Distinguishing the origin of lunar water ice requires in situ isotopic measurements with high sensitivity and robustness under extreme lunar conditions; however, challenges such as uncertain water contents and isotopic fractionation induced by regolith particles restrict isotopic analysis. Herein, we present a miniaturized tunable diode laser absorption spectrometer (TDLAS) developed as the core prototype for the Chang'E-7 Lunar Soil Water Molecule Analyzer (LSWMA). The wavelength range of the instrument is 3659.5-3662.0 cm-1, and the system integrates a Herriott cell for stable multi-isotope (H2 16O, H2 18O, H2 17O, and HD16O) detection and employs regolith samples of known isotopic experiments to quantify adsorption-induced fractionation. Performance evaluations demonstrated a dynamic water detection range of 0.01-2 wt % and isotope precision up to 1.3 parts per thousand for delta D (30.5 s), 0.77 parts per thousand for delta 18O (36 s), and 0.75 parts per thousand for delta 17O (21.5 s) with extended averaging. Repeated injections of three types of standard water revealed a volume-dependent deviation (Delta delta D up to -59.5 parts per thousand) attributed to multilayer adsorption effects, while simulated lunar soil experiments identified additional isotopic fractionation (Delta delta D up to -12.8 parts per thousand) caused by particle binding. These results validate the ability of the spectrometer to resolve subtle isotopic shifts under lunar conditions, providing critical data for distinguishing water origins and advancing future resource utilization strategies.

Our recent investigations have discovered inward diffusion (in-gassing) of moderately volatile elements (MVEs; e.g., Na, K and Cu) from volcanic gas into volcanic beads/droplets. In this work, we examine the distribution of sulfur in lunar orange glass beads. Our analyses reveal that sulfur exhibits a non-uniform distribution across the beads, forming U or W shaped profiles typical of in-gassing. A model developed to assess sulfur contributions from different sources (original magmatic sulfur versus atmospheric in-gassed sulfur) in the orange beads indicates that atmospheric sulfur in-gassed during eruption contributes approximately 9-24 % to the total sulfur content of an orange bead, averaging around 16 %. This in-gassed sulfur is derived from the eruption plume, where atmospheric sulfur could undergo photochemical reactions induced by UV light, leading to mass independent fractionation and a distinct sulfur isotope signature. Interestingly, a recent study discovered a small mass independent isotope fractionation of sulfur in lunar orange glass beads in drive tube 74002/1 and a lack of such mass independent isotope fractionation in black glass beads in the same lunar sample. This finding contrasts with sulfur in lunar basalts, which typically exhibit mass dependent fractionation. With our work, the observed mass independent fractionation signal in sulfur isotopes of orange beads can be attributed to the in-gassing of photolytic sulfur in the optically thin part of the eruption plume where UV light can penetrate. Using the sulfur isotope data of lunar orange beads, we estimate that the 033S value of atmospheric sulfur is approximately -0.18 %o. Our study provides new insights into the complex dynamics of volatile elements in lunar volcanic processes, highlighting the role of in-gassing in shaping sulfur isotope signatures in volcanic glass beads.

Current models suggest the five regular moons of Uranus formed in a single stage from a primary planetary disk or a secondary impact disk. Using latest estimates of moon masses (Jacobson, 2014), we find a power-law relationship between size and density of the moons due to varying rock/ice ratios caused by fractionation processes. This relationship is better explained by mild enrichment of rock with respect to ice in the solids that aggregate to form the moons following Rayleigh law for distillation (Rayleigh, 1896) than by differential diffusion in the disk, although the two mechanisms are not exclusive. Rayleigh fractionation requires that moon composition and density reflect their order of formation in a closed-system circumplanetary disk. For Uranus, the largest and densest moons Titania and Oberon (R similar to 788 and 761 km, respectively) first formed, then the midsized Umbriel and Ariel (585 and 579 km), satellites in each pair forming simultaneously with similar composition, and finally the small rock-depleted Miranda (236 km). Fractionation likely occurred through impact vaporization during planetesimal accretion. This mechanism would add to those affecting the composition of accreting planets and moons in disks such as temporal/spatial variation of disk composition due to temperature gradients, advection, and large impacts. In the outer solar nebula, Rayleigh fractionation may account for the separation of a rock-dominated reservoir, and an ice-dominated reservoir, currently represented by CI carbonaceous chondrite/type-C asteroids and comets, respectively. Potential consequences for Uranus moons' composition are discussed.

The utilization of mulch stands as a paramount approach in the management of wind erosion and the stabilization of soil and drifting sands. This study aimed to explore the impact of various concentrations of spent liquor (20 %, 30 %, and 50 % v/v) derived from SO2-ethanol-water (SEW) fractionation of Eucalyptus wood on the physical and mechanical properties of sand. These properties encompassed moisture content, thickness, temperature, electrical conductivity (EC), wind erodibility, penetration resistance, and seed germination. The findings revealed that the highest compressive strength (0.76 MPa) was attained with mulch consisting of 50 % SEW spent liquor, resulting in a 3.3-fold increase in penetration resistance compared to the control treatment. Furthermore, the 20 % concentration of spent liquor did not adversely affect the germination of black saxaul (Haloxylon ammodendron), whereas the lowest seed germination rate was associated with the 50 % concentration. Based on the measured parameters, the optimal mulch treatment for stabilizing drifting sands was identified as mulch with a 50 % (v/v) concentration. This study underscores the efficacy of SEW spent liquor in dust control and mitigating its environmental impacts, thus highlighting its potential in sustainable soil management practices.

In the hierarchical model of soil aggregates, small soil microaggregates (small SMA; 40 mu m up to 1700 mu m in maximum. Our study on aggregation in wet-dry cycles revealed that the colloidal content has a controlling effect on the size distribution of resulting aggregates by acting as a binding agent and provides hereby new insights into the evolvement of aggregate hierarchy in soils.

In order to study the processes related to the origin and retention of water on the surface of the Moon, an experimental setup has been created at the Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences (GEOKHI RAS), for the analysis of (re)sublimation processes of water ice in a vacuum at low temperatures. The temperature range for (re)sublimation varies from -100 to 0 degrees C. The setup is connected to an Isotope Ratio Mass Spectrometer (IRMS), which allows for measuring the isotopic composition of the vapor of the evaporating substance and providing an estimation of the (re)sublimation rate under specific physicochemical conditions. The direct introduction of gases into the mass spectrometer in real-time mode sets the developed setup apart from foreign counterparts. The setup is equipped with a transparent quartz window through which the surface of the studied substance can be heated using a halogen lamp, simulating the movement of solar rays on the surface of mineral grain compositions under conditions similar to those on the lunar surface. In addition to studying gas (de)sorption on the surfaces of mineral grains of various compositions, the setup can also be used for researching the (re)sublimation of gas hydrates and CO2.

The origin, evolution, and cycling of volatiles on the Moon are established by processes such as the giant moon forming impact, degassing of the lunar magma ocean, degassing during surface eruptions, and lunar surface gardening events. These processes typically induce mass-dependent stable isotope fractionations. Mass-independent fractionation of stable isotopes has yet to be demonstrated during events that release large volumes of gas on the moon and establish transient lunar atmospheres. We present quadruple sulfur isotope compositions of orange and black glass beads from drive tube 74002/1. The sulfur isotope and concentration data collected on the orange and black glasses confirm a role for magmatic sulfur loss during eruption. The Delta S-33 value of the orange glasses is homogenous (Delta S-33 = -0.029 parts per thousand +/- 0.004 parts per thousand, 2SE) and different from the isotopic composition of lunar basalts (Delta S-33 = 0.002 parts per thousand +/- 0.004 parts per thousand, 2SE). We link the negative Delta S-33 composition of the orange glasses to an anomalous sulfur source in the lunar mantle. The nature of this anomalous sulfur source remains unknown and is either linked to (a) an impactor that delivered anomalous sulfur after late accretion, (b) sulfur that was photochemically processed early during lunar evolution and was transported to the lunar mantle, or (c) a primitive sulfur component that survived mantle mixing. The examined black glass preserves a mass-dependent Delta S-33 composition (-0.008 parts per thousand +/- 0.006 parts per thousand, 2SE). The orange and black glasses are considered genetically related, but the discrepancy in Delta S-33 composition among the two samples calls their relationship into question.

As a moderately volatile, redox-sensitive chalcophile and siderophile element, Te and its isotopic composition can inform on a multitude of geochemical and cosmochemical processes. However, the interpretation of Te data from natural settings is often hindered by an insufficient understanding of the behavior of Te in high-temperature conditions. Here, we present the results of Te evaporation and isotopic fractionation in silicate melting experiments. The starting material was boron-bearing anorthite-diopside glass with 1 wt% TeO2. The experiments were conducted over the temperature range of 868-1459 degrees C for 15 min each, and at oxygen fugacities (logfO(2)) relative to the fayalite-magnetite-quartz buffer (FMQ) of FMQ-6 to FMQ+1.5, and in air. Evaporation of Te decreases with decreasing fO(2). For high-temperature experiments performed at > 1200 degrees C Te loss is accompanied by Te isotope fractionation towards heavier compositions in the residual glasses. By contrast, Te loss in experiments performed at temperatures 1200 degrees C is alpha(K) = 0.99993. At reducing conditions, Te likely substitutes as Te2- for O2- in the melt structure and becomes increasingly soluble at highly reducing conditions. Consequently, Te evaporation is not predicted for volcanic processes on reduced planetary bodies such as the Moon or Mercury. (C) 2022 Elsevier Ltd. All rights reserved.

Permafrost thaw will release additional carbon dioxide into the atmosphere resulting in a positive feedback to climate change. However, the mineralization dynamics of organic matter (OM) stored in permafrost-affected soils remain unclear. We used physical soil fractionation, radiocarbon measurements, incubation experiments, and a dynamic decomposition model to identify distinct vertical pattern in OM decomposability. The observed differences reflect the type of OM input to the subsoil, either by cryoturbation or otherwise, e.g. by advective water-borne transport of dissolved OM. In non-cryoturbated subsoil horizons, most OM is stabilized at mineral surfaces or by occlusion in aggregates. In contrast, pockets of OM-rich cryoturbated soil contain sufficient free particulate OM for microbial decomposition. After thaw, OM turnover is as fast as in the upper active layer. Since cryoturbated soils store ca. 450 Pg carbon, identifying differences in decomposability according to such translocation processes has large implications for the future global carbon cycle and climate, and directs further process model development.

Stable isotope ratios (delta O-18 and delta D) in Antarctic snow and ice are basic proxy indices of climate in ice core studies. The relation between the ratios has important indicative significance for moisture sources. In general, the fractionation characteristics of the two isotopes vary with different meteorological and topographical conditions. This paper presents the spatial and temporal distribution of meteoric water line (MWL) slopes along a traverse from the Zhongshan Station (ZSS) to Dome A in East Antarctica. It is found that the slopes decrease with the increasing distance inland from the coast and the lowest slope occurred at Dome A, where the long-range transported moisture dominates and clear sky snowing have an influence. The slopes in different layers of the snowpack showed a decreasing trend with depth and this is attributed to the fractionation during the interstitial sublimation and re-condensation processes of the water vapor. Frost flower development on the interior plateau surface can greatly alter the depth evolution of the MWL slope. The coastal snow pits also go through the post-depositional smoothing effect, but their influences are not so significant as the inland regions.