Deep-dive observations and acoustic sonar imagery of an accretionary fold.Surficial deformations on the South Barbados wedge (Atlantic Ocean).

A detailed analysis of an accretionary fold has been conducted with sea-bea m bathymetric data, sonar acoustic imagery and direct observations from the French submersible Le Nautile. In particular, the tectonic framework of a sigmoidal axis fold was studied, where fault scarps and indurated blocky ri ses were observed. The directions of these structures are in agreement with the occurrence of an important wrench faulting zone, the origin of which i s the oblique convergence and 'mechanical transformation' of stresses betwe en the northern active Caribbean margin and the southern Venezuelan passive margin. Furthermore, the activity of a clay-diapiric tectonic contributes to the general complexity of the area. (C) 2000 Academie des sciences / Edi tions scientifiques et medicales Elsevier SAS.