Nerby Member (Nerbyleddet)
(Owen 1978)
(Previously termed: 4b-? Dasyporella-Kalken, Lower Sphaeronid Limestone (sensu Størmer 1945)).
Main Lithology. Nodular limestone.
Basal Stratotype. Hadeland: as for formation.
Hypostratotypes. Hadeland (top): Lunner Railway Section (Lauritzen 1973, Fig. 2), (unit) (NM 877 862): Tønnerud shore section (NM 780 922).
Definition. The Nerby Member constitutes the whole of the formation (16-7m) at Tønnerud and over all but the southeast of Hadeland. It comprises thin (up to 5cm), nodular and stylonodular limestone horizons with little or no intervening shale. The base marks a distinct change from the interbedded shales and limestones of the Furuberget Formation and except in the southeast, the top is marked by the base of the calcareous shales of the Gagnum Member of the Lunner Formation.
(From Owen et al., 1990: The Ordovician Successions of the Oslo Region, Norway. NGU Special Publication 4. Figs. refer to the printed version.