The information on this page is a summary description.
The full formal description is available here: Attert Formation
Abbreviation
ATT
Parent unit
Child units
Lithological description
Greenish or purplish marl and dolomitic marl (“marnolithes”), interbedded with decimetric white dolomitic lenses, some clay, conglomeratic argillaceous sandstone, and occasionally conglomerate with dolomitic cement. In boreholes, gypsum layers.
Age
The Attert Formation is dated from Late Triassic. The first miospore-rich bed below the Rhaetian Sandstone shows a Carnian assemblage as described in the “Grès à roseaux” (Biard, 1963; Van der Eem, 1974 in Schuurman, 1977). The vertebrate fauna discovered in the upper Bunte Mergel at Medernach favors a Late Triassic age (?Late Norian), as this assemblage closely resembles those found in the Knollenmergel in Germany (Duffin, 1993; Cuny et al., 1995).
Thickness
Its thickness seems to increase regularly from west to east and from north to south, to reach a maximum of some 50 m in the neighbourhood of Attert. In the central area, at Habay, the formation is only 30 m thick. It disappears then west of Marbehan. In subsurface, in the Latour borehole, the Attert Formation reaches a hundred meters, bearing increasingly conglomeratic facies.
Area of occurrence
The formation outcrops in the north-eastern part of Belgian Lorraine.
Type locality
Access to the N4 road, close to Attert.
Alternative names
Authors
Boulvain, F., Belanger, I., Delsate, D., Ghysel, P., Godefrout, P., Laloux, M., Monteyne, R. & Roche, M.
Date
01/01/2001
Cite as
Boulvain, F., Belanger, I., Delsate, D., Ghysel, P., Godefrout, P., Laloux, M., Monteyne, R. & Roche, M., 2001. The Attert Formation, 01/01/2001. National Commission for Stratigraphy Belgium. http://ncs.naturalsciences.be/lithostratigraphy/Attert-Formation
