M. Keilhau's Theory of Granite^ and other Roclcs. 889 



in the whole series ; gi-eywacke and grey wacke-slate are, in 

 fact, peculiar to the northern portion of the Mjosen, and they 

 there form broad zones, running from east to west, which alter- 

 nate with zones of limestone. The whole repose in an over- 

 lying and unconformable position upon the outgoings of the 

 primary deposits, viz. on the ends of the strata, consisting of 

 micaceous gneiss, hornblendic- gneiss, mica-slate, and hornblende- 

 slate, which have a high inclination, and end, or are as it were 

 cut off, within a surface, which, with greater or smaller hollows 

 and heights, extends itself over many hundred square Norwegian* 

 miles. In very few places transition strata lie horizontally over 

 their primary basis, or, indeed, in conformity with its surface. 

 This is, for the most part, only to be observed near the bounda- 

 ries of the territory (geologically speaking), where, when the 

 primary basis has a somewhat level surface, the superimposed 

 strata end in an abrupt termination, which proves that they 

 have extended considerably farther over the primary basis, but 

 at a later period have been destroyed, or partially carried away 

 — changes which also become apparent in this way, that we 

 often still see, for a long distance on the front of precipices, a 

 sort of thin coating of clayslate on the outgoings of the gneiss, 

 or observe other traces on the surface of the primary basis, of 

 a formerly existing covering, continued from these abrupt ter- 

 minations. But in many places abnormal formations have in- 

 truded themselves between the basis and the superincumbent 

 strata (we begin now to speak in the style of vulcanists), and 

 dislocations of these strata, deviations from the original more or 

 less horizontal position, present themselves as their most general 

 condition. We may safely state, that the dip is generally 

 greater than 45° in these districts. In many places the strata 

 rise to perpendicularity ; and, in my opinion, it cannot be de- 

 nied that this position occurs in the Christiania territory, within 

 whose boundaries we find so many, and such remarkably large 

 examples of these abnormal masses, which we shall now inves- 

 tigate more closely. 



The unstratified mountain rocks which come within the cir- 

 cuit of our formation are granite and .syenite (either with or 

 without zircons) ; a number of greenstone rocks, viz. diorite, 



* A Norwegian mile is equal to about seven English miles. — Edit. 



