Examines the seismic stratigraphic framework of the shelf. The various acoustic reflectors observed in the area can be attributed to: a substratum S which covers the entire area; a formation A, which consists of sediments deposited in channels of fluvial origin; a formation B, which is composed of coral clasts; and two high sea-level sedimentary prisms C and D, which correspond to a near modern sea level, and are Holocene in age. The extent of these formations is controlled by the specific morphology of the acoustic substratum, which is asymmetrical on either sides of the shore-normal line extending northeast from Kourou. The influence of Amazon discharge is controlled by this feature.