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Studying taphonomy is crucial for understanding how post-depositional processes impact archaeological remains. This knowledge is pivotal for accurately interpreting the archaeological record. Although taphonomy has a long tradition in archaeology, it is less developed in the analysis of stone tool residues compared to other subdisciplines. To address this gap, our study aims to further develop our understanding of the preservation potential of stone tool residues in temperate environments through actualist experiments. To achieve this, we develop a multidimensional experimental program that features the first biweekly monitoring of weathering processes on residues over a one-year cycle, aiming to understand the short-term effects of weathering immediately after tool discard. Additionally, the program involves the study of longer-term burial and weathering visual effects on different residue types within various previously unexplored depositional environments. This approach allows us to observe the visual effects of both weathering and burial processes and to improve our understanding of the different mechanisms involved in the diagenesis of stone tool residues. While known factors such as microbial activity and soil acidity play a primary role in residue decay, specific stone tool-related factors also prove important, underscoring the need to develop further a specific branch of taphonomy related to stone tool residues. Moreover, our results show that certain residue types may survive within these environments that are often considered as being hostile. A residue analysis of stone tools from temperate contexts may thus contribute unique data that can improve our understanding of past human behaviour. Future research with more diverse residue types and depositional conditions will permit further refinement of our understanding of how taphonomy affects residue preservation and enhance the reliability of residue identifications. As such, stone tool residue analysis will become firmly rooted within broader functional approaches to address how humans use stone tools and how this affects stone tool variability. [ABSTRACT FROM AUTHOR]

Studying the effects of weathering on the mechanical properties and microscopic evolution of weathered granite soil (WGS) is essential for connecting microstructure with macroscopic behavior. This study conducts systematic monotonic and cyclic triaxial tests, along with a series of microscopic tests on WGS samples, to explore the influence of weathering on WGS mechanical properties and the mechanism of granite weathering. Results indicate that both effective internal friction angle and effective cohesion decrease progressively with increased weathering. Completely weathered granite (CWG) exhibits greater dynamic strength compared to granite residual soil (GRS). Additionally, as weathering progresses, quartz fragments are lost, while feldspar and biotite weather to form secondary minerals such as kaolinite and illite, leading to an overall enrichment in aluminum and iron in the granite. Weathering causes structural deterioration of WGS. Finally, the mechanical parameters of WGS and their chemical weathering indices show a coefficient of determination ranging from 60 to 99%. This study helps elucidate the fundamental causes of performance changes in WGS, thereby optimizing engineering design and enhancing disaster prediction accuracy, while providing new research perspectives and experimental evidence for WGS. [ABSTRACT FROM AUTHOR]

The mixed Fe(II)/Fe(III) mineral magnetite [Fe3O4] of various stoichiometric and non‐stoichiometric compositions have been reported in Martian soils and rocks by several rover missions. Magnetite is an important paleomagnetic indicator mineral and can serve as a 'biogeobattery' as a consequence of its magnetic properties and the mixed valence state of iron in its structure. Here, we assess the extent of oxidative weathering of magnetite in presence of chlorate and bromate containing solutions that are likely important oxidants on Mars. Oxyhalogen species, chlorate and bromate, produced non‐stoichiometric magnetite [Fe(II)/Fe(III) < 0.5] in Mars‐relevant, near‐neutral pH fluids; no other ferric minerals were produced. The same results were observed in highly acidic fluids with or without oxyhalogens. Owing to its resistance to extensive oxidation, magnetite can serve as an important archive of geochemical, paleomagnetic, and astrobiological information in samples that will be returned by the Mars Sample Return mission. Plain Language Summary: Magnetite is an iron oxide that contains both Fe(II) and Fe(III) in its crystal structure. The Fe(II) to Fe(III) ratio in an ideal (i.e., stoichiometric) magnetite is 0.5, that decreases as Fe(II) in its structure oxidizes to Fe(III) thereby forming non‐ideal (i.e., non‐stoichiometric) magnetite. Owing to its unique structure, magnetite can serve as an important paleomagnetic indicator mineral and a source of energy for microorganisms. Therefore, understanding the survivability of magnetite in presence of the harsh oxidizing chemical environment on Mars is important. Here, we conduct laboratory experiments in Mars‐like fluids to test the reactivity of magnetite in presence of strong and effective oxidants that have previously been shown to be active on Mars. Our results show that magnetite is resistant to extensive oxidation in presence of chlorate and bromate solutions to an extent that is much greater than other Fe(II) minerals like iron sulfides, and forms non‐stoichiometric magnetite making it a useful target for analyses of samples from the Mars Sample Return mission aimed at understanding Mars' magnetic history and habitability. Key Points: Magnetite shows resistance to oxidation by oxyhalogen compounds (chlorate and bromate) in Mars‐relevant fluidsNon‐stoichiometric magnetite on Mars may be formed by aqueous alteration of stoichiometric magnetite by oxyhalogen compoundsMagnetite likely preserves geochemical, paleomagnetic and astrobiological information and is an important target mineral in Mars return samples [ABSTRACT FROM AUTHOR]

A linear relationship between rates of physical erosion and chemical weathering is apparent in slowly eroding landscapes. Whether the relationship remains linear in rapidly eroding landscapes is less clear. Field‐based research into this relationship between erosion and weathering rates has largely been conducted in temperate climates with granitic bedrock. In tropical settings, the contribution of chemical mass loss to total denudation may approach, or even exceed, that of erosion. We report 10Be‐in‐quartz cosmogenic radionuclide and soil chemistry data from the Suckling‐Dayman Metamorphic Core Complex (SDMCC) in Papua New Guinea. Despite being exhumed at cm‐per‐year rates, its lower‐plate domed and striated morphology suggests minimal denudation, which is confirmed by our 10Be‐in‐quartz data (0.02–0.18 mm/yr). We suggest that rolling hinge‐style back‐rotation of the SDMCC's lower plate and the combination of a tropical climate and highly weatherable metabasalt bedrock have played a fundamental role in preserving the tectonic topography of this remarkable metamorphic core complex. Plain Language Summary: Where mountains are raised (uplifted) slowly by plate tectonics, erosion (the removal of rocks/soils) tends to be slow. Where erosion is slow, chemical weathering (the local breaking down or dissolving of rocks/minerals) is usually slow as well. This observation has been made in mountainous regions around the world with temperate climates, and where mountains consist predominantly of granitic rocks. However, much less is known about how rates of erosion and weathering relate in tropical climates where mountains rise rapidly. We studied a unique geological structure in tropical Papua New Guinea (the Suckling‐Dayman Metamorphic Core Complex, SDMCC) to provide new data for addressing this knowledge gap. We measured denudation rates (the sum of physical and chemical mass loss) using a method that is based on the accumulation of atomic particles that form in the crystal lattice of minerals in rocks and soils by cosmic rays. Our denudation rates are much slower than the rate at which the SDMCC is being raised by tectonic processes, requiring some erosion‐limiting mechanism(s). The chemical compositions of basaltic soils from the SDMCC, however, imply intense weathering. We argue that the style of tectonic uplift and the tropical weathering regime are responsible for the slow denudation rates. Key Points: 10Be‐in‐quartz denudation rates of the rapidly uplifting Suckling‐Dayman Metamorphic Core Complex are in the range of 0.02–0.18 mm/yrRapid, intense weathering of its metabasaltic footwall bedrock is implied by mobile and immobile weathering indices in soil samplesThe pristine topography of Mount Dayman is strongly influenced by rolling hinge‐style tectonics and the tropical weathering regime [ABSTRACT FROM AUTHOR]

Developing high-performance mid and far infrared antireflection films is a significant requirement in the field of infrared optics. This study successfully prepared AR films composed of ZnS nanospheres for mid and far infrared bands using a combination of hydrothermal and sol-gel methods. Initially, ZnS nanospheres with uniform size and good monodispersity were synthesized via the hydrothermal method and subsequently coated on CdSe substrate through dip coating. The refractive index of the ZnS film is adjusted between 1.36 and 1.52. A significant AR effect was observed in ZnS nanospheres film on CdSe substrate at 3–5 μm and 8–14 μm, and the reflectance is approximately 3 % which is about 25 % lower than that of the uncoated sample. Upon coating with a TiO 2 protective layer, the reflectivity further decreased to about 0.6 % and the film demonstrated excellent weather resistance and mechanical properties. This work provides a novel approach for the preparation and regulation of mid and far infrared AR film, significantly contributing to the development of optical film. [ABSTRACT FROM AUTHOR]

The research deals with the study of geomorphological phenomena of the drainage basin area of Wadi al-Qelt located between latitudes E°31 '55 "59 and °31 '48 "27 north, and longitudes N °35 '12 "22 and °35 '32 "51 east, and is one of the valleys of the eastern slopes of: the mountains of Ram Allah and Jerusalem, located within the mountain range of central Palestine, and ends in the Jordan Valley in the east of Jericho at the Jordan River coupler, It aims to vary the influence of geomorphological factors in the formation of terrain features, as the geological structure, both rock and tectonic, had the largest role in the geomorphological formation of the region, where doloms and soluble limestone rocks are spread, which resulted in the presence of karst forms, and marlin rocks that can be carved and eroded, which resulted in the active decline of slopes and the intensification of the number of river ranks. The second part of the structure, represented by the tectonic factor, resulted in its impact on the Afro-Asian groove (collapse pit), the direction and intensity of the general slope and the resulting increase in the energy of the valleys on vertical sculpture, deepening and formation of gorges and others, while the second factor represented by the ancient and current climate has clearly appeared its effects in the parts of the drainage basin, where the effects of the current climate appeared by the extreme variation of rain amounts between the parts of the study area, and the impact of the ancient climate was manifested in the lower basin Which was greatly affected by the change in the levels of the ancestor of the Dead Sea, which were alternating those parts, the study followed the descriptive, historical, and analytical approach to describe the geographical reality and its characteristics, trace geological eras, and employ (GIS) technology. It concluded that the basin consists of a set of structural geomorphological phenomena, phenomena resulting from erosion and sedimentation, and phenomena associated with weathering processes, and the study recommended carrying out many geomorphological studies on the region and identifying what abounds in the geography of the Wadi basin Clumping is a morphodynamic, morphodynamic process. [ABSTRACT FROM AUTHOR]

Clouds play a pivotal role in determining Earth’s climate, impacting several atmospheric processes influencing the weather. The study explores the temporal variations in cloud base height (CBH) over Pune, a tropical station, from 2017 to 2023 using a Laser-Based Ceilometer with a range of 0–7500 m. Our analysis shows seasonal trends in CBH, with the monsoon season exhibiting unique characteristics showing the lowest average CBH and minimal diurnal changes during the study period. Conversely, the pre-monsoon, post-monsoon, and winter season show a gradual rise of CBH in the morning, maintaining higher levels until late afternoon, followed by a decline in the evening. Analysis of the diurnal frequency of cloud occurrence at 500 m intervals reveals the monsoon season’s dominance in the 500 m to 1000 m layer. Throughout the year, low cloud bases (CBH <2000 m) are most frequent, outpacing the frequency of mid and high cloud bases. High cloud base (7500 < CBH > 6000 m) is the least common, showing a semi-diurnal pattern in winter with peaks around noon and midnight. These findings not only enhance our understanding of Pune’s atmospheric behaviour but also offer valuable information for weather prediction, climate modelling, and environmental monitoring. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the effect of combined end-and-side grouting on the bearing properties of large-diameter rock-socketed bored piles in highly weathered rock layers. Eight full-scale pile load tests were conducted in the highly weathered rock layer to analyze the enhanced mechanism of the combined grouted bored piles. The test data from pile mechanical testing were compared with the recommended values in the current specification and geological survey report. The results demonstrate significant improvement in the side and end resistances of the combined grouted bored piles, resulting in a substantial increase in the bearing capacity and effective settlement control. It was observed that the construction of impact holes for bored piles can cause severe damage to highly weathered rock structures and weaken the mobilization of side and end resistances. Moreover, it was found that the calculation of the enhancement coefficient in the current specification underestimates the practical bearing capacity. The measured enhancement coefficients for the side and end resistance of piles in fully or highly weathered rock layers range from 2.49 to 3.05 and 2.24 to 2.43, respectively, which are more reasonable and feasible for the calculation. The research findings deepen the understanding of the bearing characteristics of large-diameter rock-socketed bored piles with combined grouting and provide valuable case references for the optimal design of large-diameter combined grouted piles for building foundations in Shenzhen, China. Highlights: Post-grouting had the potential to improve super high-building foundation reliability while reducing pile length and cost. The improvement effect and improvement mechanism of combined grouted bored piles embedded in highly rock strata were revealed. The influence of the size effect for large-diameter piles in highly weathered rock was revealed. The construction of impact holes for bored piles can cause severe damage to highly weathered rock structures and weaken the mobilization of side and end resistances. The enhancement coefficients for the side and end resistance of piles in fully or highly weathered rock layers were proposed. [ABSTRACT FROM AUTHOR]

Illitization of smectite in sedimentary systems, a process akin to "reverse weathering," is a diagenetic process that has significant implications for sediment paragenesis and hydrocarbon exploration. However, the potential influence of chemical weathering on the illitization of smectite and its possible control of the neogenesis of titanium (Ti)-oxides remain unclear. Altered volcanic tephra layers (i.e., K-bentonites) characterized by an interstratified illite-smectite (I-S) clay mineralogy serve as an excellent medium to investigate the illitization of smectite. In this study, we first investigated the fine structure of clay minerals and in situ nano-mineralogy of Ti-bearing minerals from altered volcanic ashes and then undertook a meta-analysis of geochemical compositional data for bentonites spanning a wide range of ages and depositional environments globally. We found that Ti mainly occurs as discrete micrometer-scale magmatic srilankite and nanoscale authigenic anatase crystals. During the weathering process, the magmatic srilankite partly dissolved under acidic conditions, resulting in a local buildup of Ti in porewaters. The I-S displays a platy habit and curved edges and is found closely associated with anatase crystals under TEM. Our compilation results combined with microscopic evidence suggest that chemical weathering may potentially promote the illitization reaction by changing the chemical composition of the fluids through increased terrestrial inputs and by creating larger pore spaces through the decomposition of weatherable components. Positive correlations between K and Ti are especially common in (K-)bentonites that are dominated by I-S, suggesting that I-S can adsorb Ti during the weathering process and provide a suitable site for the nucleation of anatase. Our study highlights the role of chemical weathering in the illitization of smectite and their combined effect on the formation of Ti-oxides. [ABSTRACT FROM AUTHOR]

It is necessary to analyze the characteristics of the water environment and factors influencing the basin in order to determine its current ecological status. This study aims to investigate the chemical properties in the Shichuan River Basin using Gibbs diagram, Piper triangle diagram, correlation analysis, factor analysis, and main ion ratio method. The enhanced Nemerow comprehensive index method and fuzzy comprehensive evaluation method are employed for river water quality assessment. The findings reveal that runoff water has a weak alkaline nature with low salinity. The hydrochemical type of river water includes Ca2++Mg2++Na+-SO42-, Ca2++Mg2+-SO42-+Cl-+HCO3-, Ca2++Na+-SO42-+Cl-+HCO3-. Silicite and dolomite weathering are identified as primary influencing factors, while evaporite weathering also contributes to variations in chemical composition within the basin's waters. Ca2+, Mg2+, SO42- and HCO3- originate from carbonate rock and silicate rock weathering processes, whereas Na+, K+ and Cl-, are primarily derived from evaporite weathering influenced by domestic sewage and agricultural activities. Agricultural production practices along with discharge of domestic sewage have an impact on Na+, K+, Cl- and NO3-concentrations in aquatic systems. Water quality at all three monitoring sections falls under level IV classification. Phosphorus emerges as a key limiting factor for eutrophication within this basin's watersheds. [ABSTRACT FROM AUTHOR]

The Araba and Naqus formations in Ras Milan, Sinai, constitute part of the major continuous Paleozoic clastic belt stretching across northern Gondwana. They are sandstone-dominated successions, resting on Precambrian granitic basement, with lowermost thin basal polymictic conglomerate deposits (1–2 m), marking the unconformity. The Araba Formation section is composed mainly of varicoloured violet to reddish brown, fine to coarse-grained laminated and planner and overturned cross-bedded sandstones, while the overlying Naqus Formation is characterized by chaotically distributed poorly sorted quartz pebbles to cobbles within a moderately-sorted coarse- to medium-grained quartz arenite and by abundance and variety of large-scale tabular and trough cross bedding. Modal QFL classification of Araba and Naqus formation sandstones revealed that they are merely quartzose sandstones (quartz arenites). Geochemistry of the succession shows extremely wide compositional ranges for almost all major elements, but the Araba Formation is relatively enriched in SiO2, TiO2, Fe2O3*, Na2O, P2O5, and depleted in Al2O3, MgO, CaO and K2O relative to Naqus Formation. Only the Araba Formation samples are depleted in the transition elements Ni, Cr and Co and oppositely possess extreme enrichment in the HFSEs (i.e. Zr, Hf, Y, Nb, Ta, Th, U), whereas both formations show variable depletion in the LILE Rb, K and Ba, and excessive REE abundances relative to the PAAS and UCC, and LREE-enriched patterns with marked negative Eu anomalies. The provenance of the Naqus and Araba formations could be an earlier felsic magmatic source, which has undergone extensive sedimentary recycling. They possess high compositional maturity and were subjected to intensive to moderate weathering during humid climatic conditions. Passive margin tectonic setting is implied which denotes the derivation of Araba and Naqus formation siliciclastics from stable continental regions or plate interiors and deposition in intracratonic basins. [ABSTRACT FROM AUTHOR]

The current study focuses on the degradation rate of polypropylene (PP) and Bauhinia Vahlii (BV) fibers under soil burial and natural weathering conditions for 360 days. The BV‐PP composite was produced with varying BV fiber compositions (0, 10, 20, and 30 wt.%) and 3 % MAPP (Maleic Anhydride Grafted Polypropylene). In addition, MAPP is employed as a coupling agent to improve fiber‐matrix compatibility and promote degradation. The XRD examination shows that a 10 % BV‐PP composite has a crystallinity index of 52.05 %, which is higher than that of neat PP. The rate of biodegradability was investigated using weight loss and tensile properties. The largest degradation was seen in natural weathering conditions with 30 % composite showing the maximum weight loss of 3.8 % and loss in tensile strength and modulus of 16.76 % and 5.11 %, respectively. Simultaneously, no weight loss or drop in tensile characteristics was found in the case of neat PP over 360 days. The SEM images of soil burial show material deterioration, which may be aided by bacterial and fungal activity, whereas natural weathering conditions show a large crack, rougher fracture surface, and cavities, which are attributed to thermal stresses, changes in moisture content, and ultraviolet radiation, thereby promoting the degradation process. [ABSTRACT FROM AUTHOR]

Five decades of monitoring data (1974–2022) at the acidified forested catchment of Langtjern in southern Norway document strong chemical recovery and browning of surface water, related to changes in sulfur (S) deposition. Further recovery is likely to be impacted by future air quality and climate, through catchment processes sensitive to climate change, where the relative importance of these drivers of recovery is poorly known. Here, we explore the importance of the aforementioned drivers for recovery using the well‐established process‐oriented Model of Acidification of Groundwater In Catchments (MAGIC) with historical and projected deposition and climate from 1860 to 2100. New in MAGIC are (i) a solubility control of dissolved organic carbon (DOC) from S deposition, which allows inclusion of the role of organic acids in chemical recovery and (ii) climate‐dependency of weathering rates. MAGIC successfully described observed chemical recovery and browning, and the change toward organic acid dominated acidification status. Hindcasts of pH predicted lower preindustrial pH than previously modeled with MAGIC (simulated without S‐dependency of DOC solubility). Future deposition resulted in limited further recovery. Climate scenarios indicated a substantially wetter future, leading to increased base cation losses and slight surface water reacidification. A sensitivity analysis revealed that a 25%–50% increase of weathering rates was needed to reach preindustrial acid‐neutralizing capacity in 2100, provided S deposition is reduced to a minimum. We predict that the limited chemical recovery from reduced S deposition will be counteracted by climate‐driven reacidification from base cation losses, but that enhanced weathering rates could partly compensate these losses. [ABSTRACT FROM AUTHOR]

Coal extraction in China is increasingly moving towards colder regions such as Xinjiang and Inner Mongolia. However, these mines face land restoration challenges due to a scarcity of fertile topsoil. This study explores the potential of coal gangue, a mining byproduct, as a viable substitute for topsoil. The study examines the effects of humidity fluctuations and freeze–thaw cycles, both individually and in combination, on the weathering disintegration of coal gangue. Coal gangue samples were subjected to controlled laboratory conditions simulating environmental factors. Fourteen interventions were analyzed, and the findings indicated that the combined application of humidity and freeze–thaw cycles significantly accelerated the disintegration process, outperforming the individual interventions. In addition, it was found that significant temperature variations caused the moisture and salts within the gangue to expand, which affected the rate of disintegration. The study showed that the rate of weathering disintegration was significantly higher in conditions of saturated humidity–freeze–thaw cycles compared to unsaturated humidity conditions. This highlights the essential role of ice crystals in accelerating the weathering process during temperature fluctuations. This study highlights the importance of humidity over temperature in the weathering and disintegration of coal gangue. It also suggests that freeze–thaw cycles can enhance this process. The study provides valuable insights for the management and utilization of coal gangue in cold and arid regions. [ABSTRACT FROM AUTHOR]

This study presents the chemical and mineralogical composition of clay deposits and associated rock types within the Ropp Complex in order to assess the influence of parent lithology on the kaolinization, genesis, and utility of the deposit. Representative kaolin samples from E horizons of the weathering profiles and their bedrocks were collected from six sites in the Ropp Complex. Clay mineralogy was determined via the XRD technique, while a geochemical analysis was conducted using XRF, SEM coupled with EDS, and ICP-MS. The results showed that all kaolins dominantly contain kaolinite with a content of 77%–98% except for the AS1 kaolin with only minor kaolinite (20%) but mainly illite (65%). The notably lower crystallinity of kaolinite (HI value of 0.53–1.1) as well as its markedly small grain size is consistent with the formation of kaolinite from intensive chemical weathering of igneous rocks. The AS1 kaolin was probably formed from hydrothermal alteration in the burial stage due to the heating of groundwater by the late volcanism. Mobile trace elements (Sr, Ba, and Eu) exhibited a depletion trend, while immobile elements (Hf, Ta, Th) showed enrichment. The relatively more zirconium in kaolins implies the formation of low-temperature kaolinization. The notably high kaolinite content, accompanied by reasonable levels of Fe2O3 and TiO2, signifies a medium-grade quality. Furthermore, chondrite-normalized rare earth element (REE) patterns exhibit congruent trends in rocks and kaolin samples, indicating a relative enrichment in light rare earth elements (LREEs) alongside a discernible negative Eu anomaly. The abundant kaolinite and silicon–aluminum composition make the kaolins suitable for refractories, pharmaceutics, cosmetics, and supplementary cementitious material (SCM). [ABSTRACT FROM AUTHOR]

Ion-adsorption rare-earth deposits supply over 90% of the global market's heavy rare-earth elements (HREEs). The genesis of these deposits, particularly HREE deposits, has garnered significant attention. To elucidate the metallogenic mechanisms of HREE deposits, a comprehensive study of the weathering profile of granite was conducted in Jiangxi Province, South China. This study focuses on the following two aspects: the petrogeochemistry of HREE-rich granite and the enrichment and fractionation of rare-earth elements (REEs) during the weathering process. The results suggest that the Dabu granites are a typical peraluminous, high-K, calc-alkaline granite series with high silica content (SiO2: 74.5%–76.4%), relatively low phosphorus content (P2O5: <0.05%), and high HREE content (ΣLREE/ΣHREE: 0.16–0.66). Weathering advances the decomposition of minerals and the release of elements. REEs are mainly fixed in the regolith by scavengers, mainly clays, Fe–Mn oxides, and carbonates, and ΣREE can reach 799 ppm in the B horizon. However, HREEs tend to migrate further and preferentially combine with Fe–Mn oxides and carbonates as compared to LREEs, leading to a significant fractionation of REEs in the regolith (ΣLREE/ΣHREE = 0.2–1.1). Additionally, the differential weathering of REE-bearing minerals and the precipitation of secondary REE-bearing minerals are also vital for REE fractionation. [ABSTRACT FROM AUTHOR]

The Cryogenian (ca. 717–635 Ma) snowball Earth glaciations ended with the precipitation of “cap” carbonate successions with negative carbon isotope (δ13Ccarb) values, which have been explained by the addition of various 13C-depleted carbon sources in the deglacial process. These arguments assumed that marine dissolved inorganic carbon (DIC) was enriched in 13C in the synglacial ocean. However, this assumption has not yet been tested, because the synglacial ocean chemistry is unknown. In this study, we carried out detailed analyses of the petrology, carbonate carbon (δ13Ccarb) and oxygen (δ18Ocarb) isotopes, organic carbon (δ13Corg) isotopes, major and minor elemental compositions (Ca, Mg, Mn, Fe, Sr), and iron speciation (total Fe, highly reactive Fe, pyrite Fe) of the carbonate layers (also called synglacial carbonate layers) from the Nantuo Formation (ca. 650–635 Ma) on the Yangtze block, South China. Petrographic observations indicated that the synglacial carbonate comprises dolomicrite, mud-crystal powder dolomite, lime dolomite, and dolomitic limestone, supporting an authigenic carbonate origin, and thus, it potentially recorded the ocean chemistry during the Marinoan ice age. The synglacial carbonate is characterized by extreme Mn enrichment, low Fe/Mn ratios, and low δ13Ccarb (−7‰) values. High Mn contents and low Fe/Mn ratios imply marine redox conditions favoring Mn2+ accumulation and Fe2+ oxidation, while low δ13Ccarb values might be attributed to CO2 degassing of submarine volcanoes as well as low primary burial during the glaciation. Since the δ13CDIC value of the synglacial ocean was lower than the δ13Ccarb values of most cap carbonates, we infer the addition of 13C-enriched DIC or removal of 12C during cap carbonate precipitation, such as through carbonate weathering or organic carbon burial. These findings provide new insights into the nature of Cryogenian glaciation, the origin of cap carbonates, and the aftermath of global glaciation [ABSTRACT FROM AUTHOR]

Salt weathering is a common deterioration phenomenon that affects outdoor cultural properties, and it is important to precisely predict the heat, moisture, and salt transfer in porous materials to suppress salt weathering. Osmosis and osmotic pressure were considered in the field of soil research, especially in clay research, but not in the field of outdoor cultural properties and building materials, which are the main target of salt weathering. Osmosis in clay is supposed to be caused by its surface charge. However, it has been suggested that sandstones and bricks that constitute cultural properties and buildings also have surface charge as clay. Thus, osmosis and osmotic pressure can occur in building materials, which may lead to materials degradation. In this study, we derive basic equations, based on nonequilibrium thermodynamics, for the simultaneous heat, dry air, water vapor, liquid water, cation, and anion transfer in building materials by considering osmosis. This equation was compared with existing model for heat and moisture transfer equations as well as models that considered the salt transfer. Based on the previous research for osmosis in clay, we summarized conditions under which osmosis occurs in building materials and presented an outlook for modeling the physical properties of materials related to osmosis. [ABSTRACT FROM AUTHOR]

The importance of carbonate weathering carbon sinks (CCSs) is almost equal to that of vegetation photosynthesis in the global carbon cycle. However, CCSs have become controversial in formulating carbon neutral policies to deal with global climate problems in various countries, since the carbonate dissolution is reversible. In order to address these controversies, we reviewed recent advances in understanding CCSs and examined the outstanding controversies surrounding them. We have analyzed the five controversies, revealing the existence of CCSs, quantifying their magnitude, clarifying their spatiotemporal pattern, and documenting how they have increased and how they evolved under the background of global change. By addressing these five controversies, we help to bring clarity to the role of CCSs in the carbon cycle of global terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

Water pollution is a major concern for a decaying river. Polluted water reduces ecosystem services and human use of rivers. Therefore, the present study aims to assess the irrigation suitability of the Jalangi River water. A total of 34 pre-selected water samples were gathered from the source to the sink of the Jalangi River with an interval of 10 km and one secondary station's data from February 2012 to January 2022 were used for this purpose. The Piper diagram exhibits that the Jalangi River water is Na+–HCO3− types, and the alkaline earth (Ca2+ + Mg2+) outperforms alkalises (Na+ + K+) and weak acids (HCO3− + CO32−) outperform strong acids (Cl− + SO42−). SAR values ranging from 0.35 to 0.64 show that water is suitable for irrigation and poses no sodicity risks. The %Na results show that 91.18% of water samples are good and acceptable for irrigation. RSC levels indicate a significant alkalinity hazard, with 94.12% of samples considered inappropriate for irrigation. PI findings show that 91.18% of water samples are suitable for irrigation. Apart from the spatial water samples, seasonal water samples exhibit a wide variations as per the nature of irrigation hazards. Gibbs plot demonstrates that the weathering of rocks determined the hydro-chemical evolution of Jalangi River water. This study identifies very little evaporation dominance for pre- and post-monsoon water. The analysis of variance (ANOVA) test illustrates that there are no spatial variations in water quality while seasonal variations are widely noted (p < 0.05). The results also revealed that river water for irrigation during monsoon is suitable compared to the pre-monsoon season. Anthropogenic interventions including riverbed agriculture, and the discharge of untreated sewage from urban areas are playing a crucial role in deteriorating the water quality of the river, which needs substantial attention from the various stakeholders in a participatory, and sustainable manner. [ABSTRACT FROM AUTHOR]

ABSTRACT Joint swarms can be important components of fractured reservoirs. They are often explained as damage around faults or related to mechanical differences between layers, although this does not explain the close spacing of the joints. Joint swarms around Bergen (Norway) are described, which are not related to exposed faults and are not influenced by layering or foliation in the Lower Palaeozoic gneisses. We suggest an evolution whereby: (1) a zone of microcracks develops; (2) one microcrack propagates and becomes connected to a source of mineralising fluid; (3) the fracture becomes a microvein, with a higher tensile strength than the microcracked host rock; (4) another microcrack propagates and the cycle is repeated, producing a zone of microveins; (5) the veins are partly weathered out, producing an apparent joint swarm, or the microveins crack at or near the ground‐surface. Joint swarms in exposed analogues may therefore not occur at reservoir depths. [ABSTRACT FROM AUTHOR]

ABSTRACT Nitrogen‐based compounds are widespread in the environment due to various sources of natural and anthropogenic origin that introduce them from the most reducing form (the acidic ammonium cation) to the most oxidized (the nitrate anion). In addition, some environmental conditions, such as pH and redox potential, favor secondary reactions of nitrogenous compounds. An example of this is the harmful effect of nitrates on cultural heritage (CH), which poses a threat to its preservation. This is due to their high solubility and mobility, which allow them to penetrate the structure of the materials. As a result of their crystallization/dissolution and hydration/dehydration cycles, the precipitation of nitrate salts in the pores causes internal fractures, leading to the subsequent deterioration and loss of the material. The detection of these salts is a straightforward process in analytical chemistry, but it is imperative to use nondestructive and noninvasive analytical techniques, such as Raman spectroscopy, because of the need to preserve CH. In this work, we have compiled the sources and pathways that contribute to the formation of nitrogen‐based compounds, especially nitrate salts in various CH components. Finally, the Raman spectrum characteristic of the nitrate family has also been explained, including the most damaging nitrates found in CH, such as niter, nitratine, nitrocalcite, nitromagnesite, nitrobarite, and nitrammite, and has been compiled. In addition, less common nitrates, some nitrites, and other ammonium compounds have been included in this database. [ABSTRACT FROM AUTHOR]

In the study presented here, the initial (that is, before the start of the process of natural hydrochemical influence) mineral formula of metamict polycrase in the composition of granite pegmatites of the Baltic Shield, applying an uranium natural half-leaching period, was calculated. To investigate the characteristics of immobilization of actinides in the studied polycrase, the absolute and relative uranium contents are compared with the corresponding uranium contents in the original betafite of the same deposit and age. It has been shown that over its geological history, betafite has lost up to 80% of its original uranium content. The proportion of uranium preserved in polycrase is twice as high. It is concluded that the difference in the relative content of uranium (27.3 wt% in polycrase and 31.6 wt% in betafite) cannot be the only reason for the complete oxidation of uranium in betafite, given that in polycrase 30% of uranium is preserved in the tetravalent state. It is more likely that the oxidation of uranium in betafite was primarily a result of the low ionicity of the chemical bonds compared to that in polycrase. This allows us to consider minerals of the euxenite group to be quite promising as matrix materials for the immobilization of actinides. At the same time, an opinion was expressed on the advisability of further comparative studies of Nb–Ta–Ti-oxides of the mineral groups AB2O6 and A2B2O7 for their use at the final stage of the nuclear fuel cycle. [ABSTRACT FROM AUTHOR]

To fabricate metals from the base materials for future Mars exploration, synthesis of representative olivine phases and their structural and spectroscopic characterizations are of crucial importance. Using mechanochemical technique that mimics the mechanical weathering, a complete solid solution of (Mg1−xFex)2SiO4 has been synthesized to investigate the associated crystal chemical properties. X-ray powder diffraction data Rietveld analysis confirms that each polycrystalline sample crystallizes in space group Pbnm. The average crystallite size ranges between 80(1) nm and 223(4) nm. Each lattice parameter increases with increasing Fe-content due to the larger Fe2+ radius than that of Mg2+, following Vegard's rule. For a given nominal chemical composition, substitution of Mg with Fe at the M1-site (4a: 0,0,0) is preferred to the M2-site (4c: x,y,¼). As a consequence, the average Fe-content lies slightly below the equivalence line for x = 0.2–0.8, indicating that the Fe/Mg ratio in the amorphous scattering content is most likely greater than unity. Characteristic Raman spectral features of the olivines have been explained in terms of the chemical composition (x). Simple regression models are demonstrated based on both X-ray diffraction and Raman spectroscopic data for the calculation of Mg/Fe in olivines. Diffuse reflectance UV/Vis spectra RATD analysis shows each olivine phase possesses direct band-gap between 3.38(3) eV and 4.90(3) eV. This study could keep valuable information to relevant databases for future human missions on Mars, in particular, for precise estimation of the representative olivines from the remote X-ray diffraction and spectroscopic data. [ABSTRACT FROM AUTHOR]

The problems of large deformation often occur in strongly weathered carbonaceous slate tunnels with high geostress. In order to control large deformation in the process of tunnel construction, an advanced drilling measure and an advanced pilot tunnel measure are proposed, then relevant field tests are carried out to verify their results. Compared with conventional support measures, the advanced pilot tunnel measure has a better control effect on horizontal convergence and vault settlement, which are reduced by 29.70% and 75.81%, respectively. In addition, the advanced drilling measure provides more advantages in controlling the maximum surrounding rock stress and the maximum steel frame stress, which are reduced by 77.44% and 23.12%, respectively. The results show that the large deformation of a strongly weathered carbonaceous slate tunnel in high geostress cannot be effectively solved by conventional support measures, but the two advanced stress-control measures can effectively reduce deformation of the surrounding rock of the tunnel and decrease the stress of the tunnel's steel frame and surrounding rock. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the usability of the Leeb hardness test in determining changes in strength as a result of atmospheric weathering in works of cultural heritage built with low-strength pyroclastic rocks. To this end, the effects of weathering processes on strength properties were investigated in two building stones commonly used in Niğde province located in the Cappadocia (Turkey) region, which contains the most important works of cultural heritage created using low-strength pyroclastic rocks. The index, strength, mineralogical, and petrographic properties of rocks were first investigated. Then, freeze–thaw (F-T) and salt crystallization (SC) tests, the weathering processes of which consisted of six periods, were performed on samples prepared in cubic form. After the F-T and SC processes, the macro change in the samples and changes in weight loss, uniaxial compressive strength (UCS), and Leeb hardness (HL) values were determined. Highly correlated linear relationships were obtained between the SC and F-T cycles of the samples and the UCS and HL values. The HL test was applied to samples for which the UCS test could not be applied due to the loss of sample integrity after the advancing cycles of the accelerated weathering tests. Linear relationships with high correlation were determined between the UCS and HL values obtained from the samples after the accelerated weathering test. This study revealed that the HL approach could be used as an alternative in modeling the strength parameters of the weathering processes of the structures of cultural heritage built using low-strength rocks. [ABSTRACT FROM AUTHOR]

Weathering process leads to changes in mineral composition, microdefects and mechanical properties of mineral grains, which has a significant impact on the macroscale mechanical properties of granitic rocks. In this paper, four granitic samples with different weathering degrees were investigated using microscale rock mechanics experiments (micro-RME), macroscale rock mechanics experiments (macro-RME) and accurate grain-based model (AGBM). The following conclusions can be achieved. First, quartz is erosionally resistant compared to feldspar and biotite. The weathering products of feldspar and biotite are sericite and chlorite, respectively. Second, with the increasing of weathering degree, the volume fractions of quartz and weathering products increase, meanwhile the volume fractions of feldspar and biotite decrease. Third, during the weathering process, Young's modulus of quartz and feldspar almost keep constant, however, Young's modulus of biotite decreases significantly. Fourth, the weathering process significantly increases the volume of microdefects, including pores and microcracks. Finally, from the viewpoint of the weathering effect, we discovered a negative correlation between quartz content and the macroscale Young's modulus of granites. Highlights: The effect of weathering on the granite at multiscale has been investigated. The quartz is erosionally resistant compared to feldspar and biotite. During weathering process, the strength of quartz and feldspar almost keep constant, however the strength of biotite decreases significantly. During weathering process, the volume fractions of quartz and weathering products increase, and the feldspar and biotite decrease. The weathering process significantly increases the volume of microdefects, including pores and microcracks. [ABSTRACT FROM AUTHOR]

Owing to their application in rock weathering concerning geostructural stability, enhanced geothermal systems, carbon sequestration, and enhanced oil recovery, the effect of rock–brine–CO2 interactions on the microstructural and mechanical properties of rocks has become a prevalent topic. Understanding the interplay among chemical, microstructural, and mechanical processes is essential to comprehend how they affect rock mechanical alteration. In this study, we examined the effects of chemo-mechanical loading on the microstructural features and mechanical alterations of individual components within the rock. Experiments involved exposing the Permian rock samples to either CO2 or N2-rich brine (a control condition) at a temperature and pressure of 100 °C and 1800 Psi, respectively, for varying duration (14 and 28 days). The ionic strength of the solution was adjusted to 1 M using NaCl. Micro-CT image analysis showed the dissolution of clay- and quartz-rich phases followed by their precipitation. After 14 days, the depth of the outer reacted zone reached roughly 1100 µm, and after 28 days, the depth increased to 1500 µm. Microscale mechanical analysis showed decreased indentation modulus of the clay- and quartz-rich phases after reacting with CO2-rich brine. This decrease in indentation modulus was more than 50% for quartz-rich phases for 28 days of reaction and was lower adjacent to the reacted surface. The decrease in mechanical properties was more pronounced at a distance of 400–600 µm from the reacted surface after 14 days of reaction with CO2-rich brine due to the pore-size controlled solubility phenomenon. Experiments conducted at a greater distance from the reacted surface (approximately 5 mm) revealed a weaker clay–quartz interface, possibly due to the formation of microcracks induced by the swelling of clay particles. Results for the N2 condition show a superficial mechanical alteration of the rock constituents limited to a depth of 200 µm from the reacted surface. Highlights: Study investigates chemo-mechanical and microstructural alteration of silicate-rich shale rock by CO2/ N2-rich brines. Dissolution of clay and quartz-rich phases followed by the precipitation of clay and quartz from the transformation of feldspar grains in CO2 condition. The modulus of clay- and quartz-rich zones decreased in reacted areas but increased near the surface in CO2 samples. N2 condition causes superficial mechanical alteration, minimal dissolution. Pore-size-controlled solubility play an important role in the evolution of porosity in the context of rock-fluid interaction. Experiments conducted at a greater distance from the reacted surface indicated a weakened clay–quartz interface under CO2 conditions. [ABSTRACT FROM AUTHOR]

Increased dust emissions from dryland areas and their effects on human health, ecosystem viability, and environmental change are a global concern in the face of the growing climate crisis. Dust plume emissions from the West African landmass, Sahara, and Sahel areas comprise a major fraction of the global aerosol budget. Dust plume intensity is closely related to regional winds (e.g., Harmattan, Sahara Air Layer), the Intertropical Convergence Zone, monsoonal seasonality, marine currents, and physiography. To study terrigenous material emitted from the continent over the last ~260 kyr (late Quaternary), we used X-ray fluorescence spectroscopy (XRF) to analyze a ~755 cm long marine sediment core from the eastern equatorial Atlantic Ocean, resulting in nearly 1400 discrete measurements. Spectral analysis results suggest that concentrations of elements (Rb, Sr, Si, Al) preserved in the sediments are correlated to different types of orbital climate forcing. Chemical weathering intensity indicated by the Rb/Sr ratio was sensitive to seasonal insolation variations controlled by precession cycles (23–18 kyr), which presumably reflects the relationship between monsoonal rainfall and sensible heating of the continent. Spectral analysis of silicate mineral grain size (Si/Al) showed significant 40 kyr cycles that were paced by obliquity. Based on these data, we infer that winter tradewind activity accelerated in response to the intertropical insolation gradient induced by high obliquity. High Rb/Sr ratios during the last glacial maximum and penultimate glacial maximum may have been due to a predominance of mechanical weathering over chemical weathering under dry/cool climates or the dissolution of Sr-bearing carbonates by corrosive glacial bottom waters. [ABSTRACT FROM AUTHOR]

Stone consolidants have been used in conservation practices for decades, with an increasingly interdisciplinary scientific attention to their composition and performance. This article is an ethnographic account of the process of testing a new consolidant's efficacy, drawn from fieldwork and interviews with scientists and heritage professionals involved in a European project in 2013. I illustrate, in line with prior scholarship on laboratory time, how time is a central tool of laboratory control, which must be managed to produce evidence of consolidant efficacy. Yet the 'fast time' of controlled experimental conditions is also suspect for those working in the field of heritage. By tracing the temporal tensions between scientific evidence making, laboratory practice and heritage practitioners' values, I illustrate that the project of materially fixing stone in time means intervening on heritage futures. [ABSTRACT FROM AUTHOR]

A number of regolith-hosted REE occurrences have recently been discovered in the Esperance region in southern Western Australia. This paper summarizes major characteristics of REE mineralization and discusses contributing factors and potential controls. The main aim is to explain why there is a lack of highly sought-after ion-adsorption-clay-type REE deposits across the region despite the presence of the regolith-hosted REE mineralization on a regional scale. Local mineralization mostly occurs as continuous flat-lying enrichment "blankets" within the residual regolith developed over Archaean–Proterozoic granite gneisses and granitoids with elevated REE content. The enriched horizon is commonly located in the lower saprolite and saprock and is accompanied by an overlying REE-depleted zone. This distribution pattern, together with the data on HREE fractionation and the presence of the supergene REE minerals, indicates chemogenic type enrichment formed by supergene REE mobilization into groundwater, downward transport, and accumulation in the lower part of the weathering profile. Residual REE accumulation processes due to bulk rock volume and mass reduction during weathering also contribute to mineralization. It is proposed that climate and groundwater chemistry are the critical regional controls on the distribution of REEs in the weathering profile and on their speciation in the enrichment zone. Cenozoic aridification of climate in southwest Australia heavily overprinted pre-existing REE distributions in the weathering profile. Acidic (pH < 4), highly saline groundwaters intensely leached away any relatively weakly bound, adsorbed or colloidal REE forms, moving them downward. Dissolved REEs precipitated as secondary phosphates in neutral to alkaline environment at lower Eh near the base of the weathering profile forming the supergene enrichment zone. Low denudation rates, characteristic of areas of low relief under the arid climate, are favourable for the preservation of the existing weathering profiles with REE mineralization. [ABSTRACT FROM AUTHOR]

Apatite is present as an accessory phase in many meteorites and is often formed as a secondary product of aqueous alteration. Its propensity to incorporate rare earth elements (REE) results in apatite usually being the main REE‐bearing phase in hydrously altered meteorites. Asteroid Ryugu is thought to have experienced pervasive aqueous alteration and material collected from the surface of Ryugu is expected to provide insight into asteroidal aqueous alteration processes without influence by terrestrial weathering. Morphologies and mineral associations of apatite grains from five rock fragments collected from the asteroid Ryugu by the Hayabusa2 spacecraft were examined and their REE concentrations were measured by synchrotron X‐ray fluorescence (SXRF) spectroscopy. The main minerals associated with apatite are dolomite, magnetite, and pyrrhotite. Grain boundary corrosion of the interfaces between apatite assemblages and the surrounding matrix suggest that paragenetic formation on the asteroid was followed by a later episode of hydrous alteration. Light REE (LREE) concentration levels recorded at 20–150 times those of bulk CI levels together with a steady increase from LREE toward enrichment of medium REE (MREE, up to Er) at 50–400 times bulk CI levels may suggest postgenetic removal of LREE from Ryugu apatite grains by late‐stage circulation of a hydrothermal fluid. [ABSTRACT FROM AUTHOR]

Enhanced rock weathering (ERW), the application of crushed silicate rock to soil, can remove atmospheric carbon dioxide by converting it to (bi) carbonate ions or solid carbonate minerals. However, few studies have empirically evaluated ERW in field settings. A critical question remains as to whether additions of crushed rock might positively or negatively affect soil organic matter (SOM)—Earth's largest terrestrial organic carbon (C) pool and a massive reservoir of organic nitrogen (N). Here, in three irrigated cropland field trials in California, USA, we investigated the effect of crushed meta-basalt rock additions on different pools of soil organic carbon and nitrogen (i.e., mineral-associated organic matter, MAOM, and particulate organic matter, POM), active microbial biomass, and microbial community composition. After 2 years of crushed rock additions, MAOM stocks were lower in the upper surface soil (0–10 cm) of plots with crushed rock compared to unamended control plots. At the 2 sites where baseline pre-treatment data were available, neither total SOC nor SON decreased over the 2 years of study in plots with crushed rock or unamended control plots. However, the accrual rate of MAOM-C and MAOM-N at 0–10 cm was lower in plots with crushed rock vs. unamended controls. Before ERW is deployed at large scales, our results suggest that field trials should assess the effects of crushed rock on SOM pools, especially over multi-year time scales and in different environmental contexts, to accurately assess changes in net C and understand the mechanisms driving interactions between ERW and SOM cycling. [ABSTRACT FROM AUTHOR]

Tropical hardwoods, often used as outdoor wood products, are frequently exposed to the hot and humid conditions in Malaysia. This has led to many studies attempting to develop suitable coatings and establishing maintenance cycles so that product service life can be extended. The objective of this study was to evaluate the surface quality and mechanical properties of both uncoated and coated three Malaysian hardwood species, namely dark red meranti (Shorea spp.), keruing (Dipterocarpus spp.) and keranji (Dialium spp.) after exposure to outdoor condition at different time spans. Surface quality of uncoated and coated with exterior transparent alkyd finished of the samples was evaluated visually as well as employing a profilometer-type equipment. Bending characteristics of outdoor exposed samples were also tested. The results showed that the surface of all coated samples degraded after 48 months of exposure. In addition, after 48 months of outdoor exposure, the modulus of rupture (MOR) values for dark red meranti, keruing and keranji decreased by more than 15% while the modulus of elasticity (MOE) values decreased by approximately 20% for both uncoated and coated samples. Generally, refinishing and maintenance should be performed within 2 years, and the cost of the maintenance should be calculated to ensure that the condition of the wood remains suitable for use as a building material in Malaysia's climate conditions. [ABSTRACT FROM AUTHOR]

Magnetic studies of loess–paleosol sequences have shown that the magnetic properties of loess and its parent material are sensitive to weathering degree. However, the relationship between magnetic properties and weathering processes in red soils of southern China remains unclear due to the diversity of parent rocks and the influence of climate. This study focused on red soils developed on weakly magnetic sandstone, in tropical and subtropical regions of Yunnan, China. The principal element content, magnetic susceptibility, temperature-dependent susceptibility curve (χ–T curve, where χ represents the magnetic susceptibility at the corresponding temperature during the heating and cooling process of the sample, and T represents the temperature during the heating and cooling process.), hysteresis loop and Isothermal Remanent Magnetization (IRM) of the samples were determined, the weathering characteristics and magnetic properties of profile samples were analyzed, and their relationship was examined, as well as the impact of climate change on fine-grained ferrimagnetic minerals and magnetic properties. The results revealed that red soils developed on weakly magnetic sandstone exhibited significant correlations between three magnetic indices, low-frequency magnetic susceptibility (χlf), frequency-dependent susceptibility (χfd), (χpost-pre + χd)/χpara, and the silica-sesquioxide ratio (SAF), indicating that these indices can be used to assess soil weathering. Additionally, this study proposed a new index based on the 1 < Log10Bh < 1.5 mT component obtained from decomposition of the IRM curve, which can also be used to assess soil weathering. The enhancement of magnetic properties in red soils along a single profile was found to be related to the increase in the content of fine-grained ferrimagnetic com-ponents controlled by weathering. Comparing the two climatic regions, it was found that in Yunnan, China, as the climate changes from subtropical humid to tropical humid, the weathering of the red soil profiles becomes stronger, and the fine-grained ferrimagnetic components increase, indirectly enhancing the magnetic properties of red soils. [ABSTRACT FROM AUTHOR]

Embankments have been widely used in the construction of transportation and flood defense infrastructure. Embankments constructed from clays experience a suite of weather-driven deterioration processes that lead to a progressive loss of hydromechanical performance and eventually to failures whose consequences can be severe and costly. This study aimed to predict the time to failure of aging, deteriorating clay embankments supporting transportation infrastructure. A multiphase numerical modeling approach developed to simulate the long-term weather-driven hydromechanical behavior of clay embankments was used to model and simulate the behavior of a number of well-documented embankment failure case histories with known service life and available information to derive the necessary soil properties and climate records. Numerical models were developed for a total of 34 case studies, and numerical simulations were performed to predict the time to failure of the embankments due to progressive, long-term, weather-driven deterioration. Predictions compared well with actual times to failure reported for the simulated case studies. Further, geometries of modeled slides compared well with those measured for actual slides. The models offered insights into the conditions associated with failure, such as displacement patterns and pore pressure conditions. It was observed that as near-surface soil experiences cycles of wetting and drying, and accompanying cycles of swelling and shrinkage, irrecoverable swelling accumulates with time, causing swelling-induced slides. Overall, the numerical modeling approach was proven effective in producing data necessary to develop deterioration models that could improve infrastructure asset management. Practical Applications: This study underscores the importance of understanding and predicting the long-term performance of clay embankments in civil engineering infrastructure. Through the use of long-term numerical modeling, this study could predict the time of weather-driven shallow slides in clay embankments. The ability to predict failures of embankments can offer significant improvements in infrastructure asset management. Predictive models can offer early warning to potential imminent failures, allowing for timely intervention to minimize the risk of sudden, unexpected failures, especially where consequences can be severe and costly. [ABSTRACT FROM AUTHOR]

Constraining the processes that fractionate barium isotopes is essential for utilising barium isotope ratios as environmental tracers. Barium concentration measurements from soils, rivers, and estuaries demonstrate that adsorption–desorption reactions significantly influence the distribution of fluid–mobile barium at the Earth's surface, potentially driving isotopic fractionation. To quantify the direction and magnitude of isotopic fractionation resulting from these reactions, a riverine and an estuarine series of batch experiments were conducted using environmentally important adsorbent minerals and surface waters. Himalayan river sediment and water samples were used to validate the experimental results. Adsorption–desorption reactions were found to be rapid, relative to the average transit time of sediment and water in catchments, and largely reversible. The direction and magnitude of isotopic fractionation in the riverine experiment series were consistent with the riverine field samples (preferential adsorption of the lighter isotopes). The reaction rate, reversibility, and magnitude of isotopic fractionation were found to depend primarily on the mineral. Experiments performed with iron oxyhydroxides (goethite and ferrihydrite) resulted in a greater degree of fractionation compared to clay minerals (kaolinite and montmorillonite). Estuarine experiments, designed to simulate sediment passage through a salinity gradient, demonstrated a high degree of reversibility, with 77% to 94% of adsorbed barium desorbed upon the addition of seawater to freshwater-equilibrated clay minerals. The results of the estuarine experiments suggest that barium isotope ratios measured in marine paleo-archives (e.g. , corals) will reflect both the adsorbed and dissolved freshwater barium inputs to the ocean. The combined findings of this study indicate that the chemical and isotopic behaviour of barium differs from more conventional group 1 and 2 metal isotope systems due to a significant proportion of barium released from bedrock dissolution partitioning to mineral surfaces, rapid reaction rates between fluid–mobile phases, and a high degree of reaction reversibility. Consequently, riverine barium isotope ratios are likely to provide unique insights into the complex array of terrestrial weathering and erosion processes that sustain life on Earth. [ABSTRACT FROM AUTHOR]

Paleoenvironmental archives in East Antarctica have revealed significant changes during the Holocene, marked by ice sheet retreat leading to the isolation of submarine basins. These basins offer valuable insights into past climate, glaciology, and oceanography shifts that impact sedimentary processes. In this study, environmental magnetism and biogeochemical proxies to investigate the Mid-to-Late-Holocene transitions in Pup Lagoon, a coastal isolation basin is presented. Our findings reveal distinct stratigraphic zones reflecting shifts from marine to lacustrine environments. The results reveal predominant mechanical weathering in the Stornes region, producing coarse-grained "soft" ferrimagnetic minerals. Notably, a period of warm oceanographic conditions between 6000 and 4722 cal. yr BP was characterized by mixed magnetic grain sizes and ultrafine superparamagnetic grains, indicating relatively oxic open waters in the basin. Subsequent shifts to reducing conditions coincide with persistent marine sea ice cover from 4722 to 2634 cal. yr BP, favoring the retention of coarse-grained ferrimagnets. Finer magnetic grain sizes between 2634 and 2185 cal. yr BP was attributed to the increased freshwater inputs associated with the Mid-Holocene Hypsithermal. Further, diagenetic changes under persistent sea ice cover between 2185 and 1970 cal. yr BP led to the selective dissolution of fine-grained ferrimagnets. Transitioning to freshwater isolated basin conditions between 1970 and 588 cal. yr BP, fine ferrimagnet precipitation indicate oxic to suboxic conditions alongside drier conditions. Biogenic productivity increased post-isolation, which was reflected in increased (Total Organic Carbon) TOC and (Total Nitrogen) TN percentages. Additionally, the presence of greigite in the isolated phase sediment indicates reducing conditions owing to organic matter decomposition. Notably, χfd% exhibits an inverse trend to sea ice concentration, potentially indicating anoxic-dysoxic conditions due to the presence of sea ice. These observations align with broader regional sea ice concentration changes, emphasizing the interconnected behavior of local and regional factors shaping Antarctic coastal environments. [ABSTRACT FROM AUTHOR]

Oil spills pose significant threats to marine and freshwater environments, impacting ecosystems and drinking water sources. The present review incorporated an up‐to‐date statistical analysis of the oil spills globally including the types and sources of oil spills and the main habitats affected by the past incidents. It presented immediate and long‐term effects on aquatic organisms and habitats highlighting the necessity for action to protect the aquatic environment. The paper also elucidated a range of effective remediation and cleanup methods, presenting a comprehensive toolkit to mitigate ecological damage. Noticeably, the review identified crucial knowledge gaps in the literature: (i) the absence of marine plastic pollution in studies on oil spill impacts and (ii) the absence of a modeling framework that considers the presence of microplastics in the spillage region and their impacts on the overall weathering rate. From synthesizing essential knowledge on oil spill dynamics and identifying the knowledge gap in the literature, this review aims to enhance understanding and guide future research. [ABSTRACT FROM AUTHOR]

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

Recent advancements in cultural heritage preservation have increasingly focused on the development and application of new composites, harnessing the diverse properties of their components. This study reviews the current state of research and practical applications of these innovative materials, emphasizing the use of inorganic phosphatic materials (in particular the hydroxyapatite) and various polymers. The compatibility of phosphatic materials with calcareous stones and the protective properties of polymers present a synergistic approach to addressing common deterioration mechanisms, such as salt crystallization, biological colonization, and mechanical weathering. By examining recent case studies and experimental results, this paper highlights the effectiveness, challenges, and future directions for these composites in cultural heritage conservation. The findings underscore the potential of these materials to enhance the durability and aesthetic integrity of heritage stones, promoting sustainable and long-term preservation solutions. [ABSTRACT FROM AUTHOR]

The different salt weathering issues of the sandstone in the Nankan Grotto have significantly influenced their preservation conditions. This work aimed to evaluate the petrography and environment constraints for salt weathering of three typical sandstones: yellow sandstone, cyan sandstone, and gray sandstone in the Nankan Grotto. Salt resistance test and acid leaching test were conducted on these three sandstones. In addition, the mineralogy, geochemical mass balance, micro-structure, and water transport properties of these sandstones were also analyzed. It is found that yellow sandstone had high quartz concentration, porosity, and water transport ability. Cyan sandstone had low calcite concentration, high porosity and medium water transport ability. Gray sandstone had high calcite concentration, low porosity and water transport ability. The decay of sandstones in the salt resistance test at 20 °C was faster than those at 5 °C and 35 °C. In addition, yellow sandstone was the most resistant to the salt resistance test, followed by cyan sandstone, and gray sandstone was the most vulnerable to the salt resistance test. In the H2SO4 acid leaching test, efflorescence pattern was the most likely type of decay in yellow and cyan sandstones. Thenardite was the exclusive salt in the yellow sandstone, while gypsum was the mainly salt in the cyan sandstone. Gypsum crust and subflorescence were the most common types of decay for gray sandstone. In the HNO3 acid leaching test, yellow and cyan sandstones did not show obvious variations. For gray sandstone, the secondary minerals were gypsum and dolomite, and crust pattern was observed. In general, the salt weathering of gray sandstone was more severe than yellow and cyan sandstones. The differences in petrography (mainly calcite concentration) and micro-structure of sandstone and the external environment leaded to the differences in the types, amounts, and locations of the salt crystallization in the acid leaching tests. These contributed to the different development of efflorescence, subflorescence, and crust patterns. Our research reveals the petrographic, micro-structural, and environmental constraints for different salt weathering processes of sandstones in the Nankan Grotto. [ABSTRACT FROM AUTHOR]

This research delves into the intricate nexus of particle size, mineralogical composition, surface attributes, elemental mapping, and rare earth element (REE) adsorption mechanisms within an ion-adsorption clay sample from South America. The investigation entails the fractionation of the ion-adsorption clay into three size categories: S1 (< 0.25 mm), S2 (0.25–0.5 mm), and S3 (0.5–2 mm). Each fraction undergoes meticulous characterization to unveil its elemental composition, mineralogical composition, surface area, morphological characteristics, elemental mapping, and the mechanisms governing REE incorporation. The results indicate that S1 has 31% physiosorbed, 8% chemisorbed, and 61% mineralized REEs, while S2 has 40% physiosorbed, 5% chemisorbed, and 55% mineralized REEs, and S3 has 24% physiosorbed, 5% chemisorbed, and 71% mineralized REEs. The physisorbed REEs are attributed to the presence of kaolinite, conducive to mostly physisorption. In terms of grain size and REE content/type relationship, the results show that REE content decreases with increasing grain size; however, there is not a clear trend in terms of REE occurrence modes with grain size. Heavy rare earth elements (HREEs) are discernibly favored in adsorption over light rare earth elements (LREEs). This preference is underpinned by the weathering processes that led to the formation of ion-adsorption clay, which facilitated the transport and accumulation of HREEs. Notably, the ion-adsorption clay encompasses a substantial content of mineralized REEs, necessitating more demanding extraction methodologies, such as acid baking followed by water leaching if complete extraction of all REEs is desired. Among the desorbable REEs, physisorption dominates, encompassing over 80% of the total. Chemisorbed REEs exhibit versatility in association with various minerals, encompassing kaolinite, quartz, and goethite. In essence, this study unveils the intricate interplay between particle dimensions, mineralogical constitution, surface attributes, and REE adsorption modes within this ion-adsorption clay sample. The ion-adsorption clay in this study contains a significant portion of mineralized REEs that cannot be extracted using the mild conditions typically employed for the desorption process. Additionally, the REE concentration in this ion-adsorption clay is notably higher than the average found in clay deposits worldwide, reaching levels comparable to those of regolith deposits in China, which are a major global source of REEs. This remarkable concentration of REEs, along with the unique modes of their occurrence in this deposit, presents a significant interest to the scientific community. [ABSTRACT FROM AUTHOR]

The release of phosphorous (P) via chemical weathering is a vital process that regulates the global cycling of numerous key elements and shapes the size of the Earth's biosphere. It has long been postulated that global climate should theoretically play a prominent role in governing P weathering rates. Yet, there is currently a lack of direct evidence for this relationship based on empirical data at the global scale. Here, using a compilation of temperature and P content data of global surface soils (0 to 30 cm), we demonstrate that P release does enhance at high mean annual surface temperatures. We propose that this amplification of nutrient supply with warming is a critical component of Earth's natural thermostat, and that this relationship likely caused expanded oceanic anoxia during past climate warming events. The potential acceleration of phosphorus loss from soils due to anthropogenic climate warming may pose threats to agricultural production, terrestrial and marine ecosystems, and alter marine redox landscapes. [ABSTRACT FROM AUTHOR]

Climate influences near-surface biogeochemical processes and thereby determines the partitioning of carbon dioxide (CO2) in shale, and yet the controls on carbon (C) weathering fluxes remain poorly constrained. Using a dataset that characterizes biogeochemical responses to climate forcing in shale regolith, we implement a numerical model that describes the effects of water infiltration events, gas exchange, and temperature fluctuations on soil respiration and mineral weathering at a seasonal timescale. Our modeling approach allows us to quantitatively disentangle the controls of transient climate forcing and biogeochemical mechanisms on C partitioning. We find that ~3% of soil CO2 (1.02 mol C/m²/y) is exported to the subsurface during large infiltration events. Here, net atmospheric CO2 drawdown primarily occurs during spring snowmelt, governs the aqueous C exports (61%), and exceeds the CO2 flux generated by pyrite and petrogenic organic matter oxidation (~0.2 mol C/m²/y). We show that shale CO2 consumption results from the temporal coupling between soil microbial respiration and carbonate weathering. This coupling is driven by the impacts of hydrologic fluctuations on fresh organic matter availability and CO2 transport to the weathering front. Diffusion-limited transport of gases under transient hydrological conditions exerts an important control on CO2(g) egress patterns and thus must be considered when inferring soil CO2 drawdown from the gas phase composition. Our findings emphasize the importance of seasonal climate forcing in shaping the net contribution of shale weathering to terrestrial C fluxes and suggest that warmer conditions could reduce the potential for shale weathering to act as a CO2 sink. [ABSTRACT FROM AUTHOR]

The Hongjiang—Qianshan fault has abundant medium-low temperature geothermal resources. However, the excessive fluorine concentration in geothermal groundwater restricts the development and utilization of geothermal resources. 20 samples were collected in this region for identifying the genetic mechanism of medium-low temperature of fluoride-enriched geothermal resources. The hydrochemical results indicate that the hydrochemical characteristic of high fluoride geothermal groundwater is HCO3-Na. The groundwater environment is alkaline and weakly alkaline. The fluoride concentration in geothermal groundwater is 2−12 times greater than the upper limited value, while those in the surface water and shallow groundwater are within the permittable threshold range. The isotopic results reveal that the recharge elevations and circulation depth are 797−2186m and 893−1893m, respectively. Quartz provides the most reliable estimations of reservoir temperatures, ranging from 79.4℃ to 113.1℃. The fluoride in geothermal groundwater originates from the rock weathering and mineral dissolution. Cation exchange and alkaline condition are the main influence factors for fluorine enrichment. [ABSTRACT FROM AUTHOR]

The freeze-thaw process is a weathering phenomenon that occurs in rocks and stones when water enters small cracks and pores within the stone. When the temperature drops below freezing, the water inside the rock expands as it freezes, exerting pressure on the rock from within. In this study the effect of freeze thaw on mechanical parameter uniaxial compression strength (UCS) and ultrasonic pulse velocity (UPV) of 47 oolitic samples were considered. At first, capillary absorption for cylindrical and prismatic oolitic samples were measured and then freeze-thaw experiment with 23 cycles were applied to the samples. UPV of samples before and after freeze-thaw was analysed by two ultrasonic devices including Geotron and Pundit. It was observed that freeze thaw decreases primary velocity (Vp) and secondary velocity (Vs) by around 20 and 7% respectively. However, average UCS of 1.6 MPa indicates strength decrease of samples, which represent negative effect of pore expansion due to freeze thaw on strength parameter of samples. [ABSTRACT FROM AUTHOR]

Heritage buildings are crucial for any area's cultural and political aspects. Proper maintenance and monitoring are essential for the conservation of these buildings. However, manual inspections are time‐consuming and expensive. We propose a deep learning–based detection framework to identify the damages on the ancient architectural wall. The algorithm applied in this study is YOLOv5. Comparing its five different versions, it was decided to use YOLOv5m as the most accurate detection algorithm with a mAP of 0.801. The damage types identified are physical weathering and visitors' scratches. High‐resolution images were selected for the experiment and effectively identified image. In addition, the applied algorithm allows real‐time detection and the identification of seasonal sources of disruption, which is proved by the video test in this study. The findings contribute to the development of an intelligent tool for health monitoring with the goal of fast and remote damage detection in the routine maintenance of heritage buildings. [ABSTRACT FROM AUTHOR]