East Asian continental tectonics challenges the plate tectonics paradigm with its diffuse intraplate deformation,magmatism,and earthquakes.Despite extensive studies,fundamental questions persist.This review examines t...East Asian continental tectonics challenges the plate tectonics paradigm with its diffuse intraplate deformation,magmatism,and earthquakes.Despite extensive studies,fundamental questions persist.This review examines ten critical questions of East Asian tectonics,including the thickness of the continental lithosphere,the origin of the North–South Gravity Lineament,and the northern extent of the Indian plate beneath the Tibetan Plateau.Additional questions address the Tibetan Plateau's lateral growth,the Tianshan mountain building,the mantle flow in response to the Indo-Asian collision,and the formation of the Shanxi Rift.The review also explores the subduction along the eastern margins of the East Asian Continent and the origins of the Changbaishan volcanic field,the destruction of the North China Craton,and the development of the Mesozoic Large Granitic Province in South China.Originally presented at the DEEP2024 workshop to stimulate discussion of how SinoProbe-II research initiatives could advance our understanding of Asian tectonics,this review provides context for each question,summarizes current knowledge,and identifies promising research directions.展开更多
Leucogranite,pegmatite,and aplite from selected areas in the Wadi El Gemal area in the southern Eastern Desert of Egypt were investigated geochemically for their petrogenesis.These rocks represent a significant episod...Leucogranite,pegmatite,and aplite from selected areas in the Wadi El Gemal area in the southern Eastern Desert of Egypt were investigated geochemically for their petrogenesis.These rocks represent a significant episode of felsic magmatism during the late stage of the Pan-African orogeny in the evolution of the Arabian–Nubian Shield(ANS)during the Late Neoproterozoic.On a petrographic basis,the leucogranite is sometimes garnetiferous and can be distinguished into monzogranite,syenogranite,and alkali feldspar granite.The analyses of muscovite,biotite,garnet,and apatite reveal the magmatic nature of the studied leucogranite.The investigated leucogranite,pegmatite,and aplite are alkali-calcic,calc-alkaline,and peraluminous.The peraluminous nature of these rocks is evidenced by using the chemical analyses of biotite.These studied rocks show a slight enrichment in light rare-earth elements(LREEs)and large-ion lithophile elements(LILE,especially Rb and Th),with an insignificant depletion of heavy rareearth elements(HREEs).On a geochemical basis,the leucogranite,pegmatite,and aplite in the study area crystallized from multiple-sourced melts that include mafic,metagraywake,and pelitic.They were derived from melts generated at crystallization temperatures around 568-900℃ for leucogranite,553-781℃ for pegmatite,and 639-779℃ for aplite based on the Zr saturation geothermometers,and at a pressure around 0.39-0.48 GPa,i.e.shallow depth intrusions.The studied felsic rocks have strong negative Eu anomalies,which are very consistent with an upper crust composition,indicating fractionation of feldspar cumulates.Also,they show a moderate La/Sm ratio indicating combined magmatic processes represented by partial melting and fractional crystallization.Integration of whole-rock chemical composition and mineral microanalysis suggests that felsic magmatism in the west Wadi El Gemal area produced voluminous masses of syn-to post-collisional granite,pegmatite,and aplite.An evolutionary three-stage model is presented to understand late magmatism in the ANS in terms of a geodynamic model.Such a model discusses the propagation of felsic magmatism in the ANS during syn-collisional to post-collisional stages.展开更多
The late Carboniferous to early Permian period is renowned for extensive coal formation and frequent paleowildfires.Nonetheless,the nature and distribution of these wildfires varied significantly over time.In an effor...The late Carboniferous to early Permian period is renowned for extensive coal formation and frequent paleowildfires.Nonetheless,the nature and distribution of these wildfires varied significantly over time.In an effort to elucidate the patterns of paleowildfires during the late Paleozoic Ice Age and to probe into the controlling mechanisms of paleowildfires under icehouse conditions,a comprehensive analysis was performed on coal samples from the Taiyuan and Shanxi formations within the Dacheng coalfield of Hebei Province,North China.The dataset was augmented with global inertinite data from the late Carboniferous to early Permian periods and was compared to paleowildfire patterns from the Pliocene to Holocene epochs.The results show that paleowildfires in the Dacheng coalfield of North China transitioned from moderate-scale,low-intensity surface fires to large-scale,relatively high-intensity ground fires.Globally,the distribution of paleowildfires shifted from Euramerica to Gondwana,Cathaysia,and Angara from 300 Ma to 290 Ma,accompanied by a corresponding increase in inertinite content.This spatial and temporal variation in wildfire activity appears to have been strongly influenced by paleoclimate and atmospheric conditions.At 300 Ma,cooler and wetter paleoclimate,coupled with relatively low atmospheric pO_(2) levels,likely contributed to a reduced incidence of paleowildfires.In contrast,at 290 Ma,warmer paleoclimate,higher atmospheric pO_(2) levels,and the flourishing mires in Gondwana,Cathaysia,and Angara were conducive to more intense paleowildfires.This pattern is further supported by the comparison to more recent icehouse periods.Similar to the late Carboniferous–early Permian period,wildfire activity increased from the Pliocene to the Holocene,highlighting the critical role of climatic conditions in driving wildfire proliferation under icehouse conditions.However,the Pleistocene to Holocene wildfires were less intense than those of the late Carboniferous–early Permian,suggesting that atmospheric oxygen concentrations played a key role in modulating the evolution of the fire systems over geological timescales.These findings underscore the complex interplay between climate,atmospheric composition,and vegetation in shaping wildfire dynamics across Earth’s history.展开更多
The Cretaceous Koum Basin is a rift-related half-graben in northern Cameroon,which constitutes a portion of the Yola Arm of the Upper Benue Trough.This study presents the first comprehensive dataset combining mineral-...The Cretaceous Koum Basin is a rift-related half-graben in northern Cameroon,which constitutes a portion of the Yola Arm of the Upper Benue Trough.This study presents the first comprehensive dataset combining mineral-ogical,bulk-rock geochemical,and stable C-H-O isotopic data for dark-gray,finegrained mudstones from the basin,providing new insights into its sediment source,paleoenvironment,and geodynamic setting.The mudstones primarily consist of phyllosilicates(~8.6%),feldspars(~30.5%),carbonates(~13.7%),and minor iron oxides(~2.7%),with vermiculite,illite,and kaolinite as the main clay minerals.The presence of analcime,ankerite,and dolomite suggests low-grade metamorphism and/or hydrothermal alteration.Fe_(2)O_(3)/K_(2)O(1.52-6.40)and SiO_(2)/Al_(2)O_(3)(2.97-4.68)ratios classify the mudstones as compositionally immature shales(ICV~1.64)with low-moderate chemical weathering(CIA~56.35;PIA~59.74;R^(3+)/R^(3+)+R^(2+)+M^(+)~0.51).Trace element ratios(Th/Sc~1.70,Zr/Sc~1.33,La/Sc~6.30,La/Th~4.14)indicate an intermediate igneous provenance from a continental crustal source.Paleoenviron-mental proxies suggest deposition in a dynamic basin environment marked by fluctuating redox(C org/P:0.21-178.34)and salinity(Sr/Ba:0.34-3.25;N-values:48-35.92)conditions,ranging from oxic to anoxic and brackish to saline.Major element data(SiO_(2) vs.Al_(2)O_(3)+K_(2)O+Na_(2)O)indicate a semi-arid regime,while Paleoclimatic indicators such as Sr/Cu(1.88-37.47)and C-values(0.12-0.93)suggests alter-nating humid and arid conditions.Notably,stable isotope data,reported here for the first time in the Koum Basin,reveal a predominantly terrestrial,fluvial-deltaic C_(3) plant source for organic carbon(δ^(13)C-25.2‰ to -35.2‰)and complex fluid-rock interactions involving meteoric and magmatic-metamorphic fluids under a warm,equatorial climate(δ^(18)O+3.6‰to +24.9‰,δ^(2)H-104‰ to-50‰).The combined mineralogical,geochemical,and isotopic data point to deposition in a tectonically active continental arc setting,with contributions from ocean island arc and passive margin sources.展开更多
Geological storage and utilization of CO_(2)involve complex interactions among Thermo-hydromechanical-chemical(THMC)coupling processes,which significantly affect storage integrity and efficiency.To address the challen...Geological storage and utilization of CO_(2)involve complex interactions among Thermo-hydromechanical-chemical(THMC)coupling processes,which significantly affect storage integrity and efficiency.To address the challenges in accurately simulating these coupled phenomena,this paper systematically reviews recent advances in the mathematical modeling and numerical solution of THMC coupling in CO_(2)geological storage.The study focuses on the derivation and structure of governing and constitutive equations,the classification and comparative performance of fully coupled,iteratively coupled,and explicitly coupled solution methods,and the modeling of dynamic changes in porosity,permeability,and fracture evolution induced by multi-field interactions.Furthermore,the paper evaluates the capabilities,application scenarios,and limitations of major simulation platforms,including TOUGH,CMG-GEM,and COMSOL.By establishing a comparative framework integrating model formulations and solver strategies,this work clarifies the strengths and gaps of current approaches and contributes to the development of robust,scalable,and mechanism-oriented numerical models for long-term prediction of CO_(2)behavior in geological formations.展开更多
This research investigates dynamic earth processes within the South Setifian allochthonous ensemble,providing insights into landscape evolution and seismotectonic activity within the Tellian mountain chain.Focusing on...This research investigates dynamic earth processes within the South Setifian allochthonous ensemble,providing insights into landscape evolution and seismotectonic activity within the Tellian mountain chain.Focusing on the Jebel Gustar and Kef Lahmar area,which includes 14 sub-basins,this research uses a DEM-based technique to assess Holocene activities,lineament characteristics,and stream systems.Five geomorphic indices are used to assess relative active tectonics:the stream lengthgradient index(SL),drainage basin asymmetry(AF),valley-floor width to valley height ratio(VF),drainage basin shape(BS),and mountain front sinuosity(SMF).A weighted overlay of these five indices produces the Index of Relative Active Tectonics(IRAT)map.The findings reveal significant neotectonic activity in the study area,supported by profound basement faulting.This research highlights the morpho-structural processes and neotectonics activity in the Jebel Gustar,providing a framework for investigating the evolution of this structure.Additionally,it enhances comprehension of the interactions between the alpine range's internal zones in Eastern Algeria and the Atlasic domain.This study proposes a systematic approach to evaluate the tectonic and geomorphological dynamics of the South Setif region.展开更多
Deposition of fluvial sandbodies is controlled mainly by characteristics of the system, such as the rate of avulsion and aggradation of the fluvial channels and their geometry. The impact and the interaction of these ...Deposition of fluvial sandbodies is controlled mainly by characteristics of the system, such as the rate of avulsion and aggradation of the fluvial channels and their geometry. The impact and the interaction of these parameters have not received adequate attention. In this paper, the impact of geological uncertainty resulting from the interpretation of the fluvial geometry, maximum depth of channels, and their avulsion rates on primary production is studied for fluvial reservoirs. Several meandering reservoirs were generated using a process-mimicking package by varying several con- trolling factors. Simulation results indicate that geometrical parameters of the fluvial channels impact cumulative pro- duction during primary production more significantly than their avulsion rate. The most significant factor appears to be the maximum depth of fluvial channels. The overall net-to-gross ratio is closely correlated with the cumulative oil production of the field, but cumulative production values for individual wells do not appear to be correlated with the local net-to-gross ratio calculated in the vicinity of each well. Connectedness of the sandbodies to each well, defined based on the minimum time-of-flight from each block to the well, appears to be a more reliable indicator of well-scale production.展开更多
Magmatic periodicity is recognized in continental arcs worldwide,but the mechanism responsible for punctuated arc magmatism is controversial.Continental arcs in the Trans-Himalayan orogenic system display episodic mag...Magmatic periodicity is recognized in continental arcs worldwide,but the mechanism responsible for punctuated arc magmatism is controversial.Continental arcs in the Trans-Himalayan orogenic system display episodic magmatism and the most voluminous flare-up in this system was in early Eocene during the transition from subduction to collision.The close association of the flare-up with collision is intriguing.Our study employs zircon Lu-Hf and bulk rock Sr-Nd isotopes,along with mineral geochemistry,to track the melt sources of the Nymo intrusive complex and the role of mantle magma during the early Eocene flare-up of the Gangdese arc,Xizang.The Nymo intrusive complex is composed of gabbronorite,diorite,quartz diorite,and granodiorite which define an arc-related calc-alkaline suite.Zircon U-Pb ages reveal that the complex was emplaced between~50–47 Ma.Zircon Hf isotopes yieldεHf(t)values of 8.2–13.1,while whole-rock Sr and Nd isotopes yieldεNd(t)values of 2.7–6.5 indicative of magmatism dominated by melting of a juvenile mantle source with only minor crustal assimilation(~15%–25%)as indicated by assimilation and fractional crystallization modeling.Together with published data,the early Eocene magmatic flare-up was likely triggered by slab breakoff of subducted oceanic lithosphere at depths shallower than the overriding plate.The early Eocene magmatic flare-up may have contributed to crustal thickening of the Gangdese arc.This study provides important insights into the magmatic flare-up and its significant role in the generation of large batholiths during the transition from subduction to collision.展开更多
When early explorers first crossed the Platte River in what is now Nebraska (USA), it was said the river was “a mile wide and an inch deep”(Mokler, 1923;Smith, 1971). This phrase was used to describe not only the di...When early explorers first crossed the Platte River in what is now Nebraska (USA), it was said the river was “a mile wide and an inch deep”(Mokler, 1923;Smith, 1971). This phrase was used to describe not only the difficulty in crossing the river but also in navigating its length. The trouble with a river being too wide is the risk that it won’t provide the depth necessary to be useful. The same thing can be said of multidisciplinary scientific journals. While a journal can claim to be multidisciplinary, there is a risk of it being so broad that its articles can only engage the reader at a superficial level. Nothing could be further from the truth with Geoscience Frontiers. Over the past ten years, this journal has successfully navigated the wide breadth of geoscience while providing a level of depth and detail that rivals discipline-specific journals.展开更多
In this study,we aim to assess dynamical downscaling simulations by utilizing a novel bias-corrected global climate model(GCM)data to drive a regional climate model(RCM)over the Asia-western North Pacific region.Three...In this study,we aim to assess dynamical downscaling simulations by utilizing a novel bias-corrected global climate model(GCM)data to drive a regional climate model(RCM)over the Asia-western North Pacific region.Three simulations were conducted with a 25-km grid spacing for the period 1980–2014.The first simulation(WRF_ERA5)was driven by the European Centre for Medium-Range Weather Forecasts Reanalysis 5(ERA5)dataset and served as the validation dataset.The original GCM dataset(MPI-ESM1-2-HR model)was used to drive the second simulation(WRF_GCM),while the third simulation(WRF_GCMbc)was driven by the bias-corrected GCM dataset.The bias-corrected GCM data has an ERA5-based mean and interannual variance and long-term trends derived from the ensemble mean of 18 CMIP6 models.Results demonstrate that the WRF_GCMbc significantly reduced the root-mean-square errors(RMSEs)of the climatological mean of downscaled variables,including temperature,precipitation,snow,wind,relative humidity,and planetary boundary layer height by 50%–90%compared to the WRF_GCM.Similarly,the RMSEs of interannual-tointerdecadal variances of downscaled variables were reduced by 30%–60%.Furthermore,the WRF_GCMbc better captured the annual cycle of the monsoon circulation and intraseasonal and day-to-day variabilities.The leading empirical orthogonal function(EOF)shows a monopole precipitation mode in the WRF_GCM.In contrast,the WRF_GCMbc successfully reproduced the observed tri-pole mode of summer precipitation over eastern China.This improvement could be attributed to a better-simulated location of the western North Pacific subtropical high in the WRF_GCMbc after GCM bias correction.展开更多
Based on detailed geological and geomorphological mapping, sampling and micro-palaeontological determinations, both of the alpine and neogene formations, new data have been derived for Spetses Island (SW Aegean). The ...Based on detailed geological and geomorphological mapping, sampling and micro-palaeontological determinations, both of the alpine and neogene formations, new data have been derived for Spetses Island (SW Aegean). The applied methodology provided results on the paleogeographic evolution for Spetses Island and the nearby land of Argolida peninsula as well. Based mainly on characteristic nannofossils, a Miocene age of the post-alpine formations is determined. It is the first time that miocene formations have been identified, not only in Spetses Island and Argolida, but in the whole area of Peloponnesus, where only Plio-pleistocene deposits have been described. This work also leads to the conclusion that Spetses Island is attached to the Argolida peninsula, forming an independent paleogeographic unit since Upper Miocene.展开更多
The purpose of this paper is to evaluate control of orientation of foliations and joints on the direction of valley axes in the Stribrne Hory area in the Bohemian-Moravian Highlands in central part of the Czech Republ...The purpose of this paper is to evaluate control of orientation of foliations and joints on the direction of valley axes in the Stribrne Hory area in the Bohemian-Moravian Highlands in central part of the Czech Republic. This area is predominantly built by metamorphic rocks. It is situated near the Pribyslav deep-seated fault. The data concerning of foliations, joints and valley axes were statistically analyzed and then visually compared according to their distribution using direction roses. Directions of valley axes have generally orientation of NNE-SSW, SE, E-W, NW and WNW and coincide with the system of foliations and ordinarily steep joints.展开更多
The world is at a critical state of limited resources,growing population,and increasing hazard potential.In the near future,geoscientists will be sought to solve these worldwide woes or face the consequences of a dema...The world is at a critical state of limited resources,growing population,and increasing hazard potential.In the near future,geoscientists will be sought to solve these worldwide woes or face the consequences of a demanding public.Cheap,innovative technology and collaboration among several disciplines are needed to proceed forward and solve the difficult questions that humanity as a whole faces.Years of advances and dilemmas in earthquake prediction highlight a theme that stretches through all of geoscience and society:the need for quick solutions to pressing global concerns.展开更多
The Wadi Natash volcanic field(WNVF)in the south of the Eastern Desert of Egypt is a typical example of well-preserved intraplate alkaline magmatism during the Late Cretaceous,i.e.,prior to the Oligo-Miocene Red Sea r...The Wadi Natash volcanic field(WNVF)in the south of the Eastern Desert of Egypt is a typical example of well-preserved intraplate alkaline magmatism during the Late Cretaceous,i.e.,prior to the Oligo-Miocene Red Sea rift.We compiled stratigraphic sections at two sectors;namely East Gabal Nuqra and West Khashm Natash(WKN)where the volcanic flows are intercalated with the Turonian Abu Agag sandstone with occasional paleosols when volcanic activity is intermittent.Peridotite mantle xenoliths are encountered in the first sector whereas flows in the second sector are interrupted by trachyte plugs and ring dykes.On a geochemical basis,the maifc melt originating from the lithospheric mantle beneath the WNVF practiced~5%partial melting of phlogopite-bearing garnet peridotite.Basalts dominate in the two sectors and highly evolved(silicic)rocks are confined to the WKN sector.Rejuvenation of ancient Precambrian fractures following the NW-SE and ENE-WSW trends facilitated the ascend of Late Cretaceous mantle-derived alkaline magma.Structurally,the WNVF developed at the eastern shoulder of the so-called"Kom Ombo-Nuqra-Kharit rift system"that represents a well-defined NW-trending intracontinental rift basin in the southern Eastern Desert.In such a structural setup,the Natash volcanic are confined to half-grabens at the East Gabal Nuqra sector whereas the West Khashm Natash sector is subjected to extensional stresses that propagated eastwards.The WNVF is a typical example of fluvial clastics(Turonian)intercalation with rift-related alkaline volcanic rocks in northeast Africa.展开更多
Neoproterozoic island arc assemblage of the Arabian–Nubian Shield(ANS)in the Eastern Desert(ED)of Egypt comprises juvenile suites of metavolcanics(MV),large amounts of meta-sedimentary rocks(MS),and voluminous metaga...Neoproterozoic island arc assemblage of the Arabian–Nubian Shield(ANS)in the Eastern Desert(ED)of Egypt comprises juvenile suites of metavolcanics(MV),large amounts of meta-sedimentary rocks(MS),and voluminous metagabbros-diorites(MGD)and syn-tectonic intrusions of older granitoids(OG).We report here the updates of these four rock units in terms of classification,distribution,chemical characteristics,geodynamic evolution,metamorphism,and ages.In addition,we discuss these integrated data to elucidate a reasonable and reliable model for crustal evolution in the ANS.The main features of these rock units indicate their relation to each other and the geodynamic environment dominated by early immature oceanic island arcs to primitive continental arcs.Integrated information of the island arc metavolcanic and plutonic rocks(gabbros,diorites,tonalites,and granodiorites)furnish evidence of the genetic relationships.These include proximity and a coeval nature in the field;all protolith magmas are subalkaline in nature following calc-alkaline series with minor tholeiitic affinities;common geochemical signature of the arc rocks and subduction-related magmatism;their similar enrichment in LREEs;and similar major element compositions with mafic melts derived from metasomatized mantle wedge.The volcano-sedimentary and the OG rocks underwent multiphase deformation events whereas the MGD complexes deformed slightly.Based on the magmatic,sedimentological,and metamorphic evolutions constrained by geochronological data as well as the progressive evolutionary trend from extensional to compressional regimes,a possible gradual decrease in the subducted slab dip angle is the most infl uential in any geodynamic model for arc assemblage in the ED of Egypt.展开更多
Opencast coal mining produces trash of soil and rock containing various minerals,that are usually dumped nearby the abandoned sites which causes severe environmental concern including the production of acid mine drain...Opencast coal mining produces trash of soil and rock containing various minerals,that are usually dumped nearby the abandoned sites which causes severe environmental concern including the production of acid mine drainage(AMD)through oxidation pyrite minerals.The current study entailed assessing the potential production of AMD from an opencast coal mining region in Northeast part of India.In order to have a comprehensive overview of the AMD problem in Makum coalfield,the physico-chemical,geochemical,and petrological characteristics of the coal and overburden(OB)samples collected from the Makum coalfield(Northeast India)were thoroughly investigated.The maceral compositions reveal that coal features all three groups of macerals(liptinite,vitrinite,and inertinite),with a high concentration of liptinite indicating the coal of perhydrous,thereby rendering it more reactive.Pyrite(FeS_(2))oxidation kinetics were studied by conducting the aqueous leaching experiments of coal and(OB)samples to interpret the chemical weathering under controlled laboratory conditions of various temperature and time periods,and to replicate the actual mine site leaching.Inductively coupled plasma-optical emission spectroscopy(ICP-OES)was operated to detect the disposal of some precarious elements from coal and OB samples to the leachates during our controlled leaching experiment.The Rare earth element(REE)enrichment in the samples shows the anthropogenic incorporation of the REE in the coal and OB.These experiments reveal the change in conductivity,acid producing tendency,total dissolved solid(TDS),total Iron(Fe)and dissolved Sulfate(SO_(4)^(2−))ions on progress of the leaching experiments.Moreover,the discharge of FeS_(2) via atmospheric oxidation in laboratory condition undergoes a significant growth with the rise of temperature of the reaction systems in the environment and follows pseudo first order kinetics.A bio-remediative strategies is also reported in this paper to mitigate AMD water by employing size-segregated powdered limestone and water hyacinth plant in an indigenously developed site-specific prototype station.Apart from neutralisation of AMD water,this eco-friendly AMD remediation strategy demonstrates a reduction in PHEs concentrations in the treated AMD water.展开更多
The volatility of water resources is increasing owing to climate change,and various developments are being undertaken for a stable supply of water resources.Among the many available water resources,groundwater is attr...The volatility of water resources is increasing owing to climate change,and various developments are being undertaken for a stable supply of water resources.Among the many available water resources,groundwater is attracting attention as one of the country’s most important resources in Korea.This study developed a groundwater potential map(GPM)for the exploration of groundwater in the Geumgang River basin,one of the four major river basins in Korea.This consisted of ten thematic layers(hydrogeology,fractured zone,depth to groundwater level,distance to surface water,lineament density,slope,stream drainage density,soil drainage,land cover,and annual rainfall)of remotely sensed data and satellite images to explore a wide range of areas.Each thematic layer was weighted through Analytical Hierarchal Process and Technique for Order Preference by Similarity to Ideal Solution,and the groundwater potential was determined.The final GPM are classified into five categories:very high,high,moderate,low,and very low.To verify the GPM,specific capacity data from a total of 2,671 wells was used.The GPM in this study make groundwater to be considered as promising and feasible alternative resource to surface water in case of future climate crisis such as heavy drought.展开更多
Five sequences of deep fluid injections at the Pohang Enhanced Geothermal System(EGS)triggered an ML 5.4 earthquake on November 15,2017.The foreshock-mainshock-aftershock sequence was monitored using dense seismic net...Five sequences of deep fluid injections at the Pohang Enhanced Geothermal System(EGS)triggered an ML 5.4 earthquake on November 15,2017.The foreshock-mainshock-aftershock sequence was monitored using dense seismic networks.Between November 14,2017,and May 31,2023,this study detected 5,169 earthquakes and determined the relative locations of 4,902 earthquakes,including seven foreshocks.A heterogeneous subsurface fault model is proposed,in which the fault is reactivated by induced and triggered earthquakes.The earthquake frequency decreased after the mainshock,with a temporary increase after the ML 4.6 event on February 10,2018.The magnitude-frequency b-values are significantly lower than those for the background seismicity in the Korean Peninsula and those for the 2016 Gyeongju earthquake sequence.The aftershock decay rate p-values are within the range of typical values,regardless of decreasing over time.The earthquake focal mechanisms exhibit a predominance of strike-slip components,whereas the slip tendency indicates a higher value in reverse faulting geometry,implying stress redistribution after the mainshock.The seismic landscape with ongoing aftershock activity after the 2017 Pohang earthquake underscores the importance of sustained,long-term seismic monitoring to comprehensively grasp the implications of the new seismic environment for seismic hazards in the area.展开更多
For the Anthropocene to get recognized as a real geological era,first and foremost its strata must be identified.Several geological formations such as bogs,lakebeds,reefs,ice sheets,speleothems,river estuary deposits,...For the Anthropocene to get recognized as a real geological era,first and foremost its strata must be identified.Several geological formations such as bogs,lakebeds,reefs,ice sheets,speleothems,river estuary deposits,and sea floors have been considered as potential candidates for the Anthropocene strata.This consideration arises from the emergence of novel materials associated with the Anthropocene,including radioactive isotopes,plastics,and aluminum,started to be discovered in their sediments and dramatically increased since the mid-20th century.Yet,these deposits are no longer considered‘natural’because human activities are largely controlling the transport and depositional processes from source to sink.The Municipal Solid Waste(MSW)in landfills has been also‘unnaturally’transported and deposited(landfilled)by humans.Since the 1950s,the controlled landfills have been made worldwide,and thus the opening time of the landfills is clear.The MSW layers of landfills,which appeared globally,contemporaneously,and with distinct characteristics,are indeed the‘artificial(anthropogenic)’strata showing a new and clear aspect of human influence,unprecedented in geological time.The MSW layers can be considered valuable indicators of the Anthropocene era because they not only preserve the history of human life but also sensitively demonstrate the scale of human activities like mass production,consumption,and disposal.The MSW layers can be expected to serve as a unique window into the Anthropocene.展开更多
The Anthropocene as a prospective new,ongoing series/epoch must be defensible against all relevant concerns.We address the seven,still-relevant challenges posed to the Anthropocene Working Group by the Chair,Internati...The Anthropocene as a prospective new,ongoing series/epoch must be defensible against all relevant concerns.We address the seven,still-relevant challenges posed to the Anthropocene Working Group by the Chair,International Commission on Stratigraphy(ICS),in 2014.(1)Concept or reality?The Anthropocene possesses a substantial,sharply distinctive stratigraphic record recognisable through many proxy signals from the mid-20th century onwards;(2)GSSP or GSSA?The Anthropocene can be defined by a GSSP and correlated globally;(3)Past or future?The Anthropocene unquestionably represents geological time,its transformations having already moved the Earth System beyond Holocene norms towards an irreversible future trajectory;(4)Utility?The Anthropocene’s distinctive material content allows useful delineation on geological sections/maps;(5)Indelibility?Many of the Anthropocene’s transformative effects cannot be subsequently effaced or overprinted;(6)Fit within the Geological Time Scale(GTS)?The Anthropocene represents a unique,youngest,interval in Earth history and strata of profound significance;(7)What is its value?The chronostratigraphic Anthropocene has conceptual usefulness even informally,but would then lack the clarity,stability and recognition that formalization provides.Without its formalization,the GTS would no longer accurately reflect Earth history,diminishing the relevance of geological science for analysis of ongoing planetary change.展开更多
基金supported by grants from the National Science Foundation of the USA.
文摘East Asian continental tectonics challenges the plate tectonics paradigm with its diffuse intraplate deformation,magmatism,and earthquakes.Despite extensive studies,fundamental questions persist.This review examines ten critical questions of East Asian tectonics,including the thickness of the continental lithosphere,the origin of the North–South Gravity Lineament,and the northern extent of the Indian plate beneath the Tibetan Plateau.Additional questions address the Tibetan Plateau's lateral growth,the Tianshan mountain building,the mantle flow in response to the Indo-Asian collision,and the formation of the Shanxi Rift.The review also explores the subduction along the eastern margins of the East Asian Continent and the origins of the Changbaishan volcanic field,the destruction of the North China Craton,and the development of the Mesozoic Large Granitic Province in South China.Originally presented at the DEEP2024 workshop to stimulate discussion of how SinoProbe-II research initiatives could advance our understanding of Asian tectonics,this review provides context for each question,summarizes current knowledge,and identifies promising research directions.
基金finational supported by the Foundation of Science,Technology and Innovation Funding Authority(STDF)(Award Number:47106Recipient:Mokhles K K.Azer)。
文摘Leucogranite,pegmatite,and aplite from selected areas in the Wadi El Gemal area in the southern Eastern Desert of Egypt were investigated geochemically for their petrogenesis.These rocks represent a significant episode of felsic magmatism during the late stage of the Pan-African orogeny in the evolution of the Arabian–Nubian Shield(ANS)during the Late Neoproterozoic.On a petrographic basis,the leucogranite is sometimes garnetiferous and can be distinguished into monzogranite,syenogranite,and alkali feldspar granite.The analyses of muscovite,biotite,garnet,and apatite reveal the magmatic nature of the studied leucogranite.The investigated leucogranite,pegmatite,and aplite are alkali-calcic,calc-alkaline,and peraluminous.The peraluminous nature of these rocks is evidenced by using the chemical analyses of biotite.These studied rocks show a slight enrichment in light rare-earth elements(LREEs)and large-ion lithophile elements(LILE,especially Rb and Th),with an insignificant depletion of heavy rareearth elements(HREEs).On a geochemical basis,the leucogranite,pegmatite,and aplite in the study area crystallized from multiple-sourced melts that include mafic,metagraywake,and pelitic.They were derived from melts generated at crystallization temperatures around 568-900℃ for leucogranite,553-781℃ for pegmatite,and 639-779℃ for aplite based on the Zr saturation geothermometers,and at a pressure around 0.39-0.48 GPa,i.e.shallow depth intrusions.The studied felsic rocks have strong negative Eu anomalies,which are very consistent with an upper crust composition,indicating fractionation of feldspar cumulates.Also,they show a moderate La/Sm ratio indicating combined magmatic processes represented by partial melting and fractional crystallization.Integration of whole-rock chemical composition and mineral microanalysis suggests that felsic magmatism in the west Wadi El Gemal area produced voluminous masses of syn-to post-collisional granite,pegmatite,and aplite.An evolutionary three-stage model is presented to understand late magmatism in the ANS in terms of a geodynamic model.Such a model discusses the propagation of felsic magmatism in the ANS during syn-collisional to post-collisional stages.
基金supported by the National Natural Science Foundation of China(Grant No.42302205 and No.42002128)the Fundamental Research Funding Project of Liaoning Education Department(Grant No.LJKMZ20220692)the Open Fund of State Key Laboratory of Coal Resources and Safe Mining(Grant No.SKLCRSM22KFA07 and No.SKLCRSM20KFA02).
文摘The late Carboniferous to early Permian period is renowned for extensive coal formation and frequent paleowildfires.Nonetheless,the nature and distribution of these wildfires varied significantly over time.In an effort to elucidate the patterns of paleowildfires during the late Paleozoic Ice Age and to probe into the controlling mechanisms of paleowildfires under icehouse conditions,a comprehensive analysis was performed on coal samples from the Taiyuan and Shanxi formations within the Dacheng coalfield of Hebei Province,North China.The dataset was augmented with global inertinite data from the late Carboniferous to early Permian periods and was compared to paleowildfire patterns from the Pliocene to Holocene epochs.The results show that paleowildfires in the Dacheng coalfield of North China transitioned from moderate-scale,low-intensity surface fires to large-scale,relatively high-intensity ground fires.Globally,the distribution of paleowildfires shifted from Euramerica to Gondwana,Cathaysia,and Angara from 300 Ma to 290 Ma,accompanied by a corresponding increase in inertinite content.This spatial and temporal variation in wildfire activity appears to have been strongly influenced by paleoclimate and atmospheric conditions.At 300 Ma,cooler and wetter paleoclimate,coupled with relatively low atmospheric pO_(2) levels,likely contributed to a reduced incidence of paleowildfires.In contrast,at 290 Ma,warmer paleoclimate,higher atmospheric pO_(2) levels,and the flourishing mires in Gondwana,Cathaysia,and Angara were conducive to more intense paleowildfires.This pattern is further supported by the comparison to more recent icehouse periods.Similar to the late Carboniferous–early Permian period,wildfire activity increased from the Pliocene to the Holocene,highlighting the critical role of climatic conditions in driving wildfire proliferation under icehouse conditions.However,the Pleistocene to Holocene wildfires were less intense than those of the late Carboniferous–early Permian,suggesting that atmospheric oxygen concentrations played a key role in modulating the evolution of the fire systems over geological timescales.These findings underscore the complex interplay between climate,atmospheric composition,and vegetation in shaping wildfire dynamics across Earth’s history.
文摘The Cretaceous Koum Basin is a rift-related half-graben in northern Cameroon,which constitutes a portion of the Yola Arm of the Upper Benue Trough.This study presents the first comprehensive dataset combining mineral-ogical,bulk-rock geochemical,and stable C-H-O isotopic data for dark-gray,finegrained mudstones from the basin,providing new insights into its sediment source,paleoenvironment,and geodynamic setting.The mudstones primarily consist of phyllosilicates(~8.6%),feldspars(~30.5%),carbonates(~13.7%),and minor iron oxides(~2.7%),with vermiculite,illite,and kaolinite as the main clay minerals.The presence of analcime,ankerite,and dolomite suggests low-grade metamorphism and/or hydrothermal alteration.Fe_(2)O_(3)/K_(2)O(1.52-6.40)and SiO_(2)/Al_(2)O_(3)(2.97-4.68)ratios classify the mudstones as compositionally immature shales(ICV~1.64)with low-moderate chemical weathering(CIA~56.35;PIA~59.74;R^(3+)/R^(3+)+R^(2+)+M^(+)~0.51).Trace element ratios(Th/Sc~1.70,Zr/Sc~1.33,La/Sc~6.30,La/Th~4.14)indicate an intermediate igneous provenance from a continental crustal source.Paleoenviron-mental proxies suggest deposition in a dynamic basin environment marked by fluctuating redox(C org/P:0.21-178.34)and salinity(Sr/Ba:0.34-3.25;N-values:48-35.92)conditions,ranging from oxic to anoxic and brackish to saline.Major element data(SiO_(2) vs.Al_(2)O_(3)+K_(2)O+Na_(2)O)indicate a semi-arid regime,while Paleoclimatic indicators such as Sr/Cu(1.88-37.47)and C-values(0.12-0.93)suggests alter-nating humid and arid conditions.Notably,stable isotope data,reported here for the first time in the Koum Basin,reveal a predominantly terrestrial,fluvial-deltaic C_(3) plant source for organic carbon(δ^(13)C-25.2‰ to -35.2‰)and complex fluid-rock interactions involving meteoric and magmatic-metamorphic fluids under a warm,equatorial climate(δ^(18)O+3.6‰to +24.9‰,δ^(2)H-104‰ to-50‰).The combined mineralogical,geochemical,and isotopic data point to deposition in a tectonically active continental arc setting,with contributions from ocean island arc and passive margin sources.
基金supported by the China Postdoctoral Science Foundation(No.2024M752803)the National Natural Science Foundation of China(No.52179112)the Open Fund of National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University)(No.PLN2023-02)。
文摘Geological storage and utilization of CO_(2)involve complex interactions among Thermo-hydromechanical-chemical(THMC)coupling processes,which significantly affect storage integrity and efficiency.To address the challenges in accurately simulating these coupled phenomena,this paper systematically reviews recent advances in the mathematical modeling and numerical solution of THMC coupling in CO_(2)geological storage.The study focuses on the derivation and structure of governing and constitutive equations,the classification and comparative performance of fully coupled,iteratively coupled,and explicitly coupled solution methods,and the modeling of dynamic changes in porosity,permeability,and fracture evolution induced by multi-field interactions.Furthermore,the paper evaluates the capabilities,application scenarios,and limitations of major simulation platforms,including TOUGH,CMG-GEM,and COMSOL.By establishing a comparative framework integrating model formulations and solver strategies,this work clarifies the strengths and gaps of current approaches and contributes to the development of robust,scalable,and mechanism-oriented numerical models for long-term prediction of CO_(2)behavior in geological formations.
文摘This research investigates dynamic earth processes within the South Setifian allochthonous ensemble,providing insights into landscape evolution and seismotectonic activity within the Tellian mountain chain.Focusing on the Jebel Gustar and Kef Lahmar area,which includes 14 sub-basins,this research uses a DEM-based technique to assess Holocene activities,lineament characteristics,and stream systems.Five geomorphic indices are used to assess relative active tectonics:the stream lengthgradient index(SL),drainage basin asymmetry(AF),valley-floor width to valley height ratio(VF),drainage basin shape(BS),and mountain front sinuosity(SMF).A weighted overlay of these five indices produces the Index of Relative Active Tectonics(IRAT)map.The findings reveal significant neotectonic activity in the study area,supported by profound basement faulting.This research highlights the morpho-structural processes and neotectonics activity in the Jebel Gustar,providing a framework for investigating the evolution of this structure.Additionally,it enhances comprehension of the interactions between the alpine range's internal zones in Eastern Algeria and the Atlasic domain.This study proposes a systematic approach to evaluate the tectonic and geomorphological dynamics of the South Setif region.
文摘Deposition of fluvial sandbodies is controlled mainly by characteristics of the system, such as the rate of avulsion and aggradation of the fluvial channels and their geometry. The impact and the interaction of these parameters have not received adequate attention. In this paper, the impact of geological uncertainty resulting from the interpretation of the fluvial geometry, maximum depth of channels, and their avulsion rates on primary production is studied for fluvial reservoirs. Several meandering reservoirs were generated using a process-mimicking package by varying several con- trolling factors. Simulation results indicate that geometrical parameters of the fluvial channels impact cumulative pro- duction during primary production more significantly than their avulsion rate. The most significant factor appears to be the maximum depth of fluvial channels. The overall net-to-gross ratio is closely correlated with the cumulative oil production of the field, but cumulative production values for individual wells do not appear to be correlated with the local net-to-gross ratio calculated in the vicinity of each well. Connectedness of the sandbodies to each well, defined based on the minimum time-of-flight from each block to the well, appears to be a more reliable indicator of well-scale production.
基金co-supported by the National Natural Science Foundation of China(Grant No.42272267)the Research Grants of Chinese Academy of Geological Sciences(Grant No.JKYQN202309)+3 种基金the National Key Research and Development Project"Key scientific issues of transformative technology"(Grant No.2019YFA0708604)the second Tibetan Plateau Scientific Expedition and Research Program(STEP)Grant(Grant Nos.2019QZKK0802,2019QZKK0901)the Scientific Investigation on Basic Resources of Ministry of Science and Technology(Grant No.2021FY100101)the Geological Survey of China(Grant Nos.DD20221630,DD20242126)。
文摘Magmatic periodicity is recognized in continental arcs worldwide,but the mechanism responsible for punctuated arc magmatism is controversial.Continental arcs in the Trans-Himalayan orogenic system display episodic magmatism and the most voluminous flare-up in this system was in early Eocene during the transition from subduction to collision.The close association of the flare-up with collision is intriguing.Our study employs zircon Lu-Hf and bulk rock Sr-Nd isotopes,along with mineral geochemistry,to track the melt sources of the Nymo intrusive complex and the role of mantle magma during the early Eocene flare-up of the Gangdese arc,Xizang.The Nymo intrusive complex is composed of gabbronorite,diorite,quartz diorite,and granodiorite which define an arc-related calc-alkaline suite.Zircon U-Pb ages reveal that the complex was emplaced between~50–47 Ma.Zircon Hf isotopes yieldεHf(t)values of 8.2–13.1,while whole-rock Sr and Nd isotopes yieldεNd(t)values of 2.7–6.5 indicative of magmatism dominated by melting of a juvenile mantle source with only minor crustal assimilation(~15%–25%)as indicated by assimilation and fractional crystallization modeling.Together with published data,the early Eocene magmatic flare-up was likely triggered by slab breakoff of subducted oceanic lithosphere at depths shallower than the overriding plate.The early Eocene magmatic flare-up may have contributed to crustal thickening of the Gangdese arc.This study provides important insights into the magmatic flare-up and its significant role in the generation of large batholiths during the transition from subduction to collision.
文摘When early explorers first crossed the Platte River in what is now Nebraska (USA), it was said the river was “a mile wide and an inch deep”(Mokler, 1923;Smith, 1971). This phrase was used to describe not only the difficulty in crossing the river but also in navigating its length. The trouble with a river being too wide is the risk that it won’t provide the depth necessary to be useful. The same thing can be said of multidisciplinary scientific journals. While a journal can claim to be multidisciplinary, there is a risk of it being so broad that its articles can only engage the reader at a superficial level. Nothing could be further from the truth with Geoscience Frontiers. Over the past ten years, this journal has successfully navigated the wide breadth of geoscience while providing a level of depth and detail that rivals discipline-specific journals.
基金supported jointly by the National Natural Science Foundation of China (Grant No.42075170)the National Key Research and Development Program of China (2022YFF0802503)+2 种基金the Jiangsu Collaborative Innovation Center for Climate Changea Chinese University Direct Grant(Grant No. 4053331)supported by the National Key Scientific and Technological Infrastructure project“Earth System Numerical Simulator Facility”(EarthLab)
文摘In this study,we aim to assess dynamical downscaling simulations by utilizing a novel bias-corrected global climate model(GCM)data to drive a regional climate model(RCM)over the Asia-western North Pacific region.Three simulations were conducted with a 25-km grid spacing for the period 1980–2014.The first simulation(WRF_ERA5)was driven by the European Centre for Medium-Range Weather Forecasts Reanalysis 5(ERA5)dataset and served as the validation dataset.The original GCM dataset(MPI-ESM1-2-HR model)was used to drive the second simulation(WRF_GCM),while the third simulation(WRF_GCMbc)was driven by the bias-corrected GCM dataset.The bias-corrected GCM data has an ERA5-based mean and interannual variance and long-term trends derived from the ensemble mean of 18 CMIP6 models.Results demonstrate that the WRF_GCMbc significantly reduced the root-mean-square errors(RMSEs)of the climatological mean of downscaled variables,including temperature,precipitation,snow,wind,relative humidity,and planetary boundary layer height by 50%–90%compared to the WRF_GCM.Similarly,the RMSEs of interannual-tointerdecadal variances of downscaled variables were reduced by 30%–60%.Furthermore,the WRF_GCMbc better captured the annual cycle of the monsoon circulation and intraseasonal and day-to-day variabilities.The leading empirical orthogonal function(EOF)shows a monopole precipitation mode in the WRF_GCM.In contrast,the WRF_GCMbc successfully reproduced the observed tri-pole mode of summer precipitation over eastern China.This improvement could be attributed to a better-simulated location of the western North Pacific subtropical high in the WRF_GCMbc after GCM bias correction.
文摘Based on detailed geological and geomorphological mapping, sampling and micro-palaeontological determinations, both of the alpine and neogene formations, new data have been derived for Spetses Island (SW Aegean). The applied methodology provided results on the paleogeographic evolution for Spetses Island and the nearby land of Argolida peninsula as well. Based mainly on characteristic nannofossils, a Miocene age of the post-alpine formations is determined. It is the first time that miocene formations have been identified, not only in Spetses Island and Argolida, but in the whole area of Peloponnesus, where only Plio-pleistocene deposits have been described. This work also leads to the conclusion that Spetses Island is attached to the Argolida peninsula, forming an independent paleogeographic unit since Upper Miocene.
文摘The purpose of this paper is to evaluate control of orientation of foliations and joints on the direction of valley axes in the Stribrne Hory area in the Bohemian-Moravian Highlands in central part of the Czech Republic. This area is predominantly built by metamorphic rocks. It is situated near the Pribyslav deep-seated fault. The data concerning of foliations, joints and valley axes were statistically analyzed and then visually compared according to their distribution using direction roses. Directions of valley axes have generally orientation of NNE-SSW, SE, E-W, NW and WNW and coincide with the system of foliations and ordinarily steep joints.
文摘The world is at a critical state of limited resources,growing population,and increasing hazard potential.In the near future,geoscientists will be sought to solve these worldwide woes or face the consequences of a demanding public.Cheap,innovative technology and collaboration among several disciplines are needed to proceed forward and solve the difficult questions that humanity as a whole faces.Years of advances and dilemmas in earthquake prediction highlight a theme that stretches through all of geoscience and society:the need for quick solutions to pressing global concerns.
文摘The Wadi Natash volcanic field(WNVF)in the south of the Eastern Desert of Egypt is a typical example of well-preserved intraplate alkaline magmatism during the Late Cretaceous,i.e.,prior to the Oligo-Miocene Red Sea rift.We compiled stratigraphic sections at two sectors;namely East Gabal Nuqra and West Khashm Natash(WKN)where the volcanic flows are intercalated with the Turonian Abu Agag sandstone with occasional paleosols when volcanic activity is intermittent.Peridotite mantle xenoliths are encountered in the first sector whereas flows in the second sector are interrupted by trachyte plugs and ring dykes.On a geochemical basis,the maifc melt originating from the lithospheric mantle beneath the WNVF practiced~5%partial melting of phlogopite-bearing garnet peridotite.Basalts dominate in the two sectors and highly evolved(silicic)rocks are confined to the WKN sector.Rejuvenation of ancient Precambrian fractures following the NW-SE and ENE-WSW trends facilitated the ascend of Late Cretaceous mantle-derived alkaline magma.Structurally,the WNVF developed at the eastern shoulder of the so-called"Kom Ombo-Nuqra-Kharit rift system"that represents a well-defined NW-trending intracontinental rift basin in the southern Eastern Desert.In such a structural setup,the Natash volcanic are confined to half-grabens at the East Gabal Nuqra sector whereas the West Khashm Natash sector is subjected to extensional stresses that propagated eastwards.The WNVF is a typical example of fluvial clastics(Turonian)intercalation with rift-related alkaline volcanic rocks in northeast Africa.
文摘Neoproterozoic island arc assemblage of the Arabian–Nubian Shield(ANS)in the Eastern Desert(ED)of Egypt comprises juvenile suites of metavolcanics(MV),large amounts of meta-sedimentary rocks(MS),and voluminous metagabbros-diorites(MGD)and syn-tectonic intrusions of older granitoids(OG).We report here the updates of these four rock units in terms of classification,distribution,chemical characteristics,geodynamic evolution,metamorphism,and ages.In addition,we discuss these integrated data to elucidate a reasonable and reliable model for crustal evolution in the ANS.The main features of these rock units indicate their relation to each other and the geodynamic environment dominated by early immature oceanic island arcs to primitive continental arcs.Integrated information of the island arc metavolcanic and plutonic rocks(gabbros,diorites,tonalites,and granodiorites)furnish evidence of the genetic relationships.These include proximity and a coeval nature in the field;all protolith magmas are subalkaline in nature following calc-alkaline series with minor tholeiitic affinities;common geochemical signature of the arc rocks and subduction-related magmatism;their similar enrichment in LREEs;and similar major element compositions with mafic melts derived from metasomatized mantle wedge.The volcano-sedimentary and the OG rocks underwent multiphase deformation events whereas the MGD complexes deformed slightly.Based on the magmatic,sedimentological,and metamorphic evolutions constrained by geochronological data as well as the progressive evolutionary trend from extensional to compressional regimes,a possible gradual decrease in the subducted slab dip angle is the most infl uential in any geodynamic model for arc assemblage in the ED of Egypt.
文摘Opencast coal mining produces trash of soil and rock containing various minerals,that are usually dumped nearby the abandoned sites which causes severe environmental concern including the production of acid mine drainage(AMD)through oxidation pyrite minerals.The current study entailed assessing the potential production of AMD from an opencast coal mining region in Northeast part of India.In order to have a comprehensive overview of the AMD problem in Makum coalfield,the physico-chemical,geochemical,and petrological characteristics of the coal and overburden(OB)samples collected from the Makum coalfield(Northeast India)were thoroughly investigated.The maceral compositions reveal that coal features all three groups of macerals(liptinite,vitrinite,and inertinite),with a high concentration of liptinite indicating the coal of perhydrous,thereby rendering it more reactive.Pyrite(FeS_(2))oxidation kinetics were studied by conducting the aqueous leaching experiments of coal and(OB)samples to interpret the chemical weathering under controlled laboratory conditions of various temperature and time periods,and to replicate the actual mine site leaching.Inductively coupled plasma-optical emission spectroscopy(ICP-OES)was operated to detect the disposal of some precarious elements from coal and OB samples to the leachates during our controlled leaching experiment.The Rare earth element(REE)enrichment in the samples shows the anthropogenic incorporation of the REE in the coal and OB.These experiments reveal the change in conductivity,acid producing tendency,total dissolved solid(TDS),total Iron(Fe)and dissolved Sulfate(SO_(4)^(2−))ions on progress of the leaching experiments.Moreover,the discharge of FeS_(2) via atmospheric oxidation in laboratory condition undergoes a significant growth with the rise of temperature of the reaction systems in the environment and follows pseudo first order kinetics.A bio-remediative strategies is also reported in this paper to mitigate AMD water by employing size-segregated powdered limestone and water hyacinth plant in an indigenously developed site-specific prototype station.Apart from neutralisation of AMD water,this eco-friendly AMD remediation strategy demonstrates a reduction in PHEs concentrations in the treated AMD water.
基金supported by the Basic Research Project(21-3411)of the Korea Institute of Geoscience and Mineral Resourcesthe National Research Foundation of Korea(NRF)under the Ministry of Science and ICT(No.RS-2023-00210810).
文摘The volatility of water resources is increasing owing to climate change,and various developments are being undertaken for a stable supply of water resources.Among the many available water resources,groundwater is attracting attention as one of the country’s most important resources in Korea.This study developed a groundwater potential map(GPM)for the exploration of groundwater in the Geumgang River basin,one of the four major river basins in Korea.This consisted of ten thematic layers(hydrogeology,fractured zone,depth to groundwater level,distance to surface water,lineament density,slope,stream drainage density,soil drainage,land cover,and annual rainfall)of remotely sensed data and satellite images to explore a wide range of areas.Each thematic layer was weighted through Analytical Hierarchal Process and Technique for Order Preference by Similarity to Ideal Solution,and the groundwater potential was determined.The final GPM are classified into five categories:very high,high,moderate,low,and very low.To verify the GPM,specific capacity data from a total of 2,671 wells was used.The GPM in this study make groundwater to be considered as promising and feasible alternative resource to surface water in case of future climate crisis such as heavy drought.
基金funded by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant from the Ministry of Trade,Industry and Energy(MOTIE)(No.20198210100030,20208310100020)the Nuclear Safety Research Program through the Korea Foundation of Nuclear Safety(KoFONS)grant from the Nuclear Safety and Security Commission(NSSC)(No.071610)of the Republic of Korea.
文摘Five sequences of deep fluid injections at the Pohang Enhanced Geothermal System(EGS)triggered an ML 5.4 earthquake on November 15,2017.The foreshock-mainshock-aftershock sequence was monitored using dense seismic networks.Between November 14,2017,and May 31,2023,this study detected 5,169 earthquakes and determined the relative locations of 4,902 earthquakes,including seven foreshocks.A heterogeneous subsurface fault model is proposed,in which the fault is reactivated by induced and triggered earthquakes.The earthquake frequency decreased after the mainshock,with a temporary increase after the ML 4.6 event on February 10,2018.The magnitude-frequency b-values are significantly lower than those for the background seismicity in the Korean Peninsula and those for the 2016 Gyeongju earthquake sequence.The aftershock decay rate p-values are within the range of typical values,regardless of decreasing over time.The earthquake focal mechanisms exhibit a predominance of strike-slip components,whereas the slip tendency indicates a higher value in reverse faulting geometry,implying stress redistribution after the mainshock.The seismic landscape with ongoing aftershock activity after the 2017 Pohang earthquake underscores the importance of sustained,long-term seismic monitoring to comprehensively grasp the implications of the new seismic environment for seismic hazards in the area.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(NRF-2018R1A5A7025409,NP2018-026)the Energy&Mineral Resources Development Association of Korea(EMRD)grant funded by the Korea government(MOTIE)(2021060001).
文摘For the Anthropocene to get recognized as a real geological era,first and foremost its strata must be identified.Several geological formations such as bogs,lakebeds,reefs,ice sheets,speleothems,river estuary deposits,and sea floors have been considered as potential candidates for the Anthropocene strata.This consideration arises from the emergence of novel materials associated with the Anthropocene,including radioactive isotopes,plastics,and aluminum,started to be discovered in their sediments and dramatically increased since the mid-20th century.Yet,these deposits are no longer considered‘natural’because human activities are largely controlling the transport and depositional processes from source to sink.The Municipal Solid Waste(MSW)in landfills has been also‘unnaturally’transported and deposited(landfilled)by humans.Since the 1950s,the controlled landfills have been made worldwide,and thus the opening time of the landfills is clear.The MSW layers of landfills,which appeared globally,contemporaneously,and with distinct characteristics,are indeed the‘artificial(anthropogenic)’strata showing a new and clear aspect of human influence,unprecedented in geological time.The MSW layers can be considered valuable indicators of the Anthropocene era because they not only preserve the history of human life but also sensitively demonstrate the scale of human activities like mass production,consumption,and disposal.The MSW layers can be expected to serve as a unique window into the Anthropocene.
文摘The Anthropocene as a prospective new,ongoing series/epoch must be defensible against all relevant concerns.We address the seven,still-relevant challenges posed to the Anthropocene Working Group by the Chair,International Commission on Stratigraphy(ICS),in 2014.(1)Concept or reality?The Anthropocene possesses a substantial,sharply distinctive stratigraphic record recognisable through many proxy signals from the mid-20th century onwards;(2)GSSP or GSSA?The Anthropocene can be defined by a GSSP and correlated globally;(3)Past or future?The Anthropocene unquestionably represents geological time,its transformations having already moved the Earth System beyond Holocene norms towards an irreversible future trajectory;(4)Utility?The Anthropocene’s distinctive material content allows useful delineation on geological sections/maps;(5)Indelibility?Many of the Anthropocene’s transformative effects cannot be subsequently effaced or overprinted;(6)Fit within the Geological Time Scale(GTS)?The Anthropocene represents a unique,youngest,interval in Earth history and strata of profound significance;(7)What is its value?The chronostratigraphic Anthropocene has conceptual usefulness even informally,but would then lack the clarity,stability and recognition that formalization provides.Without its formalization,the GTS would no longer accurately reflect Earth history,diminishing the relevance of geological science for analysis of ongoing planetary change.
