Clay Minerals - Science topic

Desert varnish, or rock varnish, is a thin reddish-black microlayer that covers rocks and consists mainly of clay minerals, as well as oxides of iron and manganese. In this paper, both terms-desert and rock varnish-are used interchangeably. Rock varnish has been an object of study and interest for more than two centuries. As it develops mainly in a...

Seismic anisotropy of the Earth's mantle has been mostly attributed to crystallographic preferred orientation (CPO) generated during subduction and convection of an anhydrous mantle. But some hydrous phases are also stable at mantle conditions. Here we present results from diamond‐anvil cell deformation experiments at high pressure and temperature...

The freezing of capillary and adsorbed water exerts a substantial influence on rock seepage and frost heave. In order to investigate the influence of pore structure and water–mineral interactions on water freezing of sandstones, x-ray diffraction, nitrogen gas adsorption (N2GA), and nuclear magnetic resonance (NMR) at various temperatures are condu...

The water pycnometer method, which has been widely used for measuring soil particle density (ρs), is subject to errors due to interactions between water molecules and clay minerals. In this study, we evaluated the influences of soil mineralogy and organic matter content on ρs and quantified the measurement errors of the water pycnometer by comparin...

The main aim of this study was to produce acid-activated bleaching earth from bentonite clay for edible oil bleaching, which is a clay mineral that can be used in its natural or acid-activated states to clarify and reduce the colour intensity of fats and edible oil. This study was conducted in two stages. The first involved the characterization of...

To investigate the influence of microstructural heterogeneity on rock deformation and failure mechanisms, this study first analyzes the mineral composition of mudstone and obtains its mechanical parameters through laboratory testing. Subsequently, establishing a particle flow code-grain based model (PFC-GBM) to simulate the microstructure of mudsto...

Purpose Biochar’s effectiveness in enhancing soil potassium availability has been well established in short-term pot experiments, but its long-term impact remains unclear. This study evaluates the effects of continuous biochar application on potassium supply by analyzing clay mineral composition and potassium adsorption sites in field conditions....

Investigations into the complex pore–throat structures (PTS) of tight sandstone reservoirs are vital for optimizing waterflooding strategies. In this study, 13 cores from the Dingbian area of the Ordos Basin were examined using casting thin sections, X-ray diffraction, high-pressure mercury injection (HPMI), and nuclear magnetic resonance (NMR). Th...

Chitosan + bentonite modified composite was synthesized to analyse its removal efficiency for Cu(II) metal ions. FTIR analysis done for chitosan, bentonite and the prepared biocomposite of chitosan + bentonite gave detailed information about the active functional group present on the site of adsorbent. SEM-EDS micro-graphs reflected the distributio...

Objective: The objective of this paper was to conduct the physical, chemical, and mineralogical characterization of soils developed over the Jandaíra Formation, located in the municipality of Mossoró (RN), Brazil. Theoretical Framework: The Potiguar Sedimentary Basin, in the Northeast region of Brazil, includes formations with significant potential...

In this study, a mineral-organic composite adsorbent (Montm@GHBC) was synthesized using Montmorillonite clay and biochar derived from Gossypium hirsutum L., the world's most widely cultivated cotton species. The composite was prepared via an impregnation-carbonization method, and its adsorptive properties were evaluated for the removal of Malachite...

Low-salinity waterflooding (LSWF) is an effective enhanced oil recovery (EOR) method, where injecting low-salinity brine disturbs the reservoir’s chemical balance to mobilize residual oil. However, clay minerals, abundant in sandstone reservoirs, pose challenges due to their tendency to swell and migrate, leading to permeability reduction and poten...

The natural clay mineral vermiculite has been overlooked as a promising candidate for scalable production of large aspect ratio 2D wide band-gap semiconductors. We combine here efficient methods for vermiculite delamination, which provides single nanosheets of ~1 nm thickness. It is demonstrated by experiments and simulations that delaminated vermi...

One of the most challenging problems in paleoclimate research is how orbital cyclicities forced Earth's climate variations during the late Quaternary. To address this issue, we investigated the differences in silicate weathering, a sensitive climate indicator, at different latitudes on orbital timescales by examining geochemical and clay mineral da...

To investigate dairy manure urea fertilizer interactions in cropped soils of the semiarid‐West, we fall‐applied and incorporated (0–0.3 m) soil urea‐N (FertN) rates of 10 (N0), 45 (N1), and 80 mg N kg⁻¹ (N2), co‐applied with either no manure or 86 Mg ha⁻¹ (dry wt.) stockpiled dairy manure. Soil net N mineralization, inorganic N (InorgN*), and water...

The clay-bearing skarn is a typical swelling rock that exhibits volumetric swelling and mechanical property degradation upon water absorption, causing serious damage to rock engineering. To investigate the swelling behavior of skarn, a new experimental apparatus has been developed to simultaneously measure swelling strain and water content during t...

Kepahiang Regency, located in an active fault zone, has great geothermal potential with an estimated capacity of up to 154 MW(e), making it a strategic renewable energy source to be developed. This research discusses the geothermal potential in the Kabawetan area, Kepahiang, Bengkulu. The main objective of this research is to evaluate the potential...

The Orobic Thrust is a prominent regional-scale fault zone extending over 80 km, recognized as one of the largest structures in the retro-belt of the European Alps. It represents a significant tectonic boundary where the Variscan basement is thrust southward over the Upper Carboniferous to Lower Triassic volcano-sedimentary cover of the Southalpine...

The Carboniferous–Permian strata in the Daning–Jixian Block, located on the eastern edge of the Ordos Basin, host multiple sets of tight gas reservoirs. However, systematic research on the characteristics and gas production differences of multilayer tight sandstone gas-bearing systems remains limited. Based on geochemical signatures, reservoir pres...

Arsenic contamination in water remains a critical global challenge, particularly in rural and resource-limited regions. Clays have been widely studied as cost-effective and efficient adsorbents for arsenic removal. This systematic review provides a comprehensive analysis of the application of clays in arsenic adsorption, focusing on clay types, ope...

The Tengger Desert (TGD) and the Ulan Buh Desert (UBD) are major sources of Asian dust. To support accurate investigations into environmental and climatic impacts of dust from these deserts, we analyzed over sixty thousand individual dust particles, generated by sandblasting from their primary surface types: Gobi soils and sand dunes. TGD particles...

This study investigates the adsorption properties of arsenic (As(V)) from aqueous solutions using natural clay (NAC) and heat-treated natural clay (HTNAC), highlighting its novelty and significance as a sustainable approach to arsenic removal. The unique adsorption behaviors of the clays, enhanced by heat treatment, provide valuable insights into t...

Landslides triggered by extreme rainfall often cause severe casualties and property loss. A recent case in Wuping County, southeastern China, exemplifes this. Between May 22 and 27, 2022, cumulative rainfall exceeded 250 mm, with a peak hourly intensity of 61.2 mm/h, triggering 867 shallow landslides averaging 1.3 m in thickness. The spatial dist...

Understanding the effects of cryogenic environment on the mechanical properties of sandstone is essential for utilizing abandoned wells and tunnels as potential host rocks for liquified natural gas (LNG) storage, ensuring their safety and stability. To investigate the mechanical properties of sandstones with different porosities and mineral composi...

Plasticity properties of fine-grained soils in the form of Atterberg limits are very important inferential properties used for classification and preliminary qualitative assessment of their suitability for any geotechnical engineering applications. Through extensive research, it is well understood that clay mineralogy and soil structure are the mai...

Clay minerals obstruct the gas production channels of coalbed methane wells, leading to reduced production and severely limiting overall gas extraction. Acid corrosion-based plugging is an effective technique for efficiently cleaning clay minerals. This study investigates the infiltration mechanism and wetting effects of a compound acid unplugging...

Arsenic (As) contamination in groundwater is a serious environmental and public health issue, particularly in regions where groundwater is a primary source of drinking water. Many Asian countries, particularly Bangladesh, India and parts of Southeast Asia are adversely affected with As contaminated aquifers. The present study thus aims to explore t...

Alkyl levulinates are bio-based chemicals with great potential for application in the fields of energy and fine chemical synthesis. They are synthesized via the esterification of levulinic acid with the corresponding alkyl alcohols over Brønsted acid catalysts. Here, three types of commercially available, low-cost, and environmentally friendly laye...

Two novel and unique adsorptive materials, one (Fluorolock®) from clay mineral sepiolite coated with the cationic polymer polydiallyldimethylammionium chloride (pDADMAC) and the other (Intraplex®) from colloidal activated carbon were specially developed for the in situ remediation of per- and polyfluoroalkyl substances (PFAS) in the saturated zone....

Arctic fjords are ideal sites for studying the recent sedimentary process that affects high-latitude coastal ecosystems. High latitude Raudfjord, Magdalenefjord, and St. Jonsfjord from the west Spitsbergen, Svalbard have been investigated to assess the source and distribution of clay minerals, weathering processes, and geochemistry of major element...

The transfer of radiocaesium (¹³⁷Cs) from soil to crops is the main long-term radiation risk after nuclear accidents. The prevailing concept is that ¹³⁷Cs sorption in soil – and, hence, its bioavailability – is controlled by soil clay content (0–2 µm). This study tested this assumption using 24 soils collected worldwide. The radiocaesium intercepti...

Since several decades, the groundwater, hosted in the Plio-Quaternary aquifer, has been the primary resource for drinking and irrigation purpose in Zamrane region (Haouz basin, Morocco). Thus, the main purpose of this study is to evaluate the groundwater quality deterioration in Zamrane region. A total of 82 groundwater samples collected in April 2...

Novel geothermal power generation systems are being developed that use supercritical CO2 as the heat transfer medium. In this technology, some CO2 injected into the underground reacts with surrounding water and rocks to form secondary minerals, such as carbonate minerals and clay minerals; however, the reaction mechanism in the vicinity of the inje...

The expansion of clay minerals in water significantly contributes to mudstone softening. This study investigates how key clay minerals influence mudstone’s strength and energy dissipation during failure. X-ray diffraction was used to analyze changes in micro-mineral composition before and after water saturation. The crack volume strain inflection p...

The time-dependent deformation control of weakly cemented soft rock in deep underground engineering is a critical scientific issue that directly affects the long-term stability of roadways. Traditional Nishihsara models encounter limitations in accurately capturing the weakening effects of material parameters during rock creep failure and in descri...

This review explored the potential of kaolinite clay as a green and sustainable raw material for the production of zeolites. Clay is a naturally abundant and inexpensive mineral, with unique properties that make it an ideal precursor for zeolite synthesis. The review discussed the properties and applications of clay minerals, as well as the prepara...

The duration of water immersion significantly affects the mechanical response of rock materials. This study investigated the weakly cemented sandstone from the Wulagen Open-pit Mine to examine how varying immersion times affected the mineral composition, micro-porous structure, and macro-mechanical properties of the sandstone. The current study aim...

Plain Language Summary We track the morphology, size, and within‐scene density of post‐depositional (diagenetic) features on Mount Sharp in Gale crater, as a way to characterize subsurface fluid flow. To study these changes, we analyzed images taken by Curiosity's Mars Hand Lens Imager (MAHLI) and Mast Camera (Mastcam). MAHLI provided views of rock...

As emerging contaminants, rare earth elements (REEs) have undergone significant anthropogenic enrichment in aquatic systems. This study investigates the REE concentrations, major metal elements, and grain size in surface sediments from the East Tiaoxi (ETX) River in eastern China, a small urban river subjected to substantial anthropogenic influence...

The Pliensbachian-Toarcian boundary and early Toarcian events indicate significant environmental and oceanographic instabilities attributed to the emplacement of the Karoo-Ferrar large igneous province and subsequent greenhouse gas emissions. These geologic processes influenced carbon cycle perturbations and global warming, consistent with phases o...

Some agricultural soils are contaminated with potentially toxic elements (PTEs) like Cd, necessitating remediation to safeguard the food chain. However, a research gap exists regarding the combined use of biochar and clay minerals, particularly phosphoric acid-modified biochar and bentonite (an abundant and cost-effectiveness mineral in Iran) for C...

The presence of fossilised fungi within deep crustal rock formations has been established based on fossil evidence from 400 Ma continental crust and 81 Ma oceanic basaltic crust. Moreover, the Palaeoproterozoic Ongeluk Formation contains putative fungal remains reaching 2.4 Ga. The resulting gap of 2 billion years raises questions regarding the his...

This study examines the impact of shale volume (Vsh) and clay mineral distribution on the petrophysical properties and reservoir quality of the Matulla Formation in the Gulf of Suez, a critical factor in global hydrocarbon exploration and production. Understanding how shale affects porosity, permeability, and fluid saturation enhances reservoir cha...

The influence of clay mineral content on biogenic gas production in coal seams remains insufficiently understood. This study systematically investigated the mechanisms by which clay minerals affect biogas production in low- and medium-rank coals by integrating simulated biogas production experiments with multidimensional analytical techniques, incl...

A high-resolution biostratigraphic analysis based on planktonic foraminifera at the Bade section (Dohuk area, northwest Iraq) across the K-Pg boundary shows an uninterrupted pelagic succession. The succession consists of the uppermost part of the bluish marlstone of the Shiranish Formation (Maastrichtian), and the buff brown shaley marlstone of the...

The successful exploration and development of shale oil in the clay-rich Gulong shale have sparked increased research into the influence of clay minerals on shale reservoirs. However, compared to chlorite in sandstones, limited studies have focused on the occurrence of chlorite in continental shales and its effects on shale reservoir properties. Th...

In order to reveal the microstructure control mechanism of the thick conglomerate layer in the process of rock burst inoculation and occurrence in Yima mining area, the mineral composition, cementation structure and micromechanical characteristics of typical conglomerate samples were systematically analyzed based on scanning electron microscope (SE...

The Utch Khattak Limestone (Late Precambrian), exposed in the southern Gandghar Range of District Haripur, has experienced significant diagenetic alteration due to the intrusion of doleritic dikes. These dikes, widespread across the study area, have occluded pore spaces and fractures in the host limestone, leading to notable mineralogical changes f...

Kaolinite-rich clays are the most utilized clay type as a supplementary cementitious material (SCM) due to their higher pozzolanic reactivity. However, these higher-grade clays may not be available due to widespread usage in other industries and geographical locations. Hence, this study investigates the potential of combining low-grade illite clays...

The Mars Science Laboratory rover, Curiosity, has been examining strata from a period of Martian history where extensive clay mineral formation transitioned to sulfate mineral formation. This mineralogic change corresponds to a change from a wetter to a more arid climate. Among the tools used by Curiosity to study the rocks that recorded this trans...

Hydraulic fracturing has significantly advanced shale oil extraction, yet the long-term effects of fracturing fluids on pore structure remain inadequately understood. This study marks the first quantitative evaluation of the pore structure evolution induced by the fracturing fluid–rock interaction. The mineral composition, pore types, morphology, p...

With the rapid development of the coalbed methane (CBM) industry in China, coal seam No. 8 of the Benxi Formation in the Ordos Basin has emerged as a key target for CBM development due to its abundant deep reserves. However, wellbore instability during deep CBM extraction has become increasingly problematic, with the degradation of coal mechanical...

The shallow hydrate reservoir in the Shenhu Sea area is mainly composed of clayey silt. Clay mineral has an important impact on the mechanical properties, and the hydrate decomposition aggravates this impact. Therefore, the composition and geological conditions of shallow clay hydrate-bearing sediment in Shenhu sea area are fully considered, hydrat...

In order to further study the pore structure characteristics of mixed-sediments reservoir and the fractal characteristics of pores at different scales, 6 rock samples of mixed-sediments reservoir in Upper Youshashan Formation of NYS oilfield were selected. Based on rock physical properties, X-ray diffraction, low temperature CO2/N2 adsorption and h...

In the western Tarim Basin, Carboniferous granular dolostones deposited on a carbonate platform contain a small amount of terrigenous materials of sand-size fraction, agglomerated clay minerals, or similar phases. However, the role of terrigenous materials on dolomitization is still unclear. The aim of this study was to reveal the dolomitization me...

The article considers a possibility of using electrical resistivity tomography to assist the engineering and geological surveys conducted within coastal sea waters. The efficiency of electrical resistivity tomography in aquatic and seafloor modifications for investigating the structure of coastal territories of freshwater and sea water areas is est...

In sedimentary basins, the lithologic characteristics of mudstone in different lithofacies differ, which is caused by the different types of diagenesis after sedimentation. An accurate understanding of the changes in and interactions among minerals in mudstone during diagenesis plays a key role in shale oil and gas exploration and development. In t...

Satellite images are valuable resources for detecting surface manifestations of hydrocarbon-induced soils and sediments in potential petroleum reservoirs, particularly in inaccessible areas where field surveys are challenging. This study employed band ratio (BR) and principal component analysis (PCA) techniques to investigate hydrocarbon micro-seep...

To elucidate the removal mechanism for gangue (Al, Si, and P elements) components in low-grade iron ore using an alkaline hydrothermal treatment, model compounds of the gangue components were treated with a 5M NaOH solution using a bath-type reactor. The effective removal of P ions by alkaline treatment at room temperature suggests that these ions...

In order to identify potential zones for clay mineral (kaolinite) in Kankara, Northwest Nigeria, 2D ERT survey lines were deployed across potential site and collated to form a 3D ERT model. Although field surveys using this method is relatively straight forward, it requires the application of inverse methods prior to any interpretation. Several est...

In this work, a unique technique for replicating the void structure of a low-permeability reservoir in a silicon microfluidic chip has been developed. This technique is qualitatively superior to all previous ones and provides full repeatability of key parameters of the void structure (permeability; pore size distribution; average channel diameter;...

This paper explores the connection between microbial activities in clay formation, processing and ceramics design. The research focuses on unraveling the characteristics of microorganisms present within the Tinapa and Akpabuyo clay sites in Cross River State, Nigeria. Clay as a chemical compound known as Kaolinite (Al₂Si₂O₅(OH)₄ is the basic raw ma...

Research has delved into the main controlling factors for the evolution of the pore-fracture structure in deep coal samples. The gas content is influenced by multiple factors, among which the pore-fracture structure in deep coal samples stands as one of the key determinants. To ascertain the evolution of the pore-fracture structure and the main con...

Humin, as the most stable fraction in soil organic matter, determines possibility of sustainable environmental development by influencing, among other things, the binding and migration of different chemicals in soil. The aim of this paper was to determine changes in the properties of humins after interaction with three selected active substances of...

Ceramics Industry is the major consumer of industrial raw materials including various types of clay minerals. The existence of impurities in ceramic raw materials is a challenging issue to produce high quality ceramics. Coloring impurities such as Fe and Ti cause discoloration within the ceramic bodies and they have to be kept below certain limits....

Introduction With the gradual reduction in conventional exploration and the gradual improvement of hydraulic fracturing technology, the exploration of tight oil and gas has gradually become general. Marine carbonate rocks are developed in the lower Paleozoic Ordovician in the eastern margin of Ordos Basin. According to the drilling results, the min...

Background Biochar application has been widely acknowledged as an environment-friendly practice to promote soil organic carbon (SOC) stabilization and sequestration in agroecosystems. However, the interaction between fungal and minerals on organic carbon storage and stabilization with biochar application still remains unclear in saline-alkaline soi...

Background/Objectives: The persistence of tetracycline residues in aquatic environments poses substantial risks to ecosystems and public health, emphasizing the need for effective removal strategies. This study examines the use of purified stevensite (ST), a natural clay mineral, as an efficient and cost-effective adsorbent for removing tetracyclin...

The hallmark of lower Aptian sediments is commonly organic-rich black shales related to widespread oxygen deficient conditions known as ocean anoxic event 1a (OAE1a). The La Frontera section, located in the Subbetic Basin, southern Spain, documents the response to OAE1a within a ∼28 m interval divided into 3 units: U1 (before), U2 (during OAE1a), a...

The discharge of industrial wastewater containing toxic dyes has significantly increased, posing risks to human health and aquatic ecosystems. The growing demand for dyes in the textile industry has driven research into effective and economical removal methods. Adsorption is widely preferred due to its low cost, non‐toxic by‐products, and eco‐frien...

Clay minerals are non-spherical nano-particles interacting through ranged van der Waals forces. Discrete Element Simulations usually use coarse numerical integration based on sphere clusters , as available analytical formalisms are limited. In this paper, we discuss the numerical implementation of a van der Waals force for cuboid particles derived...

Shale gas is a vital transitional energy source during the energy transformation period. With the ongoing development of the Longmaxi Formation shale gas field in the Sichuan Basin, identifying new alternative stratigraphic sequences has become a key focus of current shale gas exploration. The Upper Permian Longtan and Wujiaping Formations in the S...

The physical and mechanical properties of grouting material are critical indicators to assess its compatibility to earthen archaeological sites as a fissure repair material. This study activated the clay from Huangshan Archaeological Site by calcination to explore how calcined clay enhances the age performance of grouting material with various temp...

Sandy red clay, abundant in clay minerals, exhibits a marked sensitivity to variations in water content. Several of its properties are highly prone to deterioration due to wet–dry cycling, potentially leading to slope instability. To investigate the multi-scale deterioration patterns and the underlying chain mechanism of sandy red clay subjected to...

This study focuses on the Hailijing sandstone-hosted uranium deposit in the Songliao Basin. Through a combination of petrographic analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), and geochemical analysis, the epigenetic alteration of the deposit was systematically investigated, and the alteration zonation was delineated. On th...