Yol. 6S.'] ARDEN SANDSTOKE GEOUP OP WAEWICKSHIRB. 269 



means of a simple character. From the sections made across the 

 district (figs. 1-6, pp. 258-59, 260) it will be seen that the Marls 

 are thrown into a number of shallow synclines and anticlines, and 

 are broken in places by faults, usually of small throw. But the 

 sandstone forms so many outcrops in this region that I have gone 

 further, and have ventured to produce a contour-map (fig. 7, p. 270) 

 showing, as nearly as I can determine it, the form of the top of the 

 Arden Sandstone Group as it would appear if the overlying Marls 

 were removed and the denuded portions of the Sandstone restored. 

 Owing to the variation of thickness in the Sandstone Group, a 

 contour-map for the base of the Sandstone would, of course, differ 

 in detail ; but in its main features it would correspond. The 

 contours are taken at intervals of 25 feet, and they bring out the 

 following points : — 



(1) The beds have been subjected to folding of a slight character in 



several directions. 



(2) The dominant strike is nearly parallel to the general trend of the 



main outcrop of the Lias ot the Midlands, that is, it is north-east 

 to south-west, or Caledonian in direction. The principal 

 direction of the dip of this area, especially the western portion, is 

 to the south-east. 



(3) But there is considerable cross -folding at a right angle to the 



Caledonian direction of movement, producing axes having a north- 

 west to south-east (or Charnian) direction. Most of the faults 

 take this trend. 



(4) Some folds have Pennine or Malvernian (north to south) axes, 



while at least one (near Henley-in-Arden) seems to have been 

 produced by a combination of the Charnian and Pennine move- 

 ments, being intermediate (north-north-west to south-south-east) in 

 direction between the two. 



(5) Owing to the south-easterly tilt, the contours do not often form 



closed curves. 



A study of a geological map will show that all these three move- 

 ments are represented in the adjoining areas. For instance, the 

 Caledonian movement determines the main boundary of the Lias 

 from Leicestershire to Warwickshire ; the Charnian is revealed by 

 several lobes of the Lias projecting from the main mass to the 

 north-west, as at Feckenham and near Leamington; while the 

 Pennine effect is well marked in the north-to-sou th faults at 

 Warwick and the trend of the western edge of the Permian country 

 of Warwickshire. 



The folding of the Upper Keuper Sandstone in South Worcester- 

 shire (Pendock district) has been described by Mr. L. Richardson, 

 who has given reasons^ for the opinion that the folding of this 

 band was initiated before the deposition of the Rhaetic. This may 

 well have been the case also in Warwickshire ; but the pre-Rhsetic 

 movement must have been slight, as tke greater part of the 

 movement is certainly post-Liassic, the Lias of the neighbourhood 

 being affected almost equally with the Keuper. 



^ Proc. Cottesw. Nat. F.-C. vol. xv (1904^1906) pp. 93-100 ; Q. J. G. S. vol. Ix 

 (1904) pp. 349-58 ; and ibid. vol. Ixi (1905) pp. 425-27. 



tj2 



