Derivation of name. The beach section at Steinsodden is designated as the stratotype, but the names Stein and Steinsholmen are pre-occupied by Ordovician lithostratigraphic units (see Rasmussen & Bruton 1994), hence the name Redalen Member is proposed in order to avoid misunderstandings. The new name alludes to the nearby exposure on the western shore of Lake Mjøsa just north of Redalen (see Vogt 1924).
Stratotype. The Lower Allochthon section at Steinsodden (Vogt 1924; Skjeseth 1963, fig. 16) is designated as the stratotype. The strata are overturned but otherwise little affected by tectonism and here both the lower and upper boundaries of the new member are exposed. The lower part of the log shown in Figure 9 is based on this exposure, which is most instructive, when the water level is low in Lake Mjøsa.
Lithology. The heterolithic unit consists of thin-bedded silt- and mudstones with numerous sandstone beds (all beds and interbeds are generally 1-2 cm thick, but a few sandstone beds are up to 5-15 cm). At Steinsodden the sandstone beds are somewhat thicker in the basal c. 5 m forming a fining-upward succession. In the uppermost 5-6 m of the member there is a slightly higher frequency of sandstone beds, 2-5 cm thick, but this coarsening upward trend is subtle. Trace fossils are very common. For description of lithology, see Vogt (1924).
Boundaries. The new member rests unconformably on the Vangsås Formation at Steinsodden and Redalen and conformably on the Brennsætersag Member at Strandbergsodden. The Redalen Member is in turn conformably overlain by the Tømten Member. Although there is no sedimentary break, the upper boundary can be identified within a metre as the lithologic shift is quite rapid; there are no sandy inter-beds in the Tømten Member of the Lower Allochthon.
Distribution and thickness. The member is restricted to the eastern part of the Lower Allochthon around Lake Mjøsa, where it is exposed at Ringstranda, Strandbergsodden, Skyberg (in the yard at the farmhouse), Steinsodden and north of Redalen. The new member is c. 36 m thick in the relatively undisturbed exposure at Steinsodden, which is the only site where the thickness can be measured (new measurement; Vogt (1924) estimated a thickness of c. 40 m). The Redalen Member is absent in the Autochthon and Parautochthon as well as in the higher thrust slices of the Lower Allochthon (e.g. Bråstad River section). Here the Tømten Member rests directly on a thin Brennsætersag Member (cf. Vogt 1924), and the lower part of the Tømten Member is probably coeval with the Redalen Member (Fig. 8).
Age. No fossils are known from the Redalen Member.
Remarks. This characteristic unit is inferred representing a lateral equivalent of the Brennsætersag Member of the Autochthon and the Parautochthon (Fig. 8). The occasional absence of the Brennsætersag Member in the Lower Allochthon indicates that the unconformity separating the Vangsås and Ringstrand formations locally is slightly more extensive.
From: A.T. Nielsen & N.H. Schovsbo, 2007