Vol, 68.] ANNITEESAET ADDEESS OF THE PRESIDENT. Ixxxiii 



from the mouth of the Tees to that of the Exe. More accuratel}% it 

 corresponds with the outcrop of the base of the Trias. To the north 

 and west Palaeozoic rocks outcrop at the present surface of the 

 country ; to the east and south the same rocks outcrop at some 

 depth below the surface, against the base of formations not older 

 than the Trias. The first portion has an area of roughly 2-5,000 

 and the second of 33,000 square miles, the relative proportions- 

 being 43 to 57 per cent. 



In the western and northern area, thanks to the labours of the 

 Geological Survey, we possess maps which not only indicate the- 

 proportion of the whole area occupied by the outcrop of rocks of the 

 various Palaeozoic systems, but also afford a fair general knowledge- 

 of the folding and faulting to which the rocks have been subjected. 



In the Sub-Triassic eastern and southern area, however, excellent 

 as are the Survey Maps of the surface outcrops of the Neozoic- 

 rocks, our knowledge of the concealed outcrop (or incrop as it may 

 be called) of the Paloeozoic rocks, owing to the blanketing of that 

 incrop by the overlying formations, is exceedingly limited — indeed,, 

 over a considerable part of the region it amounts to practically 

 nothing. And yet it is in this area alone that we have 

 any chance of finding new coalfields. 



The total area of the exposed coalfields of England and 

 Wales, including only those in which measures bearing workable- 

 coal are known to occur, is approximately 3000 squares miles, as 

 deduced from the figures given by Professor Hull in his work 

 on 'The Coalfields of Great Britain.' This amounts to about a 

 twentieth part of the whole area of the two countries. But the 

 comparative richness of our land in mineral fuel is made clear 

 when it is remembered that the fields referred to are those only 

 wliich occur outside the Triassic outcrop, and that the proportion 

 of uncovered Coal-measure outcrop to the area of the PalcTozoic 

 rocks, as a whole, is just under an eighth, or 12 per cent. 



If, now, we make the assumption, not altogether an unreasonable 

 one, that the structure of the hidden Palaeozoic floor within the 

 boundary of the Trias outcrop is roughly comparable with that of 

 the visible Palaeozoic floor outside of it, there is at least a chance 

 that the incrop of Coal-measures existent below the area occupied 

 at the surface by Neozoic Formations may amount to an eighth of 

 that area — that is to say, approximately 4000 square miles. 



It may be urged that the effect of the repetition due to the 

 Pennine fold has been to give to the uncovered Palaeozoic region an 

 unduly large area of Coal-measures within a depth easily worked,, 



