2.11.1.1. Berg Member

Name

The name was introduced by Van Den Broeck (1883) in an explanatory note of the geological map Bilzen (scale 1/20.000). Berg is a hamlet northeast of Tongeren, and is a dependent municipality of the city of Tongeren (Limburg province).

General characteristics

Dark and flattened flint nodules are present in the base of the Berg Sands. The sands consist in the area Leuven-Tienen-Tongeren area of yellowish to white, slightly glauconitic, medium-grained quartz sands (modal value of grain size 100-175 µm). The littoral sands are homogenous to - especially in the lower part of the member - horizontally layered. Molluscs are occasionally present (a.o. Astarte, Glycymeris and Cyprina) (Glibert & de Heinzelin, 1954; Glibert, 1955 & 1957).

Occurrence

The Berg Member occurs in the Leuven-Tienen-Tongeren area, and slightly north of this area. The upper boundary of the member is with the superjacent Boom Formation or the Kleine-Spouwen Member, while the lower boundary is with the underlying Tongeren Group. The thickness of the Berg Member is maximum 5 m.

Stratotype

Van Den Broeck refers to the "gîte classique de Berg", an outcrop along a southward oriented road on the southern slope of the small hill on which the hamlet Berg is located.

For references concerning this site: Glibert & de Heinzelin, 1954 (p. 301, point 200); archives Belgian Geological Survey: nr. 93W-243; map 34/1-2 (Bilzen-Veldwezelt).

Co-ordinates: X = 233.040; Y = 171.340; Z = + 105 m.

Former designations

Geological map 1/40.000: R1b (+ R1a basal gravel)

Stratigraphical register (1929, 1932): R1

New geological map 1/50.000: BiBe.