Discussion of recent papers on carbonated peridotite, bearing on mantle metasomatism and magmatism

摘要: The solidus temperature for peridotite-CO_2 drops sharply within a narrow interval, with increasing pressure, to an invariant point where dolomite becomes stable at the solidus. This geometry presents barrier some volatile-charged magmas rising through lithosphere, many petrological applications. phase relationships are based on results in model system CaO-MgO-SiO_2-CO_2, and peridotite-CO_2-H_2O. Two published sets of experimental amphibole-dolomite-peridotite here interpreted terms topology peridotite-CO_2-H_2O, conclusion that two yield quite different values pressure significant peridotite-CO_2: 17 kbar or 27 (equivalent 30 km upper mantle). Better definition this clarification intersecting stability fields dolomite, amphibole phlogopite peridotite-vapor solidus, essential understanding magmatic metasomatic processes petrogenesis alkaline associated carbonatites.