Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

carried out now allows to draw significant faults and their relative age based on seismo-stratigraphic constraints (Figure 2). The main faults are LHDF1 and LHDF2 in the north, N100°E in strike, which affect the Jurassic to Eocene series with no evidence of later offset, to date. The faults LHOF, LHCF and AF mainly intersect Proterozoic to Paleozoic series of the Armorican Massif; however, they notably control the post-Eocene (Neogene?) accumulations, especially at the southern edge of the La Hague Deep (Figure 2). To understand the vertical dimension, we use seismic-reflection data that cover a linear of nearly 2000 km. Some data were acquired with a monotrace Sparker in the late 1990s between Jersey and the Norman coast (Baize, 1998). Probing the first tens of meters, they show that this offshore area is occupied by a large post-eocene basin (Ecréhous basin: E) bordered to the north by a segmented fault of ~10 km (Figure 3). Fig. 3: Map of seismic units of the Ecréhous Basin (E). Bold black lines represent the faults that cut the post-Eocene infilling separated into two seismo-stratigraphic units of unknown age. From Lubert (2022).