of the Olapa Chasma rift system. These two very differentiated topographically elevated areas also exhibit differences in their geology, volcanic and tectonic style, and geophysical characteristics, which leads us to suggest that more than the classic volcano‐dominated rise classification attributed to Imdr Regio the area could rather be considered as an intermediate or hybrid volcano‐rift dominated large topographic rise. The evaluation of the different genetic scenarios and its correspondence with the observed geology in the area suggests that the complex geology of Imdr Regio could be better explained if we consider models of hot spot evolution that involve the presence of several mantle plumes or secondary upwellings derived from a mantle plume emplaced at a deeper rheological boundary. Plain Language Summary: Large topographic rises on Venus are the equivalent to hot spots like those responsible for the formation of Hawaii on the Earth. We have studied the geologic evolution of one of these large topographic rises, Imdr Regio, and this research shows that Imdr Regio is complex with two differentiated areas. The southeast is dominated by a large volcano, Idunn Mons, that has been proposed as a site of recent or even active volcanism. In the northwest there is also a large volcano Arasy Mons, but the activity is dominated by the Olapa Chasma rift system. The presence of these two areas with differences in their geology, volcanic and tectonic style, and geophysical characteristics, leads us to suggest that, although this large topographic rise was classified as dominated by the volcano, it could indeed be better classified as an intermediate or hybrid volcano‐rift dominated rise. We also evaluate the different scenarios to explain its formation and conclude that the complex geology of Imdr Regio could be better explained if we consider models of hot spot evolution that involve the presence of several mantle plumes or secondary smaller plumes derived from a mantle plume emplaced at a greater depth. Key Points: We have studied the geology of Imdr Regio, a possible active hotspot on Venus, based on geologic mapping and analysis of geophysical dataImdr Regio presents complex geology dominated by Idunn Mons and Olapa Chasma, classifying it as a hybrid volcano‐rift large topographic riseThe complex geology and the topography of Imdr Regio suggest that it could be the result of multiple or secondary plumes in the area [ABSTRACT FROM AUTHOR]

Landscapes are the integrated product of external forcings (e.g. tectonics and climate) and intrinsic characteristics (e.g. bedrock erodibility). In principle, hard bedrock with low erodibility can steepen rivers in a similar way to tectonic uplift. A key challenge in geomorphic analysis is thus separating the tectonic and lithological effects on landscapes. To address this, we focus on multiple rivers that are transiently incising through contrasting lithologies in the Gulf of Corinth, Greece, where tectonic history is broadly well constrained. We first exploit topographic metrics and river long profiles to demonstrate that landscapes are responding to both tectonics and lithology. In particular, the long profiles are divided into knickpoint‐bounded segments, and at this scale, channel steepness is shown to be more sensitive to lithology than the entire catchment, possibly due to relatively uniform erosion rate at the segment scale. We then use segment‐scale steepness variations between different lithologies to constrain their relative erodibilities (Klime:Kcong.:Ksand‐silt:Kp‐con sed. = 1:2:3:4), which are further converted into actual lithology‐dependent erodibilities by modelling a well‐constrained, ca. 700 ka knickpoint in the Vouraikos catchment. The effectiveness of lithology‐dependent erodibilities is supported by the observation that if lithology‐dependent erodibilities are used to calibrate studied river long profiles in χ distance, we obtain long profile concavities that fall within the theoretical range. Finally, we use lithology‐calibrated metrics to provide new geomorphic constraints on the timing and magnitude of tectonic perturbations in these catchments. These geomorphic results are interpreted in conjunction with previous onshore and offshore studies to shed new light on fault growth and linkage history in the Gulf of Corinth. Our study therefore provides a topographic analysis‐based approach to quantify lithological effects on transient catchments, with important implications for tectonic interpretations of topographic metrics in lithologically heterogenous landscapes. [ABSTRACT FROM AUTHOR]

Two sediment sections are investigated at Cape Arkhangelos, island of Rhodes, where Pleistocene marine sediments crop out in horsts and grabens of a Mesozoic basement. There, hemipelagic sediments characterized by upper bathyal communities are atypically mixed with much shallower faunal components because they were deposited close to rugged coastal landforms. Biostratigraphic analyses show that the sections were deposited between 1.8 and 0.9 Ma, and between 1.8 and 1.6 Ma, respectively. By combining the planktonic/benthic foraminiferal ratio with 31 bathymetric indicators chosen among extant species of benthic foraminifera, mollusks, and bryozoans, we show that relative sea-level fluctuations can be reconstructed in these atypical settings despite the proximity of steep slopes that favored transportation of allochthonous fauna. The shallow-water components (including gravels and calcareous algae) were transported downslope by the combined action of gravity, currents, and tectonic disturbance that promoted drowning (with a maximum flooding recorded at ca. 1.7 Ma) and then uplift of fault-bounded paleovalleys that formed during the Early Pleistocene. Abrupt facies changes and age differences between sections have been triggered by the irregular paleotopography of the Mesozoic basement, which fostered differential depositional settings, with outer to middle neritic deposits above the horsts and upper bathyal deposits in paleovalleys. [ABSTRACT FROM AUTHOR]

Kosovo is distinguished by a particularly high degree of seismic activity as a result of its location in the alpine-Mediterranean seismic area. The thickness of the seismic zone in the Earth's crust is a crucial element in seismotectonics, as it affects the design of fault systems, relative fault activity, earthquake size and distribution within a fault system, and the long-term accumulation of tectonic deformation. Kosovo's large depressions and high relief make it challenging geomorphologically. The country of Kosovo is divided into numerous chunks along the fault lines because of the inclinations of these prevalent motions. Normal faults, along which differentiations on the order of 2000 m occurred during the neotectonics period, identify the contacts between these blocks. Understanding Kosovo's seismotectonic characteristics requires an exact analysis of hypocenter parameters when historical earthquakes that have struck the country are reassessed for magnitude. This study deals with the seismicity and tectonics of the territorial space of the Republic of Kosovo. [ABSTRACT FROM AUTHOR]

Impact craters are a unique tool not only for inferring ages of planetary surfaces and examining geological processes, but also for exploring subsurface properties. We use ejecta blankets as proxies to obtain insights into the subsurface characteristics and the vertical stratification of Ganymede's icy crust. We investigated 36 prominent ray and halo craters using images acquired during the Voyager, Galileo, and Juno spacecraft missions. These craters exhibit diverse characteristics, including dark rays, bright rays, or their combination, in both continuous and discontinuous patterns as well as dark and bright halos. Dark halo craters (DHCs) have the smallest radial extents of their dark ejecta deposits, while dark ray craters (DRCs) have the largest. DRCs in dark terrain suggest a thickness of less than ∼2 km based on their excavation depths. DRCs and DHCs craters located in light terrain (LT) reveal significant heterogeneity in the uppermost portions of icy crust at various locations. DRCs and DHCs in the LT require the presence of at least one layer of dark material. This is the case if the LT is formed by tectonic rifting and graben formation. In contrast, if the LT is formed by tectonic spreading, bright halo and ray craters are expected to form. Key Points: We utilized ray and halo craters on Ganymede to determine the vertical stratigraphy of its icy crustThe excavation depths of dark ray craters in Ganymede's dark terrain suggest kilometer thick dark terrain layersThe ejecta facies of impact craters allow to narrow down the tectonic regime of crustal extension (rifting or spreading) [ABSTRACT FROM AUTHOR]

Models of active deformation of the Earth's crust are predominantly represented with dislocations having a downdip continuation into the lower crust, where the fault slips continuously. This model predicts surface strain accumulation concentrated near the fault during the interseismic period. In an alternative model, faults do not extend beneath the elastic portion of the crust and are accompanied by a wide zone of distributed shear underneath, predicting a more constant strain rate lacking concentrations at the faults. We use high‐precision GPS data collected across the northern and central Walker Lane, USA— a region of complex faulting near the western edge of the Basin and Range Province to evaluate which model is appropriate. Despite the existence of dense continuous and semi‐continuous geodetic networks that have been surveyed for ∼20 years, the horizontal velocities reveal no evidence of localized strain accumulation across the fault surface expressions. Instead, deformation within the Walker Lane is uniformly linear, suggesting that the surface deformation reflects distributed shear within the ductile crust rather than focused deformation at faults. This suggests no downdip extension of the faults below the seismogenic layer. The shear zone is 172 ± 6 km wide in the northernmost Walker Lane narrowing to 116 ± 4 km in the central Walker Lane. The total velocity budget across the shear zone is 7.2 ± 0.1 mm/yr in the north, increasing to 10.1 ± 0.1 mm/yr in the central Walker Lane. We conclude that assuming the presence of lower crustal dislocations when estimating geodetic faults slip rates may be inappropriate. Plain Language Summary: Interpreting Earth's surface deformation, measured by high‐precision GPS stations, is crucial for understanding plate tectonics and assessing seismic hazard. Traditionally, the assumption has been that faults in the Earth's upper crust extend as discrete dislocations into the lower crust. In this paper, we show that there is no compelling evidence of this in the Northern Walker Lane region of California and Nevada. Instead, the geodetically measured deformation on the surface reflects uniform shearing in the lower crust. Our findings suggest that estimating slip rates on the faults with methods that assume deep dislocations may be inappropriate. Instead, the slip rate of a fault is likely to be controlled by the fault's position and orientation within the shear zone. This has significant implications for seismic hazard assessment, as accurate estimates of slip rates on faults are a crucial component in determining seismic risk. Key Points: Geodetic velocities in the Walker Lane reflect distributed shear in the lower crust rather than deformation due to discrete faultsEstimating fault slip rates with models assuming their continuation into the lower crust may be inappropriate in the northern Walker Lane [ABSTRACT FROM AUTHOR]

The present study deals with the Fe–Ti oxides, rock magnetic and anisotropy of magnetic susceptibility (AMS) carried out to determine the magneto-mineralogical characteristics and the nature of the magnetic fabrics of the high-grade metamorphic rocks from Chilka Lake area, Eastern Ghats Mobile Belt (EGMB), India. Petrography depicted the presence of both primary and secondary magnetite and titano-magnetite as the chief magnetic minerals. Different generations of magnetite were found in these rocks corresponding to different conditions of temperature that prevailed during their oxidation, having tectonic implications depicting the crustal upliftment. Thermomagnetic analysis, isothermal remanent magnetization (IRM), hysteresis loops and backfield IRM demagnetisation show the presence of ferrimagnetic minerals of different origin. The magnetic domain is determined by Day plot, using the remanence and coercivity values from hysteresis curves, dominated by stable single domain (SSD), which reveals the potentiality to record the ancient magnetic field. AMS studies unravelled the nature of the magnetic fabrics in the region. The magnetic susceptibility ellipsoids are dominantly oblate as revealed from the Pj–Tj shape plots. The magnetic lineation is highly variable which states the multiple phased tectono-metamorphic conditions. The similarity between the magnetic and mesoscopic fabrics in the granulite is significant, whereas the anorthosites result from felsic magmatism, which occurred after the deformational phases and thus did not record any mesoscopic tectonic significance. [ABSTRACT FROM AUTHOR]

Hazards created by the landslide damming of rivers have become common in tectonically active mountainous areas. However, it remains unclear how tectonic effects may influence the formation and characteristics of landslide dams. The purpose of this paper is to explore how tectonic effects impact the drivers, geomorphic features, and activity characteristics of landslide dams along a fault zone. We investigated 83 landslide dams clustered along a fault zone in the Bailong River Basin. Most of the dams are located in areas of high tectonic stress, resulting from the rapid river incision and destruction of slope structure caused by intense tectonic activities in these areas. Statistical analysis, InSAR monitoring, and field investigation revealed that different tectonic effects were associated with significant differences in the geomorphic features, activity characteristics, and controlling factors of the landslide dams. Thus, we identified three distinct patterns of landslide dams in tectonically active mountainous areas: (1) Topography-driven landslide dams are caused by rapid rock uplift and river incision. Here, the steep terrain enhances the development of small landslides, the narrowness of the channels favors river damming, and the residual deposits on the hillslope remain active. (2) Tectonic activities promote the development of structural planes in the rock mass and reduce its strength, ultimately forming structural plane-controlled landslide dams. Although their volumes are not very large, the strong erosion resistance of rockslides can cause river damming and maintain the stability of deposits. (3) Fractured rock mass-controlled landslide dams are composed of broken rock and fault gouge. The extremely low strength of these materials allows them to form very large landslides that can easily dam the river, and maintain a slow-moving state. Through a geomorphological and geological model, our study offers new insights and enhances the understanding of the formation and characteristics of landslide dams induced by tectonic activity in mountainous regions. [ABSTRACT FROM AUTHOR]

Purpose. Detailed substantiation of the geological structure of the eastern edge of the Northern Ustyurt, clarification of modern geological and geophysical data, as well as highlighting the mainstages of evaluating the results of exploration work to confirm the oil and gas potential and subsequent exploitation of the fields. Methodology. The authors used the following scientific methods: generalization – to systematize scientific provisions; analogy and comparison – to characterize deflection in different periods; analysis and synthesis – to substantiate geological and geophysical data; algorithmmization – to determine conceptual provisions regarding the assessment of the oil and gas bearing capacity of the trough. Findings. In order to achieve the goals, the indicators of oil and gas capacity in the areas of the eastern side of the Northern Ustyurt of different geological ages were substantiated. The geological and geophysical features of the basin dating back to 2010 compared to modern refinement of geological data were characterized. The productive and unproductive structures of the eastern side of the Northern Ustyurt are characterized, taking into account the showing of oil and gas based on deposits of different geological ages. The importance of conducting geological exploration and creating corresponding cartographic materials is justified, followed by the design of predictive graphical models, geological sections, and a detailed plan of the territory. Originality. The influence of high hydro carbon generation rates on the further identification of “oil windows” has been substantiated for the first time. The hierarchical levels of predicting the oil and gas content of the trough are identified. The necessity of improving the mechanisms for assessing oil and gas content is substantiated. Practical value. The substantiation of the features of the assessment of the oil and gas content of the of the eastern edge of the Northern Ustyurt, which should be based on forecasting promising areas of prospecting, is the key to distinguishing between productive and unproductive objects, determining their real scale and directing investment flow precisely to promising areas with minimal environmental and economic losses. [ABSTRACT FROM AUTHOR]

Abstract Jurassic and Palaeocene tidal deposits of the epeiric Western Interior Sea in Wyoming, USA, differ significantly due to their contrasting climates and tectonic, geographic and depositional settings. Tidally generated, cross‐bedded sandstone bodies contained by incisions are common to both settings and can potentially be uncritically attributed to marine flooding of fluvial systems. Key differences in lithology, ichnology and relationships with surrounding sediment reveal fundamentally different depositional settings, however. The Jurassic system occupied a low accommodation, semi‐arid environment, with geographically open shorelines as relative sea‐level fell, creating an unconformable contact with the underlying, storm wave‐dominated shelf and shoreface deposits. Siliciclastic, intertidal flats formed adjacent to coastal aeolian and fluvial environments during brief turnarounds from the degradational (forced regressive) to aggradational and retrogradational (transgressive) system tract. Basinward of these environments, metre to decimetre‐scale cross‐bedded, bioclastic, subtidal compound dunes and tidal inlet complexes accumulated in areas of minimal clastic flux and within incisions created by submarine tidal currents. By contrast, the Palaeocene tidal systems formed in a high accommodation, subtropical setting, as rising sea levels forced the fluvial to marine transition zone landward and flooded coastal swamps, forming geographically irregular, back‐barrier complexes and tidally influenced fluvial systems. High volumes of siliciclastics, terrigenous organic material and freshwater were delivered by the rivers and created physicochemical stress on the marine embayments. Sandy tidal flat deposits accumulated in lagoons and interdistributary bays, but unlike the Jurassic examples, they do not mark a turnaround from the falling stage to the transgressive system tract. The potential preservation window for tidalites is significantly greater vertically in the aggradational to retrogradational setting than in the degradational system due to greater accommodation. The preservation window is vertically smaller, but areally greater in the Jurassic, forced regressive system because of basinward enhancement of tidal currents driven by complex palaeobathymetry caused by tectonic activity of local pre‐Laramide uplifts.

The aim of this study is to identify potential mineral deposits beneath the Southern Benue Trough of Nigeria based on apparent density mapping technique of estimating lateral rock densities from modelled gravity data. In this study, we apply the inverse density deconvolution filter to a short-wavelength gravity component in order to estimate the rock densities for mineral exploration applications and tectonic studies at the Southern Benue Trough in Nigeria. The estimated rock densities vary between 2.50 and 2.74 g/cm3, with minimum density values assigned to volcano-sedimentary deposits along the Cameroon Volcanic Line and maximum density values in the eastern and southern parts associated with mafic igneous rocks. Our gravity and density maps reveal the geometry of dominant geological structures within the study area. The density map highlights carbonate-hosted metallic elements with varying intercalations. Some of these identified mineralized zones coincide with locations of past and present producing mines. Intermediate and mafic igneous rocks as well as highly compacted and volcano-sedimentary rocks are mapped as rock-forming minerals for a mineral exploration. Hence, the obtained model of mineral-bearing rocks mainly demonstrates mechanisms of tectonic events, patterns of deformation regimes, and mineral prospectivity map of the study area.

Over the last 60 years, six landslides with volumes from 105 m3 to 5.3 × 107 m3 have occurred around Qwelqwelústen (Mount Meager Volcanic Complex; MMVC), southwestern British Columbia, Canada. The dormant volcanic massif has experienced significant uplift leading to exposed and incised Miocene and older basement rocks and volcanic rocks associated with the MMVC. The topographic relief and variation in rock types creates a complex environment where the interplay between lithology and landslide initiation can be captured. We developed models using logistic regression and random forest methods to assess the most critical parameters affecting inter-eruptive landslide susceptibility in the area. Both approaches indicate that Devastator Peak and Plinth Peak volcanic assemblages are of notably higher landslide susceptibility. Large landslides originated in higher areas, but long runout poses the main hazard. Results support the need for detailed geological mapping for landslide susceptibility assessments in elevated volcanic massifs worldwide.

The Mélange in Lamphun Province, situated in the southern region of the Chiang Mai-Chiang Rai Suture Zone (CMCRSZ), remains inadequately explored. This study employs field investigations and petrographic analysis to delineate the characteristics of the CMCRSZ Mélange, identifying nine distinct rock units. These units include Carboniferous quartz arenite interbedded with fine-grained sedimentary rocks, Permian lithic graywacke, Permian limestone hosting Pseudodaliolina sp. and Schwagerinid sp., Triassic chert containing Anisian radiolarian fossils, and ocean island basalt. This area exhibits complex folding and thrusting, accompanied by granitic intrusions and low-grade metamorphic rocks within a finer-grained sedimentary matrix. Stratigraphic assessments trace the primary material of the accretionary complex to the upper strata of the oceanic plate stratigraphy. Geochemical analyses indicate the mafic rocks as alkaline to subalkaline basalts, indicative of formation through an alkaline magma series, a conclusion supported by rare-earth element patterns. Sr/Nd isotope classification suggests ocean island tectonics for these rocks. The formation of the CMCRSZ Mélange occurred during the Paleo-Tethys oceanic crust subduction beneath the Indochina Terrane at the Permian-Triassic Boundary, accumulating diverse materials in a dynamically evolving tectonic context. Furthermore, S-type Triassic granites emerged post-collision during the Indosinian Orogeny following the thrusting of the CMCRSZ onto Sibumasu.

Statement of the general problem. The article provides an analysis of the geological and tectonic factors that influenced the formation of deposits of the Krosnenskaya zone of the Outer Carpathians. The authors considered several questions related to the stratigraphy and tectonics of this zone. In the geological structure of the Krosnenskaya cover, we distinguish two separate cover units - the Turkivskaya and Bitlyanskaya subcovers, based on their lithologic and facies characteristics. The problems of finding hydrocarbon deposits in this region are associated with an insufficient understanding of their structure. This problem was solved with the emergence of the concept of scaly-thrust structure of the Krosnenskaya zone. Productive horizons with unstable tides are revealed in the Oligocene sediments of Golovetsk. These horizons are not currently developed. We believe that it is possible to obtain stable industrial gas flows from such collectors. Research materials and methods. The history of the study of the geological structure of 7 deposits located on the territory of Poland and Ukraine within the considered and adjacent regions is presented: Borynskyi (well 1, 2), Hryniavskyi, Khaschiv-Lopushanskyi, Pobuk, Sanok, Strahotsina and Grabovnica. In total, 13 measurements of the composition of gas mixtures were included in the calculation. The depth range for the considered samples is within 875-5077 m, which allowed us to draw conclusions about changes in geochemical coefficients with depth. Presentation of the main research material. The analysis of the history of the evolution of organic matter was carried out using the method of geochemical coefficients and thermodynamic modeling using the methods of independent chemical reaction constants and entropy maximization. According to the results of the analysis, it was established that tectonic criteria directly affect thermobaric conditions, control the evolutionary processes of destruction of organic matter. We discovered that the source of gases in the deposits of the Krosnenskaya zone is only kerogen. On the other hand, part of the deposits of the zones adjacent to Krosnenskaya show deviations from this regularity, and we assume that part of the gases in these deposits are formed because of oil cracking. The article shows that the values of the i-C4/n-C4 coefficient vary slightly for the deposits of the considered region. Obviously, this indicates that the evolution of organic matter for the considered deposits took place in close conditions, both in terms of thermobaric conditions and in terms of the composition of the parent material. This conclusion is confirmed by the results of calculations of the formation depths of equilibrium gas mixtures both by entropy maximization and by the method of constants of independent chemical reactions. Conclusions. Geochemical analysis of kerogen depletion by the methane generation rate proved that the kerogen deposits of the region are not completely depleted and retain the potential for further evolution with the formation of hydrocarbon gases. Based on the above considerations, we believe that the oil and gas potential of this region has not been studied enough and requires additional analysis, including the laying of new exploratory wells.

The article is dedicated to the study of the art criticism views of the author of the first Russian textbook for students of the Imperial Academy of Arts, diplomat and Vice‐President of the Imperial Academy of Arts, Pyotr Petrovich Chekalevsky. In his essay A Discourse on Free Arts with a Description of Some Works by Russian Artists (1792), Chekalevsky mainly relies on J.J. Winckelmann, whose republican ideas do not repel him as a Russian aristocrat of the period of Catherine II and Paul I, but even arouse his warm sympathy. Chekalevsky sees the main reasons for the extinction of the arts of different countries and peoples in the despotism of state (for example, Rome of the Caesars’ era) and in the tyrannical power of money, depriving the artist of freedom, without which, according to Chekalevsky, full‐fledged artistic creativity is impossible. The death of art, according to him, can be avoided only if new Athens appears. Chekalevsky pays particular attention to the issues of artistic form, proving that a sculptor can express the idea of his work if he finds an artistic language corresponding to this idea. Meanwhile, the language of the sculptor is different from that of the painter, and confusion of different artistic languages (forms) leads, in a certain way, to empty talk, the loss of both content and form. According to Chekalevsky, it is architecture that requires the greatest creative ingenuity. Not only does he reconsider the ideas of classical art history independently and remaster them thoughtfully, but he also expresses them in the original Russian language. Chekalevsky’s utopia of the possibility of a new arts revival based on a certain republicanism in the conditions of the Russian enlightened absolutism predetermined the most progressive trends in the activities of the Imperial Academy of Arts, and his Discourse on Free Arts... can be called the first “living word” of Russian art studies. The textbook by Chekalevsky contains brief information about outstanding Russian sculptors, painters and architects of the second half of the 18th century.

The southeastward extrusion of Indochina along the Ailao Shan-Red River shear zone (ARSZ) is one of two of the most prominent consequences of the India-Asia collision. This plate-scale extrusion has greatly changed Southeast Asian topography and drainage patterns and effected regional climate and biotic evolution. However, little is known about how Indochina was extruded toward the southeast over time. Here, we sampled 42 plant and animal clades (together encompassing 1,721 species) that are distributed across the ARSZ and are not expected to disperse across long distances. We first assess the possible role of climate on driving the phylogenetic separations observed across the ARSZ. We then investigate the temporal dynamics of the extrusion of Indochina through a multitaxon analysis. We show that the lineage divergences across the ARSZ were most likely associated with the Indochinese extrusion rather than climatic events. The lineage divergences began at ~53 Ma and increased sharply ~35 Ma, with two peaks at ~19 Ma and ~7 Ma, and one valley at ~13 Ma. Our results suggest a two-phase model for the extrusion of Indochina, and in each phase, the extrusion was subject to periods of acceleration and decrease, in agreement with the changes of the India-Asia convergence rate and angle from the early Eocene to the late Miocene. This study highlights that a multitaxon analysis can illuminate the timing of subtle historical events that may be difficult for geological data to pinpoint and can be used to explore other tectonic events. [ABSTRACT FROM AUTHOR]

Through the examination of calcite twins, this research outlines the tectonic development and paleo stress patterns of the Paleozoic Routshon complex situated in the southeastern segment of the Sanandaj-Sirjan zone, a hinterland region of the Zagros orogeny in southeastern Iran. The study of orogenic phase indicates that the deformation event affecting the southern sector of the Sanandaj-Sirjan zone aligns with the Cimmerian orogenic phase of the Late Triassic period. A variety of structural features at both map and outcrop scales highlight the importance of slip partitioning in the structural evolution of this region, driven by inclined transpression. Observations suggest that the deformation related to contractional components includes steeply to moderately plunging folds, dipslip domain deformation primarily involving thrusts, and ongoing deformation by strike-slip component motion, which results in thrust-related ductile shear zones. The analysis of calcite c-axis fabrics from mylonite samples obtained from these shear zones indicates a low-temperature monoclinic pattern of non-coaxial deformation. This deformation type underscores the impact of the strike-slip component in the development of progressive simple shear within thrust-related shear zones in this segment of the Sanandaj-Sirjan zone. Dynamic analysis of caxis fabric data reveals a NE-SW orientation for the principal compressive axes (σ1) in this area. This direction, corroborated by additional data such as fault surface, GPS, and earthquake focal mechanism data, confirms that the orientation of the compressive axes (σ1) has remained consistent from the Late Triassic to the present. [ABSTRACT FROM AUTHOR]

Devonian successions in the Calliope and Yarrol provinces of the northern New England Orogen in central to northern Queensland have a lithological assemblage and depositional environments indicative of a close association with a subduction-related volcanic arc. These rocks have been interpreted as related to island arc and backarc settings based on geochemical characteristics of magmatic rocks. We present new detrital zircon ages from the Devonian to lower Carboniferous successions of the Calliope and Yarrol province successions. Most samples have no or relatively few zircon grains extracted except for samples of quartz-rich sandstone in the Middle Devonian Erebus beds of Hunter Island, located 160 km north-northwest of Rockhampton and another sample in the Rockhampton district. The samples with abundant zircon, and some with less common zircon, have prominent peaks of mid Cambrian to Ordovician ages and are consistent with derivation from the northern Thomson Orogen where igneous rocks of this age are documented in the Charters Towers Province. These data indicate a connection between the Devonian arc-flank deposits of the northern New England Orogen and the Thomson Orogen, which had previously been well established for Carboniferous deep-marine sandstones of the subduction complex (e.g. Shoalwater Formation). These results favour an east-facing continental margin arc setting in the Devonian contra to intra-oceanic island arc settings previously proposed. Detrital zircon age spectra from sampled early Carboniferous units of northern New England Orogen association indicate a pulse of felsic magmatism of that age. KEY POINTS: Devonian quartz-rich sandstones from the northern New England Orogen have abundant detrital zircon ages of mid Cambrian to Ordovician indicating a provenance connection with the Charters Towers Province of the northern Thomson Orogen. These results confirm a provenance linkage to Gondwana and imply that the Devonian tectonic setting was a continental margin arc and associated forearc basinal infill. Geochemical comparisons suggesting an island arc setting have overly influenced previous tectonic interpretations. [ABSTRACT FROM AUTHOR]

Obtaining geological and landform dislocation features, as well as the measured stratigraphic activity age, provides direct evidence to evaluate fault activity, which is more difficult to do in areas with low tectonic activity, such as eastern and central China. A detailed investigation of the fault activity, trenching, drilling joint geological profile, geological survey, and chronological analysis were used to obtain the spatial geometry, fault kinematics, and activity chronology of the Jiulong fault. The conclusions are as follows: (1) The Jiulong fault was a fracture zone composed of four branch faults, with a width of around 30–40 m and good extendibility, while the maximum surface rupture length was 373 m. (2) The Jiulong fault has many strata dislocations, and the dislocation distance decreased from bottom to top, demonstrating synsedimentary structure characteristics, with a maximum stratigraphic dislocation distance of 18.2 m. (3) Preliminary analysis suggested the Jiulong fault as a secondary fracture of the Xiangfan-Guangji fault zone and provided evidence of the southeastward extension of the Xiangfan-Guangji fault. A preliminary hypothesis purported the Xiangfan-Guangji fault as the seismogenic fault of the Ms 5.0 magnitude earthquake in 1911. (4) According to OSL and ESR dating analyses, the upper breakpoint of the Jiulong fault cuts into the Late Pleistocene Xingang Formation (Qp3x) strata, and the latest active age of the Jiulong fault was 57.6 ka. The chronology analysis confirmed an active fault from the Late Pleistocene and identified a weak tectonic in Jiujiang Province, which represents the largest active fault outcrop uncovered in the area so far. This study provides evidence and research materials for the evaluation of fault activity and seismic stability in this region. [ABSTRACT FROM AUTHOR]

Saturn's mid-sized icy moons have complex relationships with Saturn's interior, the rings, and with each other, which can be expressed in their shapes, interiors, and geology. Observations of their physical states can, thus, provide important constraints on the ages and formation mechanism(s) of the moons, which in turn informs our understanding of the formation and evolution of Saturn and its rings. Here, we describe the cratering records of the mid-sized moons and the value and limitations of their use for constraining the histories of the moons. We also discuss observational constraints on the interior structures of the moons and geologically-derived inferences on their thermal budgets through time. Overall, the geologic records of the moons (with the exception of Mimas) include evidence of epochs of high heat flows, short- and long-lived subsurface oceans, extensional tectonics, and considerable cratering. Curiously, Mimas presents no clear evidence of an ocean within its surface geology, but its rotation and orbit indicate a present-day ocean. While the moons need not be primordial to produce the observed levels of interior evolution and geologic activity, there is likely a minimum age associated with their development that has yet to be determined. Uncertainties in the populations impacting the moons makes it challenging to further constrain their formation timeframes using craters, whereas the characteristics of their cores and other geologic inferences of their thermal evolutions may help narrow down their potential histories. Disruptive collisions may have also played an important role in the formation and evolution of Saturn's mid-sized moons, and even the rings of Saturn, although more sophisticated modeling is needed to determine the collision conditions that produce rings and moons that fit the observational constraints. Overall, the existence and physical characteristics of Saturn's mid-sized moons provide critical benchmarks for the development of formation theories. [ABSTRACT FROM AUTHOR]

This study aims to investigate the intricate relationship between geological structures, water chemistry, and isotopic composition in order to gain a deeper understanding of the origins and recharge mechanisms of thermal–mineral waters in the Kyllini region. The research integrates tectonic analysis, hydrochemical data, and stable isotope measurements to delineate recharge zones and trace the origin of these unique water sources. The methods used for delineation are the geological and tectonic study of the area, as well as hydrochemical and isotopic data analysis. The findings highlight that tectonic activity creates preferential flow paths and consequently influences the hydrogeological framework, facilitating deep circulation and the upwelling of thermal waters. Monthly analyses of groundwater samples from the Kyllini thermal spring were conducted over one hydrological year (2019–2020) and compared with data from the area collected in 2009. The hydrochemical profiles of major and minor ions reveal distinct signatures corresponding to various water–rock interactions, while stable isotope analysis provides insights into the climatic conditions and altitudes of recharge areas. Hydrochemical analyses reveal the composition of thermal–mineral waters, aiding in the identification of potential sources and their evolution. The conceptualization of Kyllini contributes to the deeper understanding of the intricate interplay between tectonics, hydrochemistry, and stable isotopes. During a hydrological year, the water type of Kyllini's spring groundwater remains the same (Na-Cl-HCO3), presenting only slight alterations. [ABSTRACT FROM AUTHOR]

The folded Zagros is a part of the active Zagros belt in the southwest of Iran. This area has main faults and active rock formations, the activity of these faults has somehow affected the strata and sediments of different geological periods. In this study First, by studying satellite images and aerial photographs, five locations were selected in different parts of Fars and the hinterland of Bandar Abbas, and finally, the tectonostratigraphy of these locations was compared with each other. The sinology column and the paleogeographical map of these regions in the Miocene period were reconstructed Using the data obtained from five places of folded Zagros (Bastak, Bahar anticline, Arjan plain, Saadi mountain and Yasouj). The obtained results and the resulting diagrams were obtained using the RockWorks geological program. the minimum and maximum stratified thicknesses of the Miocene period formation in these five studied points are related to Arjan Plain and Saadi mountain sections By comparing the obtained results and the Hesar diagrams and the isopach map. It was done between the studied locations, which shows the highest thickness of this formation in the Arjan plain section and the lowest thickness is in Saadi Mountain. The facies changes of sedimentary rocks of the Miocene period seem to be due to the operation and activity of bedrock faults such as Kare Bes, Sabzpushan, Sarvestan and Kazeron faults in this region. [ABSTRACT FROM AUTHOR]

Diapir is a process in which material with a lower specific weight rises from the upper layers, breaks them, and appears on the surface of the earth. In this process, the type of salt's response to the applied stresses creates specific geomorphological forms, which study of such forms can be important due to the presence of oil resources, the establishment of human settlements, and the passage of communication routes. In this research, which was conducted with the aim of investigating the geomorphology caused by salt diapirs, in the south of Semnan privance and with field, library and Remote Sensing methods, it was found that salt deposits cause the creation of specific geomorphological structures and shapes through the creation of tension. local cracks, surface dislocations and tensile fractures. Also, the fluidity of salt has been created on the surface structures and their dimensions are effective, and these structures, in turn, create local forces and control the geomorphic structural situation of the region. In addition, the dissolution process has played an important role in the formation of salt karsts in the region and has created significant shapes. Based on this, the geomorphological formsresulting from the Salt diapirismof the region were identified and in three groups of building forms including salt domes, salt anticlines and salt walls, salt karsts including dolines, ponors, karns and forms resulting from hydrological processes including valleys, springs, salt fluxes and salt glaciers were classified. [ABSTRACT FROM AUTHOR]

Grabens, or valleys formed during extensional tectonic events, are common but rarely observed during formation. In November 2023, inelastic surface deformation formed abruptly along Iceland's plate boundary in Grindavík. We documented graben formation in real‐time through satellite mapping (InSAR), seismicity, GNSS data, repeated lidar surveys, and field mapping. Five normal faults and ∼12 fissures ruptured the surface delineating two grabens separated by a horst, a context not present in other contemporary case studies. The graben normal faults slipped rapidly (over hours) and maximum surface motions coincided with the occurrence of turbulent seismic swarms in both space and time. Although 3 eruptions took place ∼15 km northeast of Grindavík from 2021 to 2023, attributed to magma intrusions (i.e., dikes), none of these also formed grabens. Thus, the Grindavík grabens shows evidence for tectonic origins. Real‐time monitoring of these phenomena provide insight into graben formation on Earth and potentially on other planets. Plain Language Summary: Valleys known as grabens, typically caused by extensional tectonic events, are a common geological feature, yet their formation is rarely observed. In November 2023, such two grabens suddenly emerged along the boundary between tectonic plates in the town of Grindavík, Iceland. The grabens were shaped by tectonic activity expressed by a swarm of earthquakes and associated ground deformation and resulted in normal faults rupturing the surface and cutting through houses, linear infrastructure including water pipelines and roads within Grindavík. We document the grabens and horst in real time using satellite mapping (InSAR), geodetic GPS data, repeated drone surveys, field mapping, and seismic recordings from a local seismic network. The combination of these data provide unprecedented level of precision in characterizing surface and sub‐surface deformations, especially when maximum surface motions correlate with a turbulent seismic activity in both space and time. Critically, following the formation of the grabens, a series of intensive through short‐lived eruptions happened in December 2023, January 2024, February 2024, March, and May 2024 within the northernmost portion of the grabens. Our observations provide valuable insights into the natural laboratory of Iceland and contribute to the understanding of plate tectonics both on Earth and other planets. Key Points: The 2023 seismic swarm and extension lead to a graben forming that coincides in time and space along Iceland's plate boundaryDuring 2021 to December 2023 only one tectonic graben formed, although 4 eruptions have taken placeThe graben in Grindavík, Iceland is wider at the surface than most recently documented grabens (∼4,500 m vs. <1,000 m) [ABSTRACT FROM AUTHOR]

The creation of fractures in bedrock dictates water movement through the critical zone, controlling weathering, vadose zone water storage, and groundwater recharge. However, quantifying connections between fracturing, water flow, and chemical weathering remains challenging because of limited access to the deep critical zone. Here we overcome this challenge by coupling measurements from borehole drilling, groundwater monitoring, and seismic refraction surveys in the central California Coast Range. Our results show that the subsurface is highly fractured, which may be driven by the regional geologic and tectonic setting. The pervasively fractured rock facilitates infiltration of meteoric water down to a water table that aligns with oxidation in exhumed rock cores and is coincident with the adjacent intermittent first‐order stream channel. This work highlights the need to incorporate deep water flow and weathering due to pervasive fracturing into models of catchment water balances and critical zone weathering, especially in tectonically active landscapes. Plain Language Summary: The creation of fractures in bedrock facilitates water movement through the subsurface which breaks down rock creating porous soil and weathered bedrock. Water movement is vital for important processes like plant growth, streamflow, and groundwater recharge. However, understanding how fracturing, water flow, and rock weathering interact is challenging because the subsurface is difficult and expensive to measure. Here we use observations from drilling, water level monitoring, and geophysics to understand these interactions. Our results indicate that the subsurface is highly fractured due to the geologic and tectonic setting. The large number of fractures makes it easier for water to flow through the subsurface and causes chemical alteration of bedrock. This may cause water to flow outside of the catchment through the subsurface. This work highlights the role of geologic and tectonic processes in driving fracturing, which dictates the movement of water and subsurface weathering beneath Earth's surface. Key Points: Deep weathering may be due to enhanced permeability and surface area from inherited rock damage from local geologic and tectonic conditionsWeathering and water flow extend to the elevation of the adjacent first‐order intermittent stream channelThe deep weathering and fracturing front may allow for inter‐basin water flow in headwater catchments [ABSTRACT FROM AUTHOR]

The paper presents research results obtained during the exploration of copper and silver deposits on the southern rim of the Wolsztyn–Pogorzela High in terms of identification of the regional geological structure of Permian and Mesozoic sediments, with particular focus on tectonic zones. It discusses a new methodology of developing seismic and gravimetric data in the form of sections of effective reflection coefficients (ERC) and vertical gravimetric cross-sections, which in combination with borehole logging allowed for the identification or an update of the knowledge about regional tectonic zones which are missing from the maps of the sub-Zechstein substrate prepared to date. The discussion of the methodology uses the example of two tectonic zones: the Rawicz and Oleśnica grabens. Conversion of seismic sections into ERC cross-sections made it possible to trace strata of smaller thickness and facilitated the identification of low-amplitude dislocations. Vertical gravimetric cross-sections confirm the credibility of the interpreted faults and grabens, also showing whether the faults are deeply rooted. Historical geophysical materials developed in this manner constitute an important supplement to the identification of the geological structure of the Lower Silesian Basin and in particular, the tectonic zones which may provide ways of migration and circulation of solutions, as well as the ore generation zones. The collected materials may be used to supplement the structural and tectonic maps of the sub-Zechstein substrate in the Lower Silesian Basin, and the applied methodology and data analysis may be used in other regions of Poland. [ABSTRACT FROM AUTHOR]

Source‐to‐sink dynamics are subjected to complex interactions between erosion, sediment transfer and deposition, particularly in an evolving tectonic and climatic setting. Here we use stratigraphic forward modelling (SFM) to predict the basin‐fill architecture of a multi‐source‐to‐sink system based on a state‐of‐the‐art numerical approach. The modelling processes consider key source‐to‐sink parameters such as water discharge, sediment load and grain size to simulate various sedimentary processes and transport mechanisms reflecting the dynamic interplay between erosion in the catchment area, subsidence, deposition and filling of the basin. The Cenozoic succession along the SW Barents Shelf margin provides a key area to examine controls on source‐to‐sink systems along a transform margin that developed during the opening of the North Atlantic when Greenland and Eurasian plates were separated (ca. 55 Ma onwards). Moreover, the gradual cooling which culminated in major glaciations in the northern hemisphere during the Quaternary (ca. 2.7 Ma), has affected the spatio‐temporal evolution of the sediment routing along the western Barents Shelf margin. This study aims to characterize the relative importance of different source areas within the source‐to‐sink framework through SFM. In the early Eocene, the SW Barents Shelf experienced a relatively equal sediment delivery from three principal source areas: (i) Greenland to the north, (ii) the Stappen High to the east, representing a local source terrain, and (iii) a major southern source (Fennoscandia). In the middle Eocene, our best‐fit modelling scenario suggests that the northern and the local eastern sources dominated over the southern source, collectively supplying large amounts of sand into the basin as evidenced by the submarine fans in Sørvestsnaget Basin. In the Oligocene (ca. 33 Ma) and Miocene (ca. 23 Ma), significant amounts of sediments were sourced from the east due to shelf‐wide uplift. Finally, this study highlights the dynamic nature and controls of sediment transfer in multi‐source‐to‐sink systems and demonstrates the potential of SFM to unravel tectonic and climatic signals in the stratigraphic record. [ABSTRACT FROM AUTHOR]

Fluid‐induced seismicity has been a particularly emphasized mechanism over the last few years, especially after fluid‐related, moderate‐to‐large earthquakes have been observed in several locations around the globe. Several studies suggest that the relationships between seismicity and fluid presence are related to variations in the stress state of rocks, due to the increase or drop of the pore fluid pressure. In this scenario, the Val d'Agri represents a precious case study where fluid‐induced seismicity is observed. In this area, two seismic clusters are observed in the Apulian Carbonate Platform, caused by (a) wastewater reinjection that reactivated the Costa Molina Fault blind thrust, and (b) seasonal water loading from the Pertusillo reservoir. The mechanisms behind these reactivated faults' evolution are still uncertain, especially in the compressive/extensional tectonic setting characterizing the area's evolution. Consequently, the distribution of the seismic potential in the region is largely unconstrained. We constructed a numerical thermo‐mechanical model to identify the main mechanisms that promoted the Val d'Agri present‐day tectonic setting and to assess the seismic hazard characterizing this region. We show that deformation within the Sedimentary Cover and the Crystalline Basement decoupled along a major décollement layer, represented by the Triassic Burano Formation. We also estimate the Coulomb stress (σC) in the region, assessing the crust's potential to generate earthquakes. Our results suggest that σC > 0 in a large part of the crust, and therefore that fluid injection may be particularly effective for the reactivation of buried structures, especially at a depth between ≃2 and ≃6 km. Plain Language Summary: Fluids are one of the elements that can generate seismicity. The Val d'Agri is one of the regions where the injection of wastewater at depth in the subsurface caused the generation of low‐magnitude earthquakes in the proximity of the Costa Molina well, while the presence of the Pertusillo Lake led to further seismic activity in the SW area of the valley. This seismicity is generated along faults whose geometry and evolution are still a matter of debate. One of the consequences of this uncertainty is that the seismic hazard that characterizes the Val d'Agri and surrounding regions is not very well constrained. Therefore, we built up a numerical model that identifies the factors leading to the present‐day fault configuration and activity in the area. In addition, we provide an estimation for the potential seismic hazard that characterizes the Val d'Agri. We show that the Val d'Agri configuration is largely due to a decoupled deformation of the sedimentary cover with respect to the crystalline basement. In addition, stress field estimations in the region suggest that the Val d'Agri is a high seismic hazard area, where fluid‐related human activities in the subsurface should be carried out with caution. Key Points: We propose a numerical thermo‐mechanical model to identify the mechanisms that promoted the present‐day Val d'Agri tectonic settingThe presence of a décollement layer and reactivation of preexisting faults are key factors for generating seismically active structuresThe Val d'Agri crust stress state indicates the presence of critically stressed faults where fluid pressure increase may trigger seismicity [ABSTRACT FROM AUTHOR]

The onset of the Cossato-Mergozzo-Brissago shear zone within the Strona Ceneri Border Zone in the W-Southalpine basement (Italy) and its role in the collapse of the Variscan crust have been the subject of considerable controversy. A set of new petrographic, geochemical and geochronological data from a suite of syn-kinematic migmatitic paragneiss and amphibolites in between the upper and lower crustal sections of the W-Southalpine basement provide new evidence on the thermo-mechanical role played by the middle crust in the evolution of the Permian Southalpine basement. The petrological investigation of these amphibolite-facies rocks and U–Pb ages from monazite crystals, occurring in distinct microstructural positions, provide new P–T-t constraints on the late-Paleozoic tectono-thermal evolution of the Variscan middle crust. The SCBZ units recorded tectonic events from a possible Early Silurian Cenerian (ca. 440 Ma) overprint onto the proto-sedimentary units of the Southalpine basement to the Mid-Permian (ca. 285 Ma) syn-kinematic partial melting event developed close to the CMB shear zone. Phase equilibria modeling is used to constrain the metamorphic conditions recorded by this section of the Variscan basement. Pressure–temperature (P–T) isochemical phase diagrams show that, after the ca. 330 Ma Variscan metamorphic peak at P ≅ 4 kbar and T < 630 °C, the SCBZ paragneiss experienced isobaric heating up to 700–720 °C at ca. 285 Ma, which led to the formation of a syn-kinematic partial melting event coeval to the emplacement of the Mafic Complex in the lower Ivrea-Verbano Zone. These new geochronological and petrological constraints on the SCBZ paragneiss seem to corroborate the hypothesis that the transition from the stage of mature Variscan orogen to the stage of its collapse developed in the Permian, at ca. 285 Ma. Thus, we argue that the orogenic collapse was probably driven by the rheological weakening of the mid-crustal SCBZ units induced by their syn-tectonic partial melting and, ultimately, by the coeval thermal perturbation of the crust due to the intrusion of the mafic igneous suite at the crust-mantle boundary. [ABSTRACT FROM AUTHOR]

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

Various types of Global Navigation Satellite System (GNSS) data are used for a wide range of applications. When modeled correctly, millimeter precision daily GNSS position time‐series yield velocities and other derived products that can be used for investigations of lithospheric processes and properties. In this review paper, we describe the specific types of GNSS data and data products that are valuable for studies of the lithosphere, such as coseismic offsets, post‐seismic decay in time‐series, seasonal signals, secular velocities, and strain rates, and how those data are derived. We also discuss the applications of several types of GNSS data and data products. We provide open access resources for precision GNSS daily position time‐series, quality secular velocity solutions, and daily GNSS RINEX files for researchers interested in processing their own data. Plain Language Summary: Measurements of how the surface of the Earth moves can be made with millimeter precision using Global Navigation Satellite System (GNSS) data. Several different types of GNSS‐derived data can be used to study the relatively rigid outer layers of the Earth known as the lithosphere. In this review paper, we detail how GNSS data that are relevant for lithospheric studies are determined, including what corrections and errors must be considered. We describe several applications of certain GNSS data, such as quantifying tectonic plate motions. At the end of the paper, we provide numerous open access resources for GNSS data and data products that are valuable for studies of the Earth's lithosphere. Key Points: Describe various types of Global Navigation Satellite System (GNSS) data and their uses for studying the lithosphereReview of the treatment of GNSS data required for lithospheric studiesProvide information about numerous open access GNSS data resources [ABSTRACT FROM AUTHOR]

High‐relief glacial valleys shape the modern topography of the Southern Patagonian Andes, but their formation remains poorly understood. Two Miocene plutonic complexes in the Andean retroarc, the Fitz Roy (49°S) and Torres del Paine (51°S) massifs, were emplaced between 16.9–16.4 Ma and 12.6–12.4 Ma, respectively. Subduction of oceanic ridge segments initiated ca. 16 Ma at 54°S, leading to northward opening of a slab window with associated mantle upwelling. The onset of major glaciations caused drastic topographic changes since ca. 7 Ma. To constrain the respective contributions of tectonic‐mantle dynamics and fluvio‐glacial erosion to rock exhumation and landscape evolution, we perform inverse thermal modeling of a new data set of zircon and apatite (U‐Th)/He from the two massifs, complemented by apatite 4He/3He data for Torres del Paine. Our results show rapid rock exhumation recorded only in the Fitz Roy massif between 10 and 8 Ma, which we ascribe to local mantle upwelling forcing surface uplift and intensified erosion around 49°S. Both massifs record a pulse of rock exhumation between 7 and 4 Ma, which we interpret as enhanced erosion during the beginning of Patagonian glaciations. After a period of erosional and tectonic quiescence in the Pliocene, increased rock exhumation since 3–2 Ma is interpreted as the result of alpine glacial valley carving promoted by reinforced glacial‐interglacial cycles. This study highlights that glacial erosion was the main driver to rock exhumation in the Patagonian retroarc since 7 Ma, but that mantle upwelling might be a driving force to rock exhumation as well. Plain Language Summary: The isotopic system (U‐Th)/He in apatite and zircon record the ages in which a rock experiences relatively low temperatures (200–60°C) at shallow crustal depths (6–1 km). We present a new data set of low‐temperature thermochronometers for rocks of the Fitz Roy and Torres del Paine mountains in the Southern Patagonian Andes. Fast rock cooling can be forced by intensified surface erosion, and/or tectonic and mantle activity. An episode of fast cooling between 10 and 8 Ma was identified in the Fitz Roy mountains, and mantle upwelling forcing surface uplift, combined with high fluvial erosion may have caused fast rock exhumation. A regional episode of fast rock cooling between 7 and 4 Ma causing 1–3 km of exhumation in the Fitz Roy and Torres del Paine is coincident with the onset of Patagonian glaciations, which would have enhanced erosion and, thus, rock exhumation. An episode of fast rock cooling in the Quaternary is recorded in Torres del Paine rocks, interpreted as enhanced fluvio‐glacial erosion during the Plio‐Pleistocene climate transition toward faster glacial/interglacial cycles. Therefore, we were able to quantify separately the effects of tectonics and climate changes on rock exhumation, what is usually difficult due to simultaneously occurring processes. Key Points: Mantle upwelling in Southern Patagonia is the most likely mechanism forcing rock exhumation between 10 and 8 Ma in the Fitz Roy massifApatite (U‐Th)/He data reveal glacial erosion as the main driver to the exhumation of the Fitz Roy and Torres del Paine between 7 and 4 MaApatite 4He/3He data reveal intensified fluvio‐glacial erosion in Torres del Paine as a result of the Plio‐Pleistocene climate transition [ABSTRACT FROM AUTHOR]

West Africa continues to host a growing number of low and intermediate‐magnitude earthquakes (M2‐5) along its passive margins, and its continental interior. Earthquake activity in these regions raises the need to comprehend the causes and the tectonic controls of the seismicity. Unfortunately, such studies are rare. Here, we apply single‐station inversion techniques to constrain fourteen focal mechanisms, computed after compiling a set of high‐quality waveforms. We describe the connection between seismicity, the contemporary stress field, anthropogenic activity and Holocene fault scarps in the region. Our results indicate transpressive stresses acting on the inherited brittle structures in the passive margins. We also observe a compressive regime in the intracontinental failed rifts. We attribute the seismicity to the reactivation of "weak" faults in the Neoproterozoic and Mesozoic failed rifts, the passive transform structures, and the intracratonic Precambrian brittle shear zones. Plain Language Summary: Earthquakes have occurred in West Africa, in the interior and the edges of regions that host several brittle structures. The causes and the mechanisms of this seismicity have not been comprehensively investigated. Hence, the characteristics of the regional tectonics are not fully established. In this study, we resolve the properties of the source of earthquakes, and the regional stress field. Our description of the sources of earthquakes matches the geometry of inherited brittle shear zones and failed rifts. The results indicate a strong influence of transpressive stress transfers from the ocean to the passive margins of West Africa. In the continental interior, especially, the West African Belt, the stress is compressional in the E‐W direction, consistent with stress orientations in adjoining regions. An extensional earthquake is observed in Mali, within the Gourma failed rift. We find that the seismicity of West Africa and the variations of the stress can be explained by the combination of preexisting faults, plate forces, ocean‐continent stress transfer, and density heterogeneity across the geologic domains. Key Points: Improved constraints on stress regimes and stress orientations from inversion of new focal mechanisms of M < 5.5 earthquakesNew focal mechanisms obtained from classical and novel approach based on single station waveform inversionEarthquakes in West Africa are rupturing the passive margin faults, intracontinental failed rift faults, and brittle shear zones [ABSTRACT FROM AUTHOR]

The Central German realm is characterised by heterogeneous and complex structures within the pre-Cenozoic substratum. Many narrow fault zones separate domains that are very little deformed. Moreover, also wide large-wavelength and low-amplitude anticlines formed that are associated with the migration of thick evaporite and salt layers of the Zechstein (Late Permian). This complex structural setting is the result of multiple phases of tectonic deformation. During the Late Palaeozoic, the metamorphic basement deformed during the Variscan Orogeny became separated into local grabens and pullapart basins. Subsequently, latest Palaeozoic (Upper Rotliegend and Zechstein) and Mesozoic strata were deposited in an intracontinental basin system, the so-called Central European Basin System of which the North German Basin is its central part. However, several tectonic events intermitted a general uniform sedimentation. First, Late Triassic extension localised along few fault zones (e.g. the Allertal Fault Zone), where large offsets are documented within the Mesozoic stratigraphic pile. Late Jurassic-Early Cretaceous extension affected large parts of Central Europe, where deformation became more distributed and multiple NW-SE trending fault zones with a uniform spacing evolved (e.g. the Halberstadt Fault and the Offleben- Oschersleben-Staßfurt Fault). The last Mesozoic tectonic event in the Central German realm was characterised by Late Cretaceous shortening, which led to uplift of large basement-cored anticlines (e.g. the Harz Mountains and the Flechtingen High located south and north of the Subhercynian Basin, respectively) as well as to thin-skinned thrusts and anticlines in the forelands of basement uplifts. During all these events, a certain amount of halokinetic movements must be assumed for the Central German realm. [ABSTRACT FROM AUTHOR]

The atypical Tien Shan and Carpathians flysch is compared and correlated to recognize the local (regional) and general (inter-regional) peculiarities of its structure and place in the evolution of mobile belts. The objects of study include the Upper Carboniferous flysch of the Khanaka Syncline (Tien Shan) and Upper Eocene flysch of the Podhale Syncline (Carpathians). Flysch of the Khanaka and Podhale synclines is compared for the first time using the historical–geological analysis based on the study of lithostratigraphy, tectonic structure, and geodynamic setting of objects. The objects of study belong to different mobile belts and tectonic cycles, but they are similar in internal structure and tectonic setting atypical of flysch and exhibit some features atypical of flysch: the formation on a quasiplatform basement, a significant volume of conglomerates, a simple configuration of geological bodies, an absence of internal deformations, and a narrow temporal period of formation. It follows from the comparative analysis that the studied objects belong to a specific flysch type that we suggest naming the final flysch of rear blocks of the mobile belts, whose formation reflects the specific geodynamic evolution of the Hercynian and Alpine mobile belts. [ABSTRACT FROM AUTHOR]

We evaluate seismicity and tectonics along the San Andreas Fault (SAF) in southern California to elucidate ongoing near‐field crustal deformation processes. The principal slip surfaces (PSSs) or the fault core that accommodate major earthquakes, form the boundary between the tectonic plates. We analyze seismicity catalogs extending back to 1857, 1932, and 1981 with progressively improved magnitude of completeness and spatial resolution. The 1857 to present statewide catalog that is complete at M5.5+ documents minimal aftershock activity for the Mw7.9 1857 and 1906 Mw7.8 San Francisco earthquakes. The higher quality 1932 and 1981 catalogs show that the PSSs (the rupture zone) of the 1857 Mw7.9 Fort Tejon earthquake exhibits remarkable seismic quiescence both in the core and in the adjacent extended‐damage zone. Further south, the fault core is still aseismic but the shape of the SAF is more complex, and the rate of adjacent seismicity is much higher. This fault complexity and the seismicity rate are larger the more the strike of the SAF deviates from the Pacific plate velocity‐vector direction. The focal mechanisms of the SAF adjacent earthquakes are also heterogeneous and rarely have strikes and dips that are consistent with slip on the nearby PSSs. We infer that the southern SAF is locked, and a lack of seismicity at the core of the fault may be a standard feature of faults that almost exclusively accommodate high‐slip rates by producing major earthquakes. Correspondingly future aftershock sequences of major earthquakes on the southern SAF will likely have below average aftershock productivity. Plain Language Summary: The fast‐moving San Andreas Fault (SAF) that runs up the spine of California from the Salton Sea to Cape Mendocino, forms the plate boundary between the Pacific and North America plates. It has accommodated California's two largest earthquakes, the 1857 Mw7.9 Fort Tejon and the 1906 Mw7.8 San Francisco, which ruptured the fault for hundreds of kilometers. We focus on analyzing the seismicity of the southern SAF from 1857 to present. Almost no small earthquakes occur along the core of the southern SAF, from south of Parkfield to the Salton Sea. To the north, the 1857 Mw7.9 earthquake was followed by relatively few immediate aftershocks, and since 1932 this section of the fault has been very seismically quiescent. To the south of the 1857 rupture, the rate of extended‐damage zone seismicity inversely correlates with the SAF strike deviation from the Pacific plate vector relative to the SAF strike. In particular, the east‐west striking 28 km long Mill Creek segment may impede SAF slip, which results in abundant off‐fault seismicity and transfer of tectonic strain into the eastern California shear zone and the Peninsular Ranges. Key Points: The near‐field seismicity of the southern San Andreas Fault (SAF) is limited to the adjacent extended‐damage zone and mostly absent from the fault coreStep changes in the 95% depth and in the texture of seismicity depth distribution likely define the presence of the SAF fault coreSeismicity rate in the damage zone positively correlates with SAF deviation from Pacific plate vector except in the quiescent 1857 rupture [ABSTRACT FROM AUTHOR]

The Mongol-Okhotsk Ocean, which has been closing gradually from the west to the east beginning since the Late Paleozoic, was an important part of the Central Asian Orogenic Belt. It influenced the tectonic framework of Northeast Asia in the Mesozoic, especially the Late Mesozoic arc-basin system that is widely distributed in the Great Xing'an Range. However, the manner in which the Mongol-Okhotsk Ocean affected the sedimentary basin development remains poorly understood. To address this issue, we conducted U-Pb dating of detrital zircon deposited sedimentary basins of the central Great Xing'an Range. By examining the possible provenances of the detrital zircon and the structural controls of the basins, we found that a key sedimentary unit was deposited around Late Jurassic-Early Cretaceous. Its provenance was a felsic source in a back-arc setting of an active continental margin. The findings also suggest the existence of a unified geodynamic setting that affected the coeval development of basins in the northern Great Xing'an Range and the Yanshan fold-thrust belt along the northern margin of North China Craton. This research helps to better understand the complex tectonic processes which shaped the Northeast Asia during the Late Mesozoic. [ABSTRACT FROM AUTHOR]

Anatolia is the global archetype of tectonic escape, as witnessed by the devastating 2023 Kahramanmaraş Earthquake sequence, and the 2020 Samos Earthquake, which show different kinematics related to the framework of the escape tectonics. Global Positioning System (GPS) motions of the wedge-shaped plate differ regionally from northwestwards to southwestwards (from east to west). Anatolia was extruded westward from the Arabian-Eurasian collision along the North and East Anatolian fault systems, rotating counterclockwise into the oceanic free-faces of the Mediterranean and Aegean, with dramatic extension of western Anatolia in traditional interpretations. However, which is the dominant mechanism for this change in kinematics, extrusion related to the Arabia/Eurasia collision or rollback of the African slab beneath western Anatolia is still unclear. To assess the dominant driving mechanisms across Anatolia, we analyze recent GPS velocity datasets, and decomposed them into N-S and E-W components, revealing that westward motion is essentially constant across the whole plate and consistent with the slip rates of the North and East Anatolia fault zones, while southward components increase dramatically in the transition area between central and western Anatolia, where a slab tear is suggested. This phenomenon is related to different tectonic driving mechanisms. The Arabia-Eurasia collision drives the Anatolian Plate uniformly westwards while western Anatolia is progressively more affected by the southward retreating African subducting slab west of the Aegean/Cypriot slab tear, which significantly increases the southward component of the velocity field and causes the apparent curve of the whole modern velocity field. The 2020 and 2023 earthquake focal mechanisms also confirm that the northward colliding Arabian Plate forced Anatolia to the west, and the retreating African slab is pulling the upper plate of western Anatolian apart in extension. We propose that the Anatolian Plate is moving westwards as one plate with an additional component of extension in its west caused by the local driving mechanism, slab rollback (with the boundary above the slab tear around Isparta), rather than separate microplates or a near-pole spin of the entire Anatolian Plate, and the collision-related extrusion is the dominant mechanism of tectonic escape. [ABSTRACT FROM AUTHOR]

Crossing conjugate normal faults (CCNFs) are extensively developed in many hydrocarbon-producing basins, generally existing in the form of incomplete CCNFs. Nevertheless, the effect of the non-conjugate zone of the CCNFs on the conjugate relay zone post late tectonic action has not been previously studied. We use 3D elastic-plastic modeling to investigate the influence of incomplete (i.e., partially intersecting) CCNFs on the pattern of deformation of strata in the intersection region. A series of model simulations were performed to examine the effects of horizontal tectonic extension, fault size, and fault depth on the deformation of conjugate relay zones of incomplete CCNFs. Our analyses yielded the following results. (1) The model of incomplete conjugation predicts a convex-up style of deformation in the conjugate graben region superimposed on overall subsidence under applied horizontal tectonic extension. (2) The degree of convex-up deformation of the conjugate graben depends on the influence of the non-conjugate zone on the conjugate relay zone, which varies with the amount of horizontal tectonic extension, fault size, and fault burial depth. (3) Our results indicate that incomplete CCNFs can form convex-up deformation, similar to that in the Nanpu Sag area and provide a sound understanding of hydrocarbon migration and accumulation. [ABSTRACT FROM AUTHOR]

Strain localization processes in the continental crust generate faults and ductile shear zones over a broad range of scales affecting the long-term lithosphere deformation and the mechanical response of faults during the seismic cycle. Seismic anisotropy originated within the continental crust can be applied to deduce the kinematics and structures within orogens and is widely attributed to regionally aligned minerals, e. g., hornblende. However, naturally deformed rocks commonly show various structural layers (e.g., strain localization layers). It is necessary to reveal how both varying amphibole contents and fabrics in the structural layers of strain localization impact seismic property and its interpretations in terms of deformation. We present microstructures, petrofabrics, and calculate seismic properties of deformed amphibolite with the microstructures ranging from mylonite to ultramylonite. The transition from mylonite to ultramylonite is accompanied by a slight decrease of amphibole grain size, a disintegration of amphibole and plagioclase aggregates, and amphibole aspect ratio increase (from 1.68 to 2.23), concomitant with the precipitation of feldspar and/or quartz between amphibole grains. The intensities of amphibole crystallographic preferred orientations (CPOs) show a progressively increasing trend from mylonitic layers to homogeneous ultramylonitic layers, as indicated by the JAm index increasing from 1.9–4.0 for the mylonitic layers and 4.0–4.8 for the transition layer, to 5.1–6.9 for the ultramylonitic layers. The CPO patterns are nearly random for plagioclase and quartz. Polycrystalline amphibole aggregates in the amphibolitic mylonite deform by diffusion, mechanical rotation, and weak dislocation creep, and develop CPOs collectively. The polymineralic matrix (such as quartz and plagioclase) of the mylonite and the ultramylonite deform dominantly by dissolution-precipitation, combined with weak dislocation creep. The mean P and S wave velocities are estimated to be 6.3 and 3.5 km/s, respectively, for three layers of the mylonitic amphibolite. The respective maximum P and S anisotropies are 1.5%–6.4% and 1.8%–4.5% for the mylonite layers of the mylonitic amphibolite, and 6.0%–6.9% and 4.5%–5.0% for the transition layers; but for the ultramylonite layers, these values increase significantly to 8.0%–9.1% and 5.1%–6.0%, respectively. Furthermore, increasing strain (strain localization) generates significant variations in the geometry of the seismic anisotropy. This effect, coupled with the geographical orientations of structures in the Hengshan-Wutai-Fuping complex terrains, can generate substantial variations in the orientation and magnitude of seismic anisotropy for the continental crust as measured by the existing North China Geoscience Transect. Thickened amphibolitic layers by extensively folding or thrusting in the middle crust can explain the strong shear wave splitting and the tectonic boundary parallel fast shear wave polarization beneath the Hengshan-Wutai-Fuping complex terrains. Therefore, signals of seismic anisotropy varying with depth in the deforming continent crust need not deduce depth-varying kinematics or/and tectonic decoupling. [ABSTRACT FROM AUTHOR]