Fig. 1: TIMA mineral identification maps of the experimental runs reveal distinct pressure-dependent variations in mineral assemblages.
From: Formation of giant carbonatite rare earth deposits controlled by deep-seated magma chambers
Figures 1a, b show the low-pressure experimental runs at 0.2 and 0.3 GPa, respectively; Fig. 1c–e present the high-pressure experimental runs at 0.4, 0.5, and 0.6 GPa, respectively. High-pressure experimental runs (0.4, 0.5 and 0.6 GPa) produce products that systematically differ from their low-pressure counterparts (0.2 and 0.3 GPa) in three key aspects: the earlier crystallization of olivine relative to apatite, a suppressed abundance of apatite, and the late-stage formation of abundant REE- and P-rich carbonate minerals (e.g., bonshtedtite, eitelite, and burbankite). The most notable feature is the exclusive occurrence of abundant burbankite (red-colored mineral) in high-pressure experiments ( > 0.3 GPa), demonstrating that pressure exerts a critical control on late-stage LREE enrichment.
