The initiation and development of the Morondava Basin [Madagascar] from the Late Carboniferous to the Middle Jurassic: sedimentary, palaeontological and structural data

In the western part of Madagascar, the Morondava Basin shows the Malagasy K aroo series, made of Late Carboniferous-Mid-Permian (Sakoa), Late Permian-M id-Triassic (Sakamena) and Late Triassic-Mid-Jurassic (Isalo) sequences. Th e sedimentary facies are mainly aerial and elastic in the series, and the m arine conditions are fully established after Lower Jurassic times, when the strait between Africa and Madagascar was flooded. The Karoo basins where these series were deposited are mainly hemi-grabens. Their filling proceeded from west to east and from south to north. Distinc tion between the southern and northern part of the Morondava Basin suggests that development of the basin was controlled by old crustal weakness zones , trending north-northwest-south-southeast and north-northeast-south-southw est. (C) 1999 Elsevier Science Limited. All rights reserved.