1.Objective,The Cretaceous succession is characteristic of the aeolian sedimentary system in the Ordos Basin,which is the major ore-bearing layer for the sandstone-type uranium deposits.Based on the research of paleon...1.Objective,The Cretaceous succession is characteristic of the aeolian sedimentary system in the Ordos Basin,which is the major ore-bearing layer for the sandstone-type uranium deposits.Based on the research of paleontology and magnetostratigraphy,formers believed it belonged to the Early Cretaceous(Huang YB,2010).However,the lack of intrusions or volcanic rocks for isotopic dating results in an unclear formation age for the Lower Cretaceous succession.Recently,tuffs were firstly discovered in the Luohandong Formation in the Zhenyuan area,Gansu Province,located in the southwestern Ordos Basin,China.The LA-ICP-MS zircon U-Pb dating of tuffs was carried out.The new ages can precisely constrain the depositional age of the Luohandong Formation and also provide significant indications for the study of regional volcanic activities,paleoclimate,basin evolution,and tectonic setting.展开更多
A simple method for the determination of Sc, Y and Ln in carbonate at sub μg·g -1 levels by ICP MS with inter elements matrix matched technique was developed. A series of matrix matched standard so...A simple method for the determination of Sc, Y and Ln in carbonate at sub μg·g -1 levels by ICP MS with inter elements matrix matched technique was developed. A series of matrix matched standard solution were prepared by adopting the normalized concentration values, which were calculated the statistic average compositions of reference values of REEs in carbonate standard reference materials. The matrix effects of Ca and Mg on REEs were studied in detail and the results show that the matrix effect of Ca and Mg can be ignored when the dilution factors are more than 1000. The combination of 115 In and 103 Rh as internal standard was selected to compensate the drift of analytical signals. The method proposed was applied to the analysis of ultra trace REEs in carbonate references materials GSR 6, GSR 12 and real samples.展开更多
Voluminous granitoids are widely distributed in the Langshan region,northeast of the Alxa block,and record the evolutionary processes of the southern Central Asian Orogenic Belt.The Dabashan pluton was emplaced into t...Voluminous granitoids are widely distributed in the Langshan region,northeast of the Alxa block,and record the evolutionary processes of the southern Central Asian Orogenic Belt.The Dabashan pluton was emplaced into the Paleoproterozoic Diebusige complex.Early Carboniferous zircon LA-ICP MS U-Pb ages were from 327 Ma to 346 Ma.The Dabashan pluton can be classified as monzogranite and syenogranite,and exhibits high K2 O contents and K2 O/Na2 O ratios,which reveal a high-K calc-alkaline nature.The samples display strongly fractionated REE patterns,and are enriched in large ion lithophile elements(LILE)relative to high field strength elements(HFSE).The Dabashan plutons display unusually high Ba(823–2817 ppm)and Sr(166–520 ppm)contents and K/Rb ratios(315–627),but low Rb/Ba ratios(0.02–0.14),and exhibit fertile zircon Hf isotopic compositions[εHf(t)=-14 to-20],which are comparable to those of typical high Ba–Sr granitoids.Based on the geochemical compositions of the samples,we suggest that subducted sediments and ancient crustal materials both played important roles in their generation.Basaltic melts were derived from partial melting of subcontinental lithophile mantle metasomatized by subducted sediment-related melts with residual garnet in the source,which caused partial melting of ancient lower crust.Magmas derived from underplating ascended and emplaced in the middle–upper crust at different depths.The resultant magmas experienced some degree of fractional crystallization during their ascent.Given these geochemical characteristics,together with regional tectonic,magmatic,and structure analysis data,an active continental margin environment is proposed for the generation of these rocks.展开更多
A 211 m depth ice core observation was carried out at the top of the Vestfonna Ice Cap in Nordaustlandet, Svalbard, Norway in 1995. Chronology of the ice core was determined by tritium analysis and comparison to the v...A 211 m depth ice core observation was carried out at the top of the Vestfonna Ice Cap in Nordaustlandet, Svalbard, Norway in 1995. Chronology of the ice core was determined by tritium analysis and comparison to the volcanic eruption of Laki; the resulting accumulation rate is 0.34 0.35 m water eq.·yr -1 for the last 400 year. Concentrations of Al, V, Cr, Fe, Cu, Zn, As, Ag, Cd, Pb and U in an ice core have been determined by an inductively coupled plasma mass spectrometry (ICP MS) with a desolvated micro concentric nebulizer, which is a recent development and can achieve high sensitivity with low uptake rate of 60 mL/min. The concentrations of Pb, Cu, and Zn had increased from 1940s declined from 1970s to present. However, the profiles of Pb, Cu, and Zn were different and they seem to be influenced by the difference of sources. Since the ratios between Cu, Pb, and Zn in Svalbard is similar to that in French Alps, the source area of these elements is estimated to be Europe.展开更多
To assess the potential health risks of mixed rare earths Changle for human embryo, whether it crosses placenta membrane or placenta barrier should be determined. In order to arrive at the aim placenta tissue was obs...To assess the potential health risks of mixed rare earths Changle for human embryo, whether it crosses placenta membrane or placenta barrier should be determined. In order to arrive at the aim placenta tissue was observed after contamination with optical and electron microscope to show distribution and destiny of mixed rare earth Changle in placenta tissue. Meanwhile the amount of rare earths in serum of pregnant rat, amniotic fluid and extract of embryo tissue were measured by using Inductively Coupled Plasma Mass Spectrometer (ICP MS). The rats were administered to 0 3, 2, 5 and 20 mg·kg -1 mixed rare earths Changle every day, respectively by oral from the 6th to 18th day after pregnancy. The results show that many particles are found in syncytiotrophoblast around capillaries of placental villi in contaminated groups under light microscope, and there are more particles following increased dose. It also was observed that some dense bodies with the envelope in placenta membrane and to difference extent damages the mitochondria crista within syncytiotrophoblast cytoplasm in contaminated groups under transmission electron microscope (TEM). Results of ICP MS assay indicate that the level of Ce increases with contamination dose in the serum of pregnant rats, and the level of total rare earth element remarkably rises in amniotic fluid and serum of pregnant rats for 20 mg·kg -1 group as compared with the control without change for the other groups.展开更多
Inductively coupled plasma_mass spectrometry (ICP_MS) is used to determine rare_earth elements abundances in fluid inclusions. Quartz separates from the Lannigou and Yata Carlin_type gold deposits, southwestern China,...Inductively coupled plasma_mass spectrometry (ICP_MS) is used to determine rare_earth elements abundances in fluid inclusions. Quartz separates from the Lannigou and Yata Carlin_type gold deposits, southwestern China, were prepared by the decrepitation_leach method. Leachates were analyzed by ICP_MS, using conventional sample introduction. The results demonstrate that the decrepitation_leach method, in combination with ICP_MS analysis of leachates, is effective for REE determination. The chondrite_normalized REE patterns of inclusion fluids for the Lannigou and Yata samples associated with gold mineralization are characterized by light rare_earth elements (LREE) enrichment, with a weak negative Ce anomaly and a positive or negative Eu anomaly, whereas the pattern for the Lannigou sample associated with late gold mineralization (quartz_calcite stage) is characterized by LREE enrichment relative to HREE, with negative Ce and Eu anomalies.展开更多
The Zheboshan gold deposit, which is located in the "Gold Triangle" area on the borders of Sichuan, Gansu and Shaanxi provinces, is a very complicated micro_fine disseminated gold deposit. Considering the IC...The Zheboshan gold deposit, which is located in the "Gold Triangle" area on the borders of Sichuan, Gansu and Shaanxi provinces, is a very complicated micro_fine disseminated gold deposit. Considering the ICP_MS measurements and Rb and Sr isotope data, it is suggested that the ore_forming materials may have come from the quartz_amphibole porphyrite dykes. It is also suggested that the age of ore deposit is generally consistent with the age of formation of the quartz_amphibole porphyrite. It is further deduced that the deposit is a magmatic hydrothermal ore deposit.展开更多
基金supported by the Science&Technology Fundamental Resources Investigation Program of China(2022FY101800)the National Science Foundation of China(92162212)the International Geoscience Programme(IGCP 675).
文摘1.Objective,The Cretaceous succession is characteristic of the aeolian sedimentary system in the Ordos Basin,which is the major ore-bearing layer for the sandstone-type uranium deposits.Based on the research of paleontology and magnetostratigraphy,formers believed it belonged to the Early Cretaceous(Huang YB,2010).However,the lack of intrusions or volcanic rocks for isotopic dating results in an unclear formation age for the Lower Cretaceous succession.Recently,tuffs were firstly discovered in the Luohandong Formation in the Zhenyuan area,Gansu Province,located in the southwestern Ordos Basin,China.The LA-ICP-MS zircon U-Pb dating of tuffs was carried out.The new ages can precisely constrain the depositional age of the Luohandong Formation and also provide significant indications for the study of regional volcanic activities,paleoclimate,basin evolution,and tectonic setting.
文摘A simple method for the determination of Sc, Y and Ln in carbonate at sub μg·g -1 levels by ICP MS with inter elements matrix matched technique was developed. A series of matrix matched standard solution were prepared by adopting the normalized concentration values, which were calculated the statistic average compositions of reference values of REEs in carbonate standard reference materials. The matrix effects of Ca and Mg on REEs were studied in detail and the results show that the matrix effect of Ca and Mg can be ignored when the dilution factors are more than 1000. The combination of 115 In and 103 Rh as internal standard was selected to compensate the drift of analytical signals. The method proposed was applied to the analysis of ultra trace REEs in carbonate references materials GSR 6, GSR 12 and real samples.
基金supported by the National Key Research and Development Program of China from the Ministry of ScienceandTechnologyofChina(No.2017YFC0601301)the National Natural Science Foundation of China(41502214,41230207 and 41572190)+5 种基金the Outlay Research Fund of Institute of Geology,Chinese Academy of Geological Sciences(J1706)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB18020203)the CPSF-CAS Joint Foundation for Excellent Postdoctoral Fellows(Grant no.2015LH0049)the China Postdoctoral Foundation funded project(2016M590990)the Key Research Program of Frontier Sciences,CAS(QYZDJSSW-SYS012)China Geological Survey(12120115069601)
文摘Voluminous granitoids are widely distributed in the Langshan region,northeast of the Alxa block,and record the evolutionary processes of the southern Central Asian Orogenic Belt.The Dabashan pluton was emplaced into the Paleoproterozoic Diebusige complex.Early Carboniferous zircon LA-ICP MS U-Pb ages were from 327 Ma to 346 Ma.The Dabashan pluton can be classified as monzogranite and syenogranite,and exhibits high K2 O contents and K2 O/Na2 O ratios,which reveal a high-K calc-alkaline nature.The samples display strongly fractionated REE patterns,and are enriched in large ion lithophile elements(LILE)relative to high field strength elements(HFSE).The Dabashan plutons display unusually high Ba(823–2817 ppm)and Sr(166–520 ppm)contents and K/Rb ratios(315–627),but low Rb/Ba ratios(0.02–0.14),and exhibit fertile zircon Hf isotopic compositions[εHf(t)=-14 to-20],which are comparable to those of typical high Ba–Sr granitoids.Based on the geochemical compositions of the samples,we suggest that subducted sediments and ancient crustal materials both played important roles in their generation.Basaltic melts were derived from partial melting of subcontinental lithophile mantle metasomatized by subducted sediment-related melts with residual garnet in the source,which caused partial melting of ancient lower crust.Magmas derived from underplating ascended and emplaced in the middle–upper crust at different depths.The resultant magmas experienced some degree of fractional crystallization during their ascent.Given these geochemical characteristics,together with regional tectonic,magmatic,and structure analysis data,an active continental margin environment is proposed for the generation of these rocks.
文摘A 211 m depth ice core observation was carried out at the top of the Vestfonna Ice Cap in Nordaustlandet, Svalbard, Norway in 1995. Chronology of the ice core was determined by tritium analysis and comparison to the volcanic eruption of Laki; the resulting accumulation rate is 0.34 0.35 m water eq.·yr -1 for the last 400 year. Concentrations of Al, V, Cr, Fe, Cu, Zn, As, Ag, Cd, Pb and U in an ice core have been determined by an inductively coupled plasma mass spectrometry (ICP MS) with a desolvated micro concentric nebulizer, which is a recent development and can achieve high sensitivity with low uptake rate of 60 mL/min. The concentrations of Pb, Cu, and Zn had increased from 1940s declined from 1970s to present. However, the profiles of Pb, Cu, and Zn were different and they seem to be influenced by the difference of sources. Since the ratios between Cu, Pb, and Zn in Svalbard is similar to that in French Alps, the source area of these elements is estimated to be Europe.
文摘To assess the potential health risks of mixed rare earths Changle for human embryo, whether it crosses placenta membrane or placenta barrier should be determined. In order to arrive at the aim placenta tissue was observed after contamination with optical and electron microscope to show distribution and destiny of mixed rare earth Changle in placenta tissue. Meanwhile the amount of rare earths in serum of pregnant rat, amniotic fluid and extract of embryo tissue were measured by using Inductively Coupled Plasma Mass Spectrometer (ICP MS). The rats were administered to 0 3, 2, 5 and 20 mg·kg -1 mixed rare earths Changle every day, respectively by oral from the 6th to 18th day after pregnancy. The results show that many particles are found in syncytiotrophoblast around capillaries of placental villi in contaminated groups under light microscope, and there are more particles following increased dose. It also was observed that some dense bodies with the envelope in placenta membrane and to difference extent damages the mitochondria crista within syncytiotrophoblast cytoplasm in contaminated groups under transmission electron microscope (TEM). Results of ICP MS assay indicate that the level of Ce increases with contamination dose in the serum of pregnant rats, and the level of total rare earth element remarkably rises in amniotic fluid and serum of pregnant rats for 20 mg·kg -1 group as compared with the control without change for the other groups.
文摘Inductively coupled plasma_mass spectrometry (ICP_MS) is used to determine rare_earth elements abundances in fluid inclusions. Quartz separates from the Lannigou and Yata Carlin_type gold deposits, southwestern China, were prepared by the decrepitation_leach method. Leachates were analyzed by ICP_MS, using conventional sample introduction. The results demonstrate that the decrepitation_leach method, in combination with ICP_MS analysis of leachates, is effective for REE determination. The chondrite_normalized REE patterns of inclusion fluids for the Lannigou and Yata samples associated with gold mineralization are characterized by light rare_earth elements (LREE) enrichment, with a weak negative Ce anomaly and a positive or negative Eu anomaly, whereas the pattern for the Lannigou sample associated with late gold mineralization (quartz_calcite stage) is characterized by LREE enrichment relative to HREE, with negative Ce and Eu anomalies.
文摘The Zheboshan gold deposit, which is located in the "Gold Triangle" area on the borders of Sichuan, Gansu and Shaanxi provinces, is a very complicated micro_fine disseminated gold deposit. Considering the ICP_MS measurements and Rb and Sr isotope data, it is suggested that the ore_forming materials may have come from the quartz_amphibole porphyrite dykes. It is also suggested that the age of ore deposit is generally consistent with the age of formation of the quartz_amphibole porphyrite. It is further deduced that the deposit is a magmatic hydrothermal ore deposit.
