Type Oceanographic cruise
Ship L'Atalante
Ship owner Ifremer
Dates 21/10/2016 - 15/11/2016
Chief scientist(s) GRAINDORGE David , KLINGELHOEFER Frauke ORCID



Technopôle Brest-Iroise

Rue Dumont d'Urville

29280 Plouzané

DOI 10.17600/16001400
Objective This cruise is proposed to provide new answer on the dynamics and the evolution of transform passive continental margins. The objective is more precisely to characterize the crustal structure and evolution of marginal plateaux, sub-marine reliefs that are associated to 30 % of the transform margins in the world. These reliefs are systematically observed at the junction of different ages in relay zones between divergent and transform segments. Their building remains enigmatic although they represent reliefs established in geodynamical nubs that are keys ton understand the localisation of transform margins. This project MARGATS intend to image the deep structure of the marginal plateau (wide angle seismic and multichannel seismic MCS). The experimental site proposed is the Demerara plateau offshore French Guyana and Surinam and located at the junction between Central Atlantic locally opened in a divergent mode and Equatorial Atlantic opened mainly in transform mode in the area. Hence, this plateau has recorded at its different borders the divergent opening of the central Atlantic and the tranform opening of the Equatorial Atlantic. It may be this situation itself that leads to the formation of the plateau, but it requires to precisely constraint its deep internal structure. Finally the Demerara plateau is one of the more studied with petroleum seismic data and high resolution seismic data. It is then one of the ideal place to conduct a high resolution wide-angle deep seismic survey.

Published data

Klingelhoefer Frauke, Roest Walter, Graindorge David (2021). Raw data from a wide-angle seismic survey offshore French Guyana and Surinam.

Data managed by SISMER