Metasedimentary rocks of the Banfora belt are examined for their petrography geochemistry and genesis. The main formations are pelite metapelites sandstone, and metagraywackes. The first ones show a fine interlocking ...Metasedimentary rocks of the Banfora belt are examined for their petrography geochemistry and genesis. The main formations are pelite metapelites sandstone, and metagraywackes. The first ones show a fine interlocking layering with unclear graded bedding in the sandstone compared to the metapelites, while the metagraywackes show a clearly discordant graded bedding of light grey to light pink color. The low SiO2/Al2O3 ratios (3.67 to 6.60) suggest their low sedimentary maturity. The metapelites and sandstone-pelites show moderate Na2O/K2O values (10.13 - 22.69), indicating moderate chemical maturity;in contrast, the metagraywackes show low Na2O/K2O values (1.94 - 5.80) suggesting low chemical maturity. The metapelites, sandstone-pelites and metagraywackes have Rb/Sr ratios of 0.866 - 0.004 and 0.173 - 0.607 respectively, indicating a moderate to low degree of chemical alteration. The chemical alteration index (CIA = 58 - 83) and the plagioclase alteration index (PIA = 53 - 81) suggest weak to moderate alteration of the source rocks. This alteration is different from simple alteration as the sole control of chemical composition, but is associated with metasomatism. The metapelites sandstone shows a mixture of mafic and intermediate igneous sources, which indicates that the protoliths could be basalts and andesites, but the metagraywackes would be derived from the erosion of a mixture of andesitic to granitic rocks. The studied rocks were generated from young undifferentiated to differentiated arcs. They are of low to moderate sedimentary and chemical maturity.展开更多
This review paper presents an in-depth investigation of the modeling techniques used to study conveyor belt dryers.These techniques are classified into four categories:theoretical modeling,computational fluid dynamics...This review paper presents an in-depth investigation of the modeling techniques used to study conveyor belt dryers.These techniques are classified into four categories:theoretical modeling,computational fluid dynamics(CFD),empirical,and performance under different control strategies.Within the theoretical and CFD categories,the models are further classified as transient and steady state,as well as one-dimensional,two-dimensional,and three-dimensional.The empirical approach involves conducting experimental studies to collect moisture ratio data during the drying process and comparing it with empirical models.The methods of control are divided into classical and advanced controllers,with classical controllers including proportional-integral(PI),proportional-integral-derivative(PID),and quantitative feedback theory(QFT)controllers.Advanced controllers consist of artificial intelligence-based controllers,such as artificial neural networks(ANN),adaptive neuro-fuzzy inference systems(ANFIS),nonlinear autoregressive exogenous(NARX)models,model predictive control(MPC),and soft sensors.This review elucidated the methodologies and software employed for each modeling technique,as well as their prospective utility in industrial contexts.The utilization of theoretical and CFD methodologies is advantageous in forecasting the dynamics of complex systems.Conversely,empirical techniques serve the purpose of validating theoretical models and procuring data to facilitate model refinement.Controllers play a crucial role in the optimization of the drying process and the attainment of desired outputs.展开更多
1.Objective Three stages of Mesozoic magmatic activity have been identified in the Jiaodong area,namely early magmatic emplacement,the magmatic emplacement prior to mineralization,and magmatic activity post-mineraliza...1.Objective Three stages of Mesozoic magmatic activity have been identified in the Jiaodong area,namely early magmatic emplacement,the magmatic emplacement prior to mineralization,and magmatic activity post-mineralization,from early to late.展开更多
We report new SHRIMP zircon U-Pb ages,zircon Lu-Hf isotopic and whole rock geochemical data from Permian granitoids located in the Alxa area of Inner Mongolia,China.In combination with published geochronological and g...We report new SHRIMP zircon U-Pb ages,zircon Lu-Hf isotopic and whole rock geochemical data from Permian granitoids located in the Alxa area of Inner Mongolia,China.In combination with published geochronological and geochemical data,the granitoids in the region can be divided into two age groups:ca.285 Ma and ca.269 Ma.The granitoids of the first group are mainly composed of calc-alkaline to high-K calc-alkaline,weakly peraluminous Ⅰ-type granodiorites with ε_(Hf)(t)values of-19.6 to-4.3,which demonstrates evidence of crustal reworking;the granitoids of the second group,however,mainly consist of A-type granites that are high-K calc-alkaline to shoshonite,metaluminous to weakly peraluminous,and have high 10,000×Ga/Al ratios(2.59-3.12)and ε_(Hf)(t)values ranging from-11.3 to-2.7,all of which demonstrates a mixed crust-mantle source.We interpret the granitoids of the first group to have formed during the subduction of Central Asian oceanic crust and the second group to have formed by the asthenospheric upwelling caused by the formation of slab windows during late ocean ridge subduction.展开更多
The Belt and Road global navigation satellite system(B&R GNSS)network is the first large-scale deployment of Chinese GNSS equipment in a seismic system.Prior to this,there have been few systematic assessments of t...The Belt and Road global navigation satellite system(B&R GNSS)network is the first large-scale deployment of Chinese GNSS equipment in a seismic system.Prior to this,there have been few systematic assessments of the data quality of Chinese GNSS equipment.In this study,data from four representative GNSS sites in different regions of China were analyzed using the G-Nut/Anubis software package.Four main indicators(data integrity rate,data validity ratio,multi-path error,and cycle slip ratio)used to systematically analyze data quality,while evaluating the seismic monitoring capabilities of the network based on earthquake magnitudes estimated from high-frequency GNSS data are evaluated by estimating magnitude based on highfrequency GNSS data.The results indicate that the quality of the data produced by the three types of Chinese receivers used in the network meets the needs of earthquake monitoring and the new seismic industry standards,which provide a reference for the selection of equipment for future new projects.After the B&R GNSS network was established,the seismic monitoring capability for earthquakes with magnitudes greater than M_(W)6.5 in most parts of the Sichuan-Yunnan region improved by approximately 20%.In key areas such as the Sichuan-Yunnan Rhomboid Block,the monitoring capability increased by more than 25%,which has greatly improved the effectiveness of regional comprehensive earthquake management.展开更多
The Qinling orogenic belt in central China underwent long-term tectonic evolution during an amalgamation between the North China and South China cratons.However,intense compressional deformation and uplift erosion res...The Qinling orogenic belt in central China underwent long-term tectonic evolution during an amalgamation between the North China and South China cratons.However,intense compressional deformation and uplift erosion resulted in the transformation and disappearance of much geological record from the Qinling orogenic belt,and the tectonic evolution of this belt remains poorly constrained during the Triassic.Located in the northernmost margin of the South China Craton,the Sichuan Basin preserves the complete Triassic sedimentary succession,and can provide significant information for understanding the Triassic tectonic evolution of the Qinling orogenic belt.We present detrital zircon U-Pb dating,trace element and in situ Lu-Hf isotope data for the Middle Triassic Leikoupo Formation and the Late Triassic Xujiahe Formation samples from the eastern Sichuan Basin,South China.The detrital zircon U-Pb ages of the Leikoupo Formation show seven age clusters of 280-242,350-300,500-400,1000-800,2000-1750,2100-2000 and 2600-2400 Ma,while those of the Xujiahe Formation show five age clusters of 300-200,500-350,1050-950,2000-1750 and 2600-2400 Ma.Combined with published paleocurrent and paleogeographic data,the sediments of the Leikoupo Formation are interpreted to be sourced from the North China Craton,Yangtze Craton and North Qinling orogenic belt,and the potential main source regions of the Xujiahe Formation included the South and North Qinling orogenic belts.Provenance analysis indicates that the North Qinling orogenic belt was in inherited uplift and coeval denudation in the Middle Triassic.The proportion of the detritus formed in the South Qinling orogenic belt increases gradually from the Leikoupo to Xujiahe formations.This significant provenance change indicates that rapid tectonic uplift and extensive denudation of the South Qinling orogenic belt occurred in the early Late Triassic,which is related to the collision between the North China and South China cratons during the Triassic.展开更多
The Van Allen radiation belts are doughnut-shaped zones surrounding Earth, filled with highly energetic charged particles whose sources or loss mechanisms have been investigated for decades. As for the inner belt, cos...The Van Allen radiation belts are doughnut-shaped zones surrounding Earth, filled with highly energetic charged particles whose sources or loss mechanisms have been investigated for decades. As for the inner belt, cosmic ray albedo neutron decay(CRAND),radial diffusion, and local acceleration have been considered principal sources of electrons, whereas protons are predominantly from CRAND and solar protons. In this article, lightning-induced neutrons from Earth's upper atmosphere are suggested as a possible source of protons and electrons in the inner radiation belt. These terrestrial neutrons can contribute to the inner belt population by undergoing nuclear decay. Several approaches are proposed and discussed to evaluate the potential contribution of lightning-induced neutrons to the inner belt, including magnitude estimation, Monte Carlo simulations, and in situ observations. This article discusses some avenues of further study to determine the contribution of lightning-induced neutrons to the inner radiation belt.展开更多
Doline susceptibility mapping(DSM)in karst aquifer is important in terms of estimating the vulnerability of the aquifer to pollutants,estimating the infiltration rate,and infrastructures exposed to the development of ...Doline susceptibility mapping(DSM)in karst aquifer is important in terms of estimating the vulnerability of the aquifer to pollutants,estimating the infiltration rate,and infrastructures exposed to the development of dolines.In this research,doline susceptibility map was prepared in Saldaran mountain by generalized linear model(GLM)using 14 affecting parameters extracted from satellite images,digital elevation model,and geology map.Only 8 parameters have been inputted to the model which had correlation with dolines.In this regards,306 dolines were identified by the photogrammetric Unmanned Aerial Vehicles(UAV)method in 600 hectares of Salderan lands and then,these data were divided into the training(70%)and testing(30%)data for modelling.The results of DSM modeling showed that classified probability of doline occurrences in the Saldaran mountain were as follow:16.5%of the area high to very high,72%in the class of low to very low,and 5%in the moderate class.Also,locally,in Saldaran mountain,the Pirghar aquifer has the highest potential for the doline development,followed by Bagh Rostam and Sarab aquifers.Also,the precipitation,digital elevation model,Topographic Position Index,drainage density,slope,TRASP(transformed the circular aspect to a radiation index),Snow-Covered Days and vegetation cover index are of highest importance in the DSM modeling,respectively.Accurate evaluation of the model using the Receiver Operating Characteristics(ROC)curve represents a very good accuracy(AUC=0.953)of the DSM model.展开更多
The Yangtze River Economic Belt is the birthplace of the world s rice farming culture,and is the origin of common rice(Oryza sativa L.),wild rice(Oryza Rufipogon Griff.),medicinal rice(Oryza officinalis Wall.ex G.Watt...The Yangtze River Economic Belt is the birthplace of the world s rice farming culture,and is the origin of common rice(Oryza sativa L.),wild rice(Oryza Rufipogon Griff.),medicinal rice(Oryza officinalis Wall.ex G.Watt),and wart-grain rice(Oryza granate Nees et Arn.ex Hook.f.).Rice culture is the main theme of agricultural culture in this economic belt and an outstanding representative of excellent traditional Chinese culture.This study provides an overview of the history of rice cultivation in the belt from the prehistory,post-history and modern progress.It studies the agricultural cultural heritage resources of the whole rice industry chain from the biological genetic resources,world cultural heritage,key cultural relics protection units,national archaeological site parks,movable cultural relics,important agricultural cultural heritage,intangible cultural heritage,China time-honored brands,historical names,traditional markers,tribute culture,archival and documentary heritage.It also analyzes the six main problems in the inheritance and development of rice farming culture,and proposes 8 strategies,including promoting the inheritance and innovative development of excellent traditional Chinese culture through the inheritance of rice farming culture,promoting the Exploration of the Origins of Chinese Civilization Project through rice farming culture,and creating the Yangtze River National Cultural Park with rice farming culture as the main theme.展开更多
With the implementation of the Belt and Road Initiative, China is deepening its cooperation in oil and gas resources with countries along the Initiative. In order to better mitigate risks and enhance the safety of inv...With the implementation of the Belt and Road Initiative, China is deepening its cooperation in oil and gas resources with countries along the Initiative. In order to better mitigate risks and enhance the safety of investments, it is of significant importance to research the oil and gas investment environment in these countries for China's overseas investment macro-layout. This paper proposes an indicator system including 27 indicators from 6 dimensions. On this basis, game theory models combined with global entropy method and analytic hierarchy process are applied to determine the combined weights, and the TOPSIS-GRA model is utilized to assess the risks of oil and gas investment in 76 countries along the Initiative from 2014 to 2021. Finally, the GM(1,1) model is employed to predict risk values for 2022-2025. In conclusion, oil and gas resources and political factors have the greatest impact on investment environment risk, and 12 countries with greater investment potential are selected through cluster analysis in conjunction with the predicted results. The research findings may provide scientific decisionmaking recommendations for the Chinese government and oil enterprises to strengthen oil and gas investment cooperation with countries along the Belt and Road Initiative.展开更多
Establishing the Greater Food Approach and promoting the Yangtze River Economic Belt s national major regional development strategy can better support and serve the agricultural power and Chinese-style modernization.T...Establishing the Greater Food Approach and promoting the Yangtze River Economic Belt s national major regional development strategy can better support and serve the agricultural power and Chinese-style modernization.This paper introduces the characteristics of fruit industry in 16 autonomous prefectures and 47 autonomous counties under the jurisdiction of the Yangtze River Economic Belt.It studies the intellectual property resources of brand marks from the aspects of geographical indications,collective trademarks,certification trademarks,well-known trademarks in China and national design patents,and analyzes the main problems of brand and high-quality development of fruit industry in these ethnic autonomous areas.Finally,it puts forward some strategies,such as improving the protection of intellectual property rights of geographical indications,using intellectual property rights of brand signs,building modern seed industry upgrading project,drawing lessons from the experience of thousand villages demonstration project,ensuring that large-scale poverty does not occur,and building a diversified food supply system.展开更多
Carbon peak and carbon neutrality(dual-carbon)are important targets for the international response to climate change.The Silk Road Economic Belt is a strategic resource region and is important for future ecological en...Carbon peak and carbon neutrality(dual-carbon)are important targets for the international response to climate change.The Silk Road Economic Belt is a strategic resource region and is important for future ecological environment and tourism development.Based on the“dual-carbon”targets,the Single index quantification,Multiple index synthesis,and Poly-criteria integration evaluation model were used in this study to measure the coordinated development index of the ecological environment,public service,and tourism economy along the Silk Road Economic Belt and to analyze its spatial and temporal evolution.Further,it explores the dynamic evolution and development trend of the three systems using the Kernel Density and Grey Markov Prediction Model.The results show that the coordinated development index along this region needs to be improved during the study period.Furthermore,the coordinated development index of the Southwest region is relatively higher than that of the Northwest region.From the development trend of the three systems,all of them develop in a stable manner;however,the tourism economy system is easily affected by external disturbances.The coordinated development index of the three systems changes dynamically and tends to be in a good state of coordination.There is a certain spatial and temporal heterogeneity.The gravity center of the coordinated development index has been in the Southwest region.During the forecast period,the coordinated development index along this region will improve significantly,while insufficient and unbalanced development will continue.展开更多
The Guanpo pegmatite field in the North Qinling orogenic belt(NQB),China,hosts the most abundant LCT pegmatites.However,their emplacement conditions and structural control remain unexplored.In this contribution,we inv...The Guanpo pegmatite field in the North Qinling orogenic belt(NQB),China,hosts the most abundant LCT pegmatites.However,their emplacement conditions and structural control remain unexplored.In this contribution,we investigated it combining pegmatite orientation measurement with oxygen isotope geothermometry and fluid inclusion study.The orientations of type A1 pegmatites(P_(f)<σ_(2))are predominantly influenced by P-and T-fractures due to simple shearing in Shiziping dextral thrust shear zone during D_(2)deformation,whereas type A2 pegmatites(contemporaneous with D_(4))are governed by hydraulic fractures aligned with S_(0)and S_(0+1)stemming from fluid pressure(P_(f)<σ_(2)).Additionally,type B pegmatites(P_(f)≤σ_(2))exhibit orientations shaped by en echelon extensional fractures in local ductile shear zones(contemporaneous with D_(3)).The albite-quartz oxygen isotope geothermometry and microthermometric analysis of fluid inclusions in elbaites from the latest pegmatites(including types B and A2)suggest that the crystallization P-T for late magmatic and hydrothermal stages are 527.5-559.2℃,320℃,3.1-3.6 kbar and 2.0 kbar,respectively.Our observations along with previous studies suggest that the genesis of the LCT pegmatites was a long-term,multi-stage event during early Paleozoic orogeny(including the collision stage)of the NQB,and was facilitated by various local fractures.展开更多
Accelerating the construction of agricultural power,further promoting the high-quality development of the Yangtze River Economic Belt,and better supporting and serving Chinese-style modernization are the key issues at...Accelerating the construction of agricultural power,further promoting the high-quality development of the Yangtze River Economic Belt,and better supporting and serving Chinese-style modernization are the key issues at present.This paper first introduces the Yangtze River Economic Belt and its ethnic areas,and studies the characteristics of the grain and oil industry in the ethnic autonomous areas of the economic belt,as well as the current situation of various types of intellectual property resources,such as industrial cultural heritage,scientific and tech-nological innovation,and brand marking intellectual property.Besides,it analyzes the main problems in the high-quality development of grain and oil in the Yangtze River Economic Belt ethnic areas.Finally,it comes up with recommendations,including protecting the intellectual prop-erty rights of cultural heritage in the field of grain and oil,leading the inheritance and development of excellent traditional Chinese culture,use scientific and technological innovation intellectual property rights to promote the innovation-driven development strategy of the grain and oil in-dustry,and providing counterpart assistance to ethnic autonomous areas in the Yangtze River Economic Belt to further promote the high-quality development of the Yangtze River Economic Belt.展开更多
The Earth's electron radiation belts typically exhibit a two-belt structure.However,observations from the Van Allen Probes revealed the existence of a three-belt structure.This structure consists of an inner belt,...The Earth's electron radiation belts typically exhibit a two-belt structure.However,observations from the Van Allen Probes revealed the existence of a three-belt structure.This structure consists of an inner belt,a slot region,a remnant belt,a“second slot,”and a new outer belt(or the“third belt”).The formation of the structure involves both the partial loss of the original outer belts and the formation of the third belts.These processes are likely associated with radial diffusion induced by ultra-low-frequency(ULF)waves.In this study,we mainly analyzed electron flux data from medium Earth orbit(MEO)navigation satellites M17–M19 to supplement the observational evidence for the sub-relativistic electron(~100–500 keV)three-belt structure.Evidence of substorm injections and ULF waves during the three-belt event was identified,suggesting they played significant roles in the formation and evolution of the third belt.Substorm injections may introduce new electron populations to the third belt,whereas ULF waves may influence the evolution of the third belt through radial diffusion.Toward the end of the three-belt event,the compression of the magnetosphere by shocks may lead to the dropout of the third belt because of the magnetopause shadowing effect and outward radial diffusion,ultimately disrupting the three-belt structure.This study provides more evidence for the presence of a sub-relativistic electron three-belt structure and offers an analysis of the evolutionary mechanisms of the third belt,which may contribute to a comprehensive understanding of the electron three-belt structure in the radiation belts.展开更多
The Gangdese belt in Xizang has experienced both Jurassic subduction and Cenozoic continental collision processes, making it a globally renowned region for magmatic rocks and porphyry copper deposits. Numerous Jurassi...The Gangdese belt in Xizang has experienced both Jurassic subduction and Cenozoic continental collision processes, making it a globally renowned region for magmatic rocks and porphyry copper deposits. Numerous Jurassic intrusions have been identified in the belt. Apart from the quartz diorite porphyry in the large Xietongmen deposit, the Cu mineralization potential of other Jurassic intrusions in this belt remains unclear. This study presents zircon U–Pb dating and trace elements, apatite major and trace elements as well as published whole-rock geochemical and isotopic data of the Dongga tonalite in the central part of the Gangdese belt, aiming to reveal the petrogenesis, oxidation state, volatile content, and Cu mineralization potential of this intrusion. The Dongga tonalite has a zircon U–Pb age of 179.4 ± 0.9 Ma. It exhibits high whole-rock V/Sc values(8.76–14.6), relatively low apatite CeN/CeN*ratios(1.04–1.28), elevated zircon(Eu/Eu*)Nvalues(an average of 0.44), high Ce4+/Ce3+values(205–1896), and high ?FMQ values(1.3–3.7), collectively suggesting a high magmatic oxygen fugacity. The Dongga tonalite features amphibole phenocrysts, relatively high whole-rock Sr/Y ratios(20.3–58.9), and lower zircon Ti temperatures (502–740 ℃), reflecting a high magmatic water content. Estimation of magmatic sulfur content(0.002–0.024 wt%) based on apatite SO3contents indicates an enriched magma sulfur content. Combined with previous studies and the collected Sr–Nd–Hf isotopes, the Dongga tonalite is derived from juvenile lower crust related with subduction of the Neo-Tethys oceanic slab. When compared with Xietongmen orebearing porphyries, the Dongga tonalite exhibits remarkable similarities with the Xietongmen ore-bearing porphyries in terms of magma source, tectonic background, magmatic redox state, and volatile components, which indicates that the Dongga tonalite has a high porphyry Cu mineralization potential, and therefore, provides important guidance for the future mineralization exploration.展开更多
A COnstellation of Radiation BElt Survey(CORBES)program is proposed by the Sub-Group on Radiation Belt(SGRB)of TGCSS,COSPAR.To address the open qustions about the dynamics of the Earth’s radiation belt,CORBES mission...A COnstellation of Radiation BElt Survey(CORBES)program is proposed by the Sub-Group on Radiation Belt(SGRB)of TGCSS,COSPAR.To address the open qustions about the dynamics of the Earth’s radiation belt,CORBES mission would use a constellation of small/CubeSats to take an ultra-fast survey of the Earth’s radiation belt.The concept,science objectives and preliminary technical design of CORBES are introduced.This mission is an international multilateral cooperation mission coordinated by COSPAR.The SGRB Science Activities and COSPAR HQs Coordinate Activities on CORBES are summaried.展开更多
The energy spectrum of energetic electrons is a key factor representing the dynamic variations of Earth’s Van Allen radiation belts.Increased measurements have indicated that the commonly used Maxwellian and Kappa di...The energy spectrum of energetic electrons is a key factor representing the dynamic variations of Earth’s Van Allen radiation belts.Increased measurements have indicated that the commonly used Maxwellian and Kappa distributions are inadequate for capturing the realistic spectral distributions of radiation belt electrons.Here we adopt the Kappa-type(KT)distribution as the fitting function and perform a statistical analysis to investigate the radiation belt electron flux spectra observed by the Van Allen Probes.By calculating the optimal values of the key KT distribution parameters(i.e.,κandθ2)from the observed spectral shapes,we fit the radiation belt electron fluxes at different L-shells under different geomagnetic conditions.In this manner,we obtain typical values of the KT distribution parameters,which are statistically feasible for modeling the radiation belt electron flux profiles during either geomagnetically quiet or active periods.A comparison of the KT distribution model results with those using the Maxwellian or Kappa distribution reveals the advantage of the KT distribution for studying the overall properties of the radiation belt electron spectral distribution,which has important implications for deepening the current understanding of the radiation belt electron dynamics under evolving geomagnetic conditions.展开更多
Geodynamic mechanism responsible for the generation of Silurian granitoids and the tectonic evolution of the Qilian orogenic belt remains controversial. In this study, we report the results of zircon U–Pb age, and sy...Geodynamic mechanism responsible for the generation of Silurian granitoids and the tectonic evolution of the Qilian orogenic belt remains controversial. In this study, we report the results of zircon U–Pb age, and systematic whole-rock geochemical data for the Haoquangou and Liujiaxia granitoids within the North Qilian orogenic belt and the Qilian Block, respectively, to constrain their petrogenesis, and the Silurian tectonic evolution of the Qilian orogenic belt. Zircon U–Pb ages indicate that the Haoquangou and Liujiaxia intrusions were emplaced at423 ± 3 Ma and 432 ± 4 Ma, respectively. The Haoquangou granodiorites are calc-alkaline, while the Liujiaxia granites belong to the high-K calc-alkaline series.Both are peraluminous in composition and have relatively depleted Nd isotopic [ε_(Nd)(t) =(-3.9 – + 0.6)] characteristics compared with regional basement rocks, implying their derivation from a juvenile lower crust. They show adakitic geochemical characteristics and were generated by partial melting of thickened lower continental crust. Postcollisional extensional regime related to lithospheric delamination was the most likely geodynamic mechanism for the generation of the Haoquangou granodiorite, while the Liujiaxia granites were generated in a compressive setting during continental collision between the Qaidam and Qilian blocks.展开更多
Since the late Cenozoic,the reactivated Tianshan orogenic belt has accommodated crustal shortening exceeding 200 km,primarily due to the far-field effects of the India-Eurasia plate collision.However,the details of th...Since the late Cenozoic,the reactivated Tianshan orogenic belt has accommodated crustal shortening exceeding 200 km,primarily due to the far-field effects of the India-Eurasia plate collision.However,the details of the strain partitioning in the Tianshan Mountain range remain elusive.We interpret a new compilation of GPS velocities covering the whole Tianshan range with a classic elastic block model.Compared to previous studies with a block modeling approach,the Tianshan orogenic belt is further subdivided into several blocks based on geological fault traces and a clustering analysis approach.In addition to obvious crustal shortening on the bounding thrust faults of the Tianshan,our inverted fault slip rates also reveal that faults within the Tianshan orogenic belt,such as the Nalati Fault and the southern margin of the Issyk-Kul Lake Fault,which plays a crucial role in accommodating the tectonic crustal shortening.In the 72°E-78°E region,the internal shortening rate within the mountain is approximately 5-7 mm/yr.Besides crustal shortening,strike-slip motion occurs on faults in the interior of the mountain range as well as in the foreland fold-and-thrust belts,especially in the southern margin of the Tianshan.These findings suggest that the crustal deformation in the Tianshan Mountain range is more complex than previously thought,and the oblique convergence between the Tarim Basin and the Tianshan probably results in both strike-slip and thrust motion.展开更多
文摘Metasedimentary rocks of the Banfora belt are examined for their petrography geochemistry and genesis. The main formations are pelite metapelites sandstone, and metagraywackes. The first ones show a fine interlocking layering with unclear graded bedding in the sandstone compared to the metapelites, while the metagraywackes show a clearly discordant graded bedding of light grey to light pink color. The low SiO2/Al2O3 ratios (3.67 to 6.60) suggest their low sedimentary maturity. The metapelites and sandstone-pelites show moderate Na2O/K2O values (10.13 - 22.69), indicating moderate chemical maturity;in contrast, the metagraywackes show low Na2O/K2O values (1.94 - 5.80) suggesting low chemical maturity. The metapelites, sandstone-pelites and metagraywackes have Rb/Sr ratios of 0.866 - 0.004 and 0.173 - 0.607 respectively, indicating a moderate to low degree of chemical alteration. The chemical alteration index (CIA = 58 - 83) and the plagioclase alteration index (PIA = 53 - 81) suggest weak to moderate alteration of the source rocks. This alteration is different from simple alteration as the sole control of chemical composition, but is associated with metasomatism. The metapelites sandstone shows a mixture of mafic and intermediate igneous sources, which indicates that the protoliths could be basalts and andesites, but the metagraywackes would be derived from the erosion of a mixture of andesitic to granitic rocks. The studied rocks were generated from young undifferentiated to differentiated arcs. They are of low to moderate sedimentary and chemical maturity.
基金supported by the AmericanUniversity in Cairo,Egypt.
文摘This review paper presents an in-depth investigation of the modeling techniques used to study conveyor belt dryers.These techniques are classified into four categories:theoretical modeling,computational fluid dynamics(CFD),empirical,and performance under different control strategies.Within the theoretical and CFD categories,the models are further classified as transient and steady state,as well as one-dimensional,two-dimensional,and three-dimensional.The empirical approach involves conducting experimental studies to collect moisture ratio data during the drying process and comparing it with empirical models.The methods of control are divided into classical and advanced controllers,with classical controllers including proportional-integral(PI),proportional-integral-derivative(PID),and quantitative feedback theory(QFT)controllers.Advanced controllers consist of artificial intelligence-based controllers,such as artificial neural networks(ANN),adaptive neuro-fuzzy inference systems(ANFIS),nonlinear autoregressive exogenous(NARX)models,model predictive control(MPC),and soft sensors.This review elucidated the methodologies and software employed for each modeling technique,as well as their prospective utility in industrial contexts.The utilization of theoretical and CFD methodologies is advantageous in forecasting the dynamics of complex systems.Conversely,empirical techniques serve the purpose of validating theoretical models and procuring data to facilitate model refinement.Controllers play a crucial role in the optimization of the drying process and the attainment of desired outputs.
基金This paper was supported by the geological researchprojects of the Shandong Yantai Xintai Gold Mining Co.,Ltd.under China National Gold Group Corporation(Grant Nos.XY-DZ2020081,WTDZ2022001,XY-DZ20210161,and XY-DZ2022183)。
文摘1.Objective Three stages of Mesozoic magmatic activity have been identified in the Jiaodong area,namely early magmatic emplacement,the magmatic emplacement prior to mineralization,and magmatic activity post-mineralization,from early to late.
基金financially supported by the Geological Survey of China(Grant Nos.DD20240075,and DD20243516)the National Natural Science Foundation of China(Grant No.41872209)Basic Scientific Research Fund of the Institute of Geology,Chinese Academy of Geological Sciences(Grant No.J2314)。
文摘We report new SHRIMP zircon U-Pb ages,zircon Lu-Hf isotopic and whole rock geochemical data from Permian granitoids located in the Alxa area of Inner Mongolia,China.In combination with published geochronological and geochemical data,the granitoids in the region can be divided into two age groups:ca.285 Ma and ca.269 Ma.The granitoids of the first group are mainly composed of calc-alkaline to high-K calc-alkaline,weakly peraluminous Ⅰ-type granodiorites with ε_(Hf)(t)values of-19.6 to-4.3,which demonstrates evidence of crustal reworking;the granitoids of the second group,however,mainly consist of A-type granites that are high-K calc-alkaline to shoshonite,metaluminous to weakly peraluminous,and have high 10,000×Ga/Al ratios(2.59-3.12)and ε_(Hf)(t)values ranging from-11.3 to-2.7,all of which demonstrates a mixed crust-mantle source.We interpret the granitoids of the first group to have formed during the subduction of Central Asian oceanic crust and the second group to have formed by the asthenospheric upwelling caused by the formation of slab windows during late ocean ridge subduction.
基金supported by grants from the National Natural Science Foundation of China(No.42004010)the B&R Seismic Monitoring Network Project of the China Earthquake Networks Center(No.5007).
文摘The Belt and Road global navigation satellite system(B&R GNSS)network is the first large-scale deployment of Chinese GNSS equipment in a seismic system.Prior to this,there have been few systematic assessments of the data quality of Chinese GNSS equipment.In this study,data from four representative GNSS sites in different regions of China were analyzed using the G-Nut/Anubis software package.Four main indicators(data integrity rate,data validity ratio,multi-path error,and cycle slip ratio)used to systematically analyze data quality,while evaluating the seismic monitoring capabilities of the network based on earthquake magnitudes estimated from high-frequency GNSS data are evaluated by estimating magnitude based on highfrequency GNSS data.The results indicate that the quality of the data produced by the three types of Chinese receivers used in the network meets the needs of earthquake monitoring and the new seismic industry standards,which provide a reference for the selection of equipment for future new projects.After the B&R GNSS network was established,the seismic monitoring capability for earthquakes with magnitudes greater than M_(W)6.5 in most parts of the Sichuan-Yunnan region improved by approximately 20%.In key areas such as the Sichuan-Yunnan Rhomboid Block,the monitoring capability increased by more than 25%,which has greatly improved the effectiveness of regional comprehensive earthquake management.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFC0602704)the National Natural Science Foundation of China(Grant No.U20B6001 and 91755211).
文摘The Qinling orogenic belt in central China underwent long-term tectonic evolution during an amalgamation between the North China and South China cratons.However,intense compressional deformation and uplift erosion resulted in the transformation and disappearance of much geological record from the Qinling orogenic belt,and the tectonic evolution of this belt remains poorly constrained during the Triassic.Located in the northernmost margin of the South China Craton,the Sichuan Basin preserves the complete Triassic sedimentary succession,and can provide significant information for understanding the Triassic tectonic evolution of the Qinling orogenic belt.We present detrital zircon U-Pb dating,trace element and in situ Lu-Hf isotope data for the Middle Triassic Leikoupo Formation and the Late Triassic Xujiahe Formation samples from the eastern Sichuan Basin,South China.The detrital zircon U-Pb ages of the Leikoupo Formation show seven age clusters of 280-242,350-300,500-400,1000-800,2000-1750,2100-2000 and 2600-2400 Ma,while those of the Xujiahe Formation show five age clusters of 300-200,500-350,1050-950,2000-1750 and 2600-2400 Ma.Combined with published paleocurrent and paleogeographic data,the sediments of the Leikoupo Formation are interpreted to be sourced from the North China Craton,Yangtze Craton and North Qinling orogenic belt,and the potential main source regions of the Xujiahe Formation included the South and North Qinling orogenic belts.Provenance analysis indicates that the North Qinling orogenic belt was in inherited uplift and coeval denudation in the Middle Triassic.The proportion of the detritus formed in the South Qinling orogenic belt increases gradually from the Leikoupo to Xujiahe formations.This significant provenance change indicates that rapid tectonic uplift and extensive denudation of the South Qinling orogenic belt occurred in the early Late Triassic,which is related to the collision between the North China and South China cratons during the Triassic.
基金supported by the National Natural Science Foundation of China (No. 42225405 and No. 42350710200)。
文摘The Van Allen radiation belts are doughnut-shaped zones surrounding Earth, filled with highly energetic charged particles whose sources or loss mechanisms have been investigated for decades. As for the inner belt, cosmic ray albedo neutron decay(CRAND),radial diffusion, and local acceleration have been considered principal sources of electrons, whereas protons are predominantly from CRAND and solar protons. In this article, lightning-induced neutrons from Earth's upper atmosphere are suggested as a possible source of protons and electrons in the inner radiation belt. These terrestrial neutrons can contribute to the inner belt population by undergoing nuclear decay. Several approaches are proposed and discussed to evaluate the potential contribution of lightning-induced neutrons to the inner belt, including magnitude estimation, Monte Carlo simulations, and in situ observations. This article discusses some avenues of further study to determine the contribution of lightning-induced neutrons to the inner radiation belt.
文摘Doline susceptibility mapping(DSM)in karst aquifer is important in terms of estimating the vulnerability of the aquifer to pollutants,estimating the infiltration rate,and infrastructures exposed to the development of dolines.In this research,doline susceptibility map was prepared in Saldaran mountain by generalized linear model(GLM)using 14 affecting parameters extracted from satellite images,digital elevation model,and geology map.Only 8 parameters have been inputted to the model which had correlation with dolines.In this regards,306 dolines were identified by the photogrammetric Unmanned Aerial Vehicles(UAV)method in 600 hectares of Salderan lands and then,these data were divided into the training(70%)and testing(30%)data for modelling.The results of DSM modeling showed that classified probability of doline occurrences in the Saldaran mountain were as follow:16.5%of the area high to very high,72%in the class of low to very low,and 5%in the moderate class.Also,locally,in Saldaran mountain,the Pirghar aquifer has the highest potential for the doline development,followed by Bagh Rostam and Sarab aquifers.Also,the precipitation,digital elevation model,Topographic Position Index,drainage density,slope,TRASP(transformed the circular aspect to a radiation index),Snow-Covered Days and vegetation cover index are of highest importance in the DSM modeling,respectively.Accurate evaluation of the model using the Receiver Operating Characteristics(ROC)curve represents a very good accuracy(AUC=0.953)of the DSM model.
基金Supported by Social Science Foundation of Hubei Province(HBSKJJ20243227)Doctoral Initiation Project of Hubei University of Science and Technology(BK201819).
文摘The Yangtze River Economic Belt is the birthplace of the world s rice farming culture,and is the origin of common rice(Oryza sativa L.),wild rice(Oryza Rufipogon Griff.),medicinal rice(Oryza officinalis Wall.ex G.Watt),and wart-grain rice(Oryza granate Nees et Arn.ex Hook.f.).Rice culture is the main theme of agricultural culture in this economic belt and an outstanding representative of excellent traditional Chinese culture.This study provides an overview of the history of rice cultivation in the belt from the prehistory,post-history and modern progress.It studies the agricultural cultural heritage resources of the whole rice industry chain from the biological genetic resources,world cultural heritage,key cultural relics protection units,national archaeological site parks,movable cultural relics,important agricultural cultural heritage,intangible cultural heritage,China time-honored brands,historical names,traditional markers,tribute culture,archival and documentary heritage.It also analyzes the six main problems in the inheritance and development of rice farming culture,and proposes 8 strategies,including promoting the inheritance and innovative development of excellent traditional Chinese culture through the inheritance of rice farming culture,promoting the Exploration of the Origins of Chinese Civilization Project through rice farming culture,and creating the Yangtze River National Cultural Park with rice farming culture as the main theme.
基金the financial support from the National Natural Science Foundation of China(71934004)Key Projects of the National Social Science Foundation(23AZD065)the Project of the CNOOC Energy Economics Institute(EEI-2022-IESA0009)。
文摘With the implementation of the Belt and Road Initiative, China is deepening its cooperation in oil and gas resources with countries along the Initiative. In order to better mitigate risks and enhance the safety of investments, it is of significant importance to research the oil and gas investment environment in these countries for China's overseas investment macro-layout. This paper proposes an indicator system including 27 indicators from 6 dimensions. On this basis, game theory models combined with global entropy method and analytic hierarchy process are applied to determine the combined weights, and the TOPSIS-GRA model is utilized to assess the risks of oil and gas investment in 76 countries along the Initiative from 2014 to 2021. Finally, the GM(1,1) model is employed to predict risk values for 2022-2025. In conclusion, oil and gas resources and political factors have the greatest impact on investment environment risk, and 12 countries with greater investment potential are selected through cluster analysis in conjunction with the predicted results. The research findings may provide scientific decisionmaking recommendations for the Chinese government and oil enterprises to strengthen oil and gas investment cooperation with countries along the Belt and Road Initiative.
基金Supported by Special Soft Science Research Project for Hubei Province Science and Technology Innovation Talents and Services(2022EDA060).
文摘Establishing the Greater Food Approach and promoting the Yangtze River Economic Belt s national major regional development strategy can better support and serve the agricultural power and Chinese-style modernization.This paper introduces the characteristics of fruit industry in 16 autonomous prefectures and 47 autonomous counties under the jurisdiction of the Yangtze River Economic Belt.It studies the intellectual property resources of brand marks from the aspects of geographical indications,collective trademarks,certification trademarks,well-known trademarks in China and national design patents,and analyzes the main problems of brand and high-quality development of fruit industry in these ethnic autonomous areas.Finally,it puts forward some strategies,such as improving the protection of intellectual property rights of geographical indications,using intellectual property rights of brand signs,building modern seed industry upgrading project,drawing lessons from the experience of thousand villages demonstration project,ensuring that large-scale poverty does not occur,and building a diversified food supply system.
基金supported by the Hebei Province Cultural and Artistic Science Planning and Tourism Research Project[Grant No.HB22-ZD002].
文摘Carbon peak and carbon neutrality(dual-carbon)are important targets for the international response to climate change.The Silk Road Economic Belt is a strategic resource region and is important for future ecological environment and tourism development.Based on the“dual-carbon”targets,the Single index quantification,Multiple index synthesis,and Poly-criteria integration evaluation model were used in this study to measure the coordinated development index of the ecological environment,public service,and tourism economy along the Silk Road Economic Belt and to analyze its spatial and temporal evolution.Further,it explores the dynamic evolution and development trend of the three systems using the Kernel Density and Grey Markov Prediction Model.The results show that the coordinated development index along this region needs to be improved during the study period.Furthermore,the coordinated development index of the Southwest region is relatively higher than that of the Northwest region.From the development trend of the three systems,all of them develop in a stable manner;however,the tourism economy system is easily affected by external disturbances.The coordinated development index of the three systems changes dynamically and tends to be in a good state of coordination.There is a certain spatial and temporal heterogeneity.The gravity center of the coordinated development index has been in the Southwest region.During the forecast period,the coordinated development index along this region will improve significantly,while insufficient and unbalanced development will continue.
基金supported by the National Key R&D Program of China(Grant Nos.2021YFC2901902 and 2019YFC0605202)。
文摘The Guanpo pegmatite field in the North Qinling orogenic belt(NQB),China,hosts the most abundant LCT pegmatites.However,their emplacement conditions and structural control remain unexplored.In this contribution,we investigated it combining pegmatite orientation measurement with oxygen isotope geothermometry and fluid inclusion study.The orientations of type A1 pegmatites(P_(f)<σ_(2))are predominantly influenced by P-and T-fractures due to simple shearing in Shiziping dextral thrust shear zone during D_(2)deformation,whereas type A2 pegmatites(contemporaneous with D_(4))are governed by hydraulic fractures aligned with S_(0)and S_(0+1)stemming from fluid pressure(P_(f)<σ_(2)).Additionally,type B pegmatites(P_(f)≤σ_(2))exhibit orientations shaped by en echelon extensional fractures in local ductile shear zones(contemporaneous with D_(3)).The albite-quartz oxygen isotope geothermometry and microthermometric analysis of fluid inclusions in elbaites from the latest pegmatites(including types B and A2)suggest that the crystallization P-T for late magmatic and hydrothermal stages are 527.5-559.2℃,320℃,3.1-3.6 kbar and 2.0 kbar,respectively.Our observations along with previous studies suggest that the genesis of the LCT pegmatites was a long-term,multi-stage event during early Paleozoic orogeny(including the collision stage)of the NQB,and was facilitated by various local fractures.
基金Supported by Special Soft Science Research Project for Hubei Province Science and Technology Innovation Talents and Services(2022EDA060).
文摘Accelerating the construction of agricultural power,further promoting the high-quality development of the Yangtze River Economic Belt,and better supporting and serving Chinese-style modernization are the key issues at present.This paper first introduces the Yangtze River Economic Belt and its ethnic areas,and studies the characteristics of the grain and oil industry in the ethnic autonomous areas of the economic belt,as well as the current situation of various types of intellectual property resources,such as industrial cultural heritage,scientific and tech-nological innovation,and brand marking intellectual property.Besides,it analyzes the main problems in the high-quality development of grain and oil in the Yangtze River Economic Belt ethnic areas.Finally,it comes up with recommendations,including protecting the intellectual prop-erty rights of cultural heritage in the field of grain and oil,leading the inheritance and development of excellent traditional Chinese culture,use scientific and technological innovation intellectual property rights to promote the innovation-driven development strategy of the grain and oil in-dustry,and providing counterpart assistance to ethnic autonomous areas in the Yangtze River Economic Belt to further promote the high-quality development of the Yangtze River Economic Belt.
基金supported by the National Natural Science Foundation of China(Grant No.42274225)。
文摘The Earth's electron radiation belts typically exhibit a two-belt structure.However,observations from the Van Allen Probes revealed the existence of a three-belt structure.This structure consists of an inner belt,a slot region,a remnant belt,a“second slot,”and a new outer belt(or the“third belt”).The formation of the structure involves both the partial loss of the original outer belts and the formation of the third belts.These processes are likely associated with radial diffusion induced by ultra-low-frequency(ULF)waves.In this study,we mainly analyzed electron flux data from medium Earth orbit(MEO)navigation satellites M17–M19 to supplement the observational evidence for the sub-relativistic electron(~100–500 keV)three-belt structure.Evidence of substorm injections and ULF waves during the three-belt event was identified,suggesting they played significant roles in the formation and evolution of the third belt.Substorm injections may introduce new electron populations to the third belt,whereas ULF waves may influence the evolution of the third belt through radial diffusion.Toward the end of the three-belt event,the compression of the magnetosphere by shocks may lead to the dropout of the third belt because of the magnetopause shadowing effect and outward radial diffusion,ultimately disrupting the three-belt structure.This study provides more evidence for the presence of a sub-relativistic electron three-belt structure and offers an analysis of the evolutionary mechanisms of the third belt,which may contribute to a comprehensive understanding of the electron three-belt structure in the radiation belts.
基金supported by the National Natural Science Foundation Program of China(42102095,42362013,42363009)the Jiangxi Provincial Natural Science Foundation(20224BAB203036,20224BAB213040,20224ACB203008)the Open Research Fund Program of State Key Laboratory of Nuclear Resources and Environment,East China University of Technology(2022NRE12).
文摘The Gangdese belt in Xizang has experienced both Jurassic subduction and Cenozoic continental collision processes, making it a globally renowned region for magmatic rocks and porphyry copper deposits. Numerous Jurassic intrusions have been identified in the belt. Apart from the quartz diorite porphyry in the large Xietongmen deposit, the Cu mineralization potential of other Jurassic intrusions in this belt remains unclear. This study presents zircon U–Pb dating and trace elements, apatite major and trace elements as well as published whole-rock geochemical and isotopic data of the Dongga tonalite in the central part of the Gangdese belt, aiming to reveal the petrogenesis, oxidation state, volatile content, and Cu mineralization potential of this intrusion. The Dongga tonalite has a zircon U–Pb age of 179.4 ± 0.9 Ma. It exhibits high whole-rock V/Sc values(8.76–14.6), relatively low apatite CeN/CeN*ratios(1.04–1.28), elevated zircon(Eu/Eu*)Nvalues(an average of 0.44), high Ce4+/Ce3+values(205–1896), and high ?FMQ values(1.3–3.7), collectively suggesting a high magmatic oxygen fugacity. The Dongga tonalite features amphibole phenocrysts, relatively high whole-rock Sr/Y ratios(20.3–58.9), and lower zircon Ti temperatures (502–740 ℃), reflecting a high magmatic water content. Estimation of magmatic sulfur content(0.002–0.024 wt%) based on apatite SO3contents indicates an enriched magma sulfur content. Combined with previous studies and the collected Sr–Nd–Hf isotopes, the Dongga tonalite is derived from juvenile lower crust related with subduction of the Neo-Tethys oceanic slab. When compared with Xietongmen orebearing porphyries, the Dongga tonalite exhibits remarkable similarities with the Xietongmen ore-bearing porphyries in terms of magma source, tectonic background, magmatic redox state, and volatile components, which indicates that the Dongga tonalite has a high porphyry Cu mineralization potential, and therefore, provides important guidance for the future mineralization exploration.
文摘A COnstellation of Radiation BElt Survey(CORBES)program is proposed by the Sub-Group on Radiation Belt(SGRB)of TGCSS,COSPAR.To address the open qustions about the dynamics of the Earth’s radiation belt,CORBES mission would use a constellation of small/CubeSats to take an ultra-fast survey of the Earth’s radiation belt.The concept,science objectives and preliminary technical design of CORBES are introduced.This mission is an international multilateral cooperation mission coordinated by COSPAR.The SGRB Science Activities and COSPAR HQs Coordinate Activities on CORBES are summaried.
基金the National Natural Science Foundation of China(Grant Nos.42188101,42025404,41974186,42174188,and 42204160)the National Key R&D Program of China(Grant No.2022YFF0503700)+2 种基金the B-type Strategic Priority Program of the Chinese Academy of Sciences(Grant No.XDB41000000)the Fundamental Research Funds for the Central Universities(Grant Nos.2042022kf1016 and 2042023kf1025)the China Postdoctoral Science Foundation(Grant No.2022M722447)。
文摘The energy spectrum of energetic electrons is a key factor representing the dynamic variations of Earth’s Van Allen radiation belts.Increased measurements have indicated that the commonly used Maxwellian and Kappa distributions are inadequate for capturing the realistic spectral distributions of radiation belt electrons.Here we adopt the Kappa-type(KT)distribution as the fitting function and perform a statistical analysis to investigate the radiation belt electron flux spectra observed by the Van Allen Probes.By calculating the optimal values of the key KT distribution parameters(i.e.,κandθ2)from the observed spectral shapes,we fit the radiation belt electron fluxes at different L-shells under different geomagnetic conditions.In this manner,we obtain typical values of the KT distribution parameters,which are statistically feasible for modeling the radiation belt electron flux profiles during either geomagnetically quiet or active periods.A comparison of the KT distribution model results with those using the Maxwellian or Kappa distribution reveals the advantage of the KT distribution for studying the overall properties of the radiation belt electron spectral distribution,which has important implications for deepening the current understanding of the radiation belt electron dynamics under evolving geomagnetic conditions.
基金funded by Gansu Provincial Natural Science Foundation (Grant Numbers 21JR7RA503 and22JR5RA819)the Fundamental Research Funds for the Central Universities (Grant lzujbky-2021-ct07)+1 种基金the Key Talent Project of Gansu Province (2022-Yangzhenxi)the National Second Expedition to the Tibetan Plateau (2019QZKK0704)。
文摘Geodynamic mechanism responsible for the generation of Silurian granitoids and the tectonic evolution of the Qilian orogenic belt remains controversial. In this study, we report the results of zircon U–Pb age, and systematic whole-rock geochemical data for the Haoquangou and Liujiaxia granitoids within the North Qilian orogenic belt and the Qilian Block, respectively, to constrain their petrogenesis, and the Silurian tectonic evolution of the Qilian orogenic belt. Zircon U–Pb ages indicate that the Haoquangou and Liujiaxia intrusions were emplaced at423 ± 3 Ma and 432 ± 4 Ma, respectively. The Haoquangou granodiorites are calc-alkaline, while the Liujiaxia granites belong to the high-K calc-alkaline series.Both are peraluminous in composition and have relatively depleted Nd isotopic [ε_(Nd)(t) =(-3.9 – + 0.6)] characteristics compared with regional basement rocks, implying their derivation from a juvenile lower crust. They show adakitic geochemical characteristics and were generated by partial melting of thickened lower continental crust. Postcollisional extensional regime related to lithospheric delamination was the most likely geodynamic mechanism for the generation of the Haoquangou granodiorite, while the Liujiaxia granites were generated in a compressive setting during continental collision between the Qaidam and Qilian blocks.
基金supported by Key R&D Program of Xinjiang Uygur Autonomous Region (2020B03006-2)National Key R&D Program of China (2022YFC3003703)+1 种基金Open Fund of Wuhan,Gravitation and Solid Earth Tides (WHYWZ202215)National Observation and Research Station and State Key Laboratory of Geodesy and Earth's Dynamics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences (SKLGED2023-2-5)。
文摘Since the late Cenozoic,the reactivated Tianshan orogenic belt has accommodated crustal shortening exceeding 200 km,primarily due to the far-field effects of the India-Eurasia plate collision.However,the details of the strain partitioning in the Tianshan Mountain range remain elusive.We interpret a new compilation of GPS velocities covering the whole Tianshan range with a classic elastic block model.Compared to previous studies with a block modeling approach,the Tianshan orogenic belt is further subdivided into several blocks based on geological fault traces and a clustering analysis approach.In addition to obvious crustal shortening on the bounding thrust faults of the Tianshan,our inverted fault slip rates also reveal that faults within the Tianshan orogenic belt,such as the Nalati Fault and the southern margin of the Issyk-Kul Lake Fault,which plays a crucial role in accommodating the tectonic crustal shortening.In the 72°E-78°E region,the internal shortening rate within the mountain is approximately 5-7 mm/yr.Besides crustal shortening,strike-slip motion occurs on faults in the interior of the mountain range as well as in the foreland fold-and-thrust belts,especially in the southern margin of the Tianshan.These findings suggest that the crustal deformation in the Tianshan Mountain range is more complex than previously thought,and the oblique convergence between the Tarim Basin and the Tianshan probably results in both strike-slip and thrust motion.
