Basaltic Layer Research Articles

The Lunar Regolith Thickness and Stratigraphy of the Chang’E-6 Landing Site

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.

Diverse magmatism along the northern margin of Tarim during the Ediacaran: Transition from Rodinian dispersing to Gondwana assemblage

The Ediacaran igneous rocks and sedimentary sequences play a key role for our understanding the transition from dispersing of the Rodinian continents to the assemblage of the Gondwana. On the other hand, some continental massifs at the marginal area of the Rodinia and Gondwana could preserve solid evidences for deciphering the geodynamic background from the break-up of Rodinia to the assemblage of Gondwana. In this contribution, we report field observations, petrography, ages and systematic geochemistry of the diverse Ediacaran igneous activities in the northern margin of the Tarim Block, which was favored as a marginal continental massif in the Rodinia configuration by most geologists. The Ediacaran igneous rocks along the northern margin of Tarim include the Baicheng and Yangxia granites, Tiemenguan syenite, Kurle mafic dykes and the basalt layers in the Zamoketi Formation (northeastern Tarim) and the Sugetbrak Formation (northwestern Tarim). Precise zircon UPb dating revealed that these distinct rocks were broadly coeval with crystallization/eruption ages of 630–600 Ma. Bulk-rock elemental and SrNd isotope compositions as well as zircon LuHf isotope compositions demonstrate that the Baicheng and Yangxia granites were derived from Neoarchean mafic lower crust and underwent intensive fractionation before their emplacements. The Tiemenguan syenites have potassic andesitic compositions, in combination with their pronounced enriched NdHf isotopes and extremely high Zr saturation temperatures (∼900 °C), we argue that their possible shoshonitic primary magmas were derived from previously metasomatized subcontinental lithospheric mantle source (amphibole-bearing) and then, coupling with assimilation and fractional crystallization (AFC) effects in magma chamber and/or en route to the emplacement space. This can account for their intriguing geochemical features. The ca. 615 Ma Zamoketi and Sugetbrak basalts and the slightly younger porphyrite dykes (ca. 580 Ma) cutting the Zamoketi basalt layer, show typical OIB-like geochemical signatures, they were most likely derived from a depleted asthenospheric mantle source with variable fractionation of olivine and pyroxene and negligible crustal contamination before eruption. On the whole, the geochemistry of the diverse Ediacaran igneous rocks unambiguously demonstrates that they were genetically related to an extensional environment. In combination with the significant passive continental features of the Ediacaran-Cambrian sedimentary sequences, we consider that these Ediacaran igneous rocks were the latest phase of igneous activity related to the dispersing of the Tarim at the margin of the Rodinia supercontinent.The dispersing of the Rodinian supra-continent was diachronic with the assemblage of the Gondwana. Late Tonian to Ediacaran dispersing of the Tarim from northern margin of Australia induced the opening of the Proto-Tethys Ocean. Then the initiation of the southward subduction of the Proto-Tethys Ocean at ca. 530 Ma (Fortunian) led to the Tarim assemblage to Gondwana at ca. 440 Ma.

Crustal-mantle layering deposits in the Von Kármán crater, South Pole-Aitken basin

Comprehending the properties of the Moon's crust and mantle materials is essential for decoding its interior. Whether the South Pole-Aitken (SPA) basin potentially excavated the upper mantle materials remains mysterious. The Chang'E Four Lunar Penetrating Radar (LPR) has provided an unprecedented opportunity to investigate the SPA basin in the Von Kármán (VK) crater. Utilizing a data-driven generative deep learning inversion algorithm, the subsurface physical properties along the Yutu-2 path were determined. 4 distinct deposit zones were discovered beneath the surface. All zones feature an upper low-permittivity (paleo-)regolith layer overlaying on a lower high-permittivity layer of rockier ejecta or basal basalt. Zone 1, an ejecta layer from the Finsen crater within the SPA Compositional Anomaly, has a bulk density (2.81±0.22g/cm3) denser than that of highland crust represented by materials originating from VKL and VKL' craters in the Mg-Pyroxene Annulus, which are present in Zones 2 and 3. This suggests the possible presence of mantle materials in Zone 1, providing the first diagnostic evidence that the SPA impact may have penetrated the upper lunar mantle.

Crustal origin for olivine in the lunar Shioli crater ejecta boulders: Insights from the geological setting of Theophilus crater and Nectaris basin

On the Moon, impact craters and basins expose a wide range of crustal and mantle rocks that provide excellent opportunity for sampling them, understanding their origins and reconstructing spatial and temporal evolution of lunar interior. The previous studies detected olivine-bearing mantle rocks in and around large impact craters and basins. The Japanese SLIM mission landed on the ejecta of a ∼ 280-m-diameter Shioli crater that was emplaced on the ejecta blanket of ∼ 103-km-diameter Theophilus crater, for characterizing potential mantle-derived olivine in the Shioli crater ejecta boulders. To test this hypothesis, we studied the geological setting of Shioli crater, host Theophilus crater and Nectaris multi-ring basin using the orbiter data from Chandrayaan-1 and 2, Lunar Reconnaissance Orbiter, and Kaguya missions and the earth-based Arecibo radar observation. The asymmetrically distributed secondary craters and impact melt ponds around Theophilus crater suggests that a northeast-directed oblique impact produced this crater. Composition of Theophilus crater and surrounding region indicates that the crater excavated a heterogeneous target composed of a thin layer of high-Al olivine basalt (Mare Nectaris) underlain by anorthositic highland rocks possibly intruded by Mg-suite plutons; layers of Cyrillus crater ejecta blanket and Nectaris basin materials (both ejecta and impact melt sheets) were also present beneath the mare basalt flows. Hence, the Theophilus ejecta blanket is a mixture of all these materials. Our dating of Theophilus crater suggests that it is a ∼ 2 Ga Eratosthenian crater. Shioli is a fresh simple crater that was formed at ∼ 1 Ma on the uprange ejecta blanket of Theophilus, where the Arecibo radar data indicated the presence of abundant buried Theophilus ejecta boulders. An ESE-directed hypervelocity oblique impact event produced the elongated Shioli crater and its asymmetrically distributed bright ejecta. Shioli is a primary impact crater indicating the role of impact spallation processes associated with this hyper-velocity impact in producing thousands of ejecta (or spall) boulders around Shioli crater, displaying their asymmetric dispersal pattern and spatial variation of boulder sizes and shapes. The larger and elongated boulders are concentrated near the crater rim, while their size and axial ratio gradually decreases outward from the crater rim. The SLIM mission landed on a thin downrange ejecta of Shioli crater, where fewer large-size boulders are present. Our compositional study suggests that the Shioli ejecta boulders are composed of olivine basalt (Mare Nectaris) mixed with highland anorthositic fragments, including the reworked Cyrillus ejecta and Nectaris basin materials. The Shioli ejecta boulders were produced by complex impact fragmentation of already existing, buried Theophilus ejecta boulders. The regional crustal structure of Nectaris basin and its petrological composition suggest that both Nectaris basin and Theophilus crater did not excavate the lunar mantle. Therefore, the Shioli ejecta boulders are of crustal origin, including the olivine minerals present in them. Our results have important implications for the origin of olivine in the Shioli crater boulders being investigated by the SLIM mission.

On the Crustal Sources of Magnetic Anomalies in the Middle Urals

The 800×500 sq km area of the the Middle Urals, Russia, lying between 56 to 60° northern latitude and 54 to 66° eastern longitude, was studied in terms of the deep crustal structure. The study was based on three-dimensional modeling of the sources of magnetic anomalies in three layers of the Earth’s crust. The studied area covers the folded region of the Urals and adjacent structures of the East European Platform and the West Siberian Plate. The sources modeled in the near-surface layer down to a depth of 5 km make it possible to clarify the position of magnetized massifs, mainly consisting of mafic-ultrabasic rocks, and to trace their connection with mafic-ultrabasic belts in the granite layer and root blocks in the lower basaltic layer of the Earth’s crust. When the sources in the upper crustal layer are compared with those in the lower crustal layer, it is apparent that many belts on the platform have deep-seated roots and are located above the basalt layer protrusions, while most of the massifs in the Urals do not have deep-seated roots. The springs located under the western slope of the Urals allow reliably determining the depth to the basement of the ancient platform and the location of the eastern border of the East European Platform in the lower layer of the Earth’s crust. There were found extended zones of subsidence of the roof of the lower magnetized layer, which probably mark the boundaries of various terrains forming the paleo-island arc sector of the Ural fold system. The most extensive subsidence of the roof of the lower layer occurs to the west of the Tyumen-Chudinovsky fault and is perhaps the eastern deep-seated dividing line between the Ural fold system and the West Siberian Plate.

Глибинні геологічні моделі району надглибокої cвердловини Saatly DW-1 на основі комплексу геофізичних даних

The purpose of the article is to study the reasons for the failure to achieve the scientific and geological goals set for the ultra-deep well DW-1, drilled in the Saatli region of Azerbaijan. The analysis will focus on the existing deep models built for this region, which are deemed insufficient in reflecting the truth. The paper highlights the importance of adopting a new approach to the recently created deep model and its potential benefits to the scientific community.Methodology. The technique includes a detailed comprehensive analysis of the gravitational and magnetic fields in this region, the use of local magnetic anomalies to build a model of the deep geological structure utilizing data from deep seismic sounding (DSS) and the correlation method of refracted waves (CMRW). Results. The spatial position of effusive formations in the geological section was determined using the local anomaly of the geomagnetic field in the Saatly region. At the same time, the geometric dimensions of the volcanic body were chosen in such a way that the magnetic field created by it corresponded to the observed local magnetic field. Thus, a model of the geological section up to a depth of 15 km was developed, with the display of the spatial position of the volcanic formation. In this model, unlike the previous one, the spatial position of the volcanic formation in the vertical geological section is completely different. In the newly constructed model, it turns out that there is a separate volcanic formation in the area of the Saatly DW-1. And in the previous models, it was shown that the magma came here from the Muradhanly zone, located at a distance of 25-30 km. The boundaries of the crystalline foundation and the basalt layer in the area of the DW-1 in the zone of the volcanic body are not traced. The root of the volcano narrows and goes deep into the earth. At a depth of about 15 km, the magma-producing channel has a width of 1 km. Based on the established model, it was determined that the ultra-deep well DW-1 is located on the magma-producing channel of the volcano that existed here. From the analysis of the obtained model data, it turns out that the extension of the Saatly DW-1 to depth will not allow opening the consolidated crust (crystalline foundation) and basalt layer. Because, although these layers are closer to the earth's surface in the area of the DW-1, the active volcano here has destroyed these boundaries. Orginality. Seismic survey materials were used to study the deep structures of the region, gravimagnetic data on profiles with an observation step of 250 m, and a technique was applied to construct the spatial positions of effusive formations in the geological section. Scientific novelty. It has been established that the geomagnetic field of this region is formed from three main effects - the effect of the sedimentary complex, the effect of the thickness between the basement and Curie surfaces, and the effect of local manifestations of magmatism. The sum of the first two effects quite accurately corresponds to the regional background of the observed geomagnetic field. Local positive anomalies isolated from the observed field are associated with local heterogeneities - in this region with volcanogenic formations in the sedimentary complex. Practical significance. A new geological-geophysical model was created by determining the spatial position of effusive formations in the geological section near the Saatly DW-1 well using the local anomaly of the geomagnetic field. This model has real possibilities in the direction of installation of ultra-deep wells for the study of deep layers of the earth's crust.

Advanced hybrid composites: A comparative study of glass and basalt fiber reinforcements in erosive environments

AbstractThis study looks at how erosive wear affects hybrid composites made by vacuum infusing glass and basalt fibers into an epoxy matrix. The study uses garnet abrasives and a design experiment method to test how resistant these hybrid composites are to erosion at 30°, 60°, and 90° angles of impact. The analysis included three‐dimensional profilometry and scanning electron microscopy. Results show that glass layers enhance erosion resistance, whereas basalt layers increase wear. Key quantitative findings include erosion rates and mass loss, highlighting impingement angle and erosion time as critical factors. At a 30° angle, basalt exhibited more severe wear (erosion rate: 0.8090 mg/g for 20 s) compared to glass (erosion rate: 0.5683 mg/g). Conversely, at 90°, the erosion rate for basalt decreased to 0.3643 mg/g, indicating a decreased sensitivity to this steeper angle. According to the ANOVA, impingement angle and erosion time account for 30.08% and 50.25% of the erosion rate variance, respectively. These findings advance our understanding of material behavior in hybrid composites and emphasize the strategic selection and layering of materials for enhanced durability. This research contributes to developing more sustainable composites, demonstrating natural fibers' potential to improve mechanical properties and erosion resistance.Highlights Glass layers enhance durability against erosive forces in hybrid composites. Basalt layers accelerate erosion rates, showing a need for strategic layering. Glass fiber reinforcement significantly improves wear performance. Hybrid constructions with glass a top basalt balance flexibility and durability. Emphasizes eco‐friendly advantages of natural materials in composites.

Joint Inversion of Regional Waveform, First-Motion Polarity, and Synthetic Aperture Radar Surface Displacement for the Fourth and Sixth North Korean Declared Nuclear Explosions

ABSTRACT This study analyzed the Democratic People’s Republic of Korea’s (DPRK) fourth (DPRK4, 6 January 2016 Mw 4.49) and sixth (DPRK6, 7 September 2017 Mw 5.2) declared nuclear tests, employing a joint seismic and Interferometric Synthetic Aperture Radar (InSAR) inversion to improve understanding of these events and enhance moment tensor (MT) inversion capabilities. The recent efforts have focused on employing seismic waveform and InSAR geodetic deformation data separately to analyze these and the previous nuclear tests (e.g., Chiang et al., 2018; Myers et al., 2018; Wang et al., 2018). Building upon our previous work (Chi-Durán et al., 2021), we performed a joint regional waveform, first-motion (FM) polarity, and surface displacement inversion, which demonstrated improved source-type discrimination, a revised MT solution with reduced scalar moment uncertainty, and an independently constrained location. In this article, we build on the previous results for DPRK6 by including an analysis using a four-layered velocity model with free-surface topography to compute the near-source static deformation Green’s functions. The model consists of a 50 m basalt layer (VP=2.07 km/s, VS=1.2 km/s), a 250 m stratified volcanic deposit layer (VP=1.73 km/s, VS=1.0 km/s), a 700 m weathered granodiorite layer (VP=2.5 km/s, VS=1.3 km/s), and a granodiorite half-space (VP=5.35 km/s, VS=3.09 km/s). The half-space shares the velocity of the regional MDJ2 velocity model (Ford et al., 2010), which has proven effective for waveform inversion in the region. This model considers the range of reported values for various lithologies and weathering effects. Our findings show that using the layered velocity model enhances the recovery of source location and depth for both the explosions by improving fits and reducing uncertainties. The joint inversion also improves source-type discrimination and better constrains the scalar seismic moment necessary for downstream yield estimation.

Unveiling Subsurface Characteristics of Cliff Land in Sibang, Bali Through Geoelectric Investigation

The unique geological formations and environmental dynamics of cliffs underscore the significance of comprehending soil composition and structural integrity for diverse applications, such as infrastructure development and environmental conservation. Geoelectrical needs to be done because the underground geological conditions of the cliff must be researched and assessed first before construction is carried out so that construction failure does not occur. This research aims to reveal the subsurface characteristics of cliff soil in Sibang, Bali through geoelectrical investigation. This research was conducted by evaluating the soil condition in the field using the geoelectric resistivity method to the ability of a material to inhibit the flow of electric current and geological regional theories. At points BL-01 and BL-04, there is a significant potential risk of landslides due to the thick layer of breccia, especially during high rainfall or additional loads in the area. Point BL-02 also has a potential risk of landslides due to the thick layer of basalt and wet sand. Meanwhile, points BL-03 and BL-05 are more ideal locations for construction because they consist of relatively stable hard rock. Point BL-06 outside the development zone has layers of gravel, weathered tuffa and andesite which could be considered for future development. Thus, a deep understanding of the geological characteristics of each point is important to manage risks and ensure the safety and sustainability of construction projects in that area.

Crash-worthiness analysis of hollow hybrid structural tube by aluminum with basalt-bamboo hybrid fiber laminates by roll wrapping method

Hollow hybrid structural tubes were evaluated using commercial-grade Diamond Micro Expanded Mesh (DMEM) thin mesh of aluminum (Al) as structural reinforcement. Axial, transverse (flexural), and radial compression tests were performed on four different layered hybrid structures using bamboo (Bm) and basalt (B). With a maximum force of 34.7 kN, compressive ultimate strength of 238 MPa, and strain of 12.6%, AlBmB (with layers labeled from inside to outside) was the best performer in the axial compression test. AlBmB’s adaptability was demonstrated by the flexural test, showing a maximum bending force of 4.7 kN, a flexural strength of 97.7 MPa, and a decreased deflection of 13.2 mm. Radial compression test results underscored the superior energy absorption characteristics of AlBmB. The varying material interfaces in the hybrid tubes yielded distinctive performances. AlBmB, incorporating bamboo and basalt layers, stood out with superior energy absorption and crush force characteristics, indicating enhanced crashworthiness. The other hybrids AlBm, AlB, and BmB also exhibited commendable performances, emphasizing the adaptability of different material combinations. The meticulous selection of DMEM and innovative roll wrapping method for fabrication reliably influenced the tubes’ mechanical properties. The study contributes to advancing the design of lightweight, durable, and high-strength components.

Flexural and impact performance of Kevlar/basalt fabric interlayer hybrid curved composites

FRP composite has become one of the most preferred materials in lightweight applications. Design freedom is a key benefit which is reflected in the choice of fibres, stacking sequence and others. Hybridisation of hard inorganic fibre and organic ductile fibres can lead to synergetic effects. In this paper, an interlayer hybrid curved laminated composite reinforced with woven Kevlar and basalt fabrics and manufactured by a hand lay-up process with epoxy resin was prepared. Experimental investigation on the flexural and impact properties of composite laminates has been performed. The results of the investigation showed that the placement of Kevlar fibres on the impact side can increase the impact and flexural strengths, sample H3 (K3B2K3B2) has the highest impact strength and absorbed energy among seven hybrid laminates, valued at 92.89 KJ/m2 and 2.48 KJ. Compared with H5(B4K6) improved 41.6% and 40.9%, respectively. However, H5 has the highest flexural strength, reaching 231.7 MPa. In addition, the use of basalt fabric on the impact reverse side or multi-layer hybrid structuring further improves the impact properties of the materials. A sandwich-structure composite with basalt layers in the middle and Kevlar layers on both sides shows further improvement in the flexural properties.

The mobility of copper, zinc, molybdenum, and tungsten in subduction zone fluids

Porphyry-type ore deposits are closely associated with subduction zones, but the ultimate source of the metals in these deposits is still uncertain. To test whether aqueous fluids from the subducted slab may contribute to the metal enrichment, we investigated the partitioning of Cu, Zn, Mo, and W between saline aqueous fluids and the subducted basaltic crust at 2.5–3.0 GPa and 650–670 °C by experiments in piston cylinder presses. The bulk fluid/solid partition coefficients (Dfluid/solid) of Cu and Zn increase significantly with fluid salinity. For Cu, Dfluid/solid is less than 1 in a salt-free aqueous fluid, but at a salinity of 10 wt% NaCl, Dfluid/solid approaches 10. On the other hand, the Dfluid/solid of Zn is still below 0.4 even at the same salinity. Dfluid/solid of Mo is always relatively high (>4), with only a very slight enhancement by salinity at 2.5 GPa. The fluid/solid partition coefficient of W is close to 1 for a chloride-free fluid, but slightly decrease with increasing salinity. Overall, these experimental data show that saline aqueous fluids released from the basaltic layer of the subducted oceanic slab can effectively transport Cu and Mo and therefore enrich these two metals in the mantle wedge. This enrichment does not contradict the observation that Cu concentrations in primitive arc magmas and MORB are similar, since these concentrations may be controlled by a buffering sulfide phase. The enrichment of copper in the source then does not necessarily increase Cu concentrations in the melt, but it ensures that the copper-bearing sulfide phase is not exhausted during repeated melting events. For molybdenum, our data suggest that aqueous fluids from the slab are the major source of Mo in arc magmas. Due to the high pre-enrichment of Mo in some sediments, there may be a direct link between the types of subducted sediment and the location of porphyry Mo deposits. On the other hand, the contribution of slab fluids to the Zn budget of these magmas is likely negligible. The W partitioning data are consistent with isotopic evidence for the mobility of W in subduction fluids. Moreover, the behavior of Mo and W is strongly affected by the abundance of rutile in the solid residue. In a rutile-free lithology, not only Mo, but also W would strongly partition into the fluid. As some sediments may be highly enriched in W relative to the average mantle, fluids from such sediments may also produce a significant W enrichment in the mantle wedge, provided that the sedimentary residue is free of rutile.

Evidence of shallow basaltic lava layers in Von Kármán crater from Yutu-2 Lunar Penetrating Radar

Yutu-2 – the rover from the Chang’E-4 mission – is the longest operational Lunar rover, and the first rover to land on the far side of the Moon. It is the second planetary rover to be equipped with ground-penetrating radar (GPR), one of the few in-situ geophysical techniques used in planetary exploration. Since landing in 2019, Yutu-2 has travelled more than 1 kilometre in the Von Kármán (VK) crater, and has been able to investigate the dielectric properties of the shallow Lunar ejecta using its on-board high frequency GPR channels. In this paper, we use advanced signal processing and frequency attributes to infer a detailed dielectric structure of the first ≈30 metres of the subsurface, providing valuable information on the ilmenite content of the landing site. Both the dielectric properties and the ilmenite content suggest a shallow sequence of Imbrian basaltic layers overlaying a low-ilmenite ejecta blanket.

Basin filling and magmatic response to the migration of two-stage rifts: New insights into the late Neoproterozoic tectonics of the northern Tarim Craton

The spatiotemporal evolution of late Neoproterozoic sedimentary basins and their tectono-magmatic context provide essential information regarding the continental rift process of the Tarim Craton during the fragmentation of the Rodinia supercontinent. However, the incomplete exposure of strata and magmatism in the distal continental margin hinders the understanding of different rift phases that trigger continental breakup. The Sawapuqi region is currently located at the northernmost margin of the Tarim Craton and presents an uninterrupted sedimentary sequence and volcanic rocks from the latest Precambrian to the Cambrian period. Herein, we perform an integrated analysis of the Sawapuqi sub-basin and provide critical insights into the Ediacaran stratigraphic and tectono-magmatic evolution that shed light on the final rifting phase. The Sawapuqi sub-basin preserves regressive and transgressive successions, ranging from thick-bedded siltstones and siliceous rocks at the lower unit of the Sugetbrak Formation, through shore gravel-bearing laminated sandstone accumulation (upper unit), and restricted platform stromatolitic carbonates (Qigebrak Formation), to Cambrian mature passive margin sedimentation. An alkaline basaltic layer is interbedded within the coarsening-upward sedimentary packages of the early Ediacaran, recording the final rift-related magmatic pulse in the northwestern Tarim margin. The geochemical signatures of these basalts suggest a relatively shallow-depth derivation from the enriched mantle reservoir in an intraplate setting. The detrital zircon provenance of the coarse-grained siliciclastic to pebbly feldspathic debris sandstone sequence of the upper Sugetbrak Formation indicates the hybrid sediment infills from local metamorphic basements and Neoproterozoic igneous rocks, with progressively increased contribution from the coeval granites in the northern periphery of the Tarim Craton. The stratigraphic evolution from syn-rift clastic rocks to post-rift carbonates and the transition of detrital provenance observed in the Sawapuqi sub-basin suggest the development of a breakup succession at the end of the early Ediacaran period. The margin-localized continental extension and mantle-derived volcanism during the early Ediacaran differed from the distributed extension and bimodal magmatism during the Cryogenian, indicating two-stage extensional modes and subsidences prior to the lithospheric breakup. The rift system of the latter stage, which migrated oceanwards, eventually led to the continental breakup in the northwestern margin of the Tarim Craton. Comparable late Neoproterozoic stratigraphy and magmatic pulses between the Tarim Craton and Yili-Central Tianshan Block (YCTB) support their reconstructions as two conjugate rifted margins. This study indicates that the rift-drift tectonics triggered by this prolonged episodic rifting between the Tarim Craton and the YCTB was closely associated with the final fragmentation of Rodinia.

Stability and probabilistic assessment of a large asymmetric bedding slope with a weak interlayer.

The mining of open-pit mines has a significant influence on the surrounding ecological environment and safety. Once the slope of an open pit is unstable, it will bring extremely severe disasters to the surrounding environment. The south slope of the Fushun West open-pit mine is a large bedding slope with weak interlayer and asymmetrical features between the eastern and western regions. The different deformation mechanisms are worth further discussion, and the deformation mechanism of the eastern region needs to be systematically investigated. In this study, a comprehensive method combining a numerical model, the limit equilibrium method, and a probabilistic approach is used. The different deformation mechanisms of the slope are explored. Thereafter, the sensitivity of the geometric and mechanical parameters of the slope is determined. Finally, the probability of failure (PF) and slope stability are evaluated. The results illustrate that the difference in geological characteristics and constraint conditions is the fundamental reason for the difference in deformation features of the slope. The sensitivity analysis results show that the friction angle of the weak layer exhibits the most sensitivity and that the unit weight is irrelevant to the slope stability. Taking the friction angle of the weak layer as a variable, when thethickness of the basalt layer is less than 140 m and the height of the slope is more than 360 m, the PF of the slope reaches a high value. When the inclination of the weak layer exceeds 30°, the PF of the slope increases to a high value. When the Ru coefficient exceeds 0.2, the slope presents a high PF. The results illustrate that decision-makers should pay attention to the strength degradation, transitional mining of the basalt layer, and establish a good drainage system. The comprehensive method can also provide an effective way to assess the stability and PF of similar large-scale bedding slopes under complex geological conditions.

Mechanical and vibration behavior of surface‐modified titanium sheet interleaved with woven basalt/flax fiber metal laminates

AbstractIn fiber metal laminates (FMLs), the order in which fibers with different natural properties are stacked is very important for making materials that absorb vibrations and have good mechanical properties for structural applications. Hence, the present study focuses on the mechanical and vibration characteristics of FML designed with multi‐order energy‐absorbing flax fiber and high‐strength basalt fiber stacking covered with titanium sheets. The fabricated FMLs were designed with titanium/basalt fiber laminate (Ti/B), titanium/flax fiber laminate (Ti/F) and titanium/multi‐order‐flax‐basalt fiber laminate. The mechanical characteristics including tensile, flexural, and impact strength; and vibration characteristics of prepared FMLs were investigated. The higher tensile and flexural strength were revealed in an FML consisting of basalt layers (Ti/B) laminate than the flax core part (Ti/F) due to the strongness of basalt fiber, increasing the capability of load‐bearing of composites. Ti/B FML showed a maximum tensile strength and flexural strength of 412 and 450 MPa. Furthermore, flax fiber absorbs more energy, so the flax layer's inbuilt structure increases energy absorption during impact and vibration testing. Ti/F exhibits the highest impact strength (427.8 kJ/m2) and Ti/B exhibits the lowest impact strength (312.5 kJ/m2) because flax fibers are more ductile than basalt fibers, increasing the toughness of the FML. Ti/F FML structure, the greatest natural frequency of modes 1, 2, and 3 (549.03, 715.07, and 956.15 Hz) was observed. Natural fiber hybridization designed for FML, such as the Ti/B/F laminate, improved mechanical and vibration properties, making it suitable for structural applications.Highlights Fiber metal laminates were designed with titanium/flax/basalt. FMLs stacked composites significantly affect the mechanical properties. The basalt fiber, increases the capability of load‐bearing of FMLs. The damping of FMLs increases with the increase in flax fiber layers. Flax‐basalt fibers stacked FMLs produce tunable impact and vibration energy.

LASER MACHINING OF BASALT GLASS HYBRID COMPOSITE USING DEMATEL METHOD

Hybrid composites are materials made of two or more different types of fibers incorporated into a single polymer matrix the year 2019 publication failure analysis in bio composites, fiber-reinforced composites, and hybrid composites. A hybrid composition of basalt and glass layer fabricated and its various mechanical properties after being tested. Glass-fiber composite is a magnificence of fiber-reinforced polymer composites. Hybrid compounds are common ones two or more in the matrix combining different types of fiber products manufactured by various hybrid gave researchers compounds have many definitions. A laser machine is a target material that interacts with a laser beam it is a material removal process done by such a device that uses photon energy processing to the target object thermal or photochemical energy is carried in the form of removing the items directly and by melting evaporation elimination. Commercial, industrial, aeronautical, maritime, and recreational constructions can utilize hybrid composites for their main structural components. It offers a wide range of advantages in the aerospace sector, including strong impact resistance, outstanding fatigue and corrosion resistance, and both. A hybrid composite made of layers of basalt and glass has been created, and after that, its varied mechanical characteristics have been examined. It takes time to precisely machine these composite materials. The mechanical performance of the hybrid composite is decreased by a number of constraints in traditional machining, including fiber pullout, delamination, burr formation, matrix crack development, etc. These issues might result in a poorly machined surface. The decision-making trial and evaluation laboratory (DEMATEL) is regarded as an efficient technique for locating the causal links in a complex system. It focuses on assessing the interdependencies between elements and identifying the crucial ones using a visual structural model. Lamp current (amp), Pulse frequency (Hz), Cutting speed (mm/min), Pulse width (ms), Air pressure (bars). From the result, it is seen that Lamp current got the first rank whereas the Pulse width is having the lowest rank.

Lithospheric architecture beneath the Amsterdam-St. Paul plateau, Southern Indian Ocean using the integrated gravity, magnetic and seismological study

Evolution of the Amsterdam-St. Paul (ASP) plateau is debated as a consequence of the Kerguelen mantle plume interaction with the South-East Indian Ridge (SEIR) or related with a weaker ASP plume origin. We performed an integrated geophysical approach using gravity and magnetic modeling along with the joint inversion of Ps receiver function and Rayleigh wave group velocity dispersion data to determine the crustal architecture, and upper mantle structure below the plateau. The gravity-magnetic model revealed that the plateau is associated with three crustal layers as basaltic layer, gabbroic layer and underplated material underlain by sedimentary strata. Our models further suggests that beneath the ASP plateau the Moho depth varies from ∼6.6 to 18.0 km. Joint inversion of Ps receiver function and Rayleigh wave group velocity dispersion curve suggested the Lithosphere-Asthenosphere Boundary at depth of 50 km below the Amsterdam Island. Further seismological result suggests evidence of a Low Velocity Zone below the Moho at depth of 20–36 km which may represent a magma chamber. Our model suggests that the evolution of the ASP plateau is guided by the Amsterdam and St. Paul fracture zones, which acted as a thermal boundary confining the horizontal movement of the ASP plume. We propose that the ASP plateau is not linked with the Kerguelen plume and emphasize origin of the ASP plateau by the interaction of SEIR with the ASP plume.

Quantifying the effect of grain size on weathering of basaltic powders: Implications for negative emission technologies via soil carbon sequestration

Weathering of basaltic powders was studied experimentally at 35 °C in dilute solutions of oxalic acid and carbonic acid to assess the effect of grain size and reactive surface area for materials under consideration for carbon dioxide reduction (CDR) by enhanced rock weathering (ERW). The basalts chosen for this study (with their mineralogical compositions) are the Blue Ridge (BR) meta-basalt (chlorite > epidote > plagioclase > actinolite) and Pioneer Valley (PV) basalt (plagioclase > augite > quartz > chlorite). Powders of BR and PV basalts were sieved into <45 μ m, 45–150 μ m, and >150 μm fractions, and experiments were performed in open-system reactors designed to simulate a 1 mm thick layer of basalt added to agricultural soil in the humid tropics. Weathering rate was assessed by measuring the flux of base cations leached from silicate minerals and results indicate that silt-dominated basaltic powder (<45 μ m) weathers at approximately double the rate of sand dominated (150–500 μ m) basaltic powder, both for the BR and PV basalts. This study estimates CDR rates between 2.8 and 6.8 t CO2/ha/yr across the range of grain size fractions analyzed. Etched primary mineral grains (e.g. plagioclase, augite, actinolite) with depleted base cations observed by SEM-EDS provide morphological and stoichiometric evidence of dissolution, as do the presence of frayed chlorite grains that contain adsorbed Ca and are compositionally intermediate to end-member chlorite and smectite. Small amounts of micron-scale calcite were also observed as a precipitate on mineral surfaces, likely a consequence of localized saturation of Ca and HCO3 in the matrix of the weathering powders. The results of this study help to constrain differences in weathering flux as a function of grain size, with important implications for effectiveness of CDR via ERW.

Moon Diver: Exploring a pit's exposed strata to understand lunar volcanism

Natural pits on the Moon expose deep cross-sections of the lunar maria, enabling direct investigation of the Moon's volcanic history and providing potential access to subsurface lava tubes. The Moon Diver mission concept seeks to explore the Mare Tranquillitatis pit, which exposes the largest wall of bedrock of the mare pits (∼65 m). The concept is enabled by two innovative capabilities: pinpoint landing near the pit and robotic access to its near-vertical wall with an instrument package to examine the elemental chemistry, mineralogy, and morphology of these bedrock layers. Pinpoint landing uses closed-loop guidance with terrain-relative navigation (TRN), which was advanced by Perseverance landing on Mars, to deliver the lander within a 100-m ellipse. The Axel robotic explorer, which remains tethered to the lander, would egress onto the lunar surface and traverse the relatively flat terrain to the pit's funnel entrance. The lander, which is the data link to Earth, also serves as an anchor and provides power and communication to the rover through its tether. The rover is a novel two-wheeled platform with a trailing boom and a spool that pays out the tether as the rover traverses toward the pit. The 300-m long tether is well margined for the rover to scale the pit wall. The rover carries a surface preparation tool and three additional instrument types: (a) three high-resolution cameras for acquiring context images of the near and far walls with the near-wall pair in a stereoscopic configuration, (b) an alpha-particle-X-ray spectrometer (APXS) for elemental composition, and (c) a multi-spectral microscopic imager (MMI) that uses controlled lighting for mineralogy. The surface-preparation tool removes dust and patina from the rock wall by grinding a small area. This tool, the MMI, and the APXS would be deployed from an instrument bay inside the wheel wells. The rover would independently point each instrument at the same target on the wall with millimeter repeatability. Landing shortly after sunrise, the surface mission timeline is just shy of a lunar daytime (14 Earth days). Beyond the primary mission, the rover would be capable of descending from the overhang and peering into the void that may open to a large cave or lava tube. Lunar pits provide an exciting new target for exploration using innovative robotic capabilities that have been tested with integrated science instruments at multiple terrestrial analogue sites including a pit with basaltic layers in Arizona.