Om de senglaciale og postglaciale nivåforandringer i Kristianiafeltet (Molluskfaunaen).

Abstract

Forkortet:The great terminal moraine ridges - the ra's - on both sides of the Oslo Fjord were formerly, especially by De Geer, commonly supposed to indicate the uttermost limit of the last great ice sheet; on pp.3-8 it is proved that this opinion cannot be right, because the land outside and inside the ra does not differ. The rock surface on both sides of the ra is equally polished and scratched, and the scratchings are equally fresh, and engraved in the same direction, etc. and the scratchings outside the ra are only covered by the group moraine or by a marine clay, the yoldia clay, that without all doubt originates from the last ice epoch. It is therefore evident that Southern Norway, (especially the Oslo Region) along the south coast, has also, during the last ice apoch, been completely covered by the land-ice out to the extreme limit of the land-mass itself, and even beyond this limit. A few years ago only one occurrence of yoldia clay with 3(4) species was known from Southern Norway. Through the investigations of the author, about 30 occurrences are known (see p.669) with species of mollusca etc.