ON THE RED-ROOK SERIES OF THE DEVON COAST-SECTION. 149 



14. The Red-Kock Series of the Devon Coast-section. By the 

 Rev. A. Irving, B.Sc, B.A., F.G.S. (Read January 11, 1888.) 



A STAY at Sidinouth during the past summer (supplemented by a 

 second visit to the county in the Christmas holidays) has afforded 

 me the long-wished-for opportunity of forming a personal acquaint- 

 ance with the Red-Rock series of the Devon region, rocks which 

 were described many years ago by Mr. Godwin- Austen * under the 

 name of New Red Sandstone, and have been more fully described 

 since by Mr. TJssher t. The paper by the latter author is of great 

 value, as it is a very mine of facts and observations. In working 

 along the coast-sections, however, I saw reasons for doubting the 

 correctness of including the whole series in the Trias, and as I went 

 on and compared what I observed with the results of the work of 

 former years ij: in the Dyas and Trias of Germany and of the 

 northern and midland counties of England, I was forced to the con- 

 clusion that in the Devon region we have those two systems re- 

 presented. 



I propose to lay before the Society in this paper an account of 

 the observations which I have made, and to state the conclusions 

 which (on comparative grounds) I have drawn from them. 



Sidmouth (East). 



(1) The escarpment of the Sid, for some 300 yards from its mouth, 

 consists of about 50 feet of thick-bedded coarse sandstones, of a 

 prevalent peppery-grey colour, in fresh sections, the general red colour 

 of their weathered surfaces being due to rain-wash from above and 

 subsequent infiltration. They exhibit magnificent current-bedding, 

 such as we commonly meet with in the Bunter. They are slightly 

 brecciated. Intercalated with these and quite subordinated to them 

 stratigraphically are current-bedded breccias in a marly matrix, the 

 contained fragments being mostly of indurated red marl. This series 

 is seen dipping east in the coast-section and passing under 



(2) A series of massive beds of sandstone of finer texture, of a 

 pale French-grey (except on their weathered exterior §), containing 

 occasional fragments of red marl from which the calcareous matter 

 has gone, and from the surfaces of which the iron has been leached 

 out, so that they have acquired a superficial tint like that of the 

 mass of the sandstone in which they are found. Only the very 

 feeblest current-bedding is seen in these sandstones. Subordinated 



* " The Geology of the South-east of Devon," Trans. Geol. Soc, vol. vi. 



t " The Triassic Rocks of Somerset and Devon," Quart. Journ. Geol. Soc. 

 November 1876. 



i Vide Geol. Mag. dec. ii. vol. ix. (1882), dec. iii. vol. i. (July 1884) ; Quart. 

 Journ. Geol. Soc. November 1876, ihid. August 1884; Proc. Geol. Assoc, 

 vol. iv. "Notes on the G-eology of the Nottingham District." 



§ The irony colouring-matter has penetrated in some cases to a depth of 

 3 or 4 inches. 



