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Geological samples are inherently multi-scale. Understanding their bulk physical and chemical properties requires characterization down to the nano-scale. A powerful technique to study the three-dimensional microstructure is X-ray tomography, but it lacks information about the chemistry of samples. To develop a methodology for measuring the multi-scale 3D microstructure of geological samples, correlative X-ray micro- and nanotomography were performed on two rocks followed by scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS) analysis. The study was performed in five steps: (i) micro X-ray tomography was performed on rock sample cores, (ii) samples for nanotomography were prepared using laser milling, (iii) nanotomography was performed on the milled sub-samples, (iv) samples were mounted and polished for SEM analysis and (v) SEM imaging and compositional mapping was performed on micro and nanotomography samples for complimentary information. Correlative study performed on samples of serpentine and basalt revealed multiscale 3D structures involving both solid mineral phases and pore networks. Significant differences in the volume fraction of pores and mineral phases were also observed dependent on the imaging spatial resolution employed. This highlights the necessity for the application of such a multiscale approach for the characterization of complex aggregates such as rocks. Information acquired from the chemical mapping of different phases was also helpful in segmentation of phases that did not exhibit significant contrast in X-ray imaging. Adoption of the protocol used in this study can be broadly applied to 3D imaging studies being performed at the Advanced Light Source and other user facilities.

Basalt fiber-reinforced composite (BFRC) is extensively used in various fields such as rail transportation and aerospace. However, how to design the structure of BFRC to optimize its impact resistance remains a great challenge. Herein, inspired by the double-twisted Bouligand structure of coelacanth scales, a biomimetic BFRC is prepared. Significantly, the peak impact force of double-twisted BFRC (DT-BFRC) is 3408.12 N, which increases by 48.56% compared with unidirectionally laminated BFRC (UL-BFRC). The maximum residual elastic modulus of DT-BFRC reaches 7.88 J, which is 236.75% higher than that of UL-BFRC. This work offers a promising way to efficiently develop impact resistant BFRC. [ABSTRACT FROM AUTHOR]

This study presents a detailed flow-by-flow petrographic modal description and major element data integrated into the stratigraphic framework for the central part of the southeastern Ethiopian plateau (the Chole Section). The stratigraphic data are placed in the context of the regional stratigraphic framework and correlated with existing geochronology of the province, allowing us to estimate the timing and duration of volcanic activity in the area. Based on petrographic variations and physical volcanological features, the Chole section is divided into: (1) lower basalt; (2) middle basalt; and (3) upper basalt. The phase assemblages and major element data show that the lower and upper basalts underwent possible fractionation involving olivine, plagioclase, and augite. In contrast, the middle basalt equilibrium phase and major element data exhibits low-degree fractionation involving olivine, clinopyroxene, and orthopyroxene at greater depths. The stratigraphic position and the petrographic data suggests, the lower and middle basalt successions likely correlate with the Oligocene to Early Miocene basaltic succession (28–15.5 Ma) of the southeastern Ethiopian volcanic province. The presence of several volcanic hiatuses and the decrease in flow thickness in the middle basalt suggest a waning of magmatic activity during this period. The upper basalt of the Chole section correlates with the upper Miocene basalt of the southeastern volcanic province (15.5–11 Ma). From this, we determine that volcanic activity in the southeastern Ethiopian volcanic province is well constrained within the broader tectono-magmatic framework of the East African volcanic province. [ABSTRACT FROM AUTHOR]

The cumulative acoustic emission quantity and energy released when the columnar jointed basalts (CJBs) reach their strength under compression are important theoretical foundations for studying the mechanical characteristics of CJBs and for relevant engineering monitoring and reinforcement. Combining meso-mechanics of damage, statistical strength theory, and continuum mechanics, based on the DIC-improved RFPA digital image processing, the images of CJBs with different model sizes are constructed and transformed into heterogeneous finite-element mesh models to investigate the strength and deformation characteristics, fracture patterns, and energy progression laws of CJBs under uniaxial compression and lateral pressure conditions. The impacts of diverse factors on micro-crack quantity index (MCQI) and micro-crack energy index (MCEI) are analyzed. Furthermore, the main sensitive factors are identified through sensitivity analysis, establishing their fitting models. This study shows that the CJBs with larger joint elastic moduli (or rock constitutive relations tending towards brittleness) release MCEIs earlier. In addition, the CJBs owning larger column diameter may discharge MCEIs earlier, but with lower values, which is attributed to the scenario that under lateral pressure condition, the failure mechanism of large-diameter CJBs is mainly controlled by a small number of damage fracture zones. Moreover, the CJBs with joint constitutive relation tending towards plasticity (or greater rock homogeneity / stronger constrained state of rock mass) liberate MCEIs relatively late. Under lateral pressure condition, large-sized specimens with weaker boundary constraints have higher MCEIs because they are more prone to damage, and their larger size results in more damaged elements. Considering the occurrence sequence and magnitude of micro-cracks in CJBs, the factor sensitivity evaluation models for energy characteristics are constructed. Under lateral pressure condition, the main sensitive factors affecting MCEIs are the constrained state of rock mass, joint mechanical property, and rock heterogeneity. Conversely, the factors such as joint constitutive relation, column diameter, and meso-rock constitutive relation are less sensitive. The main sensitivity factor models for the MCEIs of CJBs can provide theoretical framework for engineering monitoring, reinforcement, operation, and maintenance of CJB engineering projects. Highlights: The larger the model size, the earlier the micro-crack quantity index and micro-crack energy index may appear on the strain axis. Under the lateral pressure condition, although generally a larger model size results in a higher micro-crack energy index, there are the exceptions. The main sensitive factors for the micro-crack quantity index are joint constitutive relation, rock mass constraint state, and column diameter, etc. The main sensitive factors affecting micro-crack energy index are the rock mass constraint state, joint mechanical property, and rock heterogeneity, etc. [ABSTRACT FROM AUTHOR]

The elastic modulus of basalt is a significant engineering parameter required for many projects. Therefore, a total of 137 datasets of basalts from Digor-Kilittasi, Turkey, were used to predict the elastic modulus of intact rock (Ei) for this study. P wave velocity, S wave velocity, apparent porosity, and dry density parameters were employed as input parameters. In order to predict Ei, seven different models with two or three inputs were constructed, employing four different machine learning methods such as Support Vector Machine (SVM), Gaussian Process Regression (GPR), Ensembles of Tree (ET), and Regression Trees (RT). The performance of datasets, models, and methods was evaluated using the coefficient of determination (R2), Root Mean Squared Error (RMSE), Mean Squared Error (MSE), and Mean Absolute Error (MAE). This study presented and analyzed the performance of four machine learning methods. A ranking approach was employed to determine the best performing method and dataset. Based on these evaluations, all four machine learning techniques effectively estimate the value of Ei. While they can be used as an appropriate choice for estimating the elastic modulus of basaltic rocks, the ET approach appears to be the most successful method. However, the performance of the GPR is the worst according to model assessments. The average R² values for Model 1 through 7 of the ET method for the five test datasets are 0.97, 0.93, 0.89, 0.97, 0.91, 0.99, and 0.99, respectively. The the average R2 values for GPR from Models 1 to 7 for the five test datasets are 0.73, 0.55, 0.69, 0.48, 0.47, 0.73, 0.56, respectively. An additional indication that the ET performed better than all the other methods was the Taylor diagram, which made it simple to determine how well the model predictions matched the observations. Furthermore, these findings validate the performance of the machine learning techniques employed in this study as valuable instruments for future investigations into the modeling of complex engineering issues. The results of this study suggest that machine learning algorithms can help reduce the need for high-quality core samples and labor-intensive procedures in predicting the elastic modulus of basaltic rocks, resulting in time and cost savings. [ABSTRACT FROM AUTHOR]

Compressional stresses from the basalt basins on the lunar are responsible for the formation of wrinkle ridges in lunar mare basalts. According to the wide angle multispectral camera (WAC) mosaic image, we selected 62, 75, 73, and 58 single wrinkle ridges in Mare Imbrium, Mare Serenitatis, Mare Fecunditatis, and Mare Tranquillitatis, respectively, for this paper. Several topographic profiles near the midpoint of each wrinkle ridge are generated to measure the maximum displacement (D max ) and height of the wrinkle ridges using digital elevation model (LOLA) data. After that, we create 2D plots of displacement-length (L) for the ridge population in the four Maria and compare the results. A linear fit method derives the D max / L ratios (γ) from the D-L data. We calculated the contractional strains in each mare area based on the cap D sub m a. x over cap L data. Moreover, each mare's gravity pattern, mare thickness, and formation age are also presented. The ridges in Mare Imbrium and Mare Serenitatis have a higher γ value (1.83 × 10−2 and 1.98 × 10−2) than the ridges in Mare Fecunditatis and Mare Tranquillitatis, which have γ values of (1.67 × 10−2 and 1.75 × 10−2). Finally, the contractional strains (ε) in Mare Imbrium, Mare Serenitatis, Mare Fecunditatis, and Mare Tranquillitatis are estimated to be 0.23 %, 0.41 %, 0.39 %, and 0.18 % (considering 25° is the fault plane dip θ), respectively. The maximum values of the free-air gravity anomalies in Mare Fecunditatis range from −30 to 250 mGal, while minimum gravity anomalies in Mare Serenitatis range from −80 to 140 mGal. Mare Imbrium, Mare Serenitatis, Mare Fecunditatis, and Mare Tranquillitatis have an average thickness of 300 m, 910 m, 652 m, and 760 m, respectively. Furthermore, the Mare Imbrium ridge group is older than the Lunar Wrinkle Ridges in Mare Serenitatis. Mare Tranquillitatis ridge group formation takes longer than Mare Imbrium ridge group formation. Therefore, we believe that it has thicker basaltic units, a longer wrinkle ridge formation time, and higher gravity anomaly than the Mare Imbrium and Mare Serenitatis basins, even though the formation of the Mare Tranquillitatis and Mare Fecunditatis basins occurred earlier. [ABSTRACT FROM AUTHOR]

Basalt is a widely used raw material for tool manufacture at prehistoric sites, but a unified methodology for assessing how hominfins used basalt in prehistory is lacking. A comprehensive experimental investigation of basalt tools is, thus, necessary to establish a reliable methodological framework that can be used to explore the functional properties of archaeological basalt assemblages. The aim of this study is to contribute to the development of a methodological framework for the analysis of use-wear on basalt tools. Basalt, characterised by its distinct mechanical and structural properties and unique response to mechanical stress, requires specialised treatment and investigation. To address this, our basalt varieties were characterised using SEM–EDS analysis. Sequential experiments were conducted, using the experimental basalt tools in different activities, including butchery, hide, bone and woodworking to determine use-wear formation patterns. Subsequentially, various analytical tools, including optical and scanning electron microscopes, were used to analyse macro- and micro-wear traces on basalt. Our results provide useful information on methodological aspects of use-wear formation on basalt. The inclusion of detailed cleaning and experimental protocols enhanced the robustness of our methodology. Furthermore, the combined utilisation of various microscopes enabled to compile a comprehensive and complementary information on such a complex raw material such as basalt and to characterise thoroughly the diagnostic features of the micro-wear traces (e.g. edge damage, rounding, polish). [ABSTRACT FROM AUTHOR]

Electrical resistivity imaging survey was carried out at the warm spring site in Kasane, northwest Botswana, to investigate the subsurface distribution of geological structures and how they influence the existence of the warm spring. This investigation was carried out along eight 480-m-long parallel profiles with an electrode spacing of about 10 m and 50 m line spacing. We used a Pole–dipole electrode array to acquire the data. The data inversion employed in this study was based on the smoothness constrained nonlinear least-square inversion algorithm. 2D data inversion for all the eight 2D datasets was performed, and the eight 2D datasets were then collated into a single 3D data file before performing a 3D data inversion. The resultant 2D inversion models display the variation of electrical resistivity beneath the respective profiles; whereas, the resultant 3D models show the distribution of electrical resistivity in both the lateral and vertical directions. The 2D inversion results revealed two distinct anomalies with low resistivity values, e.g., < 46.2 Ω m of the topmost layer indicating the presence of silty clays and relatively high resistivity material with resistivity values exceeding 249.3 Ω m, which was attributed to basalts. Also observed in the 2D inversion results are low-intermediate resistivity zones of about 46.2 Ω m extending to greater depths beyond the boundaries of the models, which are attributable to the existence of fluid-filled fractures/faults. The 3D inversion results resolved a laterally extensive high-resistivity basaltic unit, two NE–SW-trending vertical/near-vertical low-resistivity features which are attributable to fluid-filled fractures or faults, and a broad low-resistivity zone occurring beneath a depth of 40 m on the southeastern side of the study area, which is likely to be indicating part of the geothermal reservoir. The low-resistivity vertical/near-vertical features observed in this study are likely to be enabling the flow of geothermal fluids, and the high resistivity basaltic unit acts as a caprock overlying the reservoir. [ABSTRACT FROM AUTHOR]

Basalt fiber–reinforced polymer (BFRP) is widely used to reinforce concrete due to its high strength, lightweight nature, good corrosion resistance, and low cost. Previous studies have shown that the double-helix BFRP macrofiber has better bond behavior with concrete compared with other types of BFRP fibers. This is attributed to its irregular geometry. The bond-slip behavior between double-helix BFRP macrofiber and concrete is further numerically studied in this study. The corresponding finite-element model is established, and the accuracy of the numerical method is validated by the experimental results based on fiber-matrix pullout tests. The effects of twisted pitches, bundle numbers, and cross-section shapes of the fiber on the bond-slip behavior are extensively investigated and discussed. It is shown by the numerical results that the bond stress and energy-dissipating capacity increase with the decrease of twisted pitches (30, 20, 10, and 5 mm). The bond stress of the fiber with a twisted pitch of 5 mm can be increased by 17.0% at most compared with the fiber with a twisted pitch of 30 mm. Furthermore, it is found that the double-helix BFRP fiber has higher bond stress than the fiber with three or four bundles, with corresponding increases of 11.9% and 16.9%, respectively. [ABSTRACT FROM AUTHOR]

Tapered beams are characterized by varying moments of inertia along their span, commonly the pier cap configuration used in bridge construction. This study presents the shear behavior of tapered beams reinforced with basalt fiber–reinforced polymer (BFRP) bars through experiments and analyses. Eight BFRP beams were tested to explore the influence of changing inclination angles and the presence of BFRP stirrups. These beams were divided into two groups, each consisting of four beams: one control straight beam and three tapered beams with different tapered angles. The first group was without shear reinforcement, while the second group was reinforced with BFRP stirrups. Results revealed that increasing tapered angles decreased the shear strength of BFRP tapered beams without stirrups but increased it in beams with BFRP stirrups. The analytical part proposed equations to estimate the shear strength of BFRP tapered beams, with findings indicating conservative estimations consistent with experimental data trends. [ABSTRACT FROM AUTHOR]

Purpose: Food production is set to double by 2050 to feed the increasing world population. This poses a global challenge to minimise environmental impacts from intensified production and use of chemical fertilisers. The study investigates whether basalt rock dust fertiliser can be an environmentally sustainable close substitute to expensive conventional rock-derived P and K fertilisers. Method: The study uses the attributional life cycle assessment method to estimate and compare 15 environmental impacts between basalt rock dust fertiliser, a potential source of phosphorus (P) and potassium (K), and five widely used industrial P and K fertilisers. In addition, we model hypothetical basalt substitution rates for PK fertilisers to highlight potential ecological savings in terms of carbon capture. Results: Basalt rock dust fertiliser has minimal embodied environmental impacts across all 15 impact categories, including global warming, compared to industrial P and K fertilisers. Conclusion: Our results suggest that transitioning to milled basalt as a natural geo-fertiliser to support food production may help address several UN Sustainable Development Goals such as 'Responsible consumption and production' and 'Climate Action and Zero Hunger'. [ABSTRACT FROM AUTHOR]

Lunar mare basalts represent melting of mantle material, buoyant ascent in dikes, and eruption onto <20% of the surface. Global mare distribution is distinctly asymmetrical, with a paucity on the farside, plausibly interpreted to be related to thicker farside low‐density crust inhibiting buoyant magma rise to the surface. Challenging this hypothesis is the presence of the huge, ancient farside South Pole‐Aitken (SPA) basin, site of the thinnest crust and deepest depression observed on the Moon. We hypothesize that an oblique impact stripped the farside crust within the SPA basin, permitting early mare basalt emplacement as cryptomaria due to thin/absent crust. However, removal of the SPA thermally insulating megaregolith/crust accelerated lithosphere thickening beneath the basin. This deepening rheological barrier inhibited buoyant rise of mantle diapirs below SPA, resulting in early abatement of mare basalt extrusions compared to the nearside, and retention of the deep, underfilled SPA impact basin observed today. Plain Language Summary: The cause of the observed asymmetry in nearside/farside mare basalt distribution (nearside ∼15% of the surface, farside ∼1%) has been attributed to differences in crustal thickness and the magma buoyancy at the base of the thicker crust, but this single factor is challenged by the presence of the ancient very deep SPA basin (average ∼5 km), significantly underfilled by mare basalts compared to the nearside. We examine the effects of the formation of the giant (∼2,300 km) SPA basin in removing the insulating megaregolith/crust, and show that it could first result in rapid cryptomaria emplacement due to near‐absent crust, accompanied by enhanced heat loss within the basin, and formation of anomalously early thick sub‐SPA lithosphere, inhibiting its mare filling due to a rheological barrier to basaltic magma eruptions, analogous to that which occurs later in lunar history on the lunar nearside. Key Points: The nearside‐farside asymmetry in mare basalt volcanic deposits has been attributed to thicker farside crust inhibiting eruptionChallenging this hypothesis is the very deep, thin‐crust ancient SPA impact basin, significantly underfilled by mare basaltsAfter SPA impact‐removal of insulating crust, sub‐SPA lithosphere thickens anomalously early, inhibiting mare fill following cryptomaria [ABSTRACT FROM AUTHOR]

Helium reservoirs, as an indispensable and scarce strategic resource, can be categorized into two primary origins: crust- and mantle-sourced. Understanding the mechanisms of its formation and accumulation is a crucial challenge in helium exploration. Previous work on helium exploration has mainly focused on crustal helium, while mantle-sourced helium-rich reservoirs have been overlooked. Helium reservoirs with both a crustal and a mantle source exhibit higher helium abundance than that of crustal helium reservoirs and are sporadically distributed in Neogene basins worldwide, but their formation and evolution is poorly understood. In Eastern China, several Neogene basins preserve high quality crust/mantle helium-rich reservoirs, and in this study, we use the Subei Basin as a case study to investigate processes controlling He accumulation and storage. The helium reservoirs can be classified into two types based on the lithological nature of the structural traps: sand reservoir with mud cap and basalt reservoirs with mud cap. The main controlling factors for the formation of crust–mantle helium-rich reservoirs include deep-seated faults, magmatic activity, and mineralization of mantle-derived CO2. Deep-seated faults, along with their associated strike-slip faults, serve as favourable pathways for mantle-derived helium migration and magma upwelling. Magmatic activities serve as the material source for mantle-derived helium as well as the carrier medium in the migration of mantle-derived volatiles. The presence of well-developed sandstone and basalt reservoirs, along with mudstone cap rocks, and the dissolution and mineralization caused by mantle-derived CO2 are important factors in helium accumulation and preservation. [ABSTRACT FROM AUTHOR]

This research aims at systematically evaluating the properties of SMA-13 asphalt mixture reinforced by several fiber additives including flocculent lignin fiber (FLF), granular lignin fiber (GLF), chopped basalt fiber (CBF), and flocculent basalt fiber (FBF). Firstly, the thermal stability, moisture absorption, and oil absorption property of these fiber additives were analyzed. Secondly, the property of SMA-13 reinforced using four types of single fibers and two kinds of composite fibers (FLF + CBF and FLF + FBF) was comprehensively analyzed. Specifically, the high-temperature performance was evaluated using the uniaxial penetration test and the rutting test, the medium-temperature anticracking property was evaluated using the IDEAL-CT test, the low-temperature property was analyzed using the beam bending test, and the water stability was studied by the freeze–thaw splitting test. Thirdly, the dynamic mechanical response of different-fibers-modified SMA-13 was evaluated using the uniaxial compression dynamic modulus test. Finally, correlation analysis between the results of dynamic modulus and the high-, medium-, and low-temperature mechanical performance was carried out. The research results reveal that the stability of CBF and FBF under thermal action is better than that of GLF and FLF, and FBF shows the best thermal stability. The oil absorption property of FLF is better than that of GLF, followed by FBF and CBF. The comprehensive mechanical properties of CBF- and FBF-reinforced SMA-13 are better than those of FLF- and GLF-modified SMA-13. CBF can better reinforce the mechanical property of SMA-13 under low and medium temperature, while FBF can better reinforce the performance of SMA-13 at high temperature. FLF/CBF- and FLF/FBF-composite-modified SMA-13 show better high-temperature mechanical performance than that of the single-fiber-reinforced mixture, and FLF has some negative impact on the properties of FLF/FBF-composite-modified SMA-13 at low temperature. Fibers have no significant influence on the water stability of the mixtures. Meanwhile, the linear correlation between the mechanical performance of all the fiber-reinforced SMA-13 and the dynamic modulus result is good. [ABSTRACT FROM AUTHOR]

Apatite is ubiquitous in lunar samples and has been used widely for estimating volatile abundances in the lunar interior. However, apatite compositional and isotopic variations within and between samples have resulted in varying and ambiguous results. Understanding apatite petrogenesis will help with both identifying the appropriate composition for volatile estimation and interpreting isotopic variations. Here we report a comprehensive petrogenetic investigation of apatite in Chang'E-5 (CE5) basaltic sample CE5C0800YJYX013GP. Apatite displays both intra-grain and inter-grain compositional variations with F and Cl contents falling in the ranges of 0.97–2.47 wt% and 0.24–1.09 wt%, respectively. These apatite compositions show relatively low F and high Cl characteristics in comparison to apatites of Apollo high-Ti and low-Ti mare basalts, but are similar to those reported for lunar meteorites LAP 04841 and MIL 05035. We discern three zoning profiles: fractional crystallization (FC)-dominated, degassing-induced and a third indicated by REE-enriched cores, which are interpreted as representing different generations of apatite. FC-dominated zoning is characterized with decreasing F and increasing Cl and S contents from core to rim; while the opposite is true for the degassing-induced zoning. Regardless of the zoning patterns, apatite Cl and S contents display positive correlations, with S contents up to ∼ 3000 ppm, much higher than previous reports for Apollo samples (up to ∼ 600 ppm). We demonstrate that the fractional crystallization model proposed by Boyce et al. (2014) in combination with H 2 O degassing and high S contents in melt (likely at sulfide saturation) can explain these high Cl and S contents observed in CE5 apatite. Based on the core composition of the FC-dominated zoning profile, which has the lowest incompatible element concentrations, bulk F, Cl and H 2 O contents in the parental melt are estimated to be ∼ 72 ± 21, ∼43 ± 14 and ∼ 1576 ± 518 ppm, respectively. These estimates have lower F/Cl ratios than those measured in olivine-hosted melt inclusions from Apollo mare basalts. By adopting the petrogenetic model for CE5 basalt proposed by Su et al. (2022) , i.e., 10 % partial melting of a hybrid mantle source, followed by ∼ 30–70 % fractional crystallization (∼50 % for our sample), we estimate the F, Cl, H 2 O and S contents in the mantle source are in the ranges of ∼ 2.5–4.6, ∼0.7–1.4, ∼53–105 and ∼ 38–125 ppm, respectively, similar to estimates for both depleted Earth mantle and primitive lunar mantle. However, by adopting the model of Tian et al. (2021) , 2–3 % partial melting of a mantle source composed of 86 PCS+2% TIRL (PCS, percent crystallized solid; TIRL, trapped instantaneous residual liquid), followed by 43–88 % fractional crystallization, these estimates will be 5–10 times lower. To be certain whether the relatively low F and high Cl characteristics of CE5 apatite imply an enriched mantle source requires further evaluation of the petrogenetic models for CE5 basalt. [ABSTRACT FROM AUTHOR]

Diyarbakir province mean rock formation is basaltic due to its location. Basaltic parent rocks release much silt or clay when imposed to chemical or physical weathering. The soils are residual in origin. In other words, they formed in situ where the basaltic parent rocks exist. They were not transported by means of wind or water. In this research, firstly, the properties of Diyarbakir basaltic clays were investigated from literature. After that, one soil sample from Kayapinar vicinity has been taken to laboratory to find index properties. The values from two different locations which are obtained from literature and values which are obtained from laboratory were compared. The results indicated that the three samples from different locations showed roughly the same index properties. As per the results, the clay is high plastic (CH), and it has swelling potential. In this thesis, design parameters of posttensioned slabs on ground under different climatic scenarios were found. The widely used method for slabs on ground under swelling soils is the Post‐Tensioning Institute (PTI) method. In order to use this method, Thornthwaite moisture index is required. This index is used in geotechnical engineering to identify moisture flux boundary conditions for unsaturated soils and depth of active zone for expansive soils. This index has been found using water balance sheet tables for Diyarbakir. So as to find the future moisture index, water balance sheet tables have been formed finding the climate projection data for Turkey in literature. In this way, five moisture index values of Diyarbakir have been found for the current situation and with regard to representative concentration pathway (RCP4.5 and RCP8.5) scenarios for 2050. The parameters for the maximum differential swell (em) and the angular moisture change index (ym) for design procedure according to the PTI method were found for each moisture index. Results showed that the ym and em values increased when the Thornthwaite moisture index is reduced. Also results showed that the slab thickness is increased when moisture index is reduced. Considering the moisture index parameters for future values, Diyarbakir is likely to face arid climates in the future. [ABSTRACT FROM AUTHOR]

With increasing demand for high-performance materials in modern industry, lightweight, high-strength, and excellent thermal insulation materials have become a hot topic of research. Basalt fibers, due to their excellent mechanical properties and temperature resistance, are widely regarded as an ideal choice for reinforcing materials. This study aims to prepare basalt fiber-reinforced silica aerogels and conduct an in-depth study of its properties. Silica aerogel with a nano-porous structure was successfully prepared using the sol–gel process, and it was reinforced with basalt fibers. The study investigated the effects of different amounts of basalt fiber on the mechanical properties, thermal stability, and thermal insulation performance of the composite aerogels. The results show that the addition of basalt fibers significantly improved the compressive strength of the composite material while maintaining the low thermal conductivity characteristic of the aerogel. This study provides a new approach for the development of high-performance thermal insulation materials and lays the foundation for the application of basalt fibers in the field of aerogels. [ABSTRACT FROM AUTHOR]

S2‐glass fiber reinforced plastics (S2‐GFRP) and basalt fiber reinforced plastics (BFRP) have emerged as crucial materials due to their exceptional mechanical properties, and milling of composite materials plays an important role in achieving desired properties. However, they have proven challenges due to relative inhomogeneity compared with metals, resulting unpredictability in quality of milling operations. The objective of this work is to investigate the effect of cutting parameters, tool geometry and tool surface materials on the surface quality of composites using burrs as a metric. S2‐GFRP and BFRP composites were produced by the vacuum infusion method. Helical and straight flute end mills were manufactured from high‐speed steel (HSS) and carbide rounds, and half of them were coated with titanium nitride using reactive magnetron sputtering technique. Taguchi L18 orthogonal array is used to determine the effect of tool material, tool angle, coating, cutting direction, spindle speed, and feed rate on the machining quality of S2‐GFRPs and BFRPs with respect to burr formations. Milling experiments were conducted under dry conditions and then the burrs were imaged to calculate the total area and length. Statistical analysis was also performed to optimize the machining parameters and tool type for ensuring the structural integrity and performance of the final composite parts. The results showed that the selection of tool material has the most significant impact on the burr area and length of the machined surface. The novel image analysis allows to analyze the extent of the burr size with a desirable operation speed for industrial applications. Highlights: Aerospace grade S2‐Glass (S2‐GFRP) and basalt fiber reinforced plastics (BFRP) were manufactured.Carbide and HSS end mills were fabricated and coated with titanium nitride protective layer.FRPs were machined at various process parameters designed by Taguchi method.Distinctive image processing was firstly used to compute milling induced Burr area and length.Statistical analysis was performed to quantify the contribution of parameters and optimize milling. [ABSTRACT FROM AUTHOR]

Bimodal magmatism is characteristic of the geodynamic evolution of the Main Ethiopian Rift (MER), which is a reference area for the study of the processes leading to continental break-up before seafloor spreading. There are abundant emissions of basalts and rhyolites, which are in possible parent–daughter relationships. However, the P – T –H2O conditions of production and storage of the basaltic end member remain unclear. Crystallization experiments have been conducted on an alkali basalt from the MER to define its pre-eruptive conditions and shed light on the compositional evolution of derivative liquids and source conditions. The experiments were performed at 100 to 200 MPa, 975°C to 1080°C, varying H2O/CO2 ratios, corresponding to melt water contents of 1 to 5 wt %, at f O2 slightly lower than the Fayalite-Magnetite-Quartz (FMQ) solid buffer. Comparison between the petrological attributes of the starting rock and the experiments shows that the basaltic magma was stored at 150 to 200 MPa, 1050 ± 10°C, with 1 to 2 wt % H2O in melt, with f O2 near FMQ prior to eruption. Geochemical modelling shows that the corresponding mantle source contained about 0.1 wt % H2O, reflecting a metasomatized source. Extensive crystallization of such basalts produces SiO2-rich liquids, which are not yet peralkaline, however. This underscores that extreme fractionation (>90 wt %) is required in order to produce peralkaline derivatives from mildly alkaline basalts. This extreme fractionation and the water-rich nature of the starting basalt readily explain the H2O-rich condition of peralkaline rhyolites that have fueled caldera forming eruptions in the Rift. [ABSTRACT FROM AUTHOR]

Alkaline basalts produced in continental arcs should contain information different from the arc tholeiite-calc-alkaline-series magmas, and their origin could provide unique constraints on deep mantle composition and material cycling. However, due to their sparse occurrence, alkaline basalts in continental arcs have not been studied thoroughly, which hinders our understanding of the mantle diversity and subduction dynamics under continental arcs. In this study, we present new 40Ar/39Ar ages, major and trace elements, and Sr-Nd-Hf isotopic data for the International Ocean Discovery Program Site U1504 alkaline basalts in the continental arc developed on the South China Block (SCB). These alkaline basalts were generated at ca. 121 Ma and display typical oceanic-island basalt geochemical characteristics. Their relatively high eNd(t) (3.5-3.7) and low (87Sr/86Sr)i (0.7034-0.7040) and La/Nb (0.5-1.0) values suggest that they were mainly derived from an asthenosphere mantle source. Compared to alkaline basalts in the SCB inland, U1504 alkaline basalts exhibit lower K2O/Na2O, Zr/Sm, Zr/Y, eNd(t), and eHf(t) values, indicating the addition of minor sub-continental lithospheric mantle. The enrichment of Nb, Ta, light rare earth elements, and slight depletion of Zr, Hf, and Ti, as well as elevated Fe/Mn and Sm/Yb and low CaO, indicate that their mantle lithology was mainly garnet pyroxenite. Based upon these findings and previous studies, the garnet pyroxenite was probably formed by the interaction of upwelling asthenosphere with slab edges in the scenario of break-off of the Paleo-Pacific Plate, and such interaction diversified the mantle chemistry beneath continental arcs. In conjunction with other reported alkaline basalt data, it is proposed that the enriched asthenosphere mantle beneath the SCB had formed sequentially from inland to coastal since the late Mesozoic, and this may be related to lateral and vertical flow in the deep asthenosphere controlled by the break-off of subducted plates. [ABSTRACT FROM AUTHOR]

To explore the mechanical properties and fracture modes of basalt fiber-reinforced concrete, single-doped and hybrid-doped basalt fiber-reinforced concrete was prepared, and uniaxial failure tests under different basalt fiber-reinforced concrete contents were carried out. At the same time, the smooth kernel function in the traditional SPH method was improved, and the basalt fiber random generation algorithm was embedded in the SPH program to realize the simulation of the progressive failure of basalt fiber-reinforced concrete. The results show that under the circumstance with no basalt fiber, the specimen final failure mode is damage on the upper and lower surface, as well as the side edge, while the interior of the specimen center is basically intact, indicating that there is an obvious stress concentration phenomenon on the upper and lower surface when the specimen is compressed. Under the circumstance with basalt fiber, longitudinal cracks begin to appear inside the specimen. With the increase in the content, the crack location gradually develops from the edge to the middle, and the crack number gradually increases. This indicates that appropriately increasing the fiber content in concrete may improve the stress state of concrete, change the eccentric compression to axial compression, and indirectly increase the compressive strength of concrete. The numerical simulation results are consistent with the test results, verifying the rationality of the numerical simulation algorithm. For the concrete model without the basalt fiber, shear cracks are generated around the model. For the concrete model with basalt fiber, in addition to shear cracks, the tensile cracks generated at the basalt fiber inside the model eventually lead to the splitting failure of the model. The strength of concrete samples with basalt content of 0.1%, 0.2%, and 0.3% is increased by 1.69%, 5.10%, and 4.31%, respectively, compared to the concrete sample without basalt fiber. It can be seen that with the increase in the content of single-doped basalt fiber, the concrete strength is improved to a certain extent, but the improvement degree is not high; For hybrid-doped basalt fiber-reinforced concrete, the strength of concrete samples with basalt content of 0.1%, 0.2%, and 0.3% is increased by 14.51%, 15.02%, and 30.31%, respectively, compared to the concrete sample without basalt fiber. Therefore, compared with the single-doped basalt fiber process, hybrid doping is easier to improve the strength of concrete. [ABSTRACT FROM AUTHOR]

The Chang'E-6 (CE-6) mission successfully returned 1935.3 g of lunar soil samples from the Apollo basin within the South Pole–Aitken basin. One of its scientific objectives is to investigate the subsurface structure and regolith thickness at the landing site. Using remote sensing datasets, we estimated the regolith and basalt thicknesses at the landing site by employing the crater morphology method and crater excavation technique. A total of 53 concentric craters and 108 fresh craters with varying excavation depths were identified. Our results indicate that the regolith thickness at the CE-6 landing site ranges from 1.1 to 7.0 m, with an average thickness of 3.5 m. Beneath the regolith, the basalt layer consists of high-Ti basalt overlaying low-Ti basalt, with a total thickness of approximately 64 to 82 m, of which the high-Ti basalt layer accounts for about 22 to 30 m. Based on the local geological history, we proposed a stratigraphy at the CE-6 landing site. These findings provide valuable geological context for interpreting the Lunar Penetrating Radar data and analyzing the returned samples. [ABSTRACT FROM AUTHOR]

Determining subduction‐related processes is crucial for understanding lithological heterogeneity, as substantial quantities of slabs are recycled into the mantle. Molybdenum isotopes are valuable for distinguishing sources materials due to the significant isotope differences between the crust and the mantle. In this study, we systematically investigate Mo isotopes in a suite of well‐characterized continental basalts from Keluo and Halaha‐Chaoer, located in Northeast China. The δ98Mo values of Keluo range from −0.41 to −0.23‰, with an average of −0.34‰, while Halaha‐Chaoer samples ranged from −0.18 to −0.12‰, with an average of −0.15‰. The δ98Mo values of Keluo basalts are lighter than the mean value of fresh oceanic basalts (−0.21‰), whereas those of Halaha‐Chaoer basalts are similar to oceanic basalts. Combined with other geochemical indications (LOI, Ce/Pb, La/Yb and so on), the Mo isotopic variations cannot be attributed to chemical weathering, continental crust contamination or magmatic processes. Instead, the δ98Mo variations in this study are explained by the incorporation of different oceanic crustal materials into the magma sources. Correlations of δ98Mo with Ba/Th, Th/U, 143Nd/144Nd indicated that both sediment and altered oceanic crust have significantly influenced these variations. This study demonstrates the potential of Mo isotopes to distinguish different types of recycled oceanic crust materials. [ABSTRACT FROM AUTHOR]

New isotopic data are presented in this paper that make it possible to determine the stratigraphic position of the Talja Formation on the regional stratigraphic scale of the Early Precambrian. The U‒Th‒Pb age of 1926 ± 7 Ma obtained for the first time for metarhyodacites of the Talja Formation indicates that this formation is coeval to the Kaskama Formation, which, together with the similar isotope–geochemical composition of the type varieties of the Kaskama and Talja formations (komatiitic basalts, aluminous metabasalts, and metarhyodacites), significantly expands the understanding of the extent of the area composed of the Paleoproterozoic Kalevian Superhorizon within the Kola–Norwegian region of the Fennoscandian shield. [ABSTRACT FROM AUTHOR]

The Badia Epigraphic Survey (BES) Project was launched in 2015 by Ali Al‐Manaser and Michael C. A. Macdonald and, with two gaps, has been conducting annual surveys in the ḥarra of north‐eastern Jordan ever since. The 2023 survey, like that of 2018, set out to rediscover the cairns at the border between the ḥarra and the ḥamād at which, in the late 1950s, Professor Fred V. Winnett and Gerald Lankester Harding (WH) discovered over 4000 inscriptions. The purpose was to identify the WH cairns by the inscriptions on them, to give them exact locations using Global Positioning System and to photograph all the inscriptions, most of which WH had had to record in hand copies. In the process, numerous inscriptions at other cairns were also recorded, as well as large numbers of modern Arabic inscriptions carved in the 65 years since the WH expedition. This article describes some of the finds made, gives the exact locations of the WH cairns rediscovered and discusses some of the interesting ancient and modern inscriptions and drawings which were found. [ABSTRACT FROM AUTHOR]

This study assesses heavy metal (HM) concentrations and ecological risks in soils derived from granite (GrS), basalt (BtS), and amphibolite (AmS) rocks in southern Bundelkhand, central India. HM analysis reveals substantial variations, with Cr, Mn, Co, Ni, Zn, and Cd exhibiting higher concentrations in AmS, followed by BtS and GrS. Mn and Co content exceeds the Indian limit for soil (IS) and European Union (EU) guidelines for most samples. The geo-accumulation index shows high pollution levels of Cd in all soil types. Enrichment factor (EF) assessment reveals significant enrichment of Cd in GrS and BtS (mean 12.53, 6.91, respectively), and Cr, Ni, and Cd in AmS. The potential contamination index (Cp) and pollution load index (PLI) confirm Cd as the most significant contaminant in all soil types, with AmS exhibiting the highest pollution levels (29.31 and 650.68, respectively). The potential ecological risk (RI) assessment identifies Cd as the major contributor to ecological risk in all soil groups, with GrS and BtS displaying low to moderate risk, and AmS posing high to very high ecological risk. Our study highlights the influence of parent material on soil heavy metal concentrations, potentially leading to groundwater contamination and posing risks to human health. [ABSTRACT FROM AUTHOR]

Mid‐ocean ridge basalts reflect the mantle's composition and reveal processes from melting to eruption. The Mohns and Knipovich Ridges have ultraslow spreading rates, low magma budgets and erupted lavas indicating various mantle domains. Here, we use geochemistry and isotope systematics of in situ samples from two axial volcanic ridges (AVRs) to study mantle heterogeneity and melt production. By linking chemical variations to high‐resolution bathymetry and age data, we document systematic changes over time in the mantle source of the volcanic sequence. At Mohns Ridge AVR‐M10 (72.3°N), we observed significant variations in chemistry (e.g., (La/Sm)N from 0.7 to 2.9) and isotope systematics in basaltic samples from a small area (∼1 km2), suggesting the emplacement of multiple small‐volume lava flows. Pb isotope variations, for example, 206Pb/204Pb (17.91–18.76), are comparable with the observed range along the entire Mohns and Knipovich Ridges. Temporal constraints document that erupted basalts have changed from highly radiogenic Pb compositions to a more depleted signature within 30 ka. To explain the extreme variations in the erupted lavas at the Mohns Ridge, the mantle would need to be highly heterogeneous in composition with effective melt extraction and limited mixing prior to eruption. We use the highly heterogenous mantle underneath the Mohns Ridge to understand the melt extraction processes and mixing of melts and propose a two‐stage melting model: continuous generation of enriched melts from a deep and fertile source in the first stage, while depleted melts from a shallower and more refractory mantle occur sporadically and simultaneously with the intermittent ascent of diapirs. Key Points: Significant variations in chemistry within a small area suggest the emplacement of multiple small‐volume lava flowsTemporal constraints document that erupted basalts have changed from highly radiogenic Pb compositions to a depleted signature within 30 kaExtreme mantle heterogeneity is recorded in on‐axis lavas when melt extraction is efficient and homogenization in magma chambers is limited [ABSTRACT FROM AUTHOR]

Cement-stabilized crushed stone is widely used in the construction of high-grade highways because of its good durability and stability. However, cement-stabilized gravel is also easily affected by temperature and humidity, resulting in a reduction in the overall strength and durability of asphalt pavement. In response to this problem, in this study, we lay a single layer of a basalt fiber geogrids in a cement-stabilized gravel base of a test section of the Yan-Chong Expressway. The bonding and friction forces formed between the basalt fiber geogrids and the base as well as the mechanical bite force, play an anti-cracking role. We conducted a comparative experimental study on the mechanical properties of basalt fiber geogrids reinforced or not reinforced with cement-stabilized gravel specimens of different ages. The results showed that (1) the unconfined compressive strength of cement-stabilized gravel was slightly reduced; (2) the splitting strength was somewhat improved; (3) the compressive elastic modulus was slightly reduced; (4) the flexural and tensile strengths were significantly increased. An improvement in the crack resistance in semi-rigid base materials can improve the service life of high-grade asphalt pavements. [ABSTRACT FROM AUTHOR]

Crushed stone is one of the most exploited and important mineral raw material. Emphasis is given to determination of mineralogical and petrographic properties, of two genetically different rocks of silicate composition, commonly used as crushed stone for road constructions, as their physical properties depend on them. First is amphibolite from Vetovo, and second is basalt from Vratnik locality, both sourced from Croatia. Tests conducted according to European and Croatian norms evaluated the real and apparent density, open and total porosity, and water absorption of stones. The relationship between mineralogical and physical properties led to the following conclusions: the open porosity values of amphibolite samples are low, which is a consequence of the medium to high degree of metamorphism, (plagioclase and hornblenda), sosiritization, and undisturbed rock features. The total water saturation was achieved in a brief time, confirming this statement. The basalts have different porosity and water absorption values, which are consequences of differences their textural-structural properties (glassy, intersertal or intergranular groundmass), amount of amygdules, presence or absence of chlorite/volcanic glass. Furthermore, the percentage of plagioclase in the modal composition differs, and the plagioclase itself has been altered, and the amount of clay, sericite and calcite vary in two different varieties of basalt. Compared to amphibolites, basalts have notably higher water absorption values as well. Accordingly, the studied amphibolite has water absorption less than 0.5% and is suitable for use in a road construction application for wearing course in the asphalt pavement, and studied basalt is not.Article Highlights: Properties of amphibolite and basalt samples from Croatia were determined according to the European and Croatian norms. Mineralogical and petrographical properties significantly influencing the physical properties and they must be determined in detail. Amphibolite (Vetovo locality) is suitable as crushed stone for wearing course in the asphalt pavement in road construction, while basalt (Vratnik locality) is not. [ABSTRACT FROM AUTHOR]

The dynamics of phosphorus are intricately governed by geological and ecological processes. Examining phosphorus dynamics in volcanic islands can enhance our comprehension of its behavior within such unique geological systems. However, research on phosphorus dynamics in volcanic islands remains limited. We investigated the phosphorus content of volcaniclastic rocks and basalt soils from Weizhou Island, China, to understand the influencing factors on phosphorus dynamics. The results indicate that in the volcaniclastic profile, phosphorus concentrates at 20–40 cm (17 mg/kg), decreases at 40–60 cm (11.9 mg/kg), and increases at 80–200 cm up to 46.4 mg/kg proximate to the bedrock, for the basalt profile, phosphorus content increases from the surface (80.2 mg/kg) towards the bedrock (83.9 mg/kg). The differences in phosphorus distribution between volcaniclastic rocks and basalts reflect the influence of parent material, rock weathering degree, carbonate content, topographic elevation, sea level changes, and geological activities. A strong positive correlation (R = 0.96907) between total and available phosphorus has been observed, suggesting that total phosphorus content effectively predicts available phosphorus content. Volcaniclastic rocks in wharves and high-elevation areas show low total phosphorus, while forest land with dense vegetation and neutral to alkaline soil supports higher total phosphorus due to enhanced bioavailability for plant absorption and utilization. Overall, the basalt soil of the volcanic island Weizhou Island demonstrates superior long-term fertility compared to the volcaniclastic soil. Despite its low total phosphorus content, it mainly exists in a highly bioavailable form, facilitating plant absorption, which is crucial for enhancing agricultural yields and ecosystem restoration on volcanic islands. [ABSTRACT FROM AUTHOR]

The upper mantle low velocity zone is often attributed to partial melting at the lithosphere-asthenosphere boundary. This implies that basaltic melts may be stable along plausible geotherms due to the freezing point depression in the presence of water and other incompatible impurities. However, the freezing point depression (ΔT) as a function of water content in the near-solidus basaltic melt (cH2O) cannot be precisely determined from peridotite melting experiments because of difficulties in recovering homogeneous basaltic glasses at high pressures. We therefore used an alternative approach to reinvestigate and accurately constrain the ΔT–cH2O relationship for basaltic melts at the low water fugacities that are expected in the upper mantle. Internally heated pressure vessel (IHPV) experiments were performed at water-saturated conditions in the anorthite-diopside-H2O system at confining pressures of 0.02 to 0.2 GPa and temperatures between 940 and 1450 ℃. We determined the water-saturated solidus, and obtained ΔT by combining our data with reports of dry melting temperatures in the anorthite-diopside system. In another series of experiments, we measured water solubility in haplobasaltic melts and extrapolated cH2O to pressures and temperatures of the water-saturated solidus. By combining the results from these two series of experiments, we showed that the effect of water on ΔT was previously underestimated by at least 50 ℃. The new ΔT–cH2O relationship was then used to revise predictions of melt distribution in the upper mantle. Hydrous melt is almost certainly stable beneath extensive regions of the oceanic lithosphere, and may be present in younger and water-enriched zones of the subcontinental mantle. [ABSTRACT FROM AUTHOR]

Primary magmas form by partial melting in the mantle of a terrestrial planet and represent the starting material for building its crust. The compositions of primary magmas are critical for understanding the thermal history of planetary interiors, as they can be used to estimate mantle potential temperatures (TP) and track changes in the conditions of mantle partial melting over time. Here, we introduce PRIMARSMELT, a new member of the PRIMELT software family, calibrated to estimate the composition of Martian primary magmas and their formation conditions. We applied PRIMARSMELT to a comprehensive database of basaltic compositions from Mars. Our results are consistent with their petrology, requiring olivine addition to restore fractionated compositions to their primary parents and olivine subtraction from cumulate rocks. Individual primary magma solutions provide insights into the petrogenesis of specific Martian meteorites, with implications for the near‐primary nature of some primitive meteorites and the relationship between lithologies A and B in meteorite EETA 79001. Taken together, our results suggest nearly constant or potentially increasing mantle potential temperatures throughout the geological history of Mars. The average TP for young shergottite meteorites is ∼1,442 ± 40°C, similar to ambient mantle temperatures inferred from geophysical models. In contrast, older basaltic rocks record potential temperatures as low as ∼1,320 ± 48°C for igneous clasts in meteorites NWA 7034/7533. We suggest that, rather than plume‐related magmatism, shergottite meteorites record ambient mantle temperatures, with the thermal evolution trend possibly resulting from inefficient heat loss, as expected for a planet in stagnant‐lid mode. Plain Language Summary: Primary magmas, formed from the melting of a planet's mantle, are the materials from which the crusts of terrestrial planets are formed. Establishing their composition helps us understand the thermal state of a planet's interior and how it changes over time. We developed PRIMARSMELT, a software tool that estimates primary magmas on Mars using the measured chemical compositions of Martian meteorites and surface rocks. When applied to different Martian samples, PRIMARSMELT produces results that shed light on their origins and relationships. Notably, when combining our results for some suitable samples with their ages, we found that the internal temperature of Mars appears to have remained steady or may even be increasing with time. The primary magmas of young meteorites record temperatures around 1,442°C, while those of older rocks are around 1,320°C. These findings suggest that Mars may not cool efficiently, likely because of its stable outer shell, which does not allow heat to escape as it does on more geologically active planets like Earth, where plate tectonics permits efficient cooling. Key Points: We developed PRIMARSMELT, a new software tool for estimating the composition and conditions of formation of primary magmas on MarsPrimary magma solutions from PRIMARSMELT provide new insights into the formation conditions and petrogenetic history of some Martian rocksOur results from PRIMARSMELT may indicate steady or potentially increasing mantle temperature throughout the geological history of Mars [ABSTRACT FROM AUTHOR]

With growing environmental concerns due to the excessive use of natural river sand in construction, finding sustainable alternatives is crucial. This study explores the potential of basalt waste dust, a by‐product of basalt rock crushing, as a replacement for river sand in one‐part geopolymer mortar. The experimental program is segmented into three series: replacing river sand with basalt waste dust at 25%, 50%, 75%, and 100%; adjusting the activator‐to‐binder ratio as 0.12, 0.15, 0.18, and 0.21; and modifying the aggregate‐to‐binder ratios (1, 1.4, 1.8, and 2.2). Results are discussed using various test results such as fresh property, hardened property, and microstructural property to provide a detailed analysis of mixture properties. Findings in series 1 reveal that replacing 50% of river sand with basalt waste dust optimally enhances the fresh and hardened properties of geopolymer mortar. In series 2, the varying activator‐to‐binder ratio with optimum replacement from series 1, activator‐to‐binder ratio 0.15, was found to be optimal, improving hardened properties. Further opting for this ratio in series 3 and increasing the aggregate‐to‐binder ratio to 2.2 was found to positively impact both the hardened and microstructural properties of one‐part geopolymer mortar. This study demonstrated that basalt waste dust plays a crucial role in these improvements and emphasizes the necessity of optimizing mix proportions to achieve superior performance, establishing basalt waste dust as a viable and sustainable alternative to river sand. [ABSTRACT FROM AUTHOR]

The samples from lunar farside have great significance for the study of the Moon, and even the solar system. Chang'e-6 landed successfully on the southern mare of the Apollo basin and returned ~2 kg of samples from lunar farside. To provide a better understanding for the background of the returned samples, we conducted detailed crater size-frequency distribution (CSFD) measurements in the Chang'e-6 landing region, the southern mare of the Apollo basin. The southern mare is divided into the western mare (W region) and the eastern mare (E region), and then subdivided into five subunits (W1, W2, W3, W4, W5) and three units (E1, E2, E3), respectively, according to the elevation, TiO2, and FeO abundances. Within the W2 and W5 region, more detailed subunits were separated out. The results show that the southern mare surface was active during two epochs, the Imbrian period and the Eratosthenian period. The basalt eruption lasted for ~1.7 Ga, from 3.28 Ga of the eastern mare to 1.54 Ga of the western mare. The W region is younger than the E region, while the three units of the E region have an age of ~3.2 Ga. The ages of the western mare basalts range from 2.98 Ga to 1.54 Ga, lasting for 1.4 Ga. It is worth noting that the age of the basalt at the Chang'e-6 sampling site is ~1.68 Ga, indicating the samples returned may include components with this very young age. [ABSTRACT FROM AUTHOR]

The management of arsenic residue (AR) poses a significant environmental challenge globally. Conventional methods such as landfill, adsorption, and purification often fail to prevent arsenic migration, leading to uncertainties about the final disposition of AR and risks of secondary pollution. Vitrification offers a more stable approach for solidifying AR. This study explores the vitrification mechanism of AR using basalt and evaluates the performance of the resulting fibers. Our findings indicate that increasing the arsenic concentration decreases the high-temperature viscosity of basalt, making fiber drawing more energy-efficient. Incorporating a small amount of arsenic (approximately 0.4 mol%) significantly enhances the tensile strength of basalt fibers (BFs) by 10 %, attributed to reduced viscosity and improved fiber formation with fewer internal defects. Additionally, the flexural strength and stiffness modulus of asphalt mixtures are notably improved with the addition of AR-BF composites. We also examined the solidification and leaching mechanisms of arsenic in the basalt glass system. BFs containing up to 0.4 mol% As 2 O 3 exhibited arsenic leaching levels below the standard threshold (<67.7 μg/dm2) under strong acid/alkali immersion conditions. These results highlight the potential for in-situ curing and recycling of hazardous AR, particularly in the development of mechanically reinforced materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights This work investigates the addition of milled carbon fiber reinforcement and its effect on scratch resistance and mechanical durability for basalt fiber/epoxy composites, assessed under varied loading conditions with the aid of different indenter types according to a factorial design. Composites with MCF content from 0 to 10 wt% were prepared. Scratch behaviors under Vickers and Rockwell indenters were studied for loads of 5, 10, and 15 N. The addition of 10 wt% MCF has resulted in scratch hardness increase from 13.255 N/mm2 up to 47.952 N/mm2, depending on the type of indenter used. Precisely, in conditions of a 5 N load and when a Rockwell‐type indenter was used, a scratch hardness maximum of 47.952 N/mm2 was achieved, while for a Vickers‐type indenter under the same conditions, the maximum value of its equivalent was 23.327 N/mm2. Profilometric and SEM analyses evidence that matrix cracks and surface deformation have been reduced with higher MCF content, at least for the application of lower scratch test loads. The mechanical and surface performances of the basalt fiber composites were found to be considerably improved by the reinforcement with MCF. Scratch resistance for milled carbon fibers increases and peaks at 10 wt% reinforcement. The Rockwell indenter indicates a steady increase in hardness up to 47,952 N/mm2. Peak hardness of 10 wt% is observed under the Vickers indenter for the 5 N load. Higher milled carbon fiber content reduces matrix cracking and surface deformation. There is a clear correlation between scratch performance, milled carbon fiber content, and indenter type. [ABSTRACT FROM AUTHOR]

The intersection of the Foundation Plume with the Pacific-Antarctic Ridge is a key location in global geodynamics where a mantle plume is approached by and interacting with a fast-spreading mid-ocean ridge. Here, we discuss a comprehensive major and trace element and Sr-Nd-Pb isotope dataset of new and existing samples from the young Foundation Seamount Chain (<5 Ma) and adjacent section of the Pacific-Antarctic Ridge. We use the geochemistry of axial, off-axis and intraplate lavas to map the spatial extent of plume dispersal underneath the ridge as well as the internal zonation of the upwelling plume. We show that the unusual length, increased crustal thickness and occurrence of silicic rocks on the axis of the Foundation Segment are the direct result of plume being tapped by the axial melting zone. We demonstrate that the plume is not homogeneous but shows a HIMU-like (high time-integrated [sup 238]U/[sup 204]Pb) OIB (Ocean Island Basalt) component characterized by [sup 206]Pb/[sup 204]Pb of up to 20.5 in its center and a more EM1-like (Enriched Mantle one) OIB component characterized by low U/Pb and [sup 206]Pb/[sup 204]Pb but high Rb/Nb and [sup 87]Sr/[sup 86]Sr towards its edges. Plume entrainment leads to a high magma supply rate that fosters the formation of silicic rocks and triggers the lengthening of the segment over time. However, plume dispersal is not symmetric as the geochemical tracers for the OIB component are extending <100 km northwards but >300 km southwards. We relate this to the current plate tectonic framework in which the obliquity between the migrating ridge and the absolute plate motions induces a sub-axial asthenospheric flow that preferentially channels plume material southwards. [ABSTRACT FROM AUTHOR]

Translation abstract Durable and sustainable bridge caps made of non‐metallic reinforcement and recycled concreteDue to chloride‐induced corrosion, bridge caps made of steel‐reinforced concrete need to be replaced regularly or more often than planned. As part of a ZIM project funded by the Federal Ministry for Economic Affairs and Climate Action, bridge caps made of non‐metallic basalt fibre reinforcement and recycled concrete were developed to mitigate the weakness of corrosion and to better utilize the materials in terms of the material cycle. To achieve this, bend reinforcement elements made of chloride‐resistant basalt fibre reinforcement and concrete with high frost‐thaw resistance were developed, consisting of up to 100 % recycled aggregate. All sub‐developments were integrated into a holistic approach, and a prototype of a resource‐efficient and durable bridge cap was successfully produced and tested. [ABSTRACT FROM AUTHOR]

The availability of fiber‐reinforced polymers (FRP) as an alternative for conventional steel reinforcement in concrete construction is increasing. To widen the scope of application, for example, in the case of prestressing, and to improve the bond behavior at the bar ends, end anchorages need to be considered. Within this paper, a new short‐length anchor representing a combination between a bond and mechanical anchor is presented using a special inner geometry to increase the load‐bearing capacity due to the mechanical wedge effect, with a bonding length of only 50 mm. Besides giving a short overview of different anchorage systems, the paper focuses on experimental investigations that were performed with mechanical bond anchors with a variation of the inner geometry of the steel anchorage, different FRP bars, and different load transfer media. A numerical investigation completes the study by showing an approach to calculate the presented mechanical bond anchors. It was found that a small thickness of the bonding material is favorable, and a decrease of the bonding length is not necessarily disadvantageous. A tensile failure of the FRP bars was not achieved, although a full exploitation seems promising since a utilization of up to 83% of a basalt FRP bar was reached. [ABSTRACT FROM AUTHOR]

Water film thickness (WFT) is a primary factor influencing the flowability of cement mortar and gypsum slurry. However, conventional WFT calculation models have overlooked the impact of fiber surface properties on flowability. This study addresses this issue by introducing a parameter called the residual moisture distribution coefficient into the residual moisture distribution coefficient (RMDC) and the WFT calculation model. Thirty-six groups of basalt fiber-Phosphogypsum composite slurry with varied mix proportions were designed and assessed for their flowability and packing density. The RMDC and WFT were derived from fitting with the improved model. Finally, a basalt fiber-Phosphogypsum composite slurry flowability prediction model based on WFT was established, laying a foundation for the design and further application of fiber-gypsum composite flowability. [ABSTRACT FROM AUTHOR]

This study presents the trace element geochemistry of an 851-m thick basaltic succession from the central part of the southeastern Ethiopian plateau (Chole section) to assess the petrogenesis and temporal geochemical evolution of the Chole basalts. The composition of trace and major elements in the Chole section varied temporally, and three distinct magma types were identified; lower, middle, and upper basalts. The lower and middle basalts are highly enriched in incompatible trace elements with strong positive Nb and negative K anomalies in the primitive-mantle-normalized multi-elemental variation diagram. Both exhibit similar middle to heavy rare earth element fractionation patterns. However, the middle basalt shows distinctive negative U, Th, and positive Ba anomalies, with higher Ba/Th, Ba/Nb ratios, and more pronounced light-to-heavy rare earth element fractionation, suggesting varying degrees of mantle metasomatism and partial melting in the lithospheric mantle. The trace element signatures indicate that these basalts originated from the melting of garnet-bearing lithospheric mantle mixed with rising plume component. The upper basalt reveals two groups: the lower flows show moderate enrichment with a strong negative K anomaly, while the upper flows display highly enriched trace elements with crustal influence. Trace element signature in the uncontaminated upper basalt indicates partial melt contribution from the spinel-garnet transition zone of the depleted component, probably the melting of the sub-lithospheric mantle and hydrated lithospheric mantle or partial melting of the previously depleted part of the lithospheric mantle. [ABSTRACT FROM AUTHOR]

It remains uncertain whether a stagnant slab in the mantle transition zone can affect the asthenospheric mantle beyond its leading edge. To address this question, we investigated Cenozoic alkaline basalts from the Dariganga volcanic field (DVF) in southeastern Mongolia. The DVF is located west of North–South Gravity Lineament (NSGL) in Eastern China, which is spatially coincident with the seismically detected stagnant Pacific slab front. Basalts from the DVF consist of nephelinite, basanite and alkali olivine basalt. These rocks have relatively high Nb/U (average = 58) and Nb/La (>1) ratios and radiogenic Nd–Hf isotopic compositions. They also have high Ca/Al (0.60–1.13), Zn/FeT (13.5–16.5), and FeO/MnO (77–112) ratios as well as low δ26Mg (−0.42‰ to −0.26‰) values, reflecting an asthenospheric mantle source modified by carbonated eclogite‐derived melts. Pb–Nd–Hf isotope characteristics indicate that the carbonated eclogite‐derived melts likely originated from the stagnant Pacific slab. Although Cenozoic basalts from both the east of the NSGL (ENSGL) and DVF domains exhibit light δ26Mg values, basalts from the ENSGL nevertheless have lower δ26Mg values than those in the DVF domain. This suggests a gradual westward decline in the amount of carbonated melts/fluids derived from the stagnant Pacific slab. This variation trend, combined with a more fertile and oxidized asthenospheric mantle toward the ENSGL, indicates that the stagnant slab has affected the mantle and created a compositional aureole beyond its leading edge, which substantially contributed to the formation of the alkaline basalts in the DVF. Plain Language Summary: Subducted slabs can exert a profound influence on overlying mantle domains. However, it remains uncertain whether material from a stagnant subducted slab in the mantle transition zone can influence the mantle domain beyond its leading edge and contribute to the formation of alkaline basalts. This article presents a study on Cenozoic alkaline basalts in SE Mongolia, which lie west of the North–South Gravity Lineament, beyond the leading edge of the stagnant Pacific slab. The Cenozoic alkaline basalts in SE Mongolia are characterized by relatively high Ca/Al, Nb/U and Nb/La ratios. They also show depletion in Pb–Zr–Hf and have radiogenic Nd–Hf and relatively light Mg isotopic compositions, which is consistent with their origination from an asthenospheric mantle source modified by carbonated eclogite‐derived melts. Radiogenic isotopic compositions suggest that the carbonated melts were likely derived from the stagnant Pacific slab. Furthermore, there is a westward decline in signals of carbonated melts/fluids derived from the stagnant Pacific slab. These findings suggest that the stagnant Pacific slab has influenced the mantle domain beyond its front edge, leading to a differential modification of the asthenospheric mantle and the formation of intraplate alkaline basalts in the Dariganga volcanic field. Key Points: The Cenozoic alkaline basalts in Dariganga were sourced from asthenospheric mantle modified by carbonated eclogite‐derived meltsThe carbonated eclogite‐derived melts were derived from the subducted Pacific slab that stagnated in the mantle transitional zoneThe influence of the carbonated melts/fluids waned westward, resulting in a compositional aureole across the North–South Gravity Lineament [ABSTRACT FROM AUTHOR]

The Tarim Craton is an ancient Precambrian continental block, and detailed knowledge of its thermo‐tectonic history is crucial for understanding the early history of continental evolution. Abundant layered mafic rocks, which have commonly been regarded as basalts, occur within the Ediacaran Sugetbrak Formation (Fm.) in the Aksu region of the northwestern Tarim Craton. Clear intrusive features have now been discovered, including mafic rocks truncating Ediacaran sedimentary layers, exhibiting an intrusion‐baked margin where they interact with both the overlying and bottom wall rocks, and displaying a fine‐grained transition zone from their interior to their margins. The new findings demonstrate that these mafic rocks within the Aksu Ediacaran strata were not erupted basalts but instead are intrusive diabase dykes. Therefore, these mafic rocks cannot be used to constrain the timing of the Sugetbrak Fm. in the Aksu area, nor as marker layers for regional stratigraphic correlation. Furthermore, the Ediacaran thermo‐tectonic evolution in this region, deduced from the assumption that the mafic rocks are lavas, needs to be revised. [ABSTRACT FROM AUTHOR]

In this study, we investigated Early Paleozoic magmatic rocks of the Manlai Formation exposed along the eastern margin of the Lancang terrane to better understand the tectonic history of the Proto-Tethys. We present petrological, geochemical and whole-rock Sr-Nd and zircon Hf isotopic data for basalts and gabbros sampled from the Qianmai mélange. Zircon grains from six basaltic and gabbroic samples yielded U-Pb ages of 495–482 Ma. These rocks are characterized by tholeiitic and Nb-enriched compositions, with Nb/La ratios in the range of 0.38–1.38, similar to the typical Nb-enriched basalts. All the mafic rocks show slightly negative to positive εNd(t) (−1.67 to + 4.32) and zircon εHf(t) values (−7.3 to +3.8). Elemental and isotopic data suggest that the Qianmai Nb-enriched mafic rocks were mainly derived from the mixing of an OIB-like source with a subduction-modified mantle wedge source. Together with magmatic and sedimentary records of similar ages in the Lancang terrane and the Baoshan Block, our results reveal Early Paleozoic magmatic and sedimentary sequences along an active margin of the Proto-Tethys. Taking into account the recently identified Early Paleozoic ophiolitic mélange in the Yunxian-Menghai belt, we consider the Qianmai magmatic rocks to represent the products of early-stage subduction-related magmatism within a primitive island arc or fore-arc setting associated with the southward subduction of the Proto-Tethys. We infer that prolonged south-dipping subduction on the northern margin of Gondwana persisted from the Cambrian to the Late Ordovician. [ABSTRACT FROM AUTHOR]

Currently, sustainability plays a central role in the response to global challenges, strongly influencing decisions in various sectors. From this perspective, global efforts to explore inventive and eco-friendly solutions to address the demands of industrialization and large-scale production are being made. Bio-based composites needed for lightweight applications benefit from the integration of natural fibers, due to their lower specific weight compared to synthetic fibers, contributing to the overall reduction in the weight of such structures without compromising the mechanical performance. Nevertheless, challenges arise when using natural fibers in composite laminates and hybridization seems to be a solution. However, there is still a lack of knowledge in the literature regarding the strategies and possibilities for reducing laminate thickness, without sacrificing the mechanical performance. This work aims to fill this knowledge gap by investigating the possibility of reducing the laminate thickness in hybrid flax/basalt composites made of plies, organized in the same stacking sequence, through only varying their number. Tensile, Charpy, flexural, and drop-weight tests were carried out for the mechanical characterization of the composites. The results obtained confirm the feasibility of achieving thinner hybrid composites, thus contributing to sustainability, while still having acceptable mechanical properties for structural applications. [ABSTRACT FROM AUTHOR]

Additive manufacturing processes allow for precise and efficient production, but it is estimated that one-third of the materials used results in waste. Further improvement in a sustainable perspective could come from the ability to manage these scraps and from the exploration of different routes for recovery and reuse. The Selective Laser Sintering process is particularly sensitive to this issue due to the waste ratio which can reach a very high quantity of not-sintered virgin powders. In this research study, recovered PA12 powders, preliminarily characterized through thermal and mechanical analysis, were mixed with 15% basalt powder to improve their aspect and thermomechanical resistance. The influence of basalt powder (BP) on mechanical properties as well as on the thermal stability of polyamide12 (PA12) powder composites was investigated. A study conducted on mechanical properties showed that polymeric composites' stiffness and hardness were influenced by adding filler, thus improving mechanical parameters. On the other hand, the application of thermogravimetric analysis allowed us to determine the composite's thermal stability. The objective is to obtain a recovered fully biobased material that could be used to substitute the petroleum-derived polymeric ones currently employed in the production of interiors and shells in the automotive sector. [ABSTRACT FROM AUTHOR]

The length of basalt fibers affects the performance of asphalt mixtures. To explore the influence of different lengths of basalt fibers on the performance of asphalt mixtures, this study selected basalt fibers with lengths of 6 mm, 9 mm, and 12 mm to design gradations that were incorporated into asphalt mixtures to prepare specimens. High-temperature rutting tests, immersion Marshall tests, freeze-thaw splitting tests, and low-temperature splitting tests were conducted, resulting in 11 test mix designs and 12 test indicators. Then, a multi-objective grey target decision method was used to optimize the optimal combination ratio of basalt fiber lengths. The results indicate that compared to asphalt mixtures with single-length basalt fibers, incorporating well-combined basalt fibers significantly enhances the high-temperature, low-temperature, and water stability performance of asphalt mixtures. According to the grey target decision method, this study determined that a basalt fiber combination ratio of 3:4:3 for lengths of 6 mm, 9 mm, and 12 mm provides the best overall performance of asphalt mixtures. Additionally, when designing asphalt mixtures with graded basalt fibers, the inclusion of 9 mm fibers should be the primary control point. These research findings provide important guidance for the enhanced application of basalt fibers in road engineering. [ABSTRACT FROM AUTHOR]

Based on an analysis of the literature on fiber‐reinforced concrete (FRC), especially the development and formation of various types of FRC combined with reactive powder concrete (RPC) in recent years, this paper systematically expounds the research progress, particularly the mechanical properties, of steel fiber RPC, basalt fiber RPC and hybrid fiber RPC. This paper concludes the improvement in the mechanical properties of RPC under common curing methods, elaborates on the influence of steel fiber on the compressive, tensile, and flexural strength of RPC, and outlines the principle of fiber enhancing the mechanical properties of RPC. Additionally, it discusses the research progress in basalt FRC, and further examines the impact of basalt fiber on the mechanical properties of RPC. Referring to the research on single fiber reinforced RPC, the mechanical properties of hybrid fiber RPC are analyzed and summarized; based on the characteristics of steel fiber and basalt fiber, research on steel‐basalt hybrid fiber RPC is proposed. [ABSTRACT FROM AUTHOR]

To investigate the flexural behavior of hybrid reinforced concrete (Hybrid‐RC) beams with Basalt fiber‐reinforced polymer (BFRP) bars and steel bars, this paper designed 14 Hybrid‐RC beams and studied the effect of different reinforcement forms on the flexural behavior of Hybrid‐RC beams. The research results indicated that when ρ≈2.28%$$ \rho \approx 2.28\% $$, an increase in Af/As$$ {A}_{\mathrm{f}}/{A}_{\mathrm{s}} $$ leads to a decrease in the cracking moment, ultimate moment, and ductility of Hybrid‐RC beams, the maximum crack width and deflection will increase. When ρ≈0.86%$$ \rho \approx 0.86\% $$, an increase in Af/As$$ {A}_{\mathrm{f}}/{A}_{\mathrm{s}} $$ will lead to a decrease in the cracking moment, deflection, and ductility of the Hybrid‐RC beams, while the maximum crack width and ultimate moment will increase. In addition, when ρ≤1.87%$$ \rho \le 1.87\% $$, the area of BFRP bars (the area of steel bars remains unchanged) should be changed to improve the flexural behavior of the Hybrid‐RC beams; When ρ>1.87%$$ \rho >1.87\% $$, the Hybrid‐RC beams should change the area of steel bars (the area of BFRP bars remains unchanged) to improve the flexural behavior of the beams. In addition, the ductility index prediction equation for Hybrid (BFRP and steel)‐RC beams was fitted based on the results of the theoretical model research. [ABSTRACT FROM AUTHOR]