of the Parallelism of Contemporaneous Lines of Elevation. \2B 



have here again a want of exact conformity ; but the difference 

 is scarcely any where sufficient to be sensible to the eye, and 

 can only be recognised by its results on the grand scale : yet 

 these instances are sufficient to show that the elevating forceis 

 have acted somewhat differently in the oolitic and cretaceons 

 systems. In Dorsetshire, indeed, the oolites are affected by 

 considerable disturbances in the vicinity of Weymouth, but 

 these appear to have been connected with the convulsions 

 which overthrew the Isle of Wight in the tertiary period. 

 In Yorkshire, we observe on the coast a considerable dislo- 

 cation of the alum shale near Cloughton : this point is the 

 more worthy of especial notice, because it is situated in the 

 prolongation of the line of the great Cleaveland basaltic dyke, 

 which extends from the central ridge of carboniferous lime- 

 stone, and ranging nearly in an easterly direction, intersects 

 the coal-measures, new red sandstone, and even the oolites ; 

 so that this point indicates a connexion of the disturbances 

 which have here affected the oolitic system with the convul- 

 sions and basaltic dykes of the coal-field. The Northumber- 

 land coast near the mouth of the Tyne presents a still more 

 decided evidence to the same effect (so far at least as the 

 magnesian limestone is concerned); for this latter rock is here 

 thrown down by the great 90-fathom dyke, by far the most 

 important of the faults which affect the Newcastle coal-field, 

 inasmuch as it occasionally deranges the level of the strata 

 on either side of it no less than 140 fathoms. It ranges east 

 and west for about ten miles, when it crosses the Tyne; but in 

 the upper part of the valley of the South Tyne, in the prolono-a- 

 tion of this line there is an immense fault, called the Stubbick 

 dyke, operating in the same direction, which may therefore 

 be very prol)abiy considered as its continuation, and which 

 occasions a long narrow subsided strip of the upper coal-mea- 

 sures to extend transversely across nearly the whole breadth 

 of the mountain limestone chain; so that we must regard this 

 dislocation as one of the most considerable with which we are 

 acquainted. It affects the magnesian limestone not only at Cul- 

 lercoats, but seven miles further on its course at Killingworth, 

 and the same distance from any other locality to which the 

 magnesian formation now extends. The depi-ession occasioned 

 by the fault becoming here much more considerable (4.4.O fa- 

 thoms), a small portion of the lower magnesian sandstone or 

 rothetodte here becomes included, as the upper member of 

 the subsided mass of strata : — the inference is clear, that this 

 sandstone formation must at the period when this subsi- 

 dence took place have extended continuously to this point; 

 and that therefore its lemoval over a tract at least six miles 



