6 Macfarlane on the Primitive Formations 



within small distances, are only subjected to sciall, and gpnerally" 

 crradual and continuous alterations; that these do not frequently 

 shew sudden faults, or leaps in the most varied directions, 

 within a few paces. If we however examine much of the gneiss of 

 northern Bergenstift, we find exactly the opposite of this. Let 

 one only observe the profiles which the play of the waves keeps 

 so clearly and distinctly exposed on the rocky banks of Evenig- 

 fiord, Outer Dalsfiord, and especially of Sondelvsfiord. In what 

 absolute indefiniteness, in what indescribable confusion is the 

 structure of the masses exhibited ! And yet there reigns the most 

 unequivocal parallel structure within those thousand-fold mean- 

 dering windings of the single zones, in which no rule, no law is 

 evident, for the wonderful winding appear so lost in each other 

 that neither drawing nor description is able to follow them." 



In the presence of such contortions, and of local foldings on a 

 larger scale, it is of course difficult to ascertain the general strike 

 of the strata. It seems however, that in all the principal gneiss 

 regions of Norway, the rocks run most generally north and south, 

 or at least N.N.E. and S.S.W., and this, although there are nume- 

 rous exceptions, appears to be the general strike. It seems also 

 that a generalisation is possible as well with regard to the dip, as 

 to the strike of the rooks constituting this gTOup. The strata are 

 almost always vertical or nearly so. This is the distinguishing 

 character of the formation, and, en passant^ let me remark the great 

 difficulty hitherto experienced in all theorizings as to its origin. 

 Horizontal and less inclined strata have indeed been remarked in 

 several places, but they must be regarded as exceptional. The 

 dip is almost always over 45°, generally 60® to 80°, while per- 

 fectly vertical strata arc often observable. These much inclined 

 strata may be traced continuously many miles on the above men- 

 tioned north-easterly strike, and taken together, strike and dip, 

 form a remarkable feature in the architecture of these rocks. As 

 Keilhau remarks, " there lies spread out before us an area of many 

 thousand square miles, which shews only in a few places, any other 

 than steeply inclined strata. In a great many, and indeed we 

 may say in the mo^t and greatest portions of this area, we see these 

 steep strata following some law of regular course. We find 

 them stretching away ten, twenty and often many more 

 geographical miles, according to the same lines, and it ap- 

 pears to us that there where new fields of strike beginj it is still 

 the same parallel masses which we have previously observed, and 



