MINERALOGY OF THE OCHILS. 15 



Stratified, having the general dip, direction, and 

 inclination of the whole mountain-group, 



VIII. Basaltic Clinkstone. 



From the first rise to the final termination of 

 the Ochil Hills, Clinkstone is the prevailing rock. 

 It occurs at Parton Craigs, resting on, and in one 

 instance alternating with, the amygdaloid ; from 

 Craig -in-Crune, (half way between Woodhaveii 

 and Newburgh,) it forms the summits of the hills, 

 occasionally exhibiting columns of more than 100 

 feet in height, which rise precipitously from the 

 low lands on the south bank of the Tay, and pro- 

 duce a noble and imposing effect ^, At the more 

 western portions of this district, the clinkstone is 

 connected with greenstone, felspar porphyry, and 

 compact felspar. At Westertoun, immediately 

 above the junction with the coal-field of Clack - 

 mananshire, it occurs distinctly stratified, the 

 beds being separated from each other by thin 

 seams of leek- green steatite, which contains iron 

 pyrites in considerable abundance. It occasional - 

 ly assumes the characters of basalt : at other times, 

 it is more decidedly clinkstone ; but it most gene- 



* This is remarkably the case in the hills between Craig-in^ 

 Crune, and Norman's Law. The columns there have a diame- 

 ter of from five to seven feet. They are pentagonal^ as it usual- 

 ly happens. 



