Denudation Processes Research Articles

Prospects for the allocation of Paleorousels in the subsalt complex of the south-east of the Caspian sedimentary basin

development and features of the formation of the sedimentary complex of the south of the Caspian sedimentary basin are presented. The complex geological structure of the region is mainly due to the influence of tectonic, volcanic and denudation processes on sedimentation. The introduction of terrigenous material deep into the sedimentary basin (Matken-Ushmolinsk, Biikzhal and South Embin zones) by paleorubic flows contributed to the emergence of accumulative shafts and interbranch uplifts composed mainly of clay rocks with alternating siltstone-sandstones. In the paleorusls themselves, coarser sediments were deposited – gravelites and sandstones. The reconstruction of the conditions of formation of sand bodies made it possible to predict their facies composition, morphology and identify patterns of spatial placement, and are also of great interest in the search for oil and gas deposits in deep-lying lithological traps. The prospects of these structures and their resource potential are evidenced by the world experience in identifying large deposits of hydrocarbon raw materials. This is a new highly promising direction of large accumulations of hydrocarbons for the Caspian Basin. The results of drilling deep wells conducted in recent years have made it possible to refine the internal structure, substantiate new facilities in the Late Paleozoic sedimentary complex, and reassess the prospects of oil and gas potential and forecast oil and gas resources of the south of the Caspian Basin.

Co-seismic deformation and related hazards associated with the 2022 Mw 5.6 Cianjur earthquake in West Java, Indonesia: insights from combined seismological analysis, DInSAR, and geomorphological investigations

IntroductionOn November 21, 2022, a magnitude Mw 5.6 earthquake struck Cianjur Regency in the West Java Province of Indonesia. It was followed by at least 512 aftershocks that persisted from November to June 2023. This seismic event occurred in an area previously unrecognized as an active fault zone. The consequences of this earthquake in Cianjur were severe, leading to both loss of life and extensive structural damage. The substantial damage to buildings was likely a result of abrupt alterations in the local topography due to surface deformation effects.ObjectivesThis research endeavor aims to spatially determine the patterns of ground surface deformation and its relationship with local geomorphological setting due to earthquakes in Cianjur in 2022.MethodsIn this study we conduct seismological analysis of 45 seismic stations, statistical analysis of mainshock and aftershocks data, RADAR Sentinel-1 imagery and employed the DInSAR methodology. Field survey was also conducted to determine the geomorphological characteristics in the study area.ResultsThe outcomes disclosed that the deformation encompassed both subsidence and uplift. The results signify that there was subsidence deformation in the vicinity of Cianjur and its environs during the primary earthquake on November 21, 2022, with an average deformation value of approximately -5 cm. In contrast, the measured deformation during the aftershocks exhibited uplift deformation, with an average value of 10 cm. The examination of deformation patterns amid the 2022 Cianjur earthquake sequence detects elevated deformation values in the vicinity of Cugenang district, with an orientation running from northwest to southeast. The geomorphological investigation conducted indicates that the region of Cianjur encompasses a variety of landforms, such as volcanic, structural, fluvial, and denudational. These landforms exhibit distinct responses to seismic activities. Co-seismic hazards, such as landslides frequently occur as a consequence of seismic events in mountainous terrain.Main ConclusionsSpatio-temporal variation of ground deformation could arise from various causes, such as the number and distribution of aftershocks, stress redistribution, fault interactions, secondary effects, and local geological settings. The mainshocks release accumulated stress along a fault, resulting in particular types of deformation, whereas aftershocks may redistribute stress exhibiting on adjacent faults. Secondary effects triggered by aftershocks, coupled with local geological and geomorphological conditions, further contribute to the diverse patterns of ground deformation observed during seismic events. The results of the study revealed that ground deformation had the greatest impact on fluvial, volcanic, and denudational processes, resulting in notable subsidence and uplift in specific regions. The occurrence and magnitude of co-seismic landslides were triggered by both mainshock and aftershock events, which occurred on weathered geological materials. These effects were further amplified by the simultaneous presence of the rainy season.ImplicationsThe knowledge gained from this research can be applied to evaluate the impacts of earthquakes and to proactively reduce future risks.

Quantitative and qualitative study of the Tawi basin: Inferences from Digital Elevation Model (DEM) using geospatial technology

The quantitative and qualitative analysis of the basin is fundamental to understand the structural and hydrological control of the basin. In the present study morphometric and morph tectonic parameters of the Tawi basin has been analyzed to infer the geological variation, topographic information, structural and complex tectonic behavior at a watershed scale. The assessment of several of drainage network and their relative parameters has been quantified by using the Digital Elevation Model (DEM) based analysis in the Geographic Information System (GIS) environment. Based on the quantitative analysis in terms of linear, aerial and relief it is well understood that the basin is inhomogeneous in nature, less structurally stable, very gentle to steep slopes, compounded by aggradational and denudational processes in large scale, exhibited by incompetent rocks and a portion of the basin is prone to flood particularly in the lower reaches. The quantified results show that in the various watersheds of the Tawi basin bifurcation ratio (Rb) varies from 0.001 to 6.80 and the mean bifurcation ratio (Rbm) varies from 2.58 to 4.11. The mean stream length (Lsm) in the various watersheds of Tawi basin varies from 0.019 to 60.26 km. The drainage density (Dd) of Tawi basin varies from 0 to 9.63 km/km2, and the value of the drainage texture (Td) varies from 3.76 to 13.38 km-1. The qualitative analysis based on the asymmetric factor (AF) of the Tawi basin shows that the watersheds W5 and W6 are moderately asymmetric, and W2 and W4 as strongly asymmetric in nature, whereas the hypsometric integral (HI) values reveal that watershed W1 is the most stable watershed with a highest HI value of 0.89, while the W7 is the least stable with a HI value of 0.28, providing a comprehensive understanding of the geomorphic dynamics in the Tawi basin.

Fluvial Morphology in Different Permafrost Environments—A Review

This review presents a synthesis of the interaction between the hydro-morphological processes on interfluves and channels within fluvial catchments in permafrost regions. Both in modern and ancient permafrost catchments, this integrated landscape is quite diverse because of a variegated extent of frozen ground, density of vegetation cover, snow thickness, and other local factors. Moreover, temporal changes in environmental conditions are expressed in the morphological evolution of catchments. Channel patterns vary between single- and different multi-channel forms while the interfluves show a high diversity ranging from complete stability to intense denudation by surface runoff. It appears that braided channels, despite their high energy, were only significant during short intervals of peak discharge and transported only limited amounts of eroded sediment, while other channel patterns required more subdued annual discharge variability. Further, denudational processes on interfluves were a specific characteristic of landscape evolution during subsequent ice ages, especially in conditions of snow-rich and poorly vegetated, seasonal frost, or discontinuous permafrost resulting in the formation of extended planforms (cryopediments). In contrast, interfluves appeared to be rather stable on continuously frozen soils.

БЛОКОВИЙ ХАРАКТЕР НОВІТНЬОЇ ТЕКТОНІКИ СЕРЕДНЬОГО ПРИДНІПРОВ'Я НА ОСНОВІ КАРТ РІЗНИЦЬ БАЗИСНИХ ПОВЕРХОНЬ

Background. The tectonic evolution of the Middle Dnipro region in modern times is particularly complex. The presented studies were conducted within the right-bank part of the Middle Dnipro, since the maximum activation of neotectonic activity zones is observed in this region, with significant gradients of the latest tectonic movements and their impact on the formation of the modern relief, that require a comprehensive assessment of the impact of geological and geomorphological factors on their formation. Methods. Structural and morphometric studies within the Middle Dnipro region, using remote sensing methods and spatial-analytical modeling, allowed us to determine morphometric parameters related to the terraced levels of the Dnipro River, the processes of deep erosion, denudation and accumulation, as well as the nature of recent and modern tectonic movements. Results. Detailed interpretation of multi-genetic and multi-order structural and morphometric maps, as well as in-depth geological analysis, allowed us to identify morphostructures and block structures of the crystalline basement (regional blocks and local microblocks), which are distinguished by differentiated tectonic movements and peculiarities of tectonic development. Сonclusions. The neotectonic conditions of formation and development of the paleorelief of the Right Bank of the Middle Dnieper are reconstructed. The peculiarities of the development of terraced levels in the Neogene and Quaternary periods are established. The obtained data can serve as a basis for analyzing the influence of tectonic movements on the activation of hazardous geological processes within the Middle Dnieper region and forecasting their development in the future.

The origin, conditions and mechanism for the formation of alpine-type hyperbasites of the Lesser Caucasus

The problem of hyperbasites origin is one of the widely discussed topics in geology. This is because they often appear when no expected. Their development does not correspond to the general regularities of the geological complexes’ development. Therefore, when problematic instances of hyperbasites appear, discussion is inevitable. This is due to the imperfections of existing concepts, which are not without flaws. The essence of this concept lies in the fact that during the rotation of the Earth around its axis, geodynamic forces are formed. The hyperbasites complex by its nature belongs to deep igneous formations formed at the initial stage of development of volcano-plutonic processes, where the composition of magmatic products was not subject to decomposition. In general, the origin of igneous rocks is associated with deep anomalous processes, which were formed under the influence of geodynamic forces, where decompression of mantle matter occurs, causing a catastrophic increase in the volume of mantle matter, as well as the associated development of volcanoplutonic processes. Hyperbasites are formed both in divergent and convergent zones of the Earth’s crust. The main factor for their formation is high pressure – deep thermodynamic conditions, where there are no favorable thermodynamic conditions for the complete separation of magmatic melts by composition. The emergence of hypermafic rocks on the surface is associated with geotectonic or denudation processes. Denudation processes can expose only those hypermafic formations that are located at the site of formation. These zones include ancient platforms, sheets, terranes, etc., which were cut by deep erosion processes. As for those hyperbasic formations that are classified as alpinotype hyperbasites, they were moved to the structure of the Alps-Himalayan folded zone from the basement with a collision with subsequent geotectonic processes, where they formed in the bed of the Paleotethys Ocean, both in the process of divergence and convergence. The noted pattern of formation and the mechanism of formation of alpine-type hyperbasites clearly corresponds to the patterns of development of geodynamic forces in the face of the Earth, also with natural laws, which are the main factors in the evolution of the Earth’s crust. From the standpoint of KDEZK, the origin, mechanism of formation, as well as the form of distribution of alpinotype hypermafic rocks of the Lesser Caucasus occurred in the Paleotethys bed, under different thermodynamic conditions and at depths. Further, as a result of the collision, it participated in the formation of folded zones of the Lesser Caucasus. Within the Lesser Caucasus, two genetic types of hypermafic rocks are exposed. Some of them correspond to the convergent zone of the Tethys paleocean, while others correspond to divergent zones. In terms of ore content, the most promising are those hypermafic rocks that are genetically related to convergent zones.

Geoheritage and Cultural-Religious Heritage of Samalute-Minia Area in North Egypt

Geodiversity, geoheritage, geoconservation, and geotourism insights are meticulously interrelated. Their investigations are of comprehensive attention worldwide because of their high scientific, educational, scenic, and recreational values. Various new destinations in Egypt have been promoted for the geotourism and abundance in significance geological heritages in which Samalute-Minia Area is one of the most energetic tourist’s magnetism. The study area is an imperative geo-cultural province that has significant number of geosites and geotouristic fascinations, demonstrating broad array of distinctive phenomena. The latter are assigned to remarkable geomorphological, volcanological, hydrogeological, quarrying, historical, and cultural landscapes that are deliberated a vital part of the polythematic geopark. All of these sites allow the visitors, sightseers, and indigenous populations to enjoy different aspects of tourism such as religious, antiquities, recreational, safari, or ecological tourism as the root for providing the commitment, education, and pleasure. The goal of the present paper aims to stress the reputation of the geological heritage earmarked by Samalute-Minia Area. A quantitative assessment of geodiversity at the study area was carried out using the Brilha’s method (2016) in which the evaluation outputs are labeled for geotourism obligations. A list of eight geosites has been inventoried. Among the principal geosites are (1) geomorphology and karst landforms (GKL), (2) circular structural landforms (CSL), (3) volcanic landforms (VL), (4) riverine landforms (RL), (5) Christian Religion sites (CRS), (6) ancient Egypt monuments (AEM), (7) industrial sites (IS), and (8) hydrogeological aquifers (HA). Quantitative valuation has been revealed that the bunched geosites of GKL, VL, and RL have great scientific and educational value scores, while the geosites of CRS and AEM have high potential touristic use compared to low value for the IS. Regarding the risk evaluation, a high degradation risk is assigned to the sites of AEM, RL, and HA. Severe threats comprising pollution, rapid urbanization, intense degradation of underground water, illegal water pumping, quarrying/excavation, bumpy tourism, and lacking of environmental management are the chief causes for the degradation risk. The lasting five geosites display a moderate to low risk of degradation because there are no extreme observed denudation processes that generate degradation. The protection and geoconservation, increasing the touristic attractiveness, and the socio-economic development for the local community could be proposed in order to decrease the high degradation risk for some geosites. Lastly, the Samalute-Minia Area needs more scientific and potential geoheritage study, improvement in the security circumstances, promotion of the geosites, and strategic implementations as well as regulation constraints for continuous regional development to improve geotourism and geoconservation. The geotourism development would diminish the rate of joblessness and immigration, offer scenarios for dropping poverty through engaging the local inhabitants in tourism activities, and ensure the protection and educational stopovers to well-known geosites.

A MODEL OF THE LATE MESOZOIC AND CENOZOIC THERMOTECTONIC EVOLUTION OF THE PRE-MESOZOIC BASEMENT ROCKS IN SOUTH TUVA

Thermotectonic modeling was performed for the crystalline rocks of South Tuva using the apatite fission-track analysis. Thermotectonic modeling made it possible to visualize the Late Mesozoic and Cenozoic cooling history of the Pre-Mesozoic basement rocks, and to reconstruct the chronology and scale of the denudational processes over the last 125 myr and the evolution of paleorelief of South Tuva over the last 100 myr. The modeling results depicted several Mesozoic-Cenozoic episodes of cooling due to differential denudation and exhumation of the Pre-Mesozoic basement rocks. A differential denudation is related to an asynchronous activation of fault structures controlling the tectonic evolution of South Tuva. It is shown that the Early Cretaceous (~125–100 Ma) activation of the Agar-Dag-Oka thrust fault zone could result from the post-collisional processes after the collision between Siberia and Amuria and/or consecutive collision between the Cimmerian blocks. An intense activation of the Agar-Dag-Oka fault zone in the Late Cretaceous (~100–75 Ma), accompanied by significant basement rock exhumation in the eastern South Tuva to absolute heights of 1200 m, could be caused by the Karakoram-Pamir collision in the south of Eurasia. The Late Cenozoic (25–0 Ma) activation of the main fault zones of South Tuva represents a far-field effect of the Indo-European collision on the southern Eurasian continent. At the same time, there were the maximum basement uplift in the junction zone between the South Tannuola and Ubsunur-Bii-Khem fault zones and the transformation of relief of South Tuva from moderately dissected, with absolute heights of 500 to 1400 m, to modern, with absolute heights of 800 to 2600 m.

Evaluation of Microbiological and Chemical Properties of Soils as a Result of Anthropogenic Denudation

Excessive agricultural intensification adversely affects soil quality, particularly in hilly terrain, leading to increased erosion. Anthropogenic denudation, intensified by tillage erosion, results in the displacement of soil material from hilltops and shoulders to their bases. The research hypothesis posits that tillage erosion adversely affects the microbiological and chemical properties of soils, especially at the hilltops of intensively cultivated areas. The study aimed to assess the microbiological and chemical properties of Luvisols cultivated under conventional plowing in the moraine region of the Southern Krajna Lakeland, Poland. The evaluation focused on the results of soil sample analyses taken from the hilltops and foothills of eroded mounds. Microbiological investigations included determining the abundance of actinomycetes, filamentous fungi, heterotrophic bacteria, cellulolytic microorganisms, copiotrophs, and oligotrophs. Additionally, pH values and the contents of phosphorus, potassium, magnesium, total organic carbon, and nitrogen were determined. A higher abundance of bacteria, actinomycetes, and copiotrophs was observed at the foothills. Statistically significant differences due to slope effects were noted for all chemical parameters, with higher concentrations of organic carbon, nitrogen, potassium, and phosphorus found in the foothill areas. Understanding denudation processes can contribute to sustainable soil resource use and agrocenosis conservation.

Late Cretaceous erosion and chemical weathering record in the offshore Cape Basin: Source-to-sink system from Hf[sbnd]Nd isotopes and clay mineralogy

Source-to-sink research has often used sediment fluxes as a fundamental parameter when seeking to understand the perturbations caused by tectonics or climate. This parameter is often interpreted only in terms of erosion rates, dismissing the component exerted by chemical weathering. In this study, we characterize sediments from the Deep Surface Drilling Program core 361 (DSDP 361) located in the Cape basin to show the evolution of both, physical erosion and silicate chemical weathering, during the late Cretaceous (100.5–66 Ma) in the source-to-sink system consisting of the South African plateau and the Cape Basin. Transmission Electron Microscopy (TEM) images and trace element analyses indicate that detrital clays predominate within the site and thus reflect variations in surface continental processes. Clay mineralogy shows a predominance of detrital smectite (60–98%) throughout the section. However, an increase in primary clay minerals, in particular illite (20%), indicates a relative enhancement in physical erosion, while an increase in palygorskite (10%) indicates regional climate aridification during the Campanian–Danian interval (ca. 77–62 Ma). Concomitant to this enhancement, we observe both, more radiogenic Hf isotopic compositions and less radiogenic Nd isotopic compositions in the clay fractions (< 2 μm). These variations can be respectively associated to an increase in silicate chemical weathering and the incorporation of unradiogenic material, likely related to the orogenic belts present on the western-south margin of Southern Africa. The regional aridification and the global climate cooling trend observed on δ18O benthic foraminifera records do not appear as suitable mechanisms for the increase in physical erosion and silicate chemical weathering observed. Our results, together with the reported increase in sedimentation rates and the reported tectonic uplift between 80 and 70 Ma, suggest that it is tectonic activity and not climate the main driver in the enhancement of denudation processes. Furthermore, our data suggests that such uplift episode could have impacted the regional climate by causing a rain-shadow effect, with an inland aridification suggested by the increase in palygorskite proportions. The increase in silicate chemical weathering suggested by our new dataset begins in the Campanian (ca. 77 Ma), later than the onset of the global climatic cooling trend that occurs from the Turonian onward. If enhanced weathering of the South African Plateau may not have triggered the recorded climatic cooling, it may still have contributed to maintain cooler conditions in the Campanian-Danian interval.

Ecological successions of phytocenoses in the process of formation of the phytomeliorative cover of landfills

The vegetation in the landfills within the Western Forest Steppe of Ukraine is characterized by the rich species composition of the grass cover near the bottom and its almost absence at the top (southern slope). The transforming function of adapted plant groups leads to significant reduce of the intensity of denudation processes of technogenic substrates, and initiate soil-forming processes in them. The aim of the work is to establish the peculiarities of successional processes in different types of landfills of the Western Forest Steppe of Ukraine, depending on various technogenic factors. It was found that large landfills have the largest species composition – Lviv – 30 species, Ternopil – 20, Lutsk – 19. Small landfills – Lavrykiv – 10 species, Vereshchytsya – 11 species have the smallest species composition. Succession stages (syngenetic, initial endo-ecogenetic, mature endo-ecogenetic) are described at each investigated landfill, and projective coverage is calculated. It was established that the highest coefficients of Jaccard’s floristic similarity are characteristic to the investigated areas of landfills where there is no waste dumping, or it is only in certain areas (the second phase of dumping). The average coefficient of floristic similarity of all investigated landfills is K j =0.29.

Late Quaternary evolution of the Belan River Basin, Central India

The Marginal Gangetic Plain is the southernmost segment of the Ganga Plain, formed by Himalayan Orogen thrust fold stress flexing the Indian lithosphere. Rivers originating in the Himalayas have received much attention (i.e., Ganga, Yamuna, Kosi, Ghagra, etc.). In contrast, the tributaries draining from the peripheral bulge of the foreland basin have not been studied in detail, although it bears signatures of seismic activity in the basement of the craton. The Belan River, a tributary of the Tons River and sub-tributary of the Ganga River, drains through the Marginal Gangetic Plain. Various tectonic-induced geomorphic signatures have been identified using Landsat Images, such as fluvial incision, river shifting, gorges channel formation, etc., in the Belan River Basin. Geomorphic indices of active tectonics (asymmetry factor, SL index, basin elongation ratio, and long profile), drainage pattern, and lineament study have been performed for the Belan River Basin. These parameters indicate slope adjustment due to the uplift and subsidence of the parts of the basin area. The most recent and extensive valley fills started accumulating at ∼51 ± 7 ka and persisted until around ∼22 ± 2 ka. The aggradation was accompanied by a weakening summer monsoon, followed by incision after 22 ± 2 ka, indicating a return to warmer and wetter conditions and a stronger summer monsoon after the Last Glacial Maximum (LGM). Tectonic exhumation in the southern and south-eastern parts of the Belan River Basin revealed by geomorphic indices. These findings indicate that the drainage networks of the Belan River Basin were built over a tectonically controlled valley and that denudational processes have been transforming the basin for a considerable period.

Assessing the potential of syn-rift sediments for geochronological dating and its implications for the development of Makanjira-Shire basin in south Malawi Rift

The Upper Shire River basin, located within the zone of progressive interaction and linkage between the southern Malawi Rift and Shire Rift Zone, East Africa, presents an early-stage rift setting where rapid denudation processes take place and have profound influence on the geomorphological evolution of the region. The basin is key to the understanding of mechanisms involved in propagation and growthin young rifts. Although the tectonics in the region are well studied, lack of age constraints due to well-dated strata poses challenges in the understanding of the timing and mechanisms of rift evolution in this section of the south Malawi Rift.We used syn-rift sediments deposited from the rift shoulders to test the applicability of OSL and radiocarbon dating techniques in a poorly dated data-constrained region of the Malawi Rift.Our results suggest that proper sampling strategy is paramount in using the OSL technique for dating in areas of high dosage such as the one under consideration. However, the technique offers potential for use in these areas. Furthermore, we conclude from these findings that the evolution of the Upper Shire basin was triggered by tectonic movements along the Makongwa scrap that were responsible for redirecting the Likwenu River into the in the Zomba Graben through the Upper Shire at least during the Upper Pleistocene.

MORPHOLOGY AND GENESIS OF UNDERWATER BARS AND RIDGES OF THE EAST SIBERIAN SEA&lt;a href="#FN4"&gt;&lt;sup&gt;4&lt;/sup&gt;&lt;/a&gt;

Shelf zone of the East-Siberian Sea is one of the least studied marine areas of the Russian Arctic. One of the important unsolved problems is the existence of a ice sheet in the area of the New Siberian Islands, and the debate about the age and genesis of underwater ridges (bars). Based on geological and geophysical field work condicted by VSEGEI in 2018 and 2020, laboratory research, and data analyses, two types of submarine ridges, principally different in morphology, sediment composition, age, and genesis were identified. Ridges located within the submarine plain on the outer periphery of the submerged valley of the Pra-Kolyma river and around the New Sibir’ Island are asymmetric, have a relative height of 1–2 m to 4–6 m, an average width of 2–4 km (up to a few tens of km) and an average length of 25– 30 km (up to 100 km). According to the sampling data, the ridges of this type are composed of very dense clayey-silt without inclusion of coarse clastic material. The age of the deposits forming the ridges is Late Pleistocene (18–13 ka BP). Formations of the Upper Pleistocene age are exposed in the inter-ridge hollows. The composition, morphology, and age of the ridge deposits suggest that their genesis is associated with denudation processes, but the mechanism of their formation is not obvious. The second type of ridges includes a system of coastal bars located at a distance of up to 30 km from the coast of New Sibir’ Island and composed of fine-grained, well-sorted sands. The width of the ridges varies from 1 to 2 km, the height is from 4 to 8 m, and the length is 10–15 km. The ramparts have a slightly asymmetric shape, with a gentler slope from the side of the island. This system of ridges was formed as a result of accumulative processes in the Holocene. The obtained data do not support the hypothesis of the extension of the Late Pleistocene ice sheet to the shelf.

Granite Weathering, Denudation Processes, and Associated Landforms in the Itu-Cabreúva Region, São Paulo, Brazil

The Itu-Cabreúva region is located about 90 km northwest of the São Paulo city center. The geological setting is characterized by the expressive occurrence of Neoproterozoic granitic rocks. These intrusive rocks form large plutons that have given rise to flattened hills, valleys with concave-convex slopes, and superficial drainage systems. As part of this larger framework, several smaller landforms with unique appearances occur, which can be categorized into six groups: nubbin, boulder, balanced rock, castle koppie, cave, and minor form. Although these reliefs were formed under similar weathering conditions, the research results show that the physical properties of the lithology and the nature and density of the joints strongly influenced the shape and size of the blocks. These geoforms have exceptional scenic value and are situated in a geographically advantageous location for a range of educational and recreational activities that can be adapted to different levels of knowledge. The implementation of such proposals in the context of understanding the physical environment would result in a number of benefits, including (i) greater community involvement in the environment, (ii) valorization of the local landscape as a historical record of the planet's evolution, and (iii) improvement of urban geological risk prevention programs. Finally, these landforms are fascinating and offer conclusive evidence that can be observed on a wide range of scales, illustrating how the brittle deformation and magmatic fabric of the granite massifs influenced the development of the local landscape.

Drainage network rearrangement during the formation and segmentation of a Paleogene intraplate half-graben: Insights from fluvial captures records and longitudinal profiles

Rivers play an important role in modifying landscapes through denudation processes, which can be influenced by changes in tectonics, climate and eustasy, causing erosive pulses and river capture events that alter the geometry and topology of the drainage network. Therefore, drainage networks are not static features over time and are modified and rearranged by shifts in their boundary conditions until a state of dynamic equilibrium is reached in the landscape. The region of the Paraíba do Sul Middle Valley (PSMV), in Southeastern Brazil, has important records of captures and recent drainage rearrangements, which show a state of transition in the landscape and, consequently, the reorganization of drainage networks. This region is in the central segment of the Continental Rift of Southeastern Brazil (CRSB), a prominent tectonic feature that can be described as an intraplate half-graben. While fluvial profiles and fluvial gradient indices are valuable tools for studying the landscape evolution, their application to investigate the erosive power of rivers and how the topography of a half-graben affects the rearrangement of the drainage network over geological time is still limited. Specifically, there is a need to explore how the topography of the active border of a half-graben differs from that of the flexural border in terms of river network organization and fluvial erosion patterns. This study aims to characterize the different stages of rearrangements of the drainage network and their relation with the events of formation and segmentation of a half-graben. A total of 21 basins were analyzed in both Fault and Flexural Border sectors, extracting geomorphic parameters, such as slope, drainage area, concavity, χ and ksn. A more specific study was carried out in areas where river captures were recognized as been related to the half-graben formation and segmentation events. The ksn calculated for the main rivers demonstrates that the formation of the rift and its consequent configuration in half-graben granted a greater erosive power for the basins that drained the active fault of the rift, represented by the basins of the Fault Border Sector of the study area. The tectonic events registers in the fluvial system were analyzed using the χ method and the main migration tendency of the dividers was extracted from the difference in the values of this parameter in areas close to the interfluves. With this, it becomes evident that the geometric configuration imposed in the half-graben establishes, from the beginning of the rift phase, an important control on the erosion potential of the rivers located in the active and flexural borders. This control resulted in ancient river captures, currently exposed as inflections in the main river channels towards the local depocenters, thus demonstrating that this type of tectonic event can generate disturbances in the river system that can be observed even today, tens of millions of years after it happened.

The Keivy Domain of the Kola Granulite–Gneiss Area on the Baltic Shield: Most Ancient Median Massif of the Continental Crust

Studies of lithotectonic formations within the Keivy domain of the NE Baltic Shield have shown that the domain was tectonically overlapped by adjacent microcontinents during regional collision processes in the Late Archean. As a consequence, the continental crust of the Keivy domain was submerged, relative to other blocks of the continental crust, and the described domain acquired the features of a classical median massif. Surrounded on all sides by collision systems, the Keivy median massif entered the cratonization regime. This led to intensive processes of denudation of the surrounding domains of the crust and the accumulation of a thick sedimentary cover on the surface. The described processes occurred during the formation of the first supercontinent (Monogea) in the history of the Earth and the manifestation of the Early Precambrian Huronian glaciation, which left its traces on most domains of the Earth’s continental crust. Thus, the processes of peneplain formation within the Keivy massif occurred under the cold weather conditions, high volcanic activity in the peripheral zones, and sedimentary cover saturation with the products of the physical and chemical mineral transformation of tonalite–trondhjemite and greenstone rock assemblages. The unique combination of certain geodynamic and climatic cycles on the Baltic Shield in the Late Archean led to the accumulation of extensive stratiform deposits of alumina raw materials within the Keivy median massif.

On the Mechanisms of Generation of Excessive Horizontal Compression in the Continental Crust

It is proposed to consider the processes of surface denudation and crustal magmatism to explain the formation of increased horizontal compressive stresses in the crust, which are excessive relative to the lithostatic pressure. Exhumation of a rock results in only partial unloading of the crust due to the removal of the weight of the overburden, unless the crust is above the yield point. This is due to the fact that in the case of exhumation, the unloading follows the elastic law. As a result, residual stresses of horizontal compression received at the stage of cataclastic flow arise in the rock. Another mechanism of formation of additional compressive stresses in the crust is related to volcanic and magmatic processes. The ascent of a magma along subvertical faults and fracture networks is only possible under the conditions when the magma pressure at the propagation front exceeds the level of horizontal compression in the rock. As a result, below the magma propagation front, the level of horizontal compressive stresses in the rocks rises to the level of magma pressure. Since the pressure in the subcrustal or intracrustal magma chamber is close to the lithostatic pressure of the overburden, above the magma propagation front in the fault, the stresses normal to the fault exceed the level of vertical compression. Thus, crustal magmatization is capable of changing the crustal stress state from horizontal extension to horizontal compression.

Effects of geomorphological processes and phytoclimate conditions change on forest vegetation in the Pomeranian Bay coastal zone (Wolin National Park, West Pomerania)

The functioning of plant associations, including forest associations, in the coastal cliff edge zone of the Pomeranian Bay in the Wolin National Park (WNP) is determined by short-term factors related to the dynamics of erosion and denudation processes and long-term phytoclimatic conditions’ changes. The study presents a temporary analysis of the occurrence of sea abrasion and water and aeolian erosion, based on the applied hydrometeorological threshold values. The influence of changes in phytoclimatic conditions on the development and productivity of coastal forests with the dominant species of Fagus sylvatica was also presented. Assessments of spatial susceptibility to erosion of the cliff coast and the existing plant associations were also carried out in conditions of the risk of coast erosion. It was found that 55% of the cliff edge zone of the Pomeranian Bay of the WNP and the forest associations (mainly Luzulo pilosae-Fagetum) occurring there are in the zone of particular risk of increased erosion and denudation processes. In addition, unfavourable trends in changes in phytoclimatic conditions in the 21st century were found, which reflect climate changes unfavourable to the development of beech forests on Wolin Island.

Denudation of the Golan Heights basaltic terrain using in-situ 36Cl and OSL dating

While erosion rates of carbonates along the Dead Sea fault (DSF) and its margins have been determined in several studies, information about denudation of basalts along the DSF are absent. Here we report concentrations of in situ cosmogenic 36Cl in bedrock and sediment samples combined with OSL ages of terraces from the Meshushim basin, a typical basaltic basin in the Golan Heights, northern Dead Sea Rift (DSR).Denudation rates of exposed and soil-covered bedrock basalts, range from 12.3 ± 1.4 mm/ka to 176.1 ± 47.4 mm/ka, well within the range of DSR values, regardless of lithology and climate. In all locations where exposed and soil-covered bedrock were samples next to each other, the soil-covered basalt erodes faster. This is regardless of notable variations in average annual temperature and precipitation. This means that bedrock outcrops were not covered and exposed very frequently, and that chemical weathering at the bedrock-soil interface is a significant erosional factor.Sediments in the Meshushim basin are stored in soil pockets and blankets on the upper plateau, colluvial material on slopes, and alluvial terraces. The difference in 36Cl concentrations between soil-covered and exposed bedrock indicates coverage duration of ca. 3–6 ka. The residence time estimate of only several thousands of years for sediments stored in alluvial terraces is 170 ± 20 y to 4000 ± 290 y. Nowhere in the Meshushim drainage system did we find evidence for storage of sediment longer than a few thousands of years.36Cl concentrations in colluvial and alluvial sediments are similar to those measured in soil-covered basalts. This similarity suggests that sub-surface weathering of basalts is the major source for sediments in upper and central segments of the basin, concurrent with the higher denudation rates of buried bedrock. However, very low 36Cl concentrations measured in samples collected in the lower parts of the basin indicate involvement of landslides which instantaneously expose previously shielded sediments that were incorporated into the drainage system. The effect of landslides is also manifested by the high basin scale denudation rates calculated from alluvial samples in various locations, as well as the geomorphological profile of the Meshushim basin. Sediment yield calculated from 36Cl concentrations measured in this study suggest temporal changes in denudation rates over the Holocene and up to the last ∼60 ka, with higher past denudation rates and sediment yield even in most of the Holocene related to present rates and yields.Overall, the results of this study show that the fact that the Golan lithology is basaltic does not result in different denudation process and rate from other locations investigated along the Dead Sea Rift, which are mostly of carbonate lithology and that relief and climate are stronger parameters than lithology in controlling denudation.