258 MR. E. HULL ON THE NEW RED SANDSTONE, ETC., 



The formations to which these observations refer are 

 largely distributed over the Midland, Western, and North- 

 Midland counties. In geological position they are in- 

 cluded between the Coal formation below, and the Keuper, 

 which forms the upper division of the New Red Sandstone, 

 and which yields the brine-springs and rock-salt of Che- 

 shire and Worcestershire. From this formation the brine 

 at Rug])y and Cheltenham has undoubtedly been derived, 

 by ascent through the overlying Lias. Under these towns 

 the true fresh-water-bearing strata are in all probability 

 entirely absent, and will not be found south-east of a line 

 drawn from the Bristol Channel to the mouth of the 

 Humber. This is owing to the attenuation or thinning 

 out of the Triassic formations towards the south-east of 

 England — a most interesting fact in physical geology, and 

 one to which I drew attention in a paper published by the 

 Geological Society of London*. Its bearing on the ques- 

 tion of water-supply should never be lost sight of. 



These changes in the thickness and distribution of the 

 Trias and Permian beds are represented in Fig. I. It 

 will be observed that, out of five subformations resting 

 directly on each other, all except that marked 2 are water- 

 bearing; and also how these strata attain their greatest 

 vertical development in Lancashire and Cheshire, and thin 

 away in the direction of the mouth of the Thames. 



The general succession of the series is as follows : — 



New Eed 

 Sandstone " 



' 5. Upper Mottled Sandstone. — Fine soft incoherent sandstone. 

 4. Pebble-beds. — Eeddish-brown pebbly sandstone, used for 

 building, becoming a loose conglomerate in Staffordshire. 

 3. Lower Mottled Sandstone. — Fine soft incoherent sandstone. 

 Permian J 2. Eed Marls, with limestone (not water-bearing). 

 Beds I I. Lower Eed Sandstone. — Soft fine red sandstone. 



The Lower Permian sandstone, a nearly homogeneous 

 rock of extreme porosity, attains considerable thickness in 



* " On the South-easterly Attenuation of the Lower Secondary Eocks of 

 England," Quart. Journ. Geol. Soc. vol. xvi. 



