SYDNEY SANDSTONE. 463 
B. 7 feet——Similar sandstone, in some parts clouded with red; layers of deposition 
rather indistinct. Six yards to the northward, reduced to a thickness of t2o feet. 
The horizontal lines in this layer are planes separating portions of it. 
. 83 inches.—Blue clayey shale, micaceous. Disappears a few feet to the north. 
. 8 feet.—Similar to B. Discontinues abruptly, fifteen feet to the northward. 
. 4 inches.—Blue shale, similar to C, with a distinct slaty structure. Increases to three 
feet to the northward, where it replaces D. The layer is more arenaceous above ; 
it contains some vegetable impressions. 
F. 4 feet.—Gray sandstone, with brownish or black stripes in some parts ; micaceous. 
Layers of deposition one-tenth to one-sixteenth of an inch thick. 
Wo Q 
G. 2 feet—Blue micaceous shale; arenaceous; cleaves readily into thin plates or 
lamine. 
The following figure was taken at a quarry adjoining the same 
cove, but higher up the bank. The | ----——————_—____ 
irregularity of the lines of stratifica- eer 
. . : : : —_— ~ — <= 
tion is still more apparent in this 47 
al Q pa se - Saad 
figure. ‘The rock is wholly sandstone, eee oo 
excepune ione thin aroillaceous: layer © <= 
which disappears to the northward, but again appears ten feet beyond. 
The sandstone layers are generally marked distinctly with parallel 
lines. ‘They are the edges of layers of deposition, and are seldom 
over an eighth of an inch apart. They are best seen on a worn 
surface. 
The upper portion of the figure on page 462 affords an example of 
oblique deposition, of very frequent occurrence in the sandstone. Simi- 
lar facts have been described as occurring elsewhere, but I know of no 
instance of their prevailing to so large an extent as in this formation. 
The upper layer in the figure referred to, though horizontal itself, 
consists of oblique subordinate layers, dipping at an angle of about 
eighteen degrees to the northward and eastward. The next layer 
below is horizontal in structure as well as position. 
A section of only twenty feet in height at one of the quarries con- 
tains three alternations of these peculiar layers, with others of ordinary 
structure. ‘They are as follows :— 
. 6 feet.—Sandstone, composed of thin oblique layers of deposition. 
4 feet.—Sandstone, with the ordinary horizontal layers of deposition, 
3 feet.—Similar to A. 
. 4 feet.—Similar to B. 
. 3 feet.—Similar to A.; and below this horizontally deposited layers occur. 
HPoUOW> 
Look where we may, scarcely a cliff of twenty feet can be found 
