OVERVIEW OF THE PRECAMBRIAN GEOLOGY OF MADAGASCAR

The Madagascar Island,as one of the most important Precambrian metamorphic blocks of the earth,is a significant component of the Gondwana supercontinent.Geological survey in the island has been carried out since the beginning of the 19th Century.In the last 20 years,the applications of new theories and techniques improve the study of fundamental geology.Tectonically,the Madagascar Island can be divided into five units,i.e.the Archean Antongil block,the Archean-Proterozoic Antananarivo block,the Archean Tsaratanana greenstone belt,the southern Proterozoic block and the northern Neoproterozoic block,each of which can be subdivided into different tectonic units.As a whole,Madagascar experienced the Archean basement formation and the Neoproterozoic block activation.The stage of the Neoproterozoic block activation is closely related to the formation of Gondwana supercontinent.