Madagascar and the amalgamation of Central Gondwana

Madagascar lay in an interesting position in Gondwana, straddling one of the largest orogens that formed as the supercontinent amalgamated. The Malagasy basement preserves a record of the timing and style of this amalgamation, and in addition contains much information as to the palaeogeography of the eastern Mozambique Ocean.Madagascar consists of a number of tectonic units that amalgamated in the Ediacaran–Cambrian. The tectonic units are: The Antongil Block; the Antananarivo Block; the Tsaratanana Sheet and the Bemarivo Belt. In addition to these, there are a number of regions dominated by Neoproterozoic metasedimentary rocks, including the Molo, Betsimisaraka, Vohibory and Androyen regions. In this review I outline these units, discuss their amalgamation history and implications for Neoproterozoic–Cambrian palaeogeography, and highlight a few key questions for future study.