GEOLOGY 



It has been surmised that the buried Coal Measures may extend beneath 

 some portion of the county, but the factors bearing on the question are 

 so complex and the evidence at present in hand so scanty, that further 

 deep boring can alone give proof or disproof to the supposition. 



Since the Richmond and Streatham borings are as yet the only 

 instances in Surrey where rocks older than the Jurassic have been pierced, 

 it is the more unfortunate that doubt should exist as to the age of these 

 rocks in both places. No fossils were obtained from them in either case, 

 so that we have only their general aspect on which to base an opinion, 

 and this is not sufficiently distinctive to determine the point with any 

 certainty. By some geologists they are thought to belong to the New 

 Red or Triassic system that is to say, to a system newer than the Coal 

 Measures : while other geologists have inclined to the view that they 

 more nearly resemble the Old Red or Devonian rocks, in which case they 

 will be older than the Coal Measures, a difference of opinion of course 

 very seriously affecting the question as to the most likely quarter in 

 which to search for Coal Measures. 



The main point has, however, been clearly established, that in the 

 northern part of Surrey rocks unconformably underlying the Jurassics are 

 within comparatively easy reach of exploration by borings ; and such 

 exploration, at some time or other, will no doubt be undertaken. 

 More might be said as to the bearing of the evidence from deep borings 

 outside the county limits on the probable range of its concealed Jurassic 

 rocks, but to enter more fully into the subject would be to transgress 

 the bounds and scope of this article. 



We will now therefore ascend from the depths to follow the fortunes 

 of the land-surface after the newest of its ' solid ' strata was laid down. 



ELEVATION AND DENUDATION 



We have seen that throughout the building up of its strata the 

 area was now rising, now sinking, and probably never for long quite 

 stationary. But from the Wealden onward to the close of the Eocene 

 these movements were all of a simple character, elevating or depressing 

 the whole tract without seriously disturbing its horizontality. Some 

 slight tilting and sagging there doubtless was, by which during sub- 

 mergence the waters became relatively deeper or shallower in one place 

 than in another ; but this was never sufficiently sharp to destroy the 

 general parallelism of the successive deposits in any particular spot, or, to 

 use technical parlance, to develop strong unconformability between any 

 of the separate formations. 



But subsequently, during the Miocene Period, there came a time of 

 storm and stress in the earth's crust, which affected the British Islands in 

 common with the greater part of the European continent : a time of 

 mountain-building in some quarters, as for instance in the Alps : and of 

 great volcanic eruptions and outpourings of lava in others, as in Scotland 

 and Ireland. And during this time of disturbance the rocks of the 

 south-east of England were forced by lateral pressure into broad waves 



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