110 FORESTRY OF NORWAY. 



argilaceous schists of this layer. Above, on its surface, 

 the layer presents on many parts a hard conglomerate, 

 erratic blocks of quartz in which appear to have come 

 from ancient quartzose mountains in like manner destroyed, 

 and among these blocks are also found fragments of the 

 old granite, pure and simple. 



No fossils have been found in this layer ; but it is 

 considered as the base of the laconic formation, and it lies 

 in a position divergent from that of the horizontal strata 

 on vertical layers of the fundamental rock. Fossils have 

 been found at Hogberg, near the river Klara Elv, to the 

 south of Kvitvolfjeld. 



Sandstone is met with on the surface of the sparagmitic 

 land in the part to the east of Trysel, whence are obtained 

 the famous white stones bearing that name. 



On the sparagmitic formations in the western part of 

 the plateau of the Oplande rests the second layer of the 

 laconic formation, composed of argilaceous micaceoui 

 schist and limestones, with rarely occurring debris of nas- 

 cent animal organisms. From the most distinctly charac- 

 teristic portion of this layer composed of black argilaceous 

 schist containing petrifractions of dictyone'mes a species 

 of bryozoes ; and from species of the genus of trilobytes 

 called olenus being found in the limestone, this layer has 

 received the designation dictyonema schists and olenus 

 limestone. It corresponds to the period of the Potsdam in 

 the United States. It covers an area of 4,500 square 

 kilometres. The argilaceous schist is readily disenti- 

 grated, and produces excellent pasture land on the moun- 

 tain summits, and in many valleys a rich arable land. 

 The same may almost be said of the limestone, the fertility 

 of which, from the decomposition of animal remains, is 

 considerable. 



In some places, as on the west shore of the Christiania 

 fiord, at the Skien fiord, to the south of Kongsberg, and 

 both banks of the south part of the Miosen lake, the 

 layer of argilaceous schist lies immediately on the funda- 

 mental rock. 



