The information on this page is a summary description.
The full formal description is available here: Inden Formation
Abbreviation
In
Parent unit
Child units
Lithological description
A pale grey to white coarse sand, which can be darker grey coloured due to mobile organic matter content, containing particularly in the coarsest horizons small wood fragments and clay clasts. Some thin clayey horizons occur near the base of the sand. The sand contains a pollen assemblage. No carbonates occur. Dinoflagellate cysts are absent except for the very base of the unit. The resistivity signal increases upwards.
Age
The Inden Formation identified in the Belgian RVG corresponds to the latest part of the Inden Formation in the Lower Rhine Basin Inden Formation. Based on dinoflagellate content it is considered end Tortonian as discussed in Louwye & Vandenberghe (2020).
Thickness
In the Belgian part of the Roer Valley Graben (RVG), boreholes with the Inden Formation identified show a thickness of the formation in the same order of magnitude as the 26,5 m in the Maaseik reference well.
Area of occurrence
The Inden Formation as defined in the Maaseik reference borehole occurs in the Belgian part of the RVG east of the main bordering faults of Neeroeteren and Reppel as suggested by borehole correlations to Jagersborg (049W0236/ Kb18d49w-B235), Kinrooi (049W0230/ Kb18d49w-B230) and St.-Huibrechts-Lille (033W0139/Kb18d33w-B142) boreholes in fig.6 in Vandenberghe et al. (2020).
Type locality
The reference for the Inden Formation in Belgium is the166-192,5 m interval in the Maaseik (049W0220/ Kb18d49w-B220) borehole; cores, SP, Res and GR geophysical logs of the interval are available in Vandenberghe et al. (2005).
Alternative names
In older literature the Inden Formation sand was included in the ‘Waubach sand and gravel unit’.
Authors
Vandenberghe, N., & Dusar, M.
Date
01/09/2023
Cite as
Vandenberghe, N., & Dusar, M., 2023. The Inden Formation, 01/09/2023. National Commission for Stratigraphy Belgium. http://ncs.naturalsciences.be/lithostratigraphy/Inden-Formation
