Vol. 6S.l^ ANNIYERSAEY ABDRESS OF THE PEESIDEjSTT. IxXXV 



Mesozoic strata found by the borings at Battle and Burford, 

 and the exceptional thinness of the same strata more recently 

 demonstrated at Calvert. 



An exhaustive study of problems relating to cover has been 

 recently published by Mr. Lamplugh and Dr. Kitchin in a Memoir 

 of the Geological Survey dealing vi^ith the Mesozoic rocks as revealed 

 by certain of the coal explorations in Kent. This work is a very 

 valuable example, as showing how much evidence on tectonic 

 questions can be obtained from the thorough examination of the 

 lithology and palaeontology of specimens obtained from a compara- 

 tively small series of borings. 



With regard to the large-scale structure of the buried part of 

 Palaeozoic England, it might perhaps be reasonably expected that 

 some accepted general scheme of the tectonic arrangement of the 

 exposed Palaeozoic area would by this time have been evolved, which 

 would give us the means of predicting to some extent what is 

 likely to occur under the covered area. A great deal has been done 

 in this direction; but it must be frankly conceded that the tectonic 

 plan of the exposed Palaeozoic rocks of Britain is so complicated, 

 that the laws hitherto formulated do not empower us to forecast 

 the structure in disconnected areas buried under the Neozoic rocks 

 and situated far from the margin of the Triassic outcrop. The 

 movements within the solid framework of the earth appear to be 

 as subtle and complex as are the movements of the hydrosphere or 

 the atmosphere upon its surface, and they are even more elusive 

 when an attempt is made to formulate them into general laws. 



It is true that geologists are daily increasing our knowledge of 

 tectonic principles, and these principles are certain to add to our 

 power of suggesting possibilities and probabilities with regard to 

 the deeper strata. 



The structure of the Pennine anticline and its accompanying- 

 troughs, broken bj^ cross-folds into basins, is comparatively simple 

 in the exposed area ; but, when partly hidden under the Trias of the 

 Midlands, it at once takes on complications. Again, the Wealden 

 Anticline and the Palaeozoic structures hidden beneath it are 

 at present too insufficiently known to admit of any simple ex- 

 pression. And in the case of the minor folds of which these 

 grand arches are composed the difficulties are correspondingly 

 increased. 



With regard to the intimate structure of those portions of the 

 Palaeozoic floor which are made of Carboniferous rock, the structure 

 of the exposed coalfields makes it quite evident that the structure of 



