THE 



GEOLOGICAL MAGAZINE 



NEW SERIES. DECADE VI. VOL. IV. 



No. XI.— NOVEMBER, 1917. 



OIRIG-insr-A.!.. ARTICLES. 



I. — On a Boring for Coal at Presteign, Radnorshire. 



By T. C. Cantrill, B.Sc. Lond.,F.G.S., of the Geological Survey of England 



and Wales. 



IN March, 1912, a short paragraph in one of the London daily 

 papers made the astonishing announcement that several beds of 

 coal had been discovered on the Folly Farm, Presteign, and that 

 boring would be started immediately. The astonishment was due to 

 the fact that on the Geological Survey maps Presteign is represented 

 as surrounded by Silurian and Old Ped Sandstone formations, with 

 no rocks of Carboniferous age nearer than the Clee Hills, 20 miles 

 away in Shi'opshire. Unless, therefore, the Survey maps were 

 wrong, and some unsuspected outlier of Coal-measures had been 

 discovered, the name of the scene of operations was likely to prove 

 prophetic. 



While staying at Llandrindod in June following, it came to my 

 knowledge that the proposed boring had hot only been begun but 

 had already reached a depth of several hundred feet. I therefore 

 agreed to the suggestion of a resident of Llandrindod, interested in 

 the scheme, that I should take the opportunity of visiting the bore- 

 hole and reporting on its prospects. This I accordingly did on 

 July 2, 1912, and found that it had been carried down through 

 a series of mudstones, grits, and limestones, to a depth of 540 feet. 

 Silurian fossils were found to be abundant in the rocks at the surface, 

 and were present also in the cores brought up from various depths in 

 the borehole. Yet in spite of my having at once submitted a report 

 to this effect to one of the active promoters, urging him to abandon 

 the scheme, the boring was not only continued to a total depth of 

 888J feet, but was followed up by the cutting of a drift for some 

 distance into the foot of an adjacent ridge of Wenlock Shales, Wool- 

 hope Limestone, and Upper Llandovery Sandstone. 



It is scarcely necessary to say that, so far as the finding of coal is 

 concerned, all these operations were foredoomed to failure, as the 

 Silurian rocks contain no coal. 1 



The site of the boring 2 lies about 170 yards N. 17£° W. of the 



1 There is at least one simple precaution that can be taken by anyone before 

 yielding to the temptation to invest in local coal-mining ventures in districts 

 remote from the coalfields. Let an inquiry be addressed to the Geological 

 Survey Office, Jermyn Street, London. A brief, civil, and possibly useful 

 reply will be obtained at the cost of a penny stamp. 



2 The district is contained in the 1 in. Old Series Ordnance and Geological 

 Map, Sheets 56 N.E. and S.E. ; in the 1 in. New Series Sheet 180 ; and in 

 the 6 in. Map of Badnorshire, Sheet 25 (Herefordshire 10) N.E. 



DECADE VI. — VOL. IV. — NO. XI. 31 



