中国东部地幔岩中硫化物包裹体特征及区域对比

Sulfides in mantle xenoliths are usually found in East China. They occur as isolated grains, fluid-melt inclusions and fillings in fractures. The mineral contents of these sulfides are various minerals in the system of Fe-Ni-Cu-S, including MSS with different ratios of Ni/Fe, pyrrotite, pentlandite and chalcopyrite. From isolated grains, sulfide inclusions to filling minerals, minerals vary from pyrrotite, MSS to pentlandite. The main components in mantles sulfides (S, Fe, Ni and Cu) are changeble in different areas. From Hainan-Lei, Xinchang, Changbaishan, Qilin, Hannuoba to Liuhe, the contents of Fe are increasing in sequence, while the contents of Ni are decreasing. The values of Ni/Fe are related to olivine and pyroxene in host rocks. Trace elements including REE in fluid inclusions in lherzolite and its minerals have been determined by ICP-MS method. Normalized CO2 fluid/chondrite data show that mantle fluids are rich in REEs, especially LREEs, several times or dozen times higher than mantle rocks and mantle minerals. Fe group elements except Co and Ni tend to be poor in mantle fluids, while heavy metal elements in hydrothermal deposits, such as Cu, Mo, W, Bi and Ag, tend to be rich. Natural Au-Pt alloys was found in mantle olivine in Hainan-Leizhou area, indicating a strong deoxidization environment of upper mantle.

系统研究我国东部不同构造单元新生代碱性玄武岩中不同类型地幔捕虏体、不同矿物相中各种硫化物包裹体的成分特点、形成温度压力和区域特征。结合其它流体包裹体中挥发组分，特别是硫的状态和同位素特征研究，深入探讨我国东部地幔流体来源、演化和分布规律。在深刻认识地幔流体成矿作用、地幔交代作用和丰富区域成矿理论等方面填补某些空白。