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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

Aims: Debate over the optimal timing of oocyte denudation following oocyte retrieval continues. Multinucleation has been associated with lower embryo quality and implantation rate. Defining oocyte characteristics might increase the chances of better embryo selection. This study aimed to investigate the laboratory and clinical outcomes of intracytoplasmic sperm injection when the oocytes were denuded immediately after oocyte retrieval. Methods: A prospective randomized sibling-oocyte study was performed. The participants were under 40 years of age with more than 5 oocytes. Patients with male factors were excluded. The study and control groups were formed by simple randomization. The study group underwent oocyte denudation immediately. In the control group, oocytes were routinely incubated in an equilibration solution for 2 h until the removal of the cumulus cells. Outcome measures were normal fertilization (two pronuclei, 2PN), multinucleation rate, the proportion of good quality embryos, blastocyst formation, and pregnancy rate. Results: A total of 792 oocytes were collected from 54 participants (mean age: 30.6±3.7 years). The fertilization rate was higher in the study group (n=209 in 376) compared with the controls (n=201 in 416) (55.6% vs. 48.3%, p=0.041). The multinucleation rate (6.6% vs. 4.3%, p=0.150), proportion of grade 1 embryos on day 3 (48.7% vs. 43%, p=0.112) and day 5 (27.7% vs. 23.8%, p=0.214), the proportion of embryos reaching blastocyst stage (34.0% vs. 28.1%, p=0.072), and the pregnancy rates (78.6% vs. 71.4%, p=1.000) were similar. Conclusions: Our results demonstrated that immediate removal of cumulus cells does not have any negative impact on intracytoplasmic sperm injection outcomes.

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.

Cretaceous basins cover large parts of mainland SE Asia. Yet, the development during the Cretaceous is poorly understood including the establishment of the Cretaceous basin configuration. Based on detrital zircon and heavy mineral analysis, this study investigates the provenance of Lower Cretaceous deposits in the Phuquoc Basin, exposed in Cambodia and SW Vietnam and extending into the Gulf of Thailand. Our results document five major zircon populations with 130–145 Ma, 145–200 Ma, 200–270 Ma, 420–470 Ma, 1800–1900 Ma ages and two subordinate 2400–2700 Ma, 750–1000 Ma age clusters. These ages resemble those of the Qinling-Dabie and the Songpan-Ganzi orogenic belts and differ from other Asian terranes. These ages suggest that the Qinling-Dabie and Songpan-Ganzi orogenic belts were major sources of sediment for the Phuquoc Basin in the Early Cretaceous. Heavy mineral compositions including the presence of almandine, often co-occurring with silimanite and epidote, suggest metamorphic and granitic constituents in the hinterland, compatible with these orogenic belts being the source. The detrital zircon age pattern of the Phuquoc Basin closely resembles the zircon ages in Khorat and the Sichuan basins, suggesting a common sediment source, and bears great similarities with mid-Cretaceous strata in the Lanping-Simao Basin. These basins share a remarkable lithostratigraphic similarity and are confined by erosion. Taken altogether, this supports that the Phuquoc, Khorat, Sichuan, and probably the Lanping-Simao basins, formed part of a Cretaceous basin covering much of central SE Asia segregated by Late Cretaceous and Cenozoic denudation and translation. The absence of 130–145 Ma and 145–200 Ma aged zircons in the Lanping-Simao Basin suggests that another drainage system sprang from the Songpan-Ganzi Orogenic Belt and fed into this basin before merging with the Qinling-Dabie Orogenic Belt drainage system south of the Sichuan Basin. The combined drainage system likely passed through the Khorat Basin before entering the Phuquoc Basin.

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 mineral and chemical composition of bauxites from the Chadobets uplift of the Siberian Platform is the total product of laterites on aluminosilicate rocks (source of aluminum) and on alkaline rocks and carbonatites (source of rare earth elements (REEs), Nb, Ta, Th, U, etc.). The laterization of these rocks and subsequent denudation led to the formation of unique bauxite deposits with a high content of rare and REEs. Supergene minerals of the laterite weathering crust are in a dispersed microcrystalline and amorphous state, which complicates their study and the choice of methods for extracting useful components. Precision methods were used to establish the forms and compositions of the main supergene minerals, biomineral films, biomorphoses, and the distribution of rare and rare earth elements in them.

The Pliocene-Pleistocene transition resulted in extensive global cooling and glaciation, but isolating this climate signal within erosion and exhumation responses in tectonically active regimes can be difficult. The Nenana Gravel is a foreland basin deposit in the northern foothills of the Alaska Range (USA) that has long been linked to unroofing of the Alaska Range starting ca. 6 Ma. Using Al-26/Be-10 cosmogenic nuclide burial dating, we determined the timing of deposition of the Nenana Gravel and an overlying remnant of the first glacial advance into the northern foothills. Our results indicate that initial deposition of the Nenana Gravel occurred at the onset of the Pleistocene ca. 2.34 Ma and continued until at least ca. 1.7 Ma. The timing of initial deposition is correlative with expansion of the Cordilleran ice sheet, suggesting that the deposit formed due to increased glacial erosion in the Alaska Range. Abandonment of Nenana Gravel deposition occurred prior to the first glaciation extending into the northern foothills. This glaciation was hypothesized to have occurred ca. 1.5 Ma, but we found that it occurred ca. 0.39 Ma. A Pleistocene age for the Nenana Gravel and marine oxygen isotope stage 10 age for the oldest glaciation of the foothills necessitate reanalysis of incision and tectonic rates in the northern foothills of the Alaska Range, in addition to a shift in perspective on how these deposits fit into the climatic and tectonic history of the region. Geological Society of America Graduate Student Research Grant; Tulane University Lavin Bernick Faculty Grant Published version We thank Denny Capps, Mike Frothingham, Keir Nichols, and Chandler Powers for assistance with sample collection. We thank Adrian Bender, Julie Brigham-Grette, Mike Taylor and one anonymous reviewer for their thoughtful insight, which greatly improved the manuscript. Field work travel was funded in part by a Geological Society of America Graduate Student Research Grant. We thank the staff of PRIME Lab (Purdue University, Indiana, USA) for 10Be and 26Al analyses and the Louisiana State University Wetland Biogeochemistry Laboratory (Louisiana, USA) for inductively coupled plasma-optical emission spectrometry (ICP-OES) analyses. Additional support was provided by a Tulane University Lavin Bernick Faculty Grant to B. Goehring. Public domain – authored by a U.S. government employee

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.

[The analysis of the luminescence sensitivity of optically stimulated luminescence and thermoluminescence signals of sandstone samples from the Parnaiba Basin allowed to identify stratigraphic units and provided new insights about basin evolution. , Abstract Luminescence characteristics of quartz and feldspar allow to discriminate sediments from different source areas. Particularly, sensitivity of optically stimulated luminescence (OSL) and thermoluminescence (TL) signals of quartz and infrared‐stimulated luminescence (IRSL) of feldspar from Quaternary sediments has been used for provenance analysis. These properties change due to source area denudation rates and sediment reworking, which drive the number of burial irradiation‐solar exposure cycles of sediment grains in surface systems. Here, we use for the first time a similar approach to interpret the geomorphic conditions of source areas of Silurian to Triassic siliciclastic sedimentary units of the intracratonic Parnaiba Basin in northeast Brazil. Luminescence measurements were performed on sand grains, and statistical tests were applied to evaluate differences in luminescence properties within and across stratigraphic units. We explored the position of well‐known “110°C” (TL110) and “325°C” (TL325) TL peaks of quartz as proxies to discriminate stratigraphic units with similar lithological assemblages. OSL and TL sensitivities as well as the dominance of the so‐called fast OSL component increase from Silurian to Triassic sedimentary units, while the IRSL sensitivity decreases towards younger stratigraphic units. These patterns point to source areas with decreasing denudation rate and higher sediment recycling over basin filling time, leading to decreasing feldspar concentration and quartz luminescence sensitisation. Major changes in luminescence properties coincide with regional unconformities. This is attributed to physical landscape changes leading to shifts in the relief of source areas and basin sediment recycling. The TL110 peak position is similar across stratigraphic units, but the TL325 peak position has significant variation, with values between 324°C and 334°C, allowing its use for stratigraphic discrimination. Changes in OSL and TL characteristics of quartz sediment grains are preserved during long‐term burial (108 Ma), representing a new tool for interpreting basin evolution and to perform stratigraphic analysis of ancient siliciclastic successions.]

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.

Based on the analysis of the distribution of structural-material complexes, facial-genetic types and modeling of the history of immersion of the Lower Cretaceous sediments, the spatial-temporal differentiation of the tectonic regime of the Black Sea megadepression in the Early Cretaceous was established. It is shown that the structural and lithologicalfacial features of the Lower Cretaceous tectonic-sedimentation system were determined by the interaction of tectonic and geological-paleooceanographic factors. Thus, the low sea level and the initial phases of activation of sublatitudinal faults in the Hoterivian-Aptian determined the dominant influence of submeridional tectonic faults on the formation of the corresponding structural-facial block zonation. The increase in the area of the basin, the removal of denudation areas in the Late Albian reduced the intensity of terrigenous discharge, and the prolonged activity of sublatitudinal faults led to the formation of sublatitudinal structural-facial zonation. In the subsequent geological history, the tectonic regime was characterized by a complex mosaic-block character, which influenced the heterogeneity of oil and gas lithofluid systems of Cretaceous deposits.

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 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.

The coupling between chemical weathering (including silicate, carbonate and pyrite weathering) and physical erosion is of high interest in active mountain belts. Participation of pyrite weathering which, results in CO2 emission to the atmosphere, also is of great research attention. Nevertheless, the responses of the (de-)couplings to landslide and typhoon are unclear. We used records of riverine TDS (total dissolved solids) and TSS (total suspended solids) with high-frequency sampling during typhoons to estimate chemical denudation rates of silicate (CDRsil), carbonate (CDRcarb), pyrite (CDRpyrite) and physical denudation rates (PDR) in two adjacent catchments, eastern Taiwan. Results show that the CDRsil in the two catchments is approx. 10-fold higher than the global mean, whereas the CDRcarb, CDRpyrite and PDR are over 15-fold higher than the global averages. Landslides likely elevate carbonate and sulfate dissolution, and streamflow is a kinetic control on the CDRs. Among CDRs, CDRsil remains constant with various landslides and typhoons. Yet, CDRcarb and CDRpyrite rapidly respond to typhoons and then contribute more CO2 emission. In sum, landslides expose fresh minerals to enhance chemical weathering; typhoons, which transport the dissolved solids within a short time and prompt new rainwater for weathering, are also dominant agents. We demonstrate the importance of dynamic partitioning of sulfuric and carbonic acid on silicate weathering for quantitative estimation of weathering-associated CO2 budget in active mountain belts.

The Sao Francisco Craton (SFC) and its marginal Aracuai and Brasilia orogens exhibit a significant diversity in their lithospheric architecture. These orogens were shaped during the Neoproterozoic-Cambrian amalgamation of West Gondwana. The rigid cratonic lithosphere of the SFC and the relatively weak lithosphere of the Aracuai Orogen were disrupted during the Cretaceous opening of the South Atlantic Ocean, whereas the Brasilia Orogen remained in the continental hinterland. In earlier research, the thermal effects of the Phanerozoic reactivations in the shallow crust of the Aracuai Orogen have been revealed by low-temperature thermochronology, mainly by apatite fission track (AFT) analysis. However, analyses from the continental interior are scarce. Here we present new AFT data from forty-three samples from the Brasilia Orogen, the SFC and the Aracuai Orogen, far from the passive margin of the Atlantic coast (similar to 150 to 800 km). Three main periods of basement exhumation were identified: (i) Paleozoic, recorded both by samples from the SFC and Brasilia Orogen; (ii) Early Cretaceous to Cenomanian, recorded by samples from the Aracuai Orogen; and (iii) Late Cretaceous to Paleocene, inferred in samples from all domains. We compare the differential exhumation pattern of the different geotectonic provinces with their lithospheric strengths. We suggest that the SFC likely concentrated the Meso- Cenozoic reactivations in narrow weak zones while the Aracuai Orogen displayed a far-reachingMeso-Cenozoic deformation. The Brasilia Orogen seems to be an example of a stronger orogenic lithosphere, inhibiting reworking, confirmed by our new AFT data. Understanding the role of the lithosphere rigidity may be decisive to comprehend the processes of differential denudation and the tectonic-morphological evolution over Phanerozoic events. (C) 2021 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

The results of a geochemical, paleogeographic, and paleoclimatic study of a cyclically constructed section of upper Cretaceous deposits near Vol’sk city (Saratov oblast) are presented. Elementary layered cyclites and cyclic variations of several certain parameters were associated with the Milankovich astronomical-climatic cycles. Paleotemperature, humidity, and paleobathymetry curves were compiled. Paleotemperatures of the land surface in the denudation areas were obtained from the chemical index of alteration (CIA). Climatic cyclicity was established in the Turonian–Campanian interval, including a period of relative cooling (Turonian–Coniacian) with a paleotemperature of approximately 20°С, the period of relative warming in the mid–late Campanian (20–24°С), the cooling time at the end of the late Campanian (19–21°С) and the period of warming at the turn of the Campanian and Maastrichtian and in the early Maastrichtian time, there are two climatic cycles in Maastrichtian age, beginning with a time of relative cooling (approximately 19°С) and ending with a time of relative warming (approximately 20°С, at the end of Maastrichtian to 25°С). The cycles of climate humidity change are also determined: two cycles in Campanian time, three cycles in early Maastrichtian, and one cycle in late Maastrichtian. The boundary of the early and late Maastrichtian corresponds to the change of arid conditions to humid ones. The paleobatimetry curves show transgressive–regressive cycles: one in the late Turonian–Coniacian time, two in the late Campanian time, five in the early Maastrichtian time, and one in the late Maastrichtian time. Depth variations were estimated: in the Turonian–Coniacian time in the range of 70–80 m, in the Campanian–Maastrichtian time, the paleobatimetry consistently increased and changed from 100 to 200 m (on average approximately 150 m). These results provide an idea of the migration of the boundaries of the arid belt in the Late Creataceous and main features of the climatic zonation, which is important for regional and global paleoclimatic reconstructions, as well as for the history of the development the Russian Plate in the Ulyanovsk–Saratov region.

The higher rate of slope erosion in the Himalayan basins is contributing to rapid change in landform in the mountainous terrain, which has caused sedimentation, and inundation downstream. The Tamakoshi basin is a trans-boundary river that originates from Tibet and flows through Dolakha and Ramechap districts before joining the Sapta Koshi river. Few studies exist in Nepal attempting to quantify the erosion rate and susceptibility. However, they are scattered and mainly focus on either rill-sheet erosion or landslide only. Hence, this study attempted to estimate slope erosion by applying the Revised Universal Soil Loss Equation (RUSLE), and soil and debris erosion from landslide (2000-2019). Spatially distributed erosion intensity maps derived from the RUSLE model, as well as index-based landslide susceptibility map, were integrated to capture both running water and gravity erosion processes. The novelty of this research is that it examined the soil erosion rate using a process-based model as well as from the soil or rock displaced by the observed landslides over the last 20 years. The study estimated gross annual erosion by running water of 9.1million tons/yr, equivalent to the denudation rate of 3.34 mm/yr. Of these, landslide erosion accounts for 7.6 million ton/yr, i.e., 2.88 mm/yr, this covers about 84% of total slope erosion. High landslide and erosion potential areas are associated with high rainfall, steep slopes, scarps, lower segment of valley side slopes, high relief, and highly fractured and deformed parts of high-grade metamorphic rocks, such as gneiss, quartzite, marbles, migmatite, and granitic gneiss.

The Hong’an-Dabie-Sulu orogen in China exposes the largest area of ultrahigh-pressure (UHP) metamorphic rocks in the world. Postcollisional large-scale extension and denudation resulted in ...

Crooked Ridge and White Mesa in northeastern Arizona (southwestern United States) preserve, as inverted topography, a 57-km-long abandoned alluvial system near the present drainage divide between the Colorado, San Juan, and Little Colorado Rivers. The pathway of this paleoriver, flowing southwest toward eastern Grand Canyon, has led to provocative alternative models for its potential importance in carving Grand Canyon. The ∼50-m-thick White Mesa alluvium is the only datable record of this paleoriver system. We present new 40Ar/39Ar sanidine dating that confirms a ca. 2 Ma maximum depositional age for White Mesa alluvium, supported by a large mode (n = 42) of dates from 2.06 to 1.76 Ma. Older grain modes show abundant 37–23 Ma grains mostly derived ultimately from the San Juan Mountains, as is also documented by rare volcanic and basement pebbles in the White Mesa alluvium. A tuff with an age of 1.07 ± 0.05 Ma is inset below, and hence provides a younger age bracket for the White Mesa alluvium. Newly dated remnant deposits on Black Mesa contain similar 37–23 Ma grains and exotic pebbles, plus a large mode (n = 71) of 9.052 ± 0.003 Ma sanidine. These deposits could be part of the White Mesa alluvium without any Pleistocene grains, but new detrital sanidine data from the upper Bidahochi Formation near Ganado, Arizona, have similar maximum depositional ages of 11.0–6.1 Ma and show similar 40–20 Ma San Juan Mountains–derived sanidine. Thus, we tentatively interpret the

A boring billion for mountains Earth's crust has changed over time as supercontinents formed and broke apart. Tied into this cycle are the building and erosion of high mountains, which are tied to collisions between tectonic plates. Tang et al. use europium anomalies in zircons to estimate the mean thickness of crust over Earth's history. This proxy shows that mountain building has not always been as active as it is today or as it was very early in Earth's history. Mountain building, and the subsequent erosion, was less intense for about a billion years, roughly correlated with a so-called “boring billion” period of biological evolution. Science , this issue p. 728

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.

Carbonate hillslopes are often soil mantled and display a classic convex morphology. In this study we examine controls on carbonate hillslope denudation and morphology using a modified regolith mass balance equation to account for chemical weathering and dust input—two fluxes that are commonly neglected in settings with silicate-dominated bedrock. We utilize seven study sites in the Eastern Mediterranean across a significant gradient in the mean annual rainfall and dust deposition flux. Combining cosmogenic 36Cl-derived hilltop denudation rates with an estimate of the regolith chemical depletion and the quantified fraction of dust in the regolith we predict hilltop curvature and compare our predictions with observations based on high-resolution airborne LiDAR (light detection and ranging). Denudation rates vary from 5 to 210 mm/k.y. and increase with mean annual rainfall. Less resistant carbonates (chalk) experience faster denudation rates relative to more resistant dolo-limestone and are less prone to chemical weathering. Soil production exhibits a humped dependency on soil thickness. The observed hilltop curvature varies as a function of rainfall and dust flux with a minimum at sub-humid sites. While trends in hilltop convexity are often solely attributed to variations in erosion rate, our results illustrate the additional effects of dust production and chemical depletion. Our mass balance model implies that drier sites in the south probably experienced a more intricate history of regolith production due to dust flux fluctuations. Thus, by incorporating dust flux and chemical weathering to the classic hillslope evolution model we are able to identify a complex relation between hilltop curvature, soil production, and climate.

Riverine measurements of sediment and solute transport give empirical basin-scale estimates of bed-load, suspended-sediment, and silicate-solute fluxes for 100,000 km2 of northwestern California and western Oregon. This spatially explicit sediment budget shows the multifaceted control of geology and physiography on the rates and processes of fluvial denudation. Bed-load transport is greatest for steep basins, particularly in areas underlain by the accreted Klamath terrane. Bed-load flux commonly decreases downstream as clasts convert to suspended load by breakage and attrition, particularly for softer rock types. Suspended load correlates strongly with lithology, basin slope, precipitation, and wildfire disturbance. It is highest in steep regions of soft rocks, and our estimates suggest that much of the suspended load is derived from bed-load comminution. Dissolution, measured by basin-scale silicate-solute yield, constitutes a third of regional landscape denudation. Solute yield correlates with precipitation and is proportionally greatest in low-gradient and wet basins and for high parts of the Cascade Range, where undissected Quaternary volcanic rocks soak in 2–3 m of annual precipitation. Combined, these estimates provide basin-scale erosion rates ranging from ∼50 t · km−2 · yr−1 (approximately equivalent to 0.02 mm · yr−1) for low-gradient basins such as the Willamette River to ~500 t · km−2 · yr−1 (∼0.2 mm · yr−1) for steep coastal drainages. The denudation rates determined here from modern measurements are less than those estimated by longer-term geologic assessments, suggesting episodic disturbances such as fire, flood, seismic shaking, and climate change significantly add to long-term landscape denudation.

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.

Thermochronological methods were applied to the Higher Himalayan Crystalline (HHC) nappe and the underlying Lesser Himalayan Sequences (LHS) to elucidate the denudation process for the middle- and upper-crust of eastern Nepal over millions of years. Thermochronological inverse modeling was undertaken for new results of fission-track (FT) age and FT length data of zircon and apatite in order to reconstruct the time-temperature (t-T) paths in the temperature range of 60–350°C. Eight t-T paths calculated along the across-strike section show that the cooling process of the HHC nappe in this study area is characterized by the following three aspects: (a) gradual cooling followed by rapid cooling and subsequent gradual cooling, (b) northward-younging of the timing of the rapid cooling, and (c) gradual cooling followed by

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 most crucial problem of placer geology is the determination of its root source. Despite the large number of works dedicated to the study of amber placers formed in the territory from the Baltic coast to the Black and Azov Seas, so far, no native source has been established. Therefore, this article aims to establish the genetic type of the source of ambersuccinite placers formed under optimal climatic conditions of the first half of the Middle Eocene (Buchak time, Lutetian) on the territory of the low plains of the Ukrainian Shield surrounded by shallow sea basins. The article discusses a set of factors that contributed to forming the source of amber-succinites and forming its placers within the Ukrainian Shield and its slopes, covering the bordering areas of the Pripyat Trough, the Dnieper-Donetsk and the Black Sea depressions, and the Volyn-Podilsk Plate.For the first time, the authors have established that the primary source of amber-succinite placers is not the generally recognized “amber-bearing” pines of Scandinavia. Instead, it is the primary biogenic-sedimentary deposits of tar secretions (according to the authors — proto-amber, resin bodies at the early stage of fossilization) mainly of coniferous trees. These secretions were fossilized in the humidified forest bedding of the Buchak time in the lower half of the Middle Eocene. Only as a result of erosion of these biogenic-sedimentary deposits by river waters and other agents of denudation, proto-amber was transported in the post-Buchak time to various areas of sedimentation, where the formation of various mineral species of fossil resins took place. Amber-succinite was not found in the marine sediments of Buchak time, that indicates immaturity of the proto-amber for conversion into succinite at that time.On the territory of Ukraine only in the sea paleo-basin, which surrounded the Ukrainian Shield from the north, east, and south-west, the proto-amber acquired all the features and properties of amber-succinites at the end of the MiddleUpper Eocene — Early Oligocene. Thus, it is the paleo peat bogs of the Lower Middle Eocene that contain the protoamber (resin bodies at the early stage of fossilization) that are the root source of amber-succinite placers.Based on the comprehensive geological and palaeogeographical analysis of the region’s natural conditions in the Eocene—Oligocene, when the tar bodies accumulated in this area and transformed into fossil resins, the authors identified the main stages of tar resin fossilization during the long transition from the biosphere to the lithosphere. These are three transformation stages: terrestrial, marine, and post-diagenetic. Secondary placers of amber-succinites have accumulated in the coastal, estuarine, and remote parts of the sea shelf. They are covered by sediments from the Kyiv, Obukhiv, and Mezhyhirya regional stages formed at the end of the Oligocene when primary biogenic-sedimentary deposits were eroded.

The Qinling Orogenic Belt in Central China is formed by an oblique continental collision between the North China and South China Blocks. In this review, we summarize the knowledge of the early Mesozoic magmatism, in combination with the coeval metamorphic characteristics, regional structural features and depositional history in the foreland and hinterland basins along the Qinling-Dabie Orogen. The early Mesozoic tectonic evolution of the Qinling is divided into four stages. Stage I (~250–235 Ma) is characterized by medium-K calc-alkaline magmatism in the western Qinling induced by slab roll-back. Meanwhile, ultrahigh-pressure metamorphism was triggered by continental subduction in the Sulu-Dabie, indicating a diachronous closure of the ocean. Stage II (~235–225 Ma) is recognized as a magmatic gap. Depositional variations of sedimentary facies and compressional deformations with an increased crustal thickness reflect the initial collision in the Qinling. Stage III (~225–210 Ma) is distinguished by a magmatic flare-up event. Abundant mantle-derived melts coupled with extensive crustal-derived melts were coeval with rapid uplift, strike-slip movement and regional crustal thickening in the Qinling as well as retrograde metamorphism in the Sulu-Dabie. The main tectonic driver was the propagating detachment of the subducted oceanic slab at gradually shallower depth from the Sulu-Dabie to the Qinling. Stage IV (~210–190 Ma) magmatism is dominated by high silica granites derived from metasedimentary rocks. The rapid denudation rates and extensional structures indicate gravitational collapse and regional delamination of the thickened crust. In addition to the strike-slip faults and block extrusion, the Qinling is characterized by asymmetric distribution patterns of magmatism and metamorphism, different melting mechanisms over time; diachronous depositions, differential uplift and non-uniform crustal thickening, and regional delamination of the thickened orogenic root. All these features are the result of the oblique collision, which is a common process in nature, and therefore could be applied to other orogens.

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

International audience; To better constrain late Neogene denudation of the Himalayas, we analysed in situ 10Be concentrations in 17 Neogene sediment samples of the Surai section (central Nepal) and two modern sediment samples of the Rapti River. We first refined the depositional ages of the Surai section from 36 new paleomagnetic analyses, five 26Al/10Be burial ages, and, based on the Dynamic Time Warping algorithm, 104 automatically calculated likely magnetostratigraphic correlations. We also traced changing sediment sources using major element and Sr‐Nd isotopic data, finding at 4–3 Ma a switch from a large, trans‐Himalayan river to a river draining only the Lesser Himalaya and Siwalik piedmont, increasing the contribution of recycled sediments at that time. 10Be concentrations in Neogene sediments range from (1.00 ± 0.36) to (5.22 ± 0.98) × 103 at g–1 and decrease with stratigraphic age. Based on a flood plain transport model, our refined age model, and assuming a drainage change at 4–3 Ma, we reconstructed 10Be concentrations at the time of deposition. Assuming cosmogenic production rates similar to those of the modern basins, we calculated palaeodenudation rates of 0.9 ± 0.5 to 3.9 ± 2.7 mm a–1 from ca. 6 to 3 Ma in the palaeo‐Karnali basin and 0.6 ± 0.2 to 1.6 ± 0.8 mm a–1 since ca. 3 Ma in the palaeo‐Rapti basin. Given the uncertainties and similar modern values of ~2 mm a–1, the palaeo‐Karnali denudation rates may have been steady at ~1.7 ± 0.3 mm a–1 for the last ca. 6 Ma. A transient acceleration of the denudation in the palaeo‐Rapti basin of ~1.5 mm a–1 since ca. 1.5 Ma was likely due to the reworking of older, 10Be‐depleted Siwalik sediments in the foreland. If true, this steadiness of the denudation rates may suggest that Quaternary glaciations did not largely affect Himalayan denudation.

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.

The stratigraphic record of Cenozoic uplift and denudation of the Himalayas is distributed across its peripheral foreland basins, as well as in the sediments of the Ganges–Brahmaputra Delta (GBD) and the Bengal–Nicobar Fan (BNF). Recent interrogation of Miocene–Quaternary sediments of the GBD and BNF advance our knowledge of Himalayan sediment dispersal and its relationship to regional tectonics and climate, but these studies are limited to IODP boreholes from the BNF (IODP 354 and 362, 2015-16) and Quaternary sediment cores from the GBD (NSF-PIRE: Life on a tectonically active delta, 2010-18). We examine a complementary yet understudied stratigraphic record of the Miocene–Pliocene ancestral Brahmaputra Delta in outcrops of the Indo-Burman Ranges fold–thrust belt (IBR) of eastern India. We present detailed lithofacies assemblages of Neogene delta plain (Tipam Group) and intertidal to upper-shelf (Surma Group) deposits of the IBR based on two ∼ 500 m stratigraphic sections. New detrital-apatite fission-track (dAFT) and (U-Th)/He (dAHe) dates from the Surma Group in the IBR help to constrain maximum depositional ages (MDA), thermal histories, and sediment accumulation rates. Three fluvial facies (F1–F3) and four shallow marine to intertidal facies (M1–M4) are delineated based on analog depositional environments of the Holocene–modern GBD. Unreset dAFT and dAHe ages constrain MDA to ∼ 9–11 Ma for the Surma Group, which is bracketed by intensification of turbidite deposition on the eastern BNF (∼ 13.5–6.8 Ma). Two dAHe samples yielded younger (∼ 3 Ma) reset ages that we interpret to record cooling from denudation following burial resetting due to a thicker (∼ 2.2–3.2 km) accumulation of sediments near the depocenter. Thermal modeling of the dAFT and dAHe results using QTQt and HeFTy suggest that late Miocene marginal marine sediment accumulation rates may have ranged from ∼ 0.9 to 1.1 mm/yr near the center of the paleodelta. Thermal modeling results imply postdepositional cooling beginning at ∼ 8–6.5 Ma, interpreted to record onset of exhumation associated with the advancing IBR fold belt. The timing of post-burial exhumation of the IBR strata is consistent with previously published constraints for the avulsion of the paleo-Brahmaputra to the west and a westward shift of turbidite deposition on the BNF that started at ∼ 6.8 Ma. Our results contextualize tectonic controls on basin history, creating a pathway for future investigations into autogenic and climatic drivers of behavior of fluvial systems that can be extracted from the stratigraphic record.

To understand the physical mechanisms of the spattering and denudation phenomena in the laser powder bed fusion process, we develop a multiphase flow model by bi-directionally coupling the discrete element method and finite volume method, where the exchanges of both momentum and energy between the powder particles and gases are incorporated. It is the first time that the dynamic behaviours of both the gas phase and powder particles during the spattering and denudation phenomena are reproduced in computational modelling, which agree well with the published experimental observation. The metal vapour spouts out and decelerates sharply along the jetting direction while expanding radially, which induces remarkable vortex flows of the ambient gas. With comparative simulation cases, the vapour jetting and the consequent vortex flow are demonstrated to be dominant in the spattering and denudation phenomena, and the thermal buoyancy effect is proved to be negligible. Moreover, the influence of the jetting angle is investigated: no remarkable effect within the range of 60° - 120°; while larger than 150°, the accumulation zone is eliminated leading to a completely exposed denudation zone.

Large-scale gas accumulation areas in large oil-gas basins in central and Western China have multiple special accumulation mechanisms and different accumulation effects. Based on the geological theory and method of natural gas reservoir formation, this study examined the regional geological and structural background, formation burial evolution, basic characteristics of gas reservoirs, and fluid geology and geochemistry of typical petroliferous basins. The results show that the geological processes such as structural pumping, mudstone water absorption, water-soluble gas degasification and fluid sequestration caused by uplift and denudation since Himalayan stage all can form large-scale gas accumulation and different geological effects of gas accumulation. For example, the large-scale structural pumping effect and fluid sequestration effect are conducive to the occurrence of regional ultra-high pressure fluid and the formation of large-scale ultra-high pressure gas field; mudstone water absorption effect in the formation with low thickness ratio of sandstone to formation is conducive to the development of regional low-pressure and water free gas reservoir; the water-soluble gas degasification effect in large-scale thick sandstone can not only form large-scale natural gas accumulation; moreover, the degasification of water-soluble gas produced by the lateral migration of formation water will produce regional and regular isotopic fractionation effect of natural gas, that is, the farther the migration distance of water-soluble gas is, the heavier the carbon isotopic composition of methane formed by the accumulation.

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.

[Abstract The influence of climate on mountain denudation has been the topic of an intense debate for two decades. This debate partly arises from the covariation of rainfall and topography during the growth of mountain ranges, both of which influence denudation. However, the denudational response of this co‐evolution is poorly understood. Here, we use a landscape evolution model where the rainfall evolves according to a prescribed rainfall–elevation relationship. This relationship is a bell curve defined by a rainfall base level, a rainfall maximum and a width around the rainfall peak elevation. This is a first‐order model that fits a large range of orographic rainfall data at the ca. 1‐km spatial scale. We carried out simulations of an uplifting block with an alluvial apron, starting from an initially horizontal surface, and testing different rainfall–elevation relationships. We find that the denudation history is different from that with constant rainfall models. The results essentially depend on the ratio between the final steady‐state summit elevation Hss and the prescribed rainfall peak elevation Hp. This ratio is hard to predict because it depends on the transient coupling of rainfall and elevation. We identified three types of results according to Hss/Hp. If Hss/Hp > 4 (Type I), the denudation rates peak when the summits reach values close to Hp. If Hss/Hp > 1.5 and < 4 (Type II), the denudation is strongly accelerated when the elevation of the summits approaches Hp, and then the denudation increases slowly towards the uplift rate. If Hss/Hp < 1.5 (Type III), the denudation evolution is similar to situations with constant and homogeneous rainfall. In the Type I and II experiments, the mountain top is subjected to aridification once the summits have passed through Hp. To adapt to this reduced rainfall, the slopes increase. This can lead to a paradoxical situation where the mountain relief increases faster, whereas the denudation increases more slowly. The development of orographic precipitation may thus favour the stability of the mean denudation rate in a rising mountain. Despite the model limitations, including a constant rainfall–elevation relationship, our study suggests that the “classical” exponential increase in the denudation rate predicted by constant rainfall models is not the common case. Instead, the common case involves pulses and acceleration of the denudation even in the absence of uplift or global climate variations., The development of a precipitation peak at some elevation within mountain catchments appears to be a crucial factor that controls the denudation and topographic evolutions of a mountain. If the precipitation peak is located at low or medium elevation when the mountain has reached a dynamic equilibrium, the model predicts that denudation has strongly accelerated (b) in the early times of the mountain uplift, or even passed by a maximum resulting in a pulse of sediment outflux to basins (a). If the precipitation rate does not have a maximum in the mountain, it can be deduced that the denudation has not evolved differently from cases where the precipitation rate is constant (c). These results can be used to re‐examine the interpretation of sediment flux variations in real cases based on the current distribution of precipitation rates with altitude in mountain ranges. ]