5 



132 DESCRIPTION OF TINTO. 



centre. Other specimens contain quartz passing' 

 into flint, and amygdaloidal portions of steatite. 

 Calcspar, too, is an abundant ingredient of this 

 rock. Where it joins the sandstone, there is a 

 mixture of both substances, — ^ frequent appear- 

 ance in such cases. Some miles to the westward 

 of Symington, limestone occurs ^ but I did not ex- 

 amine it, or procure specimens. 



On the other hand, the sandstone of which the 

 whole inferior districts of Lanarkshire are com- 

 posed, and which may be traced for so many 

 miles along the course of the river, I consider as 

 belonging to the same formation with the sand- 

 stone-conglomerate at the base of Tinto ; and as 

 corresponding to what is called in the Wernerian 

 system, the Old Red Sandstone. It is to the waste 

 of this rock that we owe the splendid scenery of 

 Cora- Lin, and the other celebrated Falls of the 

 Clyde, which have long attracted the notice and 

 admiration of travellers. In its descent to the 

 lower country, it appears to be still accompanied 

 with portions of the same substances which over* 

 lie it in the body of Tinto ; as porphyry -slate 

 and felspar-porphyry have been found near the 

 Cora Lin. Below the Fall of Stonebyres, the 

 rock assumes a coarser texture ; and, if I am 

 rightly informed, again exhibits a conglomerate, 

 similar to that of Tinto, by including masses of 

 transition- slate, splintery hornstone, quartz, jasper? 

 and flinty-slate. 



