J 6 I'F.N'I'II KSKOI.A. M.-N. Kl. 



tlioii,L;li the îif^gregatcs o!" quartz arc a little coarsc-r in grain than tin- 

 niicrocliiK .ind oligoclasc. Frequent minute groups of myrmekite are 

 present in the l' round-mass. Kpiciote and octahedra of magnetite are 

 associated willi the hiotitc, ;ind iiiusco\-ite also occurs. 



Augengneisses from niiincroiis other localities showing the same 

 mineralogical and structural characters as the two specimens de.scribed 

 were studied, and we may state that these examples represent characteristic 

 types of the gneiss-granite on Nordfjord and More. Frequently the eyes 

 have been granulated altogether. In some examples there occur also 

 smaller eyes of oligoclase. The occurrence of epidote along with the 

 biotite is persistent, while chlorite is rather rarely present. 



Many exposures well illustrate the development of veined gneisses 

 fron; such augengneisses. I .studied the phenomenon at Maurstad near 

 Bryggen in Nordfjord. Mere occurs an augengneiss whose eyes, in the 

 most gi-anite-like variety, have been drawn out in length, but, at right 

 angles to the elongation, show almost equidimensional sections. Along 

 certain flexures (fig. 3) the eyes have been flattened out and present small 

 veinlets of feldspar. Apparently such flexures have originated before the 

 complete consolidation of the rock. The aplitic primary dikes seen here 

 have not been subjected 'to structural deformation at all, though they have 

 been thinned out. 



On the shore-rocks between Bryggen and Totland, and likewise 

 on Mandseidet in Selje, the development of the original phenocrysts 

 could be followed in further stages: They have been drawn out into long 

 thin bands and become granulated. At the same time they have continued 

 to grow further, and not only microcline but also quartz and plagioclase 

 have crystallized in the groups that originally were phenocrysts of micro- 

 cline. The interspaces between these veins become more and more enriched 

 in biotite which assumes a parallel arrangement and thus, by a kind of 

 crystallization differentiation, a veined gneiss has been gradually developed. 



The leucocratic veins and bands originated in the manner just out- 

 lined may attain considerable dimensions and they often have been folded 

 in curious ways. 



Other kinds of inhomogeneity and schlieric development frequently 

 originated by assimilation or re-fusion of basic segregations crystallized 

 earlier than the main gneiss. There are, however, in the tracts that I 

 m3^self visited, no examples of basic fragments of truly alien siliceous rocks 

 in the gneisses, although the limestones enclosed in the gneiss-masses may 

 be of a sedimentogenous origin and the gneiss in their \icinity may 

 contain assimilated materials derived from ancient sedimentary rocks. 

 Mainly, the gneiss of Nordfjord and More is altogether an 

 igneous rock. 



We shall add short pétrographie descriptions of a few examples ot 

 veined and banded gneiss. 



