384 Prof. Sedgwick on the New Red Sandstone Series in the 



Srdly, The successive deposits entering into the red sandstone series, with 

 a view to their comparison with the corresponding groups in Yorkshire and 

 Durham ; 



4thly, By way of conclusion, I shall endeavour to give a general compa- 

 rison of the red sandstone series of Scotland and England, in the hopes of 

 thereby establishing some general subdivisions, by help of which the several 

 groups may be brought into at least an approximate comparison with each 

 other. 



The details of this, and of the two other papers, will nearly define the geo- 

 graphical limits of the primary Cumbrian mountains, a general description of 

 which I hope in a short time to lay before the Society. 



§ 1 . Geographical distribution of the Red Sandstone Series, ^c. 



Between the chain of Cross Fell and the primary Cumbrian mountains the 

 red sandstone series fills a triangular area, the vertex of which may be placed 

 in one of the tributaries of the river Eden, not far from Brough, and its base 

 on the frontier of Dumfriesshire and the Solvvay Firth, Respecting the range 

 of the north-eastern side of this triangular area, I have few details to offer which 

 are worth recording ; but I may state in general terms, that if the vertex be 

 placed on the banks of the Belah (above the bridge on the road from Brough 

 to Kirkby Stephen), the boundarj/ line may thence be drawn, by Brough 

 Castle and the north-eastern side of Brough Hill, to the foot of the carboni- 

 ferous chain a little above Helton ; and that in the remaining part of its course 

 to the frontier of Scotland, it continues to skirt the chain very nearly, as is 

 represented in Mr. Greenough's map*. 



* During the summer of 1834 I examined a part of the Cross Fell chain with Mr, Bowstead, of 

 Corpus Christi College, Cambridge ; and from our joint observations, as well as from information he 

 has had the kindness to communicate, I may add the following account of the north-eastern demar- 

 cation of the new red sandstone. After skirting the north-eastern side of Brough Hill, it ranges 

 nearly in the direction of Burton; and the rock is seen, in the form of a highly calcareous conglo- 

 merate, in Walk Mill Beck, Thence the line ranges above Burton ; and skirting the hills at a con- 

 siderable elevation, passes under the base of Roman Fell (which is composed of disturbed beds of 

 old red sandstone), and is prolonged a little above Helton, and just above Murton, Beyond the last- 

 named village the line has, for a few miles, a more westerly range, so as to pass considerably below 

 Keisley ; after which it is, by a more northerly course, brought a little above the village of Dufton, 

 from which it may be traced across Swindale Beck, near the village of Knock. From this place the 

 line (still skirting the hills at a considerable elevation, though the beds of red sandstone are nearly 

 horizontal) may be traced above Milburne, Ouseby, and Melmerby ; through Raven Beck, a little 

 above Renwick ; and just above Croglin, from which place it is prolonged near the base of the 

 great carboniferous escarpment, as may be seen in numerous sections where the rocks are laid bare 



