Defined at the Frænkelryggen mountain () by Kiaer in 1918, the formation was originally described as
Silurian, later dating of the formation provided likely ages between 413.5 and 411 Ma, dating the formation to the
Lochkovian stage of the
Early Devonian. The formation belongs to the
Red Bay Group, conformably overlying the
Andréebreen Formation and overlain conformably by the
Ben Nevis Formation. The formation comprises
sandstone and green
shales deposited in a
fluvial environment. == Fossil content ==