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An investigation into tectonics and erosion reveals that they play an important role in causing uplifting, valley incision, and soil erosion. The analysis of drainage basins at different scales is irreplaceable in the development of sustainable plans, particularly in arid regions. Morphotectonics and morphometric characterization analyses are very effective methods for defining the evolution of different landforms, current-day tectonic activity, and hydrological and morphological signatures of basins under investigation. The reorganization of critical drainage basins and sub-basin risk priority ranking are essential for effective and accurate sustainable plans for drainage basin management and water resources. In this study, the coupling of geospatial techniques and statistical strategies was used to examine the tectonic activity and priorities in terms of soil erosion for 15 sub-basins of Wadi Al-Lith along the Red Sea coast of Saudi Arabia. Two effective models, namely, the relative tectonic activity model and the weighted sum analysis model, were applied for examining each geomorphological and hydrological characteristic based on an analysis of the morphotectonics and morphometric parameters. Regarding the relative tectonic activity model, the 15 sub-basins were classified into three classes of tectonic activity: low, moderate, and high. Sub-basins 5, 6, 13, and 15 were considered to be in class 1 (high relative tectonic activity). On the other hand, the weighted sum analysis model assigned the sub-basins into three different ranks: low-, moderate-, and high-soil-erosion priorities. The current study’s results suggest that sub-basins 5, 6, 10, 13, and 15 were recorded within the high-soil-erosion zone and highly relative tectonic activity, covering approximately 53.52% of the total sub-basin areas. The relative tectonic activity and weighted sum analysis models proved their validity in the risk studies, which will be very useful for decision makers in various fields, including natural resources and agriculture.

The Lumuwang Formation in Hainan Island is a key stratum for analyzing Mesozoic tectonic evolution. However, its depositional age relies only on sporopollen evidence, lacks high-precision dating, and its age attribution remains controversial. Additionally, the origin, tectonic setting of its volcanic interlayers and their connection to regional magmatic activities are unclear, which greatly restricts the systematic understanding of Hainan Island's Mesozoic paleogeography and geotectonic evolution. Targeting a newly discovered set of volcanic rocks hosted in the terrigenous clastic rocks of the Lumuwan Formation in Haitangwan Town, Sanya City, this study systematically conducted zircon U-Pb dating and geochemical analysis. The results show that the minimum age is 121 Ma, thereby accurately constraining the depositional age of the clastic rocks of the Lumuwan Formation to the Early Cretaceous. Geochemical characteristics indicate that the volcanic rocks belong to the high-K calc-alkaline to shoshonitic series. Their low Mg# values and high MF and DI values indicate that the magma underwent highly differentiated evolution. The rare earth element (REE: La-Lu) distribution shows significant enrichment of light rare earth elements (LREE: La-Eu) and strong fractionation between LREE and heavy rare earth elements (HREE: Gd-Lu). Trace elements are characterized by enrichment of large ion lithophile elements (LILE: Rb, Ba, and K) and depletion of high field strength elements (HFSE: Nb, Ta, and Ti), highlighting typical island arc magma attributes. The above geochemical characteristics of the volcanic rocks reveal that the study area was in a transitional tectonic environment from an island arc to back-arc extension during the Early Cretaceous. This provides key empirical evidence for the dynamic process of the transition from a continental margin arc to intracontinental extension around 121 Ma in the South China continental margin, further deepening the scientific understanding of Mesozoic crust-mantle interaction and basin-mountain coupling processes in Hainan Island.

Western Anatolia is one of the most rapidly extending and seismically active regions in the world. The circa N-S extension since the Early Miocene caused the formation of E-W trending major grabens and intervening horsts, having earthquake potentials with magnitude ≥5. The E-W oriented Büyük Menderes graben cross-cuts the broadly N-S oriented Bozdoğan and Karacasu grabens, of which the boundary faults of the latter are the source of seismic activity. Geomorphic indices, including drainage basin asymmetry, mountain front sinuosity, valley-floor width to valley height ratio, stream length-gradient index and normalized channel steepness index, were used to evaluate the boundary fault segments of the Bozdoğan and Karacasu grabens. The results indicate that both grabens are tectonically active and therefore regions of earthquake potential, consistent with the epicenters of earthquakes. Thus, it can be inferred that fault segments of second-order grabens, which are crosscut by the boundary faults of seismically active main depressions, are apparently reactivated by ongoing tectonism and may represent seismic activity. This suggestion applies also for similar basins located in the western Anatolia.

The Dniester valley is a spectacular example of a degrading bedrock fluvial system at the contact between the East European platform and the Carpathian orogen. This study is based upon a combined lithofacies–architecture–morphological study. The complex approach replaces an erstwhile conventional pure geomorphological one, eliminating the shortcomings and inaccuracies, providing a more justified stratigraphy and extended version of the valley evolution. The history of the valley and associated fluvial systems (alluvial fans, delta, coastal alluvial plains) occurred at the end of the Miocene and continued through the Pliocene-Quaternary (11–12 Myr). It unfolded against the background of the retreat of the Eastern Paratethys sea, including the ‘foreland’ and ‘cratonic’ periods and their seven stages. The spatial organization of the river’s drainage networks, sedimentary environments, fluvial styles and landforms changed gradually during these intervals and experienced rapid reorganization when they were replaced. All this left characteristic features within the valley’s four established plain reaches. The tectonic control on these changes through flexural deformation and accelerated uplift/tilt within the platform was decisive while the impact of climatic changes remained problematic. The issues of the river terraces correlation, base-level oscillations, influence of the rock’s erodibility and non-fluvial processes are also considered.

The significant Shillong earthquake of 1897 in the western part of the Shillong Massif profoundly impacted the entire Northeast India region, resulting in extensive devastation at both surface and subsurface levels. Numerous land fissures, sand veins, swampy areas, and land tilting and upliftment were formed during the earthquake in the western part of the Shillong plateau. This study adopts an integrated approach, combining seismic, geophysical, and fluvial geomorphology methods, to quantify the co-seismic subsurface rupture. Multichannel Surface Wave Analyzer (MASW) and resistivity surveys are conducted at fourteen locations along three profiles crossing the Krishnai and Chedrang Rivers in the Chedrang valley. In certain specified locations, significant surface rupture is observed, and the co-seismic surface uplift is measured to be 5 + 1 m on vertical planes at the western end of the rupture of the Oldham fault. The shear wave velocities along the profiles range from 184 to 466 m/s, indicating a platform for intense shallow seismicity triggered by fracture. The region experiences intense seismic activity, with the bottom of the seismogenic zone estimated to be 40 km, mainly dominated by thrust with strike-slip components. The local stress pattern in the Chedrang valley, oriented NE-SW, differs from the regional stress pattern, NNW-SSE, indicating the influence of geodynamic controls. Fluvial-morphometric measurements of the Krishnai and Chedrang Rivers for six different stretches in each case during 1964, 1991, and 2014 reveal a westward shifting of the Krishnai River ranging from 190 to 269 m, while the Chedrang River exhibits variable south-westward avulsion along these stretches, shifting approximately 132–312 m. Detailed fluvial morphological mapping highlights a key site where the stratigraphy of the fault scarp, reaching a height of 13ft, indicates the presence of modern channels, colluviums, gravel, and pebble beds with sand lenses, representing a portion of a mega thrust event. Simultaneously, high-resolution topographic profiles are analyzed using Total Station (GPS based) to observe co-seismic surface uplifts induced by the 1897 earthquake. The simplest deformation model suggests that a majority of the intra-seismic elastic loading east of the Krishnai and Chedrang rivers was uplifted during the 1897 earthquake due to co-seismic and post-seismic rupture, primarily in the western part of the Shillong plateau beneath the Chedrang valley. This energy transfer affected the north–south direction of the Krishnai valley, where the Krishnai river and the 'Mori' (dead) Krishnai river exist, as evidenced by subsurface deformation and subsequent avulsion of the Krishnai river. The parameters investigated in this study contribute to a better understanding of the geodynamics and seismic hazard assessment of the region, providing valuable insights into the consequences of the 1897 earthquake and its implications for future seismic events.

The Calamocha fault is an 18-km-long, NNW–SSE striking pure normal fault that moves down the northern sector of the Jiloca graben with respect to the Neogene infill of the Calatayud basin (central Iberian Chain). Its structure and kinematics are characterized by means of detailed geological mapping, morphotectonic analysis and data recording at the outcrop scale. The Calamocha fault represents the inversion of a previous contractional fault zone under the recent tensional stress field (WSW–ENE trending σ 3 trajectories). The extensional activity started during the Late Pliocene (ca. 3.8 Ma), accumulating a maximum net slip of 190–230 m (long-term slip rate of 0.05–0.06 mm/a). The palaeoseismological study of three artificial exposures near Calamocha town evidenced recurrent slip during the Late Pleistocene, which proves its active character. Analysis of faulted clastic alluvial units, dated by means of optically stimulated luminescence (OSL), reveals at least eight slip events since 145.9 ± 9.1 ka, the last one being younger than 13.8 ± 0.9 ka. Only a few events represent visible accumulated displacement on the main synthetic rupture surfaces; this allows a rough estimate of the short-term slip rate (during the Late Pleistocene) of about 0.1 mm/a, faster than the long-term rate. The Calamocha fault could potentially produce a characteristic earthquake (in the sense of Schwartz and Coppersmith, J Geophys Res 89:5681–5698, 1984) with moment magnitude M w ≈ 6.7 ± 0.3 ( M w ≈ 6.9 ± 0.3 in a scenario of activation of the whole Calamocha–Daroca fault zone), average coseismic displacement of 0.5–1.3 m and average recurrence period under 15 ka.

The Lijiang–Jinpingshan fault (LJF) is an important secondary boundary fault that obliquely cuts the Sichuan–Yunnan rhombic block. It is of great significance for understanding the tectonic evolution of the Sichuan–Yunnan rhombic block and even the southeastern margin of the Tibet Plateau. Based on a digital elevation model (DEM), this work combines ArcGIS with MATLAB script programs to extract geomorphic indices including slope, the relief degree of the land surface (RDLS), hypsometric integral (HI), and channel steepness index (ksn) of 593 sub–watersheds and strip terrain profiles around the LJF. By analyzing the spatial distribution characteristics of the geomorphic indices and combining the regional lithology and precipitation conditions, the spatial distribution of the geomorphic indices around the study area was analyzed to reveal the implications of the LJF’s activity. The results of this work indicate that (1) the distribution of geomorphic indices around the LJF may not be controlled by climate and lithological conditions, and the LJF is the dominant factor controlling the geomorphic evolution of the region. (2) The spatial distribution patterns of geomorphic indices and strip terrain profiles reveal that the vertical movement of the LJF resulted in a pronounced uplift on its northwest side, with tectonic activity gradually diminishing from northeast to southwest. Furthermore, based on the spatial distribution characteristics of these geomorphic indices, the activity intensity of the LJF can be categorized into four distinct segments: Jianchuan–Lijiang, Lijiang–Ninglang, Ninglang–Muli, and Muli–Shimian. (3) The activity of the LJF obtained from tectonic geomorphology is consistent with the conclusions obtained in previous geological and geodesic studies. This work provides evidence of the activity and segmentation of the LJF in tectonic geomorphology. The results provide insight for the discussion of tectonic deformation and earthquake disaster mechanisms in the southeastern margin of the Tibet Plateau.

Clarifying the response relationship between soil radon gas anomalies and active fault tectonic geomorphology, and to explore a rapid prediction method for concealed fractures, soil radon gas measurements and unmanned aerial vehicle micro-geomorphic scanning were carried out in the basin section of the Aba South Fault in western Sichuan. The areas of radon gas anomalies and tectonic features formed by fracture activities are highly consistent with the distribution areas of hidden fractures. It is concluded that the combination of soil radon gas measurements and tectonic geomorphologic analysis can rapidly and accurately predict hidden fractures covered by Quaternary sediments.

The present study aims at deciphering the morphometric neotectonic features in the badland affected part of the Mandakini River watershed of Chitrakoot, India. The study attempts to decipher the relative time sequencing of the morphotectonic events based on certain assumptions. Badlands are essentially erosive systems that result due to some critical combination of multiple factors such as a change in rainfall pattern, deterioration of soil properties, overgrazing history, changes in land use and land cover, changes in groundwater conditions, etc. and may or not have additional impetus due to tectonic events in their growth. The thin layer of sediments with variable thickness showing active badlands in the study area overlies the southernmost part of the Faizabad Ridge, which has a subsurface horst formation. With the assistance of remote sensing and GIS, numerous morphotectonic parameters have been determined. The result shows that the less elongated (Re = 0.7) shape of the Mandakini River watershed, Hypsometric integral (HI = 0.48), and basin shape index (Bs = 1.6), and the windy channel are indicative of moderately active tectonism in the watershed. Although the watershed is more or less symmetrical in some parts, the basin asymmetry factor (AF) is 55.24, which again indicates there is a partial impact of low active tectonics on the watershed under the study area. Sub-watersheds at the third order-level show significant variations of these morphotectonic indicator parameters observed through the sub-watersheds of the study area. In this regard, it is also of significant consideration that the spatial orientations of several sub-watershed show strong discords from the general orientations of the rest of the sub-watersheds at the third-order level, and as such, they occur as morphometric 'inliers' in the current scheme of the current drainage processes. Continuous, uninterrupted geomorphic processes cannot account for this discord, and in the absence of any significant anthropogenic interference, these could only be correlated to aggravating impacts of neotectonics interventions. On the basis of significant values of the morphometric parameters indicative of neotectonism and spatial discord of the sub-watershed, a division of zones has been attempted here, showing a degree of neotectonic interference during the sustained erosive phase of badlands formations. The values are found to be ranging from High Tectonic to Low tectonic signatures of different tectonic activity phases. The tectonic events have been classified in the GIS environment, and the spatial signatures of tectonic events, namely the High Tectonic Activity Phase (HTAP), Moderate Tectonic Activity Phase (MTAP), and Low Tectonic Activity Phase (LTAP), have been deciphered. Finally, the present work offers assumptions for sequencing the events.