Diamonds were formed in the mantle lithosphere,mostly at depths of 150~200km in the centres of Precambrian cratons,the buoyant ancient cores of continents.From there they were normally transported into the upper crust...Diamonds were formed in the mantle lithosphere,mostly at depths of 150~200km in the centres of Precambrian cratons,the buoyant ancient cores of continents.From there they were normally transported into the upper crust in kimberlite pipes whose diamonds are largely colourless and light yellow related to trace element N(Ia type),although brown,green,and more rarely blue-coloured diamonds are related to lattice defect and trace amounts of H,more rarely B and Ni.Pink diamonds are extremely rare in the approximately 90 diamondiferous pipes mined globally.Although small quantities have been discovered elsewhere,about 90%have been mined from the ca.1.3Ga Argyle diamond pipe in Western Australia,with the Arkhangelskaya diamond pipe in Russia the only other significant source.The pink colour at both Argyle and Arkhangelskaya is unrelated to trace elements and instead results from absorption of light from nanoscale(550nm)defects related to shear stress and plastic deformation.Macroscopically,defects are shown by glide planes,lamellae,and grain lines imposed on the originally colourless diamonds derived from their mantle source.The key question is why these defects were uniquely acquired in diamonds in the Argyle and Arkhangelskaya pipes.Unlike most diamondiferous pipes,Argyle is a rare diamondiferous volatile-rich lamproite pipe that was emplaced into the multiply deformed and rifted NNE-trending Halls Creek Orogen on the margin of the Kimberley Craton.Similarly,Arkhangelskaya in the Devonian Lomonosov kimberlite cluster is a volatile-rich low-Ti type kimberlite,a close relative to lamproite,that was emplaced into the multiply deformed Lapland-Kola Orogen on the rifted margin of the Kola Craton.These craton margins are underlain by subduction-induced volatile-enriched metasomatized mantle lithosphere in contrast to the more primeval mantle under craton centres.It is thus likely that shear stresses were exacerbated at Argyle and Arkangelskaya by rapid vertical emplacement of the anomalous volatile-enriched magmas at supercritical pressures and temperatures,that induced catastrophic phase separation of these volatiles and'mini seismic events'during rapid pressure drops during ascent from 200km depth to the surface.Such a mechanism is consistent with the presence of strongly resorbed and plastically deformed small brown industrial diamonds in the Argyle pipe.From a China perspective,it is potentially important that at 1.3Ga the alkaline Argyle pipe in northern Australia is placed adjacent to the North China Craton(NCC),with numerous world-class mineral deposits including the giant ca.1.4~1.2Ga alkaline Bayan Obo REE system on its margin.However,it is the southeastern margin of the Yangtze Craton and the Jiangnan Orogen with their lamproite pipes derived from metasomatized mantle lithosphere that present the most prospective regions for pink diamond occurrences.展开更多
City,Street and Citizen:The Measure of the Ordinary Author:Suzanne Hall Year:2012Publisher:Routledge ISBN:978-0-415-68865-9(176 pages,in English)1.City streets from a marginal perspective Streets are the most common s...City,Street and Citizen:The Measure of the Ordinary Author:Suzanne Hall Year:2012Publisher:Routledge ISBN:978-0-415-68865-9(176 pages,in English)1.City streets from a marginal perspective Streets are the most common space in a city.However,it is these countless streets that constitute the spatial stage for the social life of the general public in a city.Meanwhile,socially speaking,streets also act as an essential part that builds the public sphere of a city.展开更多
The formation of Caosiyao giant porphyry Mo deposit is related to three granitic porphyries:coarse-grained granite porphyry(CG),fine-grained granite porphyry(FG),and giant plagioclase phenocryst bearing granite porphy...The formation of Caosiyao giant porphyry Mo deposit is related to three granitic porphyries:coarse-grained granite porphyry(CG),fine-grained granite porphyry(FG),and giant plagioclase phenocryst bearing granite porphyry(PG).To investigate the mineralization significance of three porphyries,Microthermometry,Laser micro-Raman Spectra,and H-O-He-Ar isotope analyses of fluid inclusions were conducted.Intermediate density with high temperatures(>550℃)and moderate-low salinities(~10 wt.%)characterizes CG-related initial exsolved fluids.Vapor-rich and brine phases separated from the initial fluid following a continuous decrease in pressure and temperature,inducing molybdenite precipitation.FG-related initial fluids are characterized by high temperatures(>550℃)and salinities(>65 wt.%).The mixing of low-salinity fluids led to a rapid decrease in the salinity of FG-related fluid,promoting the deposit of the Mo element.The lead-zinc mineralization is closely related to the FG-related fluid,and the addition of meteoric fluid induced the formation of galena and sphalerite.The ore-forming fluid related to the PG is CO_(2)-rich and accompanied by the addition of mantle-derived He-Ar.The presence of CO_(2) did not contribute to the solubility of Mo,resulting in the absence of a considerable amount of molybdenite.展开更多
Earthquakes are critical triggers for slope instability.While extensive research has been conducted on slope failure modes under seismic loading,the identification of sliding surface propagation and coalescence remain...Earthquakes are critical triggers for slope instability.While extensive research has been conducted on slope failure modes under seismic loading,the identification of sliding surface propagation and coalescence remains insufficiently explored.This study investigates the dynamic response of a deposit slope containing a weak interlayer through large-scale shaking table tests.The propagation process of the sliding surface was identified using the Hilbert-Huang transform and marginal spectrum analysis.Under seismic excitation,sliding occurs along the interface between the overburden and the weak interlayer,leading to sudden landslide events.Differential vibrations at the overburden-weak interlayer-bedrock interfaces are identified as a primary mechanism driving landslide initiation.As input acceleration increases,these interfacial vibration contrasts intensify,and the acceleration amplification effect within the overburden becomes markedly pronounced.Following landslide occurrence,the vibration differences across interfaces decrease sharply.In the time-frequency domain,seismic waves transmitted through the weak interlayer exhibit amplified low-frequency components.Marginal spectrum analysis of seismic energy evolution within the slope reveals that energy attenuation in the 19-22 Hz frequency band correlates with landslide occurrence,while attenuation in the 9-11 Hz band serves as an indicator for sliding surface propagation and coalescence.For seismic design of deposit slopes with weak interlayers,particular attention should be given to the increased seismic inertial forces in the overburden layer and the detrimental effects of low-frequency wave components on sliding surface development.展开更多
Predicting Antarctic sea ice is of substantial academic and practical significance.However,current prediction models,including deep learning(DL)-based models,show notable bias in the marginal ice zone.In this study,we...Predicting Antarctic sea ice is of substantial academic and practical significance.However,current prediction models,including deep learning(DL)-based models,show notable bias in the marginal ice zone.In this study,we developed a pure data-driven DL model for predicting the Antarctic austral summer monthly-to-seasonal sea ice concentration(SIC)by incorporating a novel hybrid sea ice edge constraint loss function(HybridLoss).The model is referred to as ASICNet.Independent testing based on the last five years(2019–23)demonstrates that ASICNet with HybridLoss achieves significantly higher skill metrics than without,with a reduced mean absolute error of 0.021 from 0.022,a reduced integrated ice edge error of 1.714×10^(6)from 1.794×10^(6)km^(2),but an increased pattern correlation coefficient of 0.40 from 0.38,although both ASICNet versions outperform dynamical and statistical models.Furthermore,enhanced heat maps were developed to interpret the predictability sources of sea ice within DL-based models,and the results suggest that the predictability of Antarctic sea ice is attributable to factors like the Antarctic Dipole(ADP),Amundsen Sea Low(ASL),and Southern Ocean sea surface temperature(SST),as revealed in previous studies.Thus,ASICNet is an efficient tool for austral summer Antarctic SIC prediction.展开更多
The authors extend the marginal coordinate test for predictor contribution(Cook,2004)to the case with multivariate responses.Instead of explicitly specifying the link functions between the responses and the predictors...The authors extend the marginal coordinate test for predictor contribution(Cook,2004)to the case with multivariate responses.Instead of explicitly specifying the link functions between the responses and the predictors,an asymptotic test is proposed under the normality assumption of the predictors as well as an asymmetry assumption about the unknown regression mean function.When these assumptions are violated,the asymptotic test with elliptical trimming and clustering is still valid with desirable numerical performances.展开更多
Ecosystems along the eastern margin of the Qinghai-Tibet Plateau(EQTP)are highly fragile and extremely sensitive to climate change and human disturbances.To quantitatively assess climate-induced ecosystem responses,th...Ecosystems along the eastern margin of the Qinghai-Tibet Plateau(EQTP)are highly fragile and extremely sensitive to climate change and human disturbances.To quantitatively assess climate-induced ecosystem responses,this study proposes a Climate-Induced Productivity Index(CIPI)based on the Super Slack-Based Measure(Super-SBM)model using remote sensing data from 2001 to 2020.The results reveal persistently low CIPI values(0.47-0.53)across major ecosystem types,indicating widespread vulnerability to climatic variability.Among these ecosystems,forests exhibit the highest CIPI(0.55),followed by shrublands(0.54),croplands(0.53),grasslands(0.51),and barelands(0.43).The Theil index analysis further demonstrates significant intra-group disparities,suggesting that extreme climatic events amplify CIPI heterogeneity.Moreover,the dominant environmental drivers differ among ecosystem types:the Palmer Drought Severity Index(PDSI)primarily constrains grassland productivity,solar radiation(SRAD)strongly influences shrub and cropland systems,whereas subsurface factors exert greater control in forested regions.This study provides a quantitative framework for evaluating climate-ecosystem interactions and offers a scientific basis for long-term ecological monitoring and security planning across the EQTP.展开更多
Based on the plate tectonics theory,the sedimentary environment of paleotectonics along the passive continental margins on both sides of the South Atlantic Ocean was reconstructed using the paleomagnetic,regional geol...Based on the plate tectonics theory,the sedimentary environment of paleotectonics along the passive continental margins on both sides of the South Atlantic Ocean was reconstructed using the paleomagnetic,regional geological,and seismic data,and the intrinsic relationships of hydrocarbon distribution in the passive continental margin basins and the differential hydrocarbon accumulation patterns were analyzed.Results show that basins on both sides of the South Atlantic experienced two major extensional phases—rift and depression—and four evolutionary stages:the Early Cretaceous Berriasian-Barremian intracontinental rift stage,the Early Cretaceous Aptian-Albian intercontinental rift to initial drift transition stage,the Late Cretaceous-Paleogene drift-related marine transgressive depression stage,and the Neogene-Quaternary drift-related marine regressive depression stage.According to basin architecture and superposition style,the passive-margin basins are classified into two principal types:rift-continental marginal depression composite and continental marginal depression-dominated.The basins in the study area were further divided into six types based on the development degree of salt tectonics and the type of dominant sand bodies,i.e.salt-free rift-continental marginal gravity-flow composite type,salt-free rift-continental marginal delta composite type,salt-bearing rift-continental marginal gravity flow composite type,delta-dominated salt-bearing rift-continental marginal delta composite type,gravity-flow-dominated continental marginal depression type,and delta-dominated continental marginal depression type.The salt-free rift-continental marginal gravity flow and delta composite basins are mainly distributed in the southern segment.The salt-bearing rift-continental marginal gravity flow and delta composite basins are mainly distributed in the central segment.The gravity-flow-dominated continental marginal depression basins are mainy distributed in the northern segment.The delta-dominated passive-margin depression basins are distributed in three segments from north to south.In different types of basins,distinctive depositional systems and source-reservoir-caprock assemblages were formed in each upper/lower structure layer.The superimposition and evolution of multi-phase prototype basins result in the orderly hydrocarbon accumulation vertically and laterally,which are“segmented along-strike,zoned across-strike,and layered vertically”.展开更多
Vaccination is the preferred strategy for preventing infections such as influenza in elderly individuals;however,its efficacy is often suboptimal due in part to age-related declines in immune function.In this study,we...Vaccination is the preferred strategy for preventing infections such as influenza in elderly individuals;however,its efficacy is often suboptimal due in part to age-related declines in immune function.In this study,we discovered that the infusion of mesenchymal stromal cells(MSCs)restored defects in the splenic stromal cell network and lymphocyte architecture in aged mice while also increasing specific antibody levels following vaccine immunization.This significantly protected aging mice from influenza infection.Mechanistically,the delivered MSCs localized in the splenic marginal zones,where they positioned themselves near marginal reticular cells(MRCs)and stimulated MRC proliferation,partially through the action of vascular endothelial growth factor A(VEGFA).This MSC‒MRC interaction orchestrated the reconstruction of the stromal network,thereby restoring lymphocyte homeostasis and germinal center reactions.Importantly,the MSC-mediated enhancement of the vaccine response was further validated in aged cynomolgus monkeys.Collectively,our findings provide new insights into the application of MSCs in addressing age-related immune decline and highlight splenic MRCs as critical therapeutic targets.展开更多
This paper studies the context of the central area contiguous with the iron bed of medium-sized cities of the northwest region of São Paulo,in Brazil,namely:Presidente Prudente,Araçatuba,Birigüi,Sã...This paper studies the context of the central area contiguous with the iron bed of medium-sized cities of the northwest region of São Paulo,in Brazil,namely:Presidente Prudente,Araçatuba,Birigüi,São Josédo Rio Preto and Marilia.Not surprisingly,the ancient boundaries of railway lines crossing the countryside regions.These urban centers were developed by the expansion of the railway,but with the deactivation of the rail transport,its core areas went into obsolescence and deterioration process and,more recently,are suffering processes of modernization and productive restructuring.At the same time,amid the industrial landscapes and decaying railroad heritage,there are situations and dweller types able to reveal some imaginary,capable of triggering:surprises,dilemmas and entanglements in the analysis of urban composition,the modernization process and its consequent deterioration.Therefore,from the marginal uses present in each city of the northwestern country towns of São Paulo,we try explain a poltical and critical point of view of these urban areas.Thus,the marginal architecture is not only the expression of subaltern subjectivities,reflecting the complexities present in emblematic areas of public importance,affected by degradation processes,but also,the attempt to define a concept strategy:a destabilizing way of reading places filled with meaning,in the counterculture of the hegemonic space to make experimental projects.展开更多
The Litang fault zone is an important seismogenic structure along the southeastern margin of the Tibetan Plateau.It caused the M71/4 earthquake in Litang in 1948 AD.The fault zone intersects the Sichuan-Xizang transpo...The Litang fault zone is an important seismogenic structure along the southeastern margin of the Tibetan Plateau.It caused the M71/4 earthquake in Litang in 1948 AD.The fault zone intersects the Sichuan-Xizang transportation corridor and poses a serious risk to its safe operation.This study,utilizing high-resolution remote sensing interpretation,field geological verification,UAV photogrammetry,UAV LiDAR,paleoearthquake trench excavation,and AMS^(14)C and OSL dating methods,reveals the geometric structure,slip rates,paleoearthquake sequence,and earthquake rupture segmentation of the Litang fault zone;analyzes the rupture distribution range of the 1729 AD Litang earthquake and estimates its magnitude.The study indicates that the Litang fault zone is a relatively immature strike-slip fault,which has developed as a new active fault zone within the Northwestern Sichuan sub-block during the southeastward material migration of the southeastern margin of the Tibetan Plateau.This reflects a transformation in the deformation model of the Northwestern Sichuan sub-block crust from the‘Rigid Block’model to the‘Continuous Deformation’model.展开更多
The presence of a positive deep surgical margin in tongue squamous cell carcinoma(TSCC)significantly elevates the risk of local recurrence.Therefore,a prompt and precise intraoperative assessment of margin status is i...The presence of a positive deep surgical margin in tongue squamous cell carcinoma(TSCC)significantly elevates the risk of local recurrence.Therefore,a prompt and precise intraoperative assessment of margin status is imperative to ensure thorough tumor resection.In this study,we integrate Raman imaging technology with an artificial intelligence(AI)generative model,proposing an innovative approach for intraoperative margin status diagnosis.This method utilizes Raman imaging to swiftly and non-invasively capture tissue Raman images,which are then transformed into hematoxylin-eosin(H&E)-stained histopathological images using an AI generative model for histopathological diagnosis.The generated H&E-stained images clearly illustrate the tissue’s pathological conditions.Independently reviewed by three pathologists,the overall diagnostic accuracy for distinguishing between tumor tissue and normal muscle tissue reaches 86.7%.Notably,it outperforms current clinical practices,especially in TSCC with positive lymph node metastasis or moderately differentiated grades.This advancement highlights the potential of AI-enhanced Raman imaging to significantly improve intraoperative assessments and surgical margin evaluations,promising a versatile diagnostic tool beyond TSCC.展开更多
Climate change has significantly increased the frequency and severity of droughts and risk of tree death worldwide.Differences in leaf habit,plant size,and species diversity are associated with differences in the risk...Climate change has significantly increased the frequency and severity of droughts and risk of tree death worldwide.Differences in leaf habit,plant size,and species diversity are associated with differences in the risk of drought-induced mortality,but the relative contributions of these factors to the risk of mortality are unclear.In a study of the mortality of tree and shrub species during the extreme drought of 2019 in a savanna ecosystem in Southwest China,we assessed the relative contributions of evergreen and deciduous leaf habit,plant size,and species richness and diversity to the mortality of shrubs and trees after the 2019 extreme drought.The deciduous species had significantly lower hydraulic safety margins than the coexisting evergreen species,resulting in a higher mortality risk.Additionally,species and individuals with taller canopies tended to have deeper root systems,an advantage during extreme drought that reduced mortality risk.Notably,mortality risk was largely independent of stand species richness and diversity.Overall,leaf habit and plant height were better predictors of mortality risk than species richness and diversity.These novel insights provide a better understanding of the mechanisms driving drought-induced mortality in the ecosystems with a low canopy and weak interspecific and intraspecific competition for shared resources.Leaf habit and tree size should be incorporated into hypotheses on the mechanisms underlying drought-induced tree mortality.展开更多
Based on the comprehensive analysis of data from petrology and mineralogy,well logging,seismic surveys,paleontology,and geochemistry,a detailed research was conducted on paleoenvironmental and paleoclimatic conditions...Based on the comprehensive analysis of data from petrology and mineralogy,well logging,seismic surveys,paleontology,and geochemistry,a detailed research was conducted on paleoenvironmental and paleoclimatic conditions,and modeling of the source rocks in the second member of the Eocene Wenchang Formation(Wen 2 Member)in the Northern Shunde Subsag at the southwestern margin of the Pearl River Mouth Basin.The Wen 2 Member hosts excellent,thick lacustrine source rocks with strong longitudinal heterogeneity and an average total organic carbon(TOC)content of over 4.9%.The Wen 2 Member can be divided into three units(I,II,III)from bottom to top.Unit I features excellent source rocks with Type I organic matters(average TOC of 5.9%)primarily sourced from lake organisms;Unit II hosts source rocks dominated by Type II2 organic matters(average TOC of 2.2%),which are originated from mixed sources dominated by terrestrial input.Unit III contains good to excellent source rocks dominated by Type II1 organic matters(average TOC of 4.9%),which are mainly contributed by lake organisms and partially by terrestrial input.Under the background of rapid subsidence and limited source supply during intense rifting period in the Eocene,excellent source rocks were developed in Wen 2 Member in the Northern Shunde Subsag under the coordinated control of warm and humid climate,volcanic activity,and deep-water reducing conditions.During the deposition of Unit I,the warm and humid climate and volcanic activity promoted the proliferation of lake algaes,primarily Granodiscus,resulting in high initial productivity,and deep-water reducing conditions enabled satisfactory preservation of organic matters.These factors jointly controlled the development and occurrence of excellent source rocks.During the deposition of Unit II,a transition from warm to cool and semi-arid paleoclimatic conditions led to a decrease in lake algaes and initial productivity.Additionally,enhanced terrestrial input and shallow-water,weakly oxidizing water conditions caused a significant dilution and decomposition of organic matters,degrading the quality of source rocks.During the deposition of Unit III,when the paleoclimatic conditions are cool and humid,Pediastrum and Botryococcus began to thrive,leading to an increase in productivity.Meanwhile,the reducing environment of semi-deep water facilitated the preservation of excellent source rocks,albeit slightly inferior to those in Unit I.The study results clarify the differential origins and development models of various source rocks in the Shunde Sag,offering valuable guidance for evaluating source rocks and selecting petroleum exploration targets in similar marginal sags.展开更多
Based on a set of high-resolution 3D seismic data from the northern continental margin of the South China Sea,the lithospheric structure,thinning mechanisms and related syn-rift tectonic deformation response processes...Based on a set of high-resolution 3D seismic data from the northern continental margin of the South China Sea,the lithospheric structure,thinning mechanisms and related syn-rift tectonic deformation response processes in the crustal necking zone in the deepwater area of the Pearl River Mouth Basin were systematically analyzed,and the petroleum geological significance was discussed.The necking zone investigated in the study is located in the Baiyun Sag and Kaiping Sag in the deepwater area of the Pearl River Mouth Basin.These areas show extreme crustal thinned geometries of central thinning and flank thickening,characterized by multi-level and multi-dipping detachment fault systems.The necking zone exhibits pronounced lateral heterogeneity in structural architectures,which can be classified into four types of thinned crustal architectures,i.e.the wedge-shaped extremely thinned crustal architecture in the Baiyun Main Sub-sag,dumbbell-shaped moderately thinned crustal architecture in the Baiyun West Sub-sag,box-shaped weakly thinned crustal architecture in eastern Baiyun Sag,and metamorphic core complex weakly thinned crustal architecture in the Kaiping Sag.This shows great variations in the degree and style of crustal thinning,types of detachment faults,distribution of syn-rift sedimentary sequences,and intensity of magmatism.The thinning of the necking zone is controlled by the heterogeneous rheological stratification of lithosphere,intensity of mantle-derived magmatism,and deformation modes of detachment faults.The syn-rift tectonic deformation of the necking zone evolved through three phases,i.e.uniform stretching during the early Wenchang Formation deposition period,necking during the late Wenchang Formation deposition period,and hyperextension during the Enping Formation deposition period.The crustal thinning extent and architectural differentiation in these phases were primarily controlled by three distinct mechanisms,i.e.the pure shear deformation activation of pre-existing thrust faults,the simple shear deformation of crust-mantle and inter-crust detachment faults,and differential coupling of lower crustal flow and ductile domes with main detachment faults.The hydrocarbon accumulation and enrichment in the necking zone exhibit marked spatial heterogeneity.Four distinct crustal thinned architecture-hydrocarbon accumulation models were identified in this study.The hydrocarbon accumulations in the shallow part exhibit significant correlations with their deep crustal thinned architectures.The unique lithospheric structure and deformation process predominantly control the favorable hydrocarbon accumulation zones with excellent source-fault-ridge-sand configurations,which is critical to reservoir-forming.The most promising exploration targets are mainly identified on the uplift zones and their seaward-dipping flanks associated with the middle and lower crustal domes.This research provides additional insights into lithospheric thinning-breakup process at intermediate continental margins of marine sedimentary basins,being significant for guiding the deepwater petroleum exploration in the Pearl River Mouth Basin.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
BACKGROUND Postpancreatectomy hemorrhage is one of the most severe and life-threatening complications after pancreaticoduodenectomy.We present four cases of gastrointestinal bleeding patients to clarify its appropriat...BACKGROUND Postpancreatectomy hemorrhage is one of the most severe and life-threatening complications after pancreaticoduodenectomy.We present four cases of gastrointestinal bleeding patients to clarify its appropriate treatment and prevention.CASE SUMMARY The main symptoms included black stool,hematochezia,haematemesis,blood in the nasogastric tube,and hemorrhagic shock.The mean age was 66.25 years old and the median onset time was 340 d after the surgery.The bleeding location comprised gastrointestinal anastomosis,bile duct-jejunum anastomosis,and extraluminal bleeding.The possible causes included marginal ulcer,jejunal varix,and abdominal infection.Endoscopic hemostatic clips,as well as a covered stent using angiography,were utilized to stop the bleeding and three patients survived.Only one patient died of gastrointestinal bleeding,abdominal bleeding,abdominal infection,hypovolemic shock,and disseminated intravascular coagulation.CONCLUSION Early and effective endoscopic intervention is the key to successful hemostasis in patients with gastrointestinal bleeding after pancreatoduodenectomy.展开更多
The Cambrian platform margin in the Tarim Basin boasts favorable source-reservoir-cap assemblages,making it a significant target for hydrocarbon exploration in ultra-to extra-deep facies-controlled for-mations.Of the ...The Cambrian platform margin in the Tarim Basin boasts favorable source-reservoir-cap assemblages,making it a significant target for hydrocarbon exploration in ultra-to extra-deep facies-controlled for-mations.Of the three major basins in western China,Tarim is the only basin with large-scale platform margin where no exploration breakthrough has been achieved yet.This study determines the vertical and lateral differential evolution of the platform margin(in the Manxi area hereafter referred to as the Cambrian Manxi platform margin)through fine-scale sequence stratigraphic division and a segmented analysis.The platform margin can be divided into the Yuqi,Tahe,Shunbei,and Gucheng segments,from north to south,based on the development of different ancient landforms and the evolutionary process of the platform.The Yuqi and Shunbei segments exhibit relatively low-elevation ancient landforms.Both segments were in a submarine buildup stage during the Early Cambrian,resulting in overall limited scales of their reservoirs.The Gucheng segment features the highest-elevation ancient landforms and accordingly limited accommodation spaces.As a result,the rapid lateral migration of high-energy facies zones leads to the development of large-scale reservoirs with only limited thicknesses.In contrast,the Tahe segment,exhibiting comparatively high-elevation ancient landforms,is identified as the most favorable segment for the formation of large-scale reservoirs.The cap rocks of the platform margin are dominated by back-reef dolomitic flats and tight carbonate rocks formed in transgressive periods.A comprehensive evaluation of source rocks,reservoirs,and cap rocks indicates that the Tahe segment boasts the optimal hydrocarbon accumulation conditions along the platform margin.In this segment,the Shayilike Formation transgressive deposits and the high-energy mound-shoal complexes along the platform margin of the Wusonggeer Formation constitute the optimal reservoir-cap rock assemblage,establishing this segment as the most promising target for hydrocarbon exploration in the platform margin.展开更多
文摘Diamonds were formed in the mantle lithosphere,mostly at depths of 150~200km in the centres of Precambrian cratons,the buoyant ancient cores of continents.From there they were normally transported into the upper crust in kimberlite pipes whose diamonds are largely colourless and light yellow related to trace element N(Ia type),although brown,green,and more rarely blue-coloured diamonds are related to lattice defect and trace amounts of H,more rarely B and Ni.Pink diamonds are extremely rare in the approximately 90 diamondiferous pipes mined globally.Although small quantities have been discovered elsewhere,about 90%have been mined from the ca.1.3Ga Argyle diamond pipe in Western Australia,with the Arkhangelskaya diamond pipe in Russia the only other significant source.The pink colour at both Argyle and Arkhangelskaya is unrelated to trace elements and instead results from absorption of light from nanoscale(550nm)defects related to shear stress and plastic deformation.Macroscopically,defects are shown by glide planes,lamellae,and grain lines imposed on the originally colourless diamonds derived from their mantle source.The key question is why these defects were uniquely acquired in diamonds in the Argyle and Arkhangelskaya pipes.Unlike most diamondiferous pipes,Argyle is a rare diamondiferous volatile-rich lamproite pipe that was emplaced into the multiply deformed and rifted NNE-trending Halls Creek Orogen on the margin of the Kimberley Craton.Similarly,Arkhangelskaya in the Devonian Lomonosov kimberlite cluster is a volatile-rich low-Ti type kimberlite,a close relative to lamproite,that was emplaced into the multiply deformed Lapland-Kola Orogen on the rifted margin of the Kola Craton.These craton margins are underlain by subduction-induced volatile-enriched metasomatized mantle lithosphere in contrast to the more primeval mantle under craton centres.It is thus likely that shear stresses were exacerbated at Argyle and Arkangelskaya by rapid vertical emplacement of the anomalous volatile-enriched magmas at supercritical pressures and temperatures,that induced catastrophic phase separation of these volatiles and'mini seismic events'during rapid pressure drops during ascent from 200km depth to the surface.Such a mechanism is consistent with the presence of strongly resorbed and plastically deformed small brown industrial diamonds in the Argyle pipe.From a China perspective,it is potentially important that at 1.3Ga the alkaline Argyle pipe in northern Australia is placed adjacent to the North China Craton(NCC),with numerous world-class mineral deposits including the giant ca.1.4~1.2Ga alkaline Bayan Obo REE system on its margin.However,it is the southeastern margin of the Yangtze Craton and the Jiangnan Orogen with their lamproite pipes derived from metasomatized mantle lithosphere that present the most prospective regions for pink diamond occurrences.
文摘City,Street and Citizen:The Measure of the Ordinary Author:Suzanne Hall Year:2012Publisher:Routledge ISBN:978-0-415-68865-9(176 pages,in English)1.City streets from a marginal perspective Streets are the most common space in a city.However,it is these countless streets that constitute the spatial stage for the social life of the general public in a city.Meanwhile,socially speaking,streets also act as an essential part that builds the public sphere of a city.
基金financially supported by the National Natural Science Foundation of China(No.42102084)the Special Research Fund of Natural Science(Special Post)of Guizhou University(No.2020[27])Guizhou Provincial Science and Technology Projects(No.ZK[2022]041)。
文摘The formation of Caosiyao giant porphyry Mo deposit is related to three granitic porphyries:coarse-grained granite porphyry(CG),fine-grained granite porphyry(FG),and giant plagioclase phenocryst bearing granite porphyry(PG).To investigate the mineralization significance of three porphyries,Microthermometry,Laser micro-Raman Spectra,and H-O-He-Ar isotope analyses of fluid inclusions were conducted.Intermediate density with high temperatures(>550℃)and moderate-low salinities(~10 wt.%)characterizes CG-related initial exsolved fluids.Vapor-rich and brine phases separated from the initial fluid following a continuous decrease in pressure and temperature,inducing molybdenite precipitation.FG-related initial fluids are characterized by high temperatures(>550℃)and salinities(>65 wt.%).The mixing of low-salinity fluids led to a rapid decrease in the salinity of FG-related fluid,promoting the deposit of the Mo element.The lead-zinc mineralization is closely related to the FG-related fluid,and the addition of meteoric fluid induced the formation of galena and sphalerite.The ore-forming fluid related to the PG is CO_(2)-rich and accompanied by the addition of mantle-derived He-Ar.The presence of CO_(2) did not contribute to the solubility of Mo,resulting in the absence of a considerable amount of molybdenite.
基金financially supported by the National Key Research&Development Program of China(2025YFE0123800)National Natural Science Foundation of China(No.52372343)+4 种基金Sichuan Transportation Science and Technology Project(2023-A-03)Applied Basic Research Programs of Science and Technology Department in Sichuan Province,China(2022NSFSC1086)Sichuan Science and Technology Program(2024YFHZ0121)the R&D Fund Project of China Academy of Railway Science Corporation Limited(K2024G008)National Natural Science Foundation of China(No.52502430).
文摘Earthquakes are critical triggers for slope instability.While extensive research has been conducted on slope failure modes under seismic loading,the identification of sliding surface propagation and coalescence remains insufficiently explored.This study investigates the dynamic response of a deposit slope containing a weak interlayer through large-scale shaking table tests.The propagation process of the sliding surface was identified using the Hilbert-Huang transform and marginal spectrum analysis.Under seismic excitation,sliding occurs along the interface between the overburden and the weak interlayer,leading to sudden landslide events.Differential vibrations at the overburden-weak interlayer-bedrock interfaces are identified as a primary mechanism driving landslide initiation.As input acceleration increases,these interfacial vibration contrasts intensify,and the acceleration amplification effect within the overburden becomes markedly pronounced.Following landslide occurrence,the vibration differences across interfaces decrease sharply.In the time-frequency domain,seismic waves transmitted through the weak interlayer exhibit amplified low-frequency components.Marginal spectrum analysis of seismic energy evolution within the slope reveals that energy attenuation in the 19-22 Hz frequency band correlates with landslide occurrence,while attenuation in the 9-11 Hz band serves as an indicator for sliding surface propagation and coalescence.For seismic design of deposit slopes with weak interlayers,particular attention should be given to the increased seismic inertial forces in the overburden layer and the detrimental effects of low-frequency wave components on sliding surface development.
基金jointly supported by the National Natural Science Foundation of China(Grant No.42376250)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA19070402).
文摘Predicting Antarctic sea ice is of substantial academic and practical significance.However,current prediction models,including deep learning(DL)-based models,show notable bias in the marginal ice zone.In this study,we developed a pure data-driven DL model for predicting the Antarctic austral summer monthly-to-seasonal sea ice concentration(SIC)by incorporating a novel hybrid sea ice edge constraint loss function(HybridLoss).The model is referred to as ASICNet.Independent testing based on the last five years(2019–23)demonstrates that ASICNet with HybridLoss achieves significantly higher skill metrics than without,with a reduced mean absolute error of 0.021 from 0.022,a reduced integrated ice edge error of 1.714×10^(6)from 1.794×10^(6)km^(2),but an increased pattern correlation coefficient of 0.40 from 0.38,although both ASICNet versions outperform dynamical and statistical models.Furthermore,enhanced heat maps were developed to interpret the predictability sources of sea ice within DL-based models,and the results suggest that the predictability of Antarctic sea ice is attributable to factors like the Antarctic Dipole(ADP),Amundsen Sea Low(ASL),and Southern Ocean sea surface temperature(SST),as revealed in previous studies.Thus,ASICNet is an efficient tool for austral summer Antarctic SIC prediction.
文摘The authors extend the marginal coordinate test for predictor contribution(Cook,2004)to the case with multivariate responses.Instead of explicitly specifying the link functions between the responses and the predictors,an asymptotic test is proposed under the normality assumption of the predictors as well as an asymmetry assumption about the unknown regression mean function.When these assumptions are violated,the asymptotic test with elliptical trimming and clustering is still valid with desirable numerical performances.
基金National Key R&D Program of China,No.2022YFF1302401National Natural Science Foundation of China,No.42271007。
文摘Ecosystems along the eastern margin of the Qinghai-Tibet Plateau(EQTP)are highly fragile and extremely sensitive to climate change and human disturbances.To quantitatively assess climate-induced ecosystem responses,this study proposes a Climate-Induced Productivity Index(CIPI)based on the Super Slack-Based Measure(Super-SBM)model using remote sensing data from 2001 to 2020.The results reveal persistently low CIPI values(0.47-0.53)across major ecosystem types,indicating widespread vulnerability to climatic variability.Among these ecosystems,forests exhibit the highest CIPI(0.55),followed by shrublands(0.54),croplands(0.53),grasslands(0.51),and barelands(0.43).The Theil index analysis further demonstrates significant intra-group disparities,suggesting that extreme climatic events amplify CIPI heterogeneity.Moreover,the dominant environmental drivers differ among ecosystem types:the Palmer Drought Severity Index(PDSI)primarily constrains grassland productivity,solar radiation(SRAD)strongly influences shrub and cropland systems,whereas subsurface factors exert greater control in forested regions.This study provides a quantitative framework for evaluating climate-ecosystem interactions and offers a scientific basis for long-term ecological monitoring and security planning across the EQTP.
基金Supported by the China National Science and Technology Major Project(2025ZD400801)CNPC Science and Technology Major Project(2023ZZ07-01)。
文摘Based on the plate tectonics theory,the sedimentary environment of paleotectonics along the passive continental margins on both sides of the South Atlantic Ocean was reconstructed using the paleomagnetic,regional geological,and seismic data,and the intrinsic relationships of hydrocarbon distribution in the passive continental margin basins and the differential hydrocarbon accumulation patterns were analyzed.Results show that basins on both sides of the South Atlantic experienced two major extensional phases—rift and depression—and four evolutionary stages:the Early Cretaceous Berriasian-Barremian intracontinental rift stage,the Early Cretaceous Aptian-Albian intercontinental rift to initial drift transition stage,the Late Cretaceous-Paleogene drift-related marine transgressive depression stage,and the Neogene-Quaternary drift-related marine regressive depression stage.According to basin architecture and superposition style,the passive-margin basins are classified into two principal types:rift-continental marginal depression composite and continental marginal depression-dominated.The basins in the study area were further divided into six types based on the development degree of salt tectonics and the type of dominant sand bodies,i.e.salt-free rift-continental marginal gravity-flow composite type,salt-free rift-continental marginal delta composite type,salt-bearing rift-continental marginal gravity flow composite type,delta-dominated salt-bearing rift-continental marginal delta composite type,gravity-flow-dominated continental marginal depression type,and delta-dominated continental marginal depression type.The salt-free rift-continental marginal gravity flow and delta composite basins are mainly distributed in the southern segment.The salt-bearing rift-continental marginal gravity flow and delta composite basins are mainly distributed in the central segment.The gravity-flow-dominated continental marginal depression basins are mainy distributed in the northern segment.The delta-dominated passive-margin depression basins are distributed in three segments from north to south.In different types of basins,distinctive depositional systems and source-reservoir-caprock assemblages were formed in each upper/lower structure layer.The superimposition and evolution of multi-phase prototype basins result in the orderly hydrocarbon accumulation vertically and laterally,which are“segmented along-strike,zoned across-strike,and layered vertically”.
基金supported by grants from the National Key Research and Development Program of China,Stem Cell and Translational Research(2022YFA1104100,2022YFA1105000,2018YFA0801404)the National Natural Science Foundation of China(82570270,82270230,32130046,82171617,82471689,82170540,82471462,82270566)+8 种基金the Guangdong Basic and Applied Basic Research Foundation(2023B1515020119)the Key Research and Development Program of Guangdong Province(2023B1111050006)the Key Scientific and Technological Program of Guangzhou City(2023B01J1002,202206080002)the Pioneering Talents Project of the Guangzhou Development Zone(2021-L029)the Guangdong Special Support Program(2019BT02Y276)the Shenzhen Science and Technology Program(KJZD20230923114504008)the Sanming Project of Medicine in Shenzhen Nanshan(SZSM2021034008)the Science and Technology Planning Project of Gaozhou(20240619111622)the Special Funds for the Cultivation of Guangdong College Students'Scientific and Technological Innovation(pdjh2025ak003).
文摘Vaccination is the preferred strategy for preventing infections such as influenza in elderly individuals;however,its efficacy is often suboptimal due in part to age-related declines in immune function.In this study,we discovered that the infusion of mesenchymal stromal cells(MSCs)restored defects in the splenic stromal cell network and lymphocyte architecture in aged mice while also increasing specific antibody levels following vaccine immunization.This significantly protected aging mice from influenza infection.Mechanistically,the delivered MSCs localized in the splenic marginal zones,where they positioned themselves near marginal reticular cells(MRCs)and stimulated MRC proliferation,partially through the action of vascular endothelial growth factor A(VEGFA).This MSC‒MRC interaction orchestrated the reconstruction of the stromal network,thereby restoring lymphocyte homeostasis and germinal center reactions.Importantly,the MSC-mediated enhancement of the vaccine response was further validated in aged cynomolgus monkeys.Collectively,our findings provide new insights into the application of MSCs in addressing age-related immune decline and highlight splenic MRCs as critical therapeutic targets.
文摘This paper studies the context of the central area contiguous with the iron bed of medium-sized cities of the northwest region of São Paulo,in Brazil,namely:Presidente Prudente,Araçatuba,Birigüi,São Josédo Rio Preto and Marilia.Not surprisingly,the ancient boundaries of railway lines crossing the countryside regions.These urban centers were developed by the expansion of the railway,but with the deactivation of the rail transport,its core areas went into obsolescence and deterioration process and,more recently,are suffering processes of modernization and productive restructuring.At the same time,amid the industrial landscapes and decaying railroad heritage,there are situations and dweller types able to reveal some imaginary,capable of triggering:surprises,dilemmas and entanglements in the analysis of urban composition,the modernization process and its consequent deterioration.Therefore,from the marginal uses present in each city of the northwestern country towns of São Paulo,we try explain a poltical and critical point of view of these urban areas.Thus,the marginal architecture is not only the expression of subaltern subjectivities,reflecting the complexities present in emblematic areas of public importance,affected by degradation processes,but also,the attempt to define a concept strategy:a destabilizing way of reading places filled with meaning,in the counterculture of the hegemonic space to make experimental projects.
基金supported by the National Natural Science Foundation of China(No.42177184)。
文摘The Litang fault zone is an important seismogenic structure along the southeastern margin of the Tibetan Plateau.It caused the M71/4 earthquake in Litang in 1948 AD.The fault zone intersects the Sichuan-Xizang transportation corridor and poses a serious risk to its safe operation.This study,utilizing high-resolution remote sensing interpretation,field geological verification,UAV photogrammetry,UAV LiDAR,paleoearthquake trench excavation,and AMS^(14)C and OSL dating methods,reveals the geometric structure,slip rates,paleoearthquake sequence,and earthquake rupture segmentation of the Litang fault zone;analyzes the rupture distribution range of the 1729 AD Litang earthquake and estimates its magnitude.The study indicates that the Litang fault zone is a relatively immature strike-slip fault,which has developed as a new active fault zone within the Northwestern Sichuan sub-block during the southeastward material migration of the southeastern margin of the Tibetan Plateau.This reflects a transformation in the deformation model of the Northwestern Sichuan sub-block crust from the‘Rigid Block’model to the‘Continuous Deformation’model.
基金supported by the National Natural Science Foundation of China(Grant Nos.82272955 and 22203057)the Natural Science Foundation of Fujian Province(Grant No.2021J011361).
文摘The presence of a positive deep surgical margin in tongue squamous cell carcinoma(TSCC)significantly elevates the risk of local recurrence.Therefore,a prompt and precise intraoperative assessment of margin status is imperative to ensure thorough tumor resection.In this study,we integrate Raman imaging technology with an artificial intelligence(AI)generative model,proposing an innovative approach for intraoperative margin status diagnosis.This method utilizes Raman imaging to swiftly and non-invasively capture tissue Raman images,which are then transformed into hematoxylin-eosin(H&E)-stained histopathological images using an AI generative model for histopathological diagnosis.The generated H&E-stained images clearly illustrate the tissue’s pathological conditions.Independently reviewed by three pathologists,the overall diagnostic accuracy for distinguishing between tumor tissue and normal muscle tissue reaches 86.7%.Notably,it outperforms current clinical practices,especially in TSCC with positive lymph node metastasis or moderately differentiated grades.This advancement highlights the potential of AI-enhanced Raman imaging to significantly improve intraoperative assessments and surgical margin evaluations,promising a versatile diagnostic tool beyond TSCC.
基金supported by the National Natural Science Foundation of China(31600479,32371576)the Key R&D Program of Yunnan Province(202403AC100028)+1 种基金the Youth Academic and Technical Leading Talent Reserve Program in Yunnan Province(202405AC350012)the 14th Five-Year Plans of Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences(XTBG-1450101,E3ZKFF2B01).
文摘Climate change has significantly increased the frequency and severity of droughts and risk of tree death worldwide.Differences in leaf habit,plant size,and species diversity are associated with differences in the risk of drought-induced mortality,but the relative contributions of these factors to the risk of mortality are unclear.In a study of the mortality of tree and shrub species during the extreme drought of 2019 in a savanna ecosystem in Southwest China,we assessed the relative contributions of evergreen and deciduous leaf habit,plant size,and species richness and diversity to the mortality of shrubs and trees after the 2019 extreme drought.The deciduous species had significantly lower hydraulic safety margins than the coexisting evergreen species,resulting in a higher mortality risk.Additionally,species and individuals with taller canopies tended to have deeper root systems,an advantage during extreme drought that reduced mortality risk.Notably,mortality risk was largely independent of stand species richness and diversity.Overall,leaf habit and plant height were better predictors of mortality risk than species richness and diversity.These novel insights provide a better understanding of the mechanisms driving drought-induced mortality in the ecosystems with a low canopy and weak interspecific and intraspecific competition for shared resources.Leaf habit and tree size should be incorporated into hypotheses on the mechanisms underlying drought-induced tree mortality.
基金Supported by the Research Project of China National Offshore Oil Corporation(SCKY-2023-HN-3)。
文摘Based on the comprehensive analysis of data from petrology and mineralogy,well logging,seismic surveys,paleontology,and geochemistry,a detailed research was conducted on paleoenvironmental and paleoclimatic conditions,and modeling of the source rocks in the second member of the Eocene Wenchang Formation(Wen 2 Member)in the Northern Shunde Subsag at the southwestern margin of the Pearl River Mouth Basin.The Wen 2 Member hosts excellent,thick lacustrine source rocks with strong longitudinal heterogeneity and an average total organic carbon(TOC)content of over 4.9%.The Wen 2 Member can be divided into three units(I,II,III)from bottom to top.Unit I features excellent source rocks with Type I organic matters(average TOC of 5.9%)primarily sourced from lake organisms;Unit II hosts source rocks dominated by Type II2 organic matters(average TOC of 2.2%),which are originated from mixed sources dominated by terrestrial input.Unit III contains good to excellent source rocks dominated by Type II1 organic matters(average TOC of 4.9%),which are mainly contributed by lake organisms and partially by terrestrial input.Under the background of rapid subsidence and limited source supply during intense rifting period in the Eocene,excellent source rocks were developed in Wen 2 Member in the Northern Shunde Subsag under the coordinated control of warm and humid climate,volcanic activity,and deep-water reducing conditions.During the deposition of Unit I,the warm and humid climate and volcanic activity promoted the proliferation of lake algaes,primarily Granodiscus,resulting in high initial productivity,and deep-water reducing conditions enabled satisfactory preservation of organic matters.These factors jointly controlled the development and occurrence of excellent source rocks.During the deposition of Unit II,a transition from warm to cool and semi-arid paleoclimatic conditions led to a decrease in lake algaes and initial productivity.Additionally,enhanced terrestrial input and shallow-water,weakly oxidizing water conditions caused a significant dilution and decomposition of organic matters,degrading the quality of source rocks.During the deposition of Unit III,when the paleoclimatic conditions are cool and humid,Pediastrum and Botryococcus began to thrive,leading to an increase in productivity.Meanwhile,the reducing environment of semi-deep water facilitated the preservation of excellent source rocks,albeit slightly inferior to those in Unit I.The study results clarify the differential origins and development models of various source rocks in the Shunde Sag,offering valuable guidance for evaluating source rocks and selecting petroleum exploration targets in similar marginal sags.
基金Supported by the Prospective Basic Research Project of CNOOC China Limited(KJQZ-2023-2001)Major Science and Technology Project of CNOOC(KJGG2022-0103-03).
文摘Based on a set of high-resolution 3D seismic data from the northern continental margin of the South China Sea,the lithospheric structure,thinning mechanisms and related syn-rift tectonic deformation response processes in the crustal necking zone in the deepwater area of the Pearl River Mouth Basin were systematically analyzed,and the petroleum geological significance was discussed.The necking zone investigated in the study is located in the Baiyun Sag and Kaiping Sag in the deepwater area of the Pearl River Mouth Basin.These areas show extreme crustal thinned geometries of central thinning and flank thickening,characterized by multi-level and multi-dipping detachment fault systems.The necking zone exhibits pronounced lateral heterogeneity in structural architectures,which can be classified into four types of thinned crustal architectures,i.e.the wedge-shaped extremely thinned crustal architecture in the Baiyun Main Sub-sag,dumbbell-shaped moderately thinned crustal architecture in the Baiyun West Sub-sag,box-shaped weakly thinned crustal architecture in eastern Baiyun Sag,and metamorphic core complex weakly thinned crustal architecture in the Kaiping Sag.This shows great variations in the degree and style of crustal thinning,types of detachment faults,distribution of syn-rift sedimentary sequences,and intensity of magmatism.The thinning of the necking zone is controlled by the heterogeneous rheological stratification of lithosphere,intensity of mantle-derived magmatism,and deformation modes of detachment faults.The syn-rift tectonic deformation of the necking zone evolved through three phases,i.e.uniform stretching during the early Wenchang Formation deposition period,necking during the late Wenchang Formation deposition period,and hyperextension during the Enping Formation deposition period.The crustal thinning extent and architectural differentiation in these phases were primarily controlled by three distinct mechanisms,i.e.the pure shear deformation activation of pre-existing thrust faults,the simple shear deformation of crust-mantle and inter-crust detachment faults,and differential coupling of lower crustal flow and ductile domes with main detachment faults.The hydrocarbon accumulation and enrichment in the necking zone exhibit marked spatial heterogeneity.Four distinct crustal thinned architecture-hydrocarbon accumulation models were identified in this study.The hydrocarbon accumulations in the shallow part exhibit significant correlations with their deep crustal thinned architectures.The unique lithospheric structure and deformation process predominantly control the favorable hydrocarbon accumulation zones with excellent source-fault-ridge-sand configurations,which is critical to reservoir-forming.The most promising exploration targets are mainly identified on the uplift zones and their seaward-dipping flanks associated with the middle and lower crustal domes.This research provides additional insights into lithospheric thinning-breakup process at intermediate continental margins of marine sedimentary basins,being significant for guiding the deepwater petroleum exploration in the Pearl River Mouth Basin.
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.
文摘BACKGROUND Postpancreatectomy hemorrhage is one of the most severe and life-threatening complications after pancreaticoduodenectomy.We present four cases of gastrointestinal bleeding patients to clarify its appropriate treatment and prevention.CASE SUMMARY The main symptoms included black stool,hematochezia,haematemesis,blood in the nasogastric tube,and hemorrhagic shock.The mean age was 66.25 years old and the median onset time was 340 d after the surgery.The bleeding location comprised gastrointestinal anastomosis,bile duct-jejunum anastomosis,and extraluminal bleeding.The possible causes included marginal ulcer,jejunal varix,and abdominal infection.Endoscopic hemostatic clips,as well as a covered stent using angiography,were utilized to stop the bleeding and three patients survived.Only one patient died of gastrointestinal bleeding,abdominal bleeding,abdominal infection,hypovolemic shock,and disseminated intravascular coagulation.CONCLUSION Early and effective endoscopic intervention is the key to successful hemostasis in patients with gastrointestinal bleeding after pancreatoduodenectomy.
基金funded by SINOPEC Science and Technology Research Program (project Nos:P24226, P24077)Northwest Oil Field Company,SINOPEC.
文摘The Cambrian platform margin in the Tarim Basin boasts favorable source-reservoir-cap assemblages,making it a significant target for hydrocarbon exploration in ultra-to extra-deep facies-controlled for-mations.Of the three major basins in western China,Tarim is the only basin with large-scale platform margin where no exploration breakthrough has been achieved yet.This study determines the vertical and lateral differential evolution of the platform margin(in the Manxi area hereafter referred to as the Cambrian Manxi platform margin)through fine-scale sequence stratigraphic division and a segmented analysis.The platform margin can be divided into the Yuqi,Tahe,Shunbei,and Gucheng segments,from north to south,based on the development of different ancient landforms and the evolutionary process of the platform.The Yuqi and Shunbei segments exhibit relatively low-elevation ancient landforms.Both segments were in a submarine buildup stage during the Early Cambrian,resulting in overall limited scales of their reservoirs.The Gucheng segment features the highest-elevation ancient landforms and accordingly limited accommodation spaces.As a result,the rapid lateral migration of high-energy facies zones leads to the development of large-scale reservoirs with only limited thicknesses.In contrast,the Tahe segment,exhibiting comparatively high-elevation ancient landforms,is identified as the most favorable segment for the formation of large-scale reservoirs.The cap rocks of the platform margin are dominated by back-reef dolomitic flats and tight carbonate rocks formed in transgressive periods.A comprehensive evaluation of source rocks,reservoirs,and cap rocks indicates that the Tahe segment boasts the optimal hydrocarbon accumulation conditions along the platform margin.In this segment,the Shayilike Formation transgressive deposits and the high-energy mound-shoal complexes along the platform margin of the Wusonggeer Formation constitute the optimal reservoir-cap rock assemblage,establishing this segment as the most promising target for hydrocarbon exploration in the platform margin.
