华北地台深部地幔流体的组成——来自金刚石不纯净组分的报道

With the advance of the study of upper mantle and the development of analyzing techniques, the study on diamonds becomes more and more important. In addition, because of the special conditions of the formation of diamond, its mechanical strength and chemical inertness, and the relationship between formation of diamond and mantle fluid (directly or indirectly), diamond is probably the best material for preserving such fluids to the surface, the impure components in diamond can provide abundant information on mantle fluid. Though the fluid constituents in diamonds are of local difference, they are still of global distribution. The existence of deep mantle fluid is confirmed by the genesis of diamond, the fluid inclusion, the solid inclusion and atom in lattice indicating mantle fluid, and the restrictive factors of fluid assemblage. The mineral assemblages coexisting with fluid inclusions in diamond include ilment + cholmite, rutile + phlogopite + olivine, zircon + carbonitite + olivine, apatite + phlogopite + olivine. Complex self-catalytic reaction in mantle fluid is revealed by phase equilibrium. The constituents of deep mantle fluid revealed by fluid inclusions in diamonds are 16. 87%, 47. 47%, 30. 90%, 3. 02% and 5. 38% of C, H, O, S, N, respectively, which is richer in H and poorer in O compared with atmosphere and hydrosphere. The deep mantle fluids are one of the sources of fluids participating in the shallow geological processes, and are of close relationship with earth evolution.