In this paper the authors present the REE concentrations and Sr and Nd isotopic compositions of fluorites from the Bailashui tin deposit of the Furong ore field,southern Hunan Province. The results showed that the tot...In this paper the authors present the REE concentrations and Sr and Nd isotopic compositions of fluorites from the Bailashui tin deposit of the Furong ore field,southern Hunan Province. The results showed that the total amount of REE in fluorites is usually low,ranging from 0.705 to 8.785 μg/g with the chondrite-normalized REE dis-tribution patterns similar to those of the Qitianling granites in the study area,characterized by LREE-enrichment patterns with pronounced negative Eu anomalies. The fluorites vary in Sr isotopic composition within the range of 0.7083-0.7091,the values are lower than those of the granites and higher than those of the host carbonate rocks in this area. The εNd(t) values of fluorites vary between -9.4 and +10.3,revealing that both the crust-and mantle-source materials were involved in the ore-forming hydrothermal fluids. Combined with previous studies on this ore deposit,the Bailashui tin deposit is temporally and spatially closely related with granitic magmatism in this area. The hydro-thermal fluorites are the product of fluid/rock interactions between granitic magmatic hydrothermal fluid and marine carbonate rocks. The REE and F in the ore-forming fluid were derived from the granites,whereas Sr in the ore-forming fluid came mainly from the granitic magmatic hydrothermal fluid and marine carbonate rocks,although variations in Sr isotopic composition cannot be explained by a simple mixture of these two end-members. Evidence demonstrated that the ore-forming fluids are of crustal-mantle mixing origin,but that the fluids were probably in-completely homogenized and this may be caused by inhomogeneous mixing of the fluids of different sources.展开更多
The No. 302 uranium deposit, located in Guangdong Province, is a typical granite-type uranium ore deposit. REE geochemical characteristics of the wall rocks, pitchblende, altered rocks, calcite and fluorite from this ...The No. 302 uranium deposit, located in Guangdong Province, is a typical granite-type uranium ore deposit. REE geochemical characteristics of the wall rocks, pitchblende, altered rocks, calcite and fluorite from this deposit have been systematically studied in this paper. The result showed that the alkali-metasomatic granites and other altered rocks have the same REE distribution patterns as Indosinian granites. It is indicated that the hydrothermal ore-forming solution had altered the Indosinian granites, and ore-forming materials may directly originate from the Indosinian granites. Calcite and fluorite of different stages are the products derived from the same source but different stages. The evolution and degassing of the mineralizing solution might induce LREE enrichment to varying degree. Mantle fluid and a large volume of mineralizer may be the crucial factors controlling uranium mineralization, and the hydrothermal solution with mineralizer played an important role in U transport and concentration. Meanwhile, the degassing of CO2 might promote U and REE precipitation.展开更多
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
基金financially supported jointly by the Key Program of Knowledge Innovation from the Chinese Academy of Sciences (Grant KZCX-3-SW-125)the National Natural Science Foundation of China (Grant Nos.40472053 and 40673021)Special Foundation on Fundamental Scientific Research as Operating Expenses among Commonweal Scientific Research In-stitutes at National Level (Grant K2007-1-12)
文摘In this paper the authors present the REE concentrations and Sr and Nd isotopic compositions of fluorites from the Bailashui tin deposit of the Furong ore field,southern Hunan Province. The results showed that the total amount of REE in fluorites is usually low,ranging from 0.705 to 8.785 μg/g with the chondrite-normalized REE dis-tribution patterns similar to those of the Qitianling granites in the study area,characterized by LREE-enrichment patterns with pronounced negative Eu anomalies. The fluorites vary in Sr isotopic composition within the range of 0.7083-0.7091,the values are lower than those of the granites and higher than those of the host carbonate rocks in this area. The εNd(t) values of fluorites vary between -9.4 and +10.3,revealing that both the crust-and mantle-source materials were involved in the ore-forming hydrothermal fluids. Combined with previous studies on this ore deposit,the Bailashui tin deposit is temporally and spatially closely related with granitic magmatism in this area. The hydro-thermal fluorites are the product of fluid/rock interactions between granitic magmatic hydrothermal fluid and marine carbonate rocks. The REE and F in the ore-forming fluid were derived from the granites,whereas Sr in the ore-forming fluid came mainly from the granitic magmatic hydrothermal fluid and marine carbonate rocks,although variations in Sr isotopic composition cannot be explained by a simple mixture of these two end-members. Evidence demonstrated that the ore-forming fluids are of crustal-mantle mixing origin,but that the fluids were probably in-completely homogenized and this may be caused by inhomogeneous mixing of the fluids of different sources.
基金This work was funded jointly by the Important Research 0rientation Project under the Knowledge Innovation Program sponsored by the Chinese Academy of Sciences(Grant No.KZCX3-SW-125)the National 0utstanding Young Scientists Science Foundation of China(Grant No.49925309).
文摘The No. 302 uranium deposit, located in Guangdong Province, is a typical granite-type uranium ore deposit. REE geochemical characteristics of the wall rocks, pitchblende, altered rocks, calcite and fluorite from this deposit have been systematically studied in this paper. The result showed that the alkali-metasomatic granites and other altered rocks have the same REE distribution patterns as Indosinian granites. It is indicated that the hydrothermal ore-forming solution had altered the Indosinian granites, and ore-forming materials may directly originate from the Indosinian granites. Calcite and fluorite of different stages are the products derived from the same source but different stages. The evolution and degassing of the mineralizing solution might induce LREE enrichment to varying degree. Mantle fluid and a large volume of mineralizer may be the crucial factors controlling uranium mineralization, and the hydrothermal solution with mineralizer played an important role in U transport and concentration. Meanwhile, the degassing of CO2 might promote U and REE precipitation.
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）.
基金Supported jointly by National Basic Research Program of China (Grant Nos. 2007CB411404 and 2007CB411408)National Natural Science Foundation of China (Grant Nos. 40373020 and 40503007)"Western Light" Project of the Chinese Academy of Sciences
文摘为了调查听矿石的形成机制，与忍受 F 花岗石联系了，在忍受 F 之间的听分区的试验性的研究花岗石融化，共存的忍受 HCl 水的液体与接近 NNO 的 fo <SUB>2</SUB> 在 850 ° C 和 100MPa 被进行。锡的 Geochemical 行为被变化在以不同氧化铝浸透索引 ASI 开始稳固的材料跟踪，在 F 内容并且在开始各种各样的 HCl 集中的液体。结果显示出那 D <SUB > 有 ASI 的 Sn </SUB> 增加融化并且每铝土融化为进在 F/Cl-coexisting 系统的水的液体的听分区是有利的。更高的 HCl 集中的水的液体为锡的丰富是有益的。而且，在玻璃跑产品的氯内容在岩浆与 F 和 Cl 内容断然相关。在 F/Cl-coexisting 系统，花岗石在能为听矿石的形成用作一座水库的 melt 与内容(】∼1 wt%) 能提取并且充实的高 F 融化锡。然而，当在 melt 的 F 内容在 1 wt% 下面时，锡的分配系数将显著地增加。因此， F 内容的减少对进有高 HCl 内容的水的液体的锡的分区有利，因此支持热水的听矿石的免职。
