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岩石学报 2000
Sulfides in mantle xenoliths of Cenozoic basalts from Liuhe, Jiangsu province, China.
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Abstract:
Mantle xenoliths captured in alkali basalt occurs widely in the Liuhe district, Jiangsu province, China, dominantly by spinel lherzolite. Sulfides are commonly found in minerals of the mantle xenoliths. They occur as: (1) early sulfide grains captured by host minerals; (2) intergranular or filling in the fissures; and (3) sulfide melt inclusions, including one phase sulfide inclusions, sulfide glass two phase melt inclusions, and CO 2 sulfide glass (sometimes containing silicate daughter minerals) poly phase melt inclusions. Electron microprobe analysis shows that sulfide melt inclusions have higher Fe and S contents and lower Ni content than sulfides in fissures do. The molar ratios of Ni to Fe, r Ni / r Fe , of sulfide melt inclusions range from 0.14 to 1.73, generally from 0.70 to 1.55, while those of intergranular sulfides range from 1.76 to 7.03 . Like that of Liuhe, sulfide melt inclusions in Hannuoba (Hebei province), Xinchang (Zhejiang province) and Qilin (Guangdong province) have higher Fe and S contents and lower Ni content when compared to intergranular sulfides. For both sulfide melt inclusions and intergranular sulfides, S contents increase from Liuhe, Xinchang, and Hannuoba to Qilin, Fe contents increase from Liuhe, Xinchang, Qilin, to Hannuoba; while Ni( Co) contents decrease from Liuhe, Xinchang, Qilin, to Hannuoba. It is indicated that there is a close relationship between intergranular sulfides and sulfide melt inclusions.