Geology of the South-east of Devonshire 457 



Their association with the porphyry of Exeter, &c., will be noticed under the head 

 of the Igneous Rocks (postea, p. 470). 



The absence of organic remains in this deposit is very general, nor has any ex- 

 ception yet been noticed in the great mass which occurs in South Devon, though 

 it presents every variety of mineralogical character. An abundance of peroxide of 

 iron has been stated to be unfavourable to their preservation, but in many places, 

 as near Exminster, the deposit presents thick beds of yellow sands, which are 

 equally deficient in animal rehquise. The fossil castings of worms, already noticed, 

 to be seen near Sidmouth, Exeter, and other places, are the only indications that 

 animals of any sort existed ; but to this we may add, that the upper surfaces of the 

 slabs of sandstone in the cliffs west of Sidmouth present straight irregularly 

 branched bodies, and sometimes of considerable size, composed of fine-grained, 

 compact sandstone. They can be easily removed from the slab in which they lie ; 

 and if of vegetable origin, no structure is preserved, as in the fossil wood of the 

 greensand. 



Carbonaceous Deposits. (Map, PI. XLI. Sect. PI. XLIL Figs. 2, 3, 6, and 8,) 



In a communication to the Geological Section of the British Association, at the 

 Meeting in August 1836*, Prof. Sedgwick and Mr. Murchison first separated 

 from the older rocks of the West of England certain deposits which constitute an 

 extensive portion of North Devon, presenting a very peculiar mineralogical charac- 

 ter, and to which, from the abundance of terrestrial vegetation contained in a par- 

 ticular portion, they gave the name of culm deposits. In a paper I read to the 

 Geological Society in March 18361, I noticed certain conglomerate and sandstone 

 strata, exhibited in Ugbrooke Park, near Chudleigh, and other adjacent places, and 

 which I erroneously supposed to be included in the transition series. In the au- 

 tumn of the same year, I pointed out these deposits to Prof. Sedgwick, who con- 

 sidered them as a portion of the culmiferous beds of the centre of the county. 



The first point of interest connected with the carbonaceous series in South Devon 

 is the position of certain deposits in the neighbourhood of Newton Bushel, and of 

 those in Ugbrooke Park above alluded to. Rydon Hill (PI. XLIL fig. 2.), near New- 

 ton, consists, in its upper portion, of black shales and conglomerates, containing 

 much disseminated carbonaceous matter and occasional vegetable remains ; so that 

 in general aspect and character the deposit differs widely from the slate series of 

 the district. It has a very limited range, and has been accumulated on an uneven 

 and abraded surface of older rocks. Figs. 9. and 10. (see next page) represent this un- 

 conformable position as exhibited in quarries near Newton. On the right of the road 



* See Report of the British Association for 1 836, Notices of the Sectional Meetings, p. 95. 

 f See Proceedings, vol. ii. p. 414. 



