Carbonatites are a unique group of volcanic rocks. The book presents the most recent results of investigations carried out at the only existing recent carbonatite volcano (Oldoinyo Lengai, Tanzania, East Africa).

Historic and Recent Eruptive Activity of Oldoinyo Lengai.- Field Observations and Measurements of the Physical Properties of Oldoinyo Lengai Alkali Carbonatite Lavas, November 1988.- The Dynamics of Degassing at Oldoinyo Lengai.- Petrology and Geochemistry of Oldoinyo Lengai Lavas Extruded in November 1988: Magma Source, Ascent and Crystallization.- The Trace Element Composition and Petrogenesis of Natrocarbonatites.- Cathodoluminescence Observations of Natrocarbonatites and Related Peralkaline Nephelinites at Oldoinyo Lengai.- Nd and Sr Isotope Systematics of the Active Carbonatite Volcano, Oldoinyo Lengai.- Stable Isotope Characteristics of Recent Natrocarbonatites from Oldoinyo Lengai.- Decay Series Evidence for Transfer and Storage Times of Natrocarbonatite Magma.- An Assessment of the Alleged Role of Evaporites and Saline Brines in the Origin of Natrocarbonatite.- What are the Parental Magmas at Oldoinyo Lengai?.- Peralkaline Nephelinite/Carbonatite Liquid Immiscibility: Comparison of Phase Compositions in Experiments and Natural Lavas from Oldoinyo Lengai.- Experimental Constraints on the Possible Mantle Origin of Natrocarbonatite.