Large Modern Deep-Sea Fans: The Amazon Channel Versus the Zaire Channel

Nathalie Babonneau¹, Bruno Savoye¹, Laurence Droz², Alain Morash³, and Martine Bez^3
1 IFREMER, Plouzane, France
² CNRS, Plouzané, France
³ TOTAL, Pau, France

Since the 80's, the Amazon deep-sea fan remains the reference of modern reservoir analog of turbidite environments. Studies, based on seismic surveys, GLORIA and seabeam data and ODP well cores (Leg 155), initiated the main concepts and models about large deep-sea fans and meandering turbidite channels (Damuth et al., 1988; Manley and Flood, 1988; Pirmez and Flood, 1995; Flood et al., 1997).

Discoveries of deep-water reservoir in the Gulf of Guinea in the 90's led TOTAL and IFREMER to elaborate the ZaïAngo research project, in order to study the Zaire/Congo deep-sea fan at the regional scale and to understand sedimentary architectures at the reservoir scale with very high-resolution tools. ZaïAngo data, acquired over the Zaire fan, induced new insights of the understanding of large turbidite channels, for example concerning channel incision, levee development, meander migration, avulsion processes, and distal lobe architecture (Savoye et al., 2000; Babonneau et al., 2002; Droz et al., 2003). In spite of similar fan size, the Zaire channel and the Amazon channel are relatively different in terms of sedimentary architecture and channel behaviour (incision versus aggradation).

The insights and the news questions revealed by ZaïAngo studies led IFREMER to re-explore the Amazon Channel, with high-resolution bathymetric and seismic tools. Combined with ODP data and ZaïAngo results, the study of Lobestory data offers new elements to elaborate a detailed model of the sedimentary architecture of large meandering channel, to understand flow process responsible of channel development and to identify the main controls on channel development and evolution.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005