2.3.3. Jauche Member - JAU

Authors: Rutot & Van den Broeck (1888).

Description: From bottom to top the Cretaceous strata at Orp-Jauche comprise:

-        sands and sandy marls at the base of the white chalks;

-        calcarenitic or sandy  facies of the white chalk;

-        very fine-grained white chalk with black flints;

-        coarse-grained chalk with bed with rolled  pebbles and nodules at the base;

-        calcarenites with Thecidea papillata,  flints and a pebble bed at the base;

-        unconformably overlain by Palaeocene sands and marls with flint pebbles at the base.

Stratotype: at old quarry at Orp-le-Grand (Orp-Jauche, east Brabant).

Thickness: 0.20 m to 2 m.

Age: The Late Maastrichtian brachiopod Thecidea papillata occurs in great numbers in the Jauche Member.

Remarks: Previouslyknownas “Tuffeau d’Orp-le-Grand “ in Thielens (1871-1872), Rutot  & Van den Broeck (1887-1888), Leriche (1929), Marlière (1957). The denomination “Orp-le-Grand” was used previously by Thielens (1871-1872) for two levels in the section – one of  Maastrichtian age and one of Palaeocene age. Vincent (1873) used “Sables heersiens d’Orp-le-Grand” for this Palaeocene formation, generally today called  “Sables d’Orp”. Thus, it was necessary to introduce a new name for the Cretaceous lithostratigraphic unit, and since today Orp and Jauche belong to the same administrative unit, it was decided to name it Jauche Member.