The issues of acid mine drainage （AMD） and heavy metals contamination in the metal sulfide mine in the add district were explored, through studying the acidification and the heavy metals distribution and evolution o...The issues of acid mine drainage （AMD） and heavy metals contamination in the metal sulfide mine in the add district were explored, through studying the acidification and the heavy metals distribution and evolution of groundwater in the black swan （BS） nickel sulfide mine （Western Australia）. The groundwater samples were collected from the drilling holes situated in the vicinity of tailings storage facility （TSF） and in the background of the mine （away from TSF）, respectively, and the pH and electric conductivity （Ec） were measured in site and the metal contents were analysed by ICP-MS and ICP-AES, quarterly in one hydrological year. The results disclose that the TSF groundwater is remarkably acidified （.pHmean=5, pHmin=3）, and the average contents of heavy metals （Co, Cu, Zn, Cd） and Al, Mn are of 1-2 orders of magnitude higher in TSF groundwater than in background groundwater. It may be due to the percolation of tailings waste water from miU process, which leads the tailings to oxidize and the deep groundwater to acidify and contaminate with heavy metals. Besides, the heavy metals concentration in groundwater may be controlled by pH mainly.展开更多
Meteorites are the extraterrestrial rocks, which provide insights into the origin and evolution of the solar system. During the past half century, a great number of meteorites has been discovered on the Antarctic Ice ...Meteorites are the extraterrestrial rocks, which provide insights into the origin and evolution of the solar system. During the past half century, a great number of meteorites has been discovered on the Antarctic Ice Sheet, confirming that the Antarctica is the most important meteorite concentration area on the earth. Since the first four Antarctic meteorites were found in Grove Mountains in 1998, a total of 9834 meteorites have been collected by four subsequent expeditions. It opens a new field of meteorite study in China, and also accumulates a great deal of scientific samples for China. Recently, classification of Grove Mountains meteorites has been carried out for 6 years, and made following progresses ： （ 1 ） 2433 meteorites, which include many special meteorites, e.g. Martian meteorites, ureilites and carbonaceous chondrites, have been classified. （2） the Antarctic meteorite curation and the sample sharing system are set up preliminarily. （3） the classification procedure, the management of meteorite samples, and the application procedure for the Antarctic meteorites are completed after the systematic classification during these years. （4） young generation researchers on meteorite are trained through the cooperation of many universities and institutes on meteorite classification.展开更多
Ureilites are a common group of achondrites with a high abundance of carbon. They probably have a genetic relationship with chondrites, hence provide an insight into origin and evdution of terrestrial planets. A new m...Ureilites are a common group of achondrites with a high abundance of carbon. They probably have a genetic relationship with chondrites, hence provide an insight into origin and evdution of terrestrial planets. A new meteorite-rich region, Grove Mountains （ GRV）, was found by the Chinese Antarctic Research Expedition, with discovery of 9834 meteorites. Of 2433 meteorites classified, 9 ureilites have been identified. In this paper, we report petrography of 6 of these ureilites. Four ureilites contain graphite and exhibit triangle conjunction and common reduced margins of divine. GRV 052382 probably experienced heavy shock metamorphism followed by fast coding, as indicated by mosaic texture or fine-grained granular texture of olivine. GRV 022931 was highly reduced of these ureilites, with olivine as isolated grains in abundant carbonaceous matrix. All 9 ureilites are monomict, and arc classified into subtype II （with medium FeO content, Fa15-18 ） and subtype I （with high FeO content, Fa 〉 18） based on compositions of the cores of olivine. The diverse mineral compositions and petrography of these ureilites suggest that they are not paired and reveal a multi-event history of the parent body. Partial melting of the parent body produced carbon-rich magma, followed by crystallization of graphite and silicates. Later, graphite was partially inverted to diamond by shock events. Reburial of the shocked debris experienced various degree of thermal metamorphism. Finally, these rocks were excavated from the parent asteroid and ejected into Earth-cross orbit by another impact event.展开更多
The shock metamorphism of 47 H group chondrites （H-chondrites） from the Grove Mountains including undulatory extinction, planar fractures, mosaic extinction, shock veins and pockets, and dendritic eutectic metal-sul...The shock metamorphism of 47 H group chondrites （H-chondrites） from the Grove Mountains including undulatory extinction, planar fractures, mosaic extinction, shock veins and pockets, and dendritic eutectic metal-sulfide, is observed through optical microscope. The textures and assemblages of shock veins in these H-chondrites are examined by the scanning electron microscope. Based on observations of the above shock effects, the shock stages of the 47 H-chondrites are classified into S1（5）, S2（19）,S$3（14）, S4（8） and S5（1）. Of these H-chondrites, GRV 022469 has the highest（S5） shock stage. The comparison of shock stages in these H-chondrites with L group chondrites（L-chondrites） indicates that the shock metamorphism of H-chondrites is relatively low （except for GRV 022469, they are all lower than $5）. A scenario for the history of the H-chondrite parent body is proposed that suggests the duration of the shock events in the H-chondrite parent bodies was much shorter than those in L-chondrite parent bodies. Also, the pressure may have been released more quickly, and consequently, the high-pressure phases should be easily preserved. However, the parent bodies of the H-chondrites may have been exposed to high temperatures for a longer time after the shock event, so the high-pressure phases formed by solid transformation might have retro-metamorphosed to low-pressure ones; its peak pressure is estimated to be less than 15 GPa. Wadsleyite was found in a shock vein in GRV022469, as confirmed by the Raman spectrometer. Petrological and mineralogical characteristics support the idea that the wadsleyite was formed by solid-state transformation.展开更多
AMD(Acid Mine Drainage)-type acidic groundwater (pH<4) from oxidizing sulfide tailings in BS nickel mine (Western Australia) is of higher total rare earth element(REE) contents and Ce enrichment (PAAS normalization...AMD(Acid Mine Drainage)-type acidic groundwater (pH<4) from oxidizing sulfide tailings in BS nickel mine (Western Australia) is of higher total rare earth element(REE) contents and Ce enrichment (PAAS normalization), different from setting groundwater (pH>6.5, with lower total REE contents, Ce depletion). While the AMD contaminated groundwater (pH=4.0-6.5) around tailings pond is characterized by transition from acidic to setting groundwater in total REE content, and associated with Ce depletion (like setting groundwater). The light REE in all type groundwater shows up depletion, but its depleted extent in acidic groundwater is more remarkable. This work indicates that REE behavior in AMD-type acidic groundwater is controlled mainly by pH value and metal (Al, Mn and Fe) contents. And the critical pH value that affects REE behavior in ground acidic water would be 4, lower than the previous value (pH=5) that has been believed prevalently in surface acidic waters. The pH could affect REE behavior in groundwater by controlling the solubility of metal (Al, Mn and Fe) hydroxides and the valence of cerium. Finally, light REE depletion in acidic groundwater may due to element affinity. High content Al (affinity with heavy REE) and low content Fe (affinity with light REE) may lead to heavy REE enrichment while light REE relative depletion in water.展开更多
基金Projects(40972220,40873030) supported by the National Natural Science Foundation of ChinaProject(0991024) supported by the Special Project for Applied Basic Research of Guangxi,China
文摘The issues of acid mine drainage （AMD） and heavy metals contamination in the metal sulfide mine in the add district were explored, through studying the acidification and the heavy metals distribution and evolution of groundwater in the black swan （BS） nickel sulfide mine （Western Australia）. The groundwater samples were collected from the drilling holes situated in the vicinity of tailings storage facility （TSF） and in the background of the mine （away from TSF）, respectively, and the pH and electric conductivity （Ec） were measured in site and the metal contents were analysed by ICP-MS and ICP-AES, quarterly in one hydrological year. The results disclose that the TSF groundwater is remarkably acidified （.pHmean=5, pHmin=3）, and the average contents of heavy metals （Co, Cu, Zn, Cd） and Al, Mn are of 1-2 orders of magnitude higher in TSF groundwater than in background groundwater. It may be due to the percolation of tailings waste water from miU process, which leads the tailings to oxidize and the deep groundwater to acidify and contaminate with heavy metals. Besides, the heavy metals concentration in groundwater may be controlled by pH mainly.
基金funded by the National Natural Science Foundation of China(Grant No.40473037 and 40673055)Guangxi College Talents Support Program(RC2007020)
文摘Meteorites are the extraterrestrial rocks, which provide insights into the origin and evolution of the solar system. During the past half century, a great number of meteorites has been discovered on the Antarctic Ice Sheet, confirming that the Antarctica is the most important meteorite concentration area on the earth. Since the first four Antarctic meteorites were found in Grove Mountains in 1998, a total of 9834 meteorites have been collected by four subsequent expeditions. It opens a new field of meteorite study in China, and also accumulates a great deal of scientific samples for China. Recently, classification of Grove Mountains meteorites has been carried out for 6 years, and made following progresses ： （ 1 ） 2433 meteorites, which include many special meteorites, e.g. Martian meteorites, ureilites and carbonaceous chondrites, have been classified. （2） the Antarctic meteorite curation and the sample sharing system are set up preliminarily. （3） the classification procedure, the management of meteorite samples, and the application procedure for the Antarctic meteorites are completed after the systematic classification during these years. （4） young generation researchers on meteorite are trained through the cooperation of many universities and institutes on meteorite classification.
基金supported by the National Natural Science Foundation of China(No.40473037 and 40673055)Guangxi College Talents Support Program(RC2007020)
文摘Ureilites are a common group of achondrites with a high abundance of carbon. They probably have a genetic relationship with chondrites, hence provide an insight into origin and evdution of terrestrial planets. A new meteorite-rich region, Grove Mountains （ GRV）, was found by the Chinese Antarctic Research Expedition, with discovery of 9834 meteorites. Of 2433 meteorites classified, 9 ureilites have been identified. In this paper, we report petrography of 6 of these ureilites. Four ureilites contain graphite and exhibit triangle conjunction and common reduced margins of divine. GRV 052382 probably experienced heavy shock metamorphism followed by fast coding, as indicated by mosaic texture or fine-grained granular texture of olivine. GRV 022931 was highly reduced of these ureilites, with olivine as isolated grains in abundant carbonaceous matrix. All 9 ureilites are monomict, and arc classified into subtype II （with medium FeO content, Fa15-18 ） and subtype I （with high FeO content, Fa 〉 18） based on compositions of the cores of olivine. The diverse mineral compositions and petrography of these ureilites suggest that they are not paired and reveal a multi-event history of the parent body. Partial melting of the parent body produced carbon-rich magma, followed by crystallization of graphite and silicates. Later, graphite was partially inverted to diamond by shock events. Reburial of the shocked debris experienced various degree of thermal metamorphism. Finally, these rocks were excavated from the parent asteroid and ejected into Earth-cross orbit by another impact event.
基金supported by the Pilot Project of Knowledge Innovation of Chinese Academy of Sciences (Grant no.KZCX2-YW-110)the National Natural Science Foundation of China(Grant nos. 40673055 and 40473037)the Open Foundation of Key Laboratory of Geological Engineering Centre of Guangxi Province (Grantno. Gui Ke Neng 07109011-K024)
文摘The shock metamorphism of 47 H group chondrites （H-chondrites） from the Grove Mountains including undulatory extinction, planar fractures, mosaic extinction, shock veins and pockets, and dendritic eutectic metal-sulfide, is observed through optical microscope. The textures and assemblages of shock veins in these H-chondrites are examined by the scanning electron microscope. Based on observations of the above shock effects, the shock stages of the 47 H-chondrites are classified into S1（5）, S2（19）,S$3（14）, S4（8） and S5（1）. Of these H-chondrites, GRV 022469 has the highest（S5） shock stage. The comparison of shock stages in these H-chondrites with L group chondrites（L-chondrites） indicates that the shock metamorphism of H-chondrites is relatively low （except for GRV 022469, they are all lower than $5）. A scenario for the history of the H-chondrite parent body is proposed that suggests the duration of the shock events in the H-chondrite parent bodies was much shorter than those in L-chondrite parent bodies. Also, the pressure may have been released more quickly, and consequently, the high-pressure phases should be easily preserved. However, the parent bodies of the H-chondrites may have been exposed to high temperatures for a longer time after the shock event, so the high-pressure phases formed by solid transformation might have retro-metamorphosed to low-pressure ones; its peak pressure is estimated to be less than 15 GPa. Wadsleyite was found in a shock vein in GRV022469, as confirmed by the Raman spectrometer. Petrological and mineralogical characteristics support the idea that the wadsleyite was formed by solid-state transformation.
基金Project supported by the Science Foundation of Guangxi Province, ChinaProject supported by the Director Fund Project of Key Laboratory of Geological Engineering Center of Guangxi Province, China
文摘AMD(Acid Mine Drainage)-type acidic groundwater (pH<4) from oxidizing sulfide tailings in BS nickel mine (Western Australia) is of higher total rare earth element(REE) contents and Ce enrichment (PAAS normalization), different from setting groundwater (pH>6.5, with lower total REE contents, Ce depletion). While the AMD contaminated groundwater (pH=4.0-6.5) around tailings pond is characterized by transition from acidic to setting groundwater in total REE content, and associated with Ce depletion (like setting groundwater). The light REE in all type groundwater shows up depletion, but its depleted extent in acidic groundwater is more remarkable. This work indicates that REE behavior in AMD-type acidic groundwater is controlled mainly by pH value and metal (Al, Mn and Fe) contents. And the critical pH value that affects REE behavior in ground acidic water would be 4, lower than the previous value (pH=5) that has been believed prevalently in surface acidic waters. The pH could affect REE behavior in groundwater by controlling the solubility of metal (Al, Mn and Fe) hydroxides and the valence of cerium. Finally, light REE depletion in acidic groundwater may due to element affinity. High content Al (affinity with heavy REE) and low content Fe (affinity with light REE) may lead to heavy REE enrichment while light REE relative depletion in water.
