2.6.2. Tienen Formation - Ti

Author: De Geyter (1988b).

Description: the continental-lagoonal unit mainly consists of lignitic clay and lignite, white sand, pale marl and shell beds. Locally silicified wood fragments, traces of roots and quartzites occur. Important fossil vertebrates have been found at Dormaal and Erquelinnes.

Stratotype: stratotypes have only been designated for the members.

Area: outcrops are known in the Hesbaye area and in Hainaut. The formation occurs in the subsurface in the northern part of West- and East-Flanders and in a part of northeastern Belgium with an extension to the Tienen-Landen area.

Thickness: the maximum thickness is about 35 m.

Members: the formation is subdivided into the Erquelines Mbr (Hainaut area), the Knokke Mbr (northwest Belgium), the Loksbergen Mbr (northeast Belgium) and the Dormaal Mbr (Hesbaye area).

Age: Late Thanetian (- Early Ypresian).

Remarks: the formation is also discussed by Casier (1967), De Coninck et al. (1981), De Geyter (1980, 1981), D'Omalius d'Halloy (1862), Feugueur (1955), Gulinck (1973, 1967), Kaasschieter (1961), Laga & Vandenberghe (1990), Leriche (1899, 1902), Maréchal (1993), Moorkens (1972b), Nijs & De Geyter (1984), Quinet (1966, 1969), Rutot (1881, 1884, 1903), Smith & Smith (1995), Stevens (1913), Steurbaut (1998) and Teilhard de Chardin (1927).