Figure 1

Map of the Oslo-Asker District showing the sampled locations.
1: Huk Formation in Vollen, 2: Arnestad and Frognerkilen formations on Nakkholmen Island, 3a Solvang Formation on the Bygdøy Peninsula, 3b: Solvang Formation on Nakkholmen Island, 4: Skogerholmen Formation on Hovedøya Island. Modified after Grahn et al.49.