Using a combination of whole rock and stable isotope geochemistry, scanning electron and cathodoluminescence microscopy, micropaleontology, and microtexture analysis, the Upper Rhinestreet Event, the Lower Kellwasser Event (LKE), and the Upper Kellwasser Event (UKE) have been documented on the Indochina tectonic block from the Xom Nha Formation in Vietnam. This is the first detailed lithologic description of the Rhinestreet Event in Asia, as well as the first detailed lithologic description of the Lower and Upper Kellwasser Events on the Indochina tectonic block. The Rhinestreet Event is an anoxic horizon at ∼375 Ma that is not associated with an extinction horizon. The Late Devonian’s Frasnian-Famennian extinction (372 Ma) is associated with the ocean anoxia of UKE. The Kellwasser Events have been studied globally in successions that generally exhibit characteristic black shales and/or black limestones. However, the sedimentological record of the Xom Nha section in central Vietnam differs from other successions as it shows a continuous lithology of nearly pure limestone without black shales or bituminous limestone layers. We also report microfossils from the section, including phosphatized mazuelloids that likely represent planktonic acritarchs, organic filaments, and arthropod cuticle, although beds during and after the UKE are barren. These are the youngest known occurrences of mazuelloids. The whole rock geochemistry patterns combined with scanning electron microscopy microtextural observations indicate that anoxia and potentially a shutdown of the carbonate factory both occurred during the UKE and Upper Rhinestreet Event. In contrast, the LKE does not show anoxia but does exhibit increased productivity. These contrasting signatures are consistent with other studies of the UKE/LKE globally and indicate that they had differing causes. We conclude that the UKE and LKE should be considered distinct events despite their temporal proximity and common nomenclature
Methane (CH4) is a potent short-lived climate pollutant with a warming potential significantly greater than carbon dioxide over a 20-year timeframe. While its reduction is critical for climate mitigation, its broader implications for the Sustainable Development Goals (SDGs) remain underexplored. This study provides the first comprehensive global assessment of the linkages between CH4 emission trends and all 17 SDGs. Employing a quasi-experimental Difference-in-Differences (DID) design, we analyze panel data from 196 countries (2000–2020) and leverage the submission of Nationally Determined Contributions (NDCs) as a proxy for national mitigation commitments. Our results reveal robust associations between CH4 mitigation commitments and accelerated progress across multiple SDGs. A synergistic relationship exists where CH4 reduction is positively linked to the majority of SDGs, directly or indirectly relating to 51 out of 169 specific targets. Pathways are multifaceted: technological innovation and energy structure adjustment are key drivers for progress in SDG7 (Energy), SDG9 (Industry), and SDG13 (Climate Action). The positive associations are substantially stronger for low- and middle-income countries, particularly for SDG5 (Gender Equality), SDG9, and SDG13. Our findings highlight the significant potential for aligning climate action with the 2030 Agenda and provide evidence-based insights for integrated policy planning, especially for developing regions. We clarify that the identified linkages represent policy-relevant associations derived from a robust quasi-experimental design, not definitive causal estimates.
The arc-continent suture zone separating the Neoproterozoic Arabian-Nubian shield from Archean-Paleoproterozoic crust of the Saharan meta-craton has long been thought to coincide with the Keraf structural corridor. This interpretation remains debated, and it is unclear whether crustal blocks on either side of the hypothesised suture have distinct geological histories. In this study, we integrate field observations, whole-rock geochemistry, zircon U-Pb-Hf and whole-rock Sr-Nd isotopic data from plutons sampled along an ∼ 80 km-long transect across the central Keraf domain and propose that it represents a structurally modified, juvenile intra-oceanic arc terrane formed between ca. 840–655 Ma.Pre- to syn-tectonic intrusions define a two-stage intra-oceanic arc history: (i) juvenile, mantle-derived arc magmatism between ca. 840–810 Ma (εHf(i) ∼ +9.1 to + 10.7, εNd(i) ∼ +3.8 to + 4.7), and (ii) protracted arc thickening by magmatic accretion between ca. 760–655 Ma (εHf(i) ∼ +7.7 to + 9.0, εNd(i) ∼ +3.7 to + 6.2), with contribution from early arc crust material. The apparent absence of zircon crystallisation ages between ca. 810–760 Ma may reflect trenchward arc migration, although alternative processes cannot yet be excluded, and the significance of this pattern remains unclear. Post-collisional granites at ca. 620 Ma (εHf(i) ∼ +8.2 to + 8.8; εNd(i) ∼ +3.3 to + 4.6) likely record reworking of the Keraf arc crust, with limited, if any, enriched-mantle input during the late to post-collisional period.Integration of our results with regional isotopic compilations shows that the isotopically more evolved Bayudian (ca. 970–890 Ma) and syn-Keraf arc magmatic events affected the pre-Neoproterozoic basement in the easternmost Saharan meta-craton. Although this hypothesis remains to be demonstrated, the available data are consistent with a scenario involving subduction transference from the Bayuda continental arc to the Keraf intra-oceanic arc at ca. 890–860 Ma, implying that the Arabian-Nubian shield–Saharan meta-craton suture zone may lie farther west than currently accepted.
Extrapolating the modern lunar recession rate into deep time is incompatible with the Moon’s ∼ 4.5-billion-year age, implying time-variable Earth–Moon tidal evolution. Existing models invoke different mechanisms for this variability, but remain insufficiently tested by continuous geological constraints. Here we compile 60 cyclostratigraphic records spanning 2,465–68 Ma, uniformly reprocess them with TimeOptB, synthesize Earth’s axial precession frequency estimates using Locally Adaptive Gaussian Process Regression, and convert them into probabilistic length-of-day and a corresponding tidal-dissipation trajectory. We find that relative tidal dissipation was generally reduced during intervals of supercontinent stability, but became higher and more variable during breakup–reorganization intervals. These results support a testable link between supercontinent-paced ocean-basin reorganization and long-term variations in oceanic tidal dissipation.
The Central Asian Orogenic Belt (CAOB) preserves the complete evolution of the Paleo-Asian Ocean (PAO). The Changchun–Yanji Suture Zone, the easternmost PAO suture between the North China Craton (NCC) and the Zhangguangcai continental arc–Jiamusi–Khanka Block (ZJKB), records the final closure of the PAO, but its timing, position and mechanism remain debated. We integrate structural analysis of ductile shear zones with zircon U–Pb geochronology to constrain the PAO closure processes in NE China. Two NW–SE-trending ductile shear zones, the Jiapigou and Gudonghe ductile shear zones, record thrust-related deformation with opposite directions across the Yalu River Fault (YRF), characterized by SW-directed thrusting to the west of the YRF and NE-directed thrusting to the east. Zircon U–Pb ages constrain this deformation to the Late Triassic, ca. 229–220 Ma. Structural correlations with high-strain belts, the εHf(t) spatial distribution, and biogeographic boundaries delineate the eastern PAO suture along Kaiyuan–Shancheng–Huadian–Liangjiang–Xiaohuanggou–Baijin. We interpret the YRF originally as a lithosphere-scale transform fault. Before the final closure, the PAO underwent ridge-involved bidirectional subduction on both sides of the YRF. During closure, the ridge segment on the west of the YRF was subducted southward beneath the NCC while the remaining slab continued northward subduction, whereas on the east of the YRF, the ridge segment was subducted northward beneath the ZJKB and the remaining slab continued southward subduction. In the final closure stage, the transform fault (future YRF) cut into both continental margins, resulting in oppositely directed thrusting on both sides of the YRF. This deformation records the collisional orogenic stage associated with the final closure of the PAO. Subsequent Paleo-Pacific subduction may have reactivated the inherited Yalu River Fault and adjacent shear zones, further modifying the earlier PAO-related structures.
The adsorption of ecomolecules onto micro- and nanoplastic (MNP) surfaces in aquatic environments forms an eco-corona that reshapes MNP environmental fate and biological effects. This review provides a comprehensive overview of the dynamic interaction mechanisms between MNPs and major corona constituents, with an emphasis on polymer specificity and preferential binding hierarchies. We discuss how these interfacial mechanisms govern the environmental fate of eco-corona coated MNPs, particularly with respect to aggregation and deposition. We examine the multistage process by which eco-corona coated MNPs interact with aquatic organisms, evaluating their roles in organismal uptake, intestinal injury, and intracellular transport. In addition, we introduce the concepts of primary corona and secondary corona to distinguish the environmentally acquired corona formed before biological exposure from the corona restructured after contact with biological surfaces or internal microenvironments. We synthesize these observations into a time-resolved framework in which rapid initial adsorption is followed by competitive molecular exchange, hard/soft corona development, MP-derived DOM release and incorporation, corona restructuring, and, after biological exposure, secondary corona formation. Finally, we underscore the need for environmentally realistic exposure designs and time-resolved, interface-resolved characterization, and advocate moving the field from static adsorption-based descriptions towards a dynamic, multistage eco-corona framework to address the environmental fate and risk assessment of MNPs in aquatic systems.
In low-latitude alpine regions, intense local evaporation and transpiration significantly influence precipitation patterns, though the underlying mechanisms remain poorly understood. This study investigates the rainy season water cycle and its formation mechanisms in the Mount Cangshan using stable isotope data (from precipitation, fog water, and surface water) and meteorological records collected at various elevations in 2023. The results demonstrate an anti-altitude effect in precipitation stable isotopes across low-latitude alpine regions. Specifically, on the western slopes (the windward side of the southwest monsoon), δ18O in precipitation exhibits an anti-altitude effect for two months, while on the eastern slopes, this effect persisted for four months at different elevations. This reflects terrain-driven valley winds transporting low-level locally recycled moisture upslope to condense, producing an anti-altitude effect across different slopes and elevations. As the leeward slope, the eastern flank relies predominantly on locally recycled moisture (over 50 % pre- and during weak monsoons), with its dry, hot climate further enhancing surface and lake evaporation. During peak monsoon, vapor from Erhai Lake contributes over 30 % of the recycled moisture at the eastern foot, serving as a key source sustaining its high precipitation. Additionally, advected water vapor transport is not a simple source shift, but a dynamic process governed by transport height, rainout along trajectories, and multi-source mixing. This process determines the seasonal isotopic variability of the advected vapor and, in combination with local moisture recycling, jointly shapes the complex spatial distribution of precipitation isotopes in the alpine region. This study improves understanding of local climate and water vapor cycling, supporting early warning, water management, and sustainable development in alpine regions.
This study investigates the determinants of environmental sustainability in France by examining the effects of eco-innovation, energy taxation, renewable energy consumption, economic growth, natural resources, and manufacturing activity on the load capacity factor over the period 1980–2023. Unlike conventional environmental indicators that focus primarily on carbon emissions, the load capacity factor captures the balance between ecological demand and ecological supply, providing a broader measure of ecological sustainability. The study employs a comprehensive empirical framework including robust and Newey–West regressions, autoregressive distributed lag models, nonlinear asymmetry analysis, quantile regression, rolling-window estimation, and policy-regime analysis associated with the Kyoto and Paris climate agreements. The findings reveal that renewable energy consumption and energy taxation improve environmental sustainability, while economic growth, natural resources, and manufacturing activity exert negative ecological effects. Eco-innovation exhibits nonlinear dynamics, suggesting that technological transition initially involves adjustment costs before stronger environmental gains emerge over time. The results further indicate that the Paris climate-policy regime strengthened the positive contribution of green-transition variables to environmental sustainability. Quantile regression findings reveal substantial heterogeneity across sustainability conditions, implying that environmental-policy effectiveness varies across ecological-performance levels. Diagnostic and robustness analyses confirm the stability of the main findings despite the presence of strong macroeconomic interrelationships. The study concludes that long-run environmental sustainability in France depends on the interaction between renewable-energy transition, climate-policy intensity, technological transformation, and structural economic adjustment. The findings provide important policy implications for strengthening green fiscal reforms, renewable-energy investment, sustainable industrial transformation, and innovation-oriented environmental governance.
The variations in mantle sources beneath mid-ocean ridges play a crucial role in shaping the geochemical characteristics and accretion processes of oceanic crust. In this study, we present an integrated petrological, geochronological, and geochemical investigation of an ancient oceanic lithosphere segment represented by the North Renco ophiolitic complex in the southernmost portion of the Bangong-Nujiang suture zone, central Tibetan Plateau. The complex includes a fragmented mafic association that is divided into three distinct units: intra-plate oceanic island remnants, and V1- and V2-type oceanic crustal units. Zircon U-Pb dating results indicate that the intra-plate ocean island remnants and the V1 unit formed during the Middle Jurassic (ca. 170–165 Ma), while the V2 unit formed some 15 million years later in the Late Jurassic (ca. 150 Ma). The intra-plate remnants exhibit a characteristic basalt-limestone interlayered structure, and the basalts display geochemical features typical of ocean island basalts (OIB), indicative of derivation from a deep, high-temperature, and enriched mantle source. The V1 unit mainly comprises large-scale sheeted dikes with enriched mid-ocean ridge basalt (E-MORB) geochemical signatures. Their elemental and isotopic compositions define an evolutionary trend from mid-ocean ridge basalt (MORB) to OIB affinities, indicating derivation from a depleted asthenospheric mantle source that was metasomatized by deeply derived plume-like mantle source. In contrast, the V2 unit consists of a relatively continuous sequence of middle to upper oceanic crust, characterized by normal mid-ocean ridge basalt (N-MORB) geochemical features and highly depleted Nd-Hf isotopic compositions. This indicates that it originated from 10 to 20% decompression partial melting of a depleted spinel lherzolite mantle. Thus, the North Renco ophiolitic complex disparate mafic assemblages formed through the tectonic superposition of rocks from different ages and genetic mechanisms, recording two stages of oceanic crust accretion in the Meso-Tethys Ocean
This paper integrates economic performance, energy security, and environment-related indicators into a unified performance evaluation framework. The findings reveal significant regional disparities and individual heterogeneity in energy security performance across China’s provinces. Provinces with lower energy security performance are predominantly concentrated in the central and western regions, while those with higher performance are mainly distributed in the eastern and southern coastal areas, as well as the northwestern and northeastern regions.The results based on the Method of Moments Quantile Regression (MMQR) indicate that the proportion of fossil energy consumption exerts a negative impact on energy security performance from the 10th to the 70th quantiles, with this adverse effect exhibiting an increasing trend across quantiles. Therefore, an increase in the share of renewable energy consumption generally enhances energy security performance, particularly in regions with higher performance levels.The proportion of renewable energy generation shows a significantly positive effect in the 10th–40th quantile range but a negative effect in the 50th–90th percentile range, with statistical significance at the 90th quantile. Thus, the relationship between renewable energy share and energy security performance is notably asymmetric and nonlinear. Promoting renewable energy generation yields greater benefits for low-performance regions, whereas it may adversely affect high-performance regions. Furthermore, panel Granger causality tests confirm that renewable energy development predictably influences energy security performance, but not vice versa.
The timing of North Falkland Basin (NFB) rifting, and how the wider Falkland Plateau fits into the history of the breakup of Southern Gondwana, has been a topic of debate and uncertainty. This has been exacerbated by a complete lack of direct geochronological age constraint on the sedimentary fill of the Early Syn-rift in the NFB. This study presents an analysis of well data, core from the Early Syn-rift interval, seismic interpretation, and new zircon U-Pb age dating. The resulting depositional model supports a revised understanding of the sedimentary environment and structural setting of the syn-rift of the NFB. The Early Syn-Rift strata infill a series of NW–SE striking sub-basins, which together comprise the Southern North Falkland Basin (SNFB). The overstepping Late Syn-rift rests unconformably above the lower syn-rift sequence, and is accommodated by a series of syn-depositional N–S trending fault-bounded basins that together form the Central North Falkland Basin (CNFB). The NFB Early Syn-Rift is characterised by ephemeral fluvial–fluvio-lacustrine and volcaniclastic intervals, with nine identified sedimentary facies assigned to five distinct facies associations. An analysis of ashfall tuffs identified in core from the 14/24––1 well yields a new LA-ICP-MS zircon U-Pb age determination of 175 ± 5Ma (early to middle Jurassic) for the upper part of the Early Syn-rift. These results provide the first absolute age determination for Early Syn-rift strata in the NFB, and implies that they are substantially older than previous models suggest (by between 13.9–41 Ma). This suggests that the NW–SE striking basins of the SNFB developed as a result of Gondwana rifting during the early to middle Jurassic. The findings provide clear evidence for two distinct syn-rift packages in the NFB, with early to middle Jurassic (Gondwana) depocentres and associated faults overprinted by later N–S trending early Cretaceous sub-basins.
Glaciers in the Western Himalayas are experiencing sustained mass loss and dynamic changes under a warming climate; however, integrated assessments of glacier mass balance and surface ice velocity remain limited. The Upper Tons Basin (UTB), a debris-dominated and hydrologically important basin, has so far lacked any glacier-wide geodetic mass-balance assessment. Here, we present the first mass-balance estimates for UTB glaciers and update regional records by combining geodetic mass-balance and multi-temporal analyses of surface ice velocity for 59 glaciers (≥1 km2) in the Upper Tons and Baspa basins from 2000 to 2024. Glacier elevation change was estimated from differencing the SRTM v3 DEM (2000) and ASTER-derived DEM (2024) generated using the Ames Stereo Pipeline. Glacier surface velocities for 2000–2001, 2005–2006, 2013–2014, 2015–2016, and 2023–2024 were derived from Landsat ETM + and OLI panchromatic imagery using the COSI-Corr method. Climatic trends were assessed using ERA5– Land and MERRA-2 reanalysis data, and the role of non-climatic factors was evaluated. Results indicate widespread glacier thinning, with a mean cumulative mass balance of −11.45 ± 3.72 m water equivalent (m w.e.) and a mean annual rate of −0.48 ± 0.11 m w.e. a⁻1. Median glacier surface velocities increased from 18.75 m a⁻1 in 2000–2001 to 32.43 m a⁻1 in 2005–2006, followed by a marked decline to 6.88 m a⁻1 in 2013–2014. Subsequently, glacier velocities exhibited a partial recovery, increasing to 10.91 m a⁻1 in 2015–2016 and 12.62 m a⁻1 in 2023–2024. Basin-wise contrasts reveal less negative mass balance but persistently sluggish flow in the debris-dominated UTB, while Baspa Basin glaciers show higher velocities and more negative mass balance. This integrated assessment extends regional glacier records into the present decade and emphasizes the importance of jointly evaluating glacier mass balance and ice dynamics in debris-dominated Himalayan basins.
This study presents a comprehensive assessment of wind and solar variability across 1,000 real sites in North America and Europe, using 10 years of high-resolution meteorological data. A unified methodological framework was developed to harmonize datasets, convert meteorological variables to electrical output, and quantify variability across short-term, diurnal, seasonal, and interannual time scales. Results from the analyzed 2013–2022 period show that wind generation exhibits substantially higher short-term volatility and a greater frequency of extreme ramp events, whereas solar generation demonstrates comparatively smoother short-term behavior, regular diurnal cycles, and larger seasonal amplitudes, particularly at higher latitudes. Interannual analysis reveals strong year-to-year variability in wind resources and comparatively stable solar output. Extreme-event characterization indicates that wind droughts tend to be longer and more spatially extensive, while solar droughts are shorter but more frequent. Spatial correlation patterns and clustering analyses highlight distinct renewable regimes shaped by regional climate dynamics. These insights support improved planning for flexibility, storage, and cross-regional balancing in high-renewable energy systems.
Computational biostratigraphic techniques have enhanced the resolving power attainable by chronostratigraphic time scales, and enable the explicit quantification of uncertainty inherent in establishing biostratigraphic correlations. This study employs the quantitative biostratigraphic model Horizon Annealing to assemble a composite palynostratigraphic time scale in the late Carboniferous-Permian succession of the intracratonic Canning Basin (Western Australia). The data at hand consist of 9,719 individual occurrences of 92 pollen-spore taxa in 542 subsurface assemblages from 56 holes across the basin. Horizon Annealing employs a simulated annealing procedure to place the first and last appearance datums of all palynological taxa in temporal sequence and, by extension, all palynological assemblages at hand. The total solution space consists of all possible orderings of assemblages that do not violate the internal stratigraphy of any section. Because multiple similarly-optimal solutions exist in the vast solution space, the palynological composite considers the distribution of events (first and last appearance datums and dated positions) across 31 independent solutions to the sequencing task. Calibration of the composite sequence relies on geochronologic dates situated in the same stratigraphic sections as the palynological assemblages, as well as two biostratigraphic datums elsewhere linked to absolute time. The analysis couples explicit measures of sequencing and calibration uncertainty to develop a comprehensive record of palynological change in late Paleozoic sediments of the Canning Basin, and illustrates a methodological pipeline for assembling similar biostratigraphic schema in other deep time contexts.
