1S25.] Diluvial FormatioHs. 25 



appearing to throw light upon its history. In many places 

 where it occupies a succession of lofty clins, it puts on a rude 

 appearance of stratification, or at least may be subdivided into 

 separate masses which possess distinct characters. 



The lower part of the cliffs, to the height of about twenty 

 feet, generally consists of a stiff bluish clay, which in many 

 places passes into a dark brown coloured loam.''^ Through the 

 whole of this mass are imbedded an incredible number of smooth 

 round blocks of granite, gneiss, greenstone, mica slate, &,c. &c. 

 resembling none of the rocks of England, but resembhng speci- 

 mens derived from various parts of the great Scandinavian 

 chain. Irregularly mixed with the preceding are found, in per- 

 haps still greater abundance, fragments of carboniferous lime- 

 stone, of millstone grit, of lias, of oolite, and of chalk, torn up 

 from the regular strata of the country, and driven into their 

 present situation by a great eastern current which has left its 

 traces on every part of the neighbouring district. In regard to 

 the imbedded fragments above-mentioned, two things appear to 

 deserve notice. 1 . They exist in equal abundance in the upper 

 as well as in the lower portions of the diluvial loam. This fact, 

 though difficult of explanation, has been remarked in other simi- 

 lar deposits, and seems to prove the gigantic nature of the 

 forces by which the materials have been drifted into their 

 present position. 2. The bowlders derived from distant coun- 

 tries are rounded by attrition; but those which are derived from 

 neighbouring rocks are little altered in form. The hard Norwe- 

 gian rocks are smooth and spheroidal, but the fragments of 

 oolite and lias, and still more the fragments of chalk, are often 

 sharp and angular. 



Over the preceding deposit come a set of beds of sand and 

 comminuted gravel, very variable both in their structure and in 

 their thickness. They seem to have been formed by a longer 

 continued and a less violent action than that which produced 

 the diluvial loam on w^hich they rest.f 



Over the sand and gravel we may sometimes find traces of 

 ancient turf-bogs and of other alluvial deposits, formed in situa- 

 tions which were once in the interior of the country ; but are 

 brought into their present position by the encroachments of the 

 coast. 



• Large grinders of the mammoth have been found in several parts of this deposit. 



-f- Near Bridlington there is a diluvial covering about sixty feet thick where we may 

 observe, 1. The clay and loam with large imbedded fragments; '2. The sand and fine 

 gravel ; 3. Over the two preceding, and immediately under the vegetable soil, a bed 

 composed of rolled fragments of chalk and of chalk flints ; in some places cemented toge- 

 ther so as to form a hard conglomerate. This bed is diluvial, and must be ascribed to 

 the last action of the retiring waters. It may be traced to a considerable height on some 

 parts of the downs when it rests immediately on the chalk ; and following the inclinatioa 

 of the ground, it descends towards, and at length covers, the ordinary diluvial deposit! 

 abovementioned. 



