Sulphur and Lead Isotope Compositions of the Dajiangping Deposit in Western Guangdong Province

The Dajiangping pyrite deposit located in the middle sector of the Yunkai uplift in western Guangdong is a stratiform sulphide deposit occurring in Sinian marine clastic and fine clastic rocks. The formation of the deposit was related to submarine exhalation and hot brine deposition. A part of it was reformed by late-stage hydrothermal solution. The δ34S values of pyrite vary from - 25.55‰ to +21.07‰, which are inversely proportional to the content of organic carbon in ore and pyrite. Passing from striped fine-grained pyrite ore to massive coarse-grained pyrite ore, i.e. from south to north, the sulphur isotopic composition changes from the light sulphur-enriched one to the heavy sulphur-enriched one. The lead isotopic composition of striped ore is consistent with that of the country rocks of orebodies and the lead is radiogenic lead derived from the upper crust. The lead isotopic composition of massive ore is relatively homogeneous and its 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios are a bit lower than those of striped ore;the lead result from mixing of synsedimentary ore lead with that derived from basement migmatlte brought by late-stage hydrothermal solutions.

Spatial Variation and Sources of Atmospheric Sulfur Deposition in Nanchang

[Objective] The paper aimed to discuss the relationship between sulfur contents of mosses and the concentration of SO2-4 and the source of Atmospheric sulfur in Nanchang.[Method] 29 moss samples （Bryohaplocladium micriophyllum （Hedw.） R.Watanabe et Iwats） were collected from four sampling points,including North campus and Qianhu campus of Nanchang Power Station were determined.[Result] The results showed that sulfur contents of mosses tissues in North campus of Nanchang University （0.45±0.059%） were higher than Qianhu campus of Nanchang University （0.26±0.002%）,which coincided with the changing law of the concentration of SO2-4.Sulphur isotope of mosses tissues was-0.64‰-9.71‰.Sulphur isotope of mosses tissues in Meling （4.02‰-9.71‰） was higher than Qianhu campus of Nanchang University （0.55‰-0.56‰） and power plant （-0.64‰-0.45‰）.[Conclusion] Relationship between sulphur contents and sulphur isotopes of mosses tissues showed sulfur source of sulphur deposition in Nanchang city was mainly affected by 34S-enriched sulphur transported from northerly air masses and biogenic sulfur.