Chemical(REE and major elements)and isotope(δ^(13)C,δ^(18)O)composition of carbonate manganese ores and manganese-bearing carbonates of the Usa deposit(Siberia,Russia)were studied.Received data on the composition of...Chemical(REE and major elements)and isotope(δ^(13)C,δ^(18)O)composition of carbonate manganese ores and manganese-bearing carbonates of the Usa deposit(Siberia,Russia)were studied.Received data on the composition of REE exhibit both the distinct negative(Ce/Ce*_(PAAS)<1)and positive(Ce/Ce*_(PAAS)>1)cerium anomalies and the positive Eu-anomaly(Eu/Eu*_(PAAS)>1).Negative Eu-anomalies are not observed.The contents of Mn,Fe,REE,and Ce-anomalies show a positive correlation with each other.Ce-anomalies and the amount of manganese and REE in relation to the carbon isotope composition(δ^(13)C)show a negative relationship and indicate that oxidized carbon of organic matter played an important role in the concentration of manganese and REE in manganese ores.The chemical and isotope composition of examined rocks indicates on secondary formation of Mnores.Two major phases and sources are distinguished in the ore-forming process characterized by diff erent chemical(REE and ore elements)and isotope composition:(i)highgrade manganese ores(with high contents of REE and light carbon isotope composition)and(ii)low-grade manganese ores(with low contents of REE and heavy carbon isotope composition).展开更多
<正>白云鄂博稀土-铌-铁矿床位于华北地块北缘,内蒙古包头市以北150 km处,东经106~112°,北纬39~42°,地跨华北地台及内蒙海西地槽两大构造单元,台槽之间被白云鄂博北面的乌兰宝力格深大断裂所隔开,以北为内蒙海西地槽区...<正>白云鄂博稀土-铌-铁矿床位于华北地块北缘,内蒙古包头市以北150 km处,东经106~112°,北纬39~42°,地跨华北地台及内蒙海西地槽两大构造单元,台槽之间被白云鄂博北面的乌兰宝力格深大断裂所隔开,以北为内蒙海西地槽区。它是全世界最大的轻稀土矿床,其轻稀土元素储量占全球总储量的50%左右(美国地质调查局,2011),该矿床的铌储量位居世界第二,且又是一个大型的铁矿。该矿床的地质历史复杂,从地层沉积至今经历了至少11次的地质事件(Smith et al.,2000)。展开更多
REE ratios and patterns for massive pyrite ore and massive cuprous pyrite ore ofthe Baiyinchang orefield are quite similar to those for quartz keratophyritic tuff and quartzalbitophyre of the same orefield. However, m...REE ratios and patterns for massive pyrite ore and massive cuprous pyrite ore ofthe Baiyinchang orefield are quite similar to those for quartz keratophyritic tuff and quartzalbitophyre of the same orefield. However, massive cuprous pyrite ore of the Ashele Cu-Zn de-posit is similar to basalt-diabase of the same district in REE geochemistry. Comparison of theChinese VMS ores with those from Rio Tinto, Spain and Que River, Australia, in REEgeochemistry has been made. REE ratios and patterns of bedded-massive and massive ores ofthe Changba-Lijiagou Zn-Pb deposit, the second largest SEDEX deposit in China are similarto those of their host rocks, the Qinling shales of Devonian age and the Changba adamellite.The three types of ore and their host rocks of the Dongshengmiao pyrite (pyrrhotite)-Zn-Pbdeposit have parallel REE ratios and patterns.展开更多
基金accomplished in accordance with the Research Program of the Geological Institute of the Russian Academy of Sciences。
文摘Chemical(REE and major elements)and isotope(δ^(13)C,δ^(18)O)composition of carbonate manganese ores and manganese-bearing carbonates of the Usa deposit(Siberia,Russia)were studied.Received data on the composition of REE exhibit both the distinct negative(Ce/Ce*_(PAAS)<1)and positive(Ce/Ce*_(PAAS)>1)cerium anomalies and the positive Eu-anomaly(Eu/Eu*_(PAAS)>1).Negative Eu-anomalies are not observed.The contents of Mn,Fe,REE,and Ce-anomalies show a positive correlation with each other.Ce-anomalies and the amount of manganese and REE in relation to the carbon isotope composition(δ^(13)C)show a negative relationship and indicate that oxidized carbon of organic matter played an important role in the concentration of manganese and REE in manganese ores.The chemical and isotope composition of examined rocks indicates on secondary formation of Mnores.Two major phases and sources are distinguished in the ore-forming process characterized by diff erent chemical(REE and ore elements)and isotope composition:(i)highgrade manganese ores(with high contents of REE and light carbon isotope composition)and(ii)low-grade manganese ores(with low contents of REE and heavy carbon isotope composition).
文摘<正>白云鄂博稀土-铌-铁矿床位于华北地块北缘,内蒙古包头市以北150 km处,东经106~112°,北纬39~42°,地跨华北地台及内蒙海西地槽两大构造单元,台槽之间被白云鄂博北面的乌兰宝力格深大断裂所隔开,以北为内蒙海西地槽区。它是全世界最大的轻稀土矿床,其轻稀土元素储量占全球总储量的50%左右(美国地质调查局,2011),该矿床的铌储量位居世界第二,且又是一个大型的铁矿。该矿床的地质历史复杂,从地层沉积至今经历了至少11次的地质事件(Smith et al.,2000)。
基金This study was part of two projects supported by the Natural Science Foudation of China and the Joint Open Laboratory of Nuclear Analytical Techniques,Chinese Academy of Sciences,respectively.
文摘REE ratios and patterns for massive pyrite ore and massive cuprous pyrite ore ofthe Baiyinchang orefield are quite similar to those for quartz keratophyritic tuff and quartzalbitophyre of the same orefield. However, massive cuprous pyrite ore of the Ashele Cu-Zn de-posit is similar to basalt-diabase of the same district in REE geochemistry. Comparison of theChinese VMS ores with those from Rio Tinto, Spain and Que River, Australia, in REEgeochemistry has been made. REE ratios and patterns of bedded-massive and massive ores ofthe Changba-Lijiagou Zn-Pb deposit, the second largest SEDEX deposit in China are similarto those of their host rocks, the Qinling shales of Devonian age and the Changba adamellite.The three types of ore and their host rocks of the Dongshengmiao pyrite (pyrrhotite)-Zn-Pbdeposit have parallel REE ratios and patterns.
