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Carbon isotopes of asphaltene-occluded hydrocarbons:A proxy for bitumen vein source identification in northwest Sichuan Basin,China 认领 引用
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作者 Peng Fang Jia Wu +6 位作者 Xue-Min Xu Bin Shen Wei-Lin Sun Xiao Jin Feng Chen Ning-Ning Zhong Ming-Hui Zhou 《Petroleum Science》 SCIE EI CAS CSCD 2026年第4期1636-1649,共14页
The Lower Cambrian bitumen veins in northwestern Sichuan Basin originated from Precambrian paleooil reservoirs,yet the severe alterations of bitumen and high maturity of potential source rocks challenge conventional o... The Lower Cambrian bitumen veins in northwestern Sichuan Basin originated from Precambrian paleooil reservoirs,yet the severe alterations of bitumen and high maturity of potential source rocks challenge conventional oil-source correlation.In this study,we focus on analyzing the stability of carbon isotopic compositions in asphaltene-occluded hydrocarbons to reveal their preservation of original organic signatures.Asphaltenes from the solid bitumen were investigated through gold tube closedsystem thermal simulation experiments(300–400℃).Free saturated hydrocarbons in raw samples exhibit 13C-enrichment(δ13C=-31.3‰)due to biodegradation,while thermal simulation experiments reveal progressive 13C-depletion of free saturated hydrocarbons(Δδ13C=-4.7‰)caused by kinetic isotope effects during thermal cracking.In contrast,asphaltene-occluded saturated hydrocarbons maintain exceptionalδ13C stability(-28.5‰±0.2‰)across the same stages,demonstrating complete protection by macromolecular shielding,and adsorbed hydrocarbons display intermediate behavior with moderateδ13C shifts,indicating partial shielding at asphaltene surfaces.Biomarker distributions(C27-dominant steranes,n-alkane bimodality,and n-alk-(1)-enes)in occluded hydrocarbons probably preserve original signatures unaffected by secondary alterations.The combinedδ13C signature(within the-26‰to-31‰range characteristic of shallow-water Doushantuo Formation)and biomarker evidence(consistent with Precambrian eukaryotic algal contribution)in occluded hydrocarbons conclusively identify the Ediacaran Doushantuo Formation as the bitumen source.These results demonstrate that asphaltene nanoaggregates effectively shield occluded components from secondary alterations and thermal maturation to a certain extent,providing reliable proxies for Precambrian oil-source correlation in altered reservoirs. 展开更多
关键词 Bitumen veins Asphaltenes Adsorbed/occluded hydrocarbons Carbon isotopes Organic matter source Sichuan Basin
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Searching for new neutron-rich isotopes in the rare-earth region at HIAF 认领 引用
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作者 Xiao‑Hui Sun He Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第8期252-260,共9页
The present study evaluates the production of new neutron-rich isotopes in the rare-earth region(Z=61-71)using projectile fragmentation of primary beams at 800 MeVucleon at the HIgh-rigidity Radioactive Ion Beam Line(... The present study evaluates the production of new neutron-rich isotopes in the rare-earth region(Z=61-71)using projectile fragmentation of primary beams at 800 MeVucleon at the HIgh-rigidity Radioactive Ion Beam Line(HIRIBL)of the High-Intensity heavy-ion Accelerator Facility(HIAF).The production potential of various projectiles was evaluated through measured and calculated production cross sections,revealing that198Pt may offer a clear advantage for accessing this region.With an optimized target thickness,fragmentation of198Pt could lead to the discovery of about 30 new isotopes in the rare-earth region at HIAF,thereby providing a strong opportunity for studies in both nuclear physics and nuclear astrophysics at HIAF. 展开更多
关键词 New neutron-rich isotopes Rare-earth region Fragmentation reaction HIAF
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Nitrogen and oxygen isotopes in nitrate and nitrite in the polluted surface waters from the Arno River Basin(Central Italy) 认领 引用 被引量：1
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作者 Lorenzo Chemeri Barbara Nisi +5 位作者 Andrea Pierozzi Jacopo Cabassi Marco Taussi Stefania Venturi Antonio Delgado Huertas Orlando Vaselli 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2026年第1期250-262,共13页
The Arno River Basin(Central Italy)is affected by a considerable anthropogenic pressure due to the presence of large cities and widespread industrial and agricultural practices.In this work,26 water samples from the A... The Arno River Basin(Central Italy)is affected by a considerable anthropogenic pressure due to the presence of large cities and widespread industrial and agricultural practices.In this work,26 water samples from the Arno River and its main tributaries were analyzed to assess the water pollution status.The geochemical composition of the Arno River changes from the source(dominated by a Ca-HCO3 facies)to the mouth(where a Na-Cl(SO4)chemistry prevails)with an increasing quality deterioration,as suggested by the Chemical Water Quality Index,due to anthropogenic contributions and seawater intrusion before flowing into the Ligurian Sea.The Ombrone and Usciana tributaries introduce anthropogenic pollutants into the Arno River,whilst Elsa tributary supplies significant contents of geogenic sulfate.The concentrations of dissolved nitrate and nitrite(up to 63 and 9 mg/L,respectively)and the respective isotopic values of?15N and?18O were also determined to understand origin and fate of the N-species in the Arno River Basin surface waters.The combined application of?15N-NO3 and?18O-NO3 and N-source apportionment modelling allowed the identification of soil organic nitrogen and sewage and domestic wastes as primary sources for dissolved NO3-.The?15N-NO2 and?18O-NO2 values suggest that the nitrification process affects the ARB waters,thus controlling the abundances and proportion of the N-species.Our work indicates that additional efforts are needed to improve management strategies to reduce the release of nitrogenated species to the surface waters of the Arno River Basin,since little progress has been made from the early 2000s. 展开更多
关键词 River geochemistry Water pollution Nitrogen stable isotopes Surface water management Water quality Anthropogenic pollution
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Production of 287,288Mc isotopes in the 48Ca+243Am reaction at China Accelerator Facility for Superheavy Elements 认领 引用 被引量：1
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作者 X.Y.Huang Z.Y.Zhang +38 位作者 J.G.Wang L.Ma C.L.Yang M.H.Huang X.L.Wu Z.G.Gan H.B.Yang M.M.Zhang Y.L.Tian Y.S.Wang J.Y.Wang Y.H.Qiang G.Xie S.Y.Xu Z.Zhao Z.C.Li L.C.Sun L.Zhu X.Zhang H.Zhou F.Guan Z.H.Li W.X.Huang Z.Qin Y.Wang X.J.Yin Y.F.Cui Z.W.Lu Y.He L.T.Sun Z.Z.Ren S.G.Zhou V.K.Utyonkov A.A.Voinov Yu.S.Tsyganov A.N.Polyakov D.I.Solovyev N.D.Kovrizhnykh M.V.Shumeiko 《Chinese Physics Letters》 SCIE EI CAS CSCD 2026年第1期9-16,共8页
We report the results of the experiment on synthesizing 287,288Mc isotopes (Z=115) using the fusionevaporation reaction 243Am(48Ca,4n,3n)287,288Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-... We report the results of the experiment on synthesizing 287,288Mc isotopes (Z=115) using the fusionevaporation reaction 243Am(48Ca,4n,3n)287,288Mc at the Spectrometer for Heavy Atoms and Nuclear Structure-2(SHANS2),a gas-filled recoil separator located at the China Accelerator Facility for Superheavy Elements(CAFE2).In total,20 decay chains are attributed to 288Mc and 1 decay chain is assigned to 287Mc.The measured oa-decay properties of 287,288Mc as well as its descendants are consistent with the known data.No additional decay chains originating from the 2n or 5n reaction channels were detected.The excitation function of the 243Am(48Ca,3n)288Mc reaction was measured at the cross-section level of picobarn,which indicates the promising capability for the study of heavy and superheavy nuclei at the facility. 展开更多
关键词 spectrometer heavy atoms fusionevaporation reaction China Accelerator Facility Superheavy Elements production decay chains isotopes ca am reaction mc
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Erratum:Production of 287,288Mc isotopes in the 48Ca+243Am reaction at China Accelerator Facility for Superheavy Elements[Chin.Phys.Lett.43 010101 (2026)] 认领 引用
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作者 X.Y.Huang Z.Y.Zhang +38 位作者 J.G.Wang L.Ma C.L.Yang M.H.Huang X.L.Wu Z.G.Gan H.B.Yang M.M.Zhang Y.L.Tian Y.S.Wang J.Y.Wang Y.H.Qiang G.Xie S.Y.Xu Z.Zhao Z.C.Li L.C.Sun L.Zhu X.Zhang H.Zhou F.Guan Z.H.Li W.X.Huang Z.Qin Y.Wang X.J.Yin Y.F.Cui Z.W.Lu Y.He L.T.Sun Z.Z.Ren S.G.Zhou V.K.Utyonkov A.A.Voinov Yu.S.Tsyganov A.N.Polyakov D.I.Solovyev N.D.Kovrizhnykh M.V.Shumeiko 《Chinese Physics Letters》 SCIE EI CAS CSCD 2026年第3期27-27,共1页
Fig.3.(a)α-particle energy spectra,and(b)decay-time distributions on a logarithmic scale for the observed 288Mc and its descendant nuclei.In the panel(a),the red histograms show the observed full-energy events,while ... Fig.3.(a)α-particle energy spectra,and(b)decay-time distributions on a logarithmic scale for the observed 288Mc and its descendant nuclei.In the panel(a),the red histograms show the observed full-energy events,while the corresponding blue histograms show the reconstructed events.The red smooth curves in panel(b)are the expected time distributions according to the corresponding half-lives extracted from this work. 展开更多
关键词 reconstructed eventsthe half lives production isotopes decay time distributions superheavy elements particle energy spectra
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Fe isotopes in sulfides in the Aguas Zarcas(CM2)chondrite:Implications for the history of the parent asteroids 认领 引用
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作者 Xinqian Zhu Xinyu Wang +7 位作者 Cheng Qian Kexin Deng Qi He Zaicong Wang Wen Zhang Ao Yang Fabin Pan Xiang Wu 《Acta Geochimica》 EI CAS CSCD 2026年第1期42-54,共13页
CM chondrites contain valuable insights into the formation and evolution of the solar nebula,as well as the secondary aqueous alteration processes that affected their parent bodies.Our study focuses on primary and sec... CM chondrites contain valuable insights into the formation and evolution of the solar nebula,as well as the secondary aqueous alteration processes that affected their parent bodies.Our study focuses on primary and secondary sulfides within the Aguas Zarcas(CM2)chondrite,investigating their formation mechanisms based on their morphology,textures,and compositions.Moreover,we infer the formation temperatures of the sulfides from 230 to 500℃ for primary and from 100 to 135℃ for secondary.We select representative grains and conduct Fe isotope measurements on them.The primary sulfides with δ56/54Fe ranging from -2.44‰ to +0.69‰are associated with sulfidesilicate melt segregation,while secondary sulfides with δ56/54Fe values between -1.83‰ and -0.14‰ are linked to aqueous alteration.Overall,the Ni content of the grains is positively correlated with δ56/54Fe.It might be related to the changes in crystal structure and chemical bond lengths due to the increase in nickel content.Fe isotopes provide a new perspective on sulfide formation and the evolution of a carbonaceous chondrite parent body. 展开更多
关键词 Aguas Zarcas Fe isotopes Chondrite Sulfide
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Investigation of the production of 152Tb and 155Tb terbium radioisotopes with europium targets 认领 引用
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作者 C.Yalçın 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第2期183-193,共11页
In recent years,terbium radioisotopes have been investigated for their potential therapeutic and diagnostic applications in nuclear medicine.This study aimed to investigate the production of 152 Tb and 155 Tb by... In recent years,terbium radioisotopes have been investigated for their potential therapeutic and diagnostic applications in nuclear medicine.This study aimed to investigate the production of 152 Tb and 155 Tb by alpha-induced reactions in detail,with a specific focus on determining the optimum production parameters and testing existing nuclear models.Given the limited number of experiments conducted on reactions related to terbium isotope production,it is necessary to perform theoretical calculations of cross sections over a wide energy range to gain a detailed understanding of terbium isotope production.To achieve this objective,the cross sections of the 151Eu(α,n)154 Tb reactions were calculated up to 60 MeV using the TALYS computer code with 432 different combinations of optical model parameters,level density,and strength function models.The theoretical reaction cross-section results were compared with the experimental results in the literature.The best input parameters were determined using the Threshold Logic Unit method,and these parameters were used in all isotope production calculations.Once the optimal model combination was determined,the total activity production and isotopic fraction of 152 Tb and 155 Tb isotopes were calculated in detail for beam energies of 17–50 MeV,different irradiation times,and varying 151 Eu and 153 Eu target thicknesses. 展开更多
关键词 Terbium radioisotopes Medical isotope production Alpha-induced reactions Cross section Threshold logic unit method
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Genesis of Late Carboniferous volcanic rocks in the Kebai Fault Zone,Western Junggar,Xinjiang:Constraints from zircon U-Pb age,whole rock geochemistry,and Sr-Nd-Pb isotopes 认领 引用
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作者 Wei Wang Chuan-Yi Tang +6 位作者 Zong-Quan Yao Yan Gao Feng-Bin Han Zong-Rui Xie Jian Chen Yuan-Feng Yang Ya-Fang Zhang 《Petroleum Science》 SCIE EI CAS CSCD 2026年第2期712-729,共18页
The Late Paleozoic tectonic evolution of the Junggar Basin played a critical role in the formation of its oil and gas resources;however,as most of the basin is covered by desert,the evolutionary process remains contro... The Late Paleozoic tectonic evolution of the Junggar Basin played a critical role in the formation of its oil and gas resources;however,as most of the basin is covered by desert,the evolutionary process remains controversial.In this study,we present a comprehensive analysis of the rock associations,petrography,ages,and systematic elemental and isotopic compositions of Carboniferous volcanic rocks obtained from drilling holes along the western margin of the basin,aiming to better constrain the late Paleozoic tectonic evolution of this region.Two zircon samples,from tuff and andesite layers,yielded concordant ages of 316.8±1.7 and 321.7±1.8 Ma,respectively,indicating intense volcanic eruptions during the Late Carboniferous.The analyzed volcanic rocks exhibited sodic calc-alkaline affinities,with SiO2content ranging from 53.46 to 61.57 wt%,TiO2content from 0.75 to 1.20 wt%,and a significantly higher Na2O content than that of K2O.In terms of trace elements,they showed variable enrichment in light rare earth elements((La/Yb)N=2.72 to 7.89)and large ion lithophile elements such as Ba,Th,U,and Sr.Low Cr(0.67-65.72)and Ni(0.86-34.90)contents,together with significant negative Eu anomalies(δEu=0.17 to 0.35),suggest variable fractionation of the primitive magma prior to eruption.All these features,combined with prominent Nb-Ta depletions in PM-normalized incompatible element spider diagrams,unambiguously indicate their genetic relationship with a subduction environment.However,the volcanic rocks showed low initial(87Sr/86Sr)i values(0.7039-0.7057)and positiveεNd(t)values(7.5-8.0).Moreover,the combined(208Pb/204Pb)i ranged from 37.7295 to 37.7851,(207Pb/204Pb)i ranged from15.4935 to 15.5037,and(206Pb/204Pb)i ranged from 17.8910 to 17.9254,indicating that their primitive magma originated from an extremely depleted mantle source with crustal contamination.Integrating this study with regional geology,we propose that the volcanic rocks in the Kebai Fault Zone were most likely formed in a back-arc basin setting induced by ridge subduction. 展开更多
关键词 Western Junggar Kebai Fault Zone Volcanic rocks SHRIMP zircon U-Pb chronology Element/isotope geochemistry
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Monsoon vs.non‑monsoon precipitation isotopes in Southwest China:Contrasting roles of moisture sources,Tibetan hydroclimate,and local amount effects 认领 引用
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作者 ZHAO Pei TANG Jialiang 《Journal of Mountain Science》 SCIE CSCD 2026年第5期2199-2209,共11页
Natural stable isotopes in precipitation provide important information on water vapor sources and atmospheric convection processes,which play key roles in climate change,hydrological cycle,and paleoclimate reconstruct... Natural stable isotopes in precipitation provide important information on water vapor sources and atmospheric convection processes,which play key roles in climate change,hydrological cycle,and paleoclimate reconstruction.However,the controlling mechanisms of precipitation isotopes in subtropical regions remain insufficiently understood.This study aimed to clarify the dominant controls on precipitation isotope variability and their seasonal differences in a typical subtropical region of Southwest China.Monthly precipitation samples were continuously collected at the Yanting experimental station in Sichuan,Southwest China from 2012 to 2020.The oxygen isotope ratio(δ18O)and deuterium excess(d-excess)in precipitation were analyzed,and their relationships with precipitation amount,large-scale atmospheric circulation,and moisture source regions were examined using statistical analysis and a structural equation model.The results showed a significant negative relationship between anomaly precipitation amount and monthlyδ18O values,particularly during the monsoon season,indicating a pronounced precipitation amount effect.Structural equation modeling revealed that this effect was mainly driven by hydrometeorological conditions over the seas and Tibetan Plateau.Moisture from the Bay of Bengal was identified as a more influential source than the South China Sea,largely associated with the El Niño-Southern Oscillation,and its contribution has increased in recent years.In contrast,during the nonmonsoon season,precipitationδ18O variations showed no significant relationship with any local factor,suggesting a combined influence of teleconnections and local processes.These findings demonstrate that precipitation isotopes in Southwest China are governed by distinct seasonal mechanisms,underscoring the critical roles of large-scale atmospheric circulation,Tibetan Plateau hydroclimate,and moisture source dynamics in modulating isotope variability across subtropical monsoon regions. 展开更多
关键词 Stable isotope Vapor source Structural equation model Precipitation amount effect Subtropical region Monsoon season
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Response of precipitation isotopes and water vapor sources to regional climate change on the Gannan Plateau,China 认领 引用 被引量：2
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作者 CHEN Fenli KANG Nan +4 位作者 WANG Shengjie GAO Minyan ZHANG Qiuyan LI Huizhen YAO Yiwen 《Journal of Arid Land》 SCIE CSCD 2025年第4期440-456,共17页
Precipitation isotopes(δ18O and δ2H)are closely related to meteorological conditions for precipitation generation and the initial state of water vapor source areas,and are essential to the study of the regiona... Precipitation isotopes(δ18O and δ2H)are closely related to meteorological conditions for precipitation generation and the initial state of water vapor source areas,and are essential to the study of the regional hydrological cycle.The deuterium excess(d-excess)indicates deviation in isotope fractionation during evaporation and can trace water vapor sources.This study analyzed 443 precipitation samples collected from the Gannan Plateau,China in 2022 to assess precipitation isotope variations and their driving factors.Water vapor sources were evaluated using the Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT),Concentration Weighted Trajectory(CWT),and Potential Source Contribution Factor(PSCF)models.Results showed that precipitation isotope values showed significant spatial and temporal variations on the Gannan Plateau.Temporally,precipitation isotope values peaked in June(when evaporation dominated)and minimized in March(depletion effect of air masses in the westerly wind belt).Spatially,the isotope values showed a distribution pattern of"high in the east and low in the west",which was mainly regulated by the differences in altitude and local meteorological conditions.Compared with the global meteoric water line(GMWL)with equation of δ2H=8.00δ18O+10.00,the slope and intercept of local meteoric water line(LMWL)for precipitation on the Gannan Plateau were smaller(7.49 and 7.63,respectively),reflecting the existence of a stronger secondary evaporation effect under the clouds in the region.The sources of water vapor on the Gannan Plateau showed significant seasonality and spatial heterogeneity.Specifically,the westerly belt and monsoon were the main water vapor transport paths at each sampling point,with Central Asian continental water vapor dominating in spring(53.49%),Indian Ocean water vapor dominating in summer(52.53%),Atlantic Ocean water vapor dominating in autumn(46.74%),and Atlantic Ocean and Mediterranean Sea water vapor dominating in winter(42.30%and 33.68%,respectively).Changes in the intensity of convective activity and Outgoing Longwave Radiation(OLR)affected the enrichment of isotopic values,which exhibited the same change trends as δ18O.During the precipitation process,the δ18O value first decreased and then increased.During the initial and final stages of precipitation process,precipitation was mainly influenced by continental air masses,while during the middle stage,it was controlled by marine air masses.The systematic research on precipitation isotopes and water vapor sources is important for climate change research and extreme precipitation prediction on the Gannan Plateau and other similar areas. 展开更多
关键词 precipitation isotopes deuterium excess(d-excess) water vapor sources Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT) Concentration Weighted Trajectory(CWT) Potential Source Contribution Factor(PSCF) Gannan Plateau
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Dataset of neutron energy region values for the in-reactor production of medical isotopes 认领 引用 被引量：1
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作者 Qing-Quan Pan Guo Lv +1 位作者 Sheng-Dian Zou Xiao-Jing Liu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2025年第8期18-25,共8页
Medical isotopes are the foundation material for nuclear medicine and are primarily produced through in-reactor irradia-tion.Neutron spectrum regulation is the main technical approach for enhancing the production of m... Medical isotopes are the foundation material for nuclear medicine and are primarily produced through in-reactor irradia-tion.Neutron spectrum regulation is the main technical approach for enhancing the production of medical isotopes,and it requires determining the optimal neutron spectrum and quantifying the values of neutrons in different energy regions.We calculated the neutron energy region values for 20 medical isotopes(14C,32P,47Sc,60Co,64Cu,67Cu,89Sr,90Y,99Mo,125I,131I,153Sm,161Tb,166Ho,177Lu,186Re,188Re,92Ir,225Ac,and 252Cf).The entire energy range was divided into 238 energy regions to improve the energy spectrum resolution,and both fast and thermal reactors were simulated to enhance universal applicability.A dataset of neutron energy region values across the entire energy range was built,which identifies the positive and negative-energy regions and guides the neutron spectrum regulation process during in-reactor medical isotope produc-tion.We conducted neutron spectrum regulation based on this dataset,which effectively improved the production efficiency of medical isotopes and demonstrated the correctness and feasibility of the dataset. 展开更多
关键词 Medical isotopes High-flux isotope reactor Neutron energy region value Spectrum regulation
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Zircon U-Pb Ages and Sr-Nd-Hf Isotopes Geochemistry of I-Type Granites in the Jiangda-Weixi Region,Eastern Xizang:Implications for the Tectonic Evolution of the Paleo-Tethyan Orogen 认领 引用
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作者 Rui Gao Tao Wu +3 位作者 Andrew C.Kerr Han Liu Long Xiao Wan Huang 《Journal of Earth Science》 SCIE CAS CSCD 2025年第6期2387-2410,共24页
Permian—Triassic granitoids are widely distributed along the Jinshajiang suture belt,eastern Xizang,and are regarded as the result of the tectonic-magmatic activity associated with the evolution of Paleo-Tethys Ocean... Permian—Triassic granitoids are widely distributed along the Jinshajiang suture belt,eastern Xizang,and are regarded as the result of the tectonic-magmatic activity associated with the evolution of Paleo-Tethys Ocean.This paper focuses on the high-K calc-alkaline I-type Rennong(~235 Ma)and Jiaduoling(~232 Ma)granitoid plutons,eastern Xizang,which are enriched in light rare earth elements(LREEs)and large ion lithophile elements(LILEs),but depleted in high field strength elements(HFSEs)with moderate-weak negative Eu anomalies(0.61–0.90).The Rennong granites are characterized by uniform zircon εHf(t)values(-7.3 to-3.5)and negative εNd(t)values(-7.6 to-5.7),with old two-stage Nd model ages(TDM2=1.51-1.46 Ga)and was likely formed by partial melting of the basement rocks,whereas the Jiaduoling rock samples have variable zircon εHf(t)values(-5.7 to+5.5)but negativeεNd(t)values(-7.6 to-7.7)and are proposed to be formed by hybridization of mantle-derived mafic magma,Rennong felsic magma and sediments.Mafic microgranular enclaves(MMEs)in the Jiaduoling granitic rocks,have similar zircon U-Pb ages(~237 Ma)and zircon εHf(t)values(-4.4 to+6.3)to the host rocks,indicating that zircons in the MMEs were actually xenocrysts that formed at an early stage in the granitic magma chamber.These results reveal that the break-off of the Jinshajiang oceanic slab beneath Changdu(Qamdo)-Simao Block was in a post-collisional setting,resulted in the upwelling of asthenosphere in the Late Triassic,and then,generated the wide-spread intermediate-felsic magmatism along the Jinshajing belt,including the Rennong and Jiaduoling plutons. 展开更多
关键词 Paleo-Tethys Ocean Jiangda(Jomda)-Weixi Sr-Nd-Hf isotopes I-type granite geochronology geochemistry
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Geochronology,Geochemistry and Sr-Nd-Pb Isotopes of the Early-Middle Jurassic Highly Fractionated Granites in Southern Jiangxi,and their Implications for the Rare-Earth Mineralization:Examples from the Muzishan,Xiahu,and Zudong Deposits 认领 引用
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作者 WANG Jiaxin FANG Xiang +4 位作者 CHU Kelei FAN Huihu ZHENG Wei HUANG Bin WU Dehai 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2025年第4期995-1012,共18页
The pervasively distributed granitoids in South China contributed greatly to regional polymetallic mineralization,including tungsten,tin,copper,gold,rare metals,and rare earth elements(REEs).To ascertain the dynamic b... The pervasively distributed granitoids in South China contributed greatly to regional polymetallic mineralization,including tungsten,tin,copper,gold,rare metals,and rare earth elements(REEs).To ascertain the dynamic backgrounds,rock types and genesis of the parent rocks related to the Early-Middle Jurassic ionic rare earth mineralization,typical deposits at Muzishan,Xiahu,and Zudong were investigated by conducting petrographic,geochronologic,whole-rock geochemical,and Sr-Nd-Pb isotope analyses,which found that the parent rocks from the Muzishan deposit were the A1-type K-feldspar granite(~195 Ma),from the Zudong deposit were the A2-type monzogranite(~171 Ma),and from the Xiahu deposit were the I-type monzogranite(~167 Ma).All the three granitic rocks underwent different degrees of fractionation,with the Xiahu granite experiencing the highest degree,followed by the Zudong granite,and the Muzishan granite undergoing the lowest degree.The Muzishan granite was concluded to be formed under an intraplate extensional tectonic regime influenced by the hotspots or the mantle plume.The Zudong granite was formed in a post-arc extensional setting related to subduction-collision-rollback of the paleo-Pacific Plate,which caused upwelling of the asthenosphere,thinning of the lithosphere,and partial melting of crustal materials.The Xiahu granite was generated under a transitional tectonic setting of extension and compression,triggered by delamination and rollback of the paleo-Pacific Plate. 展开更多
关键词 igneous rocks geochemistry A-type granite high fractionation tectonics Sr-Nd-Pb isotopes South China
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Strategies towards robust interpretations of Pb isotopes 认领 引用
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作者 J Liebmann B Ware +2 位作者 A Zametzer C.L Kirkland M.I.H.Hartnady 《Geoscience Frontiers》 SCIE CAS CSCD 2025年第2期99-115,共17页
Lead (Pb) isotopes can provide key information to address fundamental geologic problems related to the formation and evolution of rocky planets. The Pb isotope system supports a diversity of applications, as it provid... Lead (Pb) isotopes can provide key information to address fundamental geologic problems related to the formation and evolution of rocky planets. The Pb isotope system supports a diversity of applications, as it provides access to information on magma sources as well as geologic age. Consequently, a wide range of analytical techniques, data validation and interpretation strategies have been advanced across a range of Pb isotope studies. Given the multiple different Pb isotope pairs, reflecting different decay rates and ultimate parental isotope concentrations, Pb isotopes have been viewed as one of the more challenging isotope systems to comprehend. Here we provide an overview of the various analytical and interpretative approaches, for this system, and highlight their respective strengths in the context of applications, such as magma source tracking and model age determination. A discussion of different methods to determine magma source parameters (e.g., U/Pb ratio and model age) is presented, along with recommendations for data validation and reporting. A checklist for recommended data and metadata to report for Pb isotopes is provided. The aim of this contribution is to provide a framework that enables a robust interpretation of Pb isotope signatures, promoting data transparency and comparison across different analytical approaches. 展开更多
关键词 Pb isotopes Model ages Source tracking Best practice Data reporting
Geodynamic record of Rodinia breakup to Gondwana formation:Insights from bulk geochemistry,whole-rock Sr-Nd isotopes,and zircon U-Pb-Hf data of Katherina Ring Complex,Sinai Peninsula,Egypt 认领 引用
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作者 Mohamed Faisal Huan Li +6 位作者 Chao Sun Muhammad A.Gul Abdulgafar K.Amuda Wenbo Sun Jar Ullah Ibrahim H.Khalifa Sara Mustafa 《Geoscience Frontiers》 SCIE CAS CSCD 2025年第4期325-342,共18页
The Arabian-Nubian Shield(ANS)serves as a key geological archive,preserving the tectono-thermal evolution associated with the Rodinia breakup(∼900–800 Ma)and Gondwana formation(∼800–620 Ma).The Katherina Ring Comp... The Arabian-Nubian Shield(ANS)serves as a key geological archive,preserving the tectono-thermal evolution associated with the Rodinia breakup(∼900–800 Ma)and Gondwana formation(∼800–620 Ma).The Katherina Ring Complex(KRC),located in the Sinai Peninsula,Egypt(northern ANS),exemplifies continental growth through multistage magmatism and orogenesis,spanning the Tonian to Ediacaran periods(∼900–530 Ma).Despite its importance,debates persist regarding the nature,age,crustal characteristics,and magma source evolution of its constituent units.Situated in the northwestern part of the KRC,the Wadi Rofaiyed Cu deposit offers an exceptional natural laboratory for investigating continental crust formation during this interval,owing to its superb exposure and preservation.This study integrates detailed fieldwork,petrographic analyses,whole-rock geochemistry,Sr-Nd isotopes,and in situ zircon U-Pb-Lu-Hf isotopic data.It aims to(i)establish a robust chronological framework for the unmetamorphosed plutonic rocks of the KRC,(ii)advance the understanding of associated geodynamic processes,and(iii)elucidate the episodic magmatism events.The findings show that Wadi Rofaiyed juvenile crust developed in four main phases:(i)a subduction-accretionary phase(∼755 Ma)characterized by intense calc-alkaline magmatism,originating from the partial melting of mafic lower crust;(ii)a syn-collisional phase(∼630 Ma)occurred during the collision between the Saharan metacraton and the younger ANS crust,producing I-type granitoids formed through magma mixing and crustal anatexis;(iii)a post-collisional phase characterized by intermediate I-type(∼595 Ma)to felsic A-type alkaline magma(∼594 Ma),originated from the partial melting of the overthickened lower crust corresponding to lithospheric delamination;and(iv)an anorogenic phase(∼530 Ma)related to the final amalgamation of Greater Gondwana.Isotopic analyses across all four magmatic phases reveal low initial87Sr/86Sr(0.702648–0.703311)and positiveεHf(t)(+2.84 to+7.78)andεNd(t)(+2.61 to+5.21)values,consistent with lower crustal sources with depleted mantle-like signatures.The model ages(TDM2)for these magmatic rocks derived from zircon Hf(1.2–1.5 Ga)and whole-rock Nd isotopes(0.96–1.17 Ga)support a predominantly juvenile crustal origin.These findings underscore the multistage tectono-magmatic evolution of the northern ANS,advancing our understanding of obduction-accretion dynamics and crustal development during the Neoproterozoic. 展开更多
关键词 Arabian-Nubian Shield Egyptian Eastern Desert Katherina Ring Complex Neoproterozoic crustal evolution Sr-Nd isotopes Zircon U-Pb-Hf dating
Deep geological processes of the early Middle Jurassic granitic complexes in the Songjianghe area,Jiapigou-Haigou collage zone,Northeast China:Evidence from zircon U-Pb dating,elemental geochemistry and Sr-Nd-Hf isotopes 认领 引用
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作者 Xinwen Zhang Jinggui Sun +2 位作者 Zuochao Lin Shu Wang Yunpeng He 《Acta Geochimica》 EI CAS CSCD 2025年第6期1308-1327,共20页
The deep geologic processes between the Xing’an-Mongolian Orogenic Belt and the North China Craton in the Mesozoic are crucial to reveal the magmatic and tectonic evolution and their constraints on mineralization in ... The deep geologic processes between the Xing’an-Mongolian Orogenic Belt and the North China Craton in the Mesozoic are crucial to reveal the magmatic and tectonic evolution and their constraints on mineralization in the Jiapigou-Haigou collage zone.In this paper,We have presented the geochronology,geochemistry and Sr-Nd-Hf isotopic compositions of the Middle Jurassic granitic complexes in the Songjianghe area,Jilin Province.The granitic complexes can be categorized into four groups based on their geologic characteristics,with corresponding zircon U-Pb isotope ages of 177 Ma,172 Ma,169 Ma and 168-167 Ma,respectively.These granitoids exhibit calcalkaline to high-K calc-alkaline,metaluminous to weakly peraluminous Ⅰ-type characteristics,which show relative enrichment in LILEs(Rb,Sr,Ba)and depletion in HFSEs(Nb,Zr).Geochemical analyses reveal high initial87Sr/86Sr ratios of 0.70633-0.70740,coupled with lowεNd(t)values ranging from−10.65 to−13.23.The zircon analyses show similarly negativeεHf(t)values ranging from−16.9 to−3.2.The integrated elemental and Hf-Sr-Nd isotopic signatures demonstrate that the primitive magmas of the four group rocks were primarily derived from partial melting of thickened Archean lower crust,with the exception of the Group Ⅳ rocks,which exhibit significant evidence of crustal contamination.The residual mineral assemblages during the magma-forming process varied from amphibole to eclogite facies.These findings indicate that magmatism in the Songjianghe region likely resulted from the accretion and delamination of the Archean crust in the collage zone during the subduction of the Paleo-Pacific Plate beneath the Eurasian continent. 展开更多
关键词 U-Pb datings Elemental geochemistry and Sr-Nd-Hf isotopes Petrogenesis Middle Jurassic granitic complexes Deep geologic processes Songjianghe area
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Surface erosion thickness and oxygen isotope of the Early Jurassic lake water in northern Sichuan Basin,evidence from clumped isotopes of shell limestones 认领 引用
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作者 Ping-Ping Li Shi-Jie He +3 位作者 Zhan-Jie Xu Dai-Qin Jiang Hua-Yao Zou Fang Hao 《Petroleum Science》 SCIE EI CAS CSCD 2025年第10期3867-3879,共13页
Oxygen isotope(δ18O)of paleolake water is a key indicator for reconstructing the formation temperature and diagenetic history of lacustrine carbonate minerals.In this study,we use clumped isotopes(Δ47)of lacus... Oxygen isotope(δ18O)of paleolake water is a key indicator for reconstructing the formation temperature and diagenetic history of lacustrine carbonate minerals.In this study,we use clumped isotopes(Δ47)of lacustrine shell limestones to determine the surface erosion thickness and δ18O of Early Jurassic lake water in the northern Sichuan Basin.We analyzed nine shell limestone and seventeen shale samples from the Early Jurassic Da'anzhai Member(J1z4)in the Yuanba area.Whether the shell's shapes are well or partially preserved,the J1z4shell limestones in the Yuanba area show no significant recrystallization and dull cathodoluminescence.These characteristics suggest that the shell limestones did not undergo significant diagenetic alteration during late burial.The Δ47values of the J1z4shell limestones range from 0.448±0.005‰to 0.463±0.006‰,yielding clumped isotope temperature(TΔ47)of 64.4±0.8 to 69.7±1.4℃,which is significantly higher than the Early Jurassic paleotemperature.It suggests that the Δ47of shell limestones was altered by solid-state reordering,meaning the TΔ47does not reflect the initial formation temperatures.By integrating organic matter's maturation model(Easy%Ro)of coexisting shales with Δ47solid-state reordering model of calcite,we constrained the maximum burial temperature(~170℃)and the initial formation temperature(~28℃)of these shell limestones.Based on reported paleotemperature gradient,we estimated that the surface erosion thickness was about 1500 m.Furthermore,using the determined initial formation temperatures and conventional oxygen isotope thermometer,we determined that the δ18O values of the Early Jurassic lake water in the Sichuan Basin,which ranged from-10.8‰to-8.0‰(SMOW).The reconstructed paleo temperature and δ18O of lake water suggest that the Early Jurassic in the Sichuan Basin was warm and humid,which was favorable for the deposition of organic-rich lacustrine shale.The methods developed in this study,which employ Δ47of shell limestones to reconstruct the maximum burial temperature and paleolake environmental conditions,demonstrate broad applicability to the Sichuan Basin and similar lacustrine basins. 展开更多
关键词 Surface erosion thickness δ18O of Jurassic lake water Clumped isotopes Shell limestone Sichuan Basin
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Lithium isotopes in the geothermal waters of the India–Asia continental convergent margin:Source and evolution 认领 引用
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作者 Yinlei Hao Hui Zhou +5 位作者 Xingxing Kuang Qinghua Gong Yuqing Feng Meizhuang Zhu Nianqing Li Xiaoyan Shi 《Geoscience Frontiers》 SCIE CAS CSCD 2025年第2期429-452,共24页
Lithium(Li)in geothermal waters along the India–Asia continental convergent margin is a potential Li resource and plays an important role in the Li budget and Li isotopic composition(δ7Li)of rivers and oceans.How... Lithium(Li)in geothermal waters along the India–Asia continental convergent margin is a potential Li resource and plays an important role in the Li budget and Li isotopic composition(δ7Li)of rivers and oceans.However,its origins and behavior remain unclear.Here,we systematically investigated theδ7Li,water(δ18O andδ2H)and helium(3He/4He)isotopes of 21 geothermal water samples as well as a series of shallow groundwater and river water samples from southern Tibet and the Himalayas.Theδ7Li values of geothermal waters vary from+1.0‰to+14.3‰and are negatively correlated with the Li concentration(0.006–35.0 mg/L).For geothermal water with Li concentrations>5 mg/L,Li is sourced mainly from magmatic fluids exsolving from granitic magma chambers in the crust rather than the mantle,with contributions of 49.5%±3.2%to 85.5%±1.0%.Theδ7Li values of these Li-rich geothermal waters are relatively homogeneous and comparable to those of bulk granitic rocks.They are mainly controlled by the Li isotopic compositions of granitic magmatic fluids(−2.6‰to+5.6‰),and the dissolution of primary minerals and the precipitation of secondary minerals with minimal Li isotopic fractionation during high-temperature(174±5℃ to 315±6℃)water–granite interactions at deep geothermal reservoirs(4.4–7.9 km).For geothermal waters with Li concentrations<5 mg/L,Li originates primarily from water–granitic rock interactions(dominated by biotite dissolution)at 106±3℃ to 207±10℃,contributing approximately 85%±16%of the total Li.An integrated dissolution–precipitation–mixing model suggests that highδ7Li values in Li-depleted samples result from preferential incorporation of 6Li into secondary minerals at lower reservoir temperatures within shallower reservoirs(2.7–5.2 km)and mixing of shallow groundwater during the ascent of geothermal waters.This study provides new insights into the fluid geochemistry of crustal granitic magma chambers and highlights that Li-rich geothermal waters in Tibet are controlled by the existence of crustal granitic magma chambers and the scale of faults. 展开更多
关键词 Geothermal waters Lithium isotopes Granitic magma chamber India–Asia continental convergent margin Water–rock interaction
Source analysis of nitrate pollution in a typical tributary of the upper Yellow River using a combined approach of stable isotopes and DOM fluorescence characteristics 认领 引用
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作者 Bin Xu Duo Zhang +10 位作者 Ziyang Wang Jie Li Zhiling Du Longmian Wang Qingqing Pang Xiang Zhu Lei Xie Ran Tao Huili Meng Dongyan Pei Fuquan Peng 《River》 EI CSCD 2025年第4期566-578,共13页
Identifying the sources and characteristics of water pollution is essential for the protection and management of water environments.Nitrate(NO3-)is a key pollutant affecting water quality in the Qingshui River,a... Identifying the sources and characteristics of water pollution is essential for the protection and management of water environments.Nitrate(NO3-)is a key pollutant affecting water quality in the Qingshui River,a typical semi-arid tributary in the upper Yellow River basin.This study aimed to investigate the spatiotemporal patterns and sources of NO3-in the basin using an integrated analysis of hydrochemistry,stable isotopes,and dissolved organic matter(DOM)fluorescence.Hydrochemical results revealed that the water quality exhibited distinct seasonal variations,influenced by the unique hydrological and climatic conditions of the upper Yellow River.The surface water showed elevated concentrations of NO3-with limited denitrification,and NO3-accumulation was driven by multiple sources.Based on the dual isotopes(δ15N andδ18O)and the MixSIAR model,it was quantitatively determined that allochthonous inputs—including chemical nitrogen fertilizer,soil nitrogen,domestic sewage,and manure—constituted the primary sources of NO3-.DOM fluorescence analysis revealed active biological or microbial metabolic activities,while allochthonous DOM significantly contributed to NO3-contamination.Both the MixSIAR model and DOM fluorescence results confirmed that protein-like substances were mainly derived from domestic sewage,whereas humic-like substances originated from non-point source pollution in the study area.These findings demonstrate the feasibility of combining isotopic and DOM fluorescence approaches to trace NO3-sources in surface water.This integrated methodology can support the design of targeted zonal management strategies to protect the surface water environment and maintain sustainable socioeconomic systems in semi-arid regions. 展开更多
关键词 dissolved organic matter hydrochemistry nitrate source identification and apportionment stable isotopes
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Production of unknown neutron-deficient isotopes with Z=99-106 in multinucleon transfer reaction124Xe+249Cf 认领 引用
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作者 Na Tang Si-Ying Ma +2 位作者 Rong An Jing-Jing Li Feng-Shou Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2025年第3期95-104,共10页
The dinuclear system approach,coupled with the statistical decay model GEMINI++,was used to investigate multinucleon transfer reactions.Experimental production cross-sections in the reaction129Xe+248Cm were repr... The dinuclear system approach,coupled with the statistical decay model GEMINI++,was used to investigate multinucleon transfer reactions.Experimental production cross-sections in the reaction129Xe+248Cm were reproduced to assess the reliability of these theoretical models.The production of neutron-deficient transcalifornium nuclei with Z=99-106 was examined in multinucleon transfer reactions,including124Xe+248Cm,124Xe+249Cf,and129Xe+249Cf.Both the driving potential and the neutron-to-proton equilibration ratio were found to dominate the nucleon transfer process.The reaction124Xe+249Cf is proposed as a promising projectile-target combination for producing neutron-deficient isotopes with Z=99-106,with the optimal incident energy identified as Ec.m.=533.64 MeV.Production cross-sections of 25 unknown neutron-deficient trancalifornium isotopes with cross-sections greater than 1 pb were predicted. 展开更多
关键词 Multinucleon transfer reaction Dinuclear system Unknown neutron-deficient isotopes with Z=99-106
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