14 DESCRIPTION OF THE STRATA. 



Perhaps it may appear most natural, in giving a description of 

 the strata, to begin at the lowest visible bed, and proceed upwards : 

 but as it is no smaU advantage, in every study, to set out with what 

 is most plain and easy, and then advance to what is more difficult 

 and obscure, it seems best, in the present instance, to commence 

 with the uppermost beds in the series, and proceed downwards. 

 Instead, therefore, of conducting the reader from the Tees to the 

 Humber, we propose to reverse the order; and, commencing with 

 the alluvium, which alone is visible in Holderness, advance north- 

 ward to the chalk of Flamborough, and from thence along the coast 

 to the great bed of aluminous schistus, and the rocks that are found 

 near the banks of the Tees in the plain of Cleveland. 



We begin then with 



THE ALLUVIAL COVERING. 



It may be deemed improper to rank the alluvium among the 

 strata, as it is not, properly speaking, a pai't of the series, but a 

 covering spread over the whole; not only lying over the chalk, in the- 

 southern part of the district, but lying over each of the rocks that 

 successively i-ise up behind it, and filling up the intervals where they 

 are interrupted, or sunk down. But, as it constitutes so large a por- 

 tion of our sea-clifFs, as there is so much of our district where nothing 

 else appears above the level of the sea, and as its materials and con- 

 tents are not vminteresting, it ought not to pass unnoticed ; especially 

 as some of the beds of which it is composed, present in many places 

 the appearance of stratification, and are considered by some as really 

 stratified. 



By inspecting the Map, and the Section of the Coast, the reader 

 may perceive, that the whole southern part of our district is an 

 alluvial tract, where no rock is to be seen. This tract comprises 



