Evidence for the Onshore Extension of the Deep Water Jurassic Salt Basin in the Majunga Basin, Northwest Madagascar
Nigel Banks1, Bernard Cooper1, Steven Jenkins1, and Edmond Razafindrakoto2
1Wilton Petroleum Ltd, London, United Kingdom
2Wilton Petroleum Ltd, Antananarivo, Madagascar
Previous models of basin development in western Madagascar have recognised a failed, Permo-Triassic, Karroo rift system lying landward of a Lower Jurassic rift that developed into the Middle Jurassic to present day passive margin. Features of these models are 1) the thinness of the Jurassic rift sediments (0-800m), 2) their onlapping relationship to pre-existing Karroo tilted fault blocks, 3) their shaley nature, and 4) the absence of a well-defined Jurassic rift margin. These models have been developed mainly using data from the better explored Morondava Basin.
However, in contrast, a new integrated interpretation of the onshore part of the more northerly Majunga Basin highlights a sharply-defined fault margin to the Jurassic rift basin extending for at least 200+ km parallel to the coast and a substantial thickness of early Jurassic rift sediments (500-3000+m) to the west of it.
Tari et al. (2004) provided strong evidence of
AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas