Primary Minerals Research Articles

Distribution and Enrichment of Au, Hg, and Tl in the Lanmuchang Deposit, Guizhou, China

Mineralization characterized by Au, Hg, and Tl enrichment is rare, and research on Au, Hg, and Tl mineralization is limited. The Lanmuchang Au–Hg–Tl deposit is located in the “Golden Triangle” of Yunnan, Guizhou, and Guangxi Provinces in China. In this study, we used scanning electron microscopy (SEM), electron microprobe analysis (EPMA), and a Tescan integrated mineral analyzer (TIMA) to analyze the mineral composition and distribution of the different types of ores and identify the occurrence state and enrichment mechanism of ore-forming elements in the Lanmuchang deposit. The results show that the primary ore minerals in the Lanmuchang deposit are pyrite, cinnabar, and lorandite. Cinnabar is the primary carrier of Hg (>90%), and pyrite is the primary carrier of Tl (>60%). Gold, Hg, and Tl primarily occur as solid solutions in hydrothermal pyrite, whereas they primarily occur as nano-scale particles in diagenetic pyrite. The substitution of As for S in hydrothermal pyrite promotes Au enrichment. The coupled substitution of 2Fe2+ ⇔ Tl+ + As3+ may be a significant Tl incorporation mechanism and promotes the occurrence of Hg in pyrite. The As and Se contents and Cu/Au and Co/Ni ratios of the hydrothermal pyrite demonstrate that the ore-forming fluid was mostly in a low-temperature, low-salinity, almost-neutral pH, and nearly reducing environment. The results show that the mineralization of the Lanmuchang deposit is associated with the cooling, oxidation, water–rock interaction, and boiling processes of the ore-forming fluid(s).

Late Neoproterozoic alkaline intrusives in Huqf sediments; a new reservoir target in southern Oman

Abstract Recent drilling in Block 56 on the southern Oman coast NE of Salalah has revealed the presence of intrusive rocks in Huqf sediments. The igneous bodies are found as both discrete and composite, decametre scale sills separated by screens of Huqf host rock. Compositionally they form a cogenetic suite of monzonites and syenites that can be related by fractional crystallization to a gabbro–diorite parental magma. Enrichment in alkalis and other large ion lithophile elements points to either an enriched mantle source or magma-crust interaction on ascent. Geochemical profiles match closely those of the latest Neoproterozoic alkaline eruptives now found as exotic volcanic blocks entrained in the salt diapirs of the Ghaba Salt Basin. Limited geochronological data indicate that the Block 56 intrusives are contemporaneous and derived from the same magma source. Porosities in excess of 10% have been recorded in the intrusives; it is a dissolution porosity created by volume loss during the conversion of primary ferromagnesian minerals to biotite and ferroan dolomite. Porosity creation took place during a short lived, fault-controlled Cretaceous hydrothermal event contemporaneous with uplift and alkaline volcanic activity in the Masirah Ophiolite. The intrusives contain a Huqf-sourced oil with light to medium viscosity appearance. Charging is believed to be coming from the cooler and shallower parts of the South Oman Salt Basin to the north and from beneath thick Cenozoic cover in the basin to the south.

IDENTIFIKASI MINERAL SEKUNDER UNTUK MENILAI POTENSI TANAH LAHAN PERTANIAN CABE HIYUNG DI DESA HIYUNG KABUPATEN TAPIN KALIMANTAN SELATAN

Hiyung Village is part of Tapin Tengah District, Tapin Regency, South Kalimantan. Besides rice, superior agricultural commodities in this village is Hiyung Cayenne Pepper. High demand and prices have caused more and more cayenne pepper to be cultivated. Hiyung Cayenne Pepper Cultivation is expected to increase farmers' income, so efforts are needed so that agricultural activities can continue. The sustainability of agricultural can be maintained if they are managed well. Appropriate management actions can be implemented if the soil and land characteristics are known. Soil is one of the things that really determines the success of an agricultural business, especially the availability of nutrients. Analysis of the secondary mineral composition of soil (sand) is very important in order to determine the nutrient reserves in the soil. Information about nutrient reserves in the soil can be used as a basis for good soil management so that it meets plant needs and does not cause damage to the soil and the environment. The specific aim of this research is to determine the composition of primary minerals (sand) to identify nutrient reserves in the soil. This research was carried out using a survey method to obtain data or information on soil and land characteristics and current management. Observations and soil sampling in the field were carried out at 5 locations with a distance of 1 km between locations. Sand mineral analysis uses a polarizing microscope to determine the mineral composition. Primary minerals (sand) at the research location are dominated by rock fragments and quartz. The weatherable mineral content is very small so the potential for nutrient reserves is very small.

Garnet and Zircon U‐Pb Geochronology and Geochemistry Reveal Genesis of the Dafang Au‐Pb‐Zn‐Ag Deposit, Southern Hunan

AbstractGarnet is a primary mineral in skarn deposits and plays a significant role in recording copious mineralization and metallogenic information. This study systematically investigates the geochemistry and geochronology of garnet and zircon in the Dafang Au‐Pb‐Zn‐Ag deposit, which represents prominent gold mineralization in southern Hunan, China. Garnet samples with distinct zoning patterns and compositional variations were identified using various analytical techniques, including Backscattered Electron (BSE) imaging, Cathodoluminescence (CL) response, textural characterization, and analysis of rare‐earth elements (REE), major contents, and trace element compositions. The garnet was dated U‐Pb dating, which yielded a lower intercept age of 161.06 ± 1.93 Ma. This age is older than the underlying granodiorite porphyry, which has a concordia age of 155.13 ± 0.95 Ma determined by zircon U‐Pb dating. These results suggest that the gold mineralization may be related to the concealed granite. Two groups of garnet changed from depleted Al garnet to enriched Al garnet, and the rare earth element (REE) patterns of these groups were converted from light REE (LREE)‐enriched and heavy REE (HREE)‐depleted with positive europium (Eu) anomalies to medium REE (MREE)‐enriched from core to rim zoning. The different REE patterns of garnet in various zones may be attributed to changes in the fluid environment and late superposition alteration. The development of distal skarn in the southern Hunan could be a significant indicator for identifying gold mineralization.

Is There a Carbonated Mid‐Lithosphere Discontinuity in Cratons?

AbstractThe mid‐lithosphere discontinuity (MLD), identified by a sharp velocity drop at ∼70–100 km depths within the cratonic lithosphere is key to comprehending the chemical composition and thermal structure of the cratonic lithosphere. The MLD is widely accepted to be caused by composition anomalies, such as hydrous minerals, which show low velocities and high electrical conductivities. However, noticeable high‐electrical conductivity anomalies have not been detected in the most cratonic lithosphere. Dolomite has an electrical conductivity similar to olivine and can be originated by carbonatitic melts trapped at ∼80–140 km depths. Here we investigated the elasticity of dolomite under mantle conditions using ab initio calculations and found dolomite exhibits significantly lower velocities than the primary minerals in the lithospheric mantle. Therefore, the dolomite enrichment might provide a good explanation for the observed velocity drop of the MLD in cratonic regions where no high‐conductivity anomaly has been detected, such as the northern Slave craton.

Mineralogy and weathering of REE minerals in the Liuchen granite, Guangxi, southern China: Implications for HREE enrichment in the granite regolith

Regolith-hosted ion-adsorption REE deposits (IARDs) in southern China were derived predominantly from the weathering of granitoids. However, the role of primary REE minerals in the formation of a REE-rich regolith during weathering of the granites has not been fully understood. To investigate the formation process of IARDs, fresh granite samples and regolith samples from different horizons (i.e., fully-, highly-, and semi-weathered horizons) in the Liuchen (LC) super-large IARD of Guangxi Province, southern China were collected and studied the compositions of the REE minerals. Allanite-(Ce), monazite, apatite, and zircon are major primary LREE-bearing minerals in the LC granite, and xenotime-(Y) is the major host of HREEs, including Gd, Dy, Er, Yb and Y (up to 38.68 wt%). Altered anhedral xenotimes are observed recrystallized as a result of the breakdown of apatite. These xenotimes have elevated contents of HREEs compared with their precursors. The sizes of these altered xenotimes are significantly smaller (mostly 0.5–5 μm) compared to the primary xenotimes (>50 μm). The increased surface-to-volume ratio for smaller particle sizes of these altered xenotimes make them more susceptible to weathering during supergene alteration. Except for zircon, the volume of primary REE minerals is reduced in zones of intense weathering (fully- and highly-weathered horizons) in the granite regolith, but relics of xenotime which covered by biofilms on their surfaces were observed in the incipient zones of weathering (e.g., in the semi-weathered horizon). Dissolution that begins at their surfaces from nano-scale was observed in these mineral relics. Microbial solubilization of this previously thought insoluble REE phosphate is likely to control the mobilization REE content, especially Y, in the LC granite regolith. Secondary cerianite-(Ce) and LREE- and HREE-bearing phosphates, mainly rhabdophane and florencite, were identified in the regolith, and this is evidence that HREE minerals such as xenotime-(Y) that were undergoing bio-weathering were an important source of materials for the formation of REE-bearing secondary minerals. This may provide new insights into the formation of so-called “ion-adsorption” REE deposits.

The First (and Second) Known Occurrences of Bazzite in Canada – The Quadeville Rose Quartz Quarry, Ontario, and the Bugaboo Castles Aquamarine Deposit, British Columbia – Description and Crystal Structure

Abstract Bazzite, ideally Be3Sc2Si6O18, has been discovered for the first time at two granitic pegmatite localities in Canada: the Quadeville Rose Quartz quarry, Ontario (Bz-ON/CMNMC 90604), and the Bugaboo Castles aquamarine deposit, Purcell mountains, British Columbia (Bz-BC/CMNMC 90725). Bazzite from both Canadian localities occurs as colorless, hexagonal prismatic to acicular crystals up to 0.6 mm in length. The crystal chemistry and structure of the two samples, Bz-ON and Bz-BC, was determined and compared with bazzite from other known occurrences. The average composition of Bz-ON is Be2.99(Sc1.39Mg0.37Fe3+0.10Fe2+0.09Al0.06Mn0.01)Σ2.02Si5.99O18·[Na0.47(H2O)], and that of Bz-BC is Be3.00(Sc1.43Fe2+0.28Mg0.20Al0.05Fe3+0.03Mn0.01)Σ2.01Si6.00O18[(Na0.46Cs0.01)Σ0.47(H2O)]. Bazzite from the Quadeville Rose Quartz pegmatite contains Mg = 0.33–0.41 (avg. 0.37) apfu, Fe3+ = 0.00–0.18 (avg. 0.10) apfu, and Fe2+ = 0.05–0.13 (avg. 0.09) apfu, whereas bazzite from Bugaboo Castles is more Fe2+-rich, with Fe2+ = 0.19–0.38 (avg. 0.28) apfu, Mg = 0.16–0.22 (avg. 0.20) apfu, and Fe3+ = 0.00–0.08 (avg. 0.03) apfu. Both samples have low Al, Mn, Ca, and Cs contents and, compositionally, are more similar to bazzite from alpine fissures and orogenic pegmatites than that from more common anorogenic NYF pegmatites. Bazzite from Canada is hexagonal, P6/mcc, with unit cell parameters a = 9.52741(14), c = 9.19326(15) Å for Bz-ON and a = 9.54396, c = 9.16495(20) Å for Bz-BC, respectively. The structure is composed of SiO4 tetrahedra that share corners to form Si6O18 rings perpendicular to the c axis. Each Si6O18 ring is linked via corners to a 12-membered ring of edge-sharing BeO4 tetrahedra and AO6 octahedra (A), resulting in channels parallel to the c axis (2a and 2b sites). Voids in the channels contain H2O (2a) and large alkali cations (Na, 2b). Both Bz-ON and Bz-BC have fully occupied 2a sites and 2b sites which are 50% occupied by Na. Increased substitution of the smaller cations Mg ([6]r = 0.72 Å) and Fe3+ ([6]r = 0.65 Å) for Sc ([6]r = 0.75 Å) results in significant changes in the bazzite structure, including a decrease in the <A–O> distance and decreased distortions (compression) in the AO6 and SiO4 tetrahedra. Bazzite from Quadeville and Bugaboo Castles are late-stage minerals, the product of breakdown of beryl and/or bertrandite and a Sc-bearing mineral. At Bugaboo Castles, bazzite is the result of alteration of Sc-rich spessartine (up to 3000 ppm) and primary beryl by late-stage OH-bearing fluids. At Quadeville, the source of Sc for bazzite is less evident and suggested to be Sc-bearing columbite-group minerals (up to 0.23 apfu Sc), or primary ferromagnesian minerals.

A case study of the Yanshanian fluorite mineralization in South China: Fluid inclusion, element and isotope geochemistry and zircon U-Pb geochronology of the Kantian fluorite deposit in southern Jiangxi Province

The Yanshanian events have led to the development of South China as a unique granite province globally. Within South Jiangxi, numerous metallic and non-metallic deposits have a close association with Mesozoic granite formations. The Kantian fluorite deposit, a newly discovered non-metallic deposit in southern Jiangxi Province, is one such deposit that is linked to Mesozoic granites. The orebody at the Kantian fluorite deposit is identified as occurring in veined structures within the silicification fracture zone of Mesozoic granites, with strict control exerted by fault systems. Fluorite ore can be classified into two categories based on the amount of quartz and fluorite. The first category is the fluorite quartz type, which has a higher amount of quartz than fluorite. The second category is quartz fluorite type, which has more fluorite than quartz. Among these two categories, the quartz fluorite type is precipitated during the primary mineralization stage. Through the analysis of fluid inclusions within the fluorite, it was determined that the homogenization temperature is relatively low, ranging from 133 to 236℃. The fluid inclusions also display low salinity (0.18–3.39 wt% NaCl eqv.) and low density (0.75–0.96 g/cm3). Laser Raman spectroscopy revealed that the primary components of the fluid inclusions are H2O, with minor C3H6. Isotope analysis indicated δDVSMOW values of fluorite ranging from −61.9 ‰ to −54.8 ‰ (average −59.8 ‰), while δ18OVSMOW values varied from 1.3 ‰ to 3.1 ‰ (average 2.0 ‰). This study presents chronological, petrological and geochemical data that suggest several processes. The metallogenic age is 135.6 ± 0.7 Ma. The mineralizing fluids were identified to the NaCl-H2O system, with heated meteoric water identified as the primary source; The ore-forming materials originated from the granite, and water–rock interactions are proposed as the primary mechanism for fluorite precipitation. Based on a tectonic setting characterized by stretching, which is closely linked to the subduction of the Pacific plate, we proposed a model for the Kantian fluorite deposit.

In situ apatite and carbonate Lu-Hf and molybdenite Re-Os geochronology for ore deposit research: Method validation and example application to Cu-Au mineralisation

The development of laser ablation inductively coupled plasma quadrupole tandem mass spectrometry (LA-ICP-Q-MS/MS) opens new opportunities to rapidly date a variety of hydrothermal minerals. Here we present in situ Lu-Hf and Re-Os dates for hydrothermal apatite and molybdenite, respectively. We further report the first in situ Lu-Hf dates for bastnäsite, dolomite, and siderite, and assess their potential for constraining ore deposit geochronology. For method validation, we report isotope-dilution Lu-Hf dates for apatite reference material Bamble-1 (1102 ± 5 Ma) and calcite reference material ME-1 (1531 ± 7 Ma), enabling improved accuracy on matrix-matched calibration for LA-ICP-MS/MS Lu-Hf dating. The new methods are applied to the Vulcan Iron-Oxide Copper-Gold (IOCG) prospect in the Olympic Cu-Au Province of South Australia. Such deposits have been difficult to accurately date, given the general lack of reliable mineral geochronometers that are cogenetic with IOCG mineralisation. Hydrothermal apatite Lu-Hf dates and molybdenite Re-Os dates demonstrate that mineralisation at Vulcan largely occurred at ca. 1.6 Ga, contemporaneous with the world class Olympic Dam deposit. Our data also indicates that the Lu-Hf system in apatite is more robust than the U-Pb system for determining the timing of primary apatite formation in an IOCG system. We further demonstrate that dolomite can retain Lu-Hf growth ages over an extended time period (>1.5 billion years), providing constraints on the timing of primary ore mineral crystallisation during brecciation and IOCG mineralisation. Finally, late Neoproterozoic (ca. 589–544 Ma) and Carboniferous (ca. 334 ± 7 Ma) Lu-Hf dates were obtained for texturally late Cu-bearing carbonate veins, illustrating that the carbonate Lu-Hf method allows direct dating of Cu remobilisation events. This has important implications for mineral exploration as the remobilised Cu may have been transferred to younger deposits hosted in Neoproterozoic sedimentary basins overlaying the Olympic IOCG province.

Study on improving the crack self-healing width and depth based on microbial mineralization modified by Ca–Al bimetallic hydroxides

In-depth research was conducted on the application of an inorganic mineral composite microbiological remediation agent in mortar specimens with varying crack widths. Firstly, the remediation agent's efficacy in repairing cracks was validated through surface observations and macroscopic performance tests, including methods such as crack surface image capture, crack water permeability recovery rate testing, and crack ultrasonic velocity recovery testing. Subsequently, this study investigated whether the inorganic mineral and microbiological components in the remediation agent played a role by examining the repair products within the cracks. Material composition was identified using techniques such as Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), and Fourier Transform Infrared Spectroscopy (FTIR). The primary minerals identified were layered double hydroxides and calcium carbonate. Furthermore, it was found that CI− and SO42− ions were immobilized within the interlayers of layered double hydroxides, aligning with the expected objectives of the experiment, thus confirming the feasibility of this study. Finally, the self-healing mechanism of cracks in this experiment was elucidated through a schematic diagram, demonstrating that the use of layered double hydroxides as inorganic minerals improved the microenvironment of the crack area, lowered the pH in the crack region, providing a favorable environment for microbial growth and mineralization. Additionally, these minerals could adsorb erosive ions such as CI− and SO42−, thereby enhancing the durability of cement-based materials.

New insights into the origin and depositional setting of the Haerdaban Pb[sbnd]Zn deposit, Chinese western Tianshan: Evidence from geology, chert geochemistry, and detrital zircon U[sbnd]Pb geochronology

The Haerdaban PbZn deposit (with an ore reserve of 10.93 Mt. at 1.0–25.65 % Zn and 0.7–12.29 % Pb) is hosted in weakly metamorphosed clastic‑carbonate rocks from the Proterozoic Haerdaban Group. It represents a significant addition of the sediment-hosted PbZn deposits in the Yili block, Chinese western Tianshan. Currently, there are ongoing debates regarding its genesis, with a particular focus on the crucial metallogenic mechanism (syngenetic sedimentary exhalation or epigenetic reworking) responsible for the primary sulfide mineralization. Mineralization at Haerdaban primarily occurs as banded to stratiform ore layers or lenses conformably sandwiched in their host rocks. Vein and stockwork ores occur locally below the stratiform ore layers. A syn-sedimentary fault trending SN was identified based on abrupt lateral changes in lithofacies and thickness of the stratigraphic units. The ore mineralogy is dominated by sphalerite, galena, quartz, and dolomite, with a small amount of pyrite, barite, and organic matter. Detrital zircon LA-ICP-MS UPb dating of the Haerdaban siltstones obtained a maximum depositional age of about 604 Ma. Their geochemical composition similar to the passive continental margin signatures, with rare earth element (REE) patterns enriched in LREE and negative Eu anomalies (Eu/Eu* = 0.50–1.14). Stratiform beds of chert that host disseminated ores have relatively high contents of hydrothermal components (e.g., Ba, Zn), with apparent positive Eu anomalies (Eu/Eu* = 7.38–49.34) and negligible negative Ce anomalies (Ce/Ce* = 0.85–0.98). They are thus interpreted to be hydrothermal sedimentary rocks (exhalites) deposited in a suboxic-anoxic environment proximal to the hydrothermal vents. Integrated geological and geochemical evidence indicates that the Haerdaban PbZn deposit is a typical vent-proximal sedimentary exhalative (SEDEX) deposit formed in a Neoproterozoic Sinian (Ediacaran) passive continental margin rift basin. Post-depositional metamorphism and deformation in the Paleozoic may have caused partial remobilization of primary ores but did not significantly alter the morphology of the orebodies. Furthermore, establishing a genetic model for the Haerdaban deposit has important implications for the exploration of similar deposits preserved in the equivalent stratigraphy within the Chinese western Tianshan region.

Valorization of the Residual Fraction of Coal Tailings: A Mineral Circularity Strategy for the Clay Ceramic Industry in the Carboniferous Region of Santa Catarina, Southern Brazil.

Mineral extraction of coal in the carboniferous region of southern Santa Catarina (Brazil) plays a significant role in the regional economy. However, this activity has severe environmental impacts, with approximately 65% of the extracted mineral being discarded as a rejected material (deposited in landfills). The identification of the technological potential of these materials, based on the geological aspects of the extraction site and the beneficiation operations applied to obtain coal, provides the opportunity to add value to different residual fractions that can be reused. Thus, waste valorization, the main objective of this work, has recently become a strategy for the application of these minerals in the production of clay ceramics using a systematic approach named CPQvA, which means "classification, potentiality, quantity/viability, and applicability". The use of these materials as secondary mineral sources can avoid the deposition of these materials in industrial landfills and help to reduce the pressure on landfills, which receive an average of four million tons of material annually. In this study, the residual fraction, part of the tailing from coal beneficiation, known as coal fines, was evaluated for formulation valorization in clay ceramics. This residual fraction was classified as non-hazardous (class II-A, non-inert). X-ray fluorescence spectrometry, X-ray diffraction, and thermogravimetric analysis were performed to characterize the moisture content, particle-size distribution, and coal content to be used in the development of different formulations using the residual fraction of coal tailings (ranging from 0 to 40%) that are of technological interest to the sector. Processing parameters, such as firing at different temperatures (750, 800, 850, and 900 °C), were also correlated with these formulations. The results were compared with those of a reference ceramic formulation from the local productive arrangement of Morro da Fumaça (Arranjo Produtivo Local Cerâmica Vermelha de Morro da Fumaça). The various relationships between the materials were characterized in terms of their thermal shrinkage, water absorption, and mechanical resistance. Leaching and solubilization environmental tests revealed that both the industrial standard formulation and formulations with the application of the residual fraction were classified as non-hazardous materials. Thus, the method of using a mining residual fraction in the formulation of clay ceramics proved to be beneficial for the circular economy in the regional mineral sector through productive and environmental gains; the primary mineral resource and energy consumptions and the impacts related to waste generation were reduced. The results of this study can be applied to similar situations in other parts of the world.

Soils on Recent Tephra of the Somma–Vesuvius Volcanic Complex, Italy

The Somma–Vesuvius volcanic complex emitted huge quantities of volcanic materials over a period from before 18,300 years BP to 1944. The activity during the last period, from post-AD 1631 to 1944, primarily produced lava and pyroclastics via effusive and strombolian eruptions. We investigated the pedogenesis on rocks formed from post-AD 1631 to 1944, occurring on the slopes of Mt. Vesuvius up to Gran Cono Vesuviano and in the northern valley separating Vesuvius from the older Mt. Somma edifice. Pertinent morphological, physical, chemical, and mineralogical (XRD and FT-IR) soil properties were studied. The results indicated the existence of thin and deep stratified soils on lava, as well as the presence of loose detritic covers formed via pyroclastic emplacement and redistribution. The soils showed minimal profile differentiation, frequently with layering recording the episodic addition of sediments. We found that the dominant coarse size of primary mineral particles was preserved, and there was a low level of clay production. The main mineralogical assemblage present in sands also persisted in clays, indicating the physical breaking of the parent material. Chemical weathering produced mineral modifications towards the active forms of Al and Fe and was also attested in selected soils by glass alteration, allophane production, and the presence of analcime in clay as a secondary product from leucite. The differences in glass alteration and analcime production found in the selected soils on lava were related to soil particle size and soil thickness. Concerning the youngest soil present on Gran Cono Vesuviano, other factors, such as the substratum’s age and site elevation, appeared to be implicated.

The impact of hydroxyapatite crystal structures and protein interactions on bone's mechanical properties

Hydroxyapatite (HAP) constitutes the primary mineral component of bones, and its crystal structure, along with the surface interaction with proteins, significantly influences the outstanding mechanical properties of bone. This study focuses on natural hydroxyapatite, constructing a surface model with calcium vacancy defects. Employing a representative model of aspartic acid residues, we delve into the adsorption mechanism on the crystal surface and scrutinize the adsorption forms of amino acid residues on HAP and calcium-deficient hydroxyapatite (CDHA) surfaces. The research also explores the impact of different environments on adsorption energy. Furthermore, a simplified sandwich structure of crystal-polypeptide-crystal is presented, analyzing the distribution of amino acid residue adsorption sites on the crystal surface of the polypeptide fragment. This investigation aims to elucidate how the stick–slip mechanism of polypeptide molecules on the crystal surface influences the mechanical properties of the system. By uncovering the interface mechanical behavior between HAP and osteopontin peptides, this article offers valuable theoretical insights for the construction and biomimetic design of biocomposites.

Petrography and Geochemistry of Limestone Upper Cretaceous Kometan Formation (Azmir Anticline): A Preliminary Assessment for Cement Production Suitability in the Kurdistan Region Northeast Iraq

A succession of slightly siliceous limestone of the Kometan Formation is studied geochemically and strati graphically. The studied area is located on the SW limb of the Azmir anticline at the northeastern of Sulaimaniyah city. The studied section is situated at longitudes 45°38'310"E and latitudes 35°36'129''N inside the Folded Zone, Kurdistan Region, northeastern Iraq. The exposed section is sampled for lab studies, and inspected by eyes and hand lenses in the field. In this study, petrographic and geochemical analyses of 17 limestone samples were carried out. This study aims to investigate the major oxides of the limestone samples, using the X-Ray Fluorescence (XRF), for preliminary assessment for possible cement production. A petrographic study was also carried out, in order. Depending on the petrographic study, three major microfacies were recognized: lime mudstone microfacies, lime wackestone microfacies, and lime packstone microfacies, which subdivided into four submicrofacies are planktonic foraminifera lime mudstone submicrofacies, planktonic foraminifera lime wackestone submicrofacies, and planktonic foraminifera lime packstone submicrofacies and heterohelix lime packstone submicrofacies. The geochemical analysis shows that a range of variations in constituents: LOI (35.90% to 42,72%), SiO2 (3.77% to 14.66%), CaO (42.59% to 49.95%), Al2O3 (0.44% to 2.22%), Fe2O3 (0.02% to 0.78%) and MgO (1.50% to 2.26%); K2O and Na2O are present in traces. The high CaO (49.95%) indicates that calcite is the primary carbonate mineral. Due to mineralogical considerations, CaO with LOI shows a positive correlation, whereas CaO with SiO2 shows a negative correlation. The low MgO contents in calcitic limestone and calcitic limestone with chert nodules recommend a lack of dolomitization process. The silica modulus and lime saturation factor from geochemical data indicated that the siliceous limestone samples from the Kometan Formation and Azmir Anticline can be used in the cement-making process provided they are processed for silica removal treatment to reduce its percentage to less than 8%, as required level, where the CaO can be automatically enriched. Depending on field observation, petrography, and geochemistry analysis, we conclude that the source of the chert or silica minerals is diagenetic processes and depositional environment origin.

Fe–Cu mineralization of Tangal-e-Sefid; a magnetite rich massive sulfide deposit from Kuh-e-Sarhangi district, Central Iran

The Tangal-e-Sefid Fe–Cu mineralization forms syngenetic stratiform deposit in the Late Neoproterozoic volcano sedimentary sequence from the Central Iran. Early Cambrian metamorphic rocks are associated ore-bearing geologic units. The mineralization includes early oxide phase as a magnetite-rich bodies that are overprinted by a pyrite-chalcopyrite-rich sulfide phase. The most current alteration zone includes propylitic-carbonate, chlorite, sericite and silicic with a well-developed distribution of chloritization, especially in the layered part. Magnetite, pyrite and chalcopyrite comprise the primary main mineral assemblage, which is accompanied by malachite, covellite, hematite and goethite as the secondary minerals associated with epidote, chlorite, quartz and calcite minerals. Magnetite chemistry reveals the hydrothermal evolution of mineralization, and all the examined magnetite fall within fields of magnetite from VMS deposits. Fluid inclusion analysis of quartz and calcite coexisting with magnetite represent homogenization temperature range of 198 °C and 357 °C with a cooling trend from the massive toward the layered parts. The measured fluid salinity identifies two distinct medium-salinity fluids with mean values corresponding to 15 and 22 wt% NaCl. There is no significant difference in terms of temperature and salinity measured in calcite and quartz minerals. However, the average measured temperature values of fluids trapped in calcite (189–336 °C) are slightly lower than quartz (227–357 °C). Since the ore deposit distribution is spatially associated with actinolite schist, thermometric data of actinolite show temperature fluctuations of 310–315 °C and mineral formation pressures of 2.5–3 Kbar, which are correlated with the low-grade metamorphism.Primary hydrothermal fluids derived from submarine magmatism in an extensional system of seafloor were enriched in Fe and Cu (± Zn and possibly Pb) and it is the responsible for the first stage of magnetite formation and following the overprinting pyrite and chalcopyrite mineralization. The ore deposit geometries associated with magnetite mineralization and sulfide replacement styles; reveals that in the second stage of mineralization, hydrothermal fluid is mixed with oceanic water and eventually metal sulfides are deposited. The mineralizaton zone associated with the volcano-sedimentary sequence is affected by low-grade regional metamorphism related to Pan-African orogeny and represent the green schist territory as the VMS deposits related to Archean.

Skeletal parathyroid hormone hyporesponsiveness: a neglected, but clinically relevant reality in chronic kidney disease.

Defining the optimal parathyroid hormone (PTH) target in chronic kidney disease (CKD) is challenging, especially for bone outcomes, due to the substantial variability in the skeleton's response to PTH. Although PTH hyporesponsiveness is as integral a component of CKD-mineral bone disorder as elevated PTH levels, clinical awareness of this condition is limited. In this review, we will discuss factors and mechanisms contributing to PTH hyporesponsiveness in CKD. This knowledge may provide clues towards a personalized approach to treating secondary hyperparathyroidism in CKD. Indicates a link between disturbed phosphate metabolism and impaired skeletal calcium sensing receptor signaling as an important mediator of PTH hyporesponsiveness in CKD. Further, cohort studies with diverse populations point towards differences in mineral metabolism control, rather than genetic or environmental factors, as drivers of the variability of PTH responsiveness. Skeletal PTH hyporesponsiveness in CKD has a multifactorial origin, shows important interindividual variability, and is challenging to estimate in clinical practice. The variability in skeletal responsiveness compromises PTH as a biomarker of bone turnover, especially when considering populations that are heterogeneous in ethnicity, demography, kidney function, primary kidney disease and mineral metabolism control, and in patients treated with bone targeting drugs.

Occurrence and mobility of thiolated arsenic in legacy mine tailings

We studied the occurrence of dissolved thiolated Arsenic (As) in legacy tailings systems in Ontario and Nova Scotia, Canada, and used aqueous and mineralogical speciation analyses to assess its governing geochemical controls. Surface-accessible and inundated tailings in Cobalt, Ontario, contained ∼1 wt-% As mainly hosted in secondary arsenate minerals (erythrite, yukonite, and others) and traces of primary sulfide minerals (cobaltite, gersdorffite and others). Significant fractions of thiolated As (up to 5.9 % of total dissolved As) were detected in aqueous porewater and surface water samples from these sites, comprising mostly monothioarsenate, and smaller amounts of di- and tri-thioarsenates as well as methylated thioarsenates. Tailings at the Goldenville and Montague sites in Nova Scotia contained less (<0.5 wt-%) As, hosted mostly in arsenopyrite and As-bearing pyrite, than the Cobalt sites, but exhibited higher proportions of dissolved thiolated As (up to 17.3 % of total dissolved As, mostly mono- and di-thioarsenate and traces of tri-thioarsenate). Dissolved thiolated As was most abundant in sub-oxic porewaters and inundated tailings samples across the studied sites, and its concentrations were strongly related to the prevailing redox conditions and porewater hydrochemistry, and to a lesser extent, the As-bearing mineralogy. Our novel results demonstrate that thiolated As species play an important role in the cycling of As in mine waste systems and surrounding environments, and should be considered in mine waste management strategies for high-As sites.

Enrichment mechanisms of Nb, Zr, and REY in the Late Permian coal-bearing strata in western Guizhou, SW China

Niobium, Zr, REE, and Y are widely enriched in the Upper Permian coal-bearing strata in southwestern China and are regarded as a substantial resource. To better understand the occurrence modes and enrichment mechanisms of these rare metals, comprehensive heavy-mineral separation, Micro-Raman spectroscopy, EPMA, and LA-ICP-MS analyses of primary and secondary metal minerals were conducted in the polymetallic beds in western Guizhou. In addition, the XRD, XRF, and ICP-MS analyses of bulk rocks were carried out. Our results suggest that Nb is primarily hosted in secondary TiO2 polymorphs which converted from primary Nb-rich rutile, and occurs as minor ilmenorutile and columbite-(Fe). The Zr is sequestered in both detrital zircon and secondary microcrystalline zircon. REE and Y (REY) are mainly incorporated into secondary florencite-(Ce), rhabdophane-(Ce), churchite-(Y), and zircon, also partially adsorbed by clay minerals. The assemblage of detrital zircon, Nb-rich rutile, and discrete Nb minerals reveals that rare metals are preconcentrated during the waning-stage Emeishan alkaline magmatisms. Complex zonings in rutile crystals may result from the diffusion of Nb5+ and Fe2+, and these grains are further overprinted by magmatic-hydrothermal and enveloped by ilmenorutile and columbite-(Fe). Furthermore, magmatic rutile is commonly converted into anatase, brookite, and leucoxene under supergene conditions, and then persisted as stable phases. Authigenic REY-rich (Al)-phosphates and zircon are sourced from the leaching, even decomposition of primary REY-phosphates and zircons. Their colloidal aggregates are precipitated from the acidic and oxidizing low-temperature fluids, which are superposed onto clay matrix. The mineralogical and geochemical features suggest that the polymetallic beds are enriched by both alkaline magmatic-hydrothermal processes in source rocks and supergene fluid alterations in sediments. This study gives new insights into the enrichment processes and conditions, and further extraction of critical metals in the coeval coal-bearing strata in southwestern China.

Oxygen Isotopic Variations in the Calcium, Aluminum-rich Inclusion–forming Region Recorded by a Single Refractory Inclusion from the CO3.1 Carbonaceous Chondrite Dar al Gani 083

Calcium, aluminum-rich inclusions (CAIs) are the oldest solids dated that formed in the solar system. Most CAIs in unmetamorphosed chondritic meteorites (chondrites; petrologic type ≤3.0) have uniform solar-like 16O-rich compositions (Δ17O ∼ −24‰) and a high initial 26Al/27Al ratio [(26Al/27Al)0] of ∼(4–5) × 10−5, consistent with their origin in a gas of approximately solar composition during a brief (<0.3 Ma) epoch at the earliest stage of our solar system. The nature of O-isotope heterogeneity in CAIs (Δ17O range from ∼−24 up to ∼+5‰) from weakly metamorphosed chondrites (petrologic type >3.0) remains an open issue. This heterogeneity could have recorded fluctuations of O-isotope composition of nebular gas in the CAI-forming region and/or postcrystallization O-isotope exchange of CAI minerals with aqueous fluids on the chondrite parent asteroids. To obtain insights into possible processes resulting in this heterogeneity, we investigated the mineralogy, rare-earth element abundances, and O- and Mg-isotope compositions of a CAI from the CO3.1 chondrite Dar al Gani 083. This concentrically zoned inclusion has a Zn-hercynite core surrounded by layers of (from core to edge) grossite, spinel, melilite, and Al-diopside. The various phases have heterogeneous Δ17O (from core to edge): −2.2 ± 0.6‰, −0.9 ± 2.1‰, −13.7 ± 2.1‰, −2.6 ± 2.3‰, and −22.6 ± 2.1‰, respectively. Magnesium-isotope compositions of grossite, spinel, melilite, and Al-diopside define an undisturbed internal Al–Mg isochron with (26Al/27Al)0 of (2.60 ± 0.29) × 10−6. We conclude that the variations in Δ17O of spinel and diopside recorded fluctuations in O-isotope composition of nebular gas in the CAI-forming region prior to injection and/or homogenization of 26Al at the canonical level. The 16O depletion of grossite and melilite resulted from O-isotope exchange with asteroidal fluid, which did not disturb Al–Mg isotope systematics of the CAI primary minerals.