STRATA of the CRAMPIANS. > 
of the rock: they are formed of the fame materials with the 
other parts of the ftone; but into them the ferruginous ftaining 
matter has not apparently been able to penetrate, and they de- 
rive their prefent greyifh appearance from the natural -colour of 
its particles of quartz, which are here per /e of a bluifh-white 
tint. This rock, in the plain, is perfectly horizontal in its pofi- 
tion; but upon its approach towards the undulated grounds, 
which here form the loweft bafis of the Grampians, it begins to 
rife from its horizontal bed, and, gradually increafing in its ac- 
clivity towards the mountains, it at laft arrives at a pofition per- 
fectly vertical. 
For the firft quarter of a mile from where this grit begins to 
leave its horizontal pofition, the rife is very gradual; but after 
that diftance, it becomes more rapid, and in a mile it gains its 
vertical pofition. 
WHERE this grit or fandftone rock is in its moft folid ftate, 
and where its pofition is perfectly vertical, betwixt two beds or 
layers of it, there occurs a bed of Whinftone forty feet broad. 
THE main body of this bed of whin interfeéts none of the 
layers of grit, but ftands upright betwixt two of them, to both 
of which it is clofely joined. The river, at this place, has, in its 
paflage, worn down this bed of whin equally with that of the 
adjoining grit, and a perpendicular face of it can be examined 
upon each fide of the river, from fifty to fixty feet in height. 
Uron examining the fection of this bed, I found upon the eaft 
fide of the river two branches, which fprung from the main body 
of the whin, nearly where the water of the river at prefent wafhes 
the bafe of its perpendicular furface. One of thofe branches 
{prings from the right fide of the trunk, and the other {prings 
from the left fide; they at firft diverge from the trunk as they 
‘afcend, and where they pufh out laterally, they interfect the con- 
tiguous ftrata, and penetrate them in a zig-zag manner; but at 
laft, in a pofition betwixt two of the layers of the grit, they con- 
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tmue 
