WORK ON THE PAL/EOZOIC ROCKS. 105 



prove the non-existence of coal-fields in the London basin, 

 but merely of a pre-carboniferous region analogous to that 

 separating the South Welsh and Forest of Dean coal-fields, 

 or those of Gloucestershire and North Somerset. The 

 Culford shale seemed to him probably of Silurian age. 

 Professor Judd was not sure that the beds occurring at the 

 bottom of the Richmond boring might not be abnormal 

 carboniferous rocks, like those of the Northampton borings. 

 The late president of the Geological Society, in the annual 

 address, alluded to in my last article (19), gives a summary 

 of our knowledge of the carboniferous rocks of the Dover 

 boring, and remarks that " although the prospects of finding- 

 coal in the East Anglian Palaeozoic area are not very bright, 

 it is just possible that the adventurers may strike the coal 

 measures in one or other of the narrow synclinal troughs 

 running east and west in Essex, Suffolk and Nortolk ". 

 He himself is "disposed to agree with Mr. Brady that, in 

 further explorations for coal beneath the secondary rocks, 

 the southern alternative of Prestwich is the one which holds 

 out the greatest hopes. It will be tolerably safe to assume 

 that future operations should follow a nearly direct westerly 

 course from Dover towards Bristol." 



A few observations on the general question of the dis- 

 covery of coal-fields in South-eastern England may not be 

 out of place here. 



The symmetry of the North of England coal-fields is very 

 marked, though modified by a slight circumstance which pro- 

 duces a considerable deviation from true symmetry. The in- 

 tersection of the Pennine anticline and Rossendale anticline 

 nearly at right angles to one another produces a cruciform 

 arrangement of coal-basins. On the east of the Pennines we 

 have the Northumberland and Durham and the Yorks, Derby 

 and Notts coal-fields, and on the west the Whitehaven and 

 the South Lancashire and North Staffordshire. The dome 

 of old rocks of the Lake district destroys the symmetry by 

 an extensive modification of the Whitehaven coal-field, 

 though the modification is perhaps not so marked as it 

 appears, for these coal measures probably occupy a con- 

 siderable area below the newer rocks of the Eden Valley. 



