Abstract

INTRODUCTION The Chilean continental margin is a plate converge nt boundary marked by the effec ts of ac tive subduc tio n since the Jurassic. T he Chilean forearc exhibits end -rnernbers of the d ifferent mass tran sfer modes that occur at con vergent marg ins: a purely tecton ically erosive margin in the north (fro m Ari ca to Valp araiso) - adjacent to the Ce ntra l Andean plate au- and an accretionary margin in the south, from Valparaiso -where the Juan Fernandez Rid ge co llides with the continental plate- to southernmost South Am eri ca. Specifie patterns and styles of deformation are rel ated to the se systems; furthermore, climatically controlled surfa ce mass tran sport is also contrasting between the se portions of the Chilean Margin. The first order geodynamic elements that control the tectonic evolution o f the rnargin are the subduction of the Nazca Plate underneath South America and the collision of oceanic rid ge s. Other, seco nd o rder elements, are the nature and volume of sed iments in the trench, and the pore f1uid pressure (H ilde , 1983 ; Von Huene, 1997; Bangs & Cande, 1997; Lohrrnan et al., 2001). The nature of the interaction between the factors that control the morphology of the margin and the evolution of the marine basins of the slope and continental Platforrn, are not yet fully understood. A record of the interplay between the kinernatics associated with the deformation induced by subduction and the ba sin form ation can be found along the continental margin. The objective o f this work is to better understand the relationship between the convergence processes and the tectono-sedimentary dev eloprnent of marine basins in the continental slope. With this purpose , nine seismic sections (VG02, from 4 to 12) have been analysed. The architecture of the ba sin s was obtained through the analyses of seismic sec tions acquired offshore Chilean coast between V y X regions, by the FONDEF.