Sequence of variegated, red-brown to green, spilitic, basaltic volcanics and grey-brown to red-brown mudstones. In the type section a number of discrete lava flows can be distinguished as high sonic velocity and resistivity intervals with relatively high gamma ray readings. Other wells yield a more massive lava sequence, probably consisting of stacked flows.
Various consecutive, basaltic lava flows, poured out into an area of sparse, ephemeral fluvial sedimentation under arid to semi-arid conditions.
Marked by the first occurrence of volcanic rocks, resting either disconformably on red or grey claystones and sandstones of the Limburg Group, or conformably on similar rocks of basal Rotliegend clastics. The latter situation has not yet been established in the Netherlands.
Placed at the top of the uppermost volcanic bed. In the Netherlands the formation is observed to be disconformably overlain by the basal beds of the Zechstein Group, but it is possible that in places it is overlain by red sandstones and mudstones belonging to the Upper Rotliegend Group, a situation similar to that in the adjacent area in Germany.
