STRATA of the GRAMPIANS. it 



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 fifTures, I thought I could perceive a rude 

 tendency to prifmatic forms. It is vertical in its pofition; and 

 its ftretch is from weft to eaft. 



This bed of whin is fucceeded by an Argillite of fhivery tex- 

 ture, and confufed (Iratification ; but as it recedes from the 

 whin, and approaches the mountains, it becomes regularly unra- 

 tified. This ftratum of ilate 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 j but the 

 predominant colours are the greyifh-blue and the yellowifh- 

 green j of which two there are two forts ; the one foft, and the 

 other much indurated. The foft is thinly laminated, and fre- 

 quently panes over into the highly indurated fort, in which the 

 appearance of the laminated texture is almofl loft. 



In this long fucceflion of argillite ftrata, fome fubftances oc- 

 cur that are heterogeneous to its rock, fuch as jafpers, limeftone, 

 &c. 



The jafpers are in general of a blood-red colour, and are 

 much veined with white quartz : they occur in large amorphous 

 mafTes, 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 tranfverfe axis are 

 fharp ; and it ftands upright in the argillite. The mafTes -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- 

 lifh. Both the amorphous and the eliptical formed mafTes are 

 found imbedded, where the argillite is of a greeniui-grey colour, 



B 2 thinly 



