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successively terminated in a thin edge. During the convulsions which 

 threw the strata into their present form, these thin edges, being the 

 most vulnerable parts of the strata, would be most liable to be 

 shattered to pieces and washed away ; especially where the softer 

 strata, such as the chalk, the shales, and the red marl, were thus 

 exposed. Accordingly, the greatest denudations have taken place, 

 behind the chalk and the vipper shale, in the south part of our district; 

 and in the region of the alum shale and the red marl, in the north part. 

 9. Hence it appears, that we are not to expect in other parts of 

 Britain, the same series of strata as are found in our district; much 

 less can we presume, that the same series may be traced round the 

 globe. — Attempts have been made, to arrange all the beds composing 

 the crust of our globe into a complete series, exhibiting the order in 

 which, with a few variations, the strata have been deposited, and 

 may be expected to occur. Such attempts, however, have failed in 

 establishing any precise order observed by the strata; they have only 

 succeeded in tracing, in many instances, a considerable analogy, be- 

 tween the series occurring in different places. From the extent of the 

 chalk, the oolite, and a few other rocks, we may infer, that the de- 

 position of these strata has taken place on a grand scale ; but neither 

 these, nor the strata associated with them, have been deposited 

 according to fixed laws, in respect of extent, succession, or relative 

 position. One stratum wedges out in one place, and another in another ; 

 and the series rarely continues the same to the extent of fifty or sixty 

 miles. Could we penetrate the strata at Whitby, so as to ascertain 

 what rocks are under the aluminous beds, it is by no means certain, 

 that we should fall in with the series of Durham and Northumberland ; 

 and we know, that some important members of our series have not 

 been met with beyond the Humber; as, on the other hand, beds that 

 lie under the chalk in the south of England, have no place here. No 

 beds have hitherto been discovered in any other district, corresponding 



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