A. Champernoivne — Age of the Ashhurton Limedone. 415 



passing up into a group of quartzose grits red and greyish, inter- 

 stratified with purplish and variegated sandy shales — the Lincombe 

 and Warberry grils^ — with some fossils differing from the Meadfoot 

 beds, notably spined Homalonoti. Moreover, we have a mass of rocks 

 from which it may be safely asserted that not a decent roofing-slate 

 could be obtained. 



In the latter, namely, the slaty district of Staverton, "Woodland, 

 etc., several slate quarries are worked, and there is apparently an utter 

 absence of grit bands— I know of none. In fact the difference is, to 

 my mind, so complete as to lead to the conclusion that, from the 

 "West of the Ogwell, Ipplepen, and Dartington limestones to the 

 extreme North of the county, the Torquay grits nowhere reappear 

 at the surface. 



This formerly presented a difficulty to my mind, at least whilst 

 acquiescing in a downward sequence frem the Ogwell limestone to 

 the Culm-measure fault ; but after having convinced myself that the 

 Ashburton is identical with the Ogwell limestone, and consequently 

 that this downward sequence is illusory, and further, that the Lower 

 Devonian is on all sides faulted through the Torquay limestones, the 

 difficulty has disappeared. 



A suite of fossils, collected from several slaty localities West and 

 South-west of Totnes, to which I hope some day to draw attention, 

 will go far towards confirming the view that a large portion of the 

 South Devon slates must be classed as Middle Devonian with the 

 limestones, which they both laterally replace by interdigitation, and 

 also partially underlie. In particular the slates of Englebourne 

 Quarry near Harbertonford at once recall the "Wissenbach slates, 

 with which to some extent the organic remains also correspond. 



It is worthy of remark, as distinctly bearing upon this subject, 

 that M. Dewalque, speaking of certain tints employed by H. von 

 Dechen, especially for the slates of Wissenbach, observes parentheti- 

 cally that there is a general consent now-a-days to regard them as 

 the local equivalent of the limestone of Givet (Eifler Kalk).^ The 

 writer then mentions the Lenne schists as having a special tint. If 

 we draw a line due South from Elberfeld to Bensberg, across these 

 schists, we find nothing to support the notion of a lower reef lime- 

 stone ; on the contrary the Paffrath and Eefrath series, as prolific as 

 any Middle Devonian succession, hold a position analogous to that of 

 the Ashburton limestone, the older beds resting on the younger, a 

 fact which greatly strengthens the views advocated in this paper.^ 



When we reflect that all the rocks of our peninsula are but a link 

 in a system of plications that extend through South Ireland, under 

 the South-Eastern Counties, through Belgium, the Ehine Province 

 and the Hartz ; and on the one hand, at Killarney, we have the 



^ These must not be confounded ■with the purple sandstones and slates of Cocking- 

 ton, Ockham, Beacon Hill, "Windmill Hill, Southdown Cliff, etc., etc., which are of 

 Upper Devonian age, doubtless the equivalents of the Pickwell Down sandstones of 

 North Devon. 



2 Prodrome d'une description geologique de la Belgique, 1880, p. 114. 



3 Murchison and Sedgwick, Trans. Geol. Soc. 2nd series, vol. vi. pp. 241 — 244. 



