120 Outlines of the Miner ahgy of the Ochil Hills. {Feb. 



1. Red Sandstone. — This rock occurs for the first time, in travel- 

 ling from east to west, on the shore below Birkliill. It is also found 

 in a quarry betuet-n Bambriech Castle and Nevvburgh; in the small 

 hills between Pitcaithly* and Dunning ; and to the westward of 

 the latter place. Its colour is a dark brick-red, brownish red, and 

 reddish grey. It is coarse-grained, occasionally it becomes conglo- 

 merated, as to the south of Dunning, where it rests on the reddish- 

 grey sandfetone, and contains considerabi* masses of quartz, fine- 

 grained sandstone, and scales of silver-white mica. This sandstone 

 is occasionally highly crystalline, bearing some resemblance to iron- 

 flint. When the mica predominates, it assumes a slaty character, 

 and decomposes into tables. 



It occurs distinctly stratified, dipping to the south-east, with an 

 apparent direction from north-east to south-west. I have not seen 

 it in connection with any other rock, except below the Rumbling 

 Bridge, in the course of the Devon, where it alternates with a 

 tuif ; and at the foot of the King's Seat, near to the house of 

 Harvieston,t where it rests immediately above a seam of slaty 

 pitch-coal, six feet two inches thick. From the resemblance of its 

 characters to those of another sandstone to be hereafter noticed, it 

 is highly probable that they will be found to belong to the same 

 formation; but as they have not been traced in distinct connection, 

 it may be well to keep them separate at present. At the base of 

 Alva Hill it seems to lie below greenstone. 



In a small valley which traverses the Ochils, between Worrait 

 Bay and a lateral valley that divides Newton Hill from Sanford 

 Hill, there are several small hillocks of an ironshot sand, which 

 contains masses of this sandstone. It is probable that they have 

 been derived from the decomposition of the red sandstone just 

 described. 



Although it has not been accurately determined, it is highly 

 probable, that this red sandstone, from the number of points at 

 which it occurs, and the coincidence between its characters and 

 Jhose of the old red sandstone which occupies the adjacent valleys, 

 that they will be hereafter found to be intimately connected. At 

 present I shall hesitate to fix the place of this rock in the system, 

 and content jnyself with observing, that it seems to be the lowest 

 of the scries composing the Ochil Hills. 



2. yhnygdalvid. — On the shore between Parton Craigs and 

 Balmerino (a district of nearly nine miles), a coarse amygdaloid 

 gradually passes into a finer variety of the same rock. The former 

 of these consists chiefly of portions^ of the latter, binding together 

 various substances. I could not discover the thickness of any of 

 the beds; but 1 apprehend, from having seen a difterent rock at a 

 small height above it, that it is inconsiderable. The basis of this 

 rocji is a greyish-green claystone, occasionally very much ironshot, 



* This ib a small village !n PerlJishire, celebrated for a mineral spring, to wliici 

 considerable cfficacj h;is been ascribed. 



+ The seat of my friend Crauford Taif, Esq. 



