Om oversiluren i Brumunddalen

Abstract

The Brumunddal (dal means valley) lies in the middle part of Southern Norway and ascends from the lake of Mjøsa to the North of the town of Hamar. Silurian shales and limestone, postsilurian porphyry and a sandstone occur there. The age of the sandstone has been much disputed, and it has been attributed as well to the Early Cambrian, the \"sparagmite formation\", as to the Devonian. The present writer has now found fossils in sandy shales interstratified in the lower part of it. The organic remains, Retiolites geinitzianus, Barr, and Monograptus priodon, show, that the sandstone belongs to the Upper Silurian. We have the same succession of strata here as we have in the Swedish province of Dalarne, where the corresponding sandstone has been designated as \"Slip- sandsten\", and in the Oslo district, where a non-fossiliferous sandstone rest- ing on the Silurian has been called \"etage 10\". This latter sandstone has been regarded as a representative of the Devonian, but the author thinks it is more correct to unite it with Silurian, as it is done at present with the lower part of the Old Red (containing sea animals) in the British Isles. The fossils named above show, that its equivalent in the Brumunddal are unquestionable deposits.