The rare earth elements(REE)geochemistry and the isotope(δ^(13)C,δ^(18)O)composition of manganese ores of the Chiatura(Georgia)deposit were studied.One of the major features of all types of manganese ores is negativ...The rare earth elements(REE)geochemistry and the isotope(δ^(13)C,δ^(18)O)composition of manganese ores of the Chiatura(Georgia)deposit were studied.One of the major features of all types of manganese ores is negative cerium(Ce/Ce*_(PAAS))anomaly and the absence of europium(Eu/Eu*_(PAAS))anomaly.Oxide oolitic manganese ores were formed in oxic shallow marine environments.The content and distribution of REEs(in particular Ce and Eu)in these ores are connected mainly with ferrous oxides.The performed C-and O-isotope research in Mn-carbonates(oolitic and massive)has indicated that carbonate ores were formed by the participation of isotopic ally light CO_(2)which is a result of the oxidation of organic matter in the sediment strata by reducing environments of early diagenesis(and,partially,catagenesis)zone.Obtained negative cerium anomalies in the studied carbonate ores reflect the specific REE patterns in pore waters of sediments of earlier isdiagenesis zone of the Oligocene Chiatura's basin.The deficiency of cerium in this zone remains debatable and requires further study.Formation of manganese carbonates took place multistage by the input of incisional solutions of different chemistry into sea bottom waters and sediments.The absence of europium anomaly indicates about lack of hydrothermal solution input.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The rare earth elements(REE)geochemistry and the isotope(δ^(13)C,δ^(18)O)composition of manganese ores of the Chiatura(Georgia)deposit were studied.One of the major features of all types of manganese ores is negative cerium(Ce/Ce*_(PAAS))anomaly and the absence of europium(Eu/Eu*_(PAAS))anomaly.Oxide oolitic manganese ores were formed in oxic shallow marine environments.The content and distribution of REEs(in particular Ce and Eu)in these ores are connected mainly with ferrous oxides.The performed C-and O-isotope research in Mn-carbonates(oolitic and massive)has indicated that carbonate ores were formed by the participation of isotopic ally light CO_(2)which is a result of the oxidation of organic matter in the sediment strata by reducing environments of early diagenesis(and,partially,catagenesis)zone.Obtained negative cerium anomalies in the studied carbonate ores reflect the specific REE patterns in pore waters of sediments of earlier isdiagenesis zone of the Oligocene Chiatura's basin.The deficiency of cerium in this zone remains debatable and requires further study.Formation of manganese carbonates took place multistage by the input of incisional solutions of different chemistry into sea bottom waters and sediments.The absence of europium anomaly indicates about lack of hydrothermal solution input.
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.
