Geochemical Characteristics of Carbonatites

Abstract

THE lava from Fort Portal in western Uganda, recently described by von Knorring and Du Bois¹, was considered to be carbonatitic in view of the high carbonate content and its agreement with the characteristic trace element pattern as observed among true carbonatites, which are in the main calcitic or dolomitic rocks. In pure carbonatite rocks, significant elements like iron, titanium, zirconium and niobium may be accidental or regional to some degree, whereas elements like strontium, barium, rare earths and phosphorus seem to belong to the earlier (primary) constituents of carbonatite magmas.