Fluids in the lithosphere, 1. Experimentally-determined wetting characteristics of CO2H2O fluids and their implications for fluid transport, host-rock physical properties, and fluid inclusion formation

摘要: Abstract The equilibrium distribution of CO2 H2O fluids in synthetic rock samples (principally dunite and quartzite) has been characterized by measurements the dihedral wetting angle, θ, resulting from 5-day annealing periods at 950–1150°C 1 GPa. For with polycrystalline quartz, θ varies systematically ∼ 57° for pure to 90° XCO2 0.9. Similarly, San Carlos olivine, 65° addition solutes (NaCl, KCl, CaF2, Na2CO3) causes a major decrease quartz/fluid system (to values as low 40°), but no effect on fluid dunite. Reconnaissance experiments other mono- polymineralic aggregates indicate universally high angles (θ ≫ 60°) upper mantle assemblages felsic compositions. diopside + H2O, 80°, large variation due crystalline anisotropy. In case does approach 0°, condition necessary be present along all grain boundaries. Because value greater than 60° precludes existence an interconnected phase rock, our results have important implications not only transport also physical properties bulk fluid/rock system. Any static must exist isolated pores located primarily corners, can occur hydrofracture. continental crust, aqueous (especially saline ones) are likely form network edges, thus contributing electrical conductivity allowing possibility porous flow or surface energy-driven infiltration.