Vol. 56.] STRUCTURE OP THE MALVERN AND ABBERLEr HILLS. 167 



Coal Measures of Woodbury Hill, therefore, rest with striking un- 

 conformity upon the Silurian beds. 



The Silurian of the hills under immediate consideration includes 

 beds ranging from the Wenlock Shale to the Downton Sand- 

 stone and Ledbury Shale. The latter are followed by the Lower 

 Old Eed Sandstone, to which there is every reason to believe that 

 they are truly conformable. On the west the series is thrown into a 

 narrow overfold of Aymestry Limestone and Ludlow Shales, 

 the axis of which dips eastward, as shown by Phillips. 1 Denudation 

 of this fold has resulted in the formation of a double line of outcrop 

 of the limestone, as seen in Wallsgrove Hill and Eodge Hill. The 

 more westerly outcrop can be traced continuously from a point west 

 of Wallsgrove Farm to the extreme southern end of Eodge Hill. 

 Except in the highest parts of Eodge Hill, this band is inverted, 

 dipping, with the immediately underlying and overlying shales, 

 eastward at angles varying from 40° to 90° ; in the northern part 

 of this course the dips vary from 40° to 57° (see fig. 27, p. 174) ; 

 in the southern part, with one exception (50°), the dip varies from 

 75° to 90° (see rigs. 16-24). West of Eodge Earm the Aymestry 

 Limestone and Lower Ludlow Shale dip at 70° and 55° respectively 

 westward (see fig. 20, p. 169) ; and south-south-west of the same 

 farm the limestone has also a normal dip of 52° (see fig. 22, p. 169). 

 The Upper Ludlow rocks west of the limestone, wherever seen, have 

 similar dips. West-south-west of South wood Earm, the western 

 limit of the Upper Ludlow Shales is dislocated by a transverse fault, 

 the exact location of which is difficult. This fault is represented by 

 Phillips (op. cit. pi. ii), and also in the Geological Survey maps, as 

 crossing the whole breadth of the Silurian tract ; but I have been 

 unable to trace it beyond the Upper Ludlow Beds of Eodge Hill. 

 It seems to have resulted from a short, sharp, transverse flexure in 

 the Upper Ludlow Shales and Downton Sandstone, as represented in 

 the map (fig. 15 &, p. 164). The Downton Sandstone south of the 

 fold is much contorted and shattered. West of Eodge Earm the 

 overf olding of the upper beds is considerable, the Downton Sandstone 

 dipping into the hill at an angle of 15°, and overlying the normally 

 superjacent red Ledbury Shales (see fig. 16, p. 166). At Barrel 

 Hill Earm, beds which are apparently the red Ledbury Shales are 

 completely inverted, and underlie the Upper Ludlow Shales, the 

 Downton Sandstone being squeezed or faulted out. 



The eastern band of Aymestry Limestone has the peculiarity of 

 being squeezed or drawn out for longer or shorter distances, or 

 perhaps in some places overthrust by the shales to the east. 

 Wherever the dip can be taken it is, with one exception, easterly. 

 Eive nearly or quite disconnected portions of the limestone may be 

 seen : a very short strip crops out immediately west of Wallsgrove 

 Earm ; a longer one on the south-west ; and a still longer strip west 

 of Woodbury Hill. Immediately north of Easthope Earm the lime- 

 stone shows a subordinate overfold, the axis of which dips westward. 



1 Mem. Geol. Surv. vol. ii (1848) pt. i, p. 151. 



