202 Relations of the Rlicetic Beds in Somersetshire. 



period, continued uninterruptedly into the Liassic and Oolitic stages. 

 The Eh^tic beds may therefore be regarded as equal in importance, 

 geologically speaking, as any of the three divisions of the Lias or of 

 the subdivisions of the Oolites. Economically, the mapping of these 

 beds has the same value. They seldom occupy a large superficial 

 area at their outcrop, as they are generally exposed on the slopes of 

 Liassic escarpments, the New Eed Marl appearing along the base, 

 and its junction with the grey marls of the Ehsetic series being 

 often plainly seen at long distances. Their agricultural character 

 is, therefore, more or less peculiar, and whilst the Eed Marl is 

 dug for manure, the White Lias is largely used in the construction 

 of walls, and for road-mending; whilst the Lower Lias limestones 

 are used for building and paving purposes, and are extensively burnt 

 for lime. 



As Mr. Etheridge has remarked,^ if our views were based upon 

 purely stratigraphical and petrological conditions, we should assign 

 no independent position to tlie Eh^tic beds, for they indicate a 

 gradual change of physical conditions, necessarily marked by 

 palaeontological differences. 



Finding, as we do at Queen Camel, in the sections near Watchet 

 and other places in Somersetshire, such a complete passage between 

 the Keuper and Liassic beds, with about 100 feet for the thickness 

 of the intervening Ehsetic series, we cannot say that in them we 

 have a complete representation of all the beds of the great Eheetic 

 formation of South Europe. In different areas the changes would 

 not be contemporaneous, and even in the British area we should not 

 be surprised to find that Ehsetic conditions prevailed longer in one 

 part than another. 



In conclusion, we may mention that our object has been to discuss 

 certain local features connected with the relations of the Ehsetic 

 beds, to show that we have no evidences of any unconformability in 

 Somersetshire, and that such observations agree with the opinion 

 which is rapidly gaining ground, that in them we have true passage- 

 beds between the Lower Lias and Keuper formations, graduating 

 more or less imperceptibly from the one into the other, the lowest 

 members being more nearly allied lithologically and palaeonto- 

 logically to the Keuper, the upper members being similarly allied 

 to the Lower Lias. Thus the Ehsetic beds form a connecting linTc 

 between the " Oolitic or Jurassic," and the " New Eed Sandstone or 

 Triassic" systems.^ 



1 Proc. Cotteswold Nat. Field Club for 1864, vol. iii., p. 220. 



2 I would urge that a uniform system be adopted in our classification of strata. 

 By placing the Ehsetic beds as a separate period, we give the beds an importance 

 which they certainly do not possess in this country ; and therefore it seems better to 

 include them in the Trias, mainly as a matter of convenience, as such an arrangement 

 is now adopted by the highest authorities. Vide Jukes and Geikie, Manual of Geology. 

 Account of Ehsetic Beds, p. 613, by H. W. Bristow. Hull, Memoir on the Triassic 

 and Permian Eocks of the Midland Counties of England. Phillips, Geology of 

 Oxford and the Valley of the Thames, p. 101.— H. B. W. 



