Experimental Data for Reactions in Siliceous Marbles

Reactions involving the phases quartz-calcite-dolomite-talc-tremolite-diopside-forsterite-enstatite-fluid have been studied experimentally in the system $$CaO-MgO-SiO_{2}C-O-H$$ by a solid-phase buffer technique. If the components of the fluid phase are limited to $$CO_{2}$$ and $$H_{2}O$$, a total of 49 reactions can be written among the phases listed. Only five of the 49 reactions are independent, and measured equilibrium constants for the following five reactions are used to derive data for the remaining 44 equations (T = temperature, degrees Kelvin; Ρ = total pressure, barometers): $$Talc = 3 Enstatite + Quartz + H_{2}O log_{10} K = -7,422/T + 10.54 + [0.104 (P - 2,000)]/, T, Talc + 3 Calcite + 2 Quartz = 3 Diopside + 3 CO_{2} + H_{2}O log_{10} K = -12,930/T + 29.16 + [0.494 (P - 2,000)]/, T, Tremolite = 2 Diopside + 3 Enstatite + Quartz + H_{2}O log_{10} K = -6,977/T + 9.33 + [0.125 (P - 2,000)]/, T, 3 Dolomite + 4 Quartz + H_{2}O = Talc + 3 Calcite + 3 CO_{2} log_{10}K = -14,330/T + 25.68 + [0.190 (P - 2,000)]/, P, 4 Talc + 5 Dolomite = 5 Diopside + 6 Forsterite + 10 CO_{2} + 4 H_{2}O log_{10} K = -75,400/T + 133.7 + [1.348 (P - 2,000)]/ T.$$