Grinda Member
(Grindleddet).
(Owen 1978)
Main Lithologies. Shale with limestone nodules and beds.
Basal Stratotype. Hadeland: Grinda (Owen 1978, Fig. 9A) (NM 845 874 - 848 872).
Hypostratotype. Hadeland: North of Korsrudtjern (Owen 1978, Fig. 9B (NM 836 884).
Definition. The Grinda (formerly spelled Grille) Member is composed of shales with some limestone beds and nodules. It overlies and passes northwards into the Gamme Formation and over most of its outcrop it is overlain by, and passes southwards into the limestones, siltstones and shales of Kjørrven Formation. In its most northerly development, seen in the hypostratotype, it is overlain by the Kalvsjøen Formation.
Fauna and Age. The diverse shelly fauna is very similar to that of the Kjørrven Formation (Owen 1981 p.8, Table 1) and indicates a Rawtheyan age (see below).
(From Owen et al., 1990: The Ordovician Successions of the Oslo Region, Norway. NGU Special Publication 4. Figs. refer to the printed version.