JVeic Featiires I'u Geolcxjy of Minnesota. — Wincliell. 45 
of lateral intrusion of thin sheets of eruptive matter at this 
point. 
1. There is an infinity of the granitic interlaminations 
coincident with the strata of the mica schist. 
2. Sometimes these interlaminations consist largely or even 
wholly of quartz;. 
3. Sometimes they are very coarse like pegmatite. 
■4. Sometimes they consist almost wholly of red coarse 
crystals of orthoclase. 
5. Sometimes the red color is not separated from the 
gray. 
6. A dike of red granite that cuts across the strike of the 
schist, three inches in width, in one place shows a transition 
abruptly to the schist, but in following it along, the dike is 
seen to lose its individuality by fading out on one side into 
the schist and for some inches the two rocks are blended, but 
on the other side the contact line remained nearly as distinct. 
The point at which the rocks are blended is marked by an ir- 
regular spur or nodule of more perfect granite but associated 
with this nodule is a small mass of vein quartz, showing that 
the generation of vein quartz had a close causal and contem- 
porary connection with that force which generated the more 
perfect granite. 
7. The granitic interlaminations, which pervade the whole 
mass, are so numerous that they really give character and a 
reddish color to the whole, and where the rock is weathered 
it all appears red as if the schist itself had nearly the same 
nature as the granitic interlaminations. 
8. Besides the granitic interlaminations and the approxi- 
mate conversion of the whole into gneiss, the rock contains a 
great many irregular nodules, and lenticular masses, varying 
in size from that of a walnut to areas several feet across, but 
mostly less than six inches, which consist of granite, but 
which cannot be referred to a normal intrusion of molten rock. 
They are entirely isolated, one from the other, and they some- 
times give the dark mica schist a curiously blotched aspect. 
9. While the blotches assume, sometimes, elongated shapes, 
the elongation being usually parallel with the stratification, 
they are sometimes very thin, varying from a quarter of an 
inch to several feet. 
