Groundwater serves as an important water source for residents in and around mining areas.To achieve scientific planning and efficient utilization of water resources in mining areas,it is essential to figure out the ch...Groundwater serves as an important water source for residents in and around mining areas.To achieve scientific planning and efficient utilization of water resources in mining areas,it is essential to figure out the chemical formation process and the ground water sulfur cycle that transpire after the coal mining activities.Based on studies of hydrochemistry and D,^(18)O-H_(2)O,^(34)S-SO_(4)isotopes,this study applied principal component analysis,ion ratio and other methods in its attempts to reveal the hydrogeochemical action and sulfur cycle in the subsidence area of Pingyu mining area.The study discovered that,in the studied area,precipitation provides the major supply of groundwater and the main water chemistry effects are dominated by oxidation dissolution of sulfide minerals as well as the dissolution of carbonate and silicate rocks.The sulfate in groundwater primarily originates from oxidation and dissolution of sulfide minerals in coal-bearing strata and human activities.The mixed sulfate formed by the oxidation of sulfide minerals and by human activities continuously recharges the groundwater,promoting the dissolution of carbonate rock and silicate rock in the process.展开更多
A multi-isotope approach and mixing model were combined to identify spatial and seasonal variations of sources,and their proportional contribution to nitrate in the Hutuo River alluvial-pluvial fan region.The results ...A multi-isotope approach and mixing model were combined to identify spatial and seasonal variations of sources,and their proportional contribution to nitrate in the Hutuo River alluvial-pluvial fan region.The results showed that the NO3- concentration was significantly higher in the Hutuo River valley plain(178.7 mg/L) region than that in the upper and central pluvial fans of the Hutuo River(82.1 mg/L and 71.0 mg/L,respectively)and in the river(17.0 mg/L).Different land use types had no significant effect on the groundwater nitrate concentration.Based on a multi-isotope approach,we confirmed that the main sources of groundwater nitrate in different land use areas were domestic sewage and manure,followed by soil nitrogen,ammonia fertilizer,nitrate fertilizer and rainwater,and there were no significant spatial or seasonal variations.Combining δ^15N-NO3,δ^18O-NO3- and δ^37Cl results can increase the accuracy of traceability.Nitrification could be the most important nitrogen migration and transformation process,and denitrification did not significantly affected the isotopic composition of the nitrate.The SIAR model outputs revealed that the main nitrate pollution sources in groundwater and river water were domestic sewage and manure,accounting for 55.9%-61.0% and 22.6%(dry season),50.3%-60.4% and 34.1%(transition season),42.7%-47.6% and 35.6%(wet season 2016) and 45.9%-46.7% and 38.4%(wet season 2017),respectively.This work suggests that the random discharge and disposal of domestic sewage and manure should be the first target for control in order to prevent further nitrate contamination of the water environment.展开更多
The determination of the geographical origin as well as the adulteration of natural products is a technical problem due to similar chemical composition between an adulterant and the original. It is assumed that tartar...The determination of the geographical origin as well as the adulteration of natural products is a technical problem due to similar chemical composition between an adulterant and the original. It is assumed that tartaric acid comes from natural sources, however there is no specific regulation for this claim. This paper describes the use of isotope mass spectrometry associated with chemometrics to classify different samples of tartaric acid. The results showed that the variables δ^13C, δ^18O and δ^2H allowed the discrimination of tartaric acid samples by geographical origin and production method. By using a combination of chemometfic analysis it was possible to confirm a notoriousseparation of the samples. Thus, this is a promising method to be applied in the quality control and authenticity of tartaric acid.展开更多
Most giant porphyry-skarn Cu-Au ore systems are associated with either the metasomatic mantle wedge,formed by the dehydration of subducting oceanic crust,or the melting of Cu-rich juvenile lower crust.The ore-forming ...Most giant porphyry-skarn Cu-Au ore systems are associated with either the metasomatic mantle wedge,formed by the dehydration of subducting oceanic crust,or the melting of Cu-rich juvenile lower crust.The ore-forming parent rocks are typically depleted adakites.In contrast,parent rocks in intracontinental Cu-Au ore systems exhibit enriched isotopic compositions,yet their formation mechanisms and deep processes remain unclear.To address this,our study focuses on the central Yangtze River ore belt(CYROB)and adjacent areas.By compiling regional petrological and chronological data,we conducted multi-isotope tracing and Hf isotope mapping,integrated with regional seismic velocity tomography and magnetotelluric detection results,to reconstruct the lithospheric architecture and its evolutionary processes.Our findings indicate that the CYROB underwent significant crustal accretion during the Meso-and Neo-proterozoic,forming a juvenile crust.In the Late Mesozoic,the crust experienced polygenetic reworking,through two distinct periods(156–136 Ma and 136–120 Ma).During the transition from the Late Jurassic to the Early Cretaceous(156–140 Ma),in the area near and north of the Gaotan fault,lithospheric delamination in an extensional setting facilitated mantle convection and partial melting of enriched lithospheric mantle.This process modified the pre-existing juvenile lower crust,leading to the formation of adakites with slightly negativeεHf values(-5 to 0)and associated porphyry-skarn Cu-Au deposits.Concurrently,ascent of adakitic magma occasionally incorporated W-rich middle-to-upper crustal materials,enriching the melts in W and forming localized small-to medium-sized skarn W deposits.During 140–136 Ma,with the continued relaxation of lithospheric stress,a more intense modification of the lower crust by enriched mantle occurred west of Anqing and north of Qingyang.This led to the formation of adakic magmas with strongly negativeεHfvalues(-24 to-8)and related skarn Cu-Fe deposits.To the south of the Jiangnan fault,where the crust was deeper,mantle convection induced the remelting of Proterozoic reworked crust,releasing W and Mo into crust-derived melts,ultimately forming a series of large-and medium-sized porphyry-skarn W-Mo deposits.During the late period(136–120 Ma),progressive lithospheric extension triggered large-scale lithospheric delamination and oblique asthenospheric upwelling from the southeast to the northwest,further modifying the lower crust.The remelting of reworked crust with input from depleted mantle materials,led to the formation of extensive alkali-rich granitic batholiths.This study demonstrates that,under the extensional regime of the Late Mesozoic,the polygenic reworking of juvenile crust and the remelting of previously reworked crust—driven by ongoing lithosphere-scale delamination and asthenospheric upwelling—played a key role in controlling the temporal and spatial distribution of metal ore systems in the CYROB and adjacent areas.展开更多
Zircon U-Pb thermal ionization mass-spectrometer (TIMS) and secondary ion mass-spectrometer (SIMS) dating, mica and amphibole 40Ar-39Ar dating and mineral Sm-Nd isotopic compositions of Huangzhen low temperature eclog...Zircon U-Pb thermal ionization mass-spectrometer (TIMS) and secondary ion mass-spectrometer (SIMS) dating, mica and amphibole 40Ar-39Ar dating and mineral Sm-Nd isotopic compositions of Huangzhen low temperature eclogite and country granitic gneiss are carried out. The zircon U-Pb weighted average SIMS age is (231.6?9.7) Ma for one eclogite. The mica 40Ar-39Ar isochron age is (232.6?2.1) Ma and the lowest plateau age is (221.7?2.4) Ma from same sample. U-Pb TIMS concordant ages from other eclogite zircons are from (221.3?1.4) Ma to (222.5?2.3) Ma. U-Pb SIMS low intercept age from country granitic gneiss is (221?35) Ma. The retrograde amphibole 40Ar-39Ar isochron age is (205.9?1.0) Ma. Except for mica, which may contain excess 40Ar, all the ages represent peak and retrograde metamorphism of low temperature eclogites. It is indicated that the Huangzhen low temperature eclogites differ from Xiongdian low temperature eclogites of north of the Northern Dabie Terrain in metamorphic ages. Huangzhen low temperature eclogites share one coherent HP-UHP terrain with high temperature eclogites from Southern Dabie Terrain and they may have differences in subduction depth and cooling rates during exhumation.展开更多
基金supported by Geological Research Project of the Construction Management Bureau of the Middle Route of the South to North Water Diversion Project(ZXJ/HN/YW/GC-2020037)。
文摘Groundwater serves as an important water source for residents in and around mining areas.To achieve scientific planning and efficient utilization of water resources in mining areas,it is essential to figure out the chemical formation process and the ground water sulfur cycle that transpire after the coal mining activities.Based on studies of hydrochemistry and D,^(18)O-H_(2)O,^(34)S-SO_(4)isotopes,this study applied principal component analysis,ion ratio and other methods in its attempts to reveal the hydrogeochemical action and sulfur cycle in the subsidence area of Pingyu mining area.The study discovered that,in the studied area,precipitation provides the major supply of groundwater and the main water chemistry effects are dominated by oxidation dissolution of sulfide minerals as well as the dissolution of carbonate and silicate rocks.The sulfate in groundwater primarily originates from oxidation and dissolution of sulfide minerals in coal-bearing strata and human activities.The mixed sulfate formed by the oxidation of sulfide minerals and by human activities continuously recharges the groundwater,promoting the dissolution of carbonate rock and silicate rock in the process.
基金supported by the Natural Science Foundation of Hebei Province of China,China (No.D2015504008)the Fundamental Research Funds for the Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,China (No.SK201707)Projects of China Geological Survey,China (No.DD20190331).
文摘A multi-isotope approach and mixing model were combined to identify spatial and seasonal variations of sources,and their proportional contribution to nitrate in the Hutuo River alluvial-pluvial fan region.The results showed that the NO3- concentration was significantly higher in the Hutuo River valley plain(178.7 mg/L) region than that in the upper and central pluvial fans of the Hutuo River(82.1 mg/L and 71.0 mg/L,respectively)and in the river(17.0 mg/L).Different land use types had no significant effect on the groundwater nitrate concentration.Based on a multi-isotope approach,we confirmed that the main sources of groundwater nitrate in different land use areas were domestic sewage and manure,followed by soil nitrogen,ammonia fertilizer,nitrate fertilizer and rainwater,and there were no significant spatial or seasonal variations.Combining δ^15N-NO3,δ^18O-NO3- and δ^37Cl results can increase the accuracy of traceability.Nitrification could be the most important nitrogen migration and transformation process,and denitrification did not significantly affected the isotopic composition of the nitrate.The SIAR model outputs revealed that the main nitrate pollution sources in groundwater and river water were domestic sewage and manure,accounting for 55.9%-61.0% and 22.6%(dry season),50.3%-60.4% and 34.1%(transition season),42.7%-47.6% and 35.6%(wet season 2016) and 45.9%-46.7% and 38.4%(wet season 2017),respectively.This work suggests that the random discharge and disposal of domestic sewage and manure should be the first target for control in order to prevent further nitrate contamination of the water environment.
文摘The determination of the geographical origin as well as the adulteration of natural products is a technical problem due to similar chemical composition between an adulterant and the original. It is assumed that tartaric acid comes from natural sources, however there is no specific regulation for this claim. This paper describes the use of isotope mass spectrometry associated with chemometrics to classify different samples of tartaric acid. The results showed that the variables δ^13C, δ^18O and δ^2H allowed the discrimination of tartaric acid samples by geographical origin and production method. By using a combination of chemometfic analysis it was possible to confirm a notoriousseparation of the samples. Thus, this is a promising method to be applied in the quality control and authenticity of tartaric acid.
基金jointly funded by the National Key Technologies Research and Development Program(Grant Nos.2019YFA0708603,2023YFF0804203)the China Geological Survey(Grant No.DD20243510)+2 种基金the Scientific Research Fund Project of BGRIMM Technology Group(Grant No.JTKY202427822)the National Natural Science Foundation of China(Grant No.42073042)the Basic Scientific Research Fund of the Institute of Geology,Chinese Academy of Geological Sciences(Grant No.J2402)。
文摘Most giant porphyry-skarn Cu-Au ore systems are associated with either the metasomatic mantle wedge,formed by the dehydration of subducting oceanic crust,or the melting of Cu-rich juvenile lower crust.The ore-forming parent rocks are typically depleted adakites.In contrast,parent rocks in intracontinental Cu-Au ore systems exhibit enriched isotopic compositions,yet their formation mechanisms and deep processes remain unclear.To address this,our study focuses on the central Yangtze River ore belt(CYROB)and adjacent areas.By compiling regional petrological and chronological data,we conducted multi-isotope tracing and Hf isotope mapping,integrated with regional seismic velocity tomography and magnetotelluric detection results,to reconstruct the lithospheric architecture and its evolutionary processes.Our findings indicate that the CYROB underwent significant crustal accretion during the Meso-and Neo-proterozoic,forming a juvenile crust.In the Late Mesozoic,the crust experienced polygenetic reworking,through two distinct periods(156–136 Ma and 136–120 Ma).During the transition from the Late Jurassic to the Early Cretaceous(156–140 Ma),in the area near and north of the Gaotan fault,lithospheric delamination in an extensional setting facilitated mantle convection and partial melting of enriched lithospheric mantle.This process modified the pre-existing juvenile lower crust,leading to the formation of adakites with slightly negativeεHf values(-5 to 0)and associated porphyry-skarn Cu-Au deposits.Concurrently,ascent of adakitic magma occasionally incorporated W-rich middle-to-upper crustal materials,enriching the melts in W and forming localized small-to medium-sized skarn W deposits.During 140–136 Ma,with the continued relaxation of lithospheric stress,a more intense modification of the lower crust by enriched mantle occurred west of Anqing and north of Qingyang.This led to the formation of adakic magmas with strongly negativeεHfvalues(-24 to-8)and related skarn Cu-Fe deposits.To the south of the Jiangnan fault,where the crust was deeper,mantle convection induced the remelting of Proterozoic reworked crust,releasing W and Mo into crust-derived melts,ultimately forming a series of large-and medium-sized porphyry-skarn W-Mo deposits.During the late period(136–120 Ma),progressive lithospheric extension triggered large-scale lithospheric delamination and oblique asthenospheric upwelling from the southeast to the northwest,further modifying the lower crust.The remelting of reworked crust with input from depleted mantle materials,led to the formation of extensive alkali-rich granitic batholiths.This study demonstrates that,under the extensional regime of the Late Mesozoic,the polygenic reworking of juvenile crust and the remelting of previously reworked crust—driven by ongoing lithosphere-scale delamination and asthenospheric upwelling—played a key role in controlling the temporal and spatial distribution of metal ore systems in the CYROB and adjacent areas.
基金supported by the National Natural Science Foundation of China(Grant Nos.40273028 and 40033010)the State Key Basic Research Project(Grant No.G1999075503).
文摘Zircon U-Pb thermal ionization mass-spectrometer (TIMS) and secondary ion mass-spectrometer (SIMS) dating, mica and amphibole 40Ar-39Ar dating and mineral Sm-Nd isotopic compositions of Huangzhen low temperature eclogite and country granitic gneiss are carried out. The zircon U-Pb weighted average SIMS age is (231.6?9.7) Ma for one eclogite. The mica 40Ar-39Ar isochron age is (232.6?2.1) Ma and the lowest plateau age is (221.7?2.4) Ma from same sample. U-Pb TIMS concordant ages from other eclogite zircons are from (221.3?1.4) Ma to (222.5?2.3) Ma. U-Pb SIMS low intercept age from country granitic gneiss is (221?35) Ma. The retrograde amphibole 40Ar-39Ar isochron age is (205.9?1.0) Ma. Except for mica, which may contain excess 40Ar, all the ages represent peak and retrograde metamorphism of low temperature eclogites. It is indicated that the Huangzhen low temperature eclogites differ from Xiongdian low temperature eclogites of north of the Northern Dabie Terrain in metamorphic ages. Huangzhen low temperature eclogites share one coherent HP-UHP terrain with high temperature eclogites from Southern Dabie Terrain and they may have differences in subduction depth and cooling rates during exhumation.
