Search Results (1,204)

The ion-adsorption-type rare earth element (iREE) deposits dominantly supply global resources of the heavy rare earth elements (HREEs), which have a critical role in a variety of advanced technological applications. The initial enrichment of REEs in the parent granites controls the formation of iREE deposits. Many Mesozoic and Cenozoic granites are associated with iREE mineralization in the Tengchong block, Southwest China. However, it is unclear how vital the mineralogical and geochemical characteristics of these granites are to the formation of iREE mineralization. We conducted geochronology, geochemistry, and Hf isotope analyses of the Yingpanshan–Damanbie granitoids associated with the iREE deposit in the Tengchong block with the aims to discuss their petrogenesis and illustrate the process of the initial REE enrichment in the granites. The results showed that the Yingpanshan–Damanbie pluton consists of syenogranite and monzogranite, containing REE-bearing accessory minerals such as monazite, xenotime, apatite, zircon, allanite, and titanite, with a high REE concentration (210–626 ppm, mean value is 402 ppm). The parent granites have Zr + Nb + Ce + Y (333–747 ppm) contents and a high FeO^T/MgO ratio (5.89–11.4), and are enriched in Th (mean value of 43.6 ppm), U (mean value of 4.57 ppm), Zr (mean value of 305 ppm), Hf (mean value of 7.94 ppm), Rb (mean value of 198 ppm), K (mean value of 48,902 ppm), and have depletions of Sr (mean value of 188 ppm), Ba (mean value of 699 ppm), P (mean value of 586 ppm), Ti (mean value of 2757 ppm). The granites plot in the A-type area in FeO^T/MgO vs. Zr + Nb + Ce + Y and Zr vs. 10,000 Ga/Al diagrams, suggesting that they are A₂-type granites. These granites are believed to have formed through the partial melting of amphibolites at a post-collisional extension setting when the Tethys Ocean closed. REE-bearing minerals (e.g., apatite, titanite, allanite, and fluorite) and rock-forming minerals (e.g., potassium feldspar, plagioclase, biotite, muscovite) supply rare earth elements in weathering regolith for the Yingpanshan–Damanbie iREE deposit. Full article

Lithium-ion batteries (LIBs) have significantly advanced portable electronics, yet their reliance on flammable organic solvents and lithium dendrite formation pose safety risks. Solid-state batteries (SSBs), utilizing solid electrolytes, offer a safer alternative with higher energy and power densities. This study explores the fabrication of solid electrolytes using ceramic stereolithography, focusing on lithium lanthanum zirconate (LLZ) due to its high ionic conductivity and chemical stability. A photosensitive paste containing 40–43 vol% LLZ was suitable for processing by stereolithography, and optimized processing parameters of 100 mW laser power and 1000 mm/s laser scanning speed with a 50 μm laser spot size were identified for sufficient material curing and interlayer lamination of LLZ. Thin embossed sheets were designed to enhance ion exchange and reduce internal resistance and were fabricated by the ceramic stereolithography method. The effect of cold isostatic pressing (CIP) on the sintered microstructure was investigated, and the potential for CIP to promote solid-phase diffusion during sintering was demonstrated, particularly at 67 MPa. The resulting LLZ-embossed sheets exhibited dense ceramic microstructures. These findings support the potential application of ceramic stereolithography for fabricating efficient solid electrolytes for next-generation telecommunications and mobile devices. Full article

A unique Li–Na metasomatic rock from Iwagi Islet in Southwest (SW) Japan is an episyenite that contains new Li-rich minerals, including sugilite, katayamalite, murakamiite, and ferro-ferri-holmquistite. We present petrographical, mineralogical, and geochronological data for the protoliths and episyenite. We classified the metasomatic rocks based on the mineral assemblages, from the protolith biotite granite to albitized granite, quartz albitite, hedenbergite albitite, aegirine albitite, sugilite albitite, and katayamalite albitite. The protolith of hedenbergite albitites may have been metasomatic granite that has been subjected to calcic skarnization. Albitites are formed related to fractures and shear zones that focused the fluid flow and metasomatism. Extensive albitization and formation of abundant Li minerals requires involvement of external Li-Na-Cl-rich fluids, which might be related to deep high-temperature Arima-like brines derived from dehydration of the subducted oceanic slab. Formation of the albitites began with quartz dissolution and vug formation, and record interface-coupled dissolution–reprecipitation processes in an open system. The ⁴⁰Ar/³⁹Ar age of 91.5 ± 0.3 Ma determined for the katayamalite is slightly younger than the protolith zircon U–Pb age of 93.5 ± 1.7 Ma (Turonian), reasonably explaining the timing of Li–Na metasomatism after the petrogenesis of host granites. Full article

Stabilized Li_6.25La₃Al_0.25 Zr₂O₁₂ (cubic LLZO or c-LLZO) is a Li⁺-conducting ceramic with ionic conductivities approaching 1 mS-cm. Processing c-LLZO so that it is suitable for use as a solid state electrolyte in all solid state batteries, however, is challenging due to the formation of secondary phases at elevated temperatures. The work described in this manuscript examines the formation of one such secondary phase La₂Zr₂O₇ (LZO) formed during sintering c-LLZO at 1000 °C. Specifically, spatially resolved Raman spectroscopy and X-ray Diffraction (XRD) measurements have identified gradients in Li distributions in the Li ion (Li⁺)-conducting ceramic Li_6.25La₃Al_0.25 Zr₂O₁₂ (cubic LLZO or c-LLZO) created by thermal processing. Sintering c-LLZO under conditions relevant to solid state Li⁺ electrolyte fabrication conditions lead to Li⁺ loss and the formation of new phases. Specifically, sintering for 1 h at 1000 °C leads to Li⁺ depletion and the formation of the pyrochlore lanthanum zirconate (La₂Zr₂O₇ or LZO), a material known to be both electronically and ionically insulating. Circular c-LLZO samples are covered on the top and bottom surfaces, exposing only the 1.6 mm-thick sample perimeter to the furnace’s ambient air. Sintered samples show a radially symmetric LZO gradient, with more LZO at the center of the pellet and considerably less LZO at the edges. This profile implies that Li⁺ diffusion through the material is faster than Li⁺ loss through volatilization, and that Li⁺ migration from the center of the sample to the edges is not completely reversible. These conditions lead to a net depletion of Li⁺ at the sample center. Findings presented in this work suggest new strategies for LLZO processing that will minimize Li⁺ loss during sintering, leading to a more homogeneous material with more reproducible electrochemical behavior. Full article

The main ocean–continent transformation stage of the Qinling and Qilian conjunction zone happened in the Early Paleozoic with the occurrence of a lot of subduction–collision–related magmatic rocks. However, there is still considerable controversy over the duration of the subduction–collision orogeny process of the Proto-Tethys Ocean, here termed as the Wushan–Shangdan Ocean. We provide geochronological, geochemical, and Lu-Hf isotopic data for typical Early Devonian igneous rocks there, named Tailu pluton. The Tailu pluton at 410 Ma comprised K-rich, calc-alkaline, metaluminous A-type granite with low Y/Nb ratios (0.85 to 1.35) and A/CNK values (0.90 to 1.01); with high SiO₂ contents (65.44 to 74.46 wt%), Mg^# values (39.2 to 50.7), and zircon saturation temperatures (745 to 846 °C); and with negative ε_Hf (t) values (−8.0 to −1.9); therefore, they resulted from the partial melting of the ancient felsic lower crust accompanied by the incorporation of mantle-derived material during the intraplate magmatism process. Research on Tailu pluton has provided more sufficient evidence for the evolution process of the Qinling–Qilian conjunction zone in the Early Paleozoic, associated with evolution of the Wushan–Shangdan Ocean, the northern part of the Proto-Tethys Ocean. Full article

The Songpan–Ganzi Orogenic Belt (SGOB) is bounded by the South China, North China, and Qiangtang blocks and forms the eastern margin of the Tibetan Plateau. The Tiechanghe Granite is located at the junction of the southeast margin of the SGOB and the western margin of the Yangtze Block. To elucidate the genetic relationship between the Tiechanghe Granite and the surrounding molybdenum deposits in Western Sichuan, in this study, we conducted zircon U-Pb and molybdenite Re-Os isotopic dating. The results indicate that the Tiechanghe Granite predominantly consists of monzogranite, with minor occurrences of syenogranite, while the molybdenum deposits are mainly found in skarn and quartz veins. The laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U-Pb ages of the Tiechanghe Granite range from 162.9 ± 0.7 Ma (MSWD = 0.31, n = 25) to 163.4 ± 0.6 Ma (MSWD = 0.85, n = 26), and the LA-ICP-MS zircon U-Pb age of the pegmatite veins is 164.1 ± 0.9 Ma (MSWD = 1.3, n = 19). These ages are consistent with the weighted average Re-Os age of the Ziershi molybdenite (160.3 ± 1.6 Ma, n = 2) within the error margins. These findings and previously obtained magmatic and metallogenic ages for the region suggest that a magmatic and mineralization event involving granite, molybdenum, tungsten, and copper occurred at around 162–164 Ma in the study area. This discovery broadens the exploration perspective for mineral resources in the Jiulong area of Western Sichuan and the entirety of Western Sichuan. Full article

Real-time structural health monitoring (SHM) and accurate diagnosis of imminent damage are critical to ensure the structural safety of conventional reinforced concrete (RC) and fiber-reinforced concrete (FRC) structures. Implementations of a piezoelectric lead zirconate titanate (PZT) sensor network in the critical areas of structural members can identify the damage level. This study uses a recently developed PZT-enabled Electro-Mechanical Impedance (EMI)-based, real-time, wireless, and portable SHM and damage detection system in prismatic specimens subjected to flexural repeated loading plain concrete (PC) and FRC. Furthermore, this research examined the efficacy of the proposed SHM methodology for FRC cracking identification of the specimens at various loading levels with different sensor layouts. Additionally, damage quantification using values of statistical damage indices is included. For this reason, the well-known conventional static metric of the Root Mean Square Deviation (RMSD) and the Mean Absolute Percentage Deviation (MAPD) were used and compared. This paper addresses a reliable monitoring experimental methodology in FRC to diagnose damage and predict the forthcoming flexural failure at early damage stages, such as at the onset of cracking. Test results indicated that damage assessment is successfully achieved using RMSD and MAPD indices of a strategically placed network of PZT sensors. Furthermore, the Upper Control Limit (UCL) index was adopted as a threshold for further sifting the scalar damage indices. Additionally, the proposed PZT-enable SHM method for prompt damage level is first established, providing the relationship between the voltage frequency response of the 32 PZT sensors and the crack propagation of the FRC prisms due to the step-by-step increased imposed load. In conclusion, damage diagnosis through continuous monitoring of PZTs responses of FRC due to flexural loading is a quantitative, reliable, and promising application. Full article

The Baoshan Cu-Pb-Zn deposit is situated at the intersection of the Qin-Hang Cu polymetallic and Nanling W-Sn polymetallic metallogenic belts. The age, lithology, petrogenesis, and tectonic setting of granodiorite porphyry within the deposit remain subjects of debate. Additionally, there is a lack of comparative studies with the W-Sn-related granites in the region. This study conducted whole-rock major and trace element analysis, Sr-Nd isotope analysis, and zircon U-Pb dating on the Baoshan granodiorite porphyry. The zircon U-Pb age of the granodiorite porphyry is 162 ± 1 Ma. The whole-rock SiO₂ and K₂O contents range from 65.87 to 68.21 wt.% and 3.42 to 5.62 wt.%, respectively, indicating that the granodiorite porphyry belongs to high-potassium calc-alkaline I-type granite. The granodiorite porphyry is characterized by enrichment in LREE and depletion in HREE (LREE/HREE ratio = 6.2–21.2). The samples of granodiorite porphyry generally exhibit weak negative Eu anomalies or no Eu anomalies (δEu = 0.62–1.04, mean = 0.82). The (⁸⁷Sr/⁸⁶Sr)_i and ε_Nd(t) values are 0.707717–0.709506 and −7.54 to −4.87, respectively. The whole-rock geochemical composition and Sr-Nd isotopic values indicate that the magma originated from the partial melting of the Mesoproterozoic ancient crust and Neoproterozoic mafic juvenile lower crust, with the addition of high oxygen fugacity and water-rich lithospheric mantle melts. The source of the granodiorite porphyry in the Baoshan deposit is significantly different from the crust-derived metapelite source of the W-Sn-related granite in the area, indicating that different magma sources might be the main reason for the co-spatial and nearly contemporaneous development of Cu-Pb-Zn and W-Sn mineralization in the southern Hunan region. Full article

Ionic polymer metal composite (IPMC) is regarded as the mainstream application material for achieving flexible driving technology in various engineering fields. In this article, aiming at the non-independence of the current IPMC electric driving method, an IPMC optical-controlled flexible driving method based on the photoinduced effects of lanthanum-modified lead zirconate titanate (PLZT) ceramic is proposed. To this end, a mathematical model for IPMC optical controlled flexible driving is built on the basis of the photovoltaic characteristic of PLZT ceramic, and the driving performance is experimentally analyzed through different lengths of IPMC under the excitation of different direct currents and light intensities. From the analysis and experimental results, when PLZT ceramic is irradiated by different light intensities, the output deformation of IPMC increases with increases in light intensity, and finally reaches a stable state. Moreover, the actuation curves obtained by light excitation and direct current excitation are consistent, and the motion coefficient reflects the driving performance more accurately. In addition, using light energy as an excitation source to drive IPMC not only provides new ideas for its development in the flexible driving field, but also provides a theoretical basis for its practical application. Full article

The Xifanping deposit is a distinct Cenozoic porphyry Cu (Au) deposit located in the Sanjing porphyry metallogenic belt 100–150 km east of the JinshajFiang fault in the western Yangtze craton. We present new zircon U–Pb–Lu–Hf isotopic studies and geochemical data of the ore-bearing quartz monzonite porphyry from the Xifanping deposit to determine their petrogenesis and geodynamic mechanisms. LA–ICP–MS zircon U–Pb dating yielded precise emplacement ages of 31.87 ± 0.41 Ma (MSWD = 0.86) and 32.24 ± 0.61 Ma (MSWD = 1.8) for quartz monzonite porphyry intrusions, and 254.9 ± 5.1 Ma (MSWD = 1.7) for inherited zircons of the monzonite porphyry. The ore-bearing monzonite porphyry is characterized by high-K calc–alkaline to shoshonite and peraluminous series, relatively enriched in light over heavy REEs, with no distinct Eu anomalies, as well as enrichment in LILEs and depletion of HFSEs, with adakitic affinities. The zircon Lu–Hf isotope data ranged from εHf(t) values of −2.94 to +3.68 (average −0.47) with crustal model (T_DM2) ages ranging from 0.88 to 1.30 Ga, whereas the inherited zircons displayed positive εHf(t) values ranging from +1.83 to +7.98 (average +5.82), with crustal model (T_DM2) ages ranging from 0.77 to 1.17 Ga. Results suggest that the Xifanping porphyry Cu (Au) deposit is related to two periods of magmatic activities. Early magmas were generated from the Paleo-Tethys oceanic subduction during the Late Permian. The subsequent porphyry magma was likely formed by the remelting of previously subduction-modified arc lithosphere, triggered by the continental collision between the Indian and Asian plates in the Cenozoic. The deep magmas and late hydrothermal fluids took advantage of the early magma transport channels along tectonically weak zones during the transition from an extrusive to an extensional–tensional tectonic environment. Early dikes from remelted and assimilated crust contributed to the two age ranges observed in the porphyry intrusions from the Xifanping deposit. The juvenile lower crust materials of the early magmatic arc were potential sources of the Cenozoic porphyry magmas, which has significant implications for mineral exploration and the geological understanding of porphyry Cu deposits in this region. Full article

The ultramafic rock located on the northern slope of Lüliang Mountain in the northwestern region of North Qaidam Orogen is altered to serpentinite. The occurrence of disseminated chromite within the serpentinite holds significant implications for understanding the petrogenesis of the protolith. This work provides strong evidence of a distinct zonal texture in the chromite found in the ultramafic rock, using petrographic microstructure and electron probe composition analysis. The core of the chromite is characterized by high contents of Cr^#, with enrichment in Fe^3+# (Fe³⁺/(Cr + Al + Fe³⁺)) and depletion in Al₂O₃ and TiO₂. The Cr₂O₃ content ranges from 51.64% to 53.72%, while the Cr^# values range from 0.80 to 0.84. The FeO content varies from 24.9% to 27.8%, while the Fe₂O₃ content ranges from 5.19% to 8.74%. The Al₂O₃ content ranges from 6.70% to 9.20%, and the TiO₂ content is below the detection limit (<0.1%). Furthermore, the rocks exhibit Mg^# values ranging from 0.13 to 0.25 and Fe^3+# values ranging from 0.07 to 0.12. The mineral chemistry of the chromite core in the ultramafic rock suggests it to be from an ophiolite. This ophiolite originated from the fore-arc deficit asthenosphere in a supra-subduction zone. The estimated average crystallization temperature and pressure of the chromite are 1306.02 °C and 3.41 GPa, respectively. These values suggest that the chromite formed at a depth of approximately 110 km, which is comparable to that of the asthenosphere. The chromite grains are surrounded by thick rims composed of Cr-rich magnetite characterized by enrichment in Fe^3+# contents and depletions in Cr₂O₃, Al₂O₃, TiO₂, and Cr^#. The FeO content ranges from 28.25% to 31.15%, while the Fe₂O₃ content ranges from 44.94% to 68.92%. The Cr₂O₃ content ranges from 0.18% to 23.59%, and the Al₂O₃ and TiO₂ contents are below the detection limit (<0.1%). Moreover, the rim of the Cr-rich magnetite exhibits Cr^# values ranging from 0.90 to 1.00, Mg^# values ranging from 0.01 to 0.06, and Fe^3+# values ranging from 0.64 to 1.00, indicating late-stage alteration processes. The LA-ICP-MS zircon U-Pb dating of the ultramafic rock yielded an age of 480.6 ± 2.4 Ma (MSWD = 0.46, n = 18), representing the crystallization age of the ultramafic rock. This evidence suggests that the host rock of chromite is an ultramafic cumulate, which is part of the ophiolite suite. It originated from the fore-arc deficit asthenosphere in a supra-subduction zone during the northward subduction of the North Qaidam Ocean in the Ordovician period. Furthermore, clear evidence of Fe-hydrothermal alteration during the post-uplift-denudation stage is observed. Full article

The Mengshan granitoid complex is located in the central part of Jiangnan Orogen and belongs to the western part of Jiangxi Province, where several phases of granitic magmatism record the crustal evolution of the late-Indosinian. However, its petrogenesis remains uncertain, largely due to controversies over its origin, evolutionary process and tectonic setting during intrusion. In this study, the lithological features and contact relationships observed in the systematic field geological investigations indicate that the late magmatic phases of the Mengshan granitoid complex are mainly composed of medium–fine-grained biotite monzogranite and fine-grained monzogranite, both of which developed primary fine-grained muscovite. Petrological, petrographic, geochemical and zircon U-Pb-Hf isotopic studies were further carried out on these rocks. Zircon U-Pb isotopic analyses suggest that the medium–fine-grained biotite monzogranite mainly formed at 220.7 ± 1.0 Ma to 218.0 ± 0.8 Ma, and that the fine-grained monzogranite formed at 211.5 ± 2.9 Ma to 212.9 ± 1.0 Ma. Whole-rock geochemical analysis results suggest that these rocks are rich in Cs, Rb, and U, and deficient in Ba, Sr, and Ti, and that they have properties characteristic of rocks with high silica, low P content and high K calc-alkali. Mineralogical and geochemical analysis results suggest that they are S-type granites. The ε_Hf(t) values of the early-stage medium–fine-grained biotite monzogranite and late-stage fine-grained monzogranite range from –4.7 to 0.3 and from –3.2 to 0.7, respectively. Geochemical and isotopic data suggest that these granitoids were derived from the partial melting of Proterozoic continent basement rocks, and that minor mantle materials were involved during their generation. The presence of the early Mesozoic Mengshan granitoid complex reflects a reduplicated far-field converge effect of the collision of the North China and South China blocks and the subduction of the Palaeo-Pacific plate into the South China block. The thickening of the Earth’s crust facilitated crustal delamination, underplating of mantle-derived magma, and crustal heating, triggering intense partial melting of the lithosphere and magma enrichment. Full article

The Zhegu area in southern Tibet is situated in the central and eastern part of the Tethys Himalayan tectonic belt, with the Kangbuzhenri area being abundant in gneissic granites. This study examines the petrology, chronology, and geochemistry of the Kangbuzhenri gneissic granite, providing insights into its Pan-African and Early Paleozoic geological evolution. The zircon U-Pb chronology indicates an upper intercept age of ~539 Ma, reflecting Pan-African orogenic events in the eastern part of the Tethys Himalayan tectonic belt, and a lower intercept age of ~144 Ma, representing a late tectonic–thermal event. Geochemically, the gneissic granites are calc-alkaline peraluminous rocks with high SiO₂ and Al₂O₃ contents and low TiO₂, P₂O₅, MgO, and FeO^T contents. The gneissic granites are enriched in LREE and LILEs (Rb, Pb, Th, U, etc.), but relatively depleted in HREE and HFSEs (Nb, Ti, P, etc.). Most of them show a weak negative δEu anomaly, except for two samples which show a significant negative δEu anomaly due to the crystallization of plagioclase. Based on the above study, most of the gneissic granites exhibited the characteristics of an I-type granite, while two of the samples were a highly differentiated I-type granite with S-type affinities. All the above characteristics indicate that the gneissic granite likely originated from the partial melting of crustal materials and sediments with a minor involvement of mantle-derived materials. Combined with the previous chronological studies, the Kangbuzhenri gneissic granites were formed in an extensional tectonic environment during post-collision orogeny and then they were influenced by the Kerguelen mantle plume tectonic–thermal event around ~144 Ma and the subsequent Southern Tibet Detachment System (STDS). Full article

The Mesozoic subduction zone over the Dongsha Waters (DSWs) of the South China Sea (SCS) is a part of the westward subduction of the ancient Pacific plate. Based on the comprehensive interpretation of deep reflection seismic profile data and polar magnetic anomaly data, and the zircon dating results of igneous rocks drilled from well LF35-1-1, the Mesozoic subduction zone in the northeast SCS is accurately identified, and a Mesozoic subduction model is proposed. The accretion wedges, trenches, and igneous rock zones together form the Mesozoic subduction zone. The evolution of the Mesozoic subduction zone can be divided into two stages: continental subduction during the Late Jurassic and continental collision during the late Cretaceous. The Mesozoic subduction zone controlled the structural pattern and evolution of the Chaoshan depression (CSD) during the Mesozoic and Neogene eras. The gas source of the hydrate comes from thermogenic gas, which is accompanied by mud diapir activity and migrates along the fault. The gas accumulates to form gas hydrates at the bottom of the stable domain; BSR can be seen above the mud diapir structure; that is, hydrate deposits are formed under the influence of mud diapir structures, belonging to a typical leakage type genesis model. Full article