T. C. Gantrill — Coal-boring at Presteign, Radnorshire. 491 



surface along the foot of the ridge, accounts for the disappearance 

 of the Woolhope Limestone outcrop in both directions. 



Fig. 2. — Vertical section, in a north and south plane, of the upper part of the 

 Folly Farm Borehole, Presteign. L, lane ; B H, borehole ; F-F, over- 

 thrust fault ; 1, 5, and 7, Wenlock Shales ; 2, Woolhope Limestone and 

 Shales ; 3, Upper Llandovery Sandstone ; 4, supposed Archsean (Long- 

 myndian) ; 6, 12 ft. limestone-band. 



The Folly Farm boring and drift are not the first nor the only- 

 recent attempts to find coal in the Silurian rocks of Presteign. Half 

 a mile farther west, and 350 yards east of Caen Wood House, a shaft 

 was begun in 1910, in the hope, as I was informed, of finding work 

 for local labour by the setting up of a new industry. The debris 

 from the shaft consists of light-blue and grey calcareous shales and 

 mudstones. These yielded nothing but an Orthis and a few frag- 

 ments of ill-preserved graptolites, doubtfully identified by Miss Elles 

 as Monograptus dubius (Suess) or If. colonus (Barr.) ; but the evidence 

 is perhaps scarcely sufficient to confirm the suspicion that the beds 

 are Lower Ludlow. 



The operations at the Folly Farm have not added so much to our 

 knowledge of the local geology as might have been expected, but the 

 boring shows the existence along the northern foot of the ridge of at 

 least one important strike-fault, having the effect of thrusting older 



