232 STRATIGKAPHICAL GEOLOGY 



is here nearly parallel to the strike. Mr. Hickling estimated 

 their thickness to be 5000 feet, and the comparative narrowness of 

 their outcrop is due to their high inclination. The conglomerates 

 of this group consist partly of quartzite pebbles, derived from the 

 quartzites of the Highlands, and partly of angular and subangular 

 fragments of jasper, chert, and " green-rock " derived from the 

 "Margie Series" (see p. 97), showing this series must then have 

 had a considerable northward extension over the Highland region. 

 The Dunottar Group is succeeded by the Sidlaw Group, which 

 includes the contemporaneous lavas of the Sidlaw Hills and the 

 overlying grey sandstones and flagstones (?500 feet), which are 

 followed by beds of coarser grain (the Cairnconnon Group), and 

 perhaps 2000 feet thick. The fourth group is the Red Head 

 Series, which consists of red sandstones with bands of hard red 

 shale, and locally some bluish - grey shales. These beds are 

 overlain by the Auchmithie conglomerate from 600 to 800 feet 

 thick, and mainly composed of large rounded pebbles of quartzite. 

 No fossils have yet been found in any of the beds above 

 enumerated, except a few in the Bed Head Series. 



The succeeding Arbroath sandstones comprise coarse gritty 

 sandstones and some flagstones, both of red and grey colours, with 

 a single bed of marly limestone at Arbroath, probably on the same 

 horizon as a limestone which has been mapped inland to the 

 westward. Fossils have been found at four horizons in these beds, 

 and include Cephalaspis Lyelli, Pterygotus anglicus, Kampecaris 

 forfarensis, and the plant Parka decipiens. 



The highest beds of the whole series (the Edzell shales) are not 

 exposed on the coast, but only occur in the deeper parts of the 

 synclinal trough of Strathmore (see Fig. 78). The following is a 

 tabular resume of the succession and thicknesses : 



Feet. 



Edzell shales 1,000 



Arbroath sandstones .... 1,200 



Auchmithie conglomerate .... 800 



Red Head Series 1,500 



Cairnconnon Group ..... 2,000 

 Carmyllie or Sidlaw Group . . . 1,000 

 Dunottar conglomerate .... 5,000 



12,500 



[I am indebted to Mr. Hickling for the drawing of the section across 

 For far, from which Fig. 78 has been made.] 



The great series of sandstones, conglomerates, and volcanic 

 rocks above described forms a continuous band across Scotland 

 from the coasts of Kincardine and Forfar to that of Dumbarton on 



