A combination of the high temperature CO2-H2O equilibrium method and hot uranium or zinc method has been established for simultaneous determination of oxygen and hydrogen isotopes extracted from microlitre order of wa...A combination of the high temperature CO2-H2O equilibrium method and hot uranium or zinc method has been established for simultaneous determination of oxygen and hydrogen isotopes extracted from microlitre order of water samples. The analytical accuracy of this method is±0.1‰ for oxygen and±1.0‰ for hydrogen. As an additional merit of this instrument it is easy to operate and only 3 hours are needed to complete a run. Preliminary results of its application to determining isotopic composition of fluid inclusion are satisfactory.展开更多
The Xizang Plateau, with a common altitude of more than 4000 m sbove sea level,has long been celebrated as “The Roof of the World”. In order to study oxygen isotopic composition of meteoric water in the Xizang Plate...The Xizang Plateau, with a common altitude of more than 4000 m sbove sea level,has long been celebrated as “The Roof of the World”. In order to study oxygen isotopic composition of meteoric water in the Xizang Plateau Region and its relationship with the attitude, we made an investigation tour to the Xizang Plateau, starting from Guizhow, during 1979 from July to October, and 79 meteoric Water samples were collected, including brook, well, lake, snow, firn, spring and running waters, at different altitudes. Oxygen isotope analyses indicate that the isotopie composition of meteoric water in the areas more than 4000g and in the western parts of SichuanGaizhow shows remarkable altitude effect. There is a negative correlation between δ^28O and altitude, which is reflected by --δ^18O = 0.0026H+7.75. The average δ^18O value for metcoric water in the areas: more than 4000m above sea level turns out to be --18.15‰ is evident that δ^18O value for lake water on the plateau is related to its water supply. δ^18O value for lake water, in which the evaporation is greater than supply,is approximately three or four times higher than that of supplied water, averaging -5.74‰. Oxygen isotopic compasition of geothermal water can be compared with that of local meteoric water, but shows certain δ^18O-shift, suggesting that the main water-supply source seems to be meteoric water in the same area.展开更多
We first established a method utilizing the oxygen isotope equilibration between water vapor and CO<sub>2</sub> gas catalyzed by a hot platinum filament at 1300°C for analysing oxygen isotope composit...We first established a method utilizing the oxygen isotope equilibration between water vapor and CO<sub>2</sub> gas catalyzed by a hot platinum filament at 1300°C for analysing oxygen isotope composition in China in 1982. It is especially suitable for simultaneously analysing H-O isotope composition of microliter water extracted from fluid inclusion according to our exoerience. The minimum ouantitv of water for this method is 2 μl. The water contents展开更多
Oxygen and carbon isotopic compositions of diagenesis?coral samples from NY 1 core at the depth of 22 to 50 m, together with mineral compositions of transitive coral samples of 17 to 18 m at the depth, were meas ured....Oxygen and carbon isotopic compositions of diagenesis?coral samples from NY 1 core at the depth of 22 to 50 m, together with mineral compositions of transitive coral samples of 17 to 18 m at the depth, were meas ured. The data exhibited that when aragonite changed to calcite, its oxygen and carbon isotopic compositions dropped roughly on a linear trend. The linear trend implies that the oscillation pattern of the origin oxygen and carbon isotopic ratios of the aragonite could probably be retained after they diageneticly changed into calcite. Oxygen isotopic stratigraphy for the NY 1 core at the depth between 22 and 50 m was determined according to the δ 18 O ratios of the calcite coral. The oxygen stratigraphy provided an age of about 289 ka for 45 m of the NY 1 core, which agreed with that by paleomagnetic stratigraphy.展开更多
The O-C isotope compositions of reef-facies carbonates of NY-1 (Nanyong-1) core in Nansha area can be divided into 4 stages. The average values of δ18O (‰) and δ13C (‰) for the 4 stages are (I) -5.0, -0.5; (11) -7...The O-C isotope compositions of reef-facies carbonates of NY-1 (Nanyong-1) core in Nansha area can be divided into 4 stages. The average values of δ18O (‰) and δ13C (‰) for the 4 stages are (I) -5.0, -0.5; (11) -7.7, -5.3; (III) -6.4, -2.8; (IV) 1.3, 2.1, respectively. The characters of δ18O fluctuating curves of stage II are low frequencies, small amplitudes and corresponding correlation with glacial and mterglacial stages. It has positive correlations between δ18O and δ13C values in stages III and IV, which are genetically related to dolomitization. The characteristics of 4 stages also exist in Δ87Sr and in Pb isotope compositions The maximun. minimum and all the positive values of Δ87Sr in the core of the whole hole occur in stage 11 The characters of frequently changing fluctuation appear in stage IV for both Pb and Sr isotope compositions The lead with high μ values was taken in during dolomitization. The history of palaeoclimatic and palaeoenvironmental changes in Nansha region during the Quaternary period was recorded in the O, C, Sr, Pb isotope compositions of reef-facies carbonate.展开更多
The correlation between δD and H_2O content in granitoid can be divided into threetypes: closed-system crystallization type (Darongshan type): a flat positive linear corre-lation; open-system degassing type (Laoshan ...The correlation between δD and H_2O content in granitoid can be divided into threetypes: closed-system crystallization type (Darongshan type): a flat positive linear corre-lation; open-system degassing type (Laoshan type): a nearly vertical linear positive cor-relation; meteoric hydrothermal exchange type (Gabug type): an irregular negative trendcorrelation.展开更多
文摘A combination of the high temperature CO2-H2O equilibrium method and hot uranium or zinc method has been established for simultaneous determination of oxygen and hydrogen isotopes extracted from microlitre order of water samples. The analytical accuracy of this method is±0.1‰ for oxygen and±1.0‰ for hydrogen. As an additional merit of this instrument it is easy to operate and only 3 hours are needed to complete a run. Preliminary results of its application to determining isotopic composition of fluid inclusion are satisfactory.
文摘The Xizang Plateau, with a common altitude of more than 4000 m sbove sea level,has long been celebrated as “The Roof of the World”. In order to study oxygen isotopic composition of meteoric water in the Xizang Plateau Region and its relationship with the attitude, we made an investigation tour to the Xizang Plateau, starting from Guizhow, during 1979 from July to October, and 79 meteoric Water samples were collected, including brook, well, lake, snow, firn, spring and running waters, at different altitudes. Oxygen isotope analyses indicate that the isotopie composition of meteoric water in the areas more than 4000g and in the western parts of SichuanGaizhow shows remarkable altitude effect. There is a negative correlation between δ^28O and altitude, which is reflected by --δ^18O = 0.0026H+7.75. The average δ^18O value for metcoric water in the areas: more than 4000m above sea level turns out to be --18.15‰ is evident that δ^18O value for lake water on the plateau is related to its water supply. δ^18O value for lake water, in which the evaporation is greater than supply,is approximately three or four times higher than that of supplied water, averaging -5.74‰. Oxygen isotopic compasition of geothermal water can be compared with that of local meteoric water, but shows certain δ^18O-shift, suggesting that the main water-supply source seems to be meteoric water in the same area.
文摘We first established a method utilizing the oxygen isotope equilibration between water vapor and CO<sub>2</sub> gas catalyzed by a hot platinum filament at 1300°C for analysing oxygen isotope composition in China in 1982. It is especially suitable for simultaneously analysing H-O isotope composition of microliter water extracted from fluid inclusion according to our exoerience. The minimum ouantitv of water for this method is 2 μl. The water contents
文摘Oxygen and carbon isotopic compositions of diagenesis?coral samples from NY 1 core at the depth of 22 to 50 m, together with mineral compositions of transitive coral samples of 17 to 18 m at the depth, were meas ured. The data exhibited that when aragonite changed to calcite, its oxygen and carbon isotopic compositions dropped roughly on a linear trend. The linear trend implies that the oscillation pattern of the origin oxygen and carbon isotopic ratios of the aragonite could probably be retained after they diageneticly changed into calcite. Oxygen isotopic stratigraphy for the NY 1 core at the depth between 22 and 50 m was determined according to the δ 18 O ratios of the calcite coral. The oxygen stratigraphy provided an age of about 289 ka for 45 m of the NY 1 core, which agreed with that by paleomagnetic stratigraphy.
基金Report D-00044 of The Multidisciplinary Oceanographic Expedition Team of Chinese Academy of Sciences to tbe Nansha Archipelago. Part of funds was supported by the National Natural Science Foundation of China.
文摘The O-C isotope compositions of reef-facies carbonates of NY-1 (Nanyong-1) core in Nansha area can be divided into 4 stages. The average values of δ18O (‰) and δ13C (‰) for the 4 stages are (I) -5.0, -0.5; (11) -7.7, -5.3; (III) -6.4, -2.8; (IV) 1.3, 2.1, respectively. The characters of δ18O fluctuating curves of stage II are low frequencies, small amplitudes and corresponding correlation with glacial and mterglacial stages. It has positive correlations between δ18O and δ13C values in stages III and IV, which are genetically related to dolomitization. The characteristics of 4 stages also exist in Δ87Sr and in Pb isotope compositions The maximun. minimum and all the positive values of Δ87Sr in the core of the whole hole occur in stage 11 The characters of frequently changing fluctuation appear in stage IV for both Pb and Sr isotope compositions The lead with high μ values was taken in during dolomitization. The history of palaeoclimatic and palaeoenvironmental changes in Nansha region during the Quaternary period was recorded in the O, C, Sr, Pb isotope compositions of reef-facies carbonate.
基金Project supported by National Natural Science Foundation of China.
文摘The correlation between δD and H_2O content in granitoid can be divided into threetypes: closed-system crystallization type (Darongshan type): a flat positive linear corre-lation; open-system degassing type (Laoshan type): a nearly vertical linear positive cor-relation; meteoric hydrothermal exchange type (Gabug type): an irregular negative trendcorrelation.
