Evolution of Carbonatite Magmas in the Upper Mantle and Crust

Carbonatites are the most silica-poor magmas known and are amongst Earth’smostenigmaticigneousrocks.Theycrystallisetorocksdominated by the carbonate minerals calcite and dolomite. We review models for carbonatite petrogenesis, including direct partial melting of mantle lithologies, exsolution from silica-undersaturated alkali silicate melts, or direct fractionation of carbonated silicate melts to carbonate-rich residual melts. We also briefly discuss carbonatite–mantle wall-rock reactions and other processes at mid- to upper crustal depths, including fenitisation, overprinting by carbohydrothermal fluids, and reaction between carbonatite melt and crustal lithologies.