Bemærkninger om oversiluren i Brumunddalen

Abstract

Forkortet: The author can not agree in some points of the description of the Upper Silurian in Brumunddalen, which Mr.K.O.Bjørlykke has published in \"Norges geologiske undersøkelses Årbok\" (1904 No.2). I. The graptolitic shales near Torsæter and Mariendal according to the description of Bjørlykke are directly resting on the limestone near Torsæter. This view does not appear to be right. The limestone near Torsæter on the contrary contains a fauna, that corresponds with the fauna in the upper part of stage 6 in the southern part of the Oslo area. The graptolitic shales correspond with the graptolitic shales of Malmøya, stage 8 a. If the view of Bjørlykke is right. etage 7 could not be developed in Brumunddalen; this is improbable, as it exists in nearly, ordinary development near Gjøvik 25 km from Brumund- dalen. The profile near Gjøvik lime-mill is given after investigations of the author (pp. 4-5). Faults have probably hidden stage 7 at Torsæter. II. The sandstone in Brumunddalen, which is resting directly on the grapto- litic shales, Bjørlykke has compared with the sandstone, which in the south part of the Oslo area is resting on the Silurian. Bjørlykke has not given any arguments for this view. On the contrary the Upper Silur- ian in the valley of Oslo is demonstrating.