936 DR ROBERT CAMPBELL ON 
Uplands, while along the Highland Border and further northwards there was a 
movement of compression and elevation and consequent denudation. Such a theory 
affords a satisfactory explanation of the occurrence of boulders of Highland rocks in 
the Downtonian conglomerates of the Southern Uplands. 
(2) The above movements of subsidence reached the Highland Border during late 
Downtonian times. This is shown by the fact that the Downtonian rocks of Kincardine- 
shire, which include the highest beds in that group, rest unconformably on the 
Highland Border series. 
(3) While this movement of subsidence went on continuously in the central 
valley, about the end of the Downtonian period movement of compression set in 
towards the south, resulting in the production of the land area of the Southern 
Uplands, of which the southern Downtonian rocks form a part. 
(4) At the beginning of Lower Old Red Sandstone times the sonnel valley was 
flanked to north and south by mountain ranges and itself formed a subsiding area 
on which the coarse sediments derived from the rapid denudation of these mountain 
masses were deposited. 
(5) Finally, the earlier beginning of volcanic activity in the northern side of the 
midland valley may be correlated with the earlier development of movements of 
compression and elevation in that region. 
VIII. Lower Otp Rep SANDSTONE. 
The rocks of Lower Old Red Sandstone age, which occupy the greater part of 
south-eastern Kincardineshire, include coarse conglomerates, sandstones, and marls 
interbedded with lavas, tuffs, and voleanic conglomerates. The enormous thickness 
of the groups of contemporaneous volcanic rocks points to a prolonged period of 
volcanic activity, which, as we have seen above, had been initiated at least as far 
back as Downtonian times. Resting conformably on the Downtonian series, the Lower 
Old Red Sandstone is in turn overlain by rocks of Upper Old Red Sandstone age. 
The latter are found in Kincardineshire in a small area along the coast between 
East Mathers and the mouth of the North Esk, and the junction between the two 
series is everywhere a line of faulting. Near Arbroath, however, the Upper Old 
Red Sandstone rests unconformably on the Lower; and, as Dr Hicki1ne* has clearly 
shown, the latter series had undergone extensive folding and denudation before the 
deposition of the former. 
In Kincardineshire, as elsewhere, one notable characteristic of this formation is 
the paucity of organic remains. A few additions to our knowledge of the fossiliferous 
localities have been made in the course of the present research, but the paleeonto- 
logical evidence is so meagre that it has been found of little value for stratigraphical | 
purposes. Lithological evidence, on the other hand, obtained from conglomerates, 
* Geol. Mag., dec. 5, vol. v. p. 396, 1908. 
