The A_(2)B_(2)O_(7)-type rare earth zirconate compounds have been considered as promising candidates for thermal barrier coating(TBC) materials because of their low sintering rate,improved phase stability,and reduced ...The A_(2)B_(2)O_(7)-type rare earth zirconate compounds have been considered as promising candidates for thermal barrier coating(TBC) materials because of their low sintering rate,improved phase stability,and reduced thermal conductivity in contrast with the currently used yttria-partially stabilized zirconia (YSZ) in high operating temperature environments.This review summarizes the recent progress on rare earth zirconates for TBCs that insulate high-temperature gas from hot-section components in gas turbines.Based on the first principles,molecular dynamics,and new data-driven calculation approaches,doping and high-entropy strategies have now been adopted in advanced TBC materials design.In this paper,the solid-state heat transfer mechanism of TBCs is explained from two aspects,including heat conduction over the full operating temperature range and thermal radiation at medium and high temperature.This paper also provides new insights into design considerations of adaptive TBC materials,and the challenges and potential breakthroughs are further highlighted for extreme environmental applications.Strategies for improving thermophysical performance are proposed in two approaches:defect engineering and material compositing.展开更多
Based on defect chemistry theory and molecular dynamics,the defect formation energy and its relationship with the mechanism of pyrochlore-fluorite phase change were investigated,so as to reveal the underlying mechanis...Based on defect chemistry theory and molecular dynamics,the defect formation energy and its relationship with the mechanism of pyrochlore-fluorite phase change were investigated,so as to reveal the underlying mechanism of high-temperature stability of pyrochlore zirconates.Results showed that with the rise of the atom mass of A,the defect formation energies decreased that meant the crystal structure tended to become more disordered.Noticeably,the first nearest cation antisite dominated the pyrochlore disorder transformation process.In addition,it was found that the diffusion of oxygen atoms was far higher than that of cations,and was increased with the temperature,thus also promoting the pyrochlore-fluorite transformation process.展开更多
Developing new high-entropy rare-earth zirconate(HE-RE_(2)Zr_(2)O_(7))ceramics with low thermal conductivity is essential for thermal barrier coating materials.In this work,the average atomic spacings,interatomic forc...Developing new high-entropy rare-earth zirconate(HE-RE_(2)Zr_(2)O_(7))ceramics with low thermal conductivity is essential for thermal barrier coating materials.In this work,the average atomic spacings,interatomic forces,and average atomic masses of 16 rare-earth elements occupying the A site of the cubic A_(2)B_(2)O_(7) crystal structure were calculated by density functional theory.These three physical qualities,as vectors,characterize the corresponding rare-earth elements.The distance between two vectors quantitatively describes the difference between two rare-earth elements.For greater differences between two rare-earth elements,the disorder degree of HE-RE_(2)Zr_(2)O_(7)is greater,and therefore,the thermal conductivity is lower.According to the theoretical calculations,the thermal conductivity of the ceramics gradually increases in the order of(SC_(0.2)Y_(0.2)La_(0.2)Ho_(0.2)Yb_(0.2))_(2)Zr_(2)0_(7),(SC_(0.2)Ce_(0.2)Nd_(0.2)Eu_(0.2)Gd_(0.2))_(2)Zr_(2)0_(7),(SC_(0.2)Y_(0.2)Tm_(0.2)Yb_(0.2)Lu_(0.2))_(2)Zr_(2)0_(7),and(Sc_(0.2)Er_(0.2)Tm_(0.2)Yb_(0.2)Lu_(0.2))_(2)Zr_(2)O_(7).Using the solution precursor plasma spray method and pressureless sintering method,four types of HE-RE2Zr2Oz powder and bulk samples were prepared.The samples all showed a single defective fluorite structure with a uniform distribution of the elements and a stable phase structure.The thermal conductivities of the sintered HE-RE_(2)Zr_(2)0_(7) bulk samples ranged from 1.30 to 1.45 Wm^(-1).K^(-1) at 1400℃,and their differences were consistent with the theoretical calculation results.Among the ceramics,(Sc_(0.2)Y_(0.2)La_(0.2)Ho_(0.2)Yb_(0.2))_(2)Zr_(2)O_(7) had the lowest thermal conductivity(1.30 W·m^(-1)·K^(-1),1400℃),highest thermal expansion coefficient(10.19×10^(-6) K^(-1),200-1400℃),highest fracture toughness(1.69±0.28 MPa·m^(1/2)),and smallest brttleness index(3.03μm^(1/2)).Therefore,(Sc_(0.2)Y_(0.2)La_(0.2)Ho_(0.2)Yb_(0.2))_(2)Zr_(2)0_(7)is considered to be an ideal candidate material for next-generation thermal barrier coating applications.展开更多
Ultrafine-grained(Sm_(0.2)Gd_(0.2)Dy_(0.2)Er_(0.2)Yb_(0.2))_(2)Zr_(2)O_(7)high-entropy zirconates with single fluorite structure have been fabricated by high-pressure sintering of the self-synthesized nanopowders for ...Ultrafine-grained(Sm_(0.2)Gd_(0.2)Dy_(0.2)Er_(0.2)Yb_(0.2))_(2)Zr_(2)O_(7)high-entropy zirconates with single fluorite structure have been fabricated by high-pressure sintering of the self-synthesized nanopowders for the first time.The as-sintered samples exhibit a good microstructure with a grain size of 220 nm and a relative density of 96.8%,which yield excellent comprehensive mechanical properties with a high Vickers hardness of 12.5 GPa and a high fracture toughness of 3.4 MPa·m1/2.In addition,the as-sintered samples possess a good thermostability with the grain growth rate of 30 nm/h,and a low thermal conductivity of 1.57 W·m^(-1)·℃^(-1)at room temperature.The superior mechanical and thermal properties are primarily attributed to the“high-entropy”and grain-refinement effects and good interface bonding.展开更多
The Jiuyishan granitic complex,located in the Nanling Range,South China,is composed of five granitic plutons(Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan).Zircon U-Pb dating of four plutons(Jinjiling,Pangxiemu,...The Jiuyishan granitic complex,located in the Nanling Range,South China,is composed of five granitic plutons(Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan).Zircon U-Pb dating of four plutons(Jinjiling,Pangxiemu,Shaziling and Xishan)yielded similar ages of approximately 153 Ma,indicating indistinguishable ages within error.Three plutons except the Shaziling pluton,have consistentε_(Nd)(t)(-7.8 to-5.8)andε_(Hf)(t)(-9.1 to-2.2)values,which are similar to those of the lower crustal granulitic metasedimentary and meta-igneous rocks in South China.Compared to other three plutons,the Shaziling pluton has consistentε_(Nd)(t)(-7.4 to-6.8)andε_(Hf)(t)(-7.5 to-4.7)values and shows similar source,but the Shaziling mafic microgranular enclaves(MMEs)show variableε_(Hf)(t)(-14.2 to 4.8)values,indicating a remarkable mantle magma injection of the Shaziling pluton.Zircon Ce/Sm-Yb/Gd,whole-rock CaO-P_(2)O_(5)and CaO-TiO_(2)linear trends reveal that from the Xishan to the Shaziling and from the Jinjiling to the Pangxiemu granites,they experienced apatite and titanite fractionation,respectively.Zircon Th,U,Nb,Ta,Hf,Ti,Y,P and rare earth element(REE)contents and whole-rock Sr,Ba and Rb contents also show that the Shaziling,Xishan,Jinjiling and Pangxiemu granites followed a discontinuous evolutionary series,but the Pangxiemu granites exhibit highly evolved nature.Four main controlling factors of W-Sn and rare metal mineralization in granitic rocks were discussed,and we found that the mineralization in Jiuyishan granitic complex was mainly controlled by the fractionation degree and crystallization temperature,but were rarely affected by oxygen fugacity and mantle material input.The Pangxiemu granites show particularly higher Rb and Ta contents than the other three plutons,implying that the ore deposits developed in the Jiuyishan Complex were directly related to the most evolved Pangxiemu pluton,with the occurrence of Rb and Ta as the most likely rare metal mineralization in the Jiuyishan District.A crystal mush model is proposed to interpret the petrogenetic and mineralizing processes of the Jiuyishan granitic complex.展开更多
The Ordos Basin(OB)in the western part of the North China Craton(NCC),was located at the jointed area of multi-plates and has recorded the Mesozoic tectonic characteristics.Its tectonic evolution in the Mesozoic is si...The Ordos Basin(OB)in the western part of the North China Craton(NCC),was located at the jointed area of multi-plates and has recorded the Mesozoic tectonic characteristics.Its tectonic evolution in the Mesozoic is significant to understand the tectonic transformation of the northern margin of the NCC.In this work,the detrital zircon and apatite(U-Th)/He chronological system were analyzed in the northern part of the OB,and have provided new evidence for the regional tectonic evolution.The(U-Th)/He chronological data states the weighted ages of 240‒235 Ma,141 Ma with the peak distribution of 244 Ma,219 Ma,173 Ma,147‒132 Ma.The thermal evolution,geochronological data,and regional unconformities have proved four stages of regional tectonic evolution for the OB and its surroundings in the Mesozoic:(1)The Late Permian-Early Triassic;(2)the Late Triassic-Early Jurassic;(3)the Late Jurassic-Early Cretaceous;(4)the Late Cretaceous-Early Paleogene.It is indicated that the multi-directional convergence from the surrounding tectonic units has controlled the Mesozoic tectonic evolution of the OB.Four-stage tectonic evolution reflected the activation or end of different plate movements and provided new time constraints for the regional tectonic evolution of the NCC in the Mesozoic.展开更多
When interpreting results,it is imperative to have some understanding of the degree to which the results are replicable.If the results cannot be replicated with independent data,then interpretations from the results b...When interpreting results,it is imperative to have some understanding of the degree to which the results are replicable.If the results cannot be replicated with independent data,then interpretations from the results become questionable.To minimize the potential for misinterpretations,the current study analyzes six time-series derived from globally sampled U-Pb zircon databases–of which,two are independent igneous databases,one being a quasi-independent igneous database,and three being independent detrital databases.These time-series are then analyzed with standard statistical methods to evaluate replicability.The methods include bandpass filtering to transform the raw time-series into stationary sequences,Student’s t-test,Monte Carlo simulations,periodograms from spectral analysis,correlation studies,and correlograms.Each test is designed to determine the replicability of a specific time-series,as well as the replicability of periodicities found from the time-series.The results show at least three key components to assessing replicability:(a)U-Pb igneous and detrital zircon age distributions are highly replicable,(b)time-series replicability gradually deteriorates with age,and(c)replicability is scale dependent,with low frequency cycles being more replicable than high frequency cycles.From the tests,we conclude that four harmonic cycles are highly replicable and statistically significant,these being periodicities of 810,270,90,and 67.5-myr.展开更多
The Tongshan porphyry Cu deposit is well known as one of the most economically significant porphyry deposits in northeast China.Recently,Tongshan has become the largest porphyry Cu deposit in northeast China with the ...The Tongshan porphyry Cu deposit is well known as one of the most economically significant porphyry deposits in northeast China.Recently,Tongshan has become the largest porphyry Cu deposit in northeast China with the successful exploration of the concealed ore zone V.Ore zone V has the largest Cu tonnage(562 Mt@0.50% Cu)and extends into the eastern segment at Tongshan.Compared with ore zones I-III,which are hosted within granitic rocks in the western segment,the ore zone V mainly occurs in Duobaoshan volcanic rocks and the roof pendants of newly discovered intrusions.Here,we conducted a study of the understudied eastern ore zone and found that copper mineralization is associated with the newly discovered suites in the eastern segment at Tongshan.Two periods of ore-bearing quartz veins with different widths have been recognized,including quartz-chalcopyrite-pyrite veinlets(0.1-0.2 cm)and quartz-chalcopyrite-polymetallic sulfide wide veins(>0.5 cm).The latter veins can be divided into four stages(I-IV)of mineralization and alteration,which are closely related to the newly discovered granodiorite and dacite porphyry.Our new zircon U-Pb ages show that the granodiorite and dacite porphyry were developed between 228-223 Ma,suggesting that the overprinting porphyry copper mineralization occurred in the Triassic.The Triassic suites have adakite-like character with high Sr/Y,and show no or minimal negative Eu anomalies,indicating early dominant amphibole with limited plagioclase fractionation.For the Triassic intrusions,the high zircon Eu/Eu*(0.67-0.89),Δ_(FMQ)(1.04±0.53;whereΔ_(FMQ)is the log fO_(2)difference between the sample value and the fayalite-magnetite-quartz mineral buffer),hygrometer values(∼7.19 wt.% H_(2)O)and high whole-rock Fe_(2)O_(3)/FeO,Sr/Y,V/Sc and 10,000×(Eu/Eu*)/Y ratios together indicate the Triassic magmas were oxidized and hydrous.These contents and ratios of the Triassic suites are significantly higher than those of the Ordovician suites(Δ_(FMQ)=0.74±0.26,∼5.90 wt.%H_(2)O),suggesting that the newly discovered Triassic magmas are more oxidized and hydrous,with high potential for porphyry copper mineralization.Based on the investigation of mineralization and the above results,we proposed that multiple superimposed mineralizations can help form a large-scale deposit and the southeastern segment is a favorable exploration area at Tongshan.展开更多
TiAl alloys were melted in BaZrO_(3)crucibles without and with Y addition at 1550℃for 5,10,and 15 min,respectively.The effect of the melting time and Y addition on the interaction between the crucibles and the alloys...TiAl alloys were melted in BaZrO_(3)crucibles without and with Y addition at 1550℃for 5,10,and 15 min,respectively.The effect of the melting time and Y addition on the interaction between the crucibles and the alloys was investigated.Results revealed that the interaction extent was intensified with the increasing melting time.However,it could be effectively suppressed by adding Y into the alloy due to the in situ generated Y_(2)O_(3)protection layer.The thickness of the interaction layer could be decreased from 95.6 to 25.1μm with Y addition at 1550°C for 15 min.In addition,a significant deoxidation effect was achieved by adding Y,and the O concentration of the alloy was decreased from 0.2 to 0.0561 wt.%.In comparison with Al_(2)O_(3),MgO,CaO,and Y_(2)O_(3)crucibles,BaZrO_(3)crucible combined with Y addition exhibited the lowest O contamination to the alloy melt.展开更多
The Shuangjianzishan deposit is a typical magmatic-hydrothermal deposit located in the southern Great Xing'an Range.Recent investigations have identified significant copper and tin mineralization at depth within t...The Shuangjianzishan deposit is a typical magmatic-hydrothermal deposit located in the southern Great Xing'an Range.Recent investigations have identified significant copper and tin mineralization at depth within the Shuangjianzishan deposit;however,the coupling relationship between magmatic emplacement and mineralization processes remains debated.This study presents whole-rock geochemistry,zircon LA-ICP-MS U-Pb dating,and zircon Hf isotope analyses of granite from the northern Shuangjianzishan deposit.The analysis results indicate the granite crystallized between 252.3 and 257.9 Ma,corresponding to Late Permian magmatic activity.The granite displaysε_(Hf)(t)=5.95-14.87,and t_(DM2)=333-900 Ma.Geochemically,the granite is rich in Si and Al,with high K,classified as a calc-alkaline,weakly peraluminous rock.LREEs are enriched,while HREEs are depleted,and a slight negative Eu anomaly,all of which are consistent with A-type granite characteristics.The Hercynian granite in the Shuangjianzishan deposit formed during the latter or post-collisional stages of the collision orogeny following the closure of the Paleo-Asian Ocean in the late Paleozoic era.The material source indicates a mixed origin,involving both crust and mantle contributions.The granite is also enriched in Cu,Pb,and Zn,suggesting its potential role as an ore-forming material source for the Shuangjianzishan deposit.This study proposes a potential link between Hercynian magmatism and mineralization at the Shuangjianzishan deposit for the first time,suggesting that multistage metallogenesis may be a response to successive magmatic events from Hercynian to Yanshanian periods in the mining area.展开更多
Lower Carboniferous clastic sedimentary rocks(i.e.,the Nanduan Formation)in the Changning-Menglian belt of the southeastern Tibetan Plateau may provide new insights into the tectonic evolution of the Paleo-Tethys Ocea...Lower Carboniferous clastic sedimentary rocks(i.e.,the Nanduan Formation)in the Changning-Menglian belt of the southeastern Tibetan Plateau may provide new insights into the tectonic evolution of the Paleo-Tethys Ocean.This paper presents new petrographic,geochemical,and detrital zircon U-Pb age data to constrain the provenance and depositional setting of these rocks.Sandstone samples of the Nanduan Formation are all quartz arenites(Q_(92-99)F_(1-7)L_(0-2))with high SiO_(2)contents(85.1 wt.%-95.2 wt.%;average=90.9 wt.%),indicating high compositional maturity.They exhibit fractionated rare earth element(REE)patterns,with light REE enrichment[(La/Yb)_(N)=6.48-12.1]and negative Eu anomalies(Eu/Eu^(*)=0.53-0.74),and marked negative Sr-Cs-V-Cr-Ni anomalies in upper continental crust-normalised multi-element diagrams.The geochemical features and heavy mineral assemblages suggest that sediments were mainly derived from ancient sedimentary rocks in cratonic interiors or stable continental areas,and were probably deposited in a passive continental margin setting.Detrital zircon U-Pb dating(n=256)of the Nanduan Formation sandstones defines three distinct age peaks in the Pan-African(600-500 Ma),younger Grenvillian(950-850 Ma),and older Grenvillian(1250-1000 Ma).Their zircon age spectra are similar to those of Lower Paleozoic sedimentary rocks(i.e.,the Mengtong and Mengdingjie groups)in the BaoshanSibumasu Block,but significantly different from those of older rocks in the Simao-Indochina and other surrounding blocks(i.e.,the western Yangtze,western Cathaysia,western Qiangtang,Tethyan Himalaya,and Lhasa blocks).This suggests that the Nanduan Formation was deposited at the margin of the Baoshan-Sibumasu Block.Combining the new data presented in this study with published data,we suggest that the Nanduan Formation and underlying Lancang Group were deposited in the same setting during the Early and Late Paleozoic,respectively.展开更多
The Cenozoic source-to-sink history of the Qaidam Basin is crucial for understanding of the basin-filling architecture,mountain-building processes and even the dynamics of the Tibetan Plateau growth.However,the proven...The Cenozoic source-to-sink history of the Qaidam Basin is crucial for understanding of the basin-filling architecture,mountain-building processes and even the dynamics of the Tibetan Plateau growth.However,the provenance history of Cenozoic strata in the Qaidam Basin remains ambiguous,especially in the northern Qaidam Basin.This controversy highlights the importance of obtaining the spatial source-to-sink relationships between the Qaidam Basin and its surrounding mountain ranges.In this study,we investigated the detrital zircon U-Pb ages of modern fluvial systems draining the East Kunlun Mountain.Their detrital zircon age distributions fall into five age groups:300-190,530-360,1000-560,2000-1100 and 2650-2000 Ma.The dominant age groups are 530-360 and 300-190 Ma,which represent the successive subduction of the Proto-Tethys and PaleoTethys Oceans and the subsequent continental collisions,respectively.Combining these new detrital zircon U-Pb ages with available age datasets,we finally obtained complete detrital zircon age information for modern fluvial systems in the whole Qaidam Basin.The U-Pb age distributions of modern river sands reveal that the zircon age signature of basement rocks in the East Kunlun Mountain is significantly different from that in the South Qilian Mountain but is similar to that in the Altyn Tagh Mountain.Moreover,these zircon age observations were confirmed by the significant difference in the Nd isotopic signature of modern river sands,which reveals a significant difference between the East Kunlun Mountain and South Qilian Mountain in the formation and evolution process.展开更多
Detrital zircon geochronology is reported from the c.1200 m thick Cambro-Ordovician sedimentary succession recovered in core from the COSC-2 continental drilling project in the Scandinavian Caledonides.Above a regolit...Detrital zircon geochronology is reported from the c.1200 m thick Cambro-Ordovician sedimentary succession recovered in core from the COSC-2 continental drilling project in the Scandinavian Caledonides.Above a regolith marking the sub-Cambrian peneplain,a lower to middle Cambrian(?)succession comprises conglomerate,sandstone and shale overlain by gravity flows fining upwards into the Alum Shale Formation.First results of detrital zircon geochronology from the Cambrian(?)succession show that the basal section of the autochthonous cover is characterized by mainly late Paleoproterozoic–early Mesoproterozoic detrital grains.The middle part of the succession is dominated by late Paleoproterozoic detritus with minor Mesoproterozoic and Archean input.The upper part of lower Cambrian(?)succession is characterized by Archean to Cambrian detritus.The maximum depositional age is calculated to 530.5±4 Ma for the upper part of the lower Cambrian succession.Two samples from the Lower Ordovician(?)succession above the Alum Shale Formation show predominantly Mesoproterozoic to early Neoproterozoic(1.5–0.9 Ga)ages.The autochthonous lower Cambrian(?)passive margin succession in the lower section is dominated by local detritus,sourced exclusively from the Eastern Segment of the Sveconorwegian Orogen,which includes the basement studied in COSC-2.Up-section,the provenance shifts towards the Transscandinavian Igneous Belt and Svecofennian Orogen sources,with the youngest part of the succession showing a notable input of Neoproterozoic–Cambrian active margin detritus.The Ordovician(?)succession is characterized by populations,likely derived from the Sveconorwegian Orogen,and a minor cratonic contribution.Statistical analysis of detrital zircon datasets across Baltica suggests that the Southern Baltica/Sandomirian Arc,rather than the Timanian Orogen,was a significant source of detrital material across the paleocontinent.The influence of Timanian Orogen grains is limited to northernmost Scandinavia,whereas Sandomirian detritus reached central Scandinavia in the lower to middle Cambrian and remained prevalent in southern Scandinavia into the Lower Ordovician.展开更多
The Southwest Tianshan is the suture zone between the Central Tianshan and the Tarim Craton.To better illustrate the subduction polarity of the Southwest Tianshan Ocean,a systematic detrital zircon LA-ICP-MS U-Pb geoc...The Southwest Tianshan is the suture zone between the Central Tianshan and the Tarim Craton.To better illustrate the subduction polarity of the Southwest Tianshan Ocean,a systematic detrital zircon LA-ICP-MS U-Pb geochronology of sedimentary rocks of the Devonian Apadaerkang Formation and the Carboniferous Akeqiayi Group of the Biedieli area in the Wushi region is the focus.Detrital zircon ages indicate that the youngest grains of the targeted quartz sandstones are Late Devonian and Early Carboniferous in age,respectively.These ages also have relatively similar age spectra,indicating a similar tectonic setting and source in the Biedieli area during the Devonian to Carboniferous.The main spectrum peaks occur at 2360,1960,810,640 and 440 Ma,with a principal age peak in the early Paleozoic(474-430 Ma),and the Central Tianshan Terrane is indicated as the main source.The detrital zircon geochronology and sedimentary characteristics of the Biedieli rocks indicate that the Paleozoic sedimentary rocks in the northern Wushi region were formed at an active continental margin,associated mainly with the early Paleozoic subduction of the South Tianshan Ocean.展开更多
The tectonic evolution of Borneo and the affiliation between Southern and Northern Borneo remains unclear.The Rajang and Crocker Fan sediments,as one of the largest ancient submarine fans in Southeast Asia have witnes...The tectonic evolution of Borneo and the affiliation between Southern and Northern Borneo remains unclear.The Rajang and Crocker Fan sediments,as one of the largest ancient submarine fans in Southeast Asia have witnessed the tectonic evolution of Borneo since at least the late Mesozoic.In this study,we present laser ablation inductively coupled plasma mass spectrometer(LA-ICP-MS)U-Pb dating and Hf isotopic results of detrital zircons from the Trusmadi and Crocker formations within the Crocker Fan of Sabah,Northern Borneo.Our results,coupled with previous data,show that the Crocker Fan sediments in Sabah of Northern Borneo display similar age spectra to the Rajang Fan sediments in Sarawak of Central Borneo,with two major age clusters at 130-80 and 280-200 Ma.Further provenance analysis based on mineral shape with a prismatic characteristic and similar detrital zircon Hf isotopes of the two formations illustrates that the Jurassic-Cretaceous and partly Triassic detrital zircons of the Crocker and Rajang Fan sediments were derived from the erosion of contemporaneous magmatic rocks;part of Permian-Triassic ones could be the recycling of the Jurassic deposits in SW Borneo.The initial provenance of these Permian-Triassic detritus could be synchronous magmatic rocks in the Tin belt of the Malay Peninsula.Combining with previous data,we propose that the entire Borneo continent,including both Southern and Northern Borneo,developed a common Mesozoic continental magmatic arc.Moreover,we postulate that the Rajang and Crocker fans formed in a fore-arc extensional rift basin related to the retreat of the subducted Paleo-Pacific Plate beneath the Northern Borneo margin.展开更多
Detrital zircon and apatite U-Pb-Hf isotope and trace element analyses of the late Mesoproterozoic to early Neoproterozoic strata in southern Jilin provide detailed information on the sediment provenance and tectonic ...Detrital zircon and apatite U-Pb-Hf isotope and trace element analyses of the late Mesoproterozoic to early Neoproterozoic strata in southern Jilin provide detailed information on the sediment provenance and tectonic setting of the northeastern margin of the North China Craton(NCC).Here,we present U-Pb and Lu-Hf analyses of 712 detrital zircons,and U-Pb analyses of 347 detrital apatites from the Baifangzi,Diaoyutai and Qiaotou formations.The Baifangzi and Diaoyutai formations are dominated by Neoarchean(2.5-2.6 Ga)and Paleoproterozoic(1.8-1.9 Ga)zircons,indicating a predominant NCC provenance.The Qiaotou Formation is dominated by Mesoproterozoic(1.5-1.7 Ga and 1.1-1.3 Ga)zircons with mainly positiveεHf(t)values,which are similar to those from eastern Laurentia,implying a significant provenance transition.The detrital apatite age spectra of the Baifangzi and Diaoyutai Formations show major populations at 1.8-1.9 Ga and 1.1-1.3 Ga.Based on their trace element compositions,the Mesoproterozoic apatites were mainly sourced from metamorphic rocks,indicating regional metamorphism occurred in the NCC during 1.1-1.3 Ga.Combining these data with regional studies,we propose that the NCC was adjacent to eastern Laurentia during the assembly of the Rodinia supercontinent.展开更多
The Ediacaran Period records a significant turning point in the evolution of life on Earth,witnessing the rise to ecological dominance of macroscopic tissue-grade organisms.The Wenghui biota from the Doushantuo Format...The Ediacaran Period records a significant turning point in the evolution of life on Earth,witnessing the rise to ecological dominance of macroscopic tissue-grade organisms.The Wenghui biota from the Doushantuo Formation of South China hosts abundant multicellular algal macrofossils and problematica,some of which might be closely related to taxa from classic Late Ediacaran assemblages from South Australia and the White Sea biota of Russia.However,a lack of well-resolved isotopic age estimates has hampered efforts to constrain the timing of appearance of the Wenghui biota,obfuscating its significance to our understanding of Ediacaran macroevolution in the aftermath of the Snowball Earth events.Here,we present the first SHRIMP zircon U-Pb dating results for samples obtained from a laminated tuff ash layer at the base of the Wenghui biota in the Doushantuo Formation,Jiangkou County,Tongren City,Guizhou Province,China.Our analyses yield an age of 595.4±5.3 Ma for the first appearance of Wenghui biota,suggesting that its appearance postdated that of the Lantian and Weng'an biotas,but preceded that of the Miaohe biota.These newly obtained age proxies offer an independent test of previous isotopic estimates for the age of the Wenghui biota,providing new chronostratigraphic evidence to map the succession of Ediacaran fossil assemblages on the Yangtze Platform during the Doushantuo interval.These data suggest that the Lantian,Weng'an,Wenghui,and Miaohe biotas may record a sequence of biotic assemblages attesting to successive phases in the radiation of Ediacaran macroscopic organisms,particularly macroalgae.展开更多
The Ning-Wu Basin is an important part of the Middle-Lower Yangtze River Metallogenic Belt in eastern China.It contains well-preserved Mesozoic volcanic sequences that document significant geodynamic evolution.However...The Ning-Wu Basin is an important part of the Middle-Lower Yangtze River Metallogenic Belt in eastern China.It contains well-preserved Mesozoic volcanic sequences that document significant geodynamic evolution.However,uncertainties surrounding the ages of eruptions and the temporal relationships between the four main volcanic cycles—the Longwangshan,Dawangshan,Gushan and Niangniangshan formations—have hindered our understanding of magmatic pulsation and its connection to iron mineralisation.Here,high-precision LA-ICP-MS zircon U-Pb dating of four fresh volcanic samples(one per formation)reveals weighted mean ages of 132.3±1.0 Ma(Longwangshan;MSWD=1.3),130.4±1.6 Ma(Dawangshan;MSWD=1.3),128.1±1.9 Ma(Gushan;MSWD=2.0)and 127.2±1.1 Ma(Niangniangshan;MSWD=0.23).These dates constrain volcanic activity to the Early Cretaceous Valanginian-Hauterivian interval and show a systematic trend of increasingly younger ages spanning~8 Ma(133-125 Ma).This magmatism can be subdivided into three phases:initiation(133-132 Ma),peak activity(132-130 Ma)and cessation(128-125 Ma).The episodic volcanism correlates with the accelerating rollback of the Pacific subduction zone,which drives crustal melting and asthenospheric upwelling.Notably,these cycles supplied the thermal energy,fluids and iron-rich melts that were essential for the formation of porphyritic iron deposits in the basin.By establishing a highresolution chronostratigraphic framework,this study sheds light on the spatiotemporal evolution of the Ning-Wu Basin,elucidating the coupling between crust-mantle dynamics,volcanic cyclicity and ore-forming processes across eastern China’s metallogenic belt.展开更多
The ocean crust remnants of the Proto-Tethys were preserved as the Kudi ophiolites in the West Kunlun Orogenic Belt(WKOB),and its evolutionary history was mainly constructed by research on igneous or metamorphic rocks...The ocean crust remnants of the Proto-Tethys were preserved as the Kudi ophiolites in the West Kunlun Orogenic Belt(WKOB),and its evolutionary history was mainly constructed by research on igneous or metamorphic rocks in the WKOB.Sedimentary rocks in the WKOB received little attention in the past;however,they could provide important constraints on the evolution of the oceanic lithosphere.Here,a series of shales and greywackes found in the Kudi area of WKOB were studied to constrain their deposition ages and explore their significance in the evolution of the ProtoTethys oceanic crust.The U-Pb dating and europium anomaly(Eu/Eu^(*))were analyzed for detrital zircons from greywackes interlayers,while bulk rare earth elements and yttrium(REY)of the shales were measured.Detrital zircons U-Pb ages yield a maximum deposition age of 436 Ma for the greywackes and black shales,while the REY distribution patterns of the black shales are similar to those of the Tarim Ordovician Saergan shales.Accordingly,the studied WKOB black shales were deposited in the Proto-Tethys Ocean during the Late Ordovician-Early Silurian period.The maximum deposition age at 436 Ma may represent a minimum closure time of the Proto-Tethys Ocean,which is also supported by the absence of increases in Eu/Eu^(*)values during the Late Ordovician-Early Silurian.Besides,our Eu/Eu^(*)values in detrital zircons indicate diminished orogenesis during the Archean to Meso-Proterozoic,subduction-related accretion at the margins of the supercontinent Rodinia during the Neoproterozoic.展开更多
Deciphering high-pressure granulite-facies metamorphism and anatexis within a collisional orogeny can provide crucial constraints on geodynamic evolution and melt activity during subduction and exhumation.Combining pe...Deciphering high-pressure granulite-facies metamorphism and anatexis within a collisional orogeny can provide crucial constraints on geodynamic evolution and melt activity during subduction and exhumation.Combining petrographic observations,mineral chemistry,REE in Grt-Cpx thermobarometry,and previous work,at least four stages are suggested for the metamorphic evolution of the mafic granulites in the South Altun,including the protolith stage,the high-pressure granulite-facies stage(909-1037℃and 17.3-30 kbar),medium-pressure granulite-facies overprint(9.1-11.9 kbar and 753-816℃),and subsequent late amphibolite-greenschist-facies metamorphism.Zircon U-Pb dating shows that the mafic granulites underwent high-pressure granulite-facies metamorphism at 497.2±3.7 Ma,while the leucosome formed at 498.2±2.9 Ma.Thus,the leucosomes from the host mafic granulite may have been formed at the high-pressure granulite-facies metamorphic event.The characteristics of zircon morphology,mineral inclusions,low Th/U values,HREE enrichment,and negative Eu anomalies indicate that these zircons from the leucosome were formed from the metamorphic melts.The characteristics of whole-rock major and trace elements as well as Hf isotopic features of zircons between the leucosomes and the host mafic granulite indicate that the melt may have been generated by the partial melting of the host mafic granulite.展开更多
基金the financial support from the National Natural Science Foundation of China(Nos.51572061,51621091,and 51321061)the Heilongjiang Touyan Team Program。
文摘The A_(2)B_(2)O_(7)-type rare earth zirconate compounds have been considered as promising candidates for thermal barrier coating(TBC) materials because of their low sintering rate,improved phase stability,and reduced thermal conductivity in contrast with the currently used yttria-partially stabilized zirconia (YSZ) in high operating temperature environments.This review summarizes the recent progress on rare earth zirconates for TBCs that insulate high-temperature gas from hot-section components in gas turbines.Based on the first principles,molecular dynamics,and new data-driven calculation approaches,doping and high-entropy strategies have now been adopted in advanced TBC materials design.In this paper,the solid-state heat transfer mechanism of TBCs is explained from two aspects,including heat conduction over the full operating temperature range and thermal radiation at medium and high temperature.This paper also provides new insights into design considerations of adaptive TBC materials,and the challenges and potential breakthroughs are further highlighted for extreme environmental applications.Strategies for improving thermophysical performance are proposed in two approaches:defect engineering and material compositing.
基金Sponsored by the National Natural Science Foundation of China (50801005)
文摘Based on defect chemistry theory and molecular dynamics,the defect formation energy and its relationship with the mechanism of pyrochlore-fluorite phase change were investigated,so as to reveal the underlying mechanism of high-temperature stability of pyrochlore zirconates.Results showed that with the rise of the atom mass of A,the defect formation energies decreased that meant the crystal structure tended to become more disordered.Noticeably,the first nearest cation antisite dominated the pyrochlore disorder transformation process.In addition,it was found that the diffusion of oxygen atoms was far higher than that of cations,and was increased with the temperature,thus also promoting the pyrochlore-fluorite transformation process.
基金This work is supported by the National Natural Science Foundation of China(Nos.51865044,52062040)Science and Technology Projects of Inner Mongolia Autonomous Region(Nos.2021PT0008,2022ZD02,2022MS05003)Basic Scientific Research Expenses Program of Universities Directly under Inner Mongolia Autonomous Region(Nos.JY20220041,JY20220062).
文摘Developing new high-entropy rare-earth zirconate(HE-RE_(2)Zr_(2)O_(7))ceramics with low thermal conductivity is essential for thermal barrier coating materials.In this work,the average atomic spacings,interatomic forces,and average atomic masses of 16 rare-earth elements occupying the A site of the cubic A_(2)B_(2)O_(7) crystal structure were calculated by density functional theory.These three physical qualities,as vectors,characterize the corresponding rare-earth elements.The distance between two vectors quantitatively describes the difference between two rare-earth elements.For greater differences between two rare-earth elements,the disorder degree of HE-RE_(2)Zr_(2)O_(7)is greater,and therefore,the thermal conductivity is lower.According to the theoretical calculations,the thermal conductivity of the ceramics gradually increases in the order of(SC_(0.2)Y_(0.2)La_(0.2)Ho_(0.2)Yb_(0.2))_(2)Zr_(2)0_(7),(SC_(0.2)Ce_(0.2)Nd_(0.2)Eu_(0.2)Gd_(0.2))_(2)Zr_(2)0_(7),(SC_(0.2)Y_(0.2)Tm_(0.2)Yb_(0.2)Lu_(0.2))_(2)Zr_(2)0_(7),and(Sc_(0.2)Er_(0.2)Tm_(0.2)Yb_(0.2)Lu_(0.2))_(2)Zr_(2)O_(7).Using the solution precursor plasma spray method and pressureless sintering method,four types of HE-RE2Zr2Oz powder and bulk samples were prepared.The samples all showed a single defective fluorite structure with a uniform distribution of the elements and a stable phase structure.The thermal conductivities of the sintered HE-RE_(2)Zr_(2)0_(7) bulk samples ranged from 1.30 to 1.45 Wm^(-1).K^(-1) at 1400℃,and their differences were consistent with the theoretical calculation results.Among the ceramics,(Sc_(0.2)Y_(0.2)La_(0.2)Ho_(0.2)Yb_(0.2))_(2)Zr_(2)O_(7) had the lowest thermal conductivity(1.30 W·m^(-1)·K^(-1),1400℃),highest thermal expansion coefficient(10.19×10^(-6) K^(-1),200-1400℃),highest fracture toughness(1.69±0.28 MPa·m^(1/2)),and smallest brttleness index(3.03μm^(1/2)).Therefore,(Sc_(0.2)Y_(0.2)La_(0.2)Ho_(0.2)Yb_(0.2))_(2)Zr_(2)0_(7)is considered to be an ideal candidate material for next-generation thermal barrier coating applications.
基金support from the National Key Research and Development Program of China(No.2021YFA0715801)the National Natural Science Foundation of China(No.51972116 and 52122204)+1 种基金the,Guangzhou Basic and Applied Basic Research Foundation(No.202201010632)the China Postdoctoral Science Foundation(2021M691051).
文摘Ultrafine-grained(Sm_(0.2)Gd_(0.2)Dy_(0.2)Er_(0.2)Yb_(0.2))_(2)Zr_(2)O_(7)high-entropy zirconates with single fluorite structure have been fabricated by high-pressure sintering of the self-synthesized nanopowders for the first time.The as-sintered samples exhibit a good microstructure with a grain size of 220 nm and a relative density of 96.8%,which yield excellent comprehensive mechanical properties with a high Vickers hardness of 12.5 GPa and a high fracture toughness of 3.4 MPa·m1/2.In addition,the as-sintered samples possess a good thermostability with the grain growth rate of 30 nm/h,and a low thermal conductivity of 1.57 W·m^(-1)·℃^(-1)at room temperature.The superior mechanical and thermal properties are primarily attributed to the“high-entropy”and grain-refinement effects and good interface bonding.
基金financially supported by the Provincial Natural Science Foundation of Hunan(Nos.2019JJ50831,2023JJ30505 and 2023JJ40541)the China Postdoctoral Science Foundation(Nos.2017M622597 and 2021M690591)+2 种基金the Open Research Fund Program of Fundamental Science on Radioactive Geology and Exploration Technology Laboratory(East China University of Technology)(No.2022RGET04)the National Foreign Expert Project(No.G2022029012L)the National Nature Science Foundation of China(No.41002022)。
文摘The Jiuyishan granitic complex,located in the Nanling Range,South China,is composed of five granitic plutons(Xuehuading,Jinjiling,Pangxiemu,Shaziling and Xishan).Zircon U-Pb dating of four plutons(Jinjiling,Pangxiemu,Shaziling and Xishan)yielded similar ages of approximately 153 Ma,indicating indistinguishable ages within error.Three plutons except the Shaziling pluton,have consistentε_(Nd)(t)(-7.8 to-5.8)andε_(Hf)(t)(-9.1 to-2.2)values,which are similar to those of the lower crustal granulitic metasedimentary and meta-igneous rocks in South China.Compared to other three plutons,the Shaziling pluton has consistentε_(Nd)(t)(-7.4 to-6.8)andε_(Hf)(t)(-7.5 to-4.7)values and shows similar source,but the Shaziling mafic microgranular enclaves(MMEs)show variableε_(Hf)(t)(-14.2 to 4.8)values,indicating a remarkable mantle magma injection of the Shaziling pluton.Zircon Ce/Sm-Yb/Gd,whole-rock CaO-P_(2)O_(5)and CaO-TiO_(2)linear trends reveal that from the Xishan to the Shaziling and from the Jinjiling to the Pangxiemu granites,they experienced apatite and titanite fractionation,respectively.Zircon Th,U,Nb,Ta,Hf,Ti,Y,P and rare earth element(REE)contents and whole-rock Sr,Ba and Rb contents also show that the Shaziling,Xishan,Jinjiling and Pangxiemu granites followed a discontinuous evolutionary series,but the Pangxiemu granites exhibit highly evolved nature.Four main controlling factors of W-Sn and rare metal mineralization in granitic rocks were discussed,and we found that the mineralization in Jiuyishan granitic complex was mainly controlled by the fractionation degree and crystallization temperature,but were rarely affected by oxygen fugacity and mantle material input.The Pangxiemu granites show particularly higher Rb and Ta contents than the other three plutons,implying that the ore deposits developed in the Jiuyishan Complex were directly related to the most evolved Pangxiemu pluton,with the occurrence of Rb and Ta as the most likely rare metal mineralization in the Jiuyishan District.A crystal mush model is proposed to interpret the petrogenetic and mineralizing processes of the Jiuyishan granitic complex.
基金This study was jointly supported by the Science&Technology Fundamental Resources Investigation Program(2022FY101800)National Science Foundation(92162212)+1 种基金the project from the Key Laboratory of Tectonics and Petroleum Resources(China University of Geosciences,Wuhan)(TPR-2022-22)the International Geoscience Programme(IGCP-675)。
文摘The Ordos Basin(OB)in the western part of the North China Craton(NCC),was located at the jointed area of multi-plates and has recorded the Mesozoic tectonic characteristics.Its tectonic evolution in the Mesozoic is significant to understand the tectonic transformation of the northern margin of the NCC.In this work,the detrital zircon and apatite(U-Th)/He chronological system were analyzed in the northern part of the OB,and have provided new evidence for the regional tectonic evolution.The(U-Th)/He chronological data states the weighted ages of 240‒235 Ma,141 Ma with the peak distribution of 244 Ma,219 Ma,173 Ma,147‒132 Ma.The thermal evolution,geochronological data,and regional unconformities have proved four stages of regional tectonic evolution for the OB and its surroundings in the Mesozoic:(1)The Late Permian-Early Triassic;(2)the Late Triassic-Early Jurassic;(3)the Late Jurassic-Early Cretaceous;(4)the Late Cretaceous-Early Paleogene.It is indicated that the multi-directional convergence from the surrounding tectonic units has controlled the Mesozoic tectonic evolution of the OB.Four-stage tectonic evolution reflected the activation or end of different plate movements and provided new time constraints for the regional tectonic evolution of the NCC in the Mesozoic.
基金supported by the French Agence Nationale de la Recherche(19-CE31-0002 AstroMeso)the European Research Council under the European Union’s Horizon 2020 Research and Innovation Program(Advanced Grant AstroGeo-885250).
文摘When interpreting results,it is imperative to have some understanding of the degree to which the results are replicable.If the results cannot be replicated with independent data,then interpretations from the results become questionable.To minimize the potential for misinterpretations,the current study analyzes six time-series derived from globally sampled U-Pb zircon databases–of which,two are independent igneous databases,one being a quasi-independent igneous database,and three being independent detrital databases.These time-series are then analyzed with standard statistical methods to evaluate replicability.The methods include bandpass filtering to transform the raw time-series into stationary sequences,Student’s t-test,Monte Carlo simulations,periodograms from spectral analysis,correlation studies,and correlograms.Each test is designed to determine the replicability of a specific time-series,as well as the replicability of periodicities found from the time-series.The results show at least three key components to assessing replicability:(a)U-Pb igneous and detrital zircon age distributions are highly replicable,(b)time-series replicability gradually deteriorates with age,and(c)replicability is scale dependent,with low frequency cycles being more replicable than high frequency cycles.From the tests,we conclude that four harmonic cycles are highly replicable and statistically significant,these being periodicities of 810,270,90,and 67.5-myr.
基金supported by the National Natural Science Foundation of China(41925011)the National Key R&D Program of China(2022YFC2903601).
文摘The Tongshan porphyry Cu deposit is well known as one of the most economically significant porphyry deposits in northeast China.Recently,Tongshan has become the largest porphyry Cu deposit in northeast China with the successful exploration of the concealed ore zone V.Ore zone V has the largest Cu tonnage(562 Mt@0.50% Cu)and extends into the eastern segment at Tongshan.Compared with ore zones I-III,which are hosted within granitic rocks in the western segment,the ore zone V mainly occurs in Duobaoshan volcanic rocks and the roof pendants of newly discovered intrusions.Here,we conducted a study of the understudied eastern ore zone and found that copper mineralization is associated with the newly discovered suites in the eastern segment at Tongshan.Two periods of ore-bearing quartz veins with different widths have been recognized,including quartz-chalcopyrite-pyrite veinlets(0.1-0.2 cm)and quartz-chalcopyrite-polymetallic sulfide wide veins(>0.5 cm).The latter veins can be divided into four stages(I-IV)of mineralization and alteration,which are closely related to the newly discovered granodiorite and dacite porphyry.Our new zircon U-Pb ages show that the granodiorite and dacite porphyry were developed between 228-223 Ma,suggesting that the overprinting porphyry copper mineralization occurred in the Triassic.The Triassic suites have adakite-like character with high Sr/Y,and show no or minimal negative Eu anomalies,indicating early dominant amphibole with limited plagioclase fractionation.For the Triassic intrusions,the high zircon Eu/Eu*(0.67-0.89),Δ_(FMQ)(1.04±0.53;whereΔ_(FMQ)is the log fO_(2)difference between the sample value and the fayalite-magnetite-quartz mineral buffer),hygrometer values(∼7.19 wt.% H_(2)O)and high whole-rock Fe_(2)O_(3)/FeO,Sr/Y,V/Sc and 10,000×(Eu/Eu*)/Y ratios together indicate the Triassic magmas were oxidized and hydrous.These contents and ratios of the Triassic suites are significantly higher than those of the Ordovician suites(Δ_(FMQ)=0.74±0.26,∼5.90 wt.%H_(2)O),suggesting that the newly discovered Triassic magmas are more oxidized and hydrous,with high potential for porphyry copper mineralization.Based on the investigation of mineralization and the above results,we proposed that multiple superimposed mineralizations can help form a large-scale deposit and the southeastern segment is a favorable exploration area at Tongshan.
基金supported by the National Key Research and Development Program(Nos.2022YFB3404501 and 2022YFB3404500)National Natural Science Foundation of China(Nos.52025041,U2341267,52374360,52174294,52450003,52472031,12305374 and 52104305).
文摘TiAl alloys were melted in BaZrO_(3)crucibles without and with Y addition at 1550℃for 5,10,and 15 min,respectively.The effect of the melting time and Y addition on the interaction between the crucibles and the alloys was investigated.Results revealed that the interaction extent was intensified with the increasing melting time.However,it could be effectively suppressed by adding Y into the alloy due to the in situ generated Y_(2)O_(3)protection layer.The thickness of the interaction layer could be decreased from 95.6 to 25.1μm with Y addition at 1550°C for 15 min.In addition,a significant deoxidation effect was achieved by adding Y,and the O concentration of the alloy was decreased from 0.2 to 0.0561 wt.%.In comparison with Al_(2)O_(3),MgO,CaO,and Y_(2)O_(3)crucibles,BaZrO_(3)crucible combined with Y addition exhibited the lowest O contamination to the alloy melt.
基金financed by the Inner Mongolia Geological Exploration Fund Project (Grant No. 2020YS03)the project of “Geology of Mineral Resources in China” from China Geological Survey (Grant Nos. DD20221695, DD20190379, DD20160346)+1 种基金the Project of Transformation in Scientific and Technological Achievements (Grant Nos. 2023CX10, HE2121)the Fundamental Research Funds of the Central Public Welfare Scientific Research Institutes (Grant No. JKYZD202313)
文摘The Shuangjianzishan deposit is a typical magmatic-hydrothermal deposit located in the southern Great Xing'an Range.Recent investigations have identified significant copper and tin mineralization at depth within the Shuangjianzishan deposit;however,the coupling relationship between magmatic emplacement and mineralization processes remains debated.This study presents whole-rock geochemistry,zircon LA-ICP-MS U-Pb dating,and zircon Hf isotope analyses of granite from the northern Shuangjianzishan deposit.The analysis results indicate the granite crystallized between 252.3 and 257.9 Ma,corresponding to Late Permian magmatic activity.The granite displaysε_(Hf)(t)=5.95-14.87,and t_(DM2)=333-900 Ma.Geochemically,the granite is rich in Si and Al,with high K,classified as a calc-alkaline,weakly peraluminous rock.LREEs are enriched,while HREEs are depleted,and a slight negative Eu anomaly,all of which are consistent with A-type granite characteristics.The Hercynian granite in the Shuangjianzishan deposit formed during the latter or post-collisional stages of the collision orogeny following the closure of the Paleo-Asian Ocean in the late Paleozoic era.The material source indicates a mixed origin,involving both crust and mantle contributions.The granite is also enriched in Cu,Pb,and Zn,suggesting its potential role as an ore-forming material source for the Shuangjianzishan deposit.This study proposes a potential link between Hercynian magmatism and mineralization at the Shuangjianzishan deposit for the first time,suggesting that multistage metallogenesis may be a response to successive magmatic events from Hercynian to Yanshanian periods in the mining area.
基金financially supported by the Yunnan Fundamental Research Projects(No.202201AT070077)the Ministry-Province Cooperation Pilot Projects(No.2023ZRBSHZ059)+1 种基金the Major Science and Technology Special Plan of Yunnan Province(No.202202AG050006)the National Natural Science Foundation of China(No.41603032)。
文摘Lower Carboniferous clastic sedimentary rocks(i.e.,the Nanduan Formation)in the Changning-Menglian belt of the southeastern Tibetan Plateau may provide new insights into the tectonic evolution of the Paleo-Tethys Ocean.This paper presents new petrographic,geochemical,and detrital zircon U-Pb age data to constrain the provenance and depositional setting of these rocks.Sandstone samples of the Nanduan Formation are all quartz arenites(Q_(92-99)F_(1-7)L_(0-2))with high SiO_(2)contents(85.1 wt.%-95.2 wt.%;average=90.9 wt.%),indicating high compositional maturity.They exhibit fractionated rare earth element(REE)patterns,with light REE enrichment[(La/Yb)_(N)=6.48-12.1]and negative Eu anomalies(Eu/Eu^(*)=0.53-0.74),and marked negative Sr-Cs-V-Cr-Ni anomalies in upper continental crust-normalised multi-element diagrams.The geochemical features and heavy mineral assemblages suggest that sediments were mainly derived from ancient sedimentary rocks in cratonic interiors or stable continental areas,and were probably deposited in a passive continental margin setting.Detrital zircon U-Pb dating(n=256)of the Nanduan Formation sandstones defines three distinct age peaks in the Pan-African(600-500 Ma),younger Grenvillian(950-850 Ma),and older Grenvillian(1250-1000 Ma).Their zircon age spectra are similar to those of Lower Paleozoic sedimentary rocks(i.e.,the Mengtong and Mengdingjie groups)in the BaoshanSibumasu Block,but significantly different from those of older rocks in the Simao-Indochina and other surrounding blocks(i.e.,the western Yangtze,western Cathaysia,western Qiangtang,Tethyan Himalaya,and Lhasa blocks).This suggests that the Nanduan Formation was deposited at the margin of the Baoshan-Sibumasu Block.Combining the new data presented in this study with published data,we suggest that the Nanduan Formation and underlying Lancang Group were deposited in the same setting during the Early and Late Paleozoic,respectively.
基金supported by the Geological Survey of China(No.DD20221645)the National Natural Science Foundation of China(Nos.42171010,42072141,41702118)。
文摘The Cenozoic source-to-sink history of the Qaidam Basin is crucial for understanding of the basin-filling architecture,mountain-building processes and even the dynamics of the Tibetan Plateau growth.However,the provenance history of Cenozoic strata in the Qaidam Basin remains ambiguous,especially in the northern Qaidam Basin.This controversy highlights the importance of obtaining the spatial source-to-sink relationships between the Qaidam Basin and its surrounding mountain ranges.In this study,we investigated the detrital zircon U-Pb ages of modern fluvial systems draining the East Kunlun Mountain.Their detrital zircon age distributions fall into five age groups:300-190,530-360,1000-560,2000-1100 and 2650-2000 Ma.The dominant age groups are 530-360 and 300-190 Ma,which represent the successive subduction of the Proto-Tethys and PaleoTethys Oceans and the subsequent continental collisions,respectively.Combining these new detrital zircon U-Pb ages with available age datasets,we finally obtained complete detrital zircon age information for modern fluvial systems in the whole Qaidam Basin.The U-Pb age distributions of modern river sands reveal that the zircon age signature of basement rocks in the East Kunlun Mountain is significantly different from that in the South Qilian Mountain but is similar to that in the Altyn Tagh Mountain.Moreover,these zircon age observations were confirmed by the significant difference in the Nd isotopic signature of modern river sands,which reveals a significant difference between the East Kunlun Mountain and South Qilian Mountain in the formation and evolution process.
基金funded by the National Science Centre(NCN,Poland)project nos.2018/29/B/ST10/02315 and 2019/33/B/ST10/01728 and the Swedish Research Council(Vetenskapsrådet)grant no.2019-03688.OL is grateful to the Deutsche Forschunggemeinschaft for the support of his COSC-2 research(DFG 867/12-1,13-1,and 13-2)supported by a National Science Foundation(USA)grant EAR2050246.
文摘Detrital zircon geochronology is reported from the c.1200 m thick Cambro-Ordovician sedimentary succession recovered in core from the COSC-2 continental drilling project in the Scandinavian Caledonides.Above a regolith marking the sub-Cambrian peneplain,a lower to middle Cambrian(?)succession comprises conglomerate,sandstone and shale overlain by gravity flows fining upwards into the Alum Shale Formation.First results of detrital zircon geochronology from the Cambrian(?)succession show that the basal section of the autochthonous cover is characterized by mainly late Paleoproterozoic–early Mesoproterozoic detrital grains.The middle part of the succession is dominated by late Paleoproterozoic detritus with minor Mesoproterozoic and Archean input.The upper part of lower Cambrian(?)succession is characterized by Archean to Cambrian detritus.The maximum depositional age is calculated to 530.5±4 Ma for the upper part of the lower Cambrian succession.Two samples from the Lower Ordovician(?)succession above the Alum Shale Formation show predominantly Mesoproterozoic to early Neoproterozoic(1.5–0.9 Ga)ages.The autochthonous lower Cambrian(?)passive margin succession in the lower section is dominated by local detritus,sourced exclusively from the Eastern Segment of the Sveconorwegian Orogen,which includes the basement studied in COSC-2.Up-section,the provenance shifts towards the Transscandinavian Igneous Belt and Svecofennian Orogen sources,with the youngest part of the succession showing a notable input of Neoproterozoic–Cambrian active margin detritus.The Ordovician(?)succession is characterized by populations,likely derived from the Sveconorwegian Orogen,and a minor cratonic contribution.Statistical analysis of detrital zircon datasets across Baltica suggests that the Southern Baltica/Sandomirian Arc,rather than the Timanian Orogen,was a significant source of detrital material across the paleocontinent.The influence of Timanian Orogen grains is limited to northernmost Scandinavia,whereas Sandomirian detritus reached central Scandinavia in the lower to middle Cambrian and remained prevalent in southern Scandinavia into the Lower Ordovician.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.42172258,42072227,U2244205)the Science and Technology Major Project of Xinjiang Uygur Autonomous Region,China(2023A03002)+2 种基金the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(Grant No.2015BAB05B04)the Joint Innovation Fund of China National Uranium Co.,Ltd.,and State Key Laboratory of Nuclear Resources and Environment(Grant No.NRE2021-01)the China Geological Survey(Grant Nos.DD20242868,DZLXJK202206)。
文摘The Southwest Tianshan is the suture zone between the Central Tianshan and the Tarim Craton.To better illustrate the subduction polarity of the Southwest Tianshan Ocean,a systematic detrital zircon LA-ICP-MS U-Pb geochronology of sedimentary rocks of the Devonian Apadaerkang Formation and the Carboniferous Akeqiayi Group of the Biedieli area in the Wushi region is the focus.Detrital zircon ages indicate that the youngest grains of the targeted quartz sandstones are Late Devonian and Early Carboniferous in age,respectively.These ages also have relatively similar age spectra,indicating a similar tectonic setting and source in the Biedieli area during the Devonian to Carboniferous.The main spectrum peaks occur at 2360,1960,810,640 and 440 Ma,with a principal age peak in the early Paleozoic(474-430 Ma),and the Central Tianshan Terrane is indicated as the main source.The detrital zircon geochronology and sedimentary characteristics of the Biedieli rocks indicate that the Paleozoic sedimentary rocks in the northern Wushi region were formed at an active continental margin,associated mainly with the early Paleozoic subduction of the South Tianshan Ocean.
基金jointly supported by the Scientific Research Foundation of Third Institute of Oceanography,Ministry of Natural Resources,Xiamen(No.2018002)the Guangxi Natural Science Fundation(No.2022GXNSFBA035588)+1 种基金the National Natural Science Foundation of China(Nos.41506050,41402193)the Scientific Research Foundation of Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration(No.19-185-17-09)。
文摘The tectonic evolution of Borneo and the affiliation between Southern and Northern Borneo remains unclear.The Rajang and Crocker Fan sediments,as one of the largest ancient submarine fans in Southeast Asia have witnessed the tectonic evolution of Borneo since at least the late Mesozoic.In this study,we present laser ablation inductively coupled plasma mass spectrometer(LA-ICP-MS)U-Pb dating and Hf isotopic results of detrital zircons from the Trusmadi and Crocker formations within the Crocker Fan of Sabah,Northern Borneo.Our results,coupled with previous data,show that the Crocker Fan sediments in Sabah of Northern Borneo display similar age spectra to the Rajang Fan sediments in Sarawak of Central Borneo,with two major age clusters at 130-80 and 280-200 Ma.Further provenance analysis based on mineral shape with a prismatic characteristic and similar detrital zircon Hf isotopes of the two formations illustrates that the Jurassic-Cretaceous and partly Triassic detrital zircons of the Crocker and Rajang Fan sediments were derived from the erosion of contemporaneous magmatic rocks;part of Permian-Triassic ones could be the recycling of the Jurassic deposits in SW Borneo.The initial provenance of these Permian-Triassic detritus could be synchronous magmatic rocks in the Tin belt of the Malay Peninsula.Combining with previous data,we propose that the entire Borneo continent,including both Southern and Northern Borneo,developed a common Mesozoic continental magmatic arc.Moreover,we postulate that the Rajang and Crocker fans formed in a fore-arc extensional rift basin related to the retreat of the subducted Paleo-Pacific Plate beneath the Northern Borneo margin.
基金financially supported by the National Natural Science Foundation of China(Grant No.41902224,41602209).
文摘Detrital zircon and apatite U-Pb-Hf isotope and trace element analyses of the late Mesoproterozoic to early Neoproterozoic strata in southern Jilin provide detailed information on the sediment provenance and tectonic setting of the northeastern margin of the North China Craton(NCC).Here,we present U-Pb and Lu-Hf analyses of 712 detrital zircons,and U-Pb analyses of 347 detrital apatites from the Baifangzi,Diaoyutai and Qiaotou formations.The Baifangzi and Diaoyutai formations are dominated by Neoarchean(2.5-2.6 Ga)and Paleoproterozoic(1.8-1.9 Ga)zircons,indicating a predominant NCC provenance.The Qiaotou Formation is dominated by Mesoproterozoic(1.5-1.7 Ga and 1.1-1.3 Ga)zircons with mainly positiveεHf(t)values,which are similar to those from eastern Laurentia,implying a significant provenance transition.The detrital apatite age spectra of the Baifangzi and Diaoyutai Formations show major populations at 1.8-1.9 Ga and 1.1-1.3 Ga.Based on their trace element compositions,the Mesoproterozoic apatites were mainly sourced from metamorphic rocks,indicating regional metamorphism occurred in the NCC during 1.1-1.3 Ga.Combining these data with regional studies,we propose that the NCC was adjacent to eastern Laurentia during the assembly of the Rodinia supercontinent.
基金supported by the National Natural Science Foundation of China(Nos.42172035 and 41572024)the Fundamental Research Funds for the Liaoning Universities(No.LJ202410166012)+1 种基金Geological Survey Project of China(No.DD20221645)Open Foundation(No.203124)of State Key Laboratory of Palaeobiology and Stratigraphy(Nanjing Institute of Geology and Palaeontology,CAS)。
文摘The Ediacaran Period records a significant turning point in the evolution of life on Earth,witnessing the rise to ecological dominance of macroscopic tissue-grade organisms.The Wenghui biota from the Doushantuo Formation of South China hosts abundant multicellular algal macrofossils and problematica,some of which might be closely related to taxa from classic Late Ediacaran assemblages from South Australia and the White Sea biota of Russia.However,a lack of well-resolved isotopic age estimates has hampered efforts to constrain the timing of appearance of the Wenghui biota,obfuscating its significance to our understanding of Ediacaran macroevolution in the aftermath of the Snowball Earth events.Here,we present the first SHRIMP zircon U-Pb dating results for samples obtained from a laminated tuff ash layer at the base of the Wenghui biota in the Doushantuo Formation,Jiangkou County,Tongren City,Guizhou Province,China.Our analyses yield an age of 595.4±5.3 Ma for the first appearance of Wenghui biota,suggesting that its appearance postdated that of the Lantian and Weng'an biotas,but preceded that of the Miaohe biota.These newly obtained age proxies offer an independent test of previous isotopic estimates for the age of the Wenghui biota,providing new chronostratigraphic evidence to map the succession of Ediacaran fossil assemblages on the Yangtze Platform during the Doushantuo interval.These data suggest that the Lantian,Weng'an,Wenghui,and Miaohe biotas may record a sequence of biotic assemblages attesting to successive phases in the radiation of Ediacaran macroscopic organisms,particularly macroalgae.
基金supported by The Special Funds for Natural Resource Development in Jiangsu Province(2200113-35)The Central Financial Geological Survey Project of the China Geological Survey(DD20230800702).
文摘The Ning-Wu Basin is an important part of the Middle-Lower Yangtze River Metallogenic Belt in eastern China.It contains well-preserved Mesozoic volcanic sequences that document significant geodynamic evolution.However,uncertainties surrounding the ages of eruptions and the temporal relationships between the four main volcanic cycles—the Longwangshan,Dawangshan,Gushan and Niangniangshan formations—have hindered our understanding of magmatic pulsation and its connection to iron mineralisation.Here,high-precision LA-ICP-MS zircon U-Pb dating of four fresh volcanic samples(one per formation)reveals weighted mean ages of 132.3±1.0 Ma(Longwangshan;MSWD=1.3),130.4±1.6 Ma(Dawangshan;MSWD=1.3),128.1±1.9 Ma(Gushan;MSWD=2.0)and 127.2±1.1 Ma(Niangniangshan;MSWD=0.23).These dates constrain volcanic activity to the Early Cretaceous Valanginian-Hauterivian interval and show a systematic trend of increasingly younger ages spanning~8 Ma(133-125 Ma).This magmatism can be subdivided into three phases:initiation(133-132 Ma),peak activity(132-130 Ma)and cessation(128-125 Ma).The episodic volcanism correlates with the accelerating rollback of the Pacific subduction zone,which drives crustal melting and asthenospheric upwelling.Notably,these cycles supplied the thermal energy,fluids and iron-rich melts that were essential for the formation of porphyritic iron deposits in the basin.By establishing a highresolution chronostratigraphic framework,this study sheds light on the spatiotemporal evolution of the Ning-Wu Basin,elucidating the coupling between crust-mantle dynamics,volcanic cyclicity and ore-forming processes across eastern China’s metallogenic belt.
基金financially supported by the National Major Science and Technology Project of China(No.2016ZX05004-004)the State Scholarship Grant from the China Scholarship Council(CSC)to Yinggang Zhang。
文摘The ocean crust remnants of the Proto-Tethys were preserved as the Kudi ophiolites in the West Kunlun Orogenic Belt(WKOB),and its evolutionary history was mainly constructed by research on igneous or metamorphic rocks in the WKOB.Sedimentary rocks in the WKOB received little attention in the past;however,they could provide important constraints on the evolution of the oceanic lithosphere.Here,a series of shales and greywackes found in the Kudi area of WKOB were studied to constrain their deposition ages and explore their significance in the evolution of the ProtoTethys oceanic crust.The U-Pb dating and europium anomaly(Eu/Eu^(*))were analyzed for detrital zircons from greywackes interlayers,while bulk rare earth elements and yttrium(REY)of the shales were measured.Detrital zircons U-Pb ages yield a maximum deposition age of 436 Ma for the greywackes and black shales,while the REY distribution patterns of the black shales are similar to those of the Tarim Ordovician Saergan shales.Accordingly,the studied WKOB black shales were deposited in the Proto-Tethys Ocean during the Late Ordovician-Early Silurian period.The maximum deposition age at 436 Ma may represent a minimum closure time of the Proto-Tethys Ocean,which is also supported by the absence of increases in Eu/Eu^(*)values during the Late Ordovician-Early Silurian.Besides,our Eu/Eu^(*)values in detrital zircons indicate diminished orogenesis during the Archean to Meso-Proterozoic,subduction-related accretion at the margins of the supercontinent Rodinia during the Neoproterozoic.
基金financially supported by the Basic Foundation of Tianjin University of Commercethe Fund from the Key Laboratory of Continental Dynamics of Ministry of Natural Resources(J2306)。
文摘Deciphering high-pressure granulite-facies metamorphism and anatexis within a collisional orogeny can provide crucial constraints on geodynamic evolution and melt activity during subduction and exhumation.Combining petrographic observations,mineral chemistry,REE in Grt-Cpx thermobarometry,and previous work,at least four stages are suggested for the metamorphic evolution of the mafic granulites in the South Altun,including the protolith stage,the high-pressure granulite-facies stage(909-1037℃and 17.3-30 kbar),medium-pressure granulite-facies overprint(9.1-11.9 kbar and 753-816℃),and subsequent late amphibolite-greenschist-facies metamorphism.Zircon U-Pb dating shows that the mafic granulites underwent high-pressure granulite-facies metamorphism at 497.2±3.7 Ma,while the leucosome formed at 498.2±2.9 Ma.Thus,the leucosomes from the host mafic granulite may have been formed at the high-pressure granulite-facies metamorphic event.The characteristics of zircon morphology,mineral inclusions,low Th/U values,HREE enrichment,and negative Eu anomalies indicate that these zircons from the leucosome were formed from the metamorphic melts.The characteristics of whole-rock major and trace elements as well as Hf isotopic features of zircons between the leucosomes and the host mafic granulite indicate that the melt may have been generated by the partial melting of the host mafic granulite.
