1890.] GEOLOGISKE IAGTTAGELSER FRA TRONDHJEMS STIFT. 53 



Geologi cal Notes from the Diocese of Trondhjem. 



(A Summary of the Contents). 



I. Introduction. 



Tbe following observations are collected for the Geological 

 Survey of Norway during the summer 1889. 



In his valuable works on the regional-metamorphic Silurian 

 in the Diocese of Trondhjem, Kjerulf has depicted the geological 

 relations as being more similar to the Christiania Silurian (with 

 its attendant eruptives) than one would be inclined to consider 

 it at the present time. The rocks in the Christiania district are, 

 as it is known, (with the exception of the lime-sandstone of 

 etage 5) formed in an open sea; the individual beds have a 

 greåt extension and may be traced far and wide throughout 

 the system of folds. The eruptive rocks have penetrated long 

 after the folding process. 



It is quite different in the Diocese of Trondhjem. Here the 

 beds are in great part or perhaps mostly shore-formations charac- 

 teri^ed by the occurrence of conglomerates and sandstones. 



Among the eruptives we have first greater and smaller 

 masses of dioritic and granitic rocks. The dioritic rocks 

 are probably chiefly altered gabbro. The eruptives in the 

 Trondhjem district are usually folded together with the stratified 



