Objective Galuskin et al. (2011) firstly discovered that vorlanite (CaU^6+/4+)04 is a rare Ca-rich mineral with a fluorite-type structure, which is isostructural with uraninite (U^4+O2). Previous studies of ...Objective Galuskin et al. (2011) firstly discovered that vorlanite (CaU^6+/4+)04 is a rare Ca-rich mineral with a fluorite-type structure, which is isostructural with uraninite (U^4+O2). Previous studies of the Xianshi granite-related uranium deposit reported that uraninite and pyrite are the major ore minerals whereas galena, clausthalite (PbSe), and pyrite are minor phases in the ores. A more detailed petrographic and geochronological study of the uranium minerals from the Xianshi deposit showed that there are three distinct types of uraninite-bearing assemblages which formed at three mineralization episodes (Fig. la; Luo et al., 2015).展开更多
The Zudong and Guanxi granites are original rocks of the ion adsorption-type HREE and LREE deposits in weathering crust of granites. The ΣREE value and LREE/HREE ratio of the Zudong granite are 264 ppm and 0.81-0.24 ...The Zudong and Guanxi granites are original rocks of the ion adsorption-type HREE and LREE deposits in weathering crust of granites. The ΣREE value and LREE/HREE ratio of the Zudong granite are 264 ppm and 0.81-0.24 respectively, and the average Y/ΣREE ratio is 35.8-54.5%. This is mainly due to magmatic crystallization and evolution and deuteric metasomatism (albitization, muscovitization and fluorite-doveritization). These alterations resulted in endogenic mineralizations of yttrium-group REE fluorine carbonates, silicates and arsenates. The Guanxi granite is characterized by LREE enrichment (the average LREE/HREE ratio is 2.43).展开更多
The evolution characteristics of Gejiu granites.Yunnan Province are described in terms of theirPetrology,especially their trace elements and REE geochemistry The three major types of Gejiu granites:porphyritic biotite...The evolution characteristics of Gejiu granites.Yunnan Province are described in terms of theirPetrology,especially their trace elements and REE geochemistry The three major types of Gejiu granites:porphyritic biotite monzonitic granite(stageⅠ),medium-coarse-grained biotite-K-feldspar granite(stage Ⅱ)and two-mica alkali-feldspar granite(stage Ⅲ)are thought to have been formed successively from the samegranite magma source through fractional crystallization(Rayliegh fractionation),because linear correlationsare found between log(Rb/Sr)-log Sn,log(Rb/Ba)-log Sn,log(Rb/Ba)-log(Rb/Sr),log La-log Sr,log Ce-log Sr,log Eu-log Sr,etc In addition.the characteristics of REE distribution patterns in these three major types ofgranites also reflect the magmatic differentiation features of Gejiu granites.Of the three major types,the twomica alkali-feldspar granite of stage Ⅲ nuderwent the strongest differentiation,and thus has the closestgenetic relationship with the Gejiu tin-polymetallic ore deposit Such tin-polymetal mineralized granites arecharacterized by high Rb/Sr and Rb/Ba ratios,low K/Rb and ∑Ce/∑Y ratios and remarkable Eu depletion.展开更多
Polymetallic nodules and crusts are two of the most important mineral deposits in the ocean. They are rich in rare earth elements (REEs), iron, manganese, copper, cobalt, nickel, and other useful metals. This paper ...Polymetallic nodules and crusts are two of the most important mineral deposits in the ocean. They are rich in rare earth elements (REEs), iron, manganese, copper, cobalt, nickel, and other useful metals. This paper discussed the analysis of 25 nodule and crust samples collected from the South China Sea, the Pacific, Atlantic, and Indian Oceans. The samples were analyzed for REE content by ICP-MS/AES. The average REE concentration was found to be 1096.96×10^-6 in the nodules and 1623.88×10^-6 in the crusts. Both of these values are much higher than those recorded in Earth's dry-land crust and sedimentary rocks. This REE enrichment is mainly controlled by the absorption of ferromanganese oxides and clay minerals in the nodules and crusts and the high levels of REEs in seawater and sediments. High cerium enrichment in the nodules and crusts may lead to more effective exploitation of REEs in the future.展开更多
基金supported by the National Key R&D Program of China (grant No. 2016YFC0600405)the Strategic Priority Research Program (B) of CAS (grant No. XDB18030202)+2 种基金the Natural Science Foundation of China (41603051)the Key Program of Science and Technology of Guizhou (grant No. [2018]1423)CSC program to Luo
文摘Objective Galuskin et al. (2011) firstly discovered that vorlanite (CaU^6+/4+)04 is a rare Ca-rich mineral with a fluorite-type structure, which is isostructural with uraninite (U^4+O2). Previous studies of the Xianshi granite-related uranium deposit reported that uraninite and pyrite are the major ore minerals whereas galena, clausthalite (PbSe), and pyrite are minor phases in the ores. A more detailed petrographic and geochronological study of the uranium minerals from the Xianshi deposit showed that there are three distinct types of uraninite-bearing assemblages which formed at three mineralization episodes (Fig. la; Luo et al., 2015).
文摘The Zudong and Guanxi granites are original rocks of the ion adsorption-type HREE and LREE deposits in weathering crust of granites. The ΣREE value and LREE/HREE ratio of the Zudong granite are 264 ppm and 0.81-0.24 respectively, and the average Y/ΣREE ratio is 35.8-54.5%. This is mainly due to magmatic crystallization and evolution and deuteric metasomatism (albitization, muscovitization and fluorite-doveritization). These alterations resulted in endogenic mineralizations of yttrium-group REE fluorine carbonates, silicates and arsenates. The Guanxi granite is characterized by LREE enrichment (the average LREE/HREE ratio is 2.43).
文摘The evolution characteristics of Gejiu granites.Yunnan Province are described in terms of theirPetrology,especially their trace elements and REE geochemistry The three major types of Gejiu granites:porphyritic biotite monzonitic granite(stageⅠ),medium-coarse-grained biotite-K-feldspar granite(stage Ⅱ)and two-mica alkali-feldspar granite(stage Ⅲ)are thought to have been formed successively from the samegranite magma source through fractional crystallization(Rayliegh fractionation),because linear correlationsare found between log(Rb/Sr)-log Sn,log(Rb/Ba)-log Sn,log(Rb/Ba)-log(Rb/Sr),log La-log Sr,log Ce-log Sr,log Eu-log Sr,etc In addition.the characteristics of REE distribution patterns in these three major types ofgranites also reflect the magmatic differentiation features of Gejiu granites.Of the three major types,the twomica alkali-feldspar granite of stage Ⅲ nuderwent the strongest differentiation,and thus has the closestgenetic relationship with the Gejiu tin-polymetallic ore deposit Such tin-polymetal mineralized granites arecharacterized by high Rb/Sr and Rb/Ba ratios,low K/Rb and ∑Ce/∑Y ratios and remarkable Eu depletion.
基金National Natural Science Foundation of China(40972079,41172015 and 41030853)the State Key Research Develop-ment Program of China(2007CB411703)+1 种基金the Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology,Ministry of Landand Resources(MRE200912)the Fund of Education Department of Hebei Province(2009443,2010148)
文摘Polymetallic nodules and crusts are two of the most important mineral deposits in the ocean. They are rich in rare earth elements (REEs), iron, manganese, copper, cobalt, nickel, and other useful metals. This paper discussed the analysis of 25 nodule and crust samples collected from the South China Sea, the Pacific, Atlantic, and Indian Oceans. The samples were analyzed for REE content by ICP-MS/AES. The average REE concentration was found to be 1096.96×10^-6 in the nodules and 1623.88×10^-6 in the crusts. Both of these values are much higher than those recorded in Earth's dry-land crust and sedimentary rocks. This REE enrichment is mainly controlled by the absorption of ferromanganese oxides and clay minerals in the nodules and crusts and the high levels of REEs in seawater and sediments. High cerium enrichment in the nodules and crusts may lead to more effective exploitation of REEs in the future.