TRANSACTIONS OF SECTION C. 717 



Pogonatum sp. 

 Polytriclium sp. 

 Camptotliecium nitens, Schimp. 

 Hjpnum polygamum, Schimp. 



„ fluitans, Linn. 



„ revolvenSj Swartz. 



Hypnum rugosum, Ehrh. 

 „ cupressiforme, Linn. 



* „ sarmentosum, Wahl. 

 „ cuspidatum, Linn. 



• „ trifarium, Web. & Molir. 

 „ scorpioides, Linn. 



8. The Cuttings on the Crieff and Comrie Bailwmj. 

 By Henry Coates, F.B.S.E. 



As the Crieff and Comrie Railway is now being rapidly completed, the euttmgs 

 will in a very short time be covered or obscured. A record of what they presented 

 when fresh may therefore be useful. 



The line is a fraction under six miles in length, and runs almost due east and 

 west. Half-way between Crieff and Comrie it passes over the line of the great 

 fault, which approximately divides the Old Red Sandstone of the Midland valley 

 of Scotland from the Crystalline Rocks of the Highlands. The eastern or Crieff 

 section passes over the Old Red Sandstone area, and the western or Comrie section 

 passes over the Highland area. All the cuttings, of which there are seven, occur 

 in the former section. 



The first cutting, which is also the most complicated in its geological features, 

 occurs in the village of Crieff. A few yards to the west of King Street the follow- 

 ing series was exposed : — At the base, 8 feet of fine yellow sand or silt ; next, a 

 bed of boulder clay, H feel; thick, in which the boulders are very large and nume- 

 rous ; then 8i feet of peat, in which are some thin layers of sand and grit ; and, on 

 the top of all, a foot of surface soil. This bed of peat is quite local, occupying a 

 shallow basin in the boulder clay. About a hundred yards westwards, in the same 

 cutting, the Old Red Conglomerate rises up in a buttress-like mass, and forms the 

 base of the series at that point. It dips south-east at an angle of 30°. Its upper 

 surface is very much disintegrated, apparently by ice action. Resting on this disin- 

 tegrated surface is a bed of boulder clay, which to the west of Burrel Street rises 

 until it reaches a thickness of 24 feet. On the western face of this bank of boulder 

 clay there is a bed of river material. 



On either side of the valley of the Turret — which the line crosses — there are 

 cuttings through the highest river terraces. In these cuttings boulder clay is 

 exposed at the base for a depth of 3 or 4 feet, on the top of which rests a series of 

 river deposits. These latter consist of fine and coarse gravels, grits, sands, and 

 silts, all more or less distinctly bedded, the finer material frequently exhibiting false 

 bedding. In the boulder clay some of the boulders are very large and finely 

 striated. 



Two miles west from Crieff the line passes through a cutting where the Old 

 Red Sandstone is exposed tilted up in a perfectly vertical position, and, indeed, 

 bending over to a reverse angle of 78°. On the truncated edges of these beds rests 

 a deposit of boulder clay, 30 feet thick, and on the top of that 4 or 5 feet of fine 

 sand, apparently of river origin, 



The last cutting occurs three miles from Crieff, where the line is carried in a 

 tunnel through the hill on which the Baird Monument stands. The rock through 

 which the tunnel is bored is a very hard and coarse (Old Red) conglomerate. 



I am indebted to Mr. John Young, C.E., Perth, the chief engineer, and to Mr. 

 Moncur, the resident engineer, who gave me facilities for inspecting the cuttings, 

 and also placed at my disposal the plans and sections of the line. 



