DRIFTS OF FLAMDOROUOn HEAD. 301 



by another observer be considered of less importance than otliers 

 wliich liave been passed over. 



The sections figured as illustrative of tiie beds are drawn to a true 

 scale, though sometimes sliglitly foreshortened, to bring witliin their 

 limits some feature of interest which might otherwise lie beyond 

 thera. 



At the south-western corner of the area, the sections adjoin the 

 better known sections of Holderness, and I take this for my starting 

 point in describing the beds. 



(a) Br'uUington Qaaij (PI. XIII. fig. 2). — Full descriptions, with 

 large-scale sections (GO feet to 1 inch, with enlargements of 10 feet to 

 1 inch), having already been published of the cliff's in the immediate 

 vicinity of Bridlington (iuay *, a passing reference to them will 

 suffice. These sections are now nearly all concealed by the structures 

 raised to defend the coast from the encroachments of the sea. Their 

 general character is illustrated in PI. XIII. fig. 2. The dark shelly 

 " Basement Clay " of Holderness (4 of fig. 2) is recognized between 

 high- and low-water marks south of the Harbour, and rises into 

 the cliff close to the town, probably moulded upon a chalk-ridge. 

 Half a mile farther north it reaches a height of 15 feet above high- 

 water mark (Beaconsfield Terrace), and a boring on the foreshore at 

 this place proved its total thickness to be at least 35 feet ; but north- 

 ward it sinks rapidly, and goes below high-water mark ofi" the Alex- 

 andra Hotel. 



It is where the clay is highest in the cliff that the more impor- 

 tant of the shelly patches which occur in it have been found f, these 

 being irregular masses of sand and clay, as truly " boulders " as the 

 similar mass of Lower-Lias shale observed by John Phillips J on 

 the adjoining foreshore. 



South of the Harbour the Basement Clay is overlain by finely 

 laminated gutta-percha clay of variable thickness, quite free from 

 stones or other inclusions ; but this bed disappears where the 

 Boulder-clay rises above high-water mark, reappearing, however, 

 when that bed sinks again to the shore on the north side of the 

 town (4 a of fig. 3). 



Above the laminated clay, or, where that bed is absent, directly 

 ■upon the Basement Clay, we find dark brownish Boulder-clay, with 

 intercalated gravels (3 «, 3 6, 3 c of fig. 2), evidently the same as 

 the " Purple Clays " of the Holderness sections. This clay is 

 generally divided into two parts, as in Holderness, either by the lenti- 

 cular seams of sand and gravel (3 h) or by a well-marked stratified 

 band (South Sands). It is generally possible to detect worn frag- 

 ments of marine shells in the Purple Clay, though they are very 

 much rarer and in worse preservation than in the Basement Clay. 

 Similar fragments may also often be found in the associated gravels. 



The uppermost portion of the Boulder-clay in fig. 2, though it is 

 not very distinctly separable from the '* Purple Clay," is, in every 



* ' Glacial Sections near Bridlington,' pts. i., ii., iii., & iv. op. cit. 

 + Ft^r lists of shells and other details, see papers cited above. 

 I * Geology of Yorkshire,' pt. i. 3rd ed. p. 85. 



