STRATA of the GRAMPIANS. ei 
of the two former whins which I have had occafion to mention. 
Its colour is of a dark-bluifh black. In tracing, with my eye, 
its vertical cracks-and fiffures, I thought I could perceive a rude 
tendency to prifmatic forms. It is vertical in its pofition; and 
its ftretch is from weft to eatt. 
Tuts bed of whin is fucceeded by an Argillite of fhivery tex- 
ture, and confufed ftratification ; ‘but as it recedes from the 
whin, and approaches the mountains, it becomes regularly ftra- 
tified. This ftratum of flate is of great extended thicknefs ; and it 
contains a vaft variety of colour and of tint. The colours are, 
pale greyifh-blue, yellowifh-green, reddifh-brown, purple and 
black, with a great variety of tints of all thofe colours ; but the 
predominant colours are the greyifh-blue and the yellowith- 
green; of which two there are two forts; the one foft, and the 
other much indurated. The foft is thinly laminated, and fre- 
quently pafles over into the highly indurated fort, in which the 
appearance of the laminated texture is almoft loft. 
In this long fucceflion of argillite ftrata, fome fubftances oc- 
cur that are heterogeneous to its rock, fuch as jafpers, limeftone, 
&c. 
Tue jafpers are in general of a blood-red colour, and are 
much veined with white quartz: they occur in large amorphous 
maffles, and in nefts, of eliptic forms, of great variety of fize. 
One of thofe bodies of jafper, in the eliptic form, has been cut 
through by the river, and is now to be feen in the face of the 
perpendicular rock, upon each fide of the ftream. Its fize is thir- 
ty feet long, by ten broad: the points of its tran{verfe axis are 
fharp ; and it ftands upright in the argillite. The mafles-of this 
matter which occur amorphous in the argillite, are of great mag- 
nitude. I have traced one of thofe for thirty yards in extent. 
All of thofe jafpers are of great induration, and take a high po- 
lith. Both the amorphous and the eliptical formed maffes are 
found imbedded, where the argillite is of a greenifh-grey colour, 
B2 thinly 
