Rev. Dr. Irving— On the Younger Red Roclcs. 365 



English areas) being traceable to the older rocks of the region as 

 their source, in the valleys and creeks and fjords of which it was 

 deposited ; while the materials of the coarser sediments of the 

 Trias (Bunter) are of a more varied nature, including, and in some 

 localities almost entirely made up of, well-rolled detritus (often 

 containing fossils of Silurian age) derived from a wider area, and in 

 some cases transported from a considerable distance. The striking 

 contrast between the German Dyas and Trias, based on physical 

 facts alone, taken along with the stratigraphical hiatus which exists 

 between them, and the complete concordancy of the whole succession 

 of the strata which constitute the German Trias, harmonizes fully 

 with the palaaontological evidence which has been worked out so 

 thoroughly by Geinitz and others on the Continent, and by King 

 in this country. 



The Devon Area. 



With the results indicated above pretty well established and the 

 knowledge gained at first-hand of the German Rothliegendes and 

 its English representatives, it is not surprising that on my first 

 examination of the Red Eocks of the Devon Coast Section in 1887 

 I was unable to accept the mapping of them as wholly of Triassic 

 age, or the interpretation of that magnificent coast section from 

 Seaton to Torquay, which had been published by Mr. Ussher in the 

 Quart. Journ. Geol. Soc. The attempt on my part to carve out a 

 Permian system in the paper published in the Quart. Journ. Geol. 

 Soc. in 1888 was officially ignored ; but when, after some delay 

 (mainly on official grounds). Prof. Edward Hull was able to verify 

 my main contention from field-observations, a very energetic attempt 

 was made to explain it all away (see discussion of the Papers by 

 Prof. E. Hull and A. Irving in Quart. Journ. Geol. Soc. for 1892). 

 Further work in the field in the year 1892 (see Quart. Journ. Geol. 

 Soc. for February, 1893) led to the definition of the base of the 

 Keuper along the Otter Valley, as it had been previously recognised 

 in the Valley of the Sid. The surrender by Prof. Hull of the only 

 point of importance on which we had differed,' on going over the 

 ground together the year before, cleared the issues of the controversy, 

 and made a complete and direct correlation of the Devon lied Rock 

 Series (from stratigraphical and lithological evidence) with those of 

 the Midland and Severn country, and with those of Central Germany, 

 not only possible but easy. 



In my 1892 paper I dwelt upon the importance of the evidence 

 furnished by the contemporaneous volcanic rocks in the breccia- 

 sandstone series of Devon (just as they occur in the Permians of the 

 Solway Basin and of Central Germany), and on the other hand the 

 entire absence of them from the undoubted Trias of Devon (as they 

 are absent from the Trias of the two regions just mentioned). The 

 value of this comparative evidence was generally admitted in the 

 discussion of that paper at the Geological Societ3^ I felt, however, 



' That is to sav, the asje of the a^reat red marl series below the Budleigh Salterton 

 Pebble-bed. (See Q.J.G.S. vol. xlix. p. 83.) 



