Mr. Weaver on the 
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the mass of the tract, is not stratified. On the other hand, from 
repeated observations in the several quarries and other denuded 
portions, I am led to infer that the superficial parts or outskirts of 
this rock occasionally exhibit a disposition toward stratification. 
The quarries of Golden Hill and of Glencullen, may serve as 
examples of this structure, the one on the western and the other on 
the eastern side of the granite region. In the former, the rock is 
divided by smooth parallel seams into strata, three, four, five, and 
more feet thick, ranging north and south, and dipping east 75°. 
The quarries are opened from seventy to eighty feet in depth, and 
the regular arrangement of the rock is thus fully displayed ; but 
these strata are sometimes, though rarely, intersected by cross joints, 
under an oblique angle, which are mostly parallel to each other. In 
such cases, each stratum becomes naturally separated into tabular or 
columnar masses of a rhomboidal form. 
In Glencullen, the rock is also divided by smooth parallel seams 
into great massy strata, which range 20° east of north and west of 
south, and dip into the mountain to the westward, at an angle of 
70°. These strata vary in thickness from one foot to five, or 
upwards, but in general they are four or five feet thick. They are 
however curiously divided by other joints, which, as far as they are 
exposed in the quarries, exhibit a gently curved form, in the line of 
the direction of the strata. The same appearance prevails all the 
way down the eastern face of the mountain, wherever the rock juts 
out to the surface, particularly near the car-road leading to the 
quarries. 
It is probable, however, that the seams which I have just described, 
do not descend very deep into the granite mass, or, if they do, that 
they become indiscernible. I observed a few years since on the 
Dalkey coast, a large insulated granite rock in its natural position 2 
