Adams—Contribution to our knowledge of the Laurentian. 61 
The attitude of the various members of the complex to one 
another in the eastern portion of the area is seen in the section 
A—B, which covers a distance of twenty-seven miles across the 
strike. The scale of the section is a true one, the angles of dip 
not being exaggerated, but it is double that of the map, thus 
enabling the structure to be more distinctly seen. The 
gneisses which on the west dip at angles of 40°, toward 
the east become nearly flat, often quite so, and these nearly 
flat gneisses extend to the north and east far beyond the 
limits of the map, underlying an area of several thousand 
square miles and often presenting low quaquaversal dips sug- 
gesting most forcibly a thin crust buoyed up by some semi- 
fluid or plastic material below. This is probably a great bath- 
olitie granite mass of which the Brandon granite is a portion 
laid there by erosion. 
Throughout this area of flat-lying rocks, the gneisses with 
their interstratified limestones and quartzites are as highly 
crystalline as in the most highly contorted districts and have 
evidently undergone an extensive stretching or rolling out, 
resulting in the tearing apart of the less plastic bands with the 
flowing of the material of the more plastic bands into the 
spaces between the separated fragments. ‘This is also very - 
noticeable about the eastern border of the Morin anorthosite 
where the movement along the contact above referred to has 
taken place. The appearance presented by the horizontally 
banded rocks of this area when seen in section is shown in the 
accompanying plate (II), reproduced from a photograph of a cliff 
which bounds the valley of the Black River at a point about 
two miles northwest of St. Jean de Matha, and about three 
miles southwest of the township of Brandon, the rocks here 
consisting of bands of garnetiferous quartzite and garnetifer- 
ous quartzose gneiss, with some bands of very rusty weather- 
ing gneiss to be more particularly described further on. 
Owing to the fact that investigations in recent years have 
shown, that while foliation is almost invariably the result of 
pressure even banding may in some cases be induced in massive 
rocks by this agency, the banded character of these rocks can 
no longer be considered as such indubitable evidence of origi- 
nal stratification as it has been hitherto regarded by some 
writers. It is conceivable that a complicated series of igneous 
rocks intruded through one another in the form of a net work 
of dikes and larger eruptive masses, or a series of eruptive 
masses in which irregularities In composition have been pro- 
duced by the processes at work during the cooling of molten 
magmas, which processes have recently attracted so much 
attention, if subjected to enormous movements, rolled out very 
thin as it were, might develop an apparently bedded structure. 
