Page:A Treatise on Geology, volume 2.djvu/117

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CHAP. VII.
UNSTRATIFIED ROCKS.
103
a. The slaty rock.
G. The mass of granite.
g. One of the veins. The style of dotting is intended to express the fineness or coarseness of grain in the granitic mass and veins.
s. Portions of slate included in the granite vein.

region of Galloway, and some of the veins in Glen Tilt; in other cases it is very much more fine in grain, and otherwise dissimilar to the parent rock, as at St. Michael's Mount, and in the ease already mentioned at Tornidneon; and sometimes it is said by Playfair to