WOOD AND ROME LINCOLNSHIRE AND S.E. YORKSHIRE. 183 



feet, passing through gravel all the way (the upper 60 feet yielding 

 small shells) ; this would, if the boring be reliable, seem to show 

 that the trough containing the fluviatile fossiliferous gravel of that 

 place (/in fig. 1) descends to that depth, cutting through the Gla- 

 cial clay for some distance into the chalk. A boring at Ilise, five 

 miles south-west of Hornsea, reached the chalk at 128 feet, which, 

 by deducting the elevation given on the Ordnance map for Rise, would 

 show the chalk at that place to be at about the same depth as at 

 Hornsea. From Hornsea towards Bridlington a gradual rise in the 

 chalk-floor probably takes place, accompanied by a thinning-off of the 

 basement clay and an overlap of the purple clay, since, north of Atwick, 

 the basement clay, notwithstanding the rise of the floor, is no more 

 seen. The boring at Bridlington Harbour, given by Young and Bird, 

 showed the chalk at a depth of 43 feet, the upper 28 of which was 

 occupied by clay, and the rest by a bed of gravel resting on the 

 chalk. There can, we think, be no question that this 28 feet of clay 

 is part of the purple clay, and the gravel the bed b of the coast- 

 section (fig. 1), since the purple clay shows itself resting on the chalk 

 as the latter gradually rises above the beach north of the harbour. 

 The so-called Crag having been found, and still occasionally being 

 exposed, at the beach-line, it is necessarily superior to this 43 feet 

 of deposits. 



Although the borings at Hull, Grimsby, Cleethorpe, and Bridlington 

 disclose a bed of sand and gravel between the purple clay and the 

 chalk (answering, as it seems to us, to the bed h of fig. 1), none of 

 the borings through the basement clay show anything between that 

 deposit and the chalk, except one (out of three) at Hornsea, which 

 showed 5 feet of sand beneath it. There is nothing, therefore, yet 

 disclosed in Holderness which we could refer to any older deposits 

 than the Upper Glacial clay ; and nothing that would answer to the 

 extensive Middle Glacial sand and gravel formation which underlies 

 so much of the Upper Glacial clay of the counties of Leicester, 

 Buckingham, Hertford, Essex, Suffolk, and Norfolk. 



The result of the Grimsby-Dock borings, as worked out into re- 

 sulting sections by the Dock Engineers, being referred to in the body 

 of the paper (page 157), it is unnecessary to repeat them here. They 

 showed numerous intermittent beds of gravel, answering to those 

 marked c' in fig. 1, intercalated in the purple clay, the latter some- 

 times resting directly on the chalk and being sometimes underlain by 

 gravels which seem to answer nearer to the bed h of fig. 1 than 

 to any other. No trace of the basement clay existed, although the 

 chalk was reached in many of the borings. 



At Cleethorpe, two miles from Grimsby, a boring showed 84 feet 

 of red and purple clay over the chalk (nothing like the basement 

 clay being present) ; and as the Hessle clay, 10 or 12 feet thick, 

 caps the purple clay in the cliff hard by, there is no doubt that the 

 upper 10 or 12 feet of this belonged to that clay — a sand-bed oc- 

 curred in it at far too great a depth to be referable to the Hessle 

 sand, and is therefore a similar intercalated (c') bed to those passed 

 through at Grimsby. 



