Crystal-melt equilibria involving potassium-bearing clinopyroxene as indicator of mantle-derived ultrahigh-potassic liquids: an analytical review

Partial melting of deeply subducted continental crust and the formation of quartzofeldspathic polyphase inclusions in the Sulu UHP eclogites

“…However, the origins of these extraordinary inclusions are highly speculative. Previous studies on a limited number of occurrences have attributed them to: (1) breakdown products of former UHP phases of coesite + K-cymrite [56,59] ; (2) high-K melt inclusions that have experienced UHP metamorphism, and later decomposed to K-feldspar + quartz [57] ; (3) decompression crystallization of melts after the peak UHP metamorphism [61] ; or (4) melt-rock reaction at UHP or post-UHP conditions in which K-rich melts were externally derived [62] .…”

An experimental study of dehydration melting of phengite-bearing eclogite at 1.5–3.0 GPa

“…For example, potassium feldspar is relatively less common minerals in eclogites due to lack of potassium source and fluid activity. On one hand, potassium feldspar can only be formed under pressures ≥5 GPa if potassium was exsolved from omphacite [43] . On the other hand, formation of potassium feldspar is favored under fluid-rich conditions [28] .…”

Fluid inclusions in diamonds from the Diavik mine, Canada and the evolution of diamond-forming fluids

“…1 and 9) suggest that the three fluids are genetically related. We evaluate the possible role of the following processes in the evolution of the diamond-forming fluids: (1) dissolution and melting of carbonated eclogites and peridotites, (2) cooling and crystallization of carbonates from a primary carbonatitic melt (Schrauder and Navon, 1994), (3) formation of both the silicic-HDF and the saline-HDF by immiscibility and separation of fluids formed during cooling of a parental carbonatitic melt (Perchuk et al, 2002), (4) mixing of HDFs produced under different conditions (Schrauder and Navon, 1994), (5) the modification of fluids through metasomatic interaction during percolation or flow through veins.…”