La marge continentale armoricaine, résultats d'observations en submersible et de dragages dans le canyon Shamrock

Observations gathered with Cyana submersible and dredge sampling in the Shamrock canyon area during the CYMOR cruise allow us to specify the geological evolution of this part of the northern Bay of Biscay margin. At least during the Lower Cretaceous (Neocomian to Albian) there existed a subsident basin limited by highs. The hiatus located between Albian and Tertiary formations indicates that this process was interrupted during the Late Cretaceous by a possible tectonic event. From the Oligocene the sedimentation became turbiditic. Active erosion processes on the canyon flanks and turbiditic massive flows have been observed. [NOT CONTROLLED OCR]