168 DESCRIPTION OF THE STRATA. 



thickness at Craniraoor, and which sink under the north skirts of the 

 Hambleton hills at Thimbleby, make a bend upwards, and run to a 

 tliin edge, on the borders of that plain, so as to allow the red sand- 

 stone to succeed them there; or else, that the red sandstone does 

 not lie under the aluminous strata, as the next succeeding member 

 of the series, but merely abuts against the broken edges, both of 

 these strata, and of the strata over them, occupying the valleys in 

 the form of what has been called an upfilling. It is certain, that the 

 red sandstone appears in the latter form in several parts of England ; 

 particularly in the extensive plain, in which Appleby, Penrith, and 

 Carlisle are situated ; and in the vale of the Avon, near Bristol :* 

 and it is not unlikely, that our red rock may be in the same predica- 

 ment. It has not been found under our aluminous strata; nor, as far 

 as we know, has it been seen over the magnesian limestone, which 

 commences at Hartlepool. Besides, its position has no conformity, 

 eitlier with the one or the other ; for the beds observed in Cleveland, 

 instead of dipping towards the alum hills, so as to appear to run 

 beneath them, rather dip in the contrary direction ; and where the 

 sandstone makes the nearest visible approach to the magnesian lime- 

 stone, near the entrance of Hartlepool harbour, both are dipping 

 towards one another, the limestone dipping towards the south, and 

 the red sandstone towards the north ; so that we may suppose them 

 to meet each other abruptly under water, at the entrance of the har* 

 bour. It is obvious, however, that great dislocations of the strata 

 have occurred at Hartlepool harbour, as at that of Whitby, the Slake 

 appearing to be another centre of subsidence ; and for this reason, 

 and the entire concealment of the junction between the red rock and 

 the strata adjoining it, both on the south and on the north, we cannot 

 .speak on this point with certainty. Should it be found, that the red, 



* Geological Transactions, IV. p. 105, &c.j and p. 193-196, 205-209. 



