The 2024 Geoscience Frontiers Annual Convention was held in Kuching,Malaysia,from November 18th to 22th,2024,jointly with the 2024 IAGR Annual Convention and the 21st International Conference on Gondwana to Asia.The I...The 2024 Geoscience Frontiers Annual Convention was held in Kuching,Malaysia,from November 18th to 22th,2024,jointly with the 2024 IAGR Annual Convention and the 21st International Conference on Gondwana to Asia.The IAGR Convention attracted over 150 participants from various countries,including China,India,Australia,the Republic of Korea,Japan,Malaysia,Indonesia,Thailand,Italy,Mexico,the United Kingdom,Saudi Arabia,France,and Brunei.展开更多
1AIM AND SCOPE Geoscience Frontiers(GSF)publishes peer reviewed research articles and reviews in interdisciplinary fields of Earth and Planetary Sciences.GSF bridges innovative,provocative and challenging concepts and...1AIM AND SCOPE Geoscience Frontiers(GSF)publishes peer reviewed research articles and reviews in interdisciplinary fields of Earth and Planetary Sciences.GSF bridges innovative,provocative and challenging concepts and models related to various fields of research including petrology and geochemistry in understanding lithospheric architecture and mantle dynamics,global tectonics,economic geology and fuel exploration,geophysics,stratigraphy and paleontology with insights on correlations and evolution,environmental and engineering geology,astrogeology,nexus of resources-energy-emissions-climate under Sustainable Development Goals,among other themes.展开更多
1AIMANDSCOPE Geoscience Frontiers(GSF)publishes peer reviewed research articles and reviews in interdisciplinary fields of Earth and Planetary Sciences.GSF bridges innovative,provocative and challenging concepts and m...1AIMANDSCOPE Geoscience Frontiers(GSF)publishes peer reviewed research articles and reviews in interdisciplinary fields of Earth and Planetary Sciences.GSF bridges innovative,provocative and challenging concepts and models related to various fields of research including petrology and geochemistry in understanding lithospheric architecture and mantle dynamics,global tectonics,economic geology and fuel exploration,geophysics,stratigraphy and paleontology with insights on correlations and evolution,environmental and engineering geology,astrogeology,nexus of resources-energy-emissions-climate under Sustainable Development Goals,among other themes.展开更多
1AIM AND SCOPE Geoscience Frontiers(GSF)publishes peer reviewed research articles and reviews in interdisciplinary fields of Earth and Planetary Sciences.
The contributions of our referees remain vital to maintaining the high quality of papers published in Geoscience Frontiers.Their thoughtful critiques,dedication to reviewing,and,on occasion,re-reviewing manuscripts su...The contributions of our referees remain vital to maintaining the high quality of papers published in Geoscience Frontiers.Their thoughtful critiques,dedication to reviewing,and,on occasion,re-reviewing manuscripts submitted to the journal are deeply appreciated by boththe Editors and the Publisher.We would like to take this opportunity to extend our heartfelt thanks to the following referees for theirinvaluable input and support in reviewing manuscripts submitted in 2024.展开更多
Hurricanes are one of the most destructive natural disasters that can cause catastrophic losses to both communities and infrastructure.Assessment of hurricane risk furnishes a spatial depiction of the interplay among ...Hurricanes are one of the most destructive natural disasters that can cause catastrophic losses to both communities and infrastructure.Assessment of hurricane risk furnishes a spatial depiction of the interplay among hazard,vulnerability,exposure,and mitigation capacity,crucial for understanding and managing the risks hurricanes pose to communities.These assessments aid in gauging the efficacy of existing hurricane mitigation strategies and gauging their resilience across diverse climate change scenarios.A systematic review was conducted,encompassing 94 articles,to scrutinize the structure,data inputs,assumptions,methodologies,perils modelled,and key predictors of hurricane risk.This review identified key research gaps essential for enhancing future risk assessments.The complex interaction between hurricane perils may be disastrous and underestimated in the majority of risk assessments which focus on a single peril,commonly storm surge and flood,resulting in inadequacies in disaster resilience planning.Most risk assessments were based on hurricane frequency rather than hurricane damage,which is more insightful for policymakers.Furthermore,considering secondary indirect impacts stemming from hurricanes,including real estate market and business interruption,could enrich economic impact assessments.Hurricane mitigation measures were the most under-utilised category of predictors leveraged in only 5%of studies.The top six predictive factors for hurricane risk were land use,slope,precipitation,elevation,population density,and soil texture/drainage.Another notable research gap identified was the potential of machine learning techniques in risk assessments,offering advantages over traditional MCDM and numerical models due to their ability to capture complex nonlinear relationships and adaptability to different study regions.Existing machine learning based risk assessments leverage random forest models(42%of studies)followed by neural network models(19%of studies),with further research required to investigate diverse machine learning algorithms such as ensemble models.A further research gap is model validation,in particular assessing transferability to a new study region.Additionally,harnessing simulated data and refining projections related to demographic and built environment dynamics can bolster the sophistication of climate change scenario assessments.By addressing these research gaps,hurricane risk assessments can furnish invaluable insights for national policymakers,facilitating the development of robust hurricane mitigation strategies and the construction of hurricane-resilient communities.To the authors’knowledge,this represents the first literature review specifically dedicated to quantitative hurricane risk assessments,encompassing a comparison of Multi-criteria Decision Making(MCDM),numerical models,and machine learning models.Ultimately,advancements in hurricane risk assessments and modelling stand poised to mitigate potential losses to communities and infrastructure both in the immediate and long-term future.展开更多
Energy poverty in developing countries is a critical issue characterized by the lack of access to modern energy services,such as electricity and clean cooking facilities,as marked in SDG 7.This study explores the corr...Energy poverty in developing countries is a critical issue characterized by the lack of access to modern energy services,such as electricity and clean cooking facilities,as marked in SDG 7.This study explores the correlations between energy poverty,energy intensity,resource abundance,and income inequality,as these factors have been theorized to play important roles in influencing energy poverty in developing countries.By observing that the dataset is heterogeneous across the countries and over the time frame,we use the Method of Moments Quantile Regression(MMQR)to analyze our developing countries’data from 2000 to 2019.Our findings indicate that energy intensity is a significant factor influencing energy poverty,suggesting that higher energy consumption relative to the sample countries can exacerbate this issue.Additionally,we observe that income inequality within the sample countries is a critical determinant of energy poverty levels,highlighting the dynamics between economic disparity and access to energy resources.Interestingly,our study reveals that resource abundance acts as a blessing rather than a curse in terms of energy poverty,implying that countries rich in natural resources may have better opportunities to combat energy deprivation.Finally,we emphasize the vital role of financial markets in addressing energy poverty on a global scale,suggesting that robust financial systems can facilitate investments and innovations aimed at improving energy access for vulnerable populations.The results from the robustness analysis support the empirical results obtained from the main estimation.The empirical findings of the present study advance important comprehensions for policymakers to adopt energy policies that address the complex challenges of energy poverty and promote inclusive energy access.展开更多
The investigations of physical attributes of oceans,including parameters such as heat flow and bathymetry,have garnered substantial attention and are particularly valuable for examining Earth’s thermal structures and...The investigations of physical attributes of oceans,including parameters such as heat flow and bathymetry,have garnered substantial attention and are particularly valuable for examining Earth’s thermal structures and dynamic processes.Nevertheless,classical plate cooling models exhibit disparities when predicting observed heat flow and seafloor depth for extremely young and old lithospheres.Furthermore,a comprehensive analysis of global heat flow predictions and regional ocean heat flow or bathymetry data with physical models has been lacking.In this study,we employed power-law models derived from the singularity theory of fractal density to meticulously fit the latest ocean heat flow and bathymetry.Notably,power-law models offer distinct advantages over traditional plate cooling models,showcasing robust self-similarity,scale invariance,or scaling properties,and providing a better fit to observed data.The outcomes of our singularity analysis concerning heat flow and bathymetry across diverse oceanic regions exhibit a degree of consistency with the global ocean spreading rate model.In addition,we applied the similarity method to predict a higher resolution(0.1°×0.1°)global heat flow map based on the most recent heat flow data and geological/geophysical observables refined through linear correlation analysis.Regions displaying significant disparities between predicted and observed heat flow are closely linked to hydrothermal vent fields and active structures.Finally,combining the actual bathymetry and predicted heat flow with the power-law models allows for the quantitative and comprehensive detection of anomalous regions of ocean subsidence and heat flow,which deviate from traditional plate cooling models.The anomalous regions of subsidence and heat flow show different degrees of anisotropy,providing new ideas and clues for further analysis of ocean topography or hydrothermal circulation of mid-ocean ridges.展开更多
The application of machine learning for pyrite discrimination establishes a robust foundation for constructing the ore-forming history of multi-stage deposits;however,published models face challenges related to limite...The application of machine learning for pyrite discrimination establishes a robust foundation for constructing the ore-forming history of multi-stage deposits;however,published models face challenges related to limited,imbalanced datasets and oversampling.In this study,the dataset was expanded to approximately 500 samples for each type,including 508 sedimentary,573 orogenic gold,548 sedimentary exhalative(SEDEX)deposits,and 364 volcanogenic massive sulfides(VMS)pyrites,utilizing random forest(RF)and support vector machine(SVM)methodologies to enhance the reliability of the classifier models.The RF classifier achieved an overall accuracy of 99.8%,and the SVM classifier attained an overall accuracy of 100%.The model was evaluated by a five-fold cross-validation approach with 93.8%accuracy for the RF and 94.9%for the SVM classifier.These results demonstrate the strong feasibility of pyrite classification,supported by a relatively large,balanced dataset and high accuracy rates.The classifier was employed to reveal the genesis of the controversial Keketale Pb-Zn deposit in NW China,which has been inconclusive among SEDEX,VMS,or a SEDEX-VMS transition.Petrographic investigations indicated that the deposit comprises early fine-grained layered pyrite(Py1)and late recrystallized pyrite(Py2).The majority voting classified Py1 as the VMS type,with an accuracy of RF and SVM being 72.2%and 75%,respectively,and confirmed Py2 as an orogenic type with 74.3% and 77.1%accuracy,respectively.The new findings indicated that the Keketale deposit originated from a submarine VMS mineralization system,followed by late orogenic-type overprinting of metamorphism and deformation,which is consistent with the geological and geochemical observations.This study further emphasizes the advantages of Machine learning(ML)methods in accurately and directly discriminating the deposit types and reconstructing the formation history of multi-stage deposits.展开更多
How the subduction direction of the Paleo-Pacific plate beneath the Eurasian plate changes in the Early Cretaceous remains highly controversial due to the disappearance of the subducted oceanic plate.Intraplate deform...How the subduction direction of the Paleo-Pacific plate beneath the Eurasian plate changes in the Early Cretaceous remains highly controversial due to the disappearance of the subducted oceanic plate.Intraplate deformation structures in the east Asian continent,however,provide excellent opportunities for reconstructing paleostress fields in continental interior in relation to the Paleo-Pacific/Eurasian plate interaction.Anisotropy of magnetic susceptibility(AMS),geological,and geochronological analyses of post-kinematic mafic dykes intruding the detachment fault zone of the Wulian metamorphic core complex(WL MCC)in Jiaodong Peninsula exemplify emplacement of mantle-sourced dykes in a WNW-ESE(301°-121°)oriented tectonic extensional setting at ca.120 Ma.In combination with the results from our previous kinematic analysis of the MCC,a ca.21°clockwise change in the direction of intraplate extension is obtained for early(135-122 Ma)extensional exhumation of the MCC to late(122-108 Ma)emplacement of the dykes.Such a change is suggested to be related to the variation in subduction direction of the Paleo-Pacific plate beneath the Eurasian plate,from westward(pre-122 Ma)to west-northwestward(post-122 Ma).展开更多
Aboveground biomass(AGB)and belowground biomass(BGB)are key components of carbon storage,yet their responses to future climate changes remain poorly understood,particularly in China.Understanding these dynamics is ess...Aboveground biomass(AGB)and belowground biomass(BGB)are key components of carbon storage,yet their responses to future climate changes remain poorly understood,particularly in China.Understanding these dynamics is essential for global carbon cycle modeling and ecosystem management.This study integrates field observations,machine learning,and multi-source remote sensing data to reconstruct the distributions of AGB and BGB in China from 2000 to 2020.Then CMIP6 was used to predict the distribution of China under three SSP scenarios(SSP1-1.9,SSP2-4.5,SSP5-8.5)from 2020 to 2100 to fill the existing knowledge gap.The predictive accuracy for AGB(R^(2)=0.85)was significantly higher than for BGB(R^(2)=0.48),likely due to the greater complexity of modeling belowground dynamics.NDVI(Normalized Difference Vegetation Index)and soil organic carbon density(SOC)were identified as the primary drivers of AGB and BGB changes.During 2000-2020,AGB in China remained stable at approximately 10.69 Pg C,while BGB was around 5.06 Pg C.Forest ecosystems contributed 88.52% of AGB and 43.83% of BGB.AGB showed a relatively slow annual increase,while BGB demonstrated a significant annual growth rate of approximately 37 Tg C yr^(−1).Under the low-emission scenario,both AGB and BGB show fluctuations and steady growth,particularly in South China and the northwestern part of Northeast China.Under the moderate-emission scenario,AGB and BGB show significant declines and increases,respectively.In the high-emission scenario,both AGB and BGB decline significantly,particularly in the southwestern and central regions.These results provide valuable insights into ecosystem carbon dynamics under climate change,emphasizing the relatively low responsiveness of AGB and BGB to climatic variability,and offering guidance for sustainable land use and management strategies.展开更多
Ma Xingyuan(1919-2001),born in Changchun,Jilin Province.He graduated from the Department of Geology,Geography and Meteorology at National Southwestern Associated University in 1942 and obtained his doctoral degree fro...Ma Xingyuan(1919-2001),born in Changchun,Jilin Province.He graduated from the Department of Geology,Geography and Meteorology at National Southwestern Associated University in 1942 and obtained his doctoral degree from the University of Edinburgh,UK in 1948.He was elected as an Academician of the Chinese Academy of Sciences in 1980.He was an eminent structural geologist and seismologist.He achieved systematic groundbreaking research in Precambrian geology of North China,continental tectonics,lithospheric dynamics,and seismic geology.He pioneered analytical structural methodology and led the compilation of the"Lithospheric Dynamics Atlas of China",making foundational contributions to regional geological surveys and continental tectonic studies in China.展开更多
Li Chunyu(1904-1988),born in the Weihui City,Henan Province.He graduated from the Department of Geology at Peking University in 1928 and received his doctoral degree from the University of Berlin,Germany in 1937.He wa...Li Chunyu(1904-1988),born in the Weihui City,Henan Province.He graduated from the Department of Geology at Peking University in 1928 and received his doctoral degree from the University of Berlin,Germany in 1937.He was elected as an Academician of the Chinese Academy of Sciences in 1955.Li Chunyu was a renowned Chinese geologist and tectonist.He made significant contributions to the regional geological surveys,geological mapping,and mineral exploration in areas such as the Qinling Mountains,Sichuan Basin,and the Qinghai-Tibetan Plateau.Notably,he was the first to discover mélange in China and emerged as the leading figure advocating for the study of plate tectonic theory in the country.展开更多
In the published version of our article(Shaji et al.,2024),in the last paragraph of the article,Hong Kong should be corrected to Hong Kong(China)and the repetition of Spain and Ireland in the same sentence need to be ...In the published version of our article(Shaji et al.,2024),in the last paragraph of the article,Hong Kong should be corrected to Hong Kong(China)and the repetition of Spain and Ireland in the same sentence need to be deleted.The correct sentence is as below.展开更多
We document,for the first time,Mesoproterozoic-aged,continental arc magmatism in the Tasmanides.Granitoid samples intruding the Proterozoic Cape River Metamorphics in northeast Queensland contain abundant∼1200 Ma ign...We document,for the first time,Mesoproterozoic-aged,continental arc magmatism in the Tasmanides.Granitoid samples intruding the Proterozoic Cape River Metamorphics in northeast Queensland contain abundant∼1200 Ma igneous zircons,with early-Paleozoic metamorphic rim overgrowths.Analytical mixing between the igneous and metamorphic zircons produces cryptic discordant analyses,but the origin of said discordance is resolved with zircon Th/U ratios.Samples of the Fat Hen Creek Complex are peraluminous,calc-alkaline,S-type granitoids,that record high-grade metamorphism and trace element mobilization.The P3 and P42 intrusions are metaluminous,calc-alkaline,I-type granodiorite,which intruded the Cape River Metamorphics,and contain trace element signatures consistent with a continental-arc setting.We propose that a Mesoproterozoic continental terrane,herein referred to as the Oakvale Province,exists as basement to the Thomson Orogen.We propose several models for the formation of the Oakvale Province,with potential links to the Tarim Block,and the Yangtze Craton,during the late-Mesoproterozoic.We propose that the Oakvale Province supplied the Tasmanides with late-Mesoproterozoic detritus,and that such detritus was not solely sourced from the Musgrave Province as previously interpreted.Finally,we interpret the oroclinal bending of Paleozoic deformation and plutonic fabrics to reflect the buried extent of the Oakvale Province,and to potentially map out the Neoproterozoic rift margin associated with Rodinia break-up.展开更多
Agriculture is a major contributor to the global economy,accounting for approximately 70%of the freshwater use,which cause significant stress on aquifers in intensively irrigated regions.This stress often leads to the...Agriculture is a major contributor to the global economy,accounting for approximately 70%of the freshwater use,which cause significant stress on aquifers in intensively irrigated regions.This stress often leads to the decline in both the quantity and quality of groundwater resources.This study is focused on an intensively irrigated region of Northern India to investigate the sources and mechanism of groundwater recharge using a novel integrated approach combining isotope hydrology,Artificial Neural Network(ANN),and hydrogeochemical models.The study identifies several key sources of groundwater recharge,including natural precipitation,river infiltration,Irrigation Return Flow(IRF),and recharge from canals.Some groundwater samples exhibit mixing from various sources.Groundwater recharge from IRF is found to be isotopically enriched due to evaporation and characterized by high Cl−.Stable isotope modeling of evaporative enrichment in irrigated water helped to differentiate the IRF during various cultivation periods(Kharif and Rabi)and deduce the climatic conditions prevailed during the time of recharge.The model quantified that 29%of the irrigated water is lost due to evaporation during the Kharif period and 20%during the Rabi period,reflecting the seasonal variations in IRF contribution to the groundwater.The ANN model,trained with isotope hydrogeochemical data,effectively captures the complex interrelationships between various recharge sources,providing a robust framework for understanding the groundwater dynamics in the study area.A conceptual model was developed to visualize the spatial and temporal distribution of recharge sources,highlighting how seasonal irrigation practices influence the groundwater.The integration of isotope hydrology with ANN methodologies proved to be effective in elucidating the multiple sources and processes of groundwater recharge,offering insights into the sustainability of aquifer systems in intensively irrigated regions.These findings are critical for developing data-driven groundwater management strategies that can adapt to future challenges,including climate change,shifting land use patterns,and evolving agricultural demands.The results have significant implications for policymakers and water resource managers seeking to ensure sustainable groundwater use in water-scarce regions.展开更多
Large-scale Danian-age(post-K/Pg boundary)Deccan magmatism is well known from the Mumbai metropolitan area,located in the structurally complex Panvel flexure zone along the western Indian rifted continental margin.Thi...Large-scale Danian-age(post-K/Pg boundary)Deccan magmatism is well known from the Mumbai metropolitan area,located in the structurally complex Panvel flexure zone along the western Indian rifted continental margin.This compositionally diverse late-Deccan magmatic suite contains subaerial tholeiitic lavas and dykes typical of the main Deccan province,with many features atypical of the Deccan,such as spilitic pillow lavas,“intertrappean”sediments(often containing considerable volcanic ash),rhyolitic lavas and tuffs,gabbro-granophyre intrusions,and trachyte intrusions containing alkali basalt enclaves.Most of these units,previously dated at 62.5 Ma to 61 Ma,are contemporaneous with or slightly postdate the 62.5 Ma India-Seychelles continental breakup and Panvel flexure formation.In the Dongri-Uttan area,two samples of a>50-m-thick,columnar-jointed rhyolite from the Darkhan Quarry and from a section behind the current Uttan Sagari Police Station have previously been dated at 62.6±0.6 Ma and 62.9±0.2 Ma(^(40)Ar/^(39)Ar,2r errors).New exposures reveal that these two statistically indistinguishable 40 Ar/39 Ar ages correspond to two distinct rhyolite units,separated by well-bedded silicic ash.The columnar rhyolites are microcrystalline,composed of quartz and alkali feldspar,with rare small(1–2 mm),altered feldspar phenocrysts,and no recognisable relict vitroclasts.Given the westerly structural dip,most of their lateral extent is submerged under the Arabian Sea,and we consider them to be possible flood rhyolite lavas.We interpret the ash beds,composed of pumice clasts and glass shards,as a low-grade(nonwelded)vitric ash,derived from a possibly distal Plinian eruption and deposited by fallout.The lavas and ash are peraluminous rhyolites.The lavas are Sr-Ba-poor and Rb-Zr-Nb-rich,and show“seagull-shaped”rare earth element patterns with deep negative europium anomalies.These crystal-poor lavas are“hot-dry-reduced”rhyolites typical of intraplate,continental rift and rifted margin settings.The very different high-field strength element contents of the lavas and the ash indicate compositionally distinct magma batches.The 62.5 Ma Dongri-Uttan sequence provides clear evidence for rapid silicic eruptions of effusive and explosive nature,alternating with each other and sourced from distinct magma chambers and eruptive vents.A newly identified,highly feldspar-phyric trachyte intrusion marks the last phase of magmatic activity in the area,corresponding with late-stage trachyte-syenite intrusions exposed in coastal western India and the Seychelles,and shows that the Mumbai rhyolites and trachytes form a compositional continuum.展开更多
The mechanical properties of minerals in planetary materials are not only interesting from a fundamental point of view but also critical to the development of future space missions.Here we present nanoindentation expe...The mechanical properties of minerals in planetary materials are not only interesting from a fundamental point of view but also critical to the development of future space missions.Here we present nanoindentation experiments to evaluate the hardness and reduced elastic modulus of olivine,(Mg,Fe)_(2)SiO_(4),in meteorite NWA 12008,a lunar basalt.Our experiments suggest that the olivine grains in this lunaite are softer and more elastic than their terrestrial counterparts.Also,we have performed synchrotron-based high-pressure X-ray diffraction(HP-XRD)measurements to probe the compressibility properties of olivine in this meteorite and,for comparison purposes,of three ordinary chondrites.The HP-XRD results suggest that the axial compressibility of the orthorhombic b lattice parameter of olivine relative to terrestrial olivine is higher in NWA 12008 and also in the highly-shocked Chelyabinsk meteorite.The origin of the observed differences is discussed.A simple model combining the results of both our nanoindentation and HP-XRD measurements allows us to describe the contribution of macroscopic and chemical-bond related effects,both of which are necessary to reproduce the observed elastic modulus softening.Such joint analysis of the mechanical and elastic properties of meteorites and returned samples opens up a new avenue for characterizing these highly interesting materials.展开更多
When interpreting results,it is imperative to have some understanding of the degree to which the results are replicable.If the results cannot be replicated with independent data,then interpretations from the results b...When interpreting results,it is imperative to have some understanding of the degree to which the results are replicable.If the results cannot be replicated with independent data,then interpretations from the results become questionable.To minimize the potential for misinterpretations,the current study analyzes six time-series derived from globally sampled U-Pb zircon databases–of which,two are independent igneous databases,one being a quasi-independent igneous database,and three being independent detrital databases.These time-series are then analyzed with standard statistical methods to evaluate replicability.The methods include bandpass filtering to transform the raw time-series into stationary sequences,Student’s t-test,Monte Carlo simulations,periodograms from spectral analysis,correlation studies,and correlograms.Each test is designed to determine the replicability of a specific time-series,as well as the replicability of periodicities found from the time-series.The results show at least three key components to assessing replicability:(a)U-Pb igneous and detrital zircon age distributions are highly replicable,(b)time-series replicability gradually deteriorates with age,and(c)replicability is scale dependent,with low frequency cycles being more replicable than high frequency cycles.From the tests,we conclude that four harmonic cycles are highly replicable and statistically significant,these being periodicities of 810,270,90,and 67.5-myr.展开更多
The Jizhong-Yanbian Cu-Mo-Au-Pb-Zn polymetallic metallogenic belt is a major nonferrous and precious metal resource base in Northeastern China.The genesis of ore deposits in this district has remained controversial.To...The Jizhong-Yanbian Cu-Mo-Au-Pb-Zn polymetallic metallogenic belt is a major nonferrous and precious metal resource base in Northeastern China.The genesis of ore deposits in this district has remained controversial.To constrain ore genetic models and provide information for exploration,we conducted precise Zn-Cd isotopic measurements on sphalerite and galena.Theδ^(66)Zn_(AA-ETH)values of galena and sphalerite range from−0.07‰to 0.03‰and−0.68‰to−0.12‰,respectively;and theirδ^(114/110)Cd_(NIST SRM 3108)values vary from−0.96‰to 3.83‰and−0.63‰to 0.77‰,respectively.Our study suggests that the Xiaohongshilazi Pb-Zn-(Ag)deposit should be classified as a Mississippi Valley Type(MVT)-like deposit,because both its geological,sulfide trace elemental,and S-Pb-Fe-Zn-Cd isotopic characteristics are similar to those of the typical MVT deposit,except for the differences of the wall rocks.Rayleigh fractionation during sphalerite precipitation is identified as the primary mechanism for Zn-Cd isotopic variations,which is validated by the Zn-Cd fractionation models from 100℃to 250℃.Finally,we propose an ore prospecting model based on migration pathways of ore-forming fluid and the Zn isotopic fractionation model of sphalerite under 100℃.This model indicates potential resources undiscovered at shallow/peripheral and deep zones of current mining level in both the Eastern and Western Ore Block,with parts of the potential resources having been corroborated by recent drilling.Despite the complexity of mineralization,processes,this study provides new insights into the application of Zn-Cd isotopes in understanding ore genesis and guiding mineral exploration in similar contexts.展开更多
文摘The 2024 Geoscience Frontiers Annual Convention was held in Kuching,Malaysia,from November 18th to 22th,2024,jointly with the 2024 IAGR Annual Convention and the 21st International Conference on Gondwana to Asia.The IAGR Convention attracted over 150 participants from various countries,including China,India,Australia,the Republic of Korea,Japan,Malaysia,Indonesia,Thailand,Italy,Mexico,the United Kingdom,Saudi Arabia,France,and Brunei.
文摘1AIM AND SCOPE Geoscience Frontiers(GSF)publishes peer reviewed research articles and reviews in interdisciplinary fields of Earth and Planetary Sciences.GSF bridges innovative,provocative and challenging concepts and models related to various fields of research including petrology and geochemistry in understanding lithospheric architecture and mantle dynamics,global tectonics,economic geology and fuel exploration,geophysics,stratigraphy and paleontology with insights on correlations and evolution,environmental and engineering geology,astrogeology,nexus of resources-energy-emissions-climate under Sustainable Development Goals,among other themes.
文摘1AIMANDSCOPE Geoscience Frontiers(GSF)publishes peer reviewed research articles and reviews in interdisciplinary fields of Earth and Planetary Sciences.GSF bridges innovative,provocative and challenging concepts and models related to various fields of research including petrology and geochemistry in understanding lithospheric architecture and mantle dynamics,global tectonics,economic geology and fuel exploration,geophysics,stratigraphy and paleontology with insights on correlations and evolution,environmental and engineering geology,astrogeology,nexus of resources-energy-emissions-climate under Sustainable Development Goals,among other themes.
文摘1AIM AND SCOPE Geoscience Frontiers(GSF)publishes peer reviewed research articles and reviews in interdisciplinary fields of Earth and Planetary Sciences.
文摘The contributions of our referees remain vital to maintaining the high quality of papers published in Geoscience Frontiers.Their thoughtful critiques,dedication to reviewing,and,on occasion,re-reviewing manuscripts submitted to the journal are deeply appreciated by boththe Editors and the Publisher.We would like to take this opportunity to extend our heartfelt thanks to the following referees for theirinvaluable input and support in reviewing manuscripts submitted in 2024.
基金supported by the Centre for Advanced Modelling and Geospatial Information Systems(CAMGIS),University of Technology Sydney(UTS),Australia and was supported by the Research Training Program(RTP)of the Australian Government.
文摘Hurricanes are one of the most destructive natural disasters that can cause catastrophic losses to both communities and infrastructure.Assessment of hurricane risk furnishes a spatial depiction of the interplay among hazard,vulnerability,exposure,and mitigation capacity,crucial for understanding and managing the risks hurricanes pose to communities.These assessments aid in gauging the efficacy of existing hurricane mitigation strategies and gauging their resilience across diverse climate change scenarios.A systematic review was conducted,encompassing 94 articles,to scrutinize the structure,data inputs,assumptions,methodologies,perils modelled,and key predictors of hurricane risk.This review identified key research gaps essential for enhancing future risk assessments.The complex interaction between hurricane perils may be disastrous and underestimated in the majority of risk assessments which focus on a single peril,commonly storm surge and flood,resulting in inadequacies in disaster resilience planning.Most risk assessments were based on hurricane frequency rather than hurricane damage,which is more insightful for policymakers.Furthermore,considering secondary indirect impacts stemming from hurricanes,including real estate market and business interruption,could enrich economic impact assessments.Hurricane mitigation measures were the most under-utilised category of predictors leveraged in only 5%of studies.The top six predictive factors for hurricane risk were land use,slope,precipitation,elevation,population density,and soil texture/drainage.Another notable research gap identified was the potential of machine learning techniques in risk assessments,offering advantages over traditional MCDM and numerical models due to their ability to capture complex nonlinear relationships and adaptability to different study regions.Existing machine learning based risk assessments leverage random forest models(42%of studies)followed by neural network models(19%of studies),with further research required to investigate diverse machine learning algorithms such as ensemble models.A further research gap is model validation,in particular assessing transferability to a new study region.Additionally,harnessing simulated data and refining projections related to demographic and built environment dynamics can bolster the sophistication of climate change scenario assessments.By addressing these research gaps,hurricane risk assessments can furnish invaluable insights for national policymakers,facilitating the development of robust hurricane mitigation strategies and the construction of hurricane-resilient communities.To the authors’knowledge,this represents the first literature review specifically dedicated to quantitative hurricane risk assessments,encompassing a comparison of Multi-criteria Decision Making(MCDM),numerical models,and machine learning models.Ultimately,advancements in hurricane risk assessments and modelling stand poised to mitigate potential losses to communities and infrastructure both in the immediate and long-term future.
文摘Energy poverty in developing countries is a critical issue characterized by the lack of access to modern energy services,such as electricity and clean cooking facilities,as marked in SDG 7.This study explores the correlations between energy poverty,energy intensity,resource abundance,and income inequality,as these factors have been theorized to play important roles in influencing energy poverty in developing countries.By observing that the dataset is heterogeneous across the countries and over the time frame,we use the Method of Moments Quantile Regression(MMQR)to analyze our developing countries’data from 2000 to 2019.Our findings indicate that energy intensity is a significant factor influencing energy poverty,suggesting that higher energy consumption relative to the sample countries can exacerbate this issue.Additionally,we observe that income inequality within the sample countries is a critical determinant of energy poverty levels,highlighting the dynamics between economic disparity and access to energy resources.Interestingly,our study reveals that resource abundance acts as a blessing rather than a curse in terms of energy poverty,implying that countries rich in natural resources may have better opportunities to combat energy deprivation.Finally,we emphasize the vital role of financial markets in addressing energy poverty on a global scale,suggesting that robust financial systems can facilitate investments and innovations aimed at improving energy access for vulnerable populations.The results from the robustness analysis support the empirical results obtained from the main estimation.The empirical findings of the present study advance important comprehensions for policymakers to adopt energy policies that address the complex challenges of energy poverty and promote inclusive energy access.
基金supported by the Guangdong Province Introduced Innovative R&D Team of Big Data-Mathematical Earth Sciences and Extreme Geological Events Team(grant number 2021ZT09H399)the National Natural Science Foundation of China(grant number 42430111,42050103).
文摘The investigations of physical attributes of oceans,including parameters such as heat flow and bathymetry,have garnered substantial attention and are particularly valuable for examining Earth’s thermal structures and dynamic processes.Nevertheless,classical plate cooling models exhibit disparities when predicting observed heat flow and seafloor depth for extremely young and old lithospheres.Furthermore,a comprehensive analysis of global heat flow predictions and regional ocean heat flow or bathymetry data with physical models has been lacking.In this study,we employed power-law models derived from the singularity theory of fractal density to meticulously fit the latest ocean heat flow and bathymetry.Notably,power-law models offer distinct advantages over traditional plate cooling models,showcasing robust self-similarity,scale invariance,or scaling properties,and providing a better fit to observed data.The outcomes of our singularity analysis concerning heat flow and bathymetry across diverse oceanic regions exhibit a degree of consistency with the global ocean spreading rate model.In addition,we applied the similarity method to predict a higher resolution(0.1°×0.1°)global heat flow map based on the most recent heat flow data and geological/geophysical observables refined through linear correlation analysis.Regions displaying significant disparities between predicted and observed heat flow are closely linked to hydrothermal vent fields and active structures.Finally,combining the actual bathymetry and predicted heat flow with the power-law models allows for the quantitative and comprehensive detection of anomalous regions of ocean subsidence and heat flow,which deviate from traditional plate cooling models.The anomalous regions of subsidence and heat flow show different degrees of anisotropy,providing new ideas and clues for further analysis of ocean topography or hydrothermal circulation of mid-ocean ridges.
基金the National Key Research and Development Program of China(2021YFC2900300)the Natural Science Foundation of Guangdong Province(2024A1515030216)+2 种基金MOST Special Fund from State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(GPMR202437)the Guangdong Province Introduced of Innovative R&D Team(2021ZT09H399)the Third Xinjiang Scientific Expedition Program(2022xjkk1301).
文摘The application of machine learning for pyrite discrimination establishes a robust foundation for constructing the ore-forming history of multi-stage deposits;however,published models face challenges related to limited,imbalanced datasets and oversampling.In this study,the dataset was expanded to approximately 500 samples for each type,including 508 sedimentary,573 orogenic gold,548 sedimentary exhalative(SEDEX)deposits,and 364 volcanogenic massive sulfides(VMS)pyrites,utilizing random forest(RF)and support vector machine(SVM)methodologies to enhance the reliability of the classifier models.The RF classifier achieved an overall accuracy of 99.8%,and the SVM classifier attained an overall accuracy of 100%.The model was evaluated by a five-fold cross-validation approach with 93.8%accuracy for the RF and 94.9%for the SVM classifier.These results demonstrate the strong feasibility of pyrite classification,supported by a relatively large,balanced dataset and high accuracy rates.The classifier was employed to reveal the genesis of the controversial Keketale Pb-Zn deposit in NW China,which has been inconclusive among SEDEX,VMS,or a SEDEX-VMS transition.Petrographic investigations indicated that the deposit comprises early fine-grained layered pyrite(Py1)and late recrystallized pyrite(Py2).The majority voting classified Py1 as the VMS type,with an accuracy of RF and SVM being 72.2%and 75%,respectively,and confirmed Py2 as an orogenic type with 74.3% and 77.1%accuracy,respectively.The new findings indicated that the Keketale deposit originated from a submarine VMS mineralization system,followed by late orogenic-type overprinting of metamorphism and deformation,which is consistent with the geological and geochemical observations.This study further emphasizes the advantages of Machine learning(ML)methods in accurately and directly discriminating the deposit types and reconstructing the formation history of multi-stage deposits.
基金supported by the National Natural Science Foundation of China(Grant Nos:42130801,41430211,90814006,and 42072226)the“Deep-time Digital Earth”Science and Technology Leading Talents Team Funds for the Central Universities for the Frontiers Science Center for Deep-time Digital Earth,CUGB(Fundamental Research Funds for the Central UniversitiesGrant No:2652023001).
文摘How the subduction direction of the Paleo-Pacific plate beneath the Eurasian plate changes in the Early Cretaceous remains highly controversial due to the disappearance of the subducted oceanic plate.Intraplate deformation structures in the east Asian continent,however,provide excellent opportunities for reconstructing paleostress fields in continental interior in relation to the Paleo-Pacific/Eurasian plate interaction.Anisotropy of magnetic susceptibility(AMS),geological,and geochronological analyses of post-kinematic mafic dykes intruding the detachment fault zone of the Wulian metamorphic core complex(WL MCC)in Jiaodong Peninsula exemplify emplacement of mantle-sourced dykes in a WNW-ESE(301°-121°)oriented tectonic extensional setting at ca.120 Ma.In combination with the results from our previous kinematic analysis of the MCC,a ca.21°clockwise change in the direction of intraplate extension is obtained for early(135-122 Ma)extensional exhumation of the MCC to late(122-108 Ma)emplacement of the dykes.Such a change is suggested to be related to the variation in subduction direction of the Paleo-Pacific plate beneath the Eurasian plate,from westward(pre-122 Ma)to west-northwestward(post-122 Ma).
基金supported by the Tianchi Talent-Young Doctor Program of the Xinjiang Uygur Autonomous Region,the Innovation Training Program for Undergraduates at the Autonomous Region Level in 2024(Grant No.S202410755009)the Innovation Training Program for Undergraduates at the University Level in 2024(Grant No.XJU-SRT-24008)+3 种基金the National Innovation Training Program for College Students in 2024(Grant No.202410755009)the National Natural Science Foundation of China(Grant No.42401065)the Basic and Applied Basic Research Program of Guangdong Province,China(Grant No.2023A1515011273)the Research Projects of the Department of Education of Guangdong Province(Grant No.2023KTSCX315).
文摘Aboveground biomass(AGB)and belowground biomass(BGB)are key components of carbon storage,yet their responses to future climate changes remain poorly understood,particularly in China.Understanding these dynamics is essential for global carbon cycle modeling and ecosystem management.This study integrates field observations,machine learning,and multi-source remote sensing data to reconstruct the distributions of AGB and BGB in China from 2000 to 2020.Then CMIP6 was used to predict the distribution of China under three SSP scenarios(SSP1-1.9,SSP2-4.5,SSP5-8.5)from 2020 to 2100 to fill the existing knowledge gap.The predictive accuracy for AGB(R^(2)=0.85)was significantly higher than for BGB(R^(2)=0.48),likely due to the greater complexity of modeling belowground dynamics.NDVI(Normalized Difference Vegetation Index)and soil organic carbon density(SOC)were identified as the primary drivers of AGB and BGB changes.During 2000-2020,AGB in China remained stable at approximately 10.69 Pg C,while BGB was around 5.06 Pg C.Forest ecosystems contributed 88.52% of AGB and 43.83% of BGB.AGB showed a relatively slow annual increase,while BGB demonstrated a significant annual growth rate of approximately 37 Tg C yr^(−1).Under the low-emission scenario,both AGB and BGB show fluctuations and steady growth,particularly in South China and the northwestern part of Northeast China.Under the moderate-emission scenario,AGB and BGB show significant declines and increases,respectively.In the high-emission scenario,both AGB and BGB decline significantly,particularly in the southwestern and central regions.These results provide valuable insights into ecosystem carbon dynamics under climate change,emphasizing the relatively low responsiveness of AGB and BGB to climatic variability,and offering guidance for sustainable land use and management strategies.
文摘Ma Xingyuan(1919-2001),born in Changchun,Jilin Province.He graduated from the Department of Geology,Geography and Meteorology at National Southwestern Associated University in 1942 and obtained his doctoral degree from the University of Edinburgh,UK in 1948.He was elected as an Academician of the Chinese Academy of Sciences in 1980.He was an eminent structural geologist and seismologist.He achieved systematic groundbreaking research in Precambrian geology of North China,continental tectonics,lithospheric dynamics,and seismic geology.He pioneered analytical structural methodology and led the compilation of the"Lithospheric Dynamics Atlas of China",making foundational contributions to regional geological surveys and continental tectonic studies in China.
文摘Li Chunyu(1904-1988),born in the Weihui City,Henan Province.He graduated from the Department of Geology at Peking University in 1928 and received his doctoral degree from the University of Berlin,Germany in 1937.He was elected as an Academician of the Chinese Academy of Sciences in 1955.Li Chunyu was a renowned Chinese geologist and tectonist.He made significant contributions to the regional geological surveys,geological mapping,and mineral exploration in areas such as the Qinling Mountains,Sichuan Basin,and the Qinghai-Tibetan Plateau.Notably,he was the first to discover mélange in China and emerged as the leading figure advocating for the study of plate tectonic theory in the country.
文摘In the published version of our article(Shaji et al.,2024),in the last paragraph of the article,Hong Kong should be corrected to Hong Kong(China)and the repetition of Spain and Ireland in the same sentence need to be deleted.The correct sentence is as below.
文摘We document,for the first time,Mesoproterozoic-aged,continental arc magmatism in the Tasmanides.Granitoid samples intruding the Proterozoic Cape River Metamorphics in northeast Queensland contain abundant∼1200 Ma igneous zircons,with early-Paleozoic metamorphic rim overgrowths.Analytical mixing between the igneous and metamorphic zircons produces cryptic discordant analyses,but the origin of said discordance is resolved with zircon Th/U ratios.Samples of the Fat Hen Creek Complex are peraluminous,calc-alkaline,S-type granitoids,that record high-grade metamorphism and trace element mobilization.The P3 and P42 intrusions are metaluminous,calc-alkaline,I-type granodiorite,which intruded the Cape River Metamorphics,and contain trace element signatures consistent with a continental-arc setting.We propose that a Mesoproterozoic continental terrane,herein referred to as the Oakvale Province,exists as basement to the Thomson Orogen.We propose several models for the formation of the Oakvale Province,with potential links to the Tarim Block,and the Yangtze Craton,during the late-Mesoproterozoic.We propose that the Oakvale Province supplied the Tasmanides with late-Mesoproterozoic detritus,and that such detritus was not solely sourced from the Musgrave Province as previously interpreted.Finally,we interpret the oroclinal bending of Paleozoic deformation and plutonic fabrics to reflect the buried extent of the Oakvale Province,and to potentially map out the Neoproterozoic rift margin associated with Rodinia break-up.
基金This study was conducted as a part of the IAEA Co-ordinated Research Project(CRP)“Isotope techniques for the evaluation of water sources in irrigation systems(F-33025)”。
文摘Agriculture is a major contributor to the global economy,accounting for approximately 70%of the freshwater use,which cause significant stress on aquifers in intensively irrigated regions.This stress often leads to the decline in both the quantity and quality of groundwater resources.This study is focused on an intensively irrigated region of Northern India to investigate the sources and mechanism of groundwater recharge using a novel integrated approach combining isotope hydrology,Artificial Neural Network(ANN),and hydrogeochemical models.The study identifies several key sources of groundwater recharge,including natural precipitation,river infiltration,Irrigation Return Flow(IRF),and recharge from canals.Some groundwater samples exhibit mixing from various sources.Groundwater recharge from IRF is found to be isotopically enriched due to evaporation and characterized by high Cl−.Stable isotope modeling of evaporative enrichment in irrigated water helped to differentiate the IRF during various cultivation periods(Kharif and Rabi)and deduce the climatic conditions prevailed during the time of recharge.The model quantified that 29%of the irrigated water is lost due to evaporation during the Kharif period and 20%during the Rabi period,reflecting the seasonal variations in IRF contribution to the groundwater.The ANN model,trained with isotope hydrogeochemical data,effectively captures the complex interrelationships between various recharge sources,providing a robust framework for understanding the groundwater dynamics in the study area.A conceptual model was developed to visualize the spatial and temporal distribution of recharge sources,highlighting how seasonal irrigation practices influence the groundwater.The integration of isotope hydrology with ANN methodologies proved to be effective in elucidating the multiple sources and processes of groundwater recharge,offering insights into the sustainability of aquifer systems in intensively irrigated regions.These findings are critical for developing data-driven groundwater management strategies that can adapt to future challenges,including climate change,shifting land use patterns,and evolving agricultural demands.The results have significant implications for policymakers and water resource managers seeking to ensure sustainable groundwater use in water-scarce regions.
基金supported by the research award project RI/0220-10000618-001 to Sheth from the Industrial Research and Consultancy Centre(IRCC)IIT Bombay.Shekhar and Astha were supported by Prime Minister’s Research Fellowships(PMRF,File Nos.1303100 and 1303103,respectively)+4 种基金Naik was initially supported by an IIT Bombay Institute Post-Doctoral Fellowship(File No.HR-1(HRM-1)/Rect/33/2022/20003002)subsequently by a Goa State Research Foundation Post-doctoral Fellowship(File No.PDF2024003)We express our sincere gratitude to Prof.N.Prabhakar for kindly granting us access to the WD-XRF spectrometry facility(SIP ProjectWBS Code:IN/22-1111039E-01)the ICP-MS facility,and the SERB-funded EPMA National Facility(IRPHA Grant No.IR/S4/ESF-16/2009(G))in the Department of Earth Sciences,IIT Bombay.
文摘Large-scale Danian-age(post-K/Pg boundary)Deccan magmatism is well known from the Mumbai metropolitan area,located in the structurally complex Panvel flexure zone along the western Indian rifted continental margin.This compositionally diverse late-Deccan magmatic suite contains subaerial tholeiitic lavas and dykes typical of the main Deccan province,with many features atypical of the Deccan,such as spilitic pillow lavas,“intertrappean”sediments(often containing considerable volcanic ash),rhyolitic lavas and tuffs,gabbro-granophyre intrusions,and trachyte intrusions containing alkali basalt enclaves.Most of these units,previously dated at 62.5 Ma to 61 Ma,are contemporaneous with or slightly postdate the 62.5 Ma India-Seychelles continental breakup and Panvel flexure formation.In the Dongri-Uttan area,two samples of a>50-m-thick,columnar-jointed rhyolite from the Darkhan Quarry and from a section behind the current Uttan Sagari Police Station have previously been dated at 62.6±0.6 Ma and 62.9±0.2 Ma(^(40)Ar/^(39)Ar,2r errors).New exposures reveal that these two statistically indistinguishable 40 Ar/39 Ar ages correspond to two distinct rhyolite units,separated by well-bedded silicic ash.The columnar rhyolites are microcrystalline,composed of quartz and alkali feldspar,with rare small(1–2 mm),altered feldspar phenocrysts,and no recognisable relict vitroclasts.Given the westerly structural dip,most of their lateral extent is submerged under the Arabian Sea,and we consider them to be possible flood rhyolite lavas.We interpret the ash beds,composed of pumice clasts and glass shards,as a low-grade(nonwelded)vitric ash,derived from a possibly distal Plinian eruption and deposited by fallout.The lavas and ash are peraluminous rhyolites.The lavas are Sr-Ba-poor and Rb-Zr-Nb-rich,and show“seagull-shaped”rare earth element patterns with deep negative europium anomalies.These crystal-poor lavas are“hot-dry-reduced”rhyolites typical of intraplate,continental rift and rifted margin settings.The very different high-field strength element contents of the lavas and the ash indicate compositionally distinct magma batches.The 62.5 Ma Dongri-Uttan sequence provides clear evidence for rapid silicic eruptions of effusive and explosive nature,alternating with each other and sourced from distinct magma chambers and eruptive vents.A newly identified,highly feldspar-phyric trachyte intrusion marks the last phase of magmatic activity in the area,corresponding with late-stage trachyte-syenite intrusions exposed in coastal western India and the Seychelles,and shows that the Mumbai rhyolites and trachytes form a compositional continuum.
基金Financial support from the project PID2021-128062NB-I00 funded by the Spanish Ministerio de Ciencia,Innovación y Universidades MCIU(doi:10.13039/501100011033)is acknowledged,as well as the Spanish program Unidad de Excelencia María de Maeztu CEX2020-001058-M.The ALBA-CELLS synchrotron is acknowledged for granting beamtime at the MSPD beamline under projects 2021095390 and 2022025734.PG-T acknowledges the financial support from the Spanish MCIU through the FPI predoctoral fellowship PRE2022-104624.JS acknowledges the financial support from projects 2021-SGR-00651 and PID2020-116844RB-C21.EP-A acknowledges financial support from the LUMIO project funded by the Agenzia Spaziale Italiana(2024-6-HH.0).DE thanks the financial support from Spanish MCIU under projects PID2022-138076NB-C41 and RED2022-134388-T from Generalitat Valenciana(GVA)through grants CIPROM/2021/075 and MFA/2022/007,which are part of the Advanced Materials program and is supported with funding from the European Union Next Generation EU(PRTR-C17.I1).RT and DE(PB and DE)thank GVA for the Postdoctoral Fellowship CIAPOS/2021/20(CIAPOS/2023/406).JS-M thanks the Spanish MCIU for the PRE2020-092198 fellowship.NWA 12008 has been studied within the framework of an international European consortium led by IFP.Special acknowledge to I.Weber for providing the NWA 12008 meteorite thin section.This work is part of the doctoral thesis of PG-T(Doctoral Program in Physics at Universitat Autònoma de Barcelona).
文摘The mechanical properties of minerals in planetary materials are not only interesting from a fundamental point of view but also critical to the development of future space missions.Here we present nanoindentation experiments to evaluate the hardness and reduced elastic modulus of olivine,(Mg,Fe)_(2)SiO_(4),in meteorite NWA 12008,a lunar basalt.Our experiments suggest that the olivine grains in this lunaite are softer and more elastic than their terrestrial counterparts.Also,we have performed synchrotron-based high-pressure X-ray diffraction(HP-XRD)measurements to probe the compressibility properties of olivine in this meteorite and,for comparison purposes,of three ordinary chondrites.The HP-XRD results suggest that the axial compressibility of the orthorhombic b lattice parameter of olivine relative to terrestrial olivine is higher in NWA 12008 and also in the highly-shocked Chelyabinsk meteorite.The origin of the observed differences is discussed.A simple model combining the results of both our nanoindentation and HP-XRD measurements allows us to describe the contribution of macroscopic and chemical-bond related effects,both of which are necessary to reproduce the observed elastic modulus softening.Such joint analysis of the mechanical and elastic properties of meteorites and returned samples opens up a new avenue for characterizing these highly interesting materials.
基金supported by the French Agence Nationale de la Recherche(19-CE31-0002 AstroMeso)the European Research Council under the European Union’s Horizon 2020 Research and Innovation Program(Advanced Grant AstroGeo-885250).
文摘When interpreting results,it is imperative to have some understanding of the degree to which the results are replicable.If the results cannot be replicated with independent data,then interpretations from the results become questionable.To minimize the potential for misinterpretations,the current study analyzes six time-series derived from globally sampled U-Pb zircon databases–of which,two are independent igneous databases,one being a quasi-independent igneous database,and three being independent detrital databases.These time-series are then analyzed with standard statistical methods to evaluate replicability.The methods include bandpass filtering to transform the raw time-series into stationary sequences,Student’s t-test,Monte Carlo simulations,periodograms from spectral analysis,correlation studies,and correlograms.Each test is designed to determine the replicability of a specific time-series,as well as the replicability of periodicities found from the time-series.The results show at least three key components to assessing replicability:(a)U-Pb igneous and detrital zircon age distributions are highly replicable,(b)time-series replicability gradually deteriorates with age,and(c)replicability is scale dependent,with low frequency cycles being more replicable than high frequency cycles.From the tests,we conclude that four harmonic cycles are highly replicable and statistically significant,these being periodicities of 810,270,90,and 67.5-myr.
基金supported by the Open Research Project from the Young Elite Scientists Sponsorship Program by BAST(No.BYESS2023411)the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(GPMR202407)the Enterprise Authorized Item from Jilin Sanhe Mining Development Co.LTD(3-4-2021-120).
文摘The Jizhong-Yanbian Cu-Mo-Au-Pb-Zn polymetallic metallogenic belt is a major nonferrous and precious metal resource base in Northeastern China.The genesis of ore deposits in this district has remained controversial.To constrain ore genetic models and provide information for exploration,we conducted precise Zn-Cd isotopic measurements on sphalerite and galena.Theδ^(66)Zn_(AA-ETH)values of galena and sphalerite range from−0.07‰to 0.03‰and−0.68‰to−0.12‰,respectively;and theirδ^(114/110)Cd_(NIST SRM 3108)values vary from−0.96‰to 3.83‰and−0.63‰to 0.77‰,respectively.Our study suggests that the Xiaohongshilazi Pb-Zn-(Ag)deposit should be classified as a Mississippi Valley Type(MVT)-like deposit,because both its geological,sulfide trace elemental,and S-Pb-Fe-Zn-Cd isotopic characteristics are similar to those of the typical MVT deposit,except for the differences of the wall rocks.Rayleigh fractionation during sphalerite precipitation is identified as the primary mechanism for Zn-Cd isotopic variations,which is validated by the Zn-Cd fractionation models from 100℃to 250℃.Finally,we propose an ore prospecting model based on migration pathways of ore-forming fluid and the Zn isotopic fractionation model of sphalerite under 100℃.This model indicates potential resources undiscovered at shallow/peripheral and deep zones of current mining level in both the Eastern and Western Ore Block,with parts of the potential resources having been corroborated by recent drilling.Despite the complexity of mineralization,processes,this study provides new insights into the application of Zn-Cd isotopes in understanding ore genesis and guiding mineral exploration in similar contexts.
