This study investigates salt weathering in the indoor, humid environment of China's Jinsha earthen site. Methods such as digital microscope, scanning electron microscopy (SEM), ion chromatography (IC), energy dispersive spectroscopy (EDS), and laser particle size analysis were employed to collect and analyze samples from four heavily weathered walls. The sampling approach took into account differences in depth and height and prioritized the extraction from various weathering layers to unveil the attributes, causes, and mechanisms of salt weathering. The findings indicate that the Jinsha site's eastern segment suffered salt-induced damage, such as powdering, salt crusts, and blistering, due to the presence of gypsum and magnesium sulfate. These salts were primarily sourced from groundwater. Groundwater ions ascended to the site's surface via capillary action, instigating various forms of salt damage. Salt damage severity has a direct link to salt and moisture content. The degradation patterns can be categorized into powder and multi-layered composite deterioration, both seems related to soil particle composition. Powder deterioration tends to occur when the sand content exceeds 40%. This research proposes preservation strategies that focus on managing groundwater and conducting environmental surveillance. These measures are designed to effectively address and mitigate the risks associated with salt damage.

The deterioration of soft rocks caused by freeze-thaw (F-T) climatic cycles results in huge structural and financial loss for foundation systems placed on soft rocks prone to F-T actions. In this study, cementtreated sand (CTS) and natural soft shale were subjected to unconfined compression and splitting tensile strength tests for evaluation of unconfined compressive strength (UCS, qu), initial small-strain Young's modulus (Eo) using linear displacement transducers (LDT) up to a small strain of 0.001%, and secant elastic modulus (E50) using linear variable differential transducers (LVDTs) up to a large strain of 6% before and after reproduced laboratory weathering (RLW) cycles (-20 degrees C-110 degrees C). The results showed that eight F-T cycles caused a reduction in qu, E50 and Eo, which was 8.6, 15.1, and 14.5 times for the CTS, and 2.2, 3.5, and 5.3 times for the natural shale, respectively. The tensile strength of the CTS and natural rock samples exhibited a degradation of 5.4 times (after the 8th RLW cycle) and 2.7 times (after the 15th RLW cycle), respectively. Novel correlations have been developed to predict Eo (response) from the parameters quand E50 (predictors) using MATLAB software's curve fitter. The findings of this study will assist in the design of foundations in soft rocks subjected to freezing and thawing. The analysis of variance (ANOVA) indicated 95% confidence in data health for the design of retaining walls, building foundations, excavation in soft rock, large-diameter borehole stability, and transportation tunnels in rocks for an operational strain range of 0.1%-0.01% (using LVDT) and a reference strain of less than 0.001% (using LDT). (c) 2025 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).

Space weathering has long been known to alter the chemical and physical properties of the surfaces of airless bodies such as the Moon. The isotopic compositions of moderately volatile elements in lunar regolith samples could serve as sensitive tracers for assessing the intensity and duration of space weathering. In this study, we develop a new quantitative tool to study space weathering and constrain surface exposure ages based on potassium isotopic compositions of lunar soils. We first report the K isotopic compositions of 13 bulk lunar soils and 20 interval soil samples from the Apollo 15 deep drill core (15004-15006). We observe significant K isotope fractionation in these lunar soil samples, ranging from 0.00 %o to + 11.77 %o, compared to the bulk silicate Moon (-0.07 +/- 0.09 %o). Additionally, a strong correlation between soil maturity (Is/FeO) and K isotope fractionation is identified for the first time, consistent with other isotope systems of moderately volatile elements such as S, Cu, Zn, Se, Rb, and Cd. Subsequently, we conduct numerical modeling to better constrain the processes of volatile element depletion and isotope fractionation on the Moon and calculate a new K Isotope Model Exposure Age (KIMEA) through this model. We demonstrate that this KIMEA is most sensitive to samples with an exposure age lower than 1,000 Ma and becomes less effective for older samples. This novel K isotope tool can be utilized to evaluate the surface exposure ages of regolith samples on the Moon and potentially on other airless bodies if calibrated using other methods (e.g., cosmogenic noble gases) or experimental data.

Space weathering alters the surface materials of airless planetary bodies; however, the effects on moderately volatile elements in the lunar regolith are not well constrained. For the first time, we provide depth profiles for stable K and Fe isotopes in a continuous lunar regolith core, Apollo 17 double drive tube 73001/2. The top of the core is enriched in heavy K isotopes (delta 41K = 3.48 +/- 0.05 parts per thousand) with a significant trend toward lighter K isotopes to a depth of 7 cm; while the lower 44 cm has only slight variation with an average delta 41K value of 0.15 +/- 0.05 parts per thousand. Iron, which is more refractory, shows only minor variation; the delta 56Fe value at the top of the core is 0.16 +/- 0.02 parts per thousand while the average bottom 44 cm is 0.11 +/- 0.03 parts per thousand. The isotopic fractionation in the top 7 cm of the core, especially the K isotopes, correlates with soil maturity as measured by ferromagnetic resonance. Kinetic fractionation from volatilization by micrometeoroid impacts is modeled in the double drive tube 73001/2 using Rayleigh fractionation and can explain the observed K and Fe isotopic fractionation. Effects from cosmogenic 41K (from decay of 41Ca) were calculated and found to be negligible in 73001/2. In future sample return missions, researchers can use heavy K isotope signatures as tracers of space weathering effects.

Debris flows pose significant threats due to their high velocity and fluid-like consistency. This research evaluates the intricate failure mechanisms of the rainfall-induced debris-flow event in Nenmara, Palakkad district, Kerala, India, on August 16, 2018, through detailed investigations. A geophysical (Multi-channel Analysis of Surface Waves (MASW)) test was carried out to obtain the shear wave velocity (Vs) of substrata. The dewpoint potentiometer and ring shear test were used to assess unsaturated soil strength and residual shear parameters to analyse the progressive failure mechanism of the landslide using the numerical model LS-RAPID. The mineralogical studies in the Nenmara region reveal that the soil originated from charnockite rocks containing quartz and clay minerals. The low Vs of 197 m/s at 2 m depth indicates the loose and unconsolidated soil layer at the site. The debris flow initiates when the pore water pressure ratio (ru) rises to 0.40 with a peak velocity of 11.9 m/s and 13.9 m/s in the X and Y directions, which led to the demolition of 3 buildings and the loss of 8 lives. The deterministic analysis reveals that ru above 0.30 can trigger a landslide near the Nenmara location. The rainfall threshold analysis suggests that 148 mm of daily or 210 mm of continuous rainfall over five days can trigger landslides around the Nenmara region. This research combines geophysical, geotechnical, and numerical simulations to make a substantial contribution to disaster management in comprehending the mechanism of debris flow by identifying triggering factors, and it will help to find the appropriate mitigation measures for future hill area development.

Observations of widespread hydration across the lunar surface could be attributed to water formed via the implantation of solar wind hydrogen ions into minerals at the surface. Solar wind irradiation produces a defectrich outer rim in lunar regolith grains which can trap implanted hydrogen to form and store water. However, the ability of hydrogen and water to be retained in space weathered regolith at the lunar surface is not wellunderstood. Here, we present results of novel and coordinated high-resolution analyses using transmission electron microscopy and atom probe tomography to measure hydrogen and water within space weathered lunar grains. We find that hydrogen and water are present in the solar wind-damaged rims of lunar grains and that these species are stored in higher concentrations in the vesicles that are formed by solar wind irradiation. These vesicles may serve as reservoirs that store water over diurnal and possibly geologic timescales. Solar windderived water trapped in space weathered rims is likely a major contributor to observations of the widespread presence, variability, and behavior of the water across the lunar surface.

Permanently shadowed regions (PSRs) on the Moon are potential reservoirs for water ice, making them hot spots for future lunar exploration. The water ice in PSRs would cause distinctive changes in space weathering there, in particular reduction-oxidation processes that differ from those in illuminated regions. To determine the characteristics of products formed during space weathering in PSRs, the lunar meteorite NWA 10203 with artificially added water was irradiated with a nanosecond laser to simulate a micrometeorite bombardment of lunar soil containing water ice. The TEM results of the water-incorporated sample showed distinct amorphous rims that exhibited irregular thickness, poor stratification, the appearance of bubbles, and a reduced number of npFe0. Additionally, EELS analysis showed the presence of ferric iron at the rim of the nanophase metallic iron particles (npFe0) in the amorphous rim with the involvement of water. The results suggest that water ice is another possible factor contributing to oxidation during micrometeorite bombardment on the lunar surface. In addition, it offers a reference for a new space weathering model that incorporates water in PSRs, which could be widespread on asteroids with volatiles.

For rock structures exposed in the natural condition, water-induced weakening (including water softening and chemical weathering) is thought to be the main reason for its' stiffness and strength degradation, thus it is of great significance to study the mechanical properties of rocks under the influence of water. In this study, a hexagonal close-packed particle assembly (2D) composed of bonded circular particles with same diameter is considered to approximate a typical soft rock, where the composite contact model for rock materials considering the water-induced wakening is adopted to define the microscopic mechanical reactions between particles. Based on homogenisation theory and lattice model, the stress-strain relationship and strength criteria for rock considering water-induced weakening, as well as the quantitative correlation between macroscopic elastic and strength parameters with microscopic parameters are obtained. The effects of water softening and chemical weathering respectively characterised by saturation and mass loss ratio on macroscopic mechanical behaviours of rock are analysed in detail. The long-term ageing effects of water-induced weakening are also analysed. All results are in good agreement with the laboratory test results, verifying the applicability of the theoretical solution for analysing the effect of water-induced weakening on mechanical behaviours of rock.

Asbestos is a silicate mineral that occurs naturally and is made up of flexible fibres that are resistant to heat, fire, and chemicals and do not conduct electricity. Both anthropogenic disturbance and natural weathering of asbestos-containing waste materials (ACWMs) can result in the emission of asbestos fibre dust, which when breathed, can cause asbestosis, a chronic lung illness that happens due to prolonged exposure of such fibre dust, and can cause 'mesothelioma' cancer. Although asbestos mining and its utilisation had been banned in many countries, there is still a significant issue of ACWMs disposal in the built environment and abandoned sites. It is neither practical nor economical to safely eliminate ACWMs from the built environment, and it is estimated that globally, 4 billion metric tonnes of ACWMs require safe management strategies. The toxicity of inhaled asbestos fibre relies on its surface properties, and in particular the distribution of iron, which serves a critical role in pathogenicity by forming reactive free radicals that damage DNA, thereby trigging cancer. Examining the usefulness of higher plants and microbes in the bioremediation of soil contaminated with ACWMs is the prime aim of the review. Higher plants and microorganisms such as lichens, fungi, and bacteria often play a major role in the remediation of soil contaminated with ACWMs by facilitating the bioweathering of asbestos and the removal of iron to mitigate the toxicity of asbestos.

Terrestrial enhanced rock weathering (ERW) is a promising carbon dioxide removal technology that consists in applying ground silicate rock such as basalt on agricultural soils. On top of carbon sequestration, ERW has the potential to raise the soil pH and release nutrients, thereby improving soil fertility. Despite these possible co-benefits, concerns such as heavy metal pollution or soil structure damage have also been raised. To our knowledge, these contrasted potential effects of ERW on soil fertility have not yet been simultaneously investigated. This field trial aimed at assessing the impact of ERW on biological, physical, and chemical soil properties in a temperate agricultural context. To do so, three vineyard fields in Switzerland were selected for their distinct geochemical properties and were amended with basaltic rock powder at a dose of 20 tons per hectare (2 kg.m(-2)). On each field, basaltic rock powder was either applied one year before the sampling campaign, one month before the sampling campaign, or not applied (control) for a total of 27 plots with 9 repetitions of each level. Overall, basaltic rock powder addition had a predominantly positive to neutral effect on soil fertility. Most soil properties showed no significant change either 1 month or 1 year post application. Nevertheless, our study highlighted a significant increase in earthworm abundance (+71 % on average), soil respiration (+50 %) and extractable sodium concentration (+23 %) as early as 1 month post application. The higher soil respiration raises the question of CO2 losses from organic matter mineralization that could limit ERW's efficiency. The increase in sodium raises concerns about a sodification risk potentially damaging soil fertility. These elements now require further investigation before enhanced rock weathering can be considered a viable and secure carbon dioxide removal technology.