Sur la présence d'Aptien inférieur à faciès urgonien sur la marge continentale armoricaine. Conséquences paléogéographiques

During the Secondary and Tertiary periods, the northern continental margin of the Bay of Biscay was the scene of some subsidence phenomena which lowered the continental blocks through faults. This was mainly observed off the coast of Brittany and at the entrance of the English Channel [(2), (3)]. During the Géogas cruise of the research vessel "Jean-Charcot" (October 1972), samples were taken from the Mériadzek scarp which forms one of these blocks. A dredging conducted on the southern limb of this structure (pl.) enabled the sampling of some sedimentary rocks among which some fragments of a yellow limestone containing a fauna of rudists could be found.