Accurate prediction of natural resource prices plays a significant role in national economic development. However, existing research often focuses solely on same-frequency forecasting, neglecting the rich information contained in high-frequency data. To bridge this gap and explore whether mixed-frequency prediction improves the forecasting performance, this study develops an innovative mixed-frequency deep learning forecasting model grounded in Pearson correlation coefficient analysis, long-short-term memory, particle swarm optimization, and mixed-frequency data sampling regression. Taking copper price as an example, this study first applies Pearson correlation analysis to select the most relevant influencing factors from mixed-frequency variables. These factors include policy uncertainty, macroeconomic conditions, energy costs, and other non-ferrous metal prices. Subsequently, the proposed mixed-frequency deep learning model is used for predicting copper price. Experiments include comparisons with the benchmark model, multi-step prediction, statistical hypothesis testing, in-depth evaluation of forecasting effectiveness, and robustness analysis. The final experimental results demonstrate that the proposed mixed-frequency deep learning model significantly outperforms the comparison models, effectively improving prediction accuracy. This study not only expands the scope of futures price prediction research, but also provides a new perspective for time series prediction work in other fields.

The closure age of the Proterozoic Vindhyan basin is a long-standing puzzle, unresolved due to inconsistencies between paleontological, geochronological, and paleomagnetic data. Some fossil findings from the Upper Vindhyan basin suggest an Ediacaran closure age, Pb-Pb dating of carbonate units yield dates ranging from ∼ 750-910 Ma, and detrital zircon data generally support a Kleisian (800-1000 Ma) closure age. In this study, we review published detrital zircon data and apply a statistically robust method to estimate the maximum depositional age (MDA) of the upper Vindhyan Kaimur, Bhander, and Rewa groups. Additionally, we present new paleomagnetic data from the folded Bhander sandstones near the Great Boundary fault to establish the primary nature of the Bhander-Rewa paleomagnetic pole. Our analysis reveals an MDA of 945 ± 7 Ma, which aligns closely with the youngest zircon population in the spectra. This MDA also corresponds to the onset of the Delhi Orogeny to the west of the Vindhyan basin; collisional orogenesis in the Central Indian Tectonic Zone to the south; and more distal high-grade metamorphism and collisional tectonism in the northern Eastern Ghats belt providing a geologically meaningful context for the basin closure age. Our paleomagnetic data offers a robust field test for the Vindhyan pole and we demonstrate that proposals for terminal Tonian closure of the basin ( ∼ 850-770 Ma) are incompatible with extant paleomagnetic data from India.

We investigate Earth’s evolution through thermally coupled core-mantle models spanning 4.5 billion years. These models employ a spherical pseudo-spectral approach to solve the conservation equations for mass, momentum, and energy within a compressible, self-gravitating mantle. The methodology incorporates time-dependent treatments for core-mantle coupling, dislocation and diffusion creep mechanisms, internal heating, and thermal conductivity. Using 3-D numerical simulations, we evaluate the sensitivity of mantle cooling, viscosity structure, and inner-core growth to variations in lithospheric viscosity, diffusion viscosity, mechanical surface boundary conditions, and initial core-mantle boundary and core liquidus temperatures. Results underscore the central role of lithospheric viscosity, particularly near an effective value of ∼ 10²² Pa s, in producing a mantle cooling pattern consistent with petrological constraints, characterized by net warming prior to ∼ 3 billion years ago (Ga) followed by long-term cooling, as predicted by low-Urey-ratio thermal evolution models. Notably, one model with lithospheric viscosity allowed to vary between 10¹⁸ and 10²⁴ Pa s exhibits nonlinear rheological feedbacks that trigger an early-stage thermal rebound. This behavior results from a relatively abrupt increase in lithospheric viscosity which redirects the mantle onto a sustained warming trajectory that departs from the expected monotonic cooling. This example also demonstrates how nonlinear parameter interactions can produce non-monotonic thermal evolution. However, lithospheric viscosity alone cannot fully account for present-day observations of heat flux, inner-core radius, and depth-dependent viscosity profiles. We find that varying the activation enthalpy ratio for grain-growth-controlled diffusion viscosity modifies the radial viscosity structure while leaving the overall cooling pattern intact. Furthermore, surface boundary conditions permitting viscous coupling between rigid surface plates and underlying mantle flow — specifically in our plate-like (PL) model — yield the most acceptable mantle cooling rates and dynamic evolution. This PL configuration also facilitates more realistic coupling between surface kinematics and internal convection, allowing plate velocities to emerge from the flow dynamics rather than being imposed. The PL model exhibits patterns which are similar to independently estimated present-day mantle viscosity profiles, including features such as the lithosphere-asthenosphere gradient and the viscosity jump at the 660 km discontinuity. The PL model also exhibits persistent large-scale lateral temperature anomalies, consistent with previous billion-year convection studies, and illustrates how plate-like surface coupling promotes the emergence and maintenance of hemispheric-scale heterogeneity. Findings confirm that initial core-mantle boundary temperature and liquidus temperature at the inner-core boundary significantly influence inner-core growth rates. To isolate the effects of the initial thermal state of the core, we adopt a simplified initialization in which the liquidus temperature is set equal to the core-mantle boundary (CMB) temperature at time zero — this condition is imposed only at initialization. For the PL model, initializing both the CMB temperature and the inner-core liquidus temperature at 5600 K optimizes predictions of present-day inner-core radius and suggests an inner-core onset around 2.0 ‒ 1.5 Ga, aligning with previous independent estimates. This study emphasizes that a robust modeling of Earth’s core-mantle thermal and dynamic history requires careful calibration of lithospheric viscosity and grain-size-sensitive mantle viscosity, surface boundary dynamics, and initial temperatures at the CMB and core liquidus. All model predictions are empirically anchored and evaluated against a wide thermal evolution. By enabling a broad exploration of the parameter space — incorporating complex rheology and a viscosity range spanning 12 orders of magnitude — these tools facilitate sensitivity analyses and the refinement of parameter constraints. However, the complexity of the coupled core-mantle system highlights the need for continued refinement of computational techniques to fully capture planetary evolution. Furthermore, while primarily designed for Earth, the methodology can be adapted — with appropriate modifications — to study telluric planets in our solar system and Earth-like exoplanets, advancing our understanding of planetary evolution across diverse contexts.

This study investigates the petrological and metasomatic processes that lead to carbon enrichment in peridotites from Sal Island, Cape Verde. Geochemical and mineralogical analyses reveal a heterogeneous lithospheric mantle, consisting of harzburgites showing ultrarefractory compositions indicative of 20%-40% melting degrees, as well as fertile spinel lherzolites. Evidence of metasomatism is demonstrated by the formation of reaction coronae around dissolving orthopyroxene, consisting of olivine, clinopyroxene, spinel, and interstitial phonolitic glass, together with trachytic/phonolitic glass + carbonate (calcite, aragonite, and dolomite) microveins associated with CO₂ fluid-rich melt inclusions (Type I and II) cutting through olivine and orthopyroxene. The widely differing proportions of silicate and carbonate components in inclusions likely reflect heterogeneous trapping of melt/fluid and degassing CO₂. Thermobarometric data indicate equilibration temperatures from 950 to 1060 °C in harzburgites and up to 1200 °C for reaction coronas in harzburgites and lherzolites, with pressures reaching the aragonite stability field ( ∼ 2.2-3.5 GPa, or 66-106 km depth). These observations indicate the infiltration at the base of the lithosphere of a silicate-carbonate melt enriched in alkalies, Al, and volatiles (Cl, S, F, N, P). In microveins, the silicate glass composition (e.g., K and Ti content) is consistent with experimental partial melts derived from carbonated sediments with a minor addition of a carbonated eclogite. Enrichments in major and trace elements in clinopyroxene in harzburgites and lherzolites suggest at least two significant metasomatic events involving alkali-rich silicate-carbonate melts at the base of the lithosphere, and CO₂-rich fluid, alkali-rich silicate melts in the deep lithosphere, close to pressure conditions of the carbonate ledge. The introduction of recycled carbon into the upper mantle beneath the Cape Verde archipelago likely occurred during the multiple subduction events that affected the region in the half a billion years leading to the Pangea assembly. Major mobilisation of crustal components, generation of carbonate-rich melts, and subsequent lithospheric metasomatism were triggered by the Oligocene thermal perturbation associated with the Cape Verde mantle plume.

Submarine hydrothermal activities release a large amount of greenhouse gases such as CO₂ and CH₄ into the ocean, influencing the global carbon cycle. Carrying out high-temperature and high-pressure hydrothermal experiments to simulate these geochemical processes is a prerequisite for clarifying the source of carbon-containing substances in the hydrothermal fluid. In situ monitoring of the change in carbon isotope composition of CO₂ is essential for high-temperature and high-pressure simulation experiments, but it is also a great technical challenge. In recent years, laser Raman spectroscopy has attracted wide attention as a supplementary means to mass spectrometry for measuring the ¹³C/¹²C value of CO₂. However, the existing research is limited to the Raman spectroscopy study of the carbon isotope composition of supercritical/liquid CO₂, and there is little research on dissolved CO₂ in solution. In this study, we systematically studied the Raman spectral characteristics of dissolved ¹³CO₂ and ¹²CO₂ in the H₂O ± ¹³CO₂ ± ¹²CO₂ system at 25-300 °C and 10-350 bar. The results show that the peak position of the Raman characteristic band of ¹³CO₂ (aq) is 1367-1370 cm⁻¹, which is 14-17 cm⁻¹ lower than that of ¹²CO₂ (aq), and the full width at half maximum is 2-3 cm⁻¹ smaller than that of ¹²CO₂, which indicate the ¹³CO₂ (aq) and ¹²CO₂ (aq) can be identified by Raman spectroscopy. On this basis, we proposed the optimal likelihood curve fitting method (OLCF) for the first time to decompose the overlapping bands and accurately obtain the peak height ratio (H₁₃/H₁₂) of dissolved ¹³CO₂ and ¹²CO₂. It has been shown that the G-factor ratios (G₁₃/G₁₂) are significantly affected by temperature and the relative content of ¹³CO₂ and ¹²CO₂. Obtaining an appropriate G-factor ratio is a prerequisite for accurately determining the ¹³C/¹²C of dissolved CO₂. Based on the functional relationship between the H₁₃/H₁₂ and the ¹³C/¹²C, we established an empirical equation to quickly estimate the ¹³C/¹²C value, thereby assisting in selecting an appropriate G-factor ratio. The calibrated G-factor can be well used to determine the ¹³C/¹²C of dissolved CO₂ in the hydrothermal experiments with ¹³C labelled. In-situ monitoring experiments show that the phase separation of the hydrothermal fluid hardly causes changes in the carbon isotope composition of dissolved CO₂. However, the contamination of organic matter, such as oxalic acid, will result in a higher content and a more negative δ¹³C of CO₂ in the hydrothermal fluids.

Critical minerals like copper, lithium, cobalt, nickel, and rare earth elements form the backbone of low-carbon technologies and are central to the success of global energy transitions. Their availability and the security of their supply chains determine the scalability of renewable energy systems, electric vehicles, battery storage, and hydrogen technologies. For member countries of the International Energy Agency (IEA), which plays a pivotal role in global energy markets, ensuring resilient access to these minerals is inseparable from the broader challenge of decoupling economic growth from carbon emissions. This study examines the dynamics of energy and carbon decomposition as mechanisms for decoupling economic growth from energy-related emissions across certain IEA countries between 1995 and 2022. The analysis employs a decomposition framework that incorporates value-added carbon intensity, value-added energy intensity, and CO₂ transport and storage while accounting for the enabling role of critical mineral availability. The results reveal that improvements in energy decomposition significantly strengthen the decoupling of growth from emissions, whereas increases in carbon decomposition weaken it. Similarly, higher value-added energy intensity is positively associated, and carbon intensity is negatively associated with decoupling, while expanded CO₂ transport and storage capacity tend to reduce its effectiveness. Notably, integrating into the analysis considerations related to mineral supply demonstrates that stable and diversified access to critical resources magnifies the benefits of energy decomposition while mitigating the risks that are linked to carbon intensity. These findings underscore the dual importance of policy frameworks that advance energy efficiency and decomposition and strategies that secure critical mineral supply chains to ensure clean technologies’ scalability.

Present models for the late Paleoproterozoic evolution of the Aravalli orogen (NW India) postulate the existence of a continental magmatic arc active between 1875 Ma and 1810 Ma, followed by a phase of post-collisional magmatism between 1730 Ma and 1700 Ma. However, the tectono-magmatic processes occurring between these two events remain cryptic. In this study, evidence for an intervening magmatic phase is revealed based on the investigation of granitoids exposed in the southern part of the Aravalli orogen. U-Pb zircon dating of these granitoids (granites to tonalites) yielded emplacement ages between 1770 Ma and 1760 Ma. Whole-rock geochemical data indicate a strongly peraluminous, S-type, high-K calc-alkaline character, with magnesian to ferroan signatures and a syn-collisional tectonic affinity. The REE patterns are predominantly highly fractionated, displaying depleted HREE profiles and moderate to weak negative Eu anomalies. The geochemical data further suggest derivation of the granitoids by partial melting of meta-greywackes at temperatures > 800 °C. Subchondritic eHf(t) values (−11.0 to −2.6) further indicate reworking of a heterogeneous crust. The results of this and previous studies collectively indicate that the Aravalli orogen evolved through three distinct late Paleoproterozoic tectono-magmatic phases: (1) subduction-related magmatism at 1875‒1810 Ma, (2) syn-collisional S-type plutonism at ca. 1770 Ma, and (3) post-collisional extension-related A-type magmatism at ca. 1720 Ma. Globally, Paleoproterozoic S-type granites were predominantly derived by anatexis of Archean crust. Additionally, the data suggest that the northern margin of proto-India collided with fragments of the Columbia supercontinent at ca. 1770 Ma, postdating Columbia’s maximum packing time (1900-1850 Ma).

Experimental studies have demonstrated that olivine can be wetted by sulfide liquid under specific conditions. In this study, we investigate elongated sulfide-olivine patches in lherzolite from the Dahuangshan mafic-ultramafic complex (Central Asian Orogenic Belt, NW China), which display textural evidence indicative of this phenomenon. Two-dimensional (2D) microbeam X-ray fluorescence (micro-XRF) mapping and three-dimensional (3D) high-resolution X-ray computed tomography (HRXCT) scanning reveal that the sulfide-olivine patches are 1.0 ‒ 4.8 cm long, 0.3 ‒ 2.3 cm wide and 0.2 ‒ 2.0 cm thick, and have sharp boundaries in the lherzolite matrix. These patches consist entirely of olivine (Fo_7-81.9) embedded within interstitial sulfides. The sulfides dominantly comprise pyrrhotite (>94 vol%), minor pentlandite (< 6 vol%) and trace chalcopyrite, and contain a total of 1.1 ‒ 1.9 wt.% (Ni + Cu + Co). Low olivine-olivine-sulfide dihedral angles (averaging 44.9 ° ) indicate that olivine was wetted by the sulfide liquid in these patches. The crystal size distributions (CSDs) of the olivine grains in the sulfide-olivine patches are different from those of the olivine in the lherzolite matrix. These observations can be explained by the entrainment of pre-existing sulfide-olivine cumulates into flowing magma. The elongated shape and parallel distribution of the sulfide-olivine patches indicate that the magma flow was laminar. These findings support the hypothesis that sulfide liquid can wet olivine and under the right conditions can be transported and deposited as sulfide-olivine aggregates within magma conduits.

Porphyry deposits are critical global sources of Cu, Mo, and Au. However, the mechanisms of post-mineralisation modification, exhumation, and preservation across different tectonic regimes remain poorly understood. The Mujicun deposit, a rare intracontinental porphyry Cu-Mo deposit in the North China Block, formed during the Early Cretaceous lithospheric thinning induced by the Paleo-Pacific slab rollback. Early studies focused predominantly on its genesis, the lack of research on post-mineralisation evolution has hindered regional prospecting. This study employs multiple geo-thermochronology, including zircon-apatite U-Pb and (U-Th)/He dating, as well as apatite fission-track analysis, combined with associated thermal history modelling, to elucidate the deposit’s temporal evolution, exhumation history, and preservation potential. Geochronological data indicate that dioritic magma emplacement and related Cu-Mo mineralisation at Mujicun occurred at ca. 146-141 Ma and ca. 145-138 Ma, respectively, coinciding with regional extension driven by Paleo-Pacific subduction. Integrated geo-thermochronological data and thermal history modelling reveal four tectono-thermal phases: (1) Late Cretaceous rapid cooling (ca. 110-95 Ma) and slow cooling during ca. 95-66 Ma, linked to lithospheric thinning of the eastern North China Block and the early uplift of the Taihang Mountains, triggered by Paleo-Pacific subduction and Okhotomorsk-Eurasia collision; (2) Late Cretaceous to Paleogene weak reheating (ca. 85-35 Ma), attributed to coeval sedimentary burial in the North Taihang Mountain and the nearby Bohai Basin; (3) Paleogene slow cooling (ca. 66-35 Ma), correlated with Pacific slab rollback and far-field effects from the India-Eurasia collision, inducing extensional uplift and exhumation of the Taihang Mountains; and (4) Neogene enhanced cooling (ca. 35-15 Ma), driven by Pacific subduction, India-Eurasia convergence, Tibetan Plateau extrusion, and the intensified East Asian monsoon, resulting in differential exhumation and planation of the Taihang Mountains. The Mujicun deposit shows exceptional preservation, as its total exhumation depth since ∼110 Ma (∼3.56 km) closely aligns with its original ore-forming depth (∼3.2-3.9 km). This indicates minimal post-mineralisation exhumation and limited erosional modification. Whereas current exploration targets shallow mineralisation (＜1.5 km), significantly deeper regional ore-forming depths (e.g., Dawan Mo deposit: 0.76–9.76 km) highlight the important potential for undiscovered Cu-Mo resources at depth within the North Taihang Mountain.

Carbonate clay-type lithium ore holds significant potential due to its extensive reserves, broad distribution, and relatively easy extraction. However, it presents significant beneficiation challenges due to its coexistence with karst-type bauxite, which often results in mixed, low-lithium ores. For the first time, spectral-texture features derived from hyperspectral imaging (HSI) are jointly modeled with a deep learning framework to explore the feasibility of pre-sorting carbonate clay-type lithium ores. Initially, the spectral responses reflecting mineral composition and the texture features characterizing structural differences were analyzed to evaluate the feasibility of using HSI for ore sorting. Furthermore, the influence of band selection, data standardization, and water absorption regions on pre-sorting performance was systematically investigated through comparative analysis of multiple dataset configurations. Two classification schemes, primary ore types classification and multi grade classification, were employed to assess sorting accuracy and identify key influencing factors. The proposed model, A ² ST-OSNet, achieves excellent results in both ore localization and classification through staged data input with varying dimensions and a modular design. Results revealed that joint modeling of spectral and texture features enables efficient and accurate pre-sorting, whereas models relying solely on either spectral or texture features were insufficient, as discriminative information for ore sorting is jointly determined by mineral composition and structural characteristics. Moreover, refined feature extraction and fusion strategies, including spectral-texture feature selection and attention mechanisms, proved critical in enhancing classification performance. The proposed approach offers valuable technical support for ore beneficiation and tailings reutilization, contributing to sustainable resource utilization and providing an effective solution for the efficient recycling of carbonate clay-type lithium ores.

Fluid distribution and migration characteristics hold significant importance in evaluating the quality of reservoir rocks. Two-dimensional nuclear magnetic resonance (2D NMR) measurements have been widely applied to identify specific hydrocarbon contents within rocks. However, due to the complexity of the pore and fluid system, this technique was not fully exploited and was limited by existing data processing methods. In this study, a novel centroid method was developed to enhance the quantification of 2D NMR data for fluids in reservoir rocks. This method calculates the centroid of the 2D NMR map, which correlates with the average pore size derived from the imbibition process. To validate its effectiveness, the method was applied to analyze the T₁ (longitudinal relaxation time) - T₂ (transverse relaxation time) relationships taken during imbibition processes in three different reservoir rocks. Results demonstrate that the position of centroid can be used to analyze the dominant type of water in pores involved in the imbibition process. Besides, this method can also successfully assess state changes for different water types inside samples by tracking centroids’ movements and fluctuations in centroid T₁/T₂ ratios, as well as utilizing the 2D NMR map’s signal partitioning capacity. Compared to other approaches, it elucidates the distribution and migration characteristics of water in different types of pores and provides significant advantages in the quantitative processing and comparative analyses of 2D NMR data across various water-bearing conditions. Furthermore, it also demonstrates significant potential for investigating interactions and dynamics of multiphase fluids in unconventional reservoirs.

Partition coefficients for Cl between felsic melts and a supercritical aqueous fluid ( ∼ 4-16 wt.% NaCl eq ) were experimentally determined to better constrain Cl behavior during magmatic fluid exsolution in upper-crustal magma chambers. Experiments were conducted at 850 ° C, 200 MPa, and oxygen fugacity near NNO + 0.5, using a range of melt and fluid compositions. At constant total chlorinity of 1 mol/kg H₂O, Dfluidmelt_Cl values range from 11.3 to 21.1, negatively correlated with both the melt’s aluminum saturation index (ASI) and the HCl/total Cl ratio in the fluid. For a fixed melt composition (ASI = 1.02), Dfluidmelt_Cl values increase linearly from 18.7 to 60.1 as total chlorinity rises from 1 to 4 mol/kg H₂O. Rayleigh fractionation modeling of fluid exsolution from upper-crustal magmas using these data indicates that during progressive crystallization, chlorinity of exsolved fluids rapidly decline before stabilizing at ∼ 1 mol/kg H₂O ( ∼ 4 wt.% NaCl eq ), regardless of initial fluid chlorinity or H₂O content in melt. This implies that the majority of exsolution fluids released from felsic magmas in the upper crust are of low salinity ( ∼ 1 mol/kg H₂O). Copper transfer modeling further suggests that efficient metal extraction occurs in Cl- and H₂O-rich magmas, particularly where early H₂O saturation is achieved, thus favoring the formation of high-grade porphyry copper deposits.

It is widely considered that porphyry Cu deposits formed via oceanic slab subduction are closely associated with hydrous and oxidized arc magmas. Of note, two suites of neighboring ( ∼ 40 km apart) Carboniferous arc volcanic rocks in Northwest China show different extents of mineralization: volcanic rocks from the Dananhu arc (DNHA) host one of the most important porphyry Cu deposit belts in China, whereas those from the Yamansu arc (YMSA), adjacent to DNHA, are ore-barren. These arc volcanic rocks, thus, provide a precious opportunity to explore the main factor that controls the genetic links between coeval arc lavas and porphyry Cu mineralization. Here we report whole rock major and trace element compositions and Mg-Sr-Nd-Pb isotopic data, generating a comprehensive geochemical comparison for these two suites of volcanic rocks from basalt to dacite. The whole-rock geochemical analyses suggest that at a given SiO₂ content, the YMSA basalts show lower MgO, CaO, Fe₂O₃^T, and TiO₂ contents than the DNHA basalts. The DNHA volcanic rocks have higher Sr/Y and (La/Yb)_N ratios, which are positively correlated, indicating that these two suites of rocks were derived from different magma sources. The DNHA rocks are characterized by radiogenic Pb isotopic compositions with ²⁰⁶Pb/²⁰⁴Pb up to 19.457, clearly distinct from the YMSA volcanic rocks with less radiogenic Pb isotopic compositions (²⁰⁶Pb/²⁰⁴Pb = 18.146-18.487), suggesting variable assimilation of crust-derived components during magma evolution. The δ²⁶Mg values of the DNHA rocks ( − 0.35 ‰ to +0.06 ‰ ) are largely similar to those of the YMSA rocks ( − 0.24 ‰ to +0.04 ‰ ), and both sets of isotopic ratio ranges have tendency toward heavy Mg isotopes, which could be attributed to serpentinite-derived high-δ²⁶Mg fluids in their mantle sources. Both suites of arc lavas have constant Cu contents and Cu/Sc ratios, indicating inconspicuous pre-enrichment of Cu contents. Geochemical comparisons indicate that the DNHA rocks were derived from partial melting of peridotite at the depth around the spinel-garnet transitional stability field, whereas the YMSA rocks were derived from partial melting of spinel peridotite, and the DNHA magmas had a thicker overlying plate than that of the YMSA magmas. The thickened arc lithosphere facilitates water-rich magmas accumulation and garnet fractionation, driving the magmas to become more oxidized, thereby preventing sulfide segregation and releasing sulfide-bound Cu. Thus, magmas differentiation in the thickened arc lithosphere is a key factor influencing porphyry Cu ore potential.

Recent discoveries of Late Mesozoic porphyry Cu deposits (PCDs) in Northeast (NE) China reveal a distinct spatial metallogenic zonation, with Late Jurassic PCDs in the north dominated by Cu-Mo and Early Cretaceous PCDs in the east marked by Cu-Au mineralization. However, the mechanisms controlling this metallogenic contrast remain unclear. To tackle this issue, we combined geological, geochronological, and geochemical data to determine the genesis of these deposits and the key factors controlling their distinct Cu-Mo and Cu-Au mineralization. Geochronological data show that the Late Jurassic PCDs were formed during a short-lived mineralization event (ca. 150-147 Ma), in contrast to the Early Cretaceous PCDs, which exhibit a prolonged formation history (ca. 120-95 Ma). Geochemical data demonstrate that the northern Cu-Mo PCDs originate from partial melting of thickened juvenile lower crust, whereas the eastern Cu-Au PCDs result from oceanic crust-derived melts contaminated by mantle wedge materials. Integrated analysis suggests that the Cu-Mo PCDs formed in a post-collisional setting after the Mongol-Okhotsk Ocean closure, while the Cu-Au PCDs formed in a subduction setting associated with Paleo-Pacific oceanic plate subduction. Despite the presence of hydrous and oxidized magmas in both regions, the northern PCDs exhibit higher Sr/Y, La/Yb, and Sm/Yb ratios than the eastern PCDs, indicating greater magma differentiation depths controlled by crustal thickness. We therefore propose that the depths of magma differentiation govern the metallogenic zoning of Late Mesozoic PCDs in NE China.

The main geological factors causing high levels of heavy metals (HMs) in soils in areas with sedimentary rocks are the exposure of black rock series (BRS) and the development of karst. The combined relationships, background concentrations, and speciation of Se and HMs in clastic rocks, carbonate rocks, and BRS remain unclear, which restricts HM traceability and remediation in high background soils. This study focuses on Ediacaran to Jurassic sedimentary rocks in South China and determines the total concentrations of Se, Cu, Zn, Pb, Hg, Cd, Cr, As, Ni, and total organic carbon (TOC), as well as their speciation. The results indicate that the TOC in sedimentary rocks is significantly positively correlated with Se, Hg, Cd, Cr, and Ni, followed by Cu and As, but not Pb and Zn. Cluster analysis reveals that Se is strongly associated with Cd and As. Compared with those in the upper continental crust (UCC), the enrichment levels of elements in BRS are ordered Se > Cd > Hg > As > Cr > Ni > Cu > Pb > Zn. The mean concentrations of Se, Cd, Hg, and As in BRS are 957.8, 62.9, 28.4, and 8.5 times those in the UCC, respectively. These elements are also relatively enriched in carbonate rocks. A risk assessment based on speciation indicates that Cd, Se and As in BRS have the greatest ecological risks, as well as Cd and As in carbonate rocks. Active speciation of Hg in all three rock types is less than 0.1% of the soil risk screening, indicating low risk. Therefore, the elevated risks of Cd, Se, and As in high-background areas may fundamentally stem from parent rocks. With a limited budget, the immediate focus should be on remediating Cd, As, and Se in the BRS areas, while also stepping up monitoring of Cd and As in the karst zones.

Surface water-groundwater (SW-GW) interactions at the basin scale are critical for effective water resource management but remain poorly constrained in Himalayan river systems. This study integrates hydrogeochemical (major and trace elements), isotopic (²H, ³H, ¹⁸O), and hydrogeological data to investigate water origin, residence time, hydrochemical evolution, and SW-GW connectivity in the transboundary Upper Jhelum River Basin (UJRB), western Himalayas. Hydrogeochemical facies analysis reveals that recharge waters (RW) and shallow groundwater (SGW) are dominated by Ca²⁺-Mg²⁺-HCO₃⁻ facies, while deep groundwater (DGW) evolves towards Ca²⁺-Na⁺-HCO₃⁻ facies, reflecting prolonged water-rock interaction. Seasonal variability highlights the influence of aquifer residence time and localized anthropogenic inputs on water chemistry. SW-GW interactions are evident in the transition from Ca²⁺-Mg²⁺-HCO₃⁻ in tributary waters to mixed facies in groundwater, indicating active recharge and subsequent mineral dissolution. Mixing model results (d¹⁸O and EC) show that groundwater is the dominant contributor to river baseflow, with contributions of 66 % ± 7 % in winter and 39 % ± 10 % in spring. River gaining conditions were identified along the alluvial and lacustrine plains, while localized losing stream conditions occurred near mountain front zones. Water-rock interactions, confirmed by Gibbs plots, govern basin hydrochemistry. Carbonate dissolution, gypsum dissolution, and silicate weathering are the primary processes, while Na-silicate weathering from the Panjal Traps shapes tributary chemistry. Ion exchange (Ca²⁺-Na⁺ and Mg²⁺-Na⁺ substitutions) further modifies groundwater composition along flow paths. Anthropogenic impacts, including wastewater infiltration and agricultural runoff, contribute to elevated Cl⁻, SO₄²⁻, and trace metal levels in specific zones. Evaporation effects are limited but elevate TDS locally. Glacier meltwater, characterized by Na⁺-Cl⁻-SO₄²⁻ facies, reflects atmospheric deposition and plays a minor hydrochemical role. These integrated findings underpin a conceptual flow model demonstrating how lithology, recharge dynamics, and anthropogenic pressures collectively shape SW-GW interactions. The results provide critical insights for managing transboundary Himalayan aquifers and sustaining river baseflows essential for regional water security.

Understanding how the multi-branches subduction of the Paleo-Tethyan Ocean controlled the intraplate tectono-sedimentary evolution of the South China Block (SCB) is fundamental to comprehending the mechanisms of ocean-continent transformation in cratonic basins and the formation of the Sichuan super-basin. This study investigated the Lower-Middle Permian successions (Liangshan, Chihsia, and Maokou formations) on the northwestern margin of the SCB, a critical area lies at the junction between the Songpan-Garzê and Qinling tectonic domains. These Permian successions are subdivided into four three-order sequences based on an isochronous stratigraphic framework that integrates various analyses of lithofacies, gamma-ray, stable isotopes, and zircon U-Pb ages. Lithofacies associations reveal that Lower-Middle Permian sequences record the sedimentary evolution process from shore-swamp environments to rimmed platforms. The paleogeomorphology pattern transitioned from a northwest lowland and southeast highland in the early Permian to a northeast lowland and southwest highland in the middle Permian, with corresponding development of linear high-energy grain shoals trending to northeast and northwest, respectively. These changes in lithofacies and paleogeography were attributed to the evolution of multiple branches of the Paleo-Tethyan, including the opening of the Garzê-Litang back-arc Ocean, along the western margin of the SCB in the Early Permian, followed by the rapid northward subduction of the Mianlue Ocean stretching along the northern margin of the SCB. Our findings demonstrate the regional cratonic tectono-sedimentary evolution coupled the multi-stage and multi-directional subduction of Paleo-Tethyan oceanic branches enhances our understanding of global deep-time multi-sphere interactions.

The Late Cretaceous magmatic evolution of northwestern (NW) Iran reveals a previously unrecognized continental arc system, the Azerbaijan Continental Magmatic Arc, herein termed the Azerbaijan Continental Magmatic Arc, which is largely obscured by subsequent tectonic overprinting, erosion, and basin burial. Integration of new zircon U-Pb ages, Lu-Hf isotopic data, and whole-rock geochemical compositions from volcanic and plutonic rocks in the Misho, Sufian, Moro, Amand, Vanyar, and Iskandar regions identifies a subduction-related arc system distinct from the Sanandaj-Sirjan and Urumieh-Dokhtar magmatic belts. The ∼ 101-97 Ma gabbros and granodiorites record e Hf ( t ) values from + 9.8 to − 7.2, reflecting variable mantle and crustal inputs. Arc-like trace-element patterns, including LREE enrichment and subduction-related anomalies, together with structural alignments along the Siah Cheshmeh-Khoy-Misho-Tabriz Fault (SKMT), indicate arc magmatism contemporaneous with transpressional deformation. The magmatic series evolved from juvenile tholeiitic to enriched shoshonitic compositions, tracking increasing crustal assimilation and slab rollback. This flare-up event represents a transient phase of Neo-Tethyan subduction, later overprinted by Eocene intrusions of the Urumieh-Dokhtar Magmatic Arc. Collectively, these results highlight the cryptic preservation of continental arcs and propose that the SKMT Fault marks a concealed suture accommodating Late Cretaceous arc migration and back-arc basin development in NW Iran.

Metal hydrides are essential materials with broad scientific and technological significance, showing unique properties in the fields of energy storage, catalysis, and superconductivity. Inspired by material science, we propose that natural hydrides can form in the Earth’s sedimentary basins due to existing favorable basis of matter and energy, which may provide a new perspective on understanding the geological origin and storage of natural hydrogen. In this study, we use a high-pressure gas reaction analyzer system to explore the hydrogenation reaction of typical transition metal powders (i.e., titanium (Ti), vanadium (V), chromium (Cr), and manganese (Mn)) under 50-200 °C and 3-5 MPa conditions relevant to sedimentary basins, and find that the hydrogenation reaction processes show apparent temperature dependence and can be efficiently promoted by pressure. Titanium exhibits a strong affinity for hydrogen, and its reaction with hydrogen is the largest among the four metals. The affinity of vanadium is second only to titanium. The affinity of chromium and manganese is at a similarly low level. As the temperature rises, the reaction quantity of titanium with hydrogen continues to increase; in contrast, the reaction quantity of vanadium and manganese with hydrogen shows a trend of first decreasing and then increasing; at 3 MPa, the reaction quantity of chromium with hydrogen shows a trend of first decreasing and then increasing, and at 5 MPa, the reaction quantity of chromium with hydrogen shows a trend of first increasing and then decreasing. After the in-situ hydrogenation experiments, combined XRD, ToF-SIMS, and NMR analysis on the quenched samples confirm the formation and stability of metal hydrides. Our study not only reveals the possibility of forming metal hydrides in sedimentary basins but also deepens our understanding of the metal-hydrogen interaction mechanism, providing a specific research basis for the formation of hydrides in shallow basins, which sheds light on the search for natural hydrides in sedimentary basins as a new energy source in the future.

The Crotone Basin (Calabria, Southern Italy) is a representative area in the Italian peninsula where Messinian halite deposits preserve three distinct crystal facies: (i) banded composed of cumulate halite and mud-rich interlayers, (ii) white consisting of bottom-growth crystals with chevron fabrics, and (iii) transparent made up of massive, optically pure crystals. The transparent facies appears to be undocumented in other Mediterranean Messinian basins, offering new perspective on halite crystallisation under variable environmental conditions. Microscopic observations (optical and scanning electron microscopy), supported by high-resolution 3D imaging through synchrotron-based X-ray microtomography, revealed a lack of pervasive recrystallisation in all facies, enabling the non-destructive visualisation of internal fabrics and inclusions. These methods provided critical insights into halite growth dynamics and the environmental conditions prevailing during deposition. Microthermometric data indicated that all halite crystals precipitated from a NaCl-MgCl₂-H₂O salt-water system under extreme evaporative conditions, with fluid salinity exceeding 340 ‰ - 360 ‰ and a distinct brine temperature for each facies ( ∼ 35 ° C in the banded, ∼ 45 ° C in the white, and ∼ 20 ° C in the transparent). Strontium isotope ratios (87Sr/86Sr) placed halite formation within the TG14-TG12 interval (ca. 5.61 - 5.55 Ma), with progressively increasing values from banded to transparent facies, suggesting enhanced continental input and brine dilution in the later stages of deposition. Organic matter was detected both in primary fluid inclusions and within the halite lattice, particularly in the white and transparent facies. Raman spectroscopy and UV-epifluorescence revealed amorphous organic compounds, including carotenoids and aliphatic functional groups such as methyl and methylene, which are commonly associated with microbial activity. These findings suggested that organic-rich brines may have played an active role in crystal nucleation and growth dynamics. The chemical immaturity and heterogeneous distribution of organic compounds imply a combination of autochthonous microbial input and episodic allochthonous influx, pointing to complex organic-mineral interactions during halite formation. The coexistence of three petrographically distinct halite facies within a confined area, each linked to specific environmental and geochemical conditions, supports the view that halite precipitation was modulated by fluctuations in hydrological balance, brine composition, and organic matter availability. These data contribute to a better understanding of the environmental and geochemical processes that controlled evaporite deposition during the Messinian Salinity Crisis.

Warming-driven acceleration of hydrological processes is altering the carbon cycle in permafrost-dominated Arctic regions, yet the underlying drivers remain unclear. This study analyzes ArcticGRO data (2003-2021) from six major Arctic rivers (Ob, Yenisei, Lena, Kolyma, Yukon, and Mackenzie) to investigate trends and spatial-temporal variations in riverine particulate organic carbon (POC). The annual POC flux from these six rivers, estimated using the Load Estimator (LOADEST), averaged 2.78 Tg. Only the Lena River showed a notable annual decrease in POC flux ( − 3.9%/yr, p < 0.001) and concentration ( − 12%/yr, p < 0.001), while the Yukon River exhibited increasing streamflow (+0.98%/yr, p < 0.001) and POC flux (+3.2%/yr, p < 0.001). POC flux variations were primarily governed by streamflow and POC concentration, with higher concentrations in spring floods period and lower during winter. Spatial differences were linked to drainage density ( Dd ) and forest coverage ( Fc ). The Yukon River basin, with a higher Dd of 0.2 km/km ² and lower Fc approximately 24%, exhibits the highest POC concentrations (2.3 mg/L). In contrast, the Yenisei River basin has the lowest POC concentration ( ∼ 0.4 mg/L), along with a relatively low drainage density ( Dd = 0.18 km/km ² ) and a high forest cover ( Fc = 67%). Permafrost conditions constrained riverine POC export, with isotopic evidence indicating a shift from a carbon sink to a source, as POC carbon age increased by ∼ 200 to 1700 years (4%-68%) annually, peaking in winter (700-2500 years) after 2012. Rivers with lower permafrost coverage (e.g., Ob, Yenisei), exhibit higher winter POC fluxes contributions (10%-20%), while others contributed < 5%, suggesting the role of permafrost degradation in winter carbon export. This study emphasizes the need to assess climate-driven hydrological shifts and permafrost thaw in shaping Arctic land-to-ocean carbon fluxes.

We present a new lithosphere-asthenosphere boundary (LAB) depth map of Iberia and adjacent areas built using 34500 Sp receiver functions from 998 broadband seismic stations, alongside an updated Ps-derived crustal thickness map of Iberia. We found an overall shallow LAB, with a minimum depth of 70-80 km in areas of Cenozoic extension such as the eastern coast of Iberia and the Gibraltar-Alboran subduction back-arc, as well as in the Massif Central and the tectonically stable northwest of Iberia. LAB depths from 90 km to 110 km were only found within the areas of thickened crust in north-central Iberia and bordering the Gulf of Cádiz. The much deeper (150-180 km) oceanic LAB of the Gibraltar-Alboran slab was also imaged in the western Gibraltar Arc. Sublithospheric negative-velocity gradients (NVG) in the 110-140 km depth range are widespread in the back-arc of the Gibraltar-Alboran subduction system and in north-central Iberia, picturing a layered asthenospheric structure. In the Gibraltar Arc, the detachment of the slab through the subduction-transform edge propagator fault in the eastern Betics seems linked to the formation of the NVG, which are limited to the north by this structure.

I have recently published ‘‘Do we really need to drill through the intact ocean crust?” in this journal (Geoscience Frontiors, 2025, Volume 16, 101954), which is a theme talk at the ‘‘ International Workshop on Fulfilling the Quest of Drilling Through the Ocean Crust Using D/V Meng Xiang (‘梦想号’)” held in Guangzhou (November 24 ‒ 27, 2024), and is an objective account of petrological properties of the ocea- nic Moho. The global geoscience community universally acknowledges that Moho is a seismic disconti- nuity representing the boundary between the crust ( V_P ≤ 7 km/s) and mantle ( V_P ≥ 8.0 km/s). However, the longstanding assumption of purely magmatic origin for the ocean crust has misled the sub- ject field. Evidence shows that the ocean crust formed at many slow-spreading ridge localities maintains a globally constant seismic thickness of ∼ 6 ± 1 km yet paradoxically comprises predominantly serpen- tinited mantle peridotite. This observation rationalizes the 60-year-old Hess-type Ocean crust hypothe- sis, while also underscoring the imperative for direct verification through intact ocean crust drilling − the core objective of the abandoned Project Mohole (1957 ‒ 1966). The workshop participants unanimously concurred that D/V Meng Xiang is currently the only operational platform capable of achieving intact ocean crust penetration. However, selection of optimal drilling sites needs further multidisciplinary dis- cussion for successful Moho penetration, allowing addressing the core question on the petrological nature of the oceanic Moho. Here, I suggest the following with justifications for consideration: (1) It is not pos- sible and thus has no significance to drill into the Moho on seafloors formed at slow- and ultraslow- spreading ridges; (2) it is feasible to succeed with well-prepared efforts in drilling through intact mag- matic crust at ideal sites of seafloors produced at the fast-spreading East Pacific Rise; (3) if the Pacific Moho is discovered to be serpentinization front, this will bring about a paradigm shift.

Flash floods cause substantial economic losses and casualties worldwide. Susceptibility-based flash flood mapping supports the development of effective flood mitigation strategies. While machine learning (ML) models offer superior accuracy, converting their outputs into spatially coherent and actionable maps remains challenging. Existing susceptibility maps often rely on subjective discretization and exhibit fragmented spatial patterns, limiting their utility in practice. In this context, this study proposes a novel framework that achieves the effective transformation of susceptibility prediction results into a management-oriented regionalization map. The framework integrates supervised learning, unsupervised clustering, and spatial explanatory feedback to enable information fusion and spatial restructuring of multi-model outputs. Flash flood susceptibility was first modelled using two supervised algorithms: Random Forest and CatBoost. Their outputs, along with exposed elements, were integrated and discretized using a two-stage clustering approach based on Self-Organizing Maps (SOM) and Ward’s method. Finally, a GeoDetector-based iterative optimization process was implemented to refine the regionalization by maximizing alignment with historical flash flood distributions. Results show that all susceptibility models achieved excellent predictive performance (AUC > 0.95), with the CatBoost model trained on grid-based samples performing best (AUC = 0.997). The final regionalization map exhibits regional contiguity and effectively captures historical flood patterns, explaining 73% of their spatial variability. The integration of hybrid ML with explanatory feedback provides a novel perspective for generating susceptibility regionalization maps that are both expressive of flash flood risk and spatially coherent, in addition to providing support for exploring region-specific defense measures.

The Yellow River provides an important foundation for the sustainable development of Chinese civilization. Compared with the upper part (dominated by the Tibetan Plateau) and the lower part (represented by the Yellow River Delta), the central part of the Yellow River Basin (encompassing most of the Loess Plateau) is the most arid and exhibits the most complex relationship between humans and nature. The Chinese government is continuously promoting the protection and management of the ecological environment in the central part of the Yellow River Basin, as it is related to the country’s food security and people’s health, biodiversity conservation and sustainable socio-economic development. However, the distribution patterns and evolution of key ecological elements in the region, which are important determinants of ecosystem productivity and health, have yet to be revealed. This study focused on three key ecological elements, namely, macronutrients (sediment organic carbon, SOC, total nitrogen, TN and total phosphorous, TP), heavy metals (Cu, Ni, Pb, Zn, Cr, Cd, Hg, and As) and microplastics, and aimed to systematically elucidate the change patterns of their concentrations and compositions in sediments from the mainstem of the Yellow River and neighboring typical lakes. The results revealed that the TN content was mostly greater than the SOC content in the sediments from the mainstem of the Yellow River. Moreover, the TN, SOC and heavy metal concentrations increased significantly as a result of agricultural cultivation. Among the six typical lakes, the highest concentrations of both macronutrients and heavy metals were observed in sediment samples from Mingcui Lake (MC; an urban wetland), followed by those in sediment samples from Wuliangsuhai Lake (WLS; surrounded by agricultural fields). Among the heavy metals, the concentrations of Zn and Cr were highest. The abundance of microplastics in the sediments from the mainstream of the Yellow River ranged from 233 to 3333 items kg^-1, while the abundance of microplastics in lake sediments ranged from 967 to 1556 items kg^-1. The other characteristics of microplastics were consistent, including the concentration of microplastic particles within the 0.2-2 mm range. The main colors of the sampled microplastics were blue, transparent, and gray-black. In addition, rayon accounted for the highest proportion among all polymer types, followed by PET and PE + PP. In general, the amount of the above three environmental elements is closely correlated with the intensity of human activities such as agriculture and urbanization. Stronger correlations were obtained between the concentrations of macronutrients and heavy metals. This study systematically reveals the change patterns of key ecological elements in the study area and advances the understanding of environmental changes, ecosystem evolution and sustainable development in the Yellow River Basin.