Tectono-Sedimentary Evolution of NW
Watkinson, Matthew P.1, Edward P. Blunt2, Mark A. Enfield3 (1) PDF Fellowship, University of Plymouth, Plymouth, United Kingdom (2) Sterling Energy plc, Harpenden, United Kingdom (3) PDF Ltd, Streatley, United Kingdom
The offshore basins of NW Madagascar
present a significant frontier exploration challenge as a result of their
complex geological evolution and a relative paucity of subsurface data. Exploration
risk is being constrained through the integration of analyses of onshore
geology and seismic sequence stratigraphy with an evaluation of the tectonic
evolution of the southern
The tectono-stratigraphy of NW Madagascar comprises seven megasequences. These can be related to Karoo extensional tectonics, Early Jurassic rifting between East Africa and Madagascar, opening of the Somali Basin-Mozambique Channel, mid-Cretaceous strike-slip tectonics, Late Cretaceous rifting between India/Seychelles and NE Madagascar and subsequently changes in the location and vectors of ocean spreading in the Indian Ocean during latest Cretaceous/Paleocene and the Cenozoic. The presence and distribution of these megasquences and the structural styles associated with them have been confirmed through a detailed evaluation of the onshore geology of NW Madagascar, including fieldwork.
The application of the tectono-stratigraphic framework to exploration offshore has been facilitated through analysis of a seismic database which has been significantly improved by reprocessing and new acquisition. And the sequence stratigraphic and structural interpretation of seismic data has provided new insights into the link between tectonics, salt behaviour and the nature and distribution of key play elements of the basins.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California