Weathering Products Research Articles

Assessment of Borač-Kotlenik magmatic massif rock mass technical properties as potential source for optimal development of regional road infrastructure based on local stone materials

The Borač-Kotlenik magmatic massif in central Serbia is mainly made up of effusive and pyroclastic rocks, formed in three main phases of volcanic activity: 1. dacite and andesite, 2. quartz-latite and dacite, and 3. basaltoid rocks. Rock mass samples from this magmatic massif have been examined and mined in numerous localities during the XX century for purposes of building and reconstruction works of local and regional road networks. The examination process continues today for purposes of ‘Morava corridor’ highway building and its demand for the local stone material of the specified quality. The results of rock mass technical properties' tests have shown that its quality for road building purposes depends significantly on petrologic type, soundness, and hydrothermal alteration type. Oxidation alteration types can cause a significant decrease in compressive strength, an increase in porosity and water absorption, especially as oxidation chemical processes cause increased susceptibility to weathering, thus making the rock mass unusable in road construction profile layers above the embankment. Testing results demonstrate that effusive volcanic rocks of the Borač-Kotlenik magmatic massif generally can be used in the road building process. For this purpose, it is necessary to select the conformable rock mass zones at each locality, where hydrothermal alteration and weathering products are absent in order to obtain the best available stone material of volcanic origin.

How Are Weather and Climate Products and Decision Support Systems Used in Wildland Fire Decision Making in the US Southwest?

Abstract Wildland fire management is a challenging environment in which to utilize scientific information. Despite the robust information system that supports US wildland fire management, recent studies demonstrate that some data/information products and decision support tools available to that community are not being used to their full potential. In the US Southwest the convergence of climate change, past wildland fire policy, and an expanding wildland urban interface has increased pressure on wildland fire managers to use science-based information to improve management outcomes. This tension between the perceived need for more science in fire management and the practical challenges of using science to inform decisions led us to ask two basic questions: 1) How is information about weather and climate used in wildland fire management decision making in the Southwest? 2) How are decision support tools used in Southwest wildland fire management? We found: relatively few sources of weather and climate information are consulted by Southwest wildland fire managers; a small percentage of those sources are used to inform the specific decisions and tasks we asked about; decision support tools are commonly used to justify rather than inform decisions. We further found evidence that suggests that products and tools that are thoughtfully designed to fit within the specific information use environment of wildland fire management—rather than being produced in isolation from that environment—are more likely to be used and therefore have more impact than those that are produced in isolation from that environment.

Clay mineralogy in mylonite weathering products from Njimom (west Cameroon): origin and terracotta suitability

This study investigated the mineralogical assemblage of weathering products developed on mylonite rocks in west Cameroon. Smectite and vermiculite occurrence was studied, particularly to emphasize its origin and the potential of the samples in terracotta production. Samples characteristics were determined through X-Ray Diffraction (XRD) and X-ray Fluorescence (XRF) methods. Weathering products were observed along road trenches of 450 m long and 50 m height on a syenitic basement rock intruded by magmatic rock veins. Clay minerals are mainly composed of kaolinite and illite. 2:1 swelling clay minerals (vermiculite, montmorillonite) occur in some samples mainly originated from the contact between weathering materials and quartzo feldspatic bands. The main oxides are SiO2 (46–72%), Al2O3 (16–31%), Fe2O3 (2–16%) and K2O (0.1–6%). Vermiculite may be formed by fluid-mineral interactions during alteration of the chlorite in the plasmic microsystems of the soil. Structural changes in the upper part of the saprolite leading to the transformation of vermiculite into smectite under supergene alteration control, which predominates in humid tropical zones. Heavy rainfall leads to the formation of kaolinite at the expense of 2:1 clay minerals. Empirical classification revealed that the studied weathering products can be used to produce common bricks.

Triple oxygen and hydrogen isotopes of glacial diamictites record crustal maturation and changing surface conditions through geologic time

The triple oxygen and hydrogen stable isotopic compositions of 24 glacial diamictite composites with depositional ages from 2.9 to 0.3 Ga are used to reconstruct the evolution of the continental crust and surface environments. The δ18O of the diamictite composites increases from the Archean to the Phanerozoic by ~4 ‰ (3–5 ‰ in Mesoarchean to 13.5 ‰ in Neoproterozoic), a trend that is comparable to those seen in shales and granites, although the diamictites plot on the lower δ18O end of the range seen in shales. The Δ’17O0.528 decreases from −0.04 to −0.15 ‰, overlapping with shales and granites. Nine zircon separates extracted from individual diamictites also show a ~3 ‰ increase in δ18O from 3.75 to 4.5 ‰ to 7 ‰ between 2.9 and 0.6 Ga. The δ18O of diamictites and zircon separates negatively correlates with ɛNd(i) of the diamictites, suggesting that the longer the rocks reside in the upper continental crust (the lower the ɛNd), the more they are subjected to repeated weathering cycles, thus acquiring a higher δ18O and lower Δ’17O0.528 during each cycle. On a triple O isotope plot (δ17O vs δ18O), diamictites define an array with a slope of 0.523, analogous to granites and shales.The δD values of nearly all diamictites overlap with the typical mantle and crustal ranges of −58 ± 12 ‰ and − 69 ± 24 ‰, respectively, but are on the lower end of coeval shale values. Water, contained primarily in sheet silicates, ranges from 2.85 wt% (pre-2.4 Ga) and 2.35 wt% (post-2.4 Ga), showing no temporal change. The youngest diamictites (0.3 Ga Dwyka Group) exhibit low δD values of −105 to −111 ‰, lower than the typical crustal values, potentially reflecting the near-polar position of South Africa at the time of their deposition, which is corroborated by the reconstructed δ18O value of −26 ‰ based on triple oxygen isotopic systematics.The chemical index of alteration (CIA) allows inverting measured δ18O and Δ’17O values of diamictite composites into a pure weathering product (wp) end member by subtracting values of coeval unweathered crust based on tzircon δ18O. This reveals that the δ18Owp also increases with time, suggesting that the increase in δ18O (decrease in Δ’17O) of the maturing crust is insufficient to fully explain the trends. Therefore, at least part of the increasing δ18Owp likely reflects increasing δ18O of the hydrosphere. Reconstructed surface temperatures around the time of diamictite deposition using δ18Owp and Δ’17Owp display a general decrease since the Archean. Given the diagenetic and post-diagenetic history experienced by the diamictites, the temporal and global trends should be interpreted with caution. Nonetheless, reconstructed δ18Owater shows an increase from −21 ‰ at 2.9 Ga to −11 ‰ at 0.6 Ga. Thus, diamictites, like shales, broadly monitor the evolution of surface conditions on Earth from warmer to colder and from lower to higher δ18Owater values of the hydrosphere.

Mineralogy and geochemical controls on the distribution of REY-Ga-Se-Nb enrichment in the No. 6 Coal Seam, Soutpansberg Coalfield, South Africa

Coal is being explored as a potential alternative source for rare earth elements (REY + Sc), which are critical for advancing modern technology. Previous research has mainly focused on assessing the concentration and distribution of REY + Sc in coals from South Africa. However, the modes occurrence of these elements in coal is yet to be investigated. This study offers new insights on the mineralogy and inorganic geochemistry of the No. 6 Seam coal from the Soutpansberg Coalfield (South Africa). The objective is to investigate the distribution, enrichment, and modes of occurrence of critical elements such as Ga, Se, Nb, and REY + Sc within this coal. The No. 6 Seam is a medium rank-B, moderate vitrinite (avg. 41.5 vol%) coal, and contains major minerals such as kaolinite, quartz, and minor minerals including muscovite, siderite, dolomite, pyrite, and calcite. The total REY + Sc concentrations in the coal samples range from 79.9 to 332.1 mg/kg (avg. 213.2 mg/kg; whole-coal/rock basis), higher than global averages for hard coal. The upper continental crust (UCC) normalized concentration coefficients (CC) of the coal shows enrichment of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb, and Y. Distinct REY + Sc enrichment patterns are observed across different coal horizons, divided into two categories: light-REY (LREY) and medium-REY (MREY) in the bottom horizon coal [bottom-upper (BU) and bottom-lower (BL)], whereas the middle horizon coal [middle-upper (MU) and middle-lower (ML)] are enriched in medium-REY (MREY) and heavy-REY (HREY). The BU and BL samples show greater REY + Sc enrichment relative to the MU and ML samples. The samples also contain elevated concentrations of Ga (max. 106.1 mg/kg), Se (max. 50.9 mg/kg), and Nb (max. 14.8 mg/kg), exceeding the average values reported for Chinese coals.When considering the correlations between REY + Sc and major oxide elements, minerals, and organic petrographic assemblages, REY + Sc appears to be more closely associated with inorganic fraction, particularly aluminosilicate (such as kaolinite) and carbonate minerals (like dolomite), rather than with the organic fraction. The kaolinite and dolomite represent mostly detrital input and epigenesis, respectively. Gallium in the coal is primarily associated with aluminium oxide-hydroxide, Nb with minerals such as clay, rutile/anatase, and zircon; and Se with pyrite. Redox-sensitive elemental ratios of Al2O3/TiO2 andTiO2/Zr suggest that the detrital components of the No. 6 Seam coals were predominantly derived from a source consisting of felsic-intermediate rocks. These materials likely represent the weathering products of magmatic rocks from the passive-continental margin tectonic framework of the Limpopo Mobile Belt. Paleoclimatic conditions are inferred to be warm-humid to hot, with the peat deposited under suboxic-to-oxic environments. High values of critical REY percentage (REYdef,rel%: 29.85 to 39.75 %) and an outlook coefficient ≥ 0.7 suggest these Soutpansberg coal samples to be promising for REY + Sc recovery along with Ga.

Soils in Understanding Land Surface Construction: An Example from Campania Plain, Southern Italy

The contribution of sediment transport and accumulation to soil formation was investigated in an area characterized by continental sedimentary activity since the Late Pleistocene. The area was the north-eastern portion of the large Quaternary graben represented by the Campania Plain, which is rimmed to the north–east–south by the Mesozoic carbonate Apennine nappes. The plain was filled mainly by products generated by eruptions from the Phlegrean Fields, which were also distributed on the slopes bordering the plain and remobilized toward the adjacent surfaces. Five sites were selected in the area in question. They were studied using morphological features and pertinent characteristics of the mineral soil fraction >2.0 mm, such as their volume and lithological description. Soils were compared to selected lithostratigraphic sequences characterizing the studied area, which were collected from literature and reinterpreted in pedological keys. The results showed that soils derived from the emplacement of Phlegrean primary volcanic materials, such as Campania Ignimbrite (~39–40 ky B.P.) and Neapolitan Yellow Tuff (~15 ky B.P.), with the related weathering products, and from volcanic materials reworked and transported by alluvial/colluvial episodes. The latter formed contrasting soil horizons which, differing in both rock fragment content and lithological composition, testified to the presence of lithological discontinuities. The formation of the horizons in question interrupted the genetic sequence derived from the in situ alteration of the volcanic substrata, suggesting that processes of transport and redistribution of sediments from the adjacent mountain slopes contributed to soil formation. The comparison of the pedostratigraphies with the lithostratigraphic sequences indicated a strong relation between geomorphic and pedogenetic events.

Oxidative weathering of pyrite in acidic environments: Data-driven experimental evaluation coupled with Raman hyperspectral imaging

This study deals with the identification of the factors that affect pyrite oxidation in acid mine drainage conditions. For this scope, weathering experiments have been carried at laboratory scale based on the design of experiments methodology to evaluate the effect of factors such as major ion concentrations, crystal size, and humic acids presence over the amount of elemental sulfur produced due to the involved weathering reactions. In particular, metal and anionic concentrations in solution were quantified by inductively coupled plasma-atomic emission spectroscopy and ion-chromatography techniques, respectively, whereas the amount of elemental sulfur was quantified with a high-performance liquid chromatography with diode-array detection technique after proper extraction procedure. A partial least squares regression was calculated to establish a quantitative relationship between the considered factors and the amount of elemental sulfur. After evaluation of the model, ferric iron, crystal size and the presence of humic acids were identified as the relevant factors for pyrite oxidation under acidic conditions. In addition, the surface of the samples was characterized by Raman imaging spectroscopy and subsequently analyzed by explorative hyperspectral analysis methods to assess the spatial distribution of the elemental sulfur as the main weathering product, resulting in a homogenous distribution.

The Roman villa at the Castle of Baia (Naples, Italy): investigations on the polychromy of frescoed surfaces by using non-destructive spectroscopic techniques

During the Roman age, the southern promontory of the gulf of Baia was the perfect location for the construction of villae maritimae for the Roman élite that decided to spend their summer residences by the sea.One of these residences is now located in the military fortress of the Castello Aragonese di Baia, built in 1495 CE during the Aragonese period (15th century). Here, during restoration works, the ruins of the residential sector of the villa, which historical sources ascribe to Caesar, were unearthed. The most representative evidence of this is the outstanding in situ remain of mosaics, decorated plasters and finely frescoed surfaces decorated according to the repertoire of the II style. This research aims to investigate the polychromy of a wall decoration representing a perspective depiction of architectural scenes en trompe l'oeil analysed by means of a multi-analytical, non-destructive approach performed in situ. The combined use of spectroscopic techniques (portable X-ray fluorescence, Raman and Fourier Transform Infrared Spectroscopy) points out the use of a characteristic Roman palette, quantitatively assessed by colorimetric measurements. It consists of red and yellow ochre, calcite, hematite, organic black pigments, precious materials such as cinnabar and Egyptian blue, green copper compounds. Fourier Transform Infrared Spectroscopy also revealed the presence of synthetic resins, likely used for the conservation of mural paintings. These are, however, damaged by atmospheric humidity, as detected by Infrared Thermography. Gypsum has been identified as the main weathering product.

Measuring enhanced weathering: inorganic carbon-based approaches may be required to complement cation-based approaches

The removal of atmospheric carbon dioxide (CO2) is now essential to meet net zero goals and limit the impacts of climate change. Enhanced weathering is a method of sequestering CO2 that involves the distribution of finely ground silicate rocks over agricultural land. The weathering of these silicate rocks releases cations into solution which can balance dissolved inorganic carbon, effectively removing CO2 from the atmosphere. Despite being a promising method of carbon dioxide removal (CDR), enhanced weathering has been limited by uncertainty surrounding the measurement of CO2 sequestration. This study compares current measurement approaches that focus on quantifying inorganic carbon and cations within the soil and leachate. Cation-based calculations of CDR were compared to inorganic carbon-based calculations of CDR and soil results were compared to leachate results. The recovery rate of cations in the soil fraction was also tested. Three different ground silicate minerals/rocks – basalt, olivine and wollastonite, were mixed with two different soils and were allowed to weather over 16 weeks in 320 pots with and without plants under different watering regimes and the application of an acidifying fertiliser. Soil and leachate samples were analysed for cations by ICP-OES and inorganic carbon by direct CO2 analysis after acidification and total alkalinity titration (in leachate only). The results indicate that the soil retains most enhanced weathering products through the cation exchange reactions. CDR estimated by cations is often greater than CDR estimated by inorganic carbon. Measurement approaches to estimate cations are susceptible to incomplete or improper accounting through the under-extraction of cations stored within the soil-exchangeable pool, the activity of non-carbonic acids and CO2 outgassing. Inorganic carbon-based measurements, including direct inorganic carbon and total alkalinity analysis, are also complicated by the potential for CO2 loss through carbonate precipitation and re-equilibration. Therefore, inorganic carbon-based approaches and cation-based approaches should be reconciled to validate the estimation of CDR. The inorganic carbon-based estimation of CDR in leachate should equal the cation-based estimation of CDR in leachate—which will be achieved after quantification or estimation of the natural mechanisms that affect each approach. These findings will support the development of accurate measurement processes for enhanced weathering.

Germanium distribution in Mississippi Valley-Type systems from sulfide deposition to oxidative weathering: A perspective from Fule Pb-Zn(-Ge) deposit, South China

Abstract Germanium (Ge) is a critical raw material for emerging high-tech and green industries, resulting in considerable recent interest in understanding its distribution and geochemical behavior in ore deposits. In this contribution, the distribution of Ge and related trace elements in the Fule Pb-Zn(-Ge) deposit, South China, is investigated to reveal the distribution of Ge in the hydrothermal ores and during sulfide weathering, using multiple microanalytical techniques, including scanning electron microscopy, electron probe microanalysis and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). In the Fule MVT deposit, sphalerite (ZnS) is the most significant Ge-carrier relative to other sulfides, though the five recognized textural types of sphalerite display progressive depletion in Ge from the first sphalerite generation to the late one. In the early stage, sphalerite with fine-grained chalcopyrite inclusions has the highest Ge concentrations, probably accounting for a significant proportion of the total Ge. We interpret that high Ge concentrations in the early sphalerite may be attributable to high Cu activity in the mineralizing fluids. During oxidative weathering, Ge was redistributed from its original host, sphalerite, to the weathering product willemite (Zn2SiO4) rather than smithsonite (ZnCO3), with high levels of Ge (up to 448 μg/g) present in the willemite. The formation of abundant willemite largely prevents the dispersion of Ge during weathering. In principle, willemite-hosted Ge should be fully recoverable, and the Zn-silicate ores may, therefore, be a potential target to meet future demand. This study provides new information on how Ge behaves from sulfide- to weathering-stage in MVT systems, which directly impacts Ge mobility and deportment changes and the development of metal-lurgical strategies for Ge recovery.

Forecasting livestock feed sales using machine learning techniques: an analysis of the Moroccan market

Agriculture, especially cereals, is important in sustaining economies and food security globally. This study delves into the Moroccan agricultural landscape, specifically focusing on predicting livestock feed sales to assist cereal company producers in optimizing production, streamlining supply chain operations, and enhancing customer satisfaction. Data collected from various markets across Morocco, including sales dates and locations, was combined with climate data and analyzed using advanced machine learning techniques, particularly the gradient boosting regression (GBR) algorithm, which achieved high accuracy with a mean absolute error (MAE) of 0.0203 and a root mean square error (RMSE) of 0.0281. The evaluation of multiple regression models revealed promising results, demonstrating the effectiveness of predictive models in accurately forecasting sales. These findings contribute valuable insights to sales forecasting in the cereal industry by considering weather conditions, production methods, and livestock-related variables, highlighting the importance of leveraging advanced machine learning techniques for optimizing production processes and meeting market demands efficiently in the agribusiness sector.

Diversity of Fungal Community and Its Constraints in the Yifeng Lithium Mines, Eastern China.

It is well accepted that biodiversity and ecosystem functions are strongly shaped by environmental conditions; however, relatively little is known about how they depend on the mineralogical assemblage of local environments, especially in mines. This study aims to reveal the diversity characteristics of the fungal community in the surface of granite lithium ores and their weathering products sampled from the Yifeng lithium mines in Jiangxi Province, eastern China. According to the analysis of internal transcribed spacer1 (ITS1) high-throughput sequencing, significant differences in fungal community diversity on the surface of lithium ores and their weathering products have been revealed. The operational taxonomic unit (OTU) of the ore surface and its weathering products ranged from 280 to 624, which may depend on the mineral composition as well as the degree of weathering. The community composition of each sample was significantly different at the phylum level, especially between the weathering products in Ascomycota and Basidiomycota. Although Ascomycota and Basidiomycota were the dominant fungal communities in all samples, each sample has its own distinctive fungi. The trophic modes of the fungi were more complex than that of the bacteria. 10 different fungal trophic modes and 25 dominant functional fungal groups were disclosed, and the saprophytic community was found to be the dominant group. These fungi could accelerate the decomposition of environmental organic matter in the environment by producing hydrolases and oxidases. Chytridiomycota with the function of producing and regulating secondary metabolites were the representative fungi in all samples. Our findings would provide theoretical basis and research clues for understanding the relationship between weathering of granite lithium and fungal communities.

Exploring polystyrene weathering behavior: From surface traits to micro(nano)plastics and additives release

Plastic weathering in the natural environment is a dynamic and complex process, where the release of microplastics, nanoplastics and additives poses potential threats to ecosystems. Understanding the release of different weathering products from plastics is crucial for predicting and assessing the environmental hazards of plastics. This study systematically explored these phenomena by exposing polystyrene (PS) to UV irradiation and mechanical agitation for different durations (1 day, 5 days, 10 days, 20 days). The degree of aging, yellowing, brittleness, and the abundance of carbonyl (CO) functional groups in PS were all gradually increasing over time. The weathering pattern of PS surfaces manifested as initial particle oxidation followed by later cracks or flakes formation. The release of products was positively correlated with the aging degree of plastics, as well as among the various released products. Laser infrared and Raman tests indicated that, for microplastics, the size range of 10–20 μm consistently dominated over time, while the primary size range of nanoplastics shifted towards smaller sizes. Additives and other soluble products were prone to release from weathering plastics, with 20 different chemicals detected after 20 d. The release of plastic additives was closely related to aging time, additive type, and quantity. This study contributes to our understanding of the weathering process of plastics, clarifies the release patterns of products over time, and the relationships among different products. It helps predict and assess the environmental pollution caused by plastics.

Enhanced seasonality of the East Asian monsoon indicated by prevailing hydroxy-interlayered vermiculite formation since 1.8 Ma

The seasonality of the East Asian monsoon is characterized by the coexistence of warm and humid summers and cold and dry winters. However, the current understanding of when and why the seasonality of the East Asian monsoon occurs is poor. Hydroxy-interlayered vermiculite (HIV), which is formed under conditions of low soil organic matter content, pH values between 4.6 and 5.8, and oxidizing states with frequent wetting‒drying cycles, may serve as a potential indicator of monsoon seasonality variation. In this study, we present detailed mineralogical and micromorphological investigations of HIV collected from an eolian sequence on the Chinese Loess Plateau (CLP) to explore the evolution of East Asian monsoon seasonality. The mineralogical results deduced from X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy show that a transition from chlorite to HIV occurred at ∼1.8 Ma. Moreover, the authigenic origin of HIV, as indicated by the presence of many neatly arranged flakes in the SEM images and the presence of irregularly interstratified chlorite-HIV observed via transmission electron microscopy (TEM), collectively imply that HIV is the weathering product of chlorite. This transition from chlorite to HIV generally reflects an increase in monsoon seasonality on the CLP since ∼1.8 Ma, which may be caused by the contemporaneous uplift of the northeastern Tibetan Plateau, or global cooling in combination with La Niña-like sea-air interactions. Our study suggests that the HIV serves as an effective index for monsoon seasonality reconstruction, thus providing a new insight into Asian monsoon dynamics.

Weathering-induced organic matter enrichment in marine-continental transitional shale: A case study on the early Permian Taiyuan Formation in the Ordos Basin, China

A comparative analysis of the factors controlling organic matter (OM) enrichment between marine-continental transitional (transitional hereafter) and marine or lacustrine shales is lacking. The early Permian Taiyuan Formation in the Ordos Basin, deposited during a shift from marine to continental settings in northern China, provides a unique opportunity to unravel the differences in OM enrichment mechanisms among these shales. The Taiyuan Formation is characterized by high TOC content (average 4.50%) and kerogen type II2-III. Most samples are thermally mature with a few high to post-mature samples relating to the Late Jurassic–Early Cretaceous Yanshanian magmatism. Rare earth elements and yttrium (REY) are dominated by light- and medium-types enrichments, with distinctly positive Gd anomaly, likely due to seawater incursion. A warm and humid climate prevailed during deposition of the Taiyuan Formation, consistent with the tropical-subtropical location of the North China Plate in the early Permian. The climatic conditions promoted intense continental weathering as reflected by high Th/Sc ratios, chemical index of alteration values, and feldspar alteration to scaly kaolinite. The V/(V + Ni) ratio is inconsistent with the other redox proxies, presumably due to variations in the redox buffer supply in the transitional facies (e.g., OM and pyrite), varying burial rates and dissimilar redox potential of different elements. Hence, this proxy should be interpreted with caution in such settings. Most redox proxies indicate oxic bottom water during deposition of the Taiyuan Formation transitional shale, in contrast to typical OM enriched marine and lacustrine shales where redox stratification or euxinic conditions are common. Instead, the dominant factor for OM enrichment in transitional shales appears to have been a high influx of terrestrial weathering products, including abundant higher-plants OM, associated with preservation of OM due to rapid burial. This process minimizes the detrimental effects of oxic conditions on OM accumulation in the transitional shale facies. This mechanism may hold relevance for analogous basins elsewhere.

Fe-rich X-ray amorphous material records past climate and persistence of water on Mars

X-ray amorphous material comprises 15-73 wt.% of sedimentary rocks and eolian sediments in Gale crater. This material is variably siliceous and iron rich but aluminum poor. The presence of volatiles is consistent with the existence of incipient weathering products. To better understand the implications of this material for past aqueous conditions on Mars, here we investigate X-ray amorphous material formation and longevity within terrestrial iron rich soils with varying ages and environmental conditions using bulk and selective dissolution methods, X-ray diffraction, and transmission electron microscopy. Results indicate that in situ aqueous alteration is required to concentrate iron into clay-size fraction material. Cooler climates promote the formation and persistence of X-ray amorphous material whereas warmer climates promote the formation of crystalline secondary phases. Iron rich X-ray amorphous material formation and persistence on Mars are therefore consistent with past cool and relatively wet environments followed by long-term cold and dry conditions.

Identification and distribution of fluoride in Singkep Island, Lingga Regency, Riau Islands

The consumption of fluoride below the safe limit can result in dental caries, while high concentrations can lead to fluorosis, which can potentially impair the body's systems. One geological factor that influences the concentration of fluoride in water is the type of rock through which the water passes, including granite and its weathering products. The area is located within the Tandjungbuku Formation, which is predominantly composed of granite rock and contains several areas with Mining Business Permits (IUP) for commodities such as silica sand. This research serves as a form of mitigation in response to mining activities, post-mining, and the development of an industrial area. One anticipated impact is an increase in fluoride concentration in the research area, originating from both natural geological processes and human activities. The investigation involved geological mapping, petrographic analysis, XRD, and XRF analysis. Water sampling was conducted for both surface water and groundwater from wells in Resang Tandjungbuku Village. The research area consists of two rock units: granite, which acts as a non-aquifer layer, and colluvial deposits, which function as a free aquifer. Petrographic analysis identified minerals associated with fluoride, such as plagioclase, amphibole, and biotite. This was supported by XRD analysis with the presence of biotite, muscovite and kaoline minerals. XRF results revealed fluoride values in granite rock at 0.23% or 2300 ppm, further confirming granite as a source of fluoride. Analysis of fluoride in surface water showed values ranging from 0.01 to 4.24 mg/L, while groundwater consistently had a value of 0.01 mg/L.

The Use of Weather, Water, Ice, and Climate (WWIC) Information in the Polar Regions: What Is Known after the Decadelong Polar Prediction Project?

Abstract The polar regions are facing a wide range of compounding challenges, from climate change to increased human activity. Infrastructure, rescue services, and disaster response capabilities are limited in these remote environments. Relevant and usable weather, water, ice, and climate (WWIC) information is vital for safety, activity success, adaptation, and environmental protection. This has been a key focus for the World Meteorological Organization’s (WMO) Polar Prediction Project (PPP), and in particular its “Societal and Economic Research and Applications” (PPP-SERA) Task Team, which together over a decade have sought to understand polar WWIC information use in relation to operational needs, constraints, and decision contexts to inform the development of relevant services. To understand research progress and gaps on WWIC information use during the PPP (2013–23), we undertook a systematic bibliometric review of aligned scholarly peer-reviewed journal articles (n = 43), examining collaborations, topics, methods, and regional differences. Themes to emerge included activity and context, human factors, information needs, situational awareness, experience, local and Indigenous knowledge, and sharing of information. We observed an uneven representation of disciplinary backgrounds, geographic locations, research topics, and sectoral foci. Our review signifies an overall lack of Antarctic WWIC services research and a dominant focus on Arctic sea ice operations and risks. We noted with concern a mismatch between user needs and services provided. Our findings can help to improve WWIC services’ dissemination, communication effectiveness, and actionable knowledge provision for users and guide future research as the critical need for salient weather services across the polar regions remains beyond the PPP. Significance Statement Every day, people in the Arctic and Antarctic use weather, water, ice, and climate information to plan and carry out outdoor activities and operations in a safe way. Despite advances in numerical weather prediction, technology, and product development, barriers to accessing and effectively communicating high-quality usable observations, forecasts, and actionable knowledge remain. Poorer services, prediction accuracy, and interpretation are exacerbated by a lack of integrated social science research on relevant topics and a mismatch between the services provided and user needs. As a result, continued user engagement, research focusing on information use, risk communication, decision-making processes, and the application of science for services remain highly relevant to reducing risks and improving safety for people living, visiting, and working in the polar regions.

Nickel enrichment during lateritization of ophiolitic ultramafic rocks: A case study from the Kelurahan Pondidrha laterite profile in Sulawesi, Indonesia

The Southeast Asia is one of the most important producers of Ni-laterite deposits in the world, attracting more and more attentions in recent years. However, the lateritization processes as well as the enrichment mechanisms of Ni have not been well constrained. Recently, a Ni-rich laterite profile (KPP) was newly found in the Kelurahan Pondidrha area, Sulawesi island, Indonesia. To better understand the lateritization and Ni enrichment mechanisms, in this study, detailed mineralogical and geochemical analyses were conducted on the KPP. The KPP can be divided into bedrock, saprolitic and lateritic layers from bottom to top. The bedrock is serpentinized harzburgite mainly composed of olivine, serpentine and pyroxene, while the saprolitic layer mainly consists of Fe oxides, olivine, serpentine and pyroxene, and the lateritic layer is dominated by quartz and Fe oxy-hydroxides. Nickel is mainly hosted by serpentine in the bedrock and saprolitic layers, but by oxy-hydroxides in the lateritic layer. From the bedrock to the lateritic layer, whole-rock MgO and CaO contents decrease continuously while TFe2O3 contents increase, with TiO2/Al2O3, Zr/Hf and Pd/Pt ratios keeping stable. Combined with whole-rock pH value deceasing from the bedrock to the weathering products, the above results indicate the decomposition of silicate minerals and the formation of Fe oxides/oxy-hydroxides through hydrolysis during in-situ weathering. This led to the release of Ni and its adsorption by secondary minerals (e.g., Fe oxy-hydroxides in the lateritic layer and serpentine in the saprolitic layer). Nickel shows the highest contents in the saprolitic layer rather than the more weathered lateritic layer, indicating the decoupling between the lateritization and the Ni enrichment degrees. This could be due to the enhanced leaching of Ni from the surface under the tropical rainforest climate and the secondary adsorption in the deeper levels. These Ni enrichment features are commonly observed in the Mg-silicate type laterites, which are distinct from the oxide-type showing highest Ni enrichment in the lateritic layer, indicating that lithology played a critical role in controlling the lateritization and Ni enrichment.

Results of the study of the section of the Takata formation "Yuzhnaya Rassolnaya" in the territory of the Poludovo-Kolchimsky anticlinorium of the Western-Ural folding zone (Krasnovishersky district, Perm territory)

Relevance. Relationship with the Takata formation of diamond reservoir rocks and previously discovered deposits and the presence of prospects for discovering new ones in the zone of the forward folds of the Urals. Aim. To reconstruct the conditions of sedimentation and composition of rocks, the source of the removal of terrigenous rocks of the Takata formation based on the results of studying the "Yuzhnaya Rassolnaya" section. Objects. Terrigenous rocks of the Takata formation in the "Yuzhnaya Rassolnaya" section located in the western part of the alluvial diamond deposit "Yuzhnaya Rassolnaya" in the Krasnovishersky district of the Perm Territory. Methods. Lithofacies analysis, petrographic study of thin sections in transmitted light using crossed nicol methods, determination of the content of rock-forming oxides by X-ray fluorescence on an S8 Tiger (Bruker) spectrometer, analysis of rock-forming elements on glassy disks. Impurity and microimpurity elements (with a content of <5%) were determined using a certified method for defining elements by inductively coupled plasma mass spectrometry according to the method, STO TGU 048-2012. The analysis was performed by ICP-MS on an Agilent 7500cx quadrupole mass spectrometer (Agilent Technologies Inc., USA) using an internal (In Internal standard, Inorganic Ventures, USA) and an external standard SGD-2A (GSO 8670-2005). Results. Lithological-facial, mineralogical, petrographic, lithogeochemical studies of Takata terrigenous deposits were carried out in the "Yuzhnaya Rassolnaya" section in the area of the Polyudovo-Kolchima anticlinorium of the Western Ural folding zone, which made it possible to clarify the sources of matter and sedimentation conditions. The formation of sediments occurred in a transitional sedimentation environment. A transgressive sequence is observed from bottom to top. Terrigenous rocks of the Takata formation include rocks of the first and second sedimentation cycles. They were cut off due to the destruction of primary igneous (acidic and basic compositions) and metamorphic rocks, as well as sedimentary rocks. The totality of the material characteristics of the terrigenous rocks of the Takata formation, taking into account the published data, allowed us to assume that sedimentation of the rocks occurred on the passive continental margin, with the supply of clastic material due to the erosion of internal raised blocks of the foundation of the East European Platform. The activation of the latter occurred in the Emsian time with the manifestation of general lithospheric folding. At the same time, water flows carrying weathering products from the East European Platform eroded sedimentary rocks of the Riphean, Vendian, Ordovician and Silurian, which fragments we observe in small quantities when describing thin sections.