ns 



DESCRIPTION OF TINfO. 



At the foot of the mountain in this direction, a 

 quarry has been opened, in which I found it im- 

 possible to procure a fresh specimen. The rock 

 seems to be a fine-grained sandstone, not unlike 

 grey-wacke-slate. There is also a portion of com- 

 pact greenstone. 



Returning eastward, on the south side, we come 

 to a stream nearly opposite to Wiston Hill, in the 

 course of which, about half way down the decli- 

 vity of Tinto, compact greenstone, and a rock in- 

 termediate betwixt greenstone and porphyry- slate 

 or clinkstone, appeared i7i situ, a little above the 

 conglomerate, over which they lie. I found here 

 a vein of felspar, evidently filled from the supet- 

 incumbent formation. 



The next object of any importance, which pre- 

 sents itself in the same direction, is the Pap-Cragg. 

 Here the substances just mentioned, ascend to a 

 height not inferior to that of the slaty compact 

 felspar already described on the south-west face 

 of the acclivity ; but I could not discover the line 

 of their junction with the felspar rock. The Pap- 

 Cragg is an abrupt conspicuous front of some size 

 and extent, containing greenstone, and greenstone 

 with specks of earthy or mealy zeolite, which give 

 it the appearance of an exact porphyry- slate. 

 Among the debris below the Cragg, fragments of 

 clinkstone occur abundantly. 



A little farther towards the east, and at an ele- 

 vation somewhat lower, the conglomerate appears 

 ^t its greatest height } and from this point,, seems 



