Stratotype. Evjevika was designated as stratotype for the 1b-beta zone by Skjeseth (1963). However, the Evjevik Member is poorly exposed at this site and visible only during extremely low water level in Lake Mjøsa. The easily accessible nearby exposure at Skyberg is significantly more instructive and is designated as a hypostratotype section. A simplified log of this section was shown by Vidal & Nystuen (1991, fig. 5); the upper part of the log shown in Figure 9 is based on the Skyberg exposure.
Lithology. The member consists of two bioclastic limestone beds (each typically 0.20-0.25 m thick), usually separated by 0.5-1 m of mudstone.
Boundaries. The lower and upper boundaries of the Evjevik Member are well-defined and readily identified, being located at the base and the top of the limestone beds encasing this unit. The surrounding units consist of mudstones.
Distribution and thickness. The member is known only from the Lower Allochthon of the Mjøsa District, where it usually is around 1-1.5m, rarely up to 2 m thick (Skjeseth 1963; Høyberget, personal communication 2005). The equivalent level is not preserved in the Parautochthon or the Autochthon (Hawke Bay unconformity).
Age. The limestone beds of the Evjevik Member con- tain trilobites characteristic of the 'Ornamentaspis' lin- narssoni Zone (Kiær 1917; Nikolaisen 1986; Ahlberg 1984). No age-diagnostic acritarchs have been repor- ted from the unit so far.
Remarks. The member has previously been referred to as Strenuella limestone (Kiær 1917) and Evjevik limestone/1b-beta (Skjeseth 1963). It is a border line case whether this unit should be ranked as a member or as two individual marker limestone beds, but for his- torical reasons a distinction as member is suggested.
From: A.T. Nielsen & N.H. Schovsbo, 2007