The silver contents of organic matter in the host rocks of the Songxishale-hosted Ag-Sb deposit of northeastern Guangdong, South China, have been directly determinedusing the electron microprobe technique. The silver ...The silver contents of organic matter in the host rocks of the Songxishale-hosted Ag-Sb deposit of northeastern Guangdong, South China, have been directly determinedusing the electron microprobe technique. The silver contents in two types of organic matter, marinevitrinite and solid bitumen, vary in the range from 100 X 10^(-6) to 350 X 10^(-6), which are fromtens of times to thousands of times higher than those of the host rocks in the ore deposit. Theaverage silver content of the organic matter is also several times higher than the pay grade ofsilver for commercial mining of the ore deposit. It is quite obvious that the organic matter of thehost rocks in the ore district is characterized by an anomalous enrichment of silver. The results ofthis study indicate that the silver anomalies in the organic matter have been derived from both thehost rocks and the silver-bearing fluids of the Songxi black shale ore source. In the course ofsedimentation and later hydrothermal reworking, organic matter was able to entrap the element silverfrom source rocks and silver-bearing fluids through complexation and reduction, so that silvercould be further enriched (or precipitated) in the solid bitumen. The quantitative assessment inthis study suggests that the distribution of solid bitumens in the ore district may be considered anindication for mineral exploration.展开更多
基金the National Natural Science Foundation of China(Grant 49872037)the State Education Ministry Foundation for excellent young teachers the Youth Science Foundation of Jiangsu Province(Grant BQ96007)
文摘The silver contents of organic matter in the host rocks of the Songxishale-hosted Ag-Sb deposit of northeastern Guangdong, South China, have been directly determinedusing the electron microprobe technique. The silver contents in two types of organic matter, marinevitrinite and solid bitumen, vary in the range from 100 X 10^(-6) to 350 X 10^(-6), which are fromtens of times to thousands of times higher than those of the host rocks in the ore deposit. Theaverage silver content of the organic matter is also several times higher than the pay grade ofsilver for commercial mining of the ore deposit. It is quite obvious that the organic matter of thehost rocks in the ore district is characterized by an anomalous enrichment of silver. The results ofthis study indicate that the silver anomalies in the organic matter have been derived from both thehost rocks and the silver-bearing fluids of the Songxi black shale ore source. In the course ofsedimentation and later hydrothermal reworking, organic matter was able to entrap the element silverfrom source rocks and silver-bearing fluids through complexation and reduction, so that silvercould be further enriched (or precipitated) in the solid bitumen. The quantitative assessment inthis study suggests that the distribution of solid bitumens in the ore district may be considered anindication for mineral exploration.
