400 G. Hiclding — Old Red Sandstone of Forfarshire. 



for building and paving material. The well-known Carmyllie quarries 

 are in the middle of this series. Passing upward, the 



Cairncotman Series is reached, distinguished by its coarser materials, 

 principally dull red or grey grit with bands of conglomerate. The 

 conglomerates are more particularly developed on the north side of 

 the anticline, as at Turin Hill, north of llescobie Loch. This series 

 should appear on the coast in Lunan Bay, but it is entirely hidden by 

 the sand and alluvium. At the south end of the bay another series of 

 lavas, admirably exposed for study, intervenes between it and the 



Bed Mead Series, which forms the bold cliffs from the promontory 

 of that name southward to llumness. In its lower part it consists of 

 fine red thin-bedded sandstone with bands of hard bright red shale, 

 while the upper portion is made up of thicker-bedded sandstone. 

 Some six or seven miles to the south-west, at Arbirlot, the lower part 

 of this series, as seen in the banks of the Elliot Burn, consists mainly 

 of blue and grey shales, with partings of sandstone, having so strong 

 a resemblance to some of the rocks of Carmyllie as to have led Hugh 

 Miller to consider them as a repetition of that series. This case 

 illustrates veiy well the rapid lateral variation to which all the beds 

 of the Old Red Sandstone are liable. 



The Auchmithie Conglomerate overlies the previous group in the cliffs 

 just north of the village so named. The series consists of three main 

 masses of conglomerate, with intervening sandstones and conglomerates. 

 The pebbles in the conglomerates are well rounded, fairly large 

 (generally 1 to 6 inches, rarely 12 inches), and, as usual, are 

 mostly quartzite. The thickness of this conglomerate series diminishes 

 along its outcrop to the south-west. 



The Arlroath Sandstone is the highest scries of the Lower Old Red 

 seen on the Forfarshire coast. Coarse, gritty, sometimes pebbly sand- 

 stone is its component rock, always red in colour. Just above the 

 base of the series, by the Signal Tower at Arbroath Harbour, there is 

 a single band of grey grit and marlstone on the shore, containing 

 nodules of limestone from the size of a pea to 1 foot in diameter. 

 This is noteworthy in view of the almost complete absence of lime from 

 the Lower Old Red System. In Strathmore the Geological Survey 

 traced a thin bed of limestone for some miles, and, as far as I can 

 judge, that bed occupies about the same horizon. If they should 

 prove to be the same they would form a valuable datum-line in 

 correlating the beds north and south of the anticline — at present a very 

 difficult matter. In the few old descriptions of the rocks of this 

 district other limestones are referred to (Powrie, 1861), but these 

 are either in the Margie Series (Barrow, 1901) or in the Upper 

 Old Red. 



The Edzell Shales lie in the more depressed parts of the synclinal 

 trough of Strathmore, but are not represented, so far as I am able to 

 judge, south of the anticline. They overlie the Arbroath sandstones. 

 They are generally bright red fine sandstones, shales, and marls, either 

 hard or soft, frequently mottled with small circular patches of pale 

 yellow, grey, or green, or more rarely with bands of the same colour. 

 These rocks are admirably displayed in the banks of the North Esk at 

 Edzell, and even better in the South Esk, below its junction with the 



