| Popis: |
Twelve seismic profiles (3.5 kHz) accounting for more than 1850 line kilometres over a 36,000 km 2 area were examined to evaluate the seismic stratigraphic framework of the French Guiana continental shelf. The high density of seismic data favoured a high-resolution seismic stratigraphy interpretation. Acoustic reflectors in the seismic profiles were related to sedimentological properties. The various acoustic reflectors observed in the area can be attributed to: (1) a substratum S which covers the entire area, (2) a formation A, which consists of sediments deposited in channels of fluvial origin, (3) a formation B, which is composed of coral clasts, and (4) 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. |
