Sulfide-melt inclusions in mantle xenoliths from the Changbaishan district, Jilin province, China
中国吉林长白山地区地幔捕虏体中硫化物熔体包裹体

Mantle xenoliths are common in the Cenozoic basalts of the Changbaishan District, Jilin Province, China. Sulfide assemblages in mantle minerals can be divided into three types： isolated sulfide grains, sulfide-meh inclusions and filling sulfides in fractures. Sulfide-inch inclusions occur as single-phase sulfides, sulfide-silicate melt, and CO2-sulfide-silicate melt inclusions. Isolated sulfide grains are mainly composed of pyrrhotite, but cubanite was found occasionally. Sulfide-inch inclusions are mainly composed of pentlandite and MSS, with small amounts of chalcopyrite and talnakhite. The calculated distribution coefficient KD3 for lherzolite are similar to that of mean experimental value. The bulk sulfides in lherzolite were in equilibrium with the enclosing minerals, indicating immiscible sulfide melts captured in partial melting of upper mantle. Sulfide in fractures has higher Ni/Fe and （Fe ＋ Ni）/S than those of sulfide melt inclusions. They might represent later metasomatizing fluids in the mantle. Ni/Fe and （ Fe ＋ Ni ）/S increase from isolated grains, sulfide inclusions to sulfides in fractures. These changes were not only affected by temperature and pressure, but by geochemistry of Ni, Fe and Cu, and sulfur fugacity as well.