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Natural stone can undergo disaggregation from various causes, including physical actions such as freeze–thaw cycles, temperature and humidity variations, chemical actions such as the solubilization of minerals by organic and inorganic acids, as well as biological actions due to the colonization of organisms that can produce biocorrosion and biomineralization. This research investigates the impact of microclimatic conditions and microbial activity on the physical and chemical integrity of stone heritage, particularly the biodeterioration caused by fungi in the case of a Romanian rock church. Various analytical techniques were employed, including macroscopic and optical microscopy, Raman spectroscopy, X-ray diffraction, and culture-based identification methods, to characterize the mineral composition and microbial contamination of the rock samples. The analyses revealed that the sandstone consists primarily of quartz (over 90%), muscovite (5–10%), and feldspars. The identified fungi included Cladosporium herbarium, Aspergillus niger, and Mortierella hyalina. The SEM images showed fungal hyphae and spores within the kaolinite–illite matrix, indicating significant microbial colonization and its role in rock deterioration. Additionally, microclimatic data collected over a 12-week period highlighted the substantial fluctuations in temperature and relative humidity within the church, which contribute to the physical and chemical weathering of the stone. This study also noted high levels of particulate matter (PM2.5 and PM10) and volatile organic compounds, which can exacerbate microbial growth and stone decay. The comprehensive analysis underscores the need for targeted preservation strategies that consider both microclimatic factors and microbial colonization to effectively conserve stone heritage sites, ensuring their longevity and structural integrity. [ABSTRACT FROM AUTHOR]

The article presents the results of a study of phase transformations in sintered compositions "kaolin-dolomite-alumina". It has been established that the nature of the location of melting isotherms on the triple diagram indicates the spread of neoformation processes into the region of the internal compositions of the triangle and the formation of crystalline phases of the mineral's spinel, corundum, mullite. It is shown that based on alumina-containing waste and kaolin, as well as partially introduced dolomite, it is possible to develop compositions of low-temperature sintering ceramic masses for technical materials. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to the low-temperature synthesis of cobalt-containing diopside pigments based on granulated blast furnace slag and to study the characteristics of the mineral formation processes, changes in the structure and colour indices. Design/methodology/approach: Synthesis of cobalt-containing diopside pigments based was carried out by the directional formation of the mineralogical composition with the introduction of part of the components using granulated blast-furnace slag. Findings: It has been established that the formation of the diopside phase in pigments containing blast-furnace slag as the main component proceeds at low temperatures (1,100°C–1,150 °C). The colour of diopside pigments is formed because of the isomorphic substitution of Si4+ ions for Al3+ ions and Mg2+ ions for Co2+ ions. It is expedient to add CoO in an amount of 0.9 mol (18 Wt.%) into the composition of diopside pigments based on blast-furnace slag to obtain defect-free violet glazes. Practical implications: The developed diopside pigments enable obtaining of high-quality violet glazes for ceramics. The application of the obtained results can significantly reduce the consumption of traditional raw materials in the composition of silicate ceramic pigments, as well as reduce their firing temperature. Originality/value: Calcium, magnesium and silicon oxides are the main components of blast-furnace slag. In addition, granulated blast furnace slag is mainly represented by the glassy phase, which determines its high activity during the firing process. These factors are prerequisites for using the blast-furnace slag as a valuable substitute for chemically pure or natural raw materials in silicate pigments and reducing their firing temperature. [ABSTRACT FROM AUTHOR]

This study investigates the relationship between geological and geotechnical properties of granite formations in the Mudgal region of Karnataka, India. The project includes geological surveys and laboratory testing to better understand the impact of mineralogical composition, texture, and structure on the engineering qualities of these rocks. Natural joints enable massive granite block extraction without wire saw cutting, influencing rock mass gradation. The geological assessments reveal that the study area hosts granite deposits of varying sizes, forms and structural attributes. Joints and natural discontinuities in these formations significantly impact block extraction, affecting their economic viability. Importantly, these granites exhibit limited weathering, rendering them suitable for construction purposes. Geotechnical tests expose correlations between mineral composition, grain size and rock strength. The present study covers petrographical study, Bulk unit weight variations, water absorption, specific gravity and compressive strength of granites. Higher quartz content and smaller grain sizes are found to enhance uniaxial compressive strength. In addition, using regression analysis, a novel empirical relationship is established, providing essential equations for predicting rock qualities based on mineralogical structures. [ABSTRACT FROM AUTHOR]

The relevance of the investigation and creation of a new non-traditional raw material base for wall ceramics for the south of Russia is shown in connection with the decreasing availability of traditional raw materials—loams. Characterizations of the mineral and chemical constituent rock formations of the rocks composing the dumps of coal waste heaps and enrichment plants are given. A serious constraint for the industrial development of coal wastes is the requirement for a great variety of mineral constituents. The chemical and mineralogical compositions and the pre-firing ceramic properties of the waste coal heaps are studied and presented in detail. It is mentioned that fine and thin materials contain coal in an increased amount; due to this, they cannot be considered as the main raw material for the production of wall ceramics. The materials of the medium-sized grain group (2.0–5.0 mm, sifting) can contain up to 2–3% of coal and are most often represented by a mixture of mudstones, siltstones, and sandstones, with the predominance of one or another type of rock. The granulometric composition and the content of large-grained inclusions, molding moisture, plasticity, cohesiveness, desiccation properties, and air shrinkage were studied and determined. It is concluded that the middle group of waste coal heaps in particular are of the greatest interest as a basic raw material for the production of wall ceramic products. [ABSTRACT FROM AUTHOR]

A research investigation was conducted on two variables that are indicative of plastic raw materials based on kaolin vs. interstratified illite-smectite clay and a non-plastic admixture including grog (quartz vs. alumina) during the sintering process of an anorthite porcelain body beginning at 950°C, up to the sintering temperature. A correlation was found between the mineralogical composition and various parameters of the fired bodies. A purely anorthic sintered body can be produced using interstratified illite-smectite clay with quartz as a grog, which has the lowest coefficient of linear thermal expansion in the temperature range of 30°C to 700°C and highest bending strength – modulus of rupture of sintered body. When alumina is present in the raw material mixture, the coefficient of linear thermal expansion is lower due to the absence of the SiO2 phases. Quartz in combination with interstratified illite-smectite clay significantly reduces the sintering temperature through the formation of an amorphous melt up to the sintering temperature. Summary of novel conclusions Utilization of interstratified illite/smectite clay as a raw material Utilization of quartz and alumina as grogs Crystallization of anorthite bodies fired at 950°C Alumina used as a grog lowered the coefficient of linear thermal expansion. Quartz used as a grog lowered the required sintering temperature [ABSTRACT FROM AUTHOR]

ABSTRACTA research investigation was conducted on two variables that are indicative of plastic raw materials based on kaolin vs. interstratified illite-smectite clay and a non-plastic admixture including grog (quartz vs. alumina) during the sintering process of an anorthite porcelain body beginning at 950°C, up to the sintering temperature. A correlation was found between the mineralogical composition and various parameters of the fired bodies. A purely anorthic sintered body can be produced using interstratified illite-smectite clay with quartz as a grog, which has the lowest coefficient of linear thermal expansion in the temperature range of 30°C to 700°C and highest bending strength – modulus of rupture of sintered body. When alumina is present in the raw material mixture, the coefficient of linear thermal expansion is lower due to the absence of the SiO2 phases. Quartz in combination with interstratified illite-smectite clay significantly reduces the sintering temperature through the formation of an amorphous melt up to the sintering temperature.

Environmental pollution by industrial waste, including brown coal mining, is one of the environmental problems of many countries. To improve the ecological situation in the region, it is necessary to recultivate soils contaminated with brown coal waste. The goal of the study was to study the possibility of biorecultivation of soils polluted with brown coal waste from the Lenger deposit located in the south of Kazakhstan. It was found that the inorganic part of the brown coal waste is represented by minerals: Quartz SiO2, Gypsum CaSO4×2H2O, Kaolinite Al2Si2O5(OH)4, Cronstedtite- Fe3((Si0.74 Fe0.26)2O5)(OH)4, Margarite- CaAl2(Si2Al2)O10(OH)2, Muscovite H2KAl3(SiO4)3, Calcite CaCO3, Laumontite CaAl2Si4O12(H2O)2, Lead Aluminium Sulfate Hydroxide Pb0.5Al3(SO4)2(OH)6, with quartz content in samples in the range of 61.5 - 92.9%. The organic part of the waste is 90.0% made up of humic acids and fulvic acids. It has been established that heterotrophic, cellulolytic microflora and micromycetes are represented by the genera Rhodococcus, Bacillus, Pseudomonas, Penicillium; Trichoderma, Dietzia, promising for biorecultivation purposes. The phytocenosis of coal waste dumps is composed of toxicotolerant ruderal plant species of the local flora: Centaurea scabiosa L., Centaurea iberica Trev., Cichorium intybus Linn., Cousinia cyrdariensis Kult., Achilleamille folium L., Thlaspiar vense L., Arctiumto mentosum Mill., Onopórduma cánthium L., Agropyron cristatum L., Phlum pratense L., Erytrigia repens L., Nevski / Agropyron repens L.,Cynodon dactylon L., Capparis spinosa L., Polygonum aviculare L., Dodartia orientalis L., Althaea officinales L., Alhagipseud alhagi (Bieb.)Desv., Peganum harmala L. For biorecultivation of soils contaminated with brown coal waste, an algorithm of work has been developed, including the use of soil blocks with integrated seeds of toxicotolerant plants inoculated with microorganisms.

Abstract Investigating the mineralogical compositions of soils under different geological formations becomes imperative for maximizing agricultural productivity and ensuring the long-term viability of agricultural practices. Therefore, studies were carried out on mineral compositions and diversities of soils developed over the Basement complex rock, Coastal plain sands and Ewekoro formations in Ogun state Nigeria. A total of nine profile pits (three per location) of 2 m × 1 m × 2 m size were dug in all the three locations. Soil samples were collected from the pedogenic horizons of each profile pits in replicates into a well labeled polyethylene bag. Using X-ray diffractometry (XRD) and scanning electron microscopy (SEM) the mineral contents and their relative abundance, elemental compositions and morphologies of the fine sand, coarse silt and clay fractions of the soils at different topographic positions were identified, described and compared. Results obtained from XRD and SEM analyses exhibited similarities. The most abundant elements in the basement complex and Ewekoro pedon were oxygen, carbon and silicon whereas in the coastal plain sand pedon, oxygen, carbon and aluminum were the most abundant element. The presence of mixed-layer illite, mica, kaolinite, quartz, hematite, anatase, goethite, and chlorite at varying degrees was observed in the pedons developed on these geological formations, although kaolinite and quartz dominated the soil matrix. The mineralogical complexity of the pedons followed the order of basement complex > coastal plain sand > Ewekoro formation. Profiles developed on the Ewekoro formation exhibited the highest degree of weathering, as evidenced by their chemical properties and mineralogical compositions. The petrographic evaluation of the three geological formations revealed that all pedons were rich in quartz and exhibited varying degrees of mineral complexity and maturation. The overlapping and distinct characteristics among the geologies indicated different stages of weathering. By using the mineral maturity index, profiles developed over the basement complex rock and the coastal plain sand could be regarded as sub-matured and this could have contributed significantly to the native fertility of these soils and profiles from the Ewekoro formation were the most weathered. The use of Ewekoro formation for agriculture would necessitate significant investments in agro-inputs and sound principles of soil management through integrated soil fertility management.

Purposes: This research focuses on the characterization of phosphate ore, its solid effluents, and nearby contaminated soils in the southwest Tunisia (Gafsa-Metlaoui Basin). It aims also at evaluating the vertical distribution and abundance of critical rare earth elements (REE) in the different materials and their ecological and environmental risks. Materials and methods: The sampled materials went through physical, chemical, and mineralogical characterization which involved XRF, XPS, XRD, and ICP-MS analyses. The REE anomalies and the environmental and ecological indices were calculated. Results and discussions: Results show relatively high concentrations of nine rare REEs, following the sequence La > Ce > Nd > Y > Gd > Eu > Sm > Yb > Tb and trace metal elements (TME) such as Cd, Cr, Mn, Zn, Co, Fe, Sr, Cu, Ni, Pb, Ba that surpass, in some cases, international standards. The vertical distribution of the studied elements within a sediment, tailings, and soil profiles (beyond 20 cm of depth) indicates their likely in-depth migration. TME- and REE-bearing phosphate samples reflect mostly oxic conditions in the southern area with high positive Eu anomalies signifying possible mixing of sources. The environmental assessment indicate no contamination and a moderate enrichment of REEs, except for Eu, which displays significant contamination and extreme enrichment. Whereas, a deficiency of Y has been detected in most of the studied samples except for sludge sample which was also found significantly enriched with REE. Conclusions: There are fundamental similarities between the different studied samples with high carbonate mineral concentrations. Statistical analysis confirmed the spectroscopic fingerprints demonstrating that the different materials share a similar composition. All of these similarities are most likely linked to the impact of mining activities on sediments and soils. Overall, our findings highlight the global effect of ore processing in determining the geochemical and the mineralogical characteristics of the surrounding environments of mines. [ABSTRACT FROM AUTHOR]

«Qarmet» JSC is one of the largest metallurgical enterprises in Kazakhstan, producing steel and other metals. Study of chemical and mineralogical composition of metallurgical slags from this enterprise can be crucial for its process optimization, environmental compliance improvement and efficient waste management. Study of chemical and mineralogical composition of metallurgical slags from «Qarmet» JSC emphasizes importance of researching metal production waste for its efficient recycling. Further research in this area may facilitate development of new waste recycling technologies and improvement of metallurgical production sustainability. During the study of the chemical composition of metallurgical slags of Qarmet JSC, it was found that they contain a significant amount of metal oxides such as iron, manganese, silicon and others. These elements can be potentially useful for reuse in other manufacturing processes or for the production of building materials. In addition, mineralogical analysis has shown that metallurgical slags contain various mineral phases such as silicates, oxides and other compounds. This indicates the complex structure of the slags and the possibility of using them as additives to cement or other building materials. [ABSTRACT FROM AUTHOR]

The study of the chemical and mineralogical composition of the agricultural soils is essential to know its process of formation. and the characteristics associated to the fertility and to the retention of nutrients as foundations for conduct its use and management. With this objective are evaluated Brown sialitic and Vertisols soils representative of the eastern region of Cuba. The technique of X-rays diffraction (DRX) was used for determine the mineralogical and chemistry composition of the predominant soils. Were calculated the oxides SiO2, Al2O3, Fe2O3 and the molecular relations SiO2 / Al2O3, SiO2 / Fe2O3 and SiO2 / R2O3 for characterize the soils. The predominant minerals in the Brown soils were in that order: calcite, quartz, montmorillonite and anortite. In the Vertisols were detected quartz, albite and vermiculite that are very resistant to the meteorism. The vertical distribution of the minerals show a degree of evolution uniform of the parent rocks. The sequence of free oxides (SiO2> Al2O3> Fe2O3) corroborated the sialitic origin of the soil profiles, associated with the predominance of minerals in a relation 2:1. The uniform distribution of the total of elements in all the profiles shows a lithogenic origin. [ABSTRACT FROM AUTHOR]

Purpose. The purpose of this paper is to accomplish a thorough identification of rock types occurring within the Mitrovica region by describing in detail all encountered varieties. The authors aim to determine the discontinuity or continuity of all inter-formational boundaries, crucial for accurate delineation on the ground and complete reflection on a 1:25000 scale map. Additionally, the objective is to identify the nature of contact between rock types and provide a detailed their description. Methods. Field exploration in the Mitrovica region was conducted for several months. Rock identification involved detailed sampling and petrographic analysis, including thin section preparation of magmatic rocks. The method included sample preparation, polarized light source interactions with minerals and observation of optical properties. Key properties observed are birefringence, interference colors, extinction angles, identification and analysis. Findings. Based on the study of stratigraphic units and geological descriptions of mineral outcrop areas, various types of rocks through petrographic microscope preparation, as well as chemical and geochemical analyses, have been differentiated. The Mitrovica area encompasses the following lithostratigraphic units: harzburgite, gabbro, diabase, metasandstone, sandstone, quartzite and grainstone with calcium (Aeolisaccus sp.; Bioclastic grainstone with dacycladal algae and small milliolides; Salpin-goporella sp.). Originality. The originality of the research lies in employing an optical microscope for the precise identification of rocks. Through the re-search carried out in the study area, we obtained a comprehensive petrographic description of mineral composition, texture, and mineralization, facilitating the assessment of the area exploitation potential. Practical implications. The petrographic exploration yielded the conclusion that the Pb-Zn mineralization is present in the study area, which is a sig-nificant finding for the advancement of the mining sector and the local community, provided that environmental preservation measures are upheld and responsible methods of area exploitation are implemented. [ABSTRACT FROM AUTHOR]

Investigating the mineralogical compositions of soils under different geological formations becomes imperative for maximizing agricultural productivity and ensuring the long-term viability of agricultural practices. Therefore, studies were carried out on mineral compositions and diversities of soils developed over the Basement complex rock, Coastal plain sands and Ewekoro formations in Ogun state Nigeria. A total of nine profile pits (three per location) of 2 m × 1 m × 2 m size were dug in all the three locations. Soil samples were collected from the pedogenic horizons of each profile pits in replicates into a well labeled polyethylene bag. Using X-ray diffractometry (XRD) and scanning electron microscopy (SEM) the mineral contents and their relative abundance, elemental compositions and morphologies of the fine sand, coarse silt and clay fractions of the soils at different topographic positions were identified, described and compared. Results obtained from XRD and SEM analyses exhibited similarities. The most abundant elements in the basement complex and Ewekoro pedon were oxygen, carbon and silicon whereas in the coastal plain sand pedon, oxygen, carbon and aluminum were the most abundant element. The presence of mixed-layer illite, mica, kaolinite, quartz, hematite, anatase, goethite, and chlorite at varying degrees was observed in the pedons developed on these geological formations, although kaolinite and quartz dominated the soil matrix. The mineralogical complexity of the pedons followed the order of basement complex > coastal plain sand > Ewekoro formation. Profiles developed on the Ewekoro formation exhibited the highest degree of weathering, as evidenced by their chemical properties and mineralogical compositions. The petrographic evaluation of the three geological formations revealed that all pedons were rich in quartz and exhibited varying degrees of mineral complexity and maturation. The overlapping and distinct characteristics among the geologies indicated different stages of weathering. By using the mineral maturity index, profiles developed over the basement complex rock and the coastal plain sand could be regarded as sub-matured and this could have contributed significantly to the native fertility of these soils and profiles from the Ewekoro formation were the most weathered. The use of Ewekoro formation for agriculture would necessitate significant investments in agro-inputs and sound principles of soil management through integrated soil fertility management. [ABSTRACT FROM AUTHOR]

Tajikistan possesses large reserves of dump tailings characterized by a high gold content. The formation of these dump tailings is associated with the low cost of gold in the past, since rich ores with a gold content above 6–8 g/t were more often involved in processing. At recovery of ≈ 70–75%, tailings with a gold content below 1.8 g/t were disposed of. The paper studies the material composition and carries out an assessment of the degree of refractoriness of the studied dump tailings to leaching. It was established that the main components of tailings are SiO2 and Al2O3. The dump tailings contain 2.4 g/t of gold and 7 g/t of silver. In terms of material composition, the sample of the dump tailings belongs to a readily cyanidable type. Gold finely disseminated in acid-soluble minerals represents 6–6.5%, while minerals insoluble in acids and quartz contain 15% of gold. In addition, the tailing sample contains gold encapsulated in minerals soluble in sulfuric acid. In terms of gold form, the dump tailings are classified as medium refractory to leaching processes. The diagnostic leaching test results for gold showed that the use of thiourea as a lixivant in the further development of the leaching process is promising. Gold recovery by thiourea leaching was 78%. [ABSTRACT FROM AUTHOR]

Throughout history, ceramics have been the most abundant artifacts in archaeological discoveries. Within the Neolithic period in present-day Bulgaria, skilled artisans applied additional materials to decorate their pottery, evolving in composition and application techniques such as painting or incrustation. This study is focused on the investigation of white pigments used in decorating Early and Late Neolithic pottery from Madzherito, Kaloyanovets, and Hadzhidimitrovo—archaeological sites located in the Thracian Valley, Central South Bulgaria, affiliated with the cultural groups of Karanovo I and IV. Thirteen ceramic sherds were investigated through archaeometric techniques, including Fourier-transformed infrared spectroscopy in attenuated total reflection mode (ATR-FTIR) and laser-induced breakdown spectroscopy (LIBS). LIBS data underwent further analysis using principal component analysis (PCA). The results revealed that calcite, enriched with diverse fillers like quartz, clays, feldspars, and metal oxides, was the primary raw material for white decoration throughout the entire period. Talc emerged as an addition to calcite in the paint of two Early Neolithic sherds. The presence of hydroxyapatite and kaolinite in Late Neolithic pottery was also observed. The inclusion of supplementary ingredients in the primary formula for crafting white decorations signifies either the emergence of novel trends in manufacturing techniques or serves as evidence of vessels imported from adjacent territories. [ABSTRACT FROM AUTHOR]

Problematic soils, such as expansive clay-rich soils, need geological and geotechnical assessments before commencing any construction project. The mineralogical composition of the soil plays a crucial role in determining its physical and chemical behavior, ultimately affecting its stability and susceptibility to erosion. This study analyzed the variability of chemical, mineralogical, and morphological attributes of five soils of the Guabirotuba formation. Samples in different areas of Curitiba and the metropolitan region were collected. Chemical composition by X-ray fluorescence spectrometry (XRF), mineralogical composition by X-ray diffraction (XRD), and microstructure by scanning electron microscopy (SEM) were determined. The results showed that the five soils have a similar chemical composition, with silicon dioxide and aluminum oxide being the main constituents. The mineralogical composition varied in all analyzed soils. However, they belong to the same geological formation, and certain conditions, such as weathering, pressure, cation exchange, and climate, may differ in their mineralogy. Four of the five soils analyzed showed low expansion capacity due to kaolinite, characterized by low swelling potential and water adsorption capacity. On the other hand, one of the soils presented expansive potential because it did not have the presence of kaolinite in its mineralogical composition. Finally, the variability of soil characteristics changes from one place to another. Although they have similar chemical compositions, the cation exchange and mineralogical composition contribute to the development of several behaviors that can be useful for decision-making about the destination of said soil. [ABSTRACT FROM AUTHOR]

Uniaxial compressive and Brazilian tensile strengths (UCS and BTS) of rocks are considered important properties in the design of most the geotechnical projects that interact with rock such as slope stability and underground excavation. Indirect tests such as Schmidt hammer hardness (SH) can be used for prediction of UCS and BTS of rocks. The aim of this study is to correlate the UCS and BTS of granitic rocks with SH with an emphasis on influence of petrographic characteristics. For this purpose, 10 different granitic rocks were selected from Iran's quarries and their UCS, BTS, SH and petrographic characteristics including mean mineral grain size (MGS) and mineralogical composition (Quartz/Feldspar ratio) (Qz/Fl) were determined. Using data analysis, correlation between UCS and BTS with SH, MGS and Qz/Fl statistically were investigated using multiple regression analyses. In these analyses, the UCS and BTS were considered to be the dependent variable, which are dependent on the independent variables of the SH, MGS and Qz/Fl. It was found out that there are moderate correlations (R2 = 0.523 to 0.759) between UCS and BTS with SH, whereas there are strong correlations (R2 = 0.868 to 0.955) between UCS and BTS with SH when MGS and Qz/Fl are considered. Finally, it was concluded that the regression equations proposed in this study are in good accuracy for prediction of UCS and BTS, and thus making a rapid assessment from UCS and BTS of granitic rocks. [ABSTRACT FROM AUTHOR]

Evaluation of soil sustainability should take into account chemical and mineralogical changes due to cultivation. Potassium (K) application is a key farming practice that may potentially affect phyllosilicate composition and soil properties. Irrigation is another agent that affects soil composition. This study aims to evaluate the imprints of cultivation on the chemical and mineralogical compositions of lowland soils under semi-arid and Mediterranean climate regimes and to assess them with the natural pedogenesis. The sites examined include two permanent plot experiments with crop rotation, and three single-plant plots. Cultivated, control, and fallow soils were analyzed for their chemical and mineralogical composition. The X-ray diffraction patterns of the clay fraction were decomposed to achieve quantitative detection of changes among the illite–smectite (IS) phases and in kaolinite amounts. In loamy and clayey soils dominated by IS phases, cultivation caused minor changes and diverse behavior of the IS phases. Yet, the K balance was negative under high fertilization levels and higher plant mass production. Fertilization enhanced the natural process of transforming IS into kaolinite and illite in the sandy soil, leading to a positive K balance. This study emphasizes the importance of IS minerals as a dynamic K pool that responds to plant needs. [ABSTRACT FROM AUTHOR]

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The main purpose of this preliminary study is to establish the relationship between the mineralogical and chemical homogeneity of Iron Age pottery vessels from Jneneh in North-Central Jordan and Tell Abu Al-Kharaz in North-West Jordan, as well as to investigate the technological level of production of these vessels found at the two sites. Potsherds were subjected to examination using X-Ray diffraction (XRD), Polarized light microscopy (PLM) and X-Ray fluorescence (XRF), in order to determine the major and minor elements, as well as the mineral content of these potsherds. The results showed high homogeneity in chemical and mineralogical composition in Jneneh potsherds, and this indicates that the mother pottery vessels were manufactured using the same source of raw materials and the manufacturing techniques were not altered with time. Contrarily, high differences in chemical and mineralogical compositions were observed in Tell Abu Al-Kharaz potsherds, leading to the expectation that Tell Abu Al-Kharaz samples were manufactured using different sources of raw materials. The presence of primary Calcite crystals may indicate that the initial firing temperature of all the samples from the two sites did not exceed 800 oC. In addition, in all the samples, Quartz and Chert were crushed before being intentionally added to the clay used for the pottery production. For the purpose of increasing the clay plasticity and decreasing the shrinkage upon drying, bone fragments (Fluorapatite) were added. Some samples from Tell Abu Al-Kharaz indicated that the source of raw materials used for making pottery vessels came from the Upper Cretaceous deposits based on the presence of Foraminifer microfossils, Planulina Nacatochensis. Furthermore, the occasional presence of basalt-forming minerals such as Augite and Plagioclase in some samples from Tell Abu Al-Kharaz indicates that basaltic grinding tools were possibly utilised for preparing the raw materials of pottery vessels. [ABSTRACT FROM AUTHOR]

The characteristics of climatic, lithological and geomorphological conditions of formation of sandy soils of Transbaikalia (Barguzin basin) is given. It has been established that the main soil-forming processes are cryo- and light-humus, accumulative-carbonate and pale-metamorphic. In the soils of deposits, the processes of stratification and abrasion are expressed. Moving sands are not affected by soil formation, but with partial fixation of herbaceous and/or shrub vegetation on them, embryonic underdeveloped soils (layered-eolian, humus psammozems) begin to develop. For the first time, the results of the material composition of the rocks of the Angara-Vitim batholith, soil-forming sand, as well as the composition of minerals of fractions <1.1–5 and >5 µm of cryohumus and light humus soils are presented. It has been determined that the regional features of soil-forming sands are carbonation, alkalinity, and polymineral content, which is inherited from calc-alkaline rocks. The sandy and silty soil fractions have a similar mineralogical composition, which are characterized by a high content of plagioclases and K-feldspars and a low content of quartz. The composition of the silty fraction consists of a mixed-layer phase of illite-smectites interbedded with single chlorite packets, di-trioctadridic illite, ferruginous chlorite, and kaolinite. Modern soil formation is characterized by a low degree of chemical weathering (CWC, CWI, and GM) and weak profile differentiation. A feature of the material composition of sandy soils is an increased content of potassium and sodium. According to the values of total alkalinity, the studied soils are highly alkaline soils. There is a clearly pronounced division of the soil profile according to biological activity. It was revealed that during arable use, sandy soils are potential centers of desertification: in the studied area, all arable lands and fallows located on them are deflated to varying degrees. At the same time, it was found that more than 70% belong to very strongly deflated and strongly deflated types. In such areas, humus soil layers are blown out and carbonate horizons and even soil-forming sands are exposed. The exposed middle horizons and sands do not possess elements of effective fertility. The yield of agricultural crops on such arable lands is very low, the process of natural restoration of vegetation cover on fallow lands is extremely difficult, and deflation ulcers practically do not overgrow. The inhibition of the processes of restoration of natural cenoses is largely due to the alkalinity and carbonation of soil-forming sands. [ABSTRACT FROM AUTHOR]

Natural fertilizers, considered an innovative approach to promoting sustainability and safety in resource management, aim to improve productivity on infertile land. This research focuses on evaluating the physical, chemical, and mineral properties of sediments within Jordan's Tannur reservoir. In the summer of 2021, 34 sediment samples underwent comprehensive analysis, encompassing granulometric and physiochemical characteristics. The study also included the determination of average values for total abundance and available forms of iron, zinc, manganese, nickel, copper, as well as the total forms of nitrogen, phosphorus, and potassium. Chemical analysis unveiled variations in sediment composition, with the lowest concentrations observed near the inlet and the highest concentrations closer to the dam. Four distinct granulometric textural facies clayey, clayey silt, silt, and sand were identified. Mineralogical analysis identified quartz and calcite as primary minerals, alongside others such as orthoclase, kaolinite, illite, smectite, palygorskite, and sporadic vermiculite. Nutrient concentrations within the Tannur sediments align with established global soil ranges, suggesting their potential suitability for use as natural fertilizers or agricultural soil. [ABSTRACT FROM AUTHOR]

The relevance of the investigation and creation of a new non-traditional raw material base for wall ceramics for the south of Russia is shown in connection with the decreasing availability of traditional raw materials—loams. Characterizations of the mineral and chemical constituent rock formations of the rocks composing the dumps of coal waste heaps and enrichment plants are given. A serious constraint for the industrial development of coal wastes is the requirement for a great variety of mineral constituents. The chemical and mineralogical compositions and the pre-firing ceramic properties of the waste coal heaps are studied and presented in detail. It is mentioned that fine and thin materials contain coal in an increased amount; due to this, they cannot be considered as the main raw material for the production of wall ceramics. The materials of the medium-sized grain group (2.0–5.0 mm, sifting) can contain up to 2–3% of coal and are most often represented by a mixture of mudstones, siltstones, and sandstones, with the predominance of one or another type of rock. The granulometric composition and the content of large-grained inclusions, molding moisture, plasticity, cohesiveness, desiccation properties, and air shrinkage were studied and determined. It is concluded that the middle group of waste coal heaps in particular are of the greatest interest as a basic raw material for the production of wall ceramic products.

The results of investigations of the chemical and mineralogical composition and main characteristics are presented to determine the suitability of trachybasalt porphyrite of the Karabulak section of the Gavasai deposit in Uzbekistan for preparing thermal insulation material, in particular mineral fiber. It was found that this new deposit of igneous rock can be used as the main raw material component in the manufacture of basalt fiber products, a widely demanded and modern material in the construction industry. [ABSTRACT FROM AUTHOR]

The development of new materials called geopolymers is described, which at the turn of the nineties brought a new state of the art in material design through the so-called wet process resulting in a specific amorphous state. The classical configuration of glasses prepared by quenching is used for a joint appraisal and judgment. We can use the comparison and description of the known form of organic polymers with the so-called mers-structure. The formation involves a sol–gel polycondensation chemical reaction also known in the case of organic polymers. The formation is described using aluminosilicate oxide in IV-fold coordination with alkaline polysilicates to form polymeric Si–O–Al chains through amorphous to semi- and hypo-crystalline three-dimensional silico-aluminate structures. The revision of structural units and their interconnection is evaluated, and it turns out that the common factor of the multiparty description is the existence of bridging and non-bridging oxygen. The review provides a detailed overview of opinion while reminding that the historical origin of the field falls within the purview of the JTAC journal. [ABSTRACT FROM AUTHOR]

In this study, the characteristics of Okelele clay were investigated using microscopic and spectroscopic techniques for its potential ceramic applications. The raw clay sample was beneficiated by wet sedimentation and separated from impurities through a 63 µm standard sieve. The purified clay sample was characterized using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy interphase with Electron Dispersive X-ray Spectroscopy (SEM/EDX) and Thermogravimetry/Differential Scanning Calorimetry (TGA/DSC) techniques. The XRD pattern revealed the purified clay to be composed of predominantly kaolinite (66.22%) with a substantial amount of quartz (29.76%) and a trace amount of sanidine and cowlesite. The clay morphology exhibits non-spherical particles of various sizes with thermal phase transition stability above 450 ℃. The EDX analysis revealed high alumina and silica content with substantial concentrations of free silica and iron oxide that can improve mechanical properties and withstand thermal conditions. From the results of the chemical characterization, the clay offers potential applications for ceramics, porcelain, pottery production and high-temperature refractories applications. [ABSTRACT FROM AUTHOR]

Colloidal bonds are realized by sol–gel technology. The binder system of the refractory castable belongs to the Al2O3–SiO2 binary diagram. Mullite is the most thermally stable mineral in this system. This work was motivated by an attempt to maximize the mullite content in the NCC binder system, because a high content of mullite is a guarantee of the long service life of refractories. Initially, the mineralogical composition of the pure gel was tested after drying and firing at temperatures between 1000 °C and 1600 °C. The behavior of the gel during drying was described. Subsequently, a method of minimizing gel shrinkage during drying was sought. To this aim, fine fillers (microfillers) of alumina and silica were tested. In particular, the reactivity of the microfillers, the ability of the microfillers to react with the sol to form mullite, and the drying shrinkage of the microfiller-doped gel were evaluated. The study showed that the least suitable source of Al2O3 in terms of its reactivity is tabular corundum, which produces the lowest amount of mullite. The internal structure of the prepared binder system when using different microfillers was described. Based on the results from the second stage of the work, several complete matrixes of the binder system were designed and the degree of their mullitization at different firing temperatures was studied. During this stage, it was shown that the degree of mullitization of the binder system depends mainly on the microsilica content. In the binder system, the maximum mullite content recorded was 76%. The effect of amorphous SiO2 on the bulk density and internal structure of the binder system was also described. [ABSTRACT FROM AUTHOR]

Rock indentation and fragmentation behavior under dynamic and quasi-static loads have significant impacts on the exploration drilling for oil, gas, and geothermal energy. In this study, the mechanical response of rock indentation subjected to dynamic and quasi-static loads was investigated in terms of the interaction between the button and the rock in percussion drilling. The effect of rock type, grain size, and mineralogical composition on rock fragmentation and penetration response was compared, and the cracking characteristics of the rock and crack propagation paths were analyzed. The results show that the damage characteristics of rocks under quasi-static load are similar to those under dynamic load, but the penetration performance under dynamic load is better than that under quasi-static load. The brittleness index can be used to assess the fragmentation performance of different rocks. When the brittleness index of the rock is less than 20, the rock fragmentation performance is particularly sensitive to the brittleness index. The mineral grain size will affect the period of rock failure, when the mineral grain size is less than 900 µm, there is no significant difference in crater depth or volume. The mineralogical composition has a significant effect on the penetration characteristics. When the content of feldspar is more than 5 times that of quartz, the fragmentation performance will not be much different. The relationship between the axial force and the penetration depth follows the power-law relationship, which can be used to describe the dynamic mechanical response of bit and rock in the process of percussion drilling. Highlights: The mechanical response of rock indentation subjected to dynamic and quasi-static loads was investigated and compared. The influence of rock type, grain size, and mineralogical composition on rock fragmentation was evaluated. The rock fragmentation process under quasi-static load can be regarded as a slow motion of rock fragmentation under dynamic load. The relationship between the axial force and the penetration depth in the elastic deformation stage follows a power-law relationship. [ABSTRACT FROM AUTHOR]

The village of Pomarico stands on top of a ridge between the valleys of the Bradano and Basento Rivers (Southern Italy) and is formed by the terms of the Plio-Pleistocene marine regressive cycle of the Bradanic Foredeep. In this area, the presence was observed of post-regressive alluvial facies in non-conformable contact with the underlying formation. This paper, based on an extensive engineering geological survey, reports the find of deposits rather different from those typical of the local stratigraphic series. The micropaleontological analyses indicate that these deposits are referable to Middle-Upper Pleistocene, suggesting a marsh or pond environment subsequent to the filling phases of the sedimentary basin and the following emersion. X-ray diffractometric analyses indicate a mineralogical composition similar to that of the Subapennine Clays, with a predominance of montmorillonite among clay minerals. The higher amount of montmorillonite results in significantly lower shear strength and higher compressibility values, entailing a different general behaviour with respect to natural or human-induced stresses. In order to highlight the relevance of their presence, numerical stability analyses were performed on a slope characterised by the presence of these deposits, also taking into account the seismicity of the area. The results seem to justify the surface creep phenomena and the small shallow landslides that characterise the area. [ABSTRACT FROM AUTHOR]

Small-scale layered intrusions of mafic composition enriched in ilmenite, magnetite and apatite are known in association with the rocks of the anorthositic series of the Korosten pluton. Two Fe-Ti-P deposits have been explored in the most well studied Fedorivka and Stremyhorod intrusions. The geological setting, mineral and chemical composition of mafic intrusions is similar. They are considered to be typical layered intrusions, with gradual accumulation of ore minerals in the upper part of the layered series. This review examines some mineralogical and geochemical features of ores of the Stremyhorod intrusion. Ores are represented by olivine (melano-) gabbro with peridotitic layers. Olivine (Fa46—55), augite, plagioclase (An45—56) and biotite are the main rock-forming minerals. Among the ore minerals, the most common are homogeneous ilmenite (Hem4—6), while magnetite (Uspl2—39) with lamellae's of ilmenite, and apatite occur in a subordinate amount. Apatite is enriched in LREE ((La/Yb)n = 11.9-14.8), has moderate negative Eu-anomalies (0.37-0.45) and increased concentrations of Y and Sr. According to the order of appearance of rock-forming and ore minerals, crystallization proceeded under reducing conditions with early melt saturation in ТіО2, which led to the crystallization of ilmenite, probably even before the appearance of clinopyroxene. The estimation of the melt temperature by plagioclase composition (1060-1100 ºC) and Fo-minal content in olivine (1090-1100 ºC) yielded similar results. The equilibrium conditions were reached at fO2 –8.8 to –9.3, so crystallization of ores of the Stremyhorod intrusion took place at reducing conditions (ΔFMQ = –0.74 - –0.54). Considering the small size of such intrusions, in comparison to the gabbro-anorthosite massifs in the Korosten pluton, as well as ore mineral enrichment and late emplacement relative to the host gabbro-anorthosites, we suppose that these intrusions were formed after separation of residual melts from partly crystallized rocks of the anorthositic series. The composition of such melts (ferrodioritic/jotunitic, basaltic) is still obscure. The Mg# in the equilibrium liquid calculated for ore rocks of the Stremyhorod intrusion is 22-26%, which is slightly higher than that of the Fedorivka intrusion (Mg# 14-22%), and overlaps with jotunites of the Korosten pluton. The process of separation (filter-pressing) of Fe-Ti-P enriched melts and its subsequent migration to the upper level were accompanied by the partial capture of anorthositic material, which affects the geochemical characteristics of the ore gabbroids. [ABSTRACT FROM AUTHOR]

Purpose. The research purpose is to study the forms of gold occurrence in the Takyr graben alluvial-proluvial deposits in order to develop a low-waste resource-saving processing technology. Methods. At the first stage, in the course of field studies, the geological structure of the site is specified, samples are taken for mineralogical-technological analysis, which includes the following procedures: studying granulometric and mineral composition of detrital material; fractional gravitational beneficiation of the source material; fractional beneficiation of material pre-processed in the autogenous mill (AG mill); studying free (native) and bound gold in beneficiation products, their quantitative assessment. The samples are processed under the three-stage scheme using an autogenous mill for sample preparation. Findings. For the first time, the geological structure of the site has been specified with the identification of the deposits in the Turangi and Tuzkabak suites within its boundaries, as well as granulometric and petrographic composition of gold-bearing deposits, and the specifics of gold bearing. The detrital material, represented by quartz with a sharply subordinate amount of quartzite, quartz diorites and jasperoids, is practically identical in all fractions. Originality. For the first time, various types of gold mineralization have been identified in placer sands: clastogenic, newlyformed hypergene, newly-formed hydrothermal and residual. Fractional beneficiation makes it possible to estimate the gold content in each fraction and gravitational beneficiation products, as well as the ratio of free and bound native gold in different fractions. The largest amount of free native gold has been revealed in fractions of -0.25 + 0.1 mm (60%) and -0.074 + 0.044 mm (~40%). Gold is high-grade (96.5%) with an admixture of silver and iron. Together with gold, ilmenite, zircon, scheelite, native bismuth, as well as barite, galena, sphalerite, and dolomite have been identified. Practical implications. The research results make it possible to reassess the prospects of similar objects, to adjust the scheme and methodology for processing stream-sediment samples, to solve the issues of productive sand processing technology, as well as to improve the efficiency of geological exploration and eliminate the "underestimation" of gold deposits. The results obtained can be recommended for implementation by both domestic and foreign organizations specializing in the exploration and mining of gold deposits. [ABSTRACT FROM AUTHOR]

The relevance of the work is related to the solution of environmental problems while reducing the use of natural resources and the search for ways to create alternative binders with specific properties. The aim of the work was to solve the problem of resource saving by justifying of waste blast-furnace slags as slag-alkali binders (SAB). Waste blast-furnace slags of PJSC Dneprovskiy Metallurgical Plant, Zaporizhstal, Mariupol Metallurgical Plant, Alchevsk Iron and Steel Works and waste and granulated blast-furnace slag of ArcelorMittal Kryvyi Rig were studied. The slags were dispersed to a specific surface area of 2700-4950 cm²/g. For mixing, water and 20 % NaOH solution were used. The strength of the SAB samples was determined on a P-5 press. The mineralogical composition of the SAB was determined by X-ray phase analysis. Slag fractions were selected that meet the criteria for practical utilization: the ratio of oxides of the main elements, compliance with the requirements of the modular classification and the values of the quality and saturation coefficients. The interaction of slag minerals with mixing agents is confirmed by a change in the mineralogical composition of the SAB compared to the initial composition of slags. New formations are represented by Ca and Mg aluminosilicates, carbonate compounds and sodium-containing phases, which are the products of hydration hardening. The different nature of the SAB hardening products indicates the simultaneous implementation of the contact-condensation and hydration mechanisms of the process. In terms of mineralogical composition, SABs based on waste blast-furnace slags occupy an intermediate position between clinker cements and SABs based on granulated blast-furnace slags. Special properties of SAB are predicted: the duration of strength increase in time; compaction and strengthening of the structure as a result of the formation of carbonate phases; resistance to sulfate corrosion; heat resistance. [ABSTRACT FROM AUTHOR]

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Using a combination of field observations, textural analysis, scanning electron microscopy (SEM), mineralogical X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and thin-section analysis, the hydrocarbon and paleoenvironmental characteristics of the Cretaceous sandstones of the southern Bida Basin, Nigeria, were evaluated. SEM data were used to display the mineral morphology, degree of cementation and presence of clay minerals on the grain surfaces and their pores on both sandstones of the Patti and Lokoja formations. The lithofacies analyses revealed three distinct facies associations. The XRD data showed that for the Lokoja and Patti sandstone reservoirs contained quartz from 49 to 67% and 43–68%, respectively. The XRF data also showed that both formations' sandstone reservoirs have a high percentage of silicon and low aluminum content. The grain size study showed that the Lokoja sandstone reservoirs include medium-coarse sandstone (−0.63 to 1.30 ф) that are poorly-moderately sorted (0.72–1.82 ф). In contrast, the Patti Formation is primarily made up of fine-medium sandstones at investigated outcrops, which typically display reasonably good to poor sorting (0.70–2.53 ф). The skewness of the sandstone reservoirs ranged from fine to coarse, and their kurtosis ranged from very platykurtic to leptokurtic. The research area's predominant depositional environments include shoreface/foreshore, estuary mudflat, and estuarine delta with fluvial interference, according to an analysis that combined sedimentary facies and textural data. This demonstrates that the sandstones from the two units have moderate quality prospective hydrocarbon reservoirs based on their physical and chemical characteristics.

The results of investigations of the chemico-mineralogical and fractional compositions as well as physicochemical properties of glauconite sandstones of the Changi deposit are presented. Enrichment methods were selected and thermal activation was conducted. The coloring properties, hiding power, and oil absorption of the obtained brown and green pigments were investigated. It was been determined that this glauconite sandstone can be used as a raw material for the production of coloring pigments in the building materials industry and the manufacture of ceramic glazes at manufacturing enterprises in Uzbekistan. [ABSTRACT FROM AUTHOR]

The effect of the addition of silica fume, calcium carbonate or silicon carbide in an alternative cementitious matrix based on anhydrite and blast furnace slag is reported in this paper. The addition of any of these materials improved the compressive strength of the systems, with the one containing 5% silica fume exceeding 22 MPa at 28 days and 26 MPa at 360 days of curing, showing the best compressive strength over the test period. Increasing the addition of silica fume resulted in a decrease in compressive strength because silica fume interferes with the hydration reaction of anhydrite. The systems with silica fume showed lower expansions, of 0.06%, compared to 0.11% for the other systems, because the pozzolanic reaction of the silica fume to form calcium silicate hydrate densifies the matrix preventing the ettringite from finding a place to nucleate. The hydration products were identified as gypsum and ettringite, in addition to calcium silicate hydrate, which covered the gypsum crystals forming an intermixed structure between the two phases. Despite the appearance of ettringite, no cracking or spalling was observed, even after 360 days of curing. [ABSTRACT FROM AUTHOR]

Modern cements are complex materials with well-defined compositions that reach to high and consistent results. Automated techniques such as Rietveld analysis lead to provide an understanding of the composition and polymorphism of cement phases that could lead to control of the clinkering conditions to optimize characteristics and consequently quality product. For the characterization of cements used in the construction sector, Rietveld method has significant benefits over other analytical techniques. The precise information about phase assemblage and polymorphism lets monitoring the hydration behavior of binder materials. The objective of this paper is to report the quantitative Rietveld phase analyzes for three industrial clinkers, to review the most recent quantitative X-ray powder diffraction studies on anhydrous cement and to discuss the influence of the different parameters elaborated in the Rietveld method. [ABSTRACT FROM AUTHOR]

Bauxite, which is the main raw material that aluminium is extracted from was discovered in Africa in the early 1900s. Currently, the production and export capacities of the African Bauxite ore are about a third of the World's total capacity. However, the processes leading to the final finished product of; surface mining of the ore, refining ore into alumina and finally extracting the pure aluminium metal in high energy consuming smelters that employ the Hall-Héroult electrolysis process; seldom take place inside Africa. The main goal of this work is to analyse the mineralogical and geochemical characteristics of bauxite deposits from some prominent bauxite producing and exporting countries of Africa in order to fashion out if a trend exist for the type of source rocks. Judging from the data obtained, gibbsite is found to be the main aluminium oxide in all the bauxite deposits with slight occurrence of boehmite in 3 out of the 13 deposits, while goethite is the main oxyhydroxide iron mineral. The compiled results of the various investigations highlighted the fact that the deposits are of diverse qualities with respect to world standard of major element content of bauxite; with average percentage concentration in the ranges as: Al2O3 (43.73–61.25), Fe2O3 (1.55–34.25), SiO2 (0.42–10.84); except two of the deposits with alumina content less than 40%. With evaluated silica moduli less than 8 for only two (2) of the deposits (4.76 and 6.94), the rest have higher moduli that ranges between (14.49 and 75.45). The higher percentage of iron oxide content (>20) in six (6) out of the 13 ore deposits, allowed the deposits to be grouped into three (3) categories of grades; high alumina ore, ferruginous ore, siliceous ore and combination of each. Source rock of the deposits were determined through geochemical and petrographic considerations of laterisation products of the rocks through evaluation of the weathering indices of; Chemical Index of Alteration which was in the range (97.16–99.98) while the Ruxton ratio ranged between (0.0133–0.2100); signifying the parent rock underwent intensive weathering process. This is indicative of the source rocks of the Bauxite deposits being either (i) anorthositic, (ii) argillite and dolerite, (iii) granulite and feldspathic gneiss, and/or, (iv) mafic-basaltic andesite igneous. Awareness of new and yet-to-commence emerging bauxite producing African countries was created, by highlighting the economic impact those respective countries will experience when that mining sector is developed for the aluminum industry at home and world at large.

Evaluation of soil sustainability should take into account chemical and mineralogical changes due to cultivation. Potassium (K) application is a key farming practice that may potentially affect phyllosilicate composition and soil properties. Irrigation is another agent that affects soil composition. This study aims to evaluate the imprints of cultivation on the chemical and mineralogical compositions of lowland soils under semi-arid and Mediterranean climate regimes and to assess them with the natural pedogenesis. The sites examined include two permanent plot experiments with crop rotation, and three single-plant plots. Cultivated, control, and fallow soils were analyzed for their chemical and mineralogical composition. The X-ray diffraction patterns of the clay fraction were decomposed to achieve quantitative detection of changes among the illite–smectite (IS) phases and in kaolinite amounts. In loamy and clayey soils dominated by IS phases, cultivation caused minor changes and diverse behavior of the IS phases. Yet, the K balance was negative under high fertilization levels and higher plant mass production. Fertilization enhanced the natural process of transforming IS into kaolinite and illite in the sandy soil, leading to a positive K balance. This study emphasizes the importance of IS minerals as a dynamic K pool that responds to plant needs.

Using a combination of field observations, textural analysis, scanning electron microscopy (SEM), mineralogical X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and thin-section analysis, the hydrocarbon and paleoenvironmental characteristics of the Cretaceous sandstones of the southern Bida Basin, Nigeria, were evaluated. SEM data were used to display the mineral morphology, degree of cementation and presence of clay minerals on the grain surfaces and their pores on both sandstones of the Patti and Lokoja formations. The lithofacies analyses revealed three distinct facies associations. The XRD data showed that for the Lokoja and Patti sandstone reservoirs contained quartz from 49 to 67% and 43-68%, respectively. The XRF data also showed that both formations' sandstone reservoirs have a high percentage of silicon and low aluminum content. The grain size study showed that the Lokoja sandstone reservoirs include medium-coarse sandstone (- 0.63 to 1.30Ф) that are poorly-moderately sorted (0.72-1.82 Ф). In contrast, the Patti Formation is primarily made up of fine-medium sandstones at investigated outcrops, which typically display reasonably good to poor sorting (0.70-2.53 Ф). The skewness of the sandstone reservoirs ranged from fine to coarse, and their kurtosis ranged from very platykurtic to leptokurtic. The research area's predominant depositional environments include shoreface/foreshore, estuary mudflat, and estuarine delta with fluvial interference, according to an analysis that combined sedimentary facies and textural data. This demonstrates that the sandstones from the two units have moderate quality prospective hydrocarbon reservoirs based on their physical and chemical characteristics. [ABSTRACT FROM AUTHOR]

Egyptian Eastern Desert is rich in many areas that contain granites masses throughout the geological era; some of them show good characteristics of the rock hardness, durability, density and mineralogy. This current research aims to utilize three main types of granite aggregates based on their mineralogical composition and Alkali reactivity with cement during concrete production. The studied granite aggregate can be also classified into red younger granite aggregate, white older granite aggregate and grey older granite aggregate. Evaluating these granite rocks as aggregate used in concrete mixture is interesting by produced three mixes using the three studied granite aggregate symbolized (Red GA), (White GA) and (Grey GA), tested mechanically to give a more detailed for the obtained results to be not restricted for only studied granite aggregate criteria but also to follow the actual reaction of this studied granite aggregate with cement. It was obtained that all studied granite aggregates within acceptable limits of concrete aggregate by following Egyptian code (ECP-203) although their variation on its mineralogical composition. Some reflections produced from change in mineralogical composition between the three studied granite aggregates exhibited by relative regression in the average physico-mechanical values for both (White and Grey GA) than (Red GA). On the other hand, slight reactive for (Red GA) than others at the age of 28 day. In addition, all produced (Red GA), (White GA) and (Grey GA) mixes were acceptable mechanically with limits of (ECP-203) giving benefit for using all of the studied granite aggregate after their detailed study involving its mineralogical composition and alkali aggregate reactivity (AAR). [ABSTRACT FROM AUTHOR]

Soil plays an important role in the accumulation and transport of potentially toxic elements (PTEs), from surface into aquifer. PTEs can get to the environment naturally, but also from different kinds of contamination sources. In this study, a soil profile located in the vicinity of well field Petruševec, one of the most important well fields related to the public water supply of the City of Zagreb, was analyzed. The main aim of this study was to determine soil properties which can influence retention/mobilization of Ni and Cr in alluvial soil, as well as to define their origin in the investigated soil profile. Results suggest that Cr is geogenic, while Ni is probably of dominantly anthropogenic origin. Observed concentrations, enrichment factors and Igeo values showed no enrichment for Cr, while for Ni, they showed minor to very severe enrichment, i.e., that in some soil horizons, moderate to strong pollution exists. Evaluation of wind directions and location of possible contamination sources that prevail in the study area suggest that Ni can come by aerodeposition from different sources. Results showed that mineral composition can have important influence on retention of analyzed PTEs. Soil horizons, which have very high concentrations of Ni, in general have higher proportion of clay minerals, especially chlorites, as well as Fe oxyhydroxides which can act as an adsorption phase for the investigated PTEs. Results suggest that more detailed research about the investigated PTEs presents a necessity if measures for soil and groundwater protection want to be effectively implemented. [ABSTRACT FROM AUTHOR]

Purpose: The main aim of this study was to investigate factors influencing the long-term distribution of 137Cs activity concentrations in the bottom sediments of the dam lake, Koronowo Reservoir, 32 years after the Chernobyl nuclear power plant accident. For this purpose, selected properties of the collected sediment samples, such as grain size, mineralogical composition, and organic matter (OM) content, were investigated. Materials and methods: The samples of lake sediments were collected with a Kayak-type gravity corer. The spatial and vertical distributions of 137Cs and 40K activity concentrations in the bottom sediments were investigated based on gamma spectrometry measurements. The particle size distribution of surface lake sediments was determined using a laser particle size analyzer. SEM and XRD were used for the mineralogical analysis of the collected sediment samples. Additionally, the content of organic matter was examined in all samples using an elemental analyzer. Results: The 137Cs content was significantly elevated in the case of fine-grained (< 63 µm) surface lake sediments (classified as silts, which are deposited in the profundal zone of Koronowo Lake) and ranged from 12.5 ± 4.1 to 29.2 ± 4.0 Bq kg−1. It was found that the increased concentration of 137Cs activity is more closely related to the content of the silt fraction (2–63 µm) than to the clay fraction (< 2 µm) in the collected surface lake sediments. The content of clay minerals also showed a significant positive correlation with 137Cs activity concentration in the surface lake sediments of Koronowo Lake. A similar relationship was noticed for the OM content, but it may be suspected that it is the result of radiocesium-bearing particle accumulation in OM-rich sediments. Conclusion: The most important factor influencing the spatial distribution of 137Cs activity concentrations in the surface lake sediments of Koronowo Lake, apart from the bottom morphology and grain size of sediments, is the content of clay minerals. Moreover, the increased detrital inflow to the lake after the construction of the dam could have probably affected the vertical distribution of 137Cs activity concentrations in the bottom sediments, as evidenced by, e.g., the measurements of 40K activity concentration. [ABSTRACT FROM AUTHOR]

The heterogeneous mineralogical compositions of fault gouges, formed during fault evolution, influence frictional properties and slip behaviour. While the influence of individual mineral phases on friction has been extensively studied, the impact of varying systematically mineral phases in gouge mixtures on macroscopic frictional behaviour remains unclear. Thus, we performed 34 frictional experiments on fault gouges composed of three representative mineral phases: muscovite (platy phyllosilicate), quartz (granular silicate) and calcite (granular carbonate), known for their markedly distinct frictional properties. Using a biaxial rock deformation apparatus (BRAVA), we performed tests on fault gouges with grain sizes <125 μm under normal stresses of 50–100 MPa, at room temperature and water-saturated conditions. Our data indicate that the mineralogical composition of fault gouges significantly affects frictional strength, healing, and stability with a non-trivial pattern. Increasing the muscovite content leads to a decrease in frictional strength, from 0.62 for pure calcite and 0.56 for pure quartz to 0.33 of pure muscovite, along with reduced frictional healing and a velocity-strengthening behaviour. This weakening is promoted by a transition from localized deformation along discrete shear planes in granular-rich fault gouges to distributed deformation within the entire gouge layer with increasing muscovite content. At fixed muscovite content, frictional properties depend on the dominant granular phase. Calcite-dominated mixtures exhibit more marked frictional weakening rather than quartz-dominated ones, suggesting a non-linear mixing law between friction coefficient and muscovite content. This different trend is likely due to favourable conditions for fluid-assisted pressure-solution of calcite and foliation development, unlike quartz. When only the granular phases are mixed, we observe complex behaviour with the indentation of quartz into calcite, resulting in higher values of healing rates than those of pure end-member mixtures. Our findings provide robust insights into microphysical processes strongly dependent on the complex mineralogical compositions usually observed along natural faults. • Systematic quantification of frictional properties in ternary mixtures composed of quartz, calcite, and muscovite minerals. • Frictional strength, healing, and rate-dependence result from the non-linear interaction of mechanically distinct phases. • Grain-scale deformation mechanisms underlying macroscopic behaviour are revealed by a comprehensive microstructural analysis. [ABSTRACT FROM AUTHOR]

The pore structure characteristics of shales are controlled by their mineral and organic matter compositions. However, the contributions of different components to the pore structure characteristics of lacustrine shales remain poorly understood. In this study, fifteen Chang 7 Member shales of the Yanchang Formation, Ordos Basin, were investigated through total organic carbon (TOC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and low-pressure N2 and CO2 adsorption analyses to study the control of shale composition on the pore structure characteristics of lacustrine shales. The results show that the average TOC content of the Chang 7 Member shales is 9.63 wt.%. XRD analysis shows that minerals in the Chang 7 Member shales consist of quartz, feldspars, clay minerals, and pyrite. The clay minerals were dominated by illite, chlorite, and interstratified illite/smectite. The mesopore characteristics of the Chang 7 Member shales and micropore characteristics of organic-lean shales are mainly controlled by clay minerals, whereas the micropore characteristics of organic-rich samples are controlled by both clay minerals and organic matter. SEM observations show that the phyllosilicate framework pores are the main pore type in the Chang 7 Member shales. The results of this study provide important insights into compositional control on the pore structure characteristics of lacustrine shales. [ABSTRACT FROM AUTHOR]