Zur Bildung und Stabilität von Forsterit, Talk, Serpentin, Quarz und Magnesit im System MgO-SiO 2 -H 2 O-CO 2

摘要: The equilibrium data (temperatures and CO2 content of the fluid phase) were de termined under a total pressurePf = 2 kb for following bivariant reactions in four components system MgO-SiO2 H2O-CO2: respective phase boundaries are shown aT-X CO 2, diagram (Fig. 5). probable position serpentine ⇌ forsterite + talc H2O (e), quartz magnesite (f), (x) also given theT - X CO 2. diagram. a), c), f) limit stability field paragenesis magnesite. (The brucite, which lies below 370° C small range parallel to ordinate, has been omitted Fig. 5.) — Serpentine is stable only low partial pressures CO2. If exceeds 6 mol-%, then will react according reaction c). b), d) At temperatures boundary From course c) it evident that addition give tale and, upon further supply CO2, probably intersect at temperature arround 330° C. this isobaric invariant point direct formation from be expected reaction: 1 3 H2O.