Age: Lower part of the Campanian (80 My.)
Thickness: 50 to 100 metres
Description of the unit:
It is a siliceous homogeneous formation. The base of the unit is a fine sandstone, highly bioturbated with nice plane and parallel laminations. Above appear some channel structures and other erosive features with normally graded beds or cross bedding. Some fine and dark clay layers rich in organic constituents may be associated with tidal structures. These dark clays are most of the time observed reworked in soft pebbles at the base of the erosive structures. Most of the formation is of fluvial origin, but there is a shallow marine influence at the base.