A.REAS l >F < !rY8T M.I.IM: SCHI8 PS. 



Bach of the granitoid Areas (see fig. 1 I above mentioned ie flanked on all 

 sides by a belt of crystalline schists. These, by the Minnesota Survey, were 

 designated, in 1886, the Vermilion Series. A- a general formula they dip 

 away from the periphery of the Area, ami the angle of dip increases with 

 the distance until it becomes vertical (see fig. 7). In tin.- position they are 

 conformable \\ itli the newer Bemi-crystalline schists, \\ ith which they are now 



in contact, and "ii the other side of which the crystalline BChists reappear in 



vertical attitude, but soon leaning toward the next gneissoid mass. In the 

 region south of the Rainy river occurs a very extensive area of crystalline 

 BChists, but wide tracts of this arc horizontal or nearly so. [n crossing it 

 from north to Boutb we discern, first, a gradual diminution of northward 

 •lip: then an approach to horizontality, followed by a change to southward 

 dip, indicating the passage of an anticlinal. Further Bouth the southward 

 diji becomes vertical, and then a northward dip supervenes, Indicating the 

 passage of a synclinal. The northward dip continue- to contact with the 

 next gneissoid Area.* These undulations give opportunity to calculate the 

 thickness of the Vermilion series, ami give us a result in this place of 25,500 

 feet. Seldom, however, do they attain this volume. In fact, we find them 

 presenting all degrees of attenuation, down to complete disappearance. In 

 my computations I found them, in the interval between the Basswood and 

 White Iron granitoid Areas, possessing a maximum thickness of 2,1 L2 feet. 

 Around the Baganaga Area the crystalline Bchistsare little noticeable, while 

 on the Bouth Bide, iii .Minnesota, they may almost he pronounced wanting, 

 Farther east, however, in Canada, north of Gunflint and North lake-, the 

 south side of the Baganaga Ana i- found flanked by them. Observations 



made in the last region Beem to Bh0W that the crystalline schists soinetiim - 



disappear in (fit lim of strike, as if passing into gneiss.") A very remarkable 



occurrence is recorded by the .Mi ssota Survey : on Disappointment lake, 



.a-; of Snowbank, on the extreme northeastern border of the White Iron 



granitoid Area. Here i.« the first marked deviation from an east- theast 



Strike in all the distance from Tower, an interval of .... miles. The strike 



in this region bends around to north-northwest Here a bornblendic mica 

 schist becomes conglomeratic with various kinds of crystalline rock- up to a 



toot iii diameter. The howlders are mostly lenticular. After a change to a 



nondescript rock, which has received the field designation of" muscovado," 



ilogy of the Little Fork, a tributary of Rainy river, I 

 ,-i ifi.il> ii \ . w lochi \lh .1 ice /.' • .1/ 



nou ■ iiniiHi mil- in row Inferenoe 1* that thin Is the oentre of the gneisplc 



i mentioned I It may be known a* the I I - / ■ 



i ompare with i . 3. Oi ml - observations, ■' 



.11. \ . Winchell, pp, n • 119 



