PRESIDENTIAL ADDRESS. 387 



additional evidence to show that before Middle Coal Measure time, denuded 

 folds, with a north-west or Charnian trend, and other folds with a north-east 

 or Caledonian trend prevailed. The post- Carboniferous and pre-Permian move- 

 ments emphasised and enlarged some of these folds. As already remarked, a 

 matter of great practical importance is as to how far these pre-Coal Measure 

 folds interfered with the continuity of deposition of the productive series, with, 

 for example, the original extension of the Thick Coal of South Staffordshire. 

 Since Jukes' time it has been known that the Thick Coal group as a whole 

 thins, and the coal itself deteriorates, southward towards the Clent and Lickey 

 Hills. It is the discontinuity and local deterioration in an east and west 

 direction, beyond the Boundary Faults, due to pre-Coal Measure flexures, and 

 irrespective of post-Carboniferous movement, that I have been emphasising. 



The powerful disturbances of post-Carboniferous and pre-Permian age, 

 which have affected all our coalfields, I have no intention of discussing here. 

 Professor Stainier, the Belgian geologist, has just published a lengthy and 

 able discussion of the subject,"^' while the lucid account by Dr. Strahan in his 

 Presidential Address in 1904 and hie recently summarised views in a lecture 

 to the Royal Institution will be in the minds of all geologists. 



I do not think, however, that it is generally realised -what a great part 

 the two dominant pre-Carboniferous systems of folding played in determining 

 the trend of the post-Carboniferoue flexures. In the South Pennines, in the 

 Apedale disturbance of North Staffordshire and in the INIalverns we have 

 nearly north and south folds due to a great easterly thrust; but elsewhere 

 in the Midlands and the North the movements were taken up, to the west 

 of these north and south lines by the Caledonian folds, and to the east 

 by the Charnian flexures. It is very instructive to watch in the centre of the 

 South Staffordshire Coalfield the old Charnian fold of Silurian rocks that 

 make up Dudley Castle Hill, the Wren's Nest and Sedgley Hill struggling, 

 as it were, against the newer post-Carboniferous easterly squeeze, -which has 

 impressed a north and south strike upon each of the domes, arranging them 

 en cclielon from north-west to south-east, and incidentally permitting the great 

 laccolitic intrusion of Rowley Regis. 



It will be found, however, that the vast majority of the folds and faults 

 in the Midland and Northern Coalfields are not along what may be called 

 strict Hercynian lines— that is, north to south and east to west — but along 

 the locally older Caledonian and Charnian directions. It was as if the great 

 north and south flexures of the Southern Pennines and Malverns, and the 

 east and west Armorican folds of the South of England, to a large extent 

 exhausted the mighty attack of the Hercynian movements coming from the 

 South and East of Europe; -while smaller intervening and relatively sheltered 

 areas were allowed to yield along their old north-west and north-east lines. 



Need for Systematic Survey by Deej) Borings. 



After all, when vie turn our attention to the possible extension of the 

 Coal Measures under the newer etrata of South-Central England, the geological 

 data at our disposal are lamentably and surprisingly few. Notwithstanding 

 our eagerness to unravel the difficulties, and so to open up new fields for 

 mining activity, very little positive progress has been made in the last twenty 

 years. Of late a few deep borings have been sunk ; one near High Wycombe, 

 after piercing the Mesozoic cover, ended in Ludlow rocks ; another at Batsford 

 in Gloucestershire, fifteen miles north of the well-known Burford boring, struck 

 •what are regarded as Upper Coal Measures, also resting on Silurian rocks. 



At the present time it seems specially fitting to call attention once again 

 to our haphazard method of grappling with this great economic question. 

 Are we to go on indefinitely pursuing what is almost ' wild-cat ' bormg, 

 to use the petroleum miner's expressive slang? Or shall we boldly face 

 the fact that systematic exploration is demanded ; and that this pioneer work 

 is a national obligation, the expense of which should be a national charge? 



At the meeting of the Organising Committee of Section C, already referred 

 to, a recommendation was forwarded to the Council in the following terms ;— 



= ' Trans. Inst. Min. Eng., vol. li., Part I., 1916. pp. 99-153. 



c c 2 



