Basaltic Minerals Research Articles

Coordinated microanalysis of volatiles in apatite and silicate minerals in ancient lunar basalts

Despite being essentially water-free, nominally anhydrous minerals such as plagioclase and pyroxene represent the biggest reservoir of water in most lunar rocks due to their sheer abundance. Apatite, which incorporates F, Cl, and OH into its mineral structure as essential crystal components, on the other hand, is the only other volatile-bearing phase common in lunar samples. Here, we present the first coordinated study of volatiles (e.g., H2O, Cl, F, and S) in nominally anhydrous minerals combined with isotopic measurements in apatite from the ancient lunar basalt fragments from meteorite Miller Range (MIL) 13317. Apatite in MIL 13317 basalt contains ∼ 2000 ppm H2O and has an elevated δD values (+ 523–737 ‰), similar to Apollo mare basalts, but has high δ37Cl values (+ 29–36 ‰), similar to apatite found in several KREEP-rich samples. MIL 13317 is unique compared with other lunar basalts; it has both elevated δD and δ37Cl values currently only observed in highlands sample 79215 (a granulitic impactite). Based on measurements of H2O in nominally anhydrous minerals and in apatite, the source magma of MIL 13317 basalt is estimated to contain ∼ 130–330 ppm H2O. Assuming reasonable levels of partial melting of the lunar mantle and magmatic degassing during eruption of the basalt, the Moon contained at least one reservoir with < 100 ppm H2O, a δD value of < 0 ‰ similar to carbonaceous chondrites, and extensively fractionated Cl isotopes prior to 4.332 Gyr, the crystallization age of the MIL 13317 basalt.

Gigaton commercial-scale carbon storage and mineralization potential in stacked Columbia River basalt reservoirs

This work presents a detailed supercritical CO2 storage resource estimation for the stacked basalt reservoirs in the Grande Ronde Basalt of the Columbia River Basalt Group in eastern Washington and Oregon. The assessment aims to derisk the commercialization potential of geologic carbon storage in basalt by leveraging both structural and mineralization trapping of CO2 in basalt. The structural closures formed by anticlinal ridges and synclinal valleys in Yakima Fold Belt are excellent physical traps to accommodate injected supercritical CO2. Rigorous hydraulic testing, well logs and simulation results from the Wallula Basalt Pilot #1 well showed the occurrence of 17 suitable permeable injection zones (up to 2,496 mD) intercalated with dense seals (∼2.6E-10 mD) in the Grand Ronde Basalt. In addition, geochemical studies showed fast reactions between supercritical CO2 and dissolved basalt minerals to form stable carbonates. Our calculation indicates up to 40 gigatons (P90) of mineralization storage resources exist in the Grande Ronde Basalt reservoirs.

Mineral powder based on basalt insulation waste for asphalt concrete

The article discusses the composition and production technology of mineral powder using waste basalt insulation. This study aims to confirm the hypothesis about the possibility of using basalt waste in the production of mineral powder with technical parameters corresponding to approved standards for the production of asphalt concrete. For definition of qualitative indicators of the received product in comparison with the control sample the researches of the basic indicators of mineral powder according to operating norms are given. Such indicators as grain composition of mineral powder, porosity and density were determined, indicating a more dense structure of the developed composition: the content of particles finer than 0.125 mm – 91.4 %, finer than 0.063 mm – 82.2 % with porosity index 28.1 % and true density 2.49 g/cm3. It was found that the mineral powder from waste basalt mineral slabs has a uniform and balanced grain distribution. At moisture content of samples less than 0.1 % by weight the bitumen capacity index of the tested mineral powder sample in comparison with the control sample showed better value by 2 g, at the same time the degree of swelling of samples from the mixture of powder and bitumen showed better result by 0.1 %. The obtained results indicate that the mineral powder on the basis of waste is able to hold bitumen well on its surface, which contributes to the improvement of adhesion between bitumen and mineral particles. The lower degree of swelling characterizes the increased water resistance and frost resistance of asphalt concrete with the use of this mineral powder. Considering that basalt mineral slabs are waste, their use in the production of mineral powder for asphalt concrete fits into the concept of sustainable construction and can contribute to waste reduction and environmental sustainability of the construction process.

Petrological, chemical, and chronological study of breccias in the Chang'e‐5 soil

AbstractWe carried out a petrological, mineralogical, and geochemical study of fragmental and regolith breccia clasts separated from two Chang'e‐5 (CE‐5) soil samples, CE5C0000YJYX03501GP and CE5C0400, which provide an opportunity to investigate the compositional change of regolith at the landing site through time. Fragmental breccia CE‐5‐B3 contains a diverse range of basaltic clasts and basaltic mineral fragments, and some rare Mg‐suite‐like minerals. Regolith breccias CE‐5‐B006, CE‐5‐B007, CE‐5‐B010‐08, CE‐5‐B010‐09, CE‐5‐B011‐07, and CE‐5‐B016‐03 contain mare basaltic fragments, mare vitrophyric clasts, rare Mg‐rich fragments possibly derived from the Mg‐suite rocks, and impact‐derived glass spherules. Pb‐isotope data obtained for baddeleyite grains found both inside some of the basaltic clasts identified in breccia fragments and in the breccia matrices yield Pb/Pb dates similar to the 2 Ga crystallization age of the CE‐5 basalt fragments, extracted directly from the soil sample. Seventy‐four Pb isotope analyses of Ca‐phosphate grains also indicate that the majority of these grains have Pb/Pb dates of 2 Ga, suggesting that they originate from the CE‐5 basalts. In addition, a Pb–Pb isochron drawn through analyses of four Ca‐phosphates in breccia CE5‐B006 yielded an intercept corresponding to a date of 3871 ± 46 Ma, which is the best possible estimate of the formation age of these four grains. Electron probe microanalysis shows that the breccias contain components similar to CE‐5 mare basalt fragments extracted directly from the soil sample, implying that the fragmental and regolith breccia fragments are mostly composed of material sourced from the underlying basalts. The general absence of impact melt breccia clasts, along with the general lack of Fe–Ni metal and absence of added meteoritic debris all suggest that the regolith at the CE‐5 landing site is immature and dominated by material mixed together by small local impact cratering events. Trace element analyses show that the glass beads in the regolith breccias have a Th abundance of 4.06–5.28 μg g−1. This is similar to the Th content of the regolith above the Em4 unit at the landing site as measured from orbit, as well as the estimated bulk Th content of CE‐5 basalts, suggesting that Th of the local regolith is predominantly sourced from the underlying mare basalts, without significant Th addition from Th‐rich exotic clasts sourced from evolved lunar lithologies.

Platinum-bearing Fe-Mn oceanic crust on basalts: mineralogy and model of formation

Fe-Mn oceanic crust on basalts of the guyot in the Mid-Pacific Seamount (Pacific Ocean, depth 2486 m, chemical composition (wt %): Mn 24.2, Fe 12.6, Ni 0.59, Co 0.72, Cu 0.13; (ppm) Pt 0.35, Pd 0.0052), was studied using 3D-technology of mineralogical research. In addition to dominaiting vernadite and goethite, the following minerals are identified in the hydroseparation (HS) concentrates of the crust: 1) rock forming and accessory minerals of basalts (clinopyroxene, plagioclase, potassium feldspar, biotite, ilmenite, titanomagnetite, Ti-chrome spinel, zircon, apatite); 2) sulfides that are identical to those from the basalt substrate (pyrite, chalcopyrite, bornite, chalcocite, tennantite, nickel pentlandite Ni4S3, sphalerite, galena, argentite/acantite, molybdenite); 3) native metals (iron, nickel, copper, titanium, tungsten); 4) iron silicides (gupeiite Fe3Si, xifengite Fe5Si3, and hapkeite Fe5Si3); 5) platinum group minerals - unnamed (Cu,Pt)4Si and rustenburgite (Pt,Pd)3(Sn,Sb). The complexes of ore minerals in basalts are identical to those of the Fe-Mn crusts. Basalt accessories are assumed to be primary phases and a source of metals for the formation of native minerals. “Microdroplets” of native iron Fe, (Fe,Ni), nickel Ni, (Ni,Cr), (Ni,Fe) and copper Cu (sizes 20–100 microns, degree of sphericity up to 100%) represent the products of their crystallization from metal melts in basalts, transported by deep fluid into Fe-Mn crusts on these rocks. The zoned microglobules of 20–70 microns sizes with iron or native nickel (core) + successive rims of wüstite-magnetite and Fe-Mn hydroxides were identified. They were apparently formed during the movement of these solid microparticles (from bottom to the top) along intergranular spaces and other permeability channels in basalts under conditions of increasing oxygen fugacity and falling temperature at various levels of deep fluid infiltration. The crystallization of native metals in the Fe-Mn crust that are characterized by low-temperature (10 °C) and oxidizing (fO2 MHG magnetite-hematite-goethite) conditions of mineral formation is impossible. The goethite replacement to different extent of many grains of relict Fe-minerals (sulfides and native metals) that are “foreign” to the Fe-Mn crust have been established. Fe-Mn crusts were formed as a result of the precipitation of colloidal particles Mn2+(Ba2+и Sr2+), to a lesser extent of the iron hydroxide Fe(ОН)3, as well as the concentration and transformation of micrograins of minerals of other metals, extracted by fluid from basaltic substrates. The comparison of the physico-chemical parameters of crystallization of basalts and native metals suggests another source of formation of native minerals in basalts, different from the postmagmatic basaltic fluid, i.e. deep-seated sharply reducing "hot" gas flows associated with superplumes. The mineralogical data determines a volcanogenic-fluid-oceanic model for the formation of Fe-Mn crusts on underwater oceanic elevations.

A quantitative study of changing groundwater-surface water interactions of a large reservoir due to impoundment based on hydrochemistry and isotope characteristics

Xiluodu Reservoir is the third-largest dam worldwide constructed in 2012. Significant changes in the hydrogeological conditions and regional groundwater-surface water (GW-SW) interactions associated since the dam impoundment in 2012 contributed to the river valley contraction (RVC). In this study, various factors that influence hydrochemistry and isotopic characteristics of GW-SW distribution interactions along with their migration patterns are extensively discussed. Based on these studies, the saturation index (SI) of different minerals during the GW-SW interaction in different periods was quantified considering the ion activity. The confined limestone GW and phreatic basalt GW are dominating GW in the dam site that play a predominant role in the regional GW-SW interactions. The impoundment strengthened the water–rock interaction and promoted the dissolution of minerals in limestone and basalt, contributing to an increase in the SI of different minerals in SW and GW. The primary recharge source for the limestone GW is Lake water; however, the secondary basalt GW recharge shifts from Ditch water to Reservoir water. The comprehensive studies summarized in this paper lays a foundation for rigorous understanding of the RVC mechanism that can be extended to other large reservoir projects in the world.

The geochemical evolution of basalt Enhanced Rock Weathering systems quantified from a natural analogue

Substantial quantities of fine-grained basaltic dust have fallen on South Iceland soils over at least the past 3300 years, making this region an ideal natural analogue to define the long-term consequences of current Enhanced Rock Weathering efforts. A relatively pristine South Iceland Gleyic/Histic Andosol, 3 m in height, receiving approximately 1250 mm of rainfall annually was selected for this study. This soil receives an estimated 500–800 g m−2y−1 of basaltic dust. The soil waters in this system were regularly sampled as a function of depth from May to November 2018. The fluid pH, alkalinity and the concentrations of most major elements increased with depth as the fluids became more reduced. In contrast, whereas numerous toxic trace metals are initially released to the fluid by the dissolution of the basalt near the surface they are scavenged at depth likely due to their uptake by secondary minerals. Equilibrium reaction path modelling suggests that 1) the added airborne basaltic dust dissolves throughout the soil column and 2) in total 0.26 cm3 of basalt dust dissolves per kg water in this soil–water system. Mass balance calculations indicate that the annual mass of basalt dissolved is less than 60 % of that added to the system, such that the mass of basaltic material in the soil column likely increases continuously over time. Basalt dissolution is maintained throughout the soil by the precipitation of Al-Si-minerals such as allophane, and organic anion ligands released from organic decay. These processes limit aqueous Al3+ activity and keep the soil waters undersaturated with respect to primary basaltic minerals and glass. The soil water pH is ∼6 and has a higher alkalinity than that of both Icelandic surface waters and the ocean. In contrast, if no basalt was present, the pH of the soil solutions would be 4.4, with zero alkalinity, illustrating the role of added basalt in drawing CO2 out of the atmosphere.

Specific features of basalts, its melting and tempering in different environments

The paper discusses the radical approach to expanding the possibilities of obtaining metals from untapped reserves of natural resources. It presents the results of scientific research dedicated to studying the specific components of the elements contained. The results of the preparation and implementation of smelting works at the basalt deposit ‘Asmansay-1ʹ are provided. The analysis of the results of melting basaltic minerals from the ‘Asmansay’ deposit is presented, along with their annealing in different environments. The aim is to determine the optimal parameters for the melting of basalt and similar ores.

ЭНЕРГОЗАТРАТЫ ПРОЦЕССА ПЛАВЛЕНИЯ БАЗАЛЬТА ЕНХОРСКОГО МЕСТОРОЖДЕНИЯ

Melting process is always accompanied by energy costs and losses, and its efficiency is determined primarily by energy efficiency index. The paper presents the results of energy consumption study of melting process of basalt from the Yenkhor deposit in plasma three-phase serial reactor and production of basalt mineral fibers. The main advantages of basalt fiber are low cost, high heat resistance, low thermal conductivity and environmental safety. The study calculates energy costs and determines composition of system under thermodynamic equilibrium conditions. Calculation of specific energy costs was performed using the TERRA software package. The article also provides an analysis of the obtained data and their comparison and reflects main phase transformations in melt.

Evaluation of Commercial Viability of Eco-friendly Alternatives to Traditional Floral Foam and Their Effects on Vase Life of Five Species of Cut Flowers

Increasingly, consumers are indicating that they would be willing to pay a premium for floral designs from a more sustainable floral provider. During the past several years, more environmentally sustainable floral foams and foam alternative media have been developed as an eco-friendly alternative to traditional floral foams comprised of phenol-formaldehyde plastics. Phenol-formaldehyde foam breaks down into microplastics, which ends up in landfills, soils, and waterways—including the planet’s oceans—if not disposed of properly. Eco-friendly foam alternatives are made from natural materials such as basalt minerals and coconut (Cocos nucifera) fiber (coir). The objective of this study was to investigate eco-friendly floral substrates for their commercial viability in the floral industry by analyzing the vase life of five of the most commonly use cut flower species in traditional vs. eco-friendly foam alternatives. Flowers selected for the experiment included ‘Freedom’ rose (Rosa hybrid), ‘Orange Queen’ alstroemeria (Alstroemeria hybrid), ‘Atlantis Yellow’ chrysanthemum (Dendranthema grandiflorum), ‘Pink Nelson’ carnation (Dianthus caryophyllus), and ‘Million Star’ baby’s breath (Gypsophila paniculate). The flowers were selected based on their importance to the floral industry with regard to their overall volume of use in floral arrangements and volume of production. The findings from this study indicate the traditional phenol-formaldehyde–based floral foam maintained vase life longer for a majority of the flowers tested when compared with basalt floral fiber medium and coir pouches. However, the basalt floral fiber medium maintained a vase life of more than 7 days for all flowers tested, indicating it is an adequate medium to use in retail floral design production. The coir pouch did not maintain the customer-expected vase life of 7 days for all but one of the cultivars tested. This indicates that coir pouches are generally not suitable for traditional everyday retail floral design use, but could potentially be acceptable for special occasion designs in which the consumer prefers or specifies a more sustainable approach and/or can accept a shorter vase life.

Improving Energy Efficiency in a Building Using Passive Energy-Saving Measures

Abstract We are going through a time when environmental, economic and social concerns, intensely amplified by climate change, by the depletion of resources, are growing. In this context, setting targets such as reducing energy consumption in the buildings sector, energy efficiency, and the use of renewable energies are becoming a priority, both at national and international level. Improving the energy efficiency of the existing building stock is important, not only for achieving national medium-term energy efficiency targets, but also for meeting the long-term objectives of the strategy on climate change and the transition to a competitive low-carbon economy by 2050 (https://energy.ec.europa.eu/system/files/2014-11/2014_article4_ro_romania_0.pdf). Currently, the building is considered as a structure in a continuous evolution, which in time through maintenance, rehabilitation and modernization works will meet the requirements expressed by the user. The case study presented in the paper presents an analysis from the point of view of improving the energy efficiency, reducing the energy requirement in a building using passive energy-saving measures, that is, the additional thermal insulation of an element of the building envelope. The materials selected for this research are: expanded polystyrene, basaltic mineral wool and cellulose fibres.

Thermal analysis of sustainable and micro-filler Basalt reinforced polymer biocomposites for lightweight applications

For the past ten years, there has been a trend toward strengthening polymer composites with the help of natural fibers derived from plant and animal sources, which has led to ecological imbalance. Hence, to maintain the ecological balancing factors, the researchers and industrial experts are concentrating on the reinforcement of naturally available mineral materials in polymer products to minimize the polymer percentage and boost the economic feasibility of products with lightweight properties. In fact, incorporating basalt mineral into different polymer matrices is a highly creative notion that might open up some very interesting, uncharted territory. Basalt helps to create a pollution-free environment and balance ecological challenges by reducing the polymer ratio in the objects without many changes in their core properties. Basalt is desirable because of its outstanding thermal and mechanical characteristics, simplicity of processing, affordability, and lack of toxicity. Concerning these points, the current study aims to fabricate mineral particles (basalt)-reinforced (30 wt%) different polymers (synthetic epoxy, bio-epoxy, polyester, vinyl ester, polylactic acid, polypropylene, and high-density polyethylene) composite for lightweight thermal applications. The casting technique was used for the fabrication of thermoset polymer composites, whereas compression molding was employed to fabricate thermoplastic composites after an internal mixing process. The fabricated composites are subjected to thermogravimetric, thermomechanical, and dynamic mechanical analysis to analyze the thermal stability of the resultant composites. The Thermogravimetric analysis revealed that most of the samples exhibited good thermal stability with the addition of 30 wt% basalt fillers. As a result of moisture content as well as certain volatile compounds, if any, only a minimal weight loss in the range of 30 °C to 130 °C was seen at the early phase of heating for all neat and composite samples. The Thermomechanical analysis findings showed that basalt reinforcement at 30 wt% in synthetic epoxy, Polylactic acid, Polypropylene, and High Density Poly Ethylene polymers causes a reduction in dimensional variations up to 70 °C. This is because the basalt particles, particularly in the hard glassy area, limit the passage of molecules at lower temperatures. The higher stiffness of the basalt particles has significantly contributed to the viscoelastic properties of all the thermoset and thermoplastic composites. Because of the extreme closeness and thick packing of the components, which are in a dormant condition, the glassy areas in particular have a greater storage modulus. Based on these outcomes, these basalt-reinforced composites can be employed for lightweight thermal applications, which have the advantage of economic and eco-friendly features.

WNMS: A New Basaltic Simulant of Mars Regolith

The use of planetary regolith can be explored via the utilization of simulants. The existing Martian simulants have differences due to varying source materials and design parameters. Additional simulants are needed because the few available simulants do not replicate the compositional diversity of Martian regolith. This study discusses the development of a low-cost construction simulant of Mars. The area of Winder Nai in Pakistan was selected for field sampling of basalt because of local availability and easy access. The dust was produced from rock samples through mechanical crushing and grinding. The physical properties, composition, mineralogy, and surface morphology were evaluated via geotechnical tests, Energy Dispersive X-ray (EDX) spectroscopy, X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM), respectively. The designed simulant has a well-graded particle size distribution with a particle density and bulk density of 2.58 g/cm3 and 1.16 g/cm3, respectively. The elemental composition of Winder Nai Mars Simulant (WNMS) is within ±5 wt% of the Rocknest and the average Martian regolith composition except for SO3. For SiO2, Al2O3, and Fe2O3, WNMS has a good match with the Martian regolith. The content of CaO and TiO2 in WNMS is higher than, and content of MgO is lower than, the average Martian values. The rock can be classified as basalt based on the Total Alkali Silica (TAS) diagram. XRD spectrum indicates the occurrence of plagioclase and pyroxene as the main signature minerals of basalt. The particle morphology of WNMS is angular to subangular, and the simulant indicates the presence of 3.8 wt% highly paramagnetic particles. The volatile loss is 0.25 wt% at 100 °C, 1.73 wt% at 500 °C, and 3.05 wt% at 950 °C. The composition of WNMS, basaltic mineralogy, morphology, magnetic properties, and volatile content are comparable with MMS-2 and a few other simulants.

Reactivity of Basaltic Minerals for CO2 Sequestration via In Situ Mineralization: A Review

The underground storage of CO2 (carbon dioxide) in basalt presents an exceptionally promising solution for the effective and permanent sequestration of CO2. This is primarily attributed to its geochemistry and the remarkable presence of reactive basaltic minerals, which play a pivotal role in facilitating the process. However, a significant knowledge gap persists in the current literature regarding comprehensive investigations on the reactivity of basaltic minerals in the context of CO2 sequestration, particularly with respect to different basalt types. To address this gap, a comprehensive investigation was conducted that considered seven distinct types of basalts identified through the use of a TAS (total alkali–silica) diagram. Through a thorough review of the existing literature, seven key factors affecting the reactivity of basaltic minerals were selected, and their impact on mineral reactivity for each basalt type was examined in detail. Based on this analysis, an M.H. reactivity scale was introduced, which establishes a relationship between the reactivity of dominant and reactive minerals in basalt and their potential for carbonation, ranging from low (1) to high (5). The study will help in choosing the most suitable type of basalt for the most promising CO2 sequestration based on the percentage of reactive minerals. Additionally, this study identified gaps in the literature pertaining to enhancing the reactivity of basalt for maximizing its CO2 sequestration potential. As a result, this study serves as an important benchmark for policymakers and researchers seeking to further explore and improve CO2 sequestration in basaltic formations.

Basalt mineral surface charge and the effect of mineralization on its colloidal stability: Implications of subsurface CO2 storage

Global concern over climate change caused by greenhouse gas emissions has received and is still receiving a lot of attention. Companies and nations have committed to reducing their carbon footprint to halt the consequences, and work is being done to create long-term strategies for CO2 usage. One of these goals is to use the CO2 that has been captured to make chemicals or to use it to make waste that can be buried or safely disposed of. One such endeavours is CO2 mineralization, which has been suggested as a method of CO2 utilization. It entails the creation of carbonates by the interaction of a fluid that contains CO2 with cations that are found in brines or rocks. However, the mineralization process is a protracted one, and until recently it was not believed that it could be completed in less than two years. Furthermore, little research has been done on how mineralization affects the electrokinetic and surface chemistry of cation-bearing rocks like basaltic rocks. Therefore, this study assesses how mineralization (carbonate precipitation) affects the colloidal and electrokinetic characteristics of basaltic rock.According to the study's findings, the electrical double layer (EDL) effect and protonation of the silanol group function as the two main controlling mechanisms of charge formation in the basaltic rock. More so, the rock sample is negatively charged over a range of pH and colloidally stable in freshwater. However, its colloidal stability is decreased in brines, and the EDL effect and potential determining ions (H+ and OH–) dominate its charge development. Additionally, different precipitates have distinct effects on the electrokinetic characteristics of basaltic rock, with the MgCO3 and FeCO3 precipitation having a more notable impact than the CaCO3 precipitation. Furthermore, at pH values of 3 – 4 (CO2 storage pH) in both freshwater and sweater environments, basaltic rocks exhibit near zero or low surface charge values indicating weak adhesion force. Thus, the question of if the near pH values of 2, can be considered as higher values of surface charge is observed in some cases. These findings raise questions about the structural integrity of basaltic rock, which has been touted as a prime candidate for the mineralization process due to its reactive nature, particularly in the case of colloidal stability after the mineralization process. The results of this study further provide new insight into the optimization of the mineralization process, which is dependent on the structural and petrophysical characteristics of the rocks and reservoirs that provide the cations for the process.

Erosion mode and history of Eastern Adamaoua landscapes (Cameroon): Superimposed lateritic weathering of granites and basalts

Landscapes of eastern Adamaoua highlands have been shaped by successive weathering and erosion processes of Pan-African crystalline rocks and Neogene volcanics cover. Basalts have outpoured through major inherited structural discontinuities mostly in shallow incisions of lateritic pediplains previously shaped on the granitic basement. That has resulted in formation of a singular composite lateritic weathering profile on basalt superimposed to a truncated profile composed of mottled clays and saprolite on granite. The composite profile studied here is little evolved, mostly kaolinised on granite while basalt is weakly to moderately lateritised owing to differences in silica and iron oxide contents of the two contrasted parent rocks. During lateritic weathering, Cu, Ni, and Co are enriched in profile on granite but depleted on basalt, while Zr/Ti is relatively constant. Behavior and fractionation of REE are comparable except higher Eu* and Ce* anomaly on granite profile than on weathered basalt, owing to parent minerals differences, mostly feldspars in granite versus plagioclase and Fe-Mg minerals in basalt. The contrast in Eu* is also linked to differences in the Index Of Laterization (IOL) in weathered horizons of the two parent rocks. Beyond quite classical litho-dependent geochemical differences in the composite profile, persistence of per-humid climate and good drainage over Neogene have sustained rock-weathering and local surface erosion processes upon volcanic outpours and their contact surface with pediplains formed on Pan-African granitoids of Adamaoua highland.

Experimental study on plagioclase dissolution rates at conditions relevant to mineral carbonation of seafloor basalts

Over the last two decades, all scenarios projected to achieve the goals of the Paris climate agreements have required negative emissions of greenhouse gases. Mineral carbonation of basalt is a promising negative emission technology for long-term storage of carbon dioxide (CO2). During mineral carbonation, dissolved CO2 is converted into solid carbonate minerals through reaction with silicate minerals. Plagioclase feldspars are the most abundant primary silicate minerals in basalts readily available for water-rock interactions. Despite numerous recent laboratory studies, the rate at which plagioclase dissolution occurs under the required conditions for large-scale carbon storage remain poorly constrained. In this study, we present new flow-through experiments quantifying the apparent dissolution rates of plagioclase in sodium chloride solutions with elevated concentrations of dissolved CO2 at temperatures between 25 °C and 125 °C and pressure of 200 bars. The mildly acidic conditions produced by carbonic acid yield apparent rates that are slower than those previously reported for plagioclase under more acidic conditions and alkaline conditions. We used these apparent rates to develop new temperature-dependent rate equations for plagioclase dissolution in solutions buffered by carbonic acid:kCa=10−9.811±0.664exp−22.27±2.08R∙1T−1TrkSi=10−10.334±0.445exp−33.99±1.40R∙1T−1Trwhere k is the rate constant (mol m−2 s−1) at any temperature (T in K), R is the universal gas constant (8.3145 KJ/mol/K)and Tr is the reference temperature (298.15 K). Utilizing the new Ca rate equation into a geochemical model, we estimated that the reaction time to achieve carbonate saturation in a closed system with high CO2 ranges from a few days to a few years depending on water-to-mineral ratios. These results could have significant implications for required monitoring on projects or achieving gigaton-scale of carbon storage and mineralization annually, where planned injection rates of million(s) of tons of CO2 per well per year could overwhelm aquifer alkalinity, lower pH, and reduce the efficiency of carbon mineralization.

Study on wastewater treatment based on local minerals

In this article, the HMP-3 wastewater treatment process with natural minerals (vermiculite, zeolite, dolomite, saponite, shungite, bentonite, basalt minerals), rice husk, 1% NaClO (sodium hypochlorite) and 3% H2O2 (hydrogen peroxide) solutions will be discussed. According to the research results, the activation of samples used for wastewater treatment in the form of 1% sodium hypochlorite solution and 3% hydrogen peroxide solution shows high efficiency.

ФИЗИКО-ХИМИЧЕСКИЕ УСЛОВИЯ ОБРАЗОВАНИЯ СОВРЕМЕННЫХ БАЗАЛЬТОВ ВУЛКАНА ЛОКОН, ОСТРОВ СУЛАВЕСИ (ТИХИЙ ОКЕАН): ДАННЫЕ ПО РАСПЛАВНЫМ ВКЛЮЧЕНИЯМ

We studied phenocrysts and melt inclusions in order to evaluate physical and chemical conditions of petrogenesis of the Sulawesi Island (southwestern Pacific) basalts. The compositions of the phenocrysts of clinopyroxene and plagioclase hosted by basalts of the Lokon volcano indicate two types of melts: primitive and differentiated. Primitive magmas produced high-anorthite plagioclases that are absent from the Lokon volcano andesites. The second type of melts produced compositionally similar clinopyroxenes and plagioclases of both basalts and andesites. Similarities in compositions of homogeneous glasses of melt inclusions in minerals from the Lokon volcano and other volcanoes of the Sulawesi Island and the SW Pacific suggest similar P-T conditions for the formation of magmatic systems. In particular, the data on inclusions demonstrate that basaltic magmas of the Lokon and Soputan volcanoes are primitive melts (SiO2 = 48.2–51.5 wt.% and MgO up to 8 wt.%), which is consistent with the content of other oxides. These inclusions plot at the beginning of the «andesitic» trends in variation diagrams. Accordingly, these melts could be primary melts for the development of the entire magmatic system that formed andesitic to basaltic effusive rocks of the Tondono caldera and the Lokon and Soputan volcanoes. Based on the compositions of both, melt inclusions and their host minerals in Lokon basalts, we concluded that clinopyroxene phenocrysts crystallized at two levels: 20.6–14.5 km (1150–1130°С) and 13–6 km (1145–1105°С), and plagioclase phenocrysts crystallized at 1160–1120°С. In general, our data on melt inclusions and phenocrysts indicate fundamental differences in the PTX parameters of the magmatic systems that formed basalts and andesites of the Sulawesi Island. The basalt-hosted clinopyroxene phenocrysts crystallized from compositionally stable melts at a slightly decreasing temperature with a significant pressure drop during magma ascent. Phenocryst crystallization in andesites proceeded differently: with delays at constant pressures in deep intermediate chambers and a significant drop in temperature, which facilitated the processes of fractionation and evolution of melts.

Effect of basalt fiber on properties of asphalt and asphalt mixture

Asphalt mixture is the surface material of flexible pavement and semi-rigid pavement. It directly bears the influence of climate conditions and traffic load, and is prone to aging and fatigue damage. Therefore, using reinforcing agent to improve the performance of asphalt mixture is the long-term goal of researchers.This paper aims to study the effect of basalt fiber on asphalt viscosity and mechanical properties of asphalt mixture. Firstly, by testing the basic properties of asphalt binder with different fiber content, the viscosity characteristics of fiber + asphalt composites are analyzed by using the modified Einstein viscosity equation. The research shows that basalt fiber has obvious toughening effect on asphalt, and the penetration and softening point indexes are suitable to evaluate the viscosity properties of fiber + asphalt composites.Secondly, the effects of different fiber content on the water stability and splitting tensile strength of asphalt mixture are analyzed. The results show that the maximum content of basalt fiber should not be greater than 0.4%; With the increase of fiber content, the splitting strength of asphalt mixture increases, but the increase is not obvious when the content is &gt; 0.30%, while the stiffness modulus continues to increase, indicating that the deformation resistance of asphalt mixture is enhanced after adding fiber. Based on the micromechanics theory of composite materials, the basic principle of basalt mineral fiber improving the strength performance of asphalt mixture is explained. The research shows that basalt mineral fiber can significantly improve the performance of asphalt mixture.