22 
right angles to the main Quyon fault. On the east side of this 
minor fault so much is covered that it is not possible exactly to 
correlate the beds with those on the west side of it except near 
the top of the formation. Several covered areas occur in which 
there are probably further irregularities in the angle of the dip 
as shown by the accompanying section, page 28, which in the 
Chazy beds deals mainly with the west side of the minor fault. 
These disturbances and irregularities may account for 
the Chazy limestones and shales apparently having a much 
greater thickness than farther east. 1 Between the Chazy form- 
ation and the lowest exposure of the Black River is the long 
terrace noted above. The Black River and Trenton exposures 
above this are undisturbed except for the slight general dip 
to the south and east. 
The Trenton limestone is coarse-grained and of a dove- 
tinted colour that weathers to grey. Some of the beds appear 
massive but when weathered they break up into thin layers. 
The Rockland quarry contains numerous layers of brownish 
shales from 2 to 8 inches thick which weather light. These 
shales abound in well-preserved fossils. They are only very 
slightly represented in the Ottawa section and even the few 
layers that exist do not have the abundant fauna. These shales 
are almost completely absent at MacLaren landing. The T renton 
section at MacLaren landing is taken from the edge of a plateau- 
like area. The plateau is long and narrow stretching out in a 
southeastern, direction, having the general south and east dip 
of the Trenton beds that form it. The list of fossils on page 30 
includes species from the top of this plateau, farther around the 
hill than the limited area just at the top of the MacLaren Land- 
ing section. From con. XII, lot 24 (6132), Fitzroy tp., to the 
southwest of this area, pieces of coarse Trenton limestone 
include some small, worn, irregular, limestone pebbles. The bed 
was not found in the MacLaren Landing section. 
The Black River limestone is finer-grained and purer grey 
than the beds above. The shales are very dark and, like the 
shales of the Trenton, they thin out farther west. The Leray 
member of the Black River is heavy-bedded, fine- textured, and 
x See synoptic table by H. M. Ami. 
