The mantle xenoliths in the Quaternary ChangbaishanVolcano in southern Jilin Province contain spinel-facies lherzolites. The equilibration temperatures for these samples range from 902℃ to 1064℃ based on the two-pyr...The mantle xenoliths in the Quaternary ChangbaishanVolcano in southern Jilin Province contain spinel-facies lherzolites. The equilibration temperatures for these samples range from 902℃ to 1064℃ based on the two-pyroxene thermometer of Brey and Kohler （1990）, and using the oxybarometry of Nell and Wood （1991）, the oxidation state was estimated from FMQ-1.32 to -0.38 with an average value of FMQ-0.81 （n = 8）, which is comparable to that of abyssal peridotites and the asthenospheric mantle. ThefO2 values of peridotites, together with their bulk rock compositions （e.g., Mg#, Al2O3, CaO, Ni, Co, Cr） and mineral compositions （e.g., Mg# of olivine and pyroxene, Cr# [=Cr/ [Cr＋Al]] and Mg# [=Mg/[Mg＋Fe2~] of spinel）, suggest that the present-day subcontinental lithospheric mantle （SCLM） beneath the Changbaishan Volcano most likely formed from an upwelling asthenosphere at some time after the late Mesozoic and has undergone a low degree of partial melting. The studied lherzolite xenoliths show low concentrations of S, Cu, and platinum group elements （PGE）, which plot a flat pattern on primitive-mantle normalized diagram. Very low concentrations in our samples suggest that PGEs occur as alloys or hosted by silicate and oxide minerals. The compositions of the studied samples are similar to those of peridotite xenoliths in the Longgang volcanic field （LVF） in their mineralogy and bulk rock compositions including the abundance of chalcophile and siderophile elements. However, they are distinctly different from those of peridotite xenoliths in other areas of the North China Craton （NCC） in terms of Cu, S and PGE. Our data suggest that the SCLM underlying the northeastern part of the NCC may represent a distinct unit of the newly formed lithospberic mantle.展开更多
Chalcophile elements are a group of elements with strong affinities for sulfides and metals.Their distribution among the core,mantle,and crust of terrestrial planets provides valuable insights into planetary formation...Chalcophile elements are a group of elements with strong affinities for sulfides and metals.Their distribution among the core,mantle,and crust of terrestrial planets provides valuable insights into planetary formation and evolution,such as terrestrial accretion,core-mantle differentiation,and crustmantle interaction.Understanding the migration and cycling of chalcophile elements among Earth's different layers,and the mechanisms for their anomalous enrichment and mineralization,is crucial for unraveling the formation of strategic mineral resources.Many chalcophile elements are volatile heavy metals and can be released during volcanic eruption and accumulated in the Earth's surface,posing serious ecological risks and even leading to environmental collapse and mass extinction.Despite their importance and prior study,the distribution,transport,enrichment,and release of chalcophile elements within Earth's different reservoirs remain poorly understood,limiting their broader applications.In this review,we summarize the fundamental geochemical behavior of chalcophile elements,with a focus on their distribution and recycling throughout Earth's core,mantle,and crust.We highlight several representative applications of chalcophile element systematics,including early terrestrial accretion,mantle-crust differentiation,subduction recycling,and associated impacts for mineral resources and environments.We suggest that further study of the geochemical behavior of chalcophile elements within Earth's complex systems will be of great importance for the terrestrial evolution and its consequences for mineral resources and environment.展开更多
The Nigerian oil sands represent the largest oil sand deposit in Africa, yet there is little published information on the distribution and potential health and ecological risks of trace elements in the oil resource. I...The Nigerian oil sands represent the largest oil sand deposit in Africa, yet there is little published information on the distribution and potential health and ecological risks of trace elements in the oil resource. In the present study, we investigated the distribution pattern of 18trace elements(including biophile and chalcophile elements) as well as the estimated risks associated with exposure to these elements. The results of the study indicated that Fe was the most abundant element, with a mean concentration of 22,131 mg/kg while Br had the lowest mean concentration of 48 mg/kg. The high occurrence of Fe and Ti suggested a possible occurrence of ilmenite(Fe TiO_(3)) in the oil sands. Source apportionment using positive matrix factorization showed that the possible sources of detected elements in the oil sands were geogenic, metal production, and crustal. The contamination factor, geo-accumulation index, modified degree of contamination, pollution load index, and Nemerow pollution index indicated that the oil sands are heavily polluted by the elements. Health risk assessment showed that children were relatively more susceptible to the potentially toxic elements in the oil sands principally via ingestion exposure route(HQ > 1E-04). Cancer risks from inhalation are unlikely due to CR < 1E-06 but ingestion and dermal contact pose severe risks(CR > 1E-04). The high concentrations of the elements pose serious threats due to the potential for atmospheric transport, bioaccessibility, and bioavailability.展开更多
The geochemical classification proposed by Goldschmidt was based on meteoritic analysis and elemental partition in blast furnace. There are many surprises when applied to the discussion of natural occurrences. A modif...The geochemical classification proposed by Goldschmidt was based on meteoritic analysis and elemental partition in blast furnace. There are many surprises when applied to the discussion of natural occurrences. A modified classification of ele- ments based on basic chemical properties and their occurrences. A modified classification of elements based on basic chemical properties and their occurrences in nature is, therefore, proposed for students learning geochemistry and geologists working in the field. Elements are classified into six groups including lithophile, oxyphile, siderophile, chalcophile, biophile, and at- mophile elements. Five terms are taken from Goldshcmidt’s original classification. Oxyphile is a new term.展开更多
基金supported by grants from National Natural Science Foundation of China (Nos.40873016,41173034,90814003)supportedby a grant from China Geological Survey (No.1212011121088)
文摘The mantle xenoliths in the Quaternary ChangbaishanVolcano in southern Jilin Province contain spinel-facies lherzolites. The equilibration temperatures for these samples range from 902℃ to 1064℃ based on the two-pyroxene thermometer of Brey and Kohler （1990）, and using the oxybarometry of Nell and Wood （1991）, the oxidation state was estimated from FMQ-1.32 to -0.38 with an average value of FMQ-0.81 （n = 8）, which is comparable to that of abyssal peridotites and the asthenospheric mantle. ThefO2 values of peridotites, together with their bulk rock compositions （e.g., Mg#, Al2O3, CaO, Ni, Co, Cr） and mineral compositions （e.g., Mg# of olivine and pyroxene, Cr# [=Cr/ [Cr＋Al]] and Mg# [=Mg/[Mg＋Fe2~] of spinel）, suggest that the present-day subcontinental lithospheric mantle （SCLM） beneath the Changbaishan Volcano most likely formed from an upwelling asthenosphere at some time after the late Mesozoic and has undergone a low degree of partial melting. The studied lherzolite xenoliths show low concentrations of S, Cu, and platinum group elements （PGE）, which plot a flat pattern on primitive-mantle normalized diagram. Very low concentrations in our samples suggest that PGEs occur as alloys or hosted by silicate and oxide minerals. The compositions of the studied samples are similar to those of peridotite xenoliths in the Longgang volcanic field （LVF） in their mineralogy and bulk rock compositions including the abundance of chalcophile and siderophile elements. However, they are distinctly different from those of peridotite xenoliths in other areas of the North China Craton （NCC） in terms of Cu, S and PGE. Our data suggest that the SCLM underlying the northeastern part of the NCC may represent a distinct unit of the newly formed lithospberic mantle.
基金supported by the Hubei Provincial Natural Science Foundation of China(Grant No.2025AFA005)National Natural Science Foundation of China(Grant No.42273023)State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Grant No.GPMR-2025-QT01)。
文摘Chalcophile elements are a group of elements with strong affinities for sulfides and metals.Their distribution among the core,mantle,and crust of terrestrial planets provides valuable insights into planetary formation and evolution,such as terrestrial accretion,core-mantle differentiation,and crustmantle interaction.Understanding the migration and cycling of chalcophile elements among Earth's different layers,and the mechanisms for their anomalous enrichment and mineralization,is crucial for unraveling the formation of strategic mineral resources.Many chalcophile elements are volatile heavy metals and can be released during volcanic eruption and accumulated in the Earth's surface,posing serious ecological risks and even leading to environmental collapse and mass extinction.Despite their importance and prior study,the distribution,transport,enrichment,and release of chalcophile elements within Earth's different reservoirs remain poorly understood,limiting their broader applications.In this review,we summarize the fundamental geochemical behavior of chalcophile elements,with a focus on their distribution and recycling throughout Earth's core,mantle,and crust.We highlight several representative applications of chalcophile element systematics,including early terrestrial accretion,mantle-crust differentiation,subduction recycling,and associated impacts for mineral resources and environments.We suggest that further study of the geochemical behavior of chalcophile elements within Earth's complex systems will be of great importance for the terrestrial evolution and its consequences for mineral resources and environment.
文摘The Nigerian oil sands represent the largest oil sand deposit in Africa, yet there is little published information on the distribution and potential health and ecological risks of trace elements in the oil resource. In the present study, we investigated the distribution pattern of 18trace elements(including biophile and chalcophile elements) as well as the estimated risks associated with exposure to these elements. The results of the study indicated that Fe was the most abundant element, with a mean concentration of 22,131 mg/kg while Br had the lowest mean concentration of 48 mg/kg. The high occurrence of Fe and Ti suggested a possible occurrence of ilmenite(Fe TiO_(3)) in the oil sands. Source apportionment using positive matrix factorization showed that the possible sources of detected elements in the oil sands were geogenic, metal production, and crustal. The contamination factor, geo-accumulation index, modified degree of contamination, pollution load index, and Nemerow pollution index indicated that the oil sands are heavily polluted by the elements. Health risk assessment showed that children were relatively more susceptible to the potentially toxic elements in the oil sands principally via ingestion exposure route(HQ > 1E-04). Cancer risks from inhalation are unlikely due to CR < 1E-06 but ingestion and dermal contact pose severe risks(CR > 1E-04). The high concentrations of the elements pose serious threats due to the potential for atmospheric transport, bioaccessibility, and bioavailability.
文摘The geochemical classification proposed by Goldschmidt was based on meteoritic analysis and elemental partition in blast furnace. There are many surprises when applied to the discussion of natural occurrences. A modified classification of ele- ments based on basic chemical properties and their occurrences. A modified classification of elements based on basic chemical properties and their occurrences in nature is, therefore, proposed for students learning geochemistry and geologists working in the field. Elements are classified into six groups including lithophile, oxyphile, siderophile, chalcophile, biophile, and at- mophile elements. Five terms are taken from Goldshcmidt’s original classification. Oxyphile is a new term.
