O. W. Lamplugh — The Bridlington Shell-heel, etc. 535 



11. — On the Bridlington and Dimlington Glacial Shp^ll-bkds. 

 By G. "W. Lamplugh. 

 (PLATE VIII. p. 537.) 

 A paper read before the British Association at York, Sept. 1881. 



THE wooden defences whicli protected the cliff opposite the 

 Alexandra Hotel at Bridlington Quay having been removed 

 last autumn, preparatory to the erection of a more substantial 

 concrete wall, a section was, for a short time, exposed which had 

 long been hidden (see section PI. VIII. p. 537). The length of this 

 section was a little over 1,000 feet, extending from Sands Cut to 

 Carr Lane ; its average height was about 30 feet. 



For the northern two-thirds of its length, this section showed 

 Purple Boulder-clay (No. 3 of section) overlaid by chalky gravel 

 (No. 2) ; and above the gravel a shelly fresh-water marl, appa- 

 rently quite recent (No. 1). The Boulder-clay and gravel were 

 very curiously intermingled, detached masses and long tapering 

 tongues of clay (in many places showing slickensides) extending 

 far into the crushed and contorted gravels. 



In this part, of the section, it seemed to me that two gravels of 

 different ages, the uppermost, probably of fresh- water origin, were 

 mingled with the remains of a once-dividing clay-band ; for, in the 

 cliff two hundred yards further north, a thin Boulder-clay, much 

 torn and dragged in its upper part, and in one or two places quite 

 cut through, is still seen between two similar gravels.^ But, as di'ain- 

 age works, which will doubtless yield fresh evidence, are now being 

 carried on in the town, I will reserve, for the present, any further 

 account of these beds.^ 



Below the Purple Clay in the southern third of the section, about 

 twelve feet of a Lower Boulder-clay was seen (No. 4), which cor- 

 responded to the " Basement Clay " of Messrs. Wood and Eome.^ 

 This clay, which was very distinct from the Purple Clay in colour 

 and character, was of a hard sandy nature and dark greenish-blue 

 colour. Boulders were neither plentiful nor large in it, but the 

 majority were far- travelled. Carboniferous rocks and Whin were far 

 rarer than in the Purple Clay, whilst in their place were a great 

 variety of igneous and metamorphic rocks — all quite unknown to 

 me — with many black flints which do not seen to have come from 

 any chalk now seen in Yorkshire. A few of these flints were green- 

 coated. 



If Scandinavian or other foreign rocks be sought for in East York- 

 shire, I think the exposures of this clay on the beach either at Brid- 

 lington or Dimlington form by far the most promising grounds for 

 exploration. 



This Boulder-clay also contained several masses of included 

 material differing from itself; and in these included masses were 

 many shells, both broken and unbroken, of species which showed 



1 For a section of this part of the clifi:, showing the two gravels, see Geol. Mas. 

 Sept. 1879, p. 393. 

 ^ For later account of these beds see forthcoming Proc. Yorkshire Geol. Soc. 1881 . 

 ^ Quart. Journ. Geol. Soc. vol. xxiv. p. 147. 



