C. CALLAWAY ON THE QTJAKTZITES OF SHROPSHIRE. 755 



horizontal development of the quartzites. They are finely exposed 

 on the south-east side of the Wrekin range from its north-eastern 

 extremity, half a mile south of Wellington, to its south-west end, a 

 length of about three miles. The range is composed of three eleva- 

 tions, separated by two narrow gorges. The south-westerly, and 

 by far the largest, mass is the Wrekin proper, and is If- mile in 

 length. The north-easterly hill, called the Ercal, is of less height 

 than the Wrekin and of about half the length. The central hump, 

 Lawrence Hill, is still lower, and occupies about a quarter of a mile 

 of the length of the range. Throughout this paper I apply the name 

 " Wrekin " to the Wrekin proper, the " Wrekin range " including 

 also the Ercal and Lawrence Hill. This chain will be more fully 

 described in my paper on the igneous rocks of the district. The 

 quartzites rest against the volcanic axis in a nearly continuous band, 

 striking to the south-west, parallel to the axis, broken by the above- 

 named ravines, and apparently disappearing towards the summit of 

 the chain. They reappear, however, towards the south-west end, 

 and lap round the south-westerly spur of the mountain. I have 

 taken numerous dips on the flanks of the Ercal, Lawrence Hill, and 

 the Wrekin, and find that the direction of dip is on the average a 

 little to the east of south-east, and its amount about 45°, ranging 

 between 30° and 55°. Other exposures on the flanks of the range 

 are scanty. An opening west of the south-westerly spur of the 

 Wrekin shows a dip to the south-west. The inclination of the 

 quartzite in all the above cases is away from the central axis, and 

 is obviously due to its elevation. I have been unable to dis- 

 cover any exposures on the north-west side of the Wrekin. Under 

 the summit of the mountain I can detect no traces of the quartzite ; 

 and this apparent break in the continuity corresponds in position 

 with the disappearance of the rock on the opposite flank of the 

 ridge. Eurther to the north-east of this point there is clear evi- 

 dence of the quartzite in the shape of the ground, in the soil, and in 

 the character of the vegetation. It here forms a buttress to the hill. 

 The following section across the Wrekin (fig. 1) shows the position of 

 this mass and of the quartzite on the south-east side of the axis. 

 The section cuts the range at right angles at half a mile south-west 

 of the north-east end of the Wrekin mass. 



Keeping along the north-west side of the range towards the north- 

 east, we next come to a small exposure of the quartzite cut through 

 by the ravine separating the Ercal from Lawrence Hill. The sec- 

 tion is too small and obscure for satisfactory determination ; but the 

 beds are apparently nearly vertical, with a slight tendency towards 

 a south-east dip, that is, towards the axis. There is also a small 

 mass of the rock at the north-east end of the Ercal, and in a line 

 with the axis of the chain, but the dip and strike cannot be deter- 

 mined. Judging by the shape of the ground and soil indications, 

 the quartzite is probably continuous all round the Wrekin range, 

 with the possible exception of the two points under the summit on 

 each side. 



In the Wrokin-mass the quartzite does not reach the top of the 



