Fig. 5: Ternary plot of natural and experimental data.
From: Origin of carbonatites—liquid immiscibility caught in the act
Hamilton projection70 i.e. ternary plot with CaO + MgO + FeO vs SiO2 + Al2O3 + TiO2 vs Na2O + K2O (in wt%) of the conjugating immiscible silicate (Ls) and carbonate liquid (Lc) from this study. Also plotted: calculated parental phonolite (Table 1), Sövite (Laacher See Carbonatite52, and Weidendorfer et al.’s60 Ca-carbonatitic parental “multiphase” composition (100 MPa at 1000 and 1050 °C) with liquid line of descent60 (orange line). The dashed line is the estimated binodal from this study, the solid line is the binodal determined by Kjarsgaard37 for CaO-rich nepheline at 200 MPa. For comparison, compositions of natural magmatic carbonatites57 with compositions taken from the GEOROC (Geochemistry of Rocks of the Oceans and Continents) database (http://georoc.mpch-mainz.gwdg.de/georoc/) are plotted. The heat map (highlighted in red) shows relative distribution of magmatic carbonatite compositions. Also shown is the indicated differentiation path from mantle-derived basanitic (green circle) to phonolitic magma41,44.
