4.2.10. Comblain-la-Tour Formation - CLT
Authors: Thorez et al., 1977, 1988; Thorez & Dreesen, 1986.
Description: The Comblain-la-Tour Fm is essentially a sandy deposit with arkosic beds, interlayered with thin beds of more clayey micaceous material and occasional crinoidal limestones. It has been related to an open marine-proximal subtidal depositional environment. Members are also distinguished : the Poulseur Mbr to the N-NE and the Haversin Mbr to the S-SW.
Stratotype: Ourthe valley, old quarry of Comblain-la-Tour.
Area: Dinant Synclinorium.
Thickness: ±150 m at Comblain-la-Tour.
Age: Upper part of the Middle Famennian (Fa2b). Sc. velifer and P. trachytera conodont zones in the Hamoir-Ferrière area.