396 G. W. Lamplugh — The Boulder-clay at Bridlington. 



It is in the " Purple " clay that the blocks of Shap granite generally 

 occur. Though they are not often seen on the coast south of Flambro', 

 and have been supposed to be absent, 1 I noticed one lately, about a 

 mile to the south of Bridlington. It was resting on an exposure of 

 the lower part of the "Purple" clay. Its dimensions were 1^ by 1 

 by 1 feet. 



Above the top Boulder-clay, in the South Cliff, lie thick beds of 

 laminated warp and sand, mingled with, and passing into, gravel. 

 To the north of the town, these are represented by the gravels, B, 

 of the section. These warps and gravels Mr. Dakyns has recently 

 shown to be glacial. 2 They form the top of the glacial series 

 observable in the cliff sections near Bridlington. 



On the beach near Sands Cottage, a small house which stands 

 close to the cliff edge about a mile north of Bridlington Harbour, 

 the sand and shingle have, during the late stormy season, been 

 frequently swept off. On examining one of these exposures, which 

 laid bare a peculiar Boulder-clay, which I supposed at the time to 

 be part of the " Purple " clay, I came across the remnants of the 

 freshwater deposit, consisting of patches of dark silty sand, peaty 

 vegetable matter, streaks of marly clay, passing into clayey sand, 

 often stained black, and containing in places shells, sometimes 

 sparsely, and sometimes in profusion. These shells were all of one 

 species — a variety of Limncea peregra. 



These silty sands and clays were closely associated with patches 

 of gravel, generally of chalk, and sometimes ferruginous ; a few of 

 these gravel patches, however, contained scarcely any chalk, and 

 appeared to be derived from the washings of a Boulder-clay. The 

 way in which these gravels and the undoubted freshwater remains 

 were intermixed and connected, made it evident that the gravels, 

 also, were of freshwater origin. I noticed in the gravels one or 

 two large foreign blocks. 



These patches of gravels, sands and silts were seen to be con- 

 fusedly mingled with, and, in places, covered by a Boulder-clay, or 

 probably, more correctly, a till, of unusual aspect, the whole together 

 representing the top of the " Purple " clay of Mr. S. V. Wood, 3 

 which has here, as elsewhere, evidently suffered considerable 

 denudation. 



This clay however differed in appearance from the general character 

 of the Purple clay in several respects. It was not of nearly so 

 compact a nature, and where washed by the waves, became very soft 

 and unctuous, almost resembling in this the Middle Laminated clay. 

 It was also not nearly so homogeneous, being full of curious 

 patches of boulders and detritus; — here, the space of a couple of 

 square feet was covered with a mass of small angular fragments of 

 black shale ; — there, by a similar patch of well-rounded gravel, 

 entirely free from chalk ; whilst other patches of gravel consisted 

 almost altogether of chalk. Streaks of variously tinted clays, as if 

 from the grinding of some particular rock alone, were plentifully 



1 Quart. Journ. Geol. Soc. 1870, vol. xxvi. p. 90. 2 Geol. Mag. May, 1879, p. 238. 

 3 Quart. Journ. Geol. Soc. 1868, vol. xxiv. p. 149. 



