Geochemical Characteristics of Sedimentary Manganese Deposit of Guichi, Anhui Province, China  

作　　者：谢建成 杨晓勇 杜建国 许卫 

机构地区：[1]CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China [2]Anhui Academy of Geological Survey, Hefei 230001, China

出　　处：《Journal of Rare Earths》2006年第3期374-380,共7页稀土学报（英文版）

基　　金：ProjectsupportedbytheNationalBasicResearchProgramofChina(2003CB214600)andProspectingProjectofAnhuiBureauofLandandResources

摘　　要：The sedimentary manganese deposits occurring in Gufeng formation of the Permian in Guichi area, south Anhui Province, include manganese carbonate deposit formed by sedimentation, and manganese oxide deposit made by later oxidation. The total REE contents of these samples are relatively low （ 〈 250 × 10^- 6）, belonging to LREE-enriched type, showing LREE enrichment during the process of formation of Mn deposit, especially during Mn-oxidizing process. Three normalized REE patterns and SCNA-normalized trace elements spider diagrams of the Mn-bearing sequence rocks and ores in this area reflect their same origin of ore sources, which is similar to rock-forming and ore-forming conditions. The Mnforming materials primarily came from the continent with higher mature degree and single material source. The δEu and δCe negative anomaly and Ce anomaly （ 〈 - 0.1） manifest that Mn-bearing sequence of the Permian was mostly formed in marine basin and oxidative environment. The Sr and Ba anomaly, Sr/Ba and Co/Ni values reflect the Mn deposit environment was of deep water and high-salinity of marine facies. Although the Ce/La （mean 1.05）, Y/Ho （25 - 41.5） and trace metals show a variety of correlations with Mn in the ten rock samples, which show multiple sources for the manganese, the analysis of geochemical characteristics indicate that the material sources of Mn deposit have been primarily terrestriallyderived. Another source of the manganese probably comes from the seafloor volcanism in this area. Analysis of sedimentary features and geohistoric evolvement reveals that the maximum transgression of the Qixia Period, ore district is then in deep shelf-basin sedimentary setting and the Mn-bearing sequence is deposited.The sedimentary manganese deposits occurring in Gufeng formation of the Permian in Guichi area, south Anhui Province, include manganese carbonate deposit formed by sedimentation, and manganese oxide deposit made by later oxidation. The total REE contents of these samples are relatively low （ 〈 250 × 10^- 6）, belonging to LREE-enriched type, showing LREE enrichment during the process of formation of Mn deposit, especially during Mn-oxidizing process. Three normalized REE patterns and SCNA-normalized trace elements spider diagrams of the Mn-bearing sequence rocks and ores in this area reflect their same origin of ore sources, which is similar to rock-forming and ore-forming conditions. The Mnforming materials primarily came from the continent with higher mature degree and single material source. The δEu and δCe negative anomaly and Ce anomaly （ 〈 - 0.1） manifest that Mn-bearing sequence of the Permian was mostly formed in marine basin and oxidative environment. The Sr and Ba anomaly, Sr/Ba and Co/Ni values reflect the Mn deposit environment was of deep water and high-salinity of marine facies. Although the Ce/La （mean 1.05）, Y/Ho （25 - 41.5） and trace metals show a variety of correlations with Mn in the ten rock samples, which show multiple sources for the manganese, the analysis of geochemical characteristics indicate that the material sources of Mn deposit have been primarily terrestriallyderived. Another source of the manganese probably comes from the seafloor volcanism in this area. Analysis of sedimentary features and geohistoric evolvement reveals that the maximum transgression of the Qixia Period, ore district is then in deep shelf-basin sedimentary setting and the Mn-bearing sequence is deposited.

关 键 词：manganese ore trace elements GEOCHEMISTRY Guichi area Anhui Province rare earths 

分 类 号：P618.32[天文地球—矿床学] P595[天文地球—地质学]