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The vicinity of the Rozprza archaeological site (central Poland) has been the area of a series of palaeoecological studies tracking the environmental history of the Luciąża River valley up to ca. 13,200 cal. BP. Numerous subfossil palaeomeanders of different sizes have been discovered in the valley floor. Here, we present the first results of multiproxy research on the paleo-oxbow lake fill, one of the oldest in the region. The wide range of palaeoecological analyses resulted in reconstructions of vegetation history, climatic, hydrological and habitat changes. The studied oxbow was an aquatic ecosystem with diverse invertebrate fauna until the end of Younger Dryas when it transformed into a limno-telmatic habitat. The sediment composition indicates active denudation processes and several episodes of turbulent hydrological conditions. Such an increased river activity could have caused flooding, resulting in an allochthonous matter supply to the oxbow lake in Late Vistulian. Environmental changes were strictly related to the regional features of the catchment, the transformation of soils, and the hydrogeological conditions. The chironomid- and pollen-inferred climatic reconstructions indicate periods of high and low continentality. The chironomid record indicates relatively cool summer conditions in the Allerød, especially ca. 13,000 cal. BP, possibly related to the Gerzensee Oscillation. On the other hand, a distinct increase of summer temperatures in Younger Dryas (up to 16 °C) was recorded. Such a situation was also confirmed in some other studies from the region, suggesting that it might be the effect of some specific, local palaeoclimatic conditions. Fundator badań: Fundator badań: Optional.empty

Post-mineralization thermal evolution is an indispensable part for geology of ore deposits. However, as two important gold mineralization regions in eastern China, the thermal histories after ore formation of the Jiaodong area is debated while that of the Liaodong area is scarce. Given that the two areas are not only in similar tectonic settings but also have gold deposits forming in the thinning and destruction of the North China Craton, therefore a comparative study can be made. Here new zircon and apatite (U–Th)/He and apatite fission track ages are presented to reconstruct the post-mineralization geological evolution. Four periods of rapid uplift and denudation happening during the 110–100 Ma, 80–70 Ma, 42–38 Ma and 35–32 Ma are defined in Liaodong, and two such periods happening during the 100–95 Ma and 80–72 Ma in Jiaodong. The small timing difference of the rapid uplift (110–100 Ma versus 100–95 Ma) can be explained by the elevation difference of the respective samples. Hence, the evolution processes between the Jiaodong and Liaodong areas are very similar during the Cretaceous, but show marked differences during the Cenozoic. After ore-forming, the erosion amount in Liaodong and Jiaodong is estimated at ∼4.8 and ∼4.7 km, respectively. Moreover, the denudation intensity in Liaodong tends to increase from southeast to northwest. The westward convergence of the Pacific Plate and associated multi-stage activity of the Tanlu and Yalujiang faults are inferred to have induced the regional-scale rapid uplift of the Jiao-Liao areas.

Accurate interpretation of clutter seismic reflection is of great significance to make clear the structural geometry and kinematics characteristics. Based on field investigations, boreholes and seismic data, forward modeling is carried out under the trishear model of fault-propagated fold principle, and the activity characteristics of the main faults in the study area are quantitatively analyzed using the balanced restoration technique, which may provide important indication for the potential petroleum exploration and development. The results show that separated by Tuziluoke and Tugerming fault, the structural style of the study area can be divided into the deeply buried forelimb, the kink band and the tiny anticline backlimb section. The Tuziluoke fault has been active with strong intensity since the sedimentary period of the Kuqa Formation and, which controls the formation of the growth strata in the deep buried forelimb of the Tuziluoke anticline. The Tugerming fault has been active intermittently since the end of the Jurassic, causing the strata denudation of the Late Jurassic to Paleogene in varying degrees and the development of series of regulating faults. The multi-stage tectonic activities caused the structural high of the anticline migrated from east to west.

Denudation rates are often estimated with high uncertainty using the average mass of material discharged through a drainage basin or considering the rate of surface processes. Estimating long-term denudation rates through these conventional methods requires the assumption that the surficial processes have remained constant throughout time. Since the earth's surface has been obliterated throughout the geological time by climate, tectonics, or the recent anthropogenic activities, the present rate of change may not represent past processes. This study presents changes in denudation rate using the 10Be (meteoric)/9Be ratio for the past 600 years from Anshupa Lake sediment record in the core monsoon zone of India. Paleodenudation rate estimated using 10Be (meteoric)/9Be varies from 392 ± 42 to 95 ± 6 t/km2/yr. Intense Indian Summer Monsoon (ISM) during the periods of solar maxima, which caused decadal-scale floods in the Indian sub-continent, favored a higher rate of denudation than the periods of solar minima, that experienced droughts in the Indian sub-continent due to weakening of ISM.

The relief and geological structure of Carpathian Biosphere Reserve represent the features of the geological and geomorphological structure of the four geomorphological regions of the Ukrainian Carpathians. The block mid-mountains of the Polonynsko-Chornohirsky Carpathians (Chornohora, Svydovets, and Uholsko-Shyrokoluzhansky massifs) and the folded mid-mountains of Marmarosy crystal massif (Marmarosy and Kuziy-Trybushansky massifs) are well protected within the reserve. The analysis of the morphostructure and morphosculpture of the reserve is carried out taking into account the longitudinal (NW–SE) and transverse divisions of the Ukrainian The analysis of the morphostructure and morphosculpture of the reserve is carried out taking into account the longitudinal (NW–SE) and transverse divisions of the Ukrainian Carpathians. The longitudinal division is associated with morphostructures of higher orders, such as second and third. The transverse division is associated with the fourth and fifth orders of morphostructures. In the analysis of morphosculpture of the reserve, the types characterized for all regions of Flysch and Crystal Carpathians are allocated. All mountain massifs and ridges could be characterized by an asymmetrical structure, such as steep northeastern slopes and acclivous southwestern slopes. The relic morphosculpture is represented by: 1) fragments of denudation surfaces of different ages such as Polonynska, Pidpolonynska, and riparian; 2) ancient glacial and extra glacial landforms; 3) areas of ancient longitudinal valleys. River valleys with a complex of different age terraces represent inherited morphosculpture. Modern morphodynamic processes are represented by height (tier) differentiation. The processes of sheet erosion, deflation, and rill erosion play an important role in the relief modeling for the tiers of strongly dissected mid-mountain relief. The lower tier of the terraced and non-terraced bottoms of the valleys are associated with the processes of leaching and erosion as well as a significant accumulation of erosion products and mudflows. Stabilized and active displacements are the most recorded among the gravitational processes and block motions. Key words: Carpathian Biosphere Reserve; Ukrainian Carpathians; relief; morphostructure; morphosculpture.

The Himalaya, a leading example of active mountains, is jointly shaped by intense tectonics, extreme climate and surface denudation. However, the causal relationship among these agents remains controversial. In this work, by an integrated analysis of bedrock channels and valley hillslopes using process-based models, we discover 3D-linear correlations in logarithmic space among precipitation-estimated stream discharge, channel gradients and valley hillslope gradients. This finding indicates that channel incision and hillslope denudation are dynamically coupled in sculpting the erosional topography in tectonically active domains of the Himalaya. The channel-hillslope coupling provides an independent approach to quantify key parameters of erosional models. Surface denudation indices simulated along streams and in drainage basins present a regular arrangement of high- and low-denudation zones across the Himalaya, which coincides well with available thermochronological and structural data and thereby supports a tectonic dominance on surface denudation rates and topography over medium-long timescale.

We used concentrations of in situ cosmogenic10Be from riverine sediment to quantify the basin‐averaged denudation rates and sediment fluxes in the Plessur Basin, Eastern Swiss Alps, which is a tributary stream to the Alpine Rhine, one of the largest streams in Europe. We complement the cosmogenic dataset with the results of morphometric analyses, geomorphic mapping, and sediment fingerprinting techniques. The results reveal that the Plessur Basin is still adjusting to the landscape perturbation caused by the glacial carving during the Last Glacial Maximum c. 20,000 years ago. This adjustment has been most efficient in the downstream part where the bedrock comprises high erodibility North Penninic flysch and Bündnerschist, whereas glacial land-forms are still prominently preserved in the upstream region, comprising low erodibility South Penninic and Austroalpine bedrock. This geomorphic observation is supported by the10Be based denudation rate and sediment provenance analysis, which indicate a much faster sediment production in the flysch and schist lithologies. Interestingly, the reach of fast denudation has experienced the highest exhumation and rock uplift rates. This suggests that lithologic and glacial conditioning have substantially contributed to the local uplift and denudation as some of the driving forces of a positive feedback system.

Evidências morfológicas e crono-estratigráficas apontam que a região do médio vale do Rio Paraíba do Sul (MVRPS) passou por dois ciclos de instabilidade morfodinâmica: o primeiro entre 10.000 e 8.000 anos atrás, e o segundo, iniciado há cerca de 250 anos (ciclo do café). Essa dinâmica evolutiva foi amplamente comprovada para a bacia do Rio Bananal, vertente direita do MVRPS. Diante disso, este estudo objetivou avaliar as repercussões desses dois ciclos na bacia do Rio Turvo, vertente esquerda do MVRPS. Foram feitos levantamentos de depósitos fluviais em diversas sub-bacias, através de mapeamento e espessura obteve-se a volumetria desses depósitos. Foram realizadas 15 análises por datação de C14 em 9 perfis estratigráficos. Os estudos geocronológicos (AMS C14) nos terraços fluviais dos rios Turvo e Pedras mostram que eles foram formados no mesmo ciclo erosivo-deposicional, entre 8000-10000 anos atrás, identificado para a bacia do Rio Bananal. Entretanto, as taxas de erosão foram superiores na bacia do Rio Bananal (sub-bacia do Rio Piracema) (38.500 m3/ano), seguido pela sub-bacia do rio Pedras (2.240 m3/ano) e demais sub-bacias do rio Turvo (320 m3/ano). Por outro lado, comparando as taxas de sedimentação do período do café, observou-se taxas semelhantes entre as bacias dos rios Turvo e Bananal (96.640 m3/ano e 97.160 m3/ano, respectivamente). Os resultados apontam um modelo de evolução geomorfológica espacialmente não uniforme, tendo a sub-bacia do Rio Pedras maior magnitude erosivo-deposicional, enquanto no restante da bacia do rio Turvo há menor estoque de sedimentos nos vales fluviais e a preservação de feições de denudação química nos interflúvios.

Landscape evolution is modulated by the regional tectonic uplift, climate change, and river dynamics. However, how to distinguish these mechanisms through the research of surface exhumation and fluvial incision remains controversial. In this study, cosmogenic 10Be, 26Al, and 21Ne concentrations in quartz from cave deposits, modern river sediments, and bedrocks were measured to constrain the applicability of cosmogenic 21Ne and discuss Quaternary landscape evolution history in the Guizhou Plateau, southeast China. Using the 26Al-10Be and 21Ne-10Be pairs to distinguish the cosmogenic 21Ne concentration from the excess 21Ne, we found that the nucleogenic 21Ne produced by the U and Th decay in quartz is significant in the samples although there is the possibility of inherited cosmogenic 21Ne. Combining with previous studies, we suggest that the precise approach for applying the cosmogenic 21Ne could be reached by (1) estimating the contribution from nucleogenic 21Ne, (2) avoiding samples with complex burial histories to exclude inherited cosmogenic 21Ne, and (3) combining the 10Be-26Al-21Ne nuclides method for the Quaternary samples. In addition, both pre-burial basin denudation rates and burial ages derived from the 26Al-10Be pair were used to determine the different timescale surface denudation rate and fluvial incision rate in relation to previous work. The consistency of the different timescales pre-burial basin denudation rate, 36Cl surface denudation rate, and modern basin denudation rate indicates that the landscape-scale surface denudation has been likely stabilized since the Quaternary in the Guizhou Plateau area. The slightly higher river incision rates than the local surface denudation rate show that the river dynamics may not have reached a steady-state due to the regional tectonic uplift in the Guizhou Plateau.

The Central Uplift in the Songliao Basin is a large consequent buried-hill structural belt between the east and west faulted zones. Some hydrocarbon-rich sags (e.g. Xujiaweizi and Changling), occur at both sides of the uplifted zone. The Central Uplift, which indicates richness in hydrocarbon resources, is a long-term hydrocarbon migration destination with favorable conditions for hydrocarbon accumulation. Drilling two risk-taking exploratory wells, LT2 and LP1, have been demonstrated by the recent breakthrough in hydrocarbon discoveries. In conformity with uplift-sag contacts and migration pathways, the researchers establish six accumulation models, namely dual consequent faults, dual antithetic faults, consequent-antithetic faults, consequent fault-consequent overlap, antithetic fault-consequent overlap, and dual consequent overlaps, and five carrier systems which include the fault-fracture network, sandy conglomerate-fault-fracture network, fault-unconformity-fracture network, sandy conglomerate-unconformity-fracture network, and sandy conglomerate-fault-fracture network-unconformity. The team divides the Central Uplift accumulation process into four stages, including fold basement denudation and leveling off, coupled weathering, and leaching in the faulted and uplifted zones, hydrocarbon accumulation with sealed overburden, and sustained hydrocarbon preservation in the Central Uplift. Based on an analogous study of hydrocarbon accumulation in the Central Uplift, they conclude that the salients between hydrocarbon-rich sags occurring in the fault subsidence period are similar in accumulation conditions to the Central Uplift. The buried hills and their internal configuration at the salients should be the focus of exploration since they are the strategic successors of hydrocarbon exploration in the Songliao Basin due to their excellent exploration potential.

The study and exploration practice of shale gas accumulation has focused on the static system comparison, key parameters analysis, reservoir characteristics, enrichment mode etc. However, the research on dynamic recovery from the original hydrocarbon generation of shale gas to the present gas reservoir is still lacking. The burial history of shale gas reservoir can reflect the overall dynamic process of early formation and later transformation of shale gas reservoir. It controls the material basis of shale gas, the quality of reservoir physical properties, preservation conditions, gas content and formation energy, which is the core and foundation of shale gas accumulation process research. Herein, based on the five typical wells data in the Northeast Yunnan, including geochronological data, measured Ro values, core description records, well temperature data, paleoenvironment, paleothermal, etc., the burial history, thermal evolution history and hydrocarbon generation history of the Lower Silurian Longmaxi Formation were systematically restored via back stripping method and EASY%Ro model. The results show that 1) the differences in the burial history of marine shale in Longmaxi Formation can be divided into syncline type and anticline type. 2) The shale gas accumulation process can be divided into four stages, namely the source-reservoir-cap sedimentation period, initial accumulation period, main accumulation period, and adjustment period. 3) Based on the characteristics of burial history and preservation conditions, the areas with wide and gentle anticline, far away from the denudation area, and buried deeply with good fault sealing ability are priority structural locations for the shale gas exploration in northeast Yunnan.

Many mountain ranges survive in a phase of erosional decay for millions of years following the cessation of tectonic activity. Landscape dynamics in these post-orogenic settings have long puzzled geologists due to the expectation that topographic relief should decline with time. Our understanding of how denudation rates, crustal dynamics, bedrock erodibility, climate, and mantle-driven processes interact to dictate the persistence of relief in the absence of ongoing tectonics is incomplete. Here we explore how lateral variations in rock type, ranging from resistant quartzites to less resistant schists and phyllites, and up to the least resistant gneisses and granitic rocks, have affected rates and patterns of denudation and topographic forms in a humid subtropical, high-relief post-orogenic landscape in Brazil where active tectonics ended hundreds of millions of years ago. We show that catchment-averaged denudation rates are negatively correlated with mean values of topographic relief, channel steepness and modern precipitation rates. Denudation instead correlates with inferred bedrock strength, with resistant rocks denuding more slowly relative to more erodible rock units, and the efficiency of fluvial erosion varies primarily due to these bedrock differences. Variations in erodibility continue to drive contrasts in rates of denudation in a tectonically inactive landscape evolving for hundreds of millions of years, suggesting that equilibrium is not a natural attractor state and that relief continues to grow through time. Over the long timescales of post-orogenic development, exposure at the surface of rock types with differential erodibility can become a dominant control on landscape dynamics by producing spatial variations in geomorphic processes and rates, promoting the survival of relief and determining spatial differences in erosional response timescales long after cessation of mountain building.

A preliminary field-based investigation was undertaken in a small (< 10 km2) river valley located in the mountainous Jura region of northwest Switzerland. The aims of the work were to assess sediment generation and annual sediment transport rates by tree throw on forested hillslopes, and to document surface hydrology characteristics on four fresh soil mounds associated with recent tree throws over a 24-day monitoring period. For the soil mounds, average sediment recovery ranged from 7.7–28.2 g (dry weight), equivalent to a suspended sediment concentration of 145.2–327.8 g L−1, and runoff coefficients ranged from 1.0%–4.2%. Based on a soil bulk density value of 1,044 kg m−3, upslope runoff generation areas were denuded by an average 0.14 mm by the end of the 24-day monitoring period, representing an erosion rate equivalent to 2.1 mm yr−1. A ca. 50 cm high soil mound could therefore feasibly persist for around 200–250 years. For tree throw work, the dimensions of 215 individual tree throws were measured and their locations mapped in 12 separate locations along the river valley representing a cumulative area equivalent to 5.3 ha (av. density, 43 per ha). Tree throws generated a total of 20.1 m3 of fine-sediment (< 2 mm diameter), or the equivalent of 3.8 × 10−4 m3 m−2. The process of tree throw was originally attributed to two extreme weather events that occurred in west and central Europe in late December 1999. Taking the 18-year period since both storms, this represents an annual sediment transport rate of 2.7 × 10−5 m3 m−1 yr−1. Exploring the relationship with wind on fall direction, 65.5% of tree throws (143) generally fell in a downslope direction irrespective of hillslope aspect on which they were located. This infers that individual storms may not have been responsible for the majority of tree throws, but instead, could be associated with root failure. Given the high density of tree throws and their relative maturity (average age 41 years), we hypothesise that once trees attain a certain age in this river valley, their physiognomy (i.e. height, mass and centre of gravity) compromises their ability to remain securely anchored. We tentatively attribute this possibility to the presence of bedrock close to the surface, and to the shallow soil profile overlaying steep hillslopes.

The increase of geomorphological research during the last decades in the Gorce Mts. caused the need for state-of-art review papers. The Gorce Mountains were formed as an isolated massif with Mt Turbacz (1310 m a.s.l.) as the highest summit. River channels are remodeled by sudden and high-level floods with the critical impact of log jams. The main processes influencing hillslope relief were landsliding, run-off, and tree uprooting. The review suggests the following issues await for studies: a long-term landscape evolution, monitoring of morphogenetic processes, and origin of landslides with their contribution to denudation rates. Also, current biomorphodynamics (uprooting process) has not been sufficiently studied.

Periglacial areas in the mountains are characterized by the highest denudation rates, which is due to active physical weathering, significant gradients and low projective vegetation coverage of the slopes of these areas. The accelerated expansion of periglacial areas that has taken place in recent decades is explained by climate changes that contribute to the melting of mountain glaciers. The improved methodology of studying the relief transformation processes, the rates of various exogenous processes, and the features of material redistribution along the pathways of sediment transportation from the slopes to the river valley bottoms contributed to a dramatic increase in quantitative assessment of spatio-temporal changes in the relief of the mountain periglacial zone. The article discusses various traditional and contemporary methods and approaches to studying the periglacial zone relief and its changes. They are divided into two groups: methods of stationary and semi-stationary observations of exogenous processes and methods for studying sediment redistribution in catchments. Various directions are highlighted within each group of methods, special attention is paid to the latest techniques. The results of observations of the rates of various exogenous processes occurring in the periglacial zone are generalized. It is shown that the intensity of rockfall-talus processes depends on lithology and frequency of daily air temperature fluctuation through zero °C and varies from 0.02 to 1.6 mm/year. Avalanche abrasion in avalanche trays reaches 40–70 mm/year. The rate depends on the area of the slope catchment, within which avalanches descend, and corresponds to the rate of denudation for the slope catchment equal to 0.01–0.05 mm/year. Maximum soil erosion rates are typical for young moraine slopes, where it reaches 100 mm/year in the first years after the glacier melts, and after 50 years slows down to 7–10 mm/year. The main flux of sediments is delivered from the slopes to the river bottoms by occasionally formed mudflows.

A basin analysis for assessment of the ecological state of groundwater on the Khovu-Aksynskii arsenide–cobalt–sulfide deposit (Tyva Republic) located on the left bank of the Elegest River was combined with field morphometric studies and hydrogeochemical sampling. It was shown that the chemical composition of the groundwater is mostly controlled by the basin organization of the territory. The structural indices of areas, lengths, slopes, and bifurcation calculated for the Khovu-Aksynskii Ravine basin, as well as the geomorphological work indicate that, within its limits the functional type of the third-order basin components changes by removal and accumulation of water and lithodynamic flows from the denudation (in the upper component) to the accumulation (in the middle) and transition (in the integral lower component). According to the type of basin, it was demonstrated that the groundwater chemistry is mostly formed in the middle and lower components of the basin under natural and anthropogenic impacts. Halos that reflect a decrease in the total mineralization (from 0.68 to 0.3 g/L), hardness (from 7.1 to 3.2 mg-eqv/L), and arsenic content (from 0.013 to less than 0.005 mg/L) are formed in the groundwater of the deluvial–proluvial horizon with distance from the contamination sources. The absence of water contamination with ore-forming heavy metals (nickel, cobalt, and copper) typical of the deposit and tailing dumps is explained by the transitional type of the integral component of the catchment basin as well. The results we obtained show the probability of using it in modeling of the conditions of denudation and accumulation of natural and anthropogenic contaminants in the underground aquifers.

During each Heinrich stadial (HS), temperatures in southern Europe typically dropped several degrees during several hundred to few thousand years. We have developed a one-dimensional thermal conduction model that transfers the typical surface temperature anomaly of a HS to a series of hypothetical underlying caves. The results show that with increasing depth, the thermal anomaly is attenuated, the lag time increases, and the signal structure experiences larger modifications. The model suggests that in most cases, it is not acceptable to assume a synchronous thermal variability and similar average temperature values between the surface atmosphere and the cave interior at millennial timescales. We also simulated the thermal impact of the modeled HS on speleothem δ18O records. The outputs of most model scenarios suggest that temperature changes associated with the HS produce δ18O anomalies capable of contributing significantly or even decisively to the speleothem isotope variability. Therefore, despite controls other than temperature often being considered more important when interpreting Pleistocene speleothem δ18O records in temperate climates, this research suggests that temperature is expected to be one of the major controls of δ18O values in most cave sites outside the tropics and should be included as a significant parameter affecting Pleistocene speleothem δ18O records., The lead author of this research (DD-V) received funds from the project “Inter-comparison of Karst Denudation Measurement Methods” (KADEME) (IP-2018-01-7080) financed by Croatian Science Foundation

Meteoric 10 Be ( 10 Be met ) concentrations in soil profiles have great potential as a geochronometer and a tracer of Earth surface processes, particularly in fine-grained soils lacking quartz that would preclude the use of in situ produced 10 Be ( 10 Be in situ ). One prerequisite for using this technique for accurately calculating rates and dates is constraining the delivery, or flux, of 10 Be met to a site. However, few studies to date have quantified long-term (i.e., millennial) delivery rates, and none have determined a delivery rate for an eroding soil. In this study, we compared existing concentrations of 10 Be in situ with new measurements of 10 Be met in eroding soils sampled from the same depth profiles to calibrate a long-term 10 Be met delivery rate. We did so on the Pinedale ( ∼ 21–25 kyr) and Bull Lake ( ∼ 140 kyr) glacial moraines at Fremont Lake, Wyoming (USA), where age, grain sizes, weathering indices, and soil properties are known, as are erosion and denudation rates calculated from 10 Be in situ . After ensuring sufficient beryllium retention in each profile, solving for the delivery rate of 10 Be met , and normalizing for paleomagnetic and solar intensity variations over the Holocene, we calculate 10 Be met fluxes of 1.46 ( ± 0.20) × 10 6 atoms cm −2 yr −1 and 1.30 ( ± 0.48) × 10 6 atoms cm −2 yr −1 to the Pinedale and Bull Lake moraines, respectively, and compare these values to two widely used 10 Be met delivery rate estimation methods that substantially differ for this site. Accurately estimating the 10 Be met flux using these methods requires a consideration of spatial scale and temporally varying parameters (i.e., paleomagnetic field intensity, solar modulation) to ensure the most realistic estimates of 10 Be met -derived erosion rates in future studies.

The grotto rock mass is a type of cave structure, formed under the complex forces of environment, geology, and human interventions. Many scholars have carried out a lot of work in the protection of cultural relics. However, the research on detection and monitoring methods based on the parametric evolution system remains incomplete. In recent years, with the intersection and integration of disciplines, IoT (IoT: Internet of Things) systems and sensor technologies have developed rapidly. Under this background, a new monitoring system suitable for the protection of cultural relics was independently developed and applied to the protection and research work of Yuanjue rock cave, and the system was corrected and improved in practice. In this paper, according to the complex force characteristics of the sandstone roof of the Yuanjue rock cave at Dazu Rock Carvings and the geological conditions. Initially, a detailed survey of the geological conditions of the Yuanjue rock cave area was conducted; furthermore, according to the unique structural and load characteristics of the outer and inner surfaces of the roof, the monitoring methods and principles of each main control factor were explored, while the layout of monitoring points was optimized; finally, based on the microsensing technology, intelligent high-precision sensing hardware was installed and debugged for each main control factor, while the network was formed to form a multisource monitoring IoT system for the roof stability of the circular sense hole. After nearly half a year of continuous monitoring, the deformation and denudation rules of the roof of Yuanjue Cave were revealed, and a new approach of evaluating roof stability was proposed. This research provided technical support and research ideas for monitoring the stability of similar cultural relics.

Цель исследования – выявить приуроченность экзодинамических явлений в Воронежском модельном регионе к высотно-ландшафтным мезозонам равнин. Материалы и методы. Исходными материалами для аналитических обобщений послужили натурные наблюдения на полустационарных полигонах, расположенных в Воронежском Подонье, экспедиционные маршрутные наблюдения, а также материалы дешифрирования космоснимков. Результаты и обсуждение. Полевые материалы, материалы фондов сельскохозяйственных предприятий, полустационарные наблюдения и результаты дистанционного зондирования показывают, что экзодинамические явления в Воронежском модельном регионе очень тесно связаны с высотно-ландшафтной дифференциацией равнинного рельефа. Например, водная и ветровая эрозия распространена повсеместно по территории области. Но чаще всего отмечается в границах возвышенно-денудационной и вершинно-водораздельной мезозонах на Среднерусской и Калачской возвышенностях. На Окско-Донской равнине ветровая эрозия отмечается в местах высокой распашки земель на низменно-гидрогенной мезозоне в верховьях рек Плавица, Битюг, Малый Эртиль. Там, где на Среднерусской возвышенности получила распространение вершинно-водораздельная мезозона (200-250 метров) основные экзодинамические явления – водная эрозия и карстовая денудация. Заключение. Наши многочисленные исследования показывают, что в Воронежском модельном регионе встречается весь перечень экзодинамических явлений, известных в административных областях центра Русской равнины – овражная и водная эрозия, оползни, осыпи, обвалы, карстовая денудация, равнинные сели, камнепады.

We examine the sensitivity of 10Be concentrations (and derived denudation rates), to debris‐flow and anthropogenic perturbations in steep settings of the Eastern Alps, and explore possible relations with structural geomorphic connectivity. Using cosmogenic 10Be as a tracer for functional geomorphic connectivity, we conduct sampling replications across four seasons in Gadria, Strimm and Allitz Creek. Sampling sites encompass a range of structural connectivity configurations, including the conditioning of a sackung, all assessed through a geomorphometric index (IC). By combining information on contemporary depth of erosion and sediment yield, disturbance history and post‐LGM (Last Glacial Maximum) sedimentation rates, we constrain the effects of debris‐flow disturbance on 10Be concentrations at the Gadria sites. Here, we argue that bedrock weakening imparted by the sackung promotes high depth of erosion. Consequently, debris flows recruit sediment beyond the critical depth of spallogenic production (e.g., >3 m), which in turn, episodically, due to predominantly muogenic production pathways, lowers 10Be concentration by a factor of 4, for at least 2 years. In contrast, steady erosion in Strimm Creek yields very stable 10Be concentrations through time. In Allitz Creek, we observe two‐ to fourfold seasonal fluctuations in 10Be concentrations, which we explain as the combined effects of water diversion and hydraulic structures on sediment mixing. We further show that 10Be concentration correlates inversely with the IC index, where sub‐basins characterized by high concentrations (long residence times) exhibit low IC values (structurally disconnected) and vice versa, implying that, over millennial time scales a direct relation exists between functional and structural connectivity, and that the IC index performed as a suitable metric for structural connectivity. The index performs comparably better than other metrics (i.e., mean slope and mean normalized channel steepness index) previously used to assess topographic controls on denudation rates in active unglaciated ranges. In terms of landscape evolution, we argue that the sackung, by favouring intense debris‐flow activity across the Holocene, has aided rapid postglacial reshaping of the Gadria basin, which currently exhibits a topographic signature characteristic of unglaciated debris‐flow systems. © 2020 John Wiley & Sons, Ltd. ISSN:0197-9337 ISSN:1096-9837

The Mufushan massif, as continental intra-plate magmatites located in the Jiangnan-Xuefeng orogenic belt of the South China. The Mufushan massif constitutes the largest Mesozoic intrusive complex, intruded the Mesoproterozoic Lengjiaxi Formation. Multiple geochronometric dating was used to reconstruct their evolution from emplacement to exhumation. The Mufushan granitoids were emplaced at ∼150 Ma (U-Pb zircon) as post-orogenic magmatites contributing to Triassic crustal thickening. Onset of regional extension at ∼128 Ma (40Ar/39Ar white mica and biotite) manifests a tectonic regime switch. Intense exhumation prior to ∼55 Ma was followed by slow denudation and peneplanation for the next 37 Ma (∼55’18 Ma). Accelerated cooling since ∼18 Ma may have been caused by a far-field effect of the collision between India-Asia Plate or the Pacific-Plate subduction. Through a multi-geochronometric approach, this study provides a new comprehensive model for the cause of the intra-plate magmatism formation in the South China, and also established a reliable geochronological framework of the post-orogenic tectonic evolutions of the Jiangnan-Xuefeng orogenic belt.

Este trabalho objetiva compreender o quadro geomorfológico da porção terminal do baixo curso do rio Paraíba do Norte – PB, mediante a classificação e diferenciação cartográfica das unidades de relevos presentes na área de estudo. Adotou-se para o presente trabalho a escala de 1:25.000 que permitiu identificar os seis táxons propostos na metodologia de Ross (1992). O estudo possibilitou conhecer com maior nível de detalhe a geometria e os padrões de relevo existentes na região, onde se destacaram áreas de acumulação e denudação, dentre elas: planícies marinhas, fluviais e flúvio marinhas, formas de terraços e vertentes, falésias, praias, barras arenosas, bancos de areia, paleolinhas de praias, recifes, lagoas antropogênicas, lagunas, dolinas e glacis de sedimentação, além de formas de relevos tabulares e convexos que modelam os tabuleiros litorâneos da costa paraibana.

Cirque erosion contributes significantly to mountain denudation and is a key element of glaciated mountain topography. Despite long-standing efforts, rates of rockwall retreat and the proportional contributions of low-, mid- and high-magnitude rockfalls have remained poorly constrained. Here, a unique, terrestrial-lidar-derived rockfall inventory (2011–2017) of two glaciated cirques in the Hohe Tauern range, Central Alps, Austria, is analysed. The mean cirque wall retreat rate of 1.9 mm a−1 ranks in the top range of reported values and is mainly driven by enhanced rockfall from the lowermost, freshly deglaciated rockwall sections. Retreat rates are significantly elevated over decades subsequent to glacier downwasting. Elongated cirque morphology and recorded cirque wall retreat rates indicate headward erosion is clearly outpacing lateral erosion, most likely due to the cataclinal backwalls, which are prone to large dip-slope failures. The rockfall magnitude–frequency distribution – the first such distribution derived for deglaciating cirques – follows a distinct negative power law over 4 orders of magnitude. Magnitude–frequency distributions in glacier-proximal and glacier-distal rockwall sections differ significantly due to an increased occurrence of large rockfalls in recently deglaciated areas. In this paper, the second of two companion pieces, we show how recent climate warming shapes glacial landforms, controls spatiotemporal rockfall variation in glacial environments and indicates a transient signal with decadal-scale exhaustion of rockfall activity immediately following deglaciation crucial for future hazard assessments.

Tectonically active high relief areas are proposed to have a substantial impact on climate regulation throughout the Cenozoic. Here, we present lithium (Li) isotope data of the dissolved load and suspended particulate material from the basins of the Yalong River and the Jinsha River, which drain the high-relief borders of the eastern Tibetan Plateau and constitute the headwaters of the Yangtze River. Dissolved δ7Li values are relatively low and constant in the Jinsha River mainstream (+6.8‰ to +9.7‰) compared to the higher and downstream increasing values in the Yalong River mainstream (+10.8‰ to +17.5‰). Furthermore, dissolved δ7Li values in the major tributaries of the Jinsha and Yalong River are highly variable and increase downstream from +11.4‰ to +29.4‰ and from +9.0‰ to +23.6‰, respectively. Robust correlations between Li, Na, and Cl concentrations identify that evaporite dissolution in the uppermost headwaters of the Jinsha River basin controls the Li budget and riverine δ7Li values of the mainstream and has a significant impact on dissolved Li in the Yangtze River. In contrast to the Jinsha River mainstream, dissolved Li in the Yalong River mainstream and the Jinsha and Yalong River tributaries are dominantly derived from the dissolution of silicates. δ7Li variations in the Yalong River basin and the Jinsha tributaries reflect little Li uptake by clays in the upper reaches and more Li uptake by clays in the lower reaches of the river basins. SWR/D ratios (where SWR is the chemical silicate weathering rate, and D is the total denudation rate) highlight an intermediate silicate weathering intensity under a kinetically limited weathering regime for the study area. However, positive correlations between dissolved δ7Li value and silicate weathering intensity proxies (such as Si/(Nasil + K) and K/(Nasil + K)) indicate an increasing weathering intensity downstream. A positive correlation between dissolved δ7Li values and the annual precipitation and a negative one between δ7Li values and elevation indicates that larger annual precipitation under a flattening relief results in a stronger silicate weathering intensity, thus, more Li uptake in clays and higher riverine δ7Li values in the lower reaches. Compared to the lower reaches of Yangtze River basin (∼+20‰), lower dissolved δ7Li values in its headwater of this study suggest that the increase in δ7Li of seawater over the Cenozoic is influenced by weathering in floodplains that developed due to erosion of high mountains, rather than weathering of mountain belts itself. Combined with silicate weathering rates of the eastern border of the Tibetan Plateau, the highest riverine δ7Li values in its catchments come along with the highest silicate weathering rates and high CO2 consumption, suggesting that a more elevated topography may have an important role in the drawdown of CO2 during the Cenozoic.

The runoff-sediment relationship in the Yellow River Basin of China is still grim. People pay more and more attention to non-point source (NPS) pollution caused by surface pollutants migrating into the receiving water body with rainfall runoff. The particulate load of pollutants adsorbed in the soil and sediment by erosion and denudation and migration into water is also quite serious. It is necessary to deeply analyze the quantitative relationship between particulate nitrogen and phosphorus (PN/PP) load and soil loss. The soil erosion estimation of different administrative units in the study basin is obtained by the revised universal soil loss equation (RUSLE). The spatial distribution and the variation characteristics at different slopes and different land use of PN/PP load are discussed. An empirical equation of particulate organic load is used to calculate the PN/PP load. The results show that the multi-annual average erosion modulus of the basin is 358.33 t/(km2∙a); the multi-annual average soil erosion reaches 9.62 million tons. The PN/PP load caused by soil loss reaches 11,107.1 t and 7909.3 t, and the export coefficients are 4.13 kg/hm2 and 2.94 kg/hm2, respectively. Spatial distribution of the PN/PP load is in step with the soil erosion distribution. Soil erosion is prone to occur in the region under the slope of 8 ~ 25°, the NPS load of PN/PP are relatively large, and the average export coefficients of PN/PP are 7.17 kg/hm2 and 5.06 kg/hm2. With the increase of the slope, the PN/PP load export coefficient increases first and then decreases. Agricultural land (AGRL), forest land (FRST), and pasture (PAST) are the land use types that contribute the most to the PN/PP load and soil erosion, and the average export coefficients of PN/PP are 4.54 kg/hm2 and 3.23 kg/hm2, respectively. The variability of natural elements, the unevenness and heterogeneity of spatial distribution, and the heavy involvement of human activities will have a conspicuous impact on the soil erosion and NPS pollution processes in the basin. The research on the influence of single factor and combined factors on NPS pollution process can be strengthen and provides scientific theoretical basis for formulating reasonable and efficient water and soil conservation measures and NPS pollution control scheme, so as to achieve effective control and scientific management of environment pollution.

The Huizhou Movement refers to the Middle Eocene tectonic transition from the early to the late Wenchang Rifting stage (about 43 Ma ago) in the Pearl River Mouth Basin. Based on seismic reflection, drilling, logging and geological data, fault characteristic analysis, denudation thickness recovery, magmatism statistics, regional tectonic dynamics comparison and other methods are used to reveal the characteristics, properties and dynamic mechanism of the Huizhou Movement. The Huizhou Movement mainly shows the North-South transition of rifting and the migration along the faults, basement uplift, magmatic diapir and stratigraphic denudation. It is believed that the Huizhou Movement is a comprehensive reflection of plate interaction and lithospheric thinning process in the Pearl River Mouth Basin, which is closely related to the transition of lithosphere from initial rifting to rapid thinning, the India-Eurasia hard collision and the change of subduction direction of the Pacific plate. The Huizhou Movement has significant influence and control on the Paleogene hydrocarbon-generating sags and the development of hydrocarbon source rocks, sedimentary system and deep high-quality reservoir, hydrocarbon migration and accumulation in the Pearl River Mouth Basin.

Chemical weathering in the Himalayan river basins is among the highest in the world and has received vast research attention related to past climate change. Many early estimates of chemical weathering are based on a small number of water property data that ignore those spatial and seasonal variations. Therefore, this study analyzed spatial and seasonal variations in chemical weathering in the Mekong Basin, where the geology, climate, and hydrologic cycle of the basin vary significantly from the lower to upper reaches and from dry to rainy seasons. We separately estimated the origins of dissolved elements and potential CO2 consumption rates using the numerous chemical compositions of river water throughout the entire basin and in both seasons. The CO2 consumption rate in the rainy season is three to five times that in the dry season that may be due to the high temperature and precipitation. Despite the low temperatures and dryness of the upper and middle basins, the CO2 consumption rate is approximately twice that in the lower reaches; this can be attributed to active physical denudation in steep mountainous areas which increases the surface area for water–rock interactions. The total CO2 consumption obtained by combining each season and basin was 48‒70 × 109 mol/a and 148‒159 × 109 mol/a for silicate and carbonate weathering, respectively, which are almost half the values of previous estimates. Our results suggest that seasonally and spatially separated evaluations are important for generating estimates of chemical weathering in large Himalayan rivers.

Karst aquifers represent the most important renewable sources of drinking water. Because anthropogenic influences threaten the integrity of karst aquifers, it is important to determine the soil erosion and karst denudation rates. In order to study the complex signs of degradation processes of the karst, a paleodoline (paleo-polje) was selected near to the county seat Veszprém, Hungary. It was found that gamma radiation measurements can be a useful tool to detect the level of soil erosion since the low gamma radiation indicates the surface proximity of the carbonate bedrock. The level of gamma radiation also predicts the potential agricultural usability of a site. Both the patterns of contamination and the erosion attack zone are strongly defined by the relief. The gullies and the deepest parts of the karstic landscape are the traps of organic materials and pollutants. The amounts of 40K and its decay products originate from the covering sediment and negatively correlate with the soil depth. In the case of covered karsts, the measuring of the concentration of radionuclides and field gamma-ray dose measurement together can characterize the general horizontal and vertical trends of soil erosion, the potential land use, and the vegetation.

The restoration of the denudation thickness is the basis for quantitatively analyzing the basin burial history, thermal evolution history and hydrocarbon accumulation conditions. The well data is not sufficient to do this in the southern Lishui Sag with only 5 wells, so the new, high-quality three-dimensional (3D) seismic data is essential. The methods employed to determine the eroded thicknesses of key unconformities in the study area are the mudstone acoustic time difference (AC) method, vitrinite reflectance (Ro%) method and stratigraphic trend comparison method. On the basis of the structural evolution, the restoration of the paleogeomorphology is carried out. The results show that the Wenzhou formation (E2w) in the entire study area has been all denuded. The denudation thickness is in the range of 0-550 m, and decreases gradually from west, thicker than 200 m, to east. The erosion of the upper Lingfeng formation (E11) are mainly occurred in the N-P-1 structural trap (N-P-1), the N-P-2 structural trap (N-P-2) and the N-P-3 structural trap (N-P-3). Among them, the eroded area in N-P-1 (near well S-1) and N-P-2 is 200-230km2, and the denudation thickness is 0-600m, which increases from south to north, even up to 200-400m in the region around well S-1. In N-P-3, the extent of denudation is 30-50 km2, and the denudation thickness is 0-400m. In the early stage of the upper E11, one north-south strike slip fault began to develop in the southern study area. Affected by this fault, the southern Lingfeng bulge was offset, forming a gorge, and the eastern and western sides of the concave belt connected to each other. On the basis of the paleo-geomorphological characteristics, it is shown that the sedimentary center of the west subsag began to migrate to the south.

The study area is located on a tectonic belt shaped by the segments of Bitlis Zagros Suture Zone in the Eastern Anatolia Compression Regime Region, which is one of the morphotectonic regions of Anatolia. At the same time, the main structure of the area to the east of the Toros Orogen Belt consists of a curved structure extending in NW-SE direction. However, the dislocations of the Alp Orogenesis, which were exacerbated by the paroxysmal phases in the post-Miocene period, changed the general morphographic structure. This change occurred by fractures formed due to the rigid characteristics of the Jurassic-Cretaceous massive limestones. Although the dominant structure around the study area is curved, the last movement has been shaped by faulting and many shapes of fault geomorphology have enriched the geomorphological landscape of the region. The aim of this study was to determine the tectono-geomorphological forms in the Sinebel Gorge Valley and its surroundings, and to reveal its lithological, tectonic relations and its effects on the landscape. As a result of field and literature studies, several geomorphic elements reflecting fracture tectonics were identified in the study area: hanging valleys, hanging cave, fault valleys, fault perpendicularty, stepped topography, faceted hills, directional lapya, landslide, antesedant valley, sequential scree cones, cut hills, travertine, shifted valleys slope, slope fractures. As a result of these investigations, it is understood that these shapes are formed depending upon the compression and stress tectonics. The geomorphological landscape of the area has a tectono-dynamic character and later became a polygenic topography with the coming into play of denudation processes.

Thick sediments from foreland basins usually provide valuable information for understanding the relationships between mountain building, rock denudation, and sediment deposition. In this paper, we report environmental magnetic measurements performed on the Miocene sediments in the Subei Basin, northeastern Tibetan Plateau. Our results show two different patterns. First, the bulk susceptibility and SIRM, ARM, and HIRM mainly reflect the absolute-concentration of magnetic minerals; all have increased remarkably since 13.7 Ma, related to provenance change rather than climate change. Second, the ratios of IRM100mT/SIRM, IRM100mT/IRM30mT, and IRM100mT/IRM60mT, together with the redness and S ratio, reflect the relative-concentration of hematite, being climate-dependent. Their vertical changes correlate in general with the long-term Miocene climatic records of marine oxygen isotope variations, marked by the existence of higher ratios between 17 and 14 Ma. This may imply that global climate change, rather than uplift of the Tibetan Plateau, played a dominant role in the long-term climatic evolution of the Subei area from the early to middle Miocene.

The vast geomorphological heritage of the outstanding German scientist Albrecht Penck mainly related to general geomorphology, the geomorphology of mountains, climatology, hydrology and hypsometric maps, has so far been insufficiently known by Soviet/Russian geomorphologists. His fundamental studies are related to the last twenty years of the 19 th and the first quarter of the 20 th century. He was engaged in fieldwork in Europe–mainly in the Alps and the Danube basin, the mountains of Spain, North Morocco, and also in Canada, Australia, China, Japan and some other countries, and created the first classification of climates. Together with Eduard Bruckner, he was co-author of a concept of ancient glaciation; they were the first to identify the four ice ages of the European Pleistocene (Gunz, Mindel, Riss, Wurm). Albrecht Penck enriched geomorphology with the concept of “summit level of denudation”. He was convinced that the heights of the snow- and forest-line were responsible for mountain heights, the rate of denudation and therefore, determine the height of the summit level of denudation ( gipfelflur ) for each climate. Later, he moved away from these ideas and introduced the term “summit surface” poining to the constant eleveation of the summit levels without explaining the phenomenon per se. Academician Konstantin Markov spoke of Albrecht Penck as one of the prominent geomorphologists with rich scientific heritage and as “Nestor the Chronicler of foreign geomorphology”. For a long time Penck was a Director of the Institute and Museum of Oceanography in Berlin and a member of the Royal Swedish Academy of Sciences. He was well-known in the academic circles of Russia, some of his works were published in Russian; he regularly visited Russia and was elected honorary member of the Moscow Society of Naturalists, Russia’s oldest society of nature explorers set up in 1805. In 1859, von Humboldt-Ritter Stiftung (the Humboldt-Ritter Foundation) was set up in Germany and actively functioned after their deaths. After Pencks death died in 1945 the foundation was transformed to Humboldt-Ritter-Penck Foundation, and has been active up to now days.

Introduction. Climate warming, which is currently observed in the Arctic, has the potential to intensify chemical denudation in river basins partially or completely located within permafrost. In order to test this hypothesis, we investigated the longterm dynamics of the rivers’ ion runoff in the Pechora River basin, 42 % of which are located within permafrost. Methods. To study changes in the chemical denudation intensity in nonstationary climate, we analyzed data of systematic observations over the main ion concentrations from 1985 to 2017 in the Pechora River outlet (Naryan-Mar) and its tributaries (Usa, Adzva, Kolva, Sula rivers). The intensity of chemical denudation in the Pechora River basin was assessed in terms of ion runoff. The probable reasons for its changes — water content and concentrations of macrocomponents — were also analyzed. Results. The ion-salt composition of Pechora River water is mainly determined by the dissolution of carbonate minerals in the underlying rocks. Calculations and comparison of ion runoff moduli showed that the studied rivers are comparable in terms of the chemical denudation intensity in catchments. The exceptions were the Sula and Kolva rivers, where, with the river runoff, a relatively high amount of chlorides and hydrocarbonates is carried. Contrary to the initial assumptions about the possible intensification of the chemical denudation process under the conditions of climate warming, we found a decrease in the sulfate runoff moduli in all rivers. In addition to that, individual changes in the runoff moduli for other main ions are observed for the studied rivers. Conclusion. In modern conditions, the chemical denudation intensity remains at the level of the end of the last century, and the long-term dynamics of the Pechora River ion runoff correlates in time with the variability of anthropogenic factors, in particular, wet sulfate deposition with atmospheric waters.

Geological records indicate that the hyper-aridity in the Atacama Desert has prevailed since at least the mid-Miocene, with shorter periods of increased humidity punctuating long-term aridity. The 7-m-high accumulation of colluvial sediments at the Salar Grande (21°S/70°W) studied here provides a key palaeoclimate record to understand hillslope dynamics and its relation to humid periods. While 10Be surface exposure ages point to long-term surface stability of the flat upslope surface, a combination of humidity-driven soil creep, overland flow and soil creep related to seismic shaking, caused denudation of the hillslope and accumulation of several metres of colluvium over much shorter timescales during the last 130 ka. A robust chronology for the hillslope sediments has been established by using Infrared Stimulated luminescence (pIR-IR225 protocol) on K-feldspar extracts from nine samples collected within the accumulation. A series of tests has been carried out to confirm the suitability of the method. The estimated ages indicate accelerated sedimentation at 35–80 ka, and 100–130 ka, which are interpreted as periods with more humid climate conditions than present. These findings agree with climate variations in the hyper-arid Atacama indicated by the activity of coastal alluvial fans and river catchments.

The Zemo Imereti (Chiatura) Structural Plateau covers the easternmost part of the western Georgia limestone belt and is the only region of the platform karst in the entire Caucasus. Zemo Imereti Plateau’s complex structural studies revealed that the karst landscape has been completely transformed due to human strong economic activities, mainly related to the manganese unplanned, predatory extraction. The ore mining process completely destroyed the soil and vegetation cover thus creating “anthropo-badlands”. Due to manganese open-cast mining, the layers located over limestones are almost totally removed and heavy rains stipulate intense washout of substances from loose rocks. Intense washout of manganese extracted from mines and high contamination of river water streams take place directly in the river beds. Karst sinkholes and wells are common in the plateau, which are often used as waste fills-storages by the local population. Contaminated underground karst waters flowing into the above mentioned landforms are directly related to the karst springs used by the population and occasionally cause their turbidity and contamination, which is also confirmed by our indicator tests. As a laboratory study of the samples showed, mineralization of underground karst waters in the study area is 1.5 - 3 times higher than similar values in neighboring karst areas, which should be explained by the widespread of manganese open pits in the feeding basins of underground karst waters. According to the materials obtained from our surveys and calculations carried out, karst (chemical) denudation (surface 64.2 - 190.6 m3/km2/year, underground 1.5 - 117.0 m3/km2/year) has been increased in the study area than in other karst regions of Georgia, which is also related to technologic factors.

The utility of speleothems as environmental and geological archives has greatly expanded with recent advances in geochronology. Here we reevaluate their ability to constrain late Cenozoic uplift in karst terranes. Using combined U-Th and U-Pb speleothem chronologies for the Buchan karst along the passive margin of southeastern Australia, we calculate a maximum uplift rate of 76 ± 7 m m.y.−1 maintained over the past 3.5 m.y. The timing and extent of this process is consistent with independent constraints on Neogene uplift in Australia, possibly in response to increased plate-boundary strain with New Zealand. Speleothem chronologies provide highly precise age control on individual events and the potential for near-continuous records across long periods of geological time, complementing and expanding upon existing uplift proxies.

Disentangling the influence of bedrock erodibility from the respective roles of climate, topography and tectonic forcing on catchment denudation is often challenging in mountainous landscapes due to the diversity of geomorphic processes in action and of spatial/temporal scales involved. The Dora Baltea catchment (western Italian Alps) appears the ideal setting for such investigation, since its large drainage system, extending from the Mont Blanc Massif to the Po Plain, cuts across different major litho-tectonic units of the western Alps, whereas this region has experienced homogeneous climatic conditions and glacial history throughout the Quaternary. We acquired new 10Be-derived catchment-wide denudation rates from 18 river-sand samples collected both along the main Dora Baltea river and at the outlet of its main tributaries. The inferred denudation rate results vary between 0.2 and 0.9 mm/yr, consistent with values obtained across the European Alps by previous studies. Spatial variability in denudation rates was statistically compared with topographic, environmental and geologic metrics. 10Be-derived denudation records do not correlate with the distribution of modern precipitation and rock geodetic uplift. We find, rather, that catchment topography, in turn conditioned by bedrock erodibility (litho-tectonic origin) and glacial overprint, has the main influence on denudation rates. We calculated the highest denudation rate for the Mont Blanc Massif, whose granitoid rocks and long-term tectonic uplift support steep slopes and high relief and thus favour intense glacial/periglacial processes and recurring rock fall events. Finally, our results, in agreement with modern sediment budgets, demonstrate that the high sediment input from the Mont Blanc catchment dominates the Dora Baltea sediment flux, explaining the constant low 10Be concentrations measured along the Dora Baltea course even downstream the multiple junctions with tributary catchments.

Long-term landscape evolution is controlled by tectonic and climatic forcing acting through surface processes. Rivers are the main drivers of continental denudation because they set the base level of most hillslopes. The mechanisms of fluvial incision are thus a key focus in geomorphological research and require accurate representation and models. River incision is often modeled with a stream power model (SPM) based on the along-stream evolution of drainage area and channel elevation gradient but can also incorporate more complex processes such as threshold effects and statistical discharge distributions, which are fundamental features of river dynamics. Despite their importance in quantitative geomorphology, such model formulations have been confronted with field data only in a limited number of cases. Here we investigate the behavior of stochastic-threshold incision models across the southeastern margin of the French Massif Central, which is characterized by significant relief and the regular occurrence of high-discharge events. Our study is based on a new dataset combining measurements of discharge variability from gauging stations, denudation rates from 34 basins from 10Be cosmogenic radionuclide (CRN) concentration measurements in river sediments, morphometric analysis of river long profiles, and field observations. This new dataset is used for a systematic investigation of various formulations of the SPM and to discuss the importance of incision thresholds. Denudation rates across the SE margin of the Massif Central are in the 20–120 mm kyr−1 (equivalent to mm/ka in the figures) range, and they positively correlate with slope and precipitation. However, the relationship with the steepness index is complex and supports the importance of taking into account spatial variations in parameters (D50, discharge variability k, runoff) controlling the SPM. Overall, the range of denudation rate across the margin can mainly be explained using a simple version of the SPM accounting for spatially heterogeneous runoff. More complex formulations including stochastic discharge and incision thresholds yield poorer performances unless the spatial variations in bedload characteristics controlling incision thresholds are taken into account. Our results highlight the importance of the hypotheses used for such a threshold in SPM application to field studies and notably the impact of actual constraints on bedload size.

IF 4.40; Q1); International audience; An emerged coral reef terrace sequence flanks the northern coast of Sumba Island in Indonesia. The sequence was created by the joint effects of uplift and Quaternary sea level oscillations. Since its emergence, it undergoes chemical erosion, which is facilitated by its carbonate lithology. The morphology is dissected by multiple catchments drained by deep canyons, whose stream profiles display several knickpoints. We applied a multi-methods approach using high-resolution topographic data (Pleiades imagery), geomorphological analysis and denudation rates derived from 36Cl cosmogenic nuclide concentrations to characterize the dynamics of these coastal drainages. We specifically investigate (1) the channel response to eustatic forcing, by analyzing knickpoint dynamics along a longitudinal river profile, and (2) the control of internal and external forcing over the catchment-scale erosion. Firstly, knickpoints form at the distal edge of the emergent reef at each regressive stage following a sea level highstand. The knickpoint propagates and rotates upward by regressive erosion. Knickpoint propagation rate decreases sharply over time until it becomes negligible before the next sea-level rise, which implies a marked decline in knickpoint retreat rate before its resorption. We attribute the inability of the river at Cape Laundi to fully propagate eustatic oscillations to its low stream discharge and low sediment supply, related to its small drainage area, to the karstic nature of the coral reef terraces composing the sequence, and to the high frequency of eustatic forcing. Secondly, average denudation rates calculated from 36Cl cosmogenic nuclide concentrations of sands collected at the outlet of five catchments draining the sequence amount to 69 ± 8 mm·ka−1. We emphasize the role of canyon areas in driving the denudation of the major catchments. However, no first-order correlation has been observed between catchment metrics, uplift rates and denudation rates. Finally, our correlations between catchment finite eroded volumes and uplift rates highlight the tendency of catchments to widen with low uplift rate and to lengthen while incising the sequence deeply with higher uplift rates.

Observational data of coastal change over much of the Arctic are limited largely due to its immensity, remoteness, harsh environment, and restricted periods of sunlight and ice-free conditions. Barter Island, Alaska, is one of the few locations where an extensive, observational dataset exists, which enables a detailed assessment of the trends and patterns of coastal change over decadal to annual time scales. Coastal bluff and shoreline positions were delineated from maps, aerial photographs, and satellite imagery acquired between 1947 and 2020, and at a nearly annual rate since 2004. Rates and patterns of shoreline and bluff change varied widely over the observational period. Shorelines showed a consistent trend of southerly erosion and westerly extension of the western termini of Barter Island and Bernard Spit, which has accelerated since at least 2000. The 3.2 km long stretch of ocean-exposed coastal permafrost bluffs retreated on average 114 m and at a maximum of 163 m at an average long-term rate (70 year) of 1.6 ± 0.1 m/yr. The long-term retreat rate was punctuated by individual years with retreat rates up to four times higher (6.6 ± 1.9 m/yr; 2012–2013) and both long-term (multidecadal) and short-term (annual to semiannual) rates showed a steady increase in retreat rates through time, with consistently high rates since 2015. A best-fit polynomial trend indicated acceleration in retreat rates that was independent of the large spatial and temporal variations observed on an annual basis. Rates and patterns of bluff retreat were correlated to incident wave energy and air and water temperatures. Wave energy was found to be the dominant driver of bluff retreat, followed by sea surface temperatures and warming air temperatures that are considered proxies for evaluating thermo-erosion and denudation. Normalized anomalies of cumulative wave energy, duration of open water, and air and sea temperature showed at least three distinct phases since 1979: a negative phase prior to 1987, a mixed phase between 1987 and the early to late 2000s, followed by a positive phase extending to 2020. The duration of the open-water season has tripled since 1979, increasing from approximately 40 to 140 days. Acceleration in retreat rates at Barter Island may be related to increases in both thermodenudation, associated with increasing air temperature, and the number of niche-forming and block-collapsing episodes associated with higher air and water temperature, more frequent storms, and longer ice-free conditions in the Beaufort Sea.

The Late Miocene-Pliocene Dhok Pathan Formation (DPF) fluvial sequence of Eastern Sulaiman Foldbelt and Thrust Belt (SFTB) has different lithofacies of sandstone and mudstone deposited in the Himalayan foredeep basin. The present study deals with detailed geochemical analyses of DPF to deduce its provenance, weathering, and tectonic settings. The geochemical data of major oxides plot on scatter diagram shows that the sandstones of DPF are predominantly Arkose-Subarkose and Litharenite-Sublitharenite which were mainly sourced from granitic composition and deposited in fluvial conditions under semi-arid to arid climate. The low elemental ratios of Ni/Co and Cu/Zn indicate oxic conditions during deposition. The mudstone’s ICV values are 1.44 indicating that the source area was influenced by moderate to high weathering. The geochemical analysis indicates lower values of Zr, Nb, Y, and Y/Ni ratio in studied area which point out the existence of ultramafic/mafic sequence in source area. The tectonic discrimination diagrams depict active continental margin tectonic settings for provenance of DPF with partial influx from Continental and Oceanic Island Arc. The present study concludes that clastic rocks of DPF were mainly sourced from Himalayan orogeny with partial influx of Kohistan-Ladakh arc and subsequent deposition in Himalayan foredeep basin which coincides with regional tectonic scenario. Interpretation of paleoenvironments and basin tectonics by geochemical analysis will help to delineate the poorly understood uplift and denudation history in SFTB.

The Qinshui Basin is in the Central Orogenic Belt of the North China Craton (NCC), and the production of coalbed methane accounts for 70% of China’s total coalbed methane output. Aiming at the unclear dynamic causes of large-scale coalbed methane accumulation in the basin and the unclear response relationship with the destruction of the NCC, we present joint illite crystallinity and vitrinite reflectance study across the Zijin Mountain and Qincan 1 wells of the Qinshui Basin, respectively. Inverse modeling suggested that tectono-thermal events occurred during the Early Cretaceous, associated with the maximum burial depth and heat flow. The maximum paleo-geothermal temperature and gradient reconstruction results recorded at the Carboniferous strata are 180–190°C and 6.5°C/100 m. The denudation thicknesses recorded by illite crystallinity of Zijinshan and the vitrinite reflectance of the Qincan 1 Well are 3,180.63 m and 3,269.32 m, respectively. We propose that the Qinshui Basin was affected by the extensional environment of the NCC, which caused deep lithospheric thinning and magma upwelling, and a tectono-thermal event occurred during the Early Cretaceous in Qinshui Basin. In addition, the accumulation of coalbed methane, triggered by a tectono-thermal event during the Early Cretaceous, is consistent with the early Cretaceous accumulation and mineralization events in the NCC. Overall, our results reflect the subduction event influence of the western Pacific plate into the East Asian continental plate on the tectono-thermal history of the Central Orogenic Belt of the NCC, which is theoretically significant for clarifying the thermal lithospheric thickness and rheological structure of the basin, as well as the evolutionary history of coalbed methane, and the basin response relationship to the destruction of the NCC.

(IF 4.45: Q1); International audience; The emerged coral reef terrace sequence at Cape Laundi, on the north coast of Sumba Island (Indonesia), with at least 18 successive strandlines, remains poorly dated in spite of numerous previous data. The age discrepancies within these coral reef terraces (CRTs) were previously explained by their polycyclic nature, triggered by marine erosion and reoccupation of old coral colonies by new ones. This study aims at highlighting these processes, as well as the continental denudation that participates in the partial stripping of the thin superficial coral reef layer overlying the pre-existing surface, exhuming older coral colonies. For this purpose, we use a combined analysis of 36Cl cosmogenic concentrations, new 230Th/U ages, and previous dating in order to quantify denudation rates affecting the sequence and to highlight the role of marine erosion in reworking the lowest CRT surface. Our results demonstrate that 1) the lowermost CRT is composite, i.e., formed by different reefal limestone units constructed and eroded during successive highstands of the last interglacial, 2) following the last deglaciation, this CRT has been subjected again to coastal erosion and reoccupation during the Mid Holocene highstand, 3) its distal edge is affected by the current marine erosion and shows denudation rates higher by one to two orders of magnitude (from 279 ± 0.4 to 581 ± 0.4 mm ka−1) than the continental denudation values of higher CRTs (14.7 ± 8.3 mm ka−1 on average), 4) at the scale of a single CRT surface, variations in continental denudation rates are caused by epikarstification roughness, and 5) the distal edges have the highest continental denudation rate due to diffusion and regressive erosion produced by the runoff occurring along the steep downward cliff.

Late Paleocene deposition of an organic-rich sedimentary facies on the continental shelf and slope of New Zealand and eastern Australia has been linked to short-lived climatic cooling and terrestrial denudation following sea-level fall. Recent studies have confirmed that the organic matter in this facies, termed Waipawa organofacies, is primarily of terrestrial origin, with a minor marine component. It is also unusually enriched in δ13C. In this study we aim to determine the cause or causes of this enrichment. For Waipawa organofacies and its bounding facies in the Taylor White section, Hawkes Bay, paired palynofacies and δ13C analysis of density fractions indicate that the heaviest δ13C values are associated with degraded phytoclasts (woody plant matter) and that the 13C enrichment is partly due to lignin degradation. Compound specific δ13C analyses of samples from the Taylor White and mid-Waipara (Canterbury) sections confirms this relationship but also reveal a residual 13C enrichment of ~ 2.5 ‰ in higher plant biomarkers (n-alkanes and n-alkanoic acids) and 3–4 ‰ in the subordinate marine component, which we interpret as indicating a significant drawdown of atmospheric CO2. Refined age control for Waipawa organofacies indicates that deposition occurred between 59.2 and 58.4 Ma, which coincides with a Paleocene oxygen isotope maximum (POIM) and the onset of the Paleocene carbon isotope maximum (PCIM). This timing suggests that this depositional event was related to global cooling and carbon burial. This relationship is further supported by published TEX86-based sea surface temperatures that indicate a pronounced regional cooling during deposition. We suggest that reduced greenhouse gas emissions from volcanism and accelerated carbon burial related to several tectonic factors and positive feedbacks resulted in short-lived global cooling, growth of ephemeral ice sheets, and a global fall in sea level. Accompanying erosion and carbonate dissolution in deep sea sediment archives may have hidden the evidence of this "hypothermal" event until now.

Long-term erosion rates in Tasmania, at the southern end of Australia’s Great Dividing Range, are poorly known, yet such knowledge is critical for making informed land-use decisions and improving ecological health of coastal ecosystems. Here, we present the first quantitative, geologically-relevant estimates of erosion rates for the George River basin, in northeast Tasmania, based on in-situ produced 10Be (10Bei) measured from stream sand at two trunk channel sites and seven tributaries (average 10.5 mm kyr−1). These new 10Bei-based erosion rates are strongly related to mean annual precipitation rates and elevation, and we suggest that the current East-West precipitation gradient across George River greatly influences erosion in northeast Tasmania. This stands in contrast to erosion rates along the mainland portions of Australia’s Great Dividing Range, which are more strongly related to basin slope. We also extract and measure meteoric 10Be (10Bem) from sediment grain coatings of the stream sand at each site, which we use to estimate 10Bem-based erosion and denudation rates for George River. 10Bem based erosion and denudation metrics, particularly those from the central and eastern tributaries, are also closely related to elevation and precipitation in the same manner as 10Bei erosion rates. Although 10Bem-based denudation rates replicate 10Bei erosion rates within a factor of two, 10Bem-based erosion rates are systematically 5–6x higher than 10Bei erosion rates. 10Bem erosion and denudation metrics for the westernmost headwater catchments are significantly lower than expected and have likely been affected by intensive and widespread topsoil erosion related to forestry, which delivers large volumes of sediment rich in 10Bem to tributary streams. The 10Bei erosion rates presented in this study may be useful for land managers seeking to restore ecological health of Tasmania’s estuaries by reducing sediment input to levels prior to landscape disturbance.

The western Korean Peninsula preserves evidence for multiple Proterozoic to Phanerozoic orogenic processes along the convergent continental margins. After the Late Palaeozoic to Early Mesozoic coll...

International audience; Laterites preserved on both sides of the Western Ghats Escarpment of Peninsular India have formed by long-term lateritic weathering essentially after India-Seychelles continental break up following Deccan Traps emplacement (c. 63 Ma ago). Supergene manganese ores of the Western Ghats were formed on Late Archean manganese protores. Among Mn oxides composing the ores, cryptomelane (K-rich Mn oxide) was characterized and dated by 40Ar/39Ar geochronology. Measured ages complement those previously obtained in other South-Indian manganese ores from the hinterland plateau (Bonnet et al., 2016) and further document three major weathering periods, c. 53-44 Ma, c. 39-22 Ma, and c. 14-10 Ma, the later being documented for the first time in India. These periods coincide with global paleoclimatic proxies and date the lateritic weathering of three successive paleolandscapes of the Western Ghats that evolved under slow denudation (c. 8 m/myr) over the last 44 Myr and were mostly incised during the Neogene (< 22 Ma). That indicates the Western Ghats are a relict of a South Indian plateau preserved at the headwaters of very long east-flowing river systems and above the Western Ghats escarpment. Topography and denudation history of this landscape do not require Neogene tilt of the Peninsula as recently proposed.

Low-temperature thermochronology (LTT) is commonly used to investigate onshore records of continental rifting and geomorphic evolution of passive continental margins. The SE Australian passive margin, like many others, has an elevated plateau separated from the coastal plain by an erosional escarpment, presumed to originate through Cretaceous rifting prior to Tasman Sea seafloor spreading. Previous LTT studies have focused on reconciling thermal histories with development of the present-day topography. New apatite LTT data along an escarpment-to-coast transect define a classic “boomerang” (mean track length vs. fission-track age), indicating variable overprinting of late-Palaeozoic cooling ages by a younger, mid-Cretaceous cooling event. Regionally, however, the boomerang trend diverges NNW away from the coast and crosses the escarpment, implying the underlying thermal history pre-dates escarpment formation and is largely independent from post-breakup landscape evolution. We suggest that Cretaceous cooling might relate to erosion of Permo-Triassic sedimentary cover from a formerly more extensive Sydney Basin.