﻿1861.] 



PRESTWICH BOULDER-CLAY. 



447 



Hull and examined the Boulder- clay of the Yorkshire Cliffs, when 

 my attention was drawn to the single valve of a Oyrena fluminalis, 

 identical with the Grays species, in the fine collection of organic re- 

 mains of Mr. Leckenby, of Scarborough, and long known to Mr Morris. 

 Mr. Leckenby informed me that it came from the shelly gravels 

 described by Professor Phillips near Hull, where it was not rare. 



Returning to Hull and following the instructions given in Prof. 

 Phillips's * Geology of Yorkshire ' (vol. i. p. 23), I found my way 

 readily to the gravel-pit, one mile south of Bidgemont near Hedon, 

 therein described. Professor Phillips gives a list of eight shells 

 from this locality, and also notices the common occurrence of another 

 shell which he could not refer to any then described species, and 

 which proves to be this Oyrena. The section is small ; and although 

 the superposition of the beds is not shown, they are justly inferred 

 by Prof. Phillips to be closely connected with the Boulder-clay. 

 To the S.W. of this pit are several old pits, now nearly obscured, to 

 which I shall revert presently. My attention was then directed to a 

 large ballast-pit on the Hull and Holderness Bailway, one mile S.S.W. 

 from the above-mentioned pit, and 8£ miles eastward of Hull. There 

 is no name given to the spot on the Ordnance Map, but locally it is 

 known 'as " Kelsey Hill." The section at this spot is extremely in- 

 teresting. It exhibits great beds of coarse gravel and fine shingle 

 interstratified roughly and irregularly with beds of sand — the whole 

 of a light colour, and with much oblique bedding. In places there are 

 no shells ; in other places they are most abundant The following 

 sections give the general characters of the deposit. 



The gravel in the upper Section at the East End of the 

 beds consists of subangular Ballast-pit, Kelsey Hill. 



flints with pebbles of the n.b. s.w. 

 older rocks, but the latter Feet. im^ww^imga^^ a, 

 are in far larger proportion in 

 the lower part of the section, 

 some beds consisting almost 

 entirely of small boulders of 

 granite, greenstone, quartz, 

 porphyry, mica-slate, lime- 

 stones, sandstones, lias, and 

 hard chalk, together with 

 very large flints*. They are 

 almost all worn and sub- 

 angular, and many are per- 

 fectly rounded. Some spe- 

 cimens are above a foot in 

 length. A few of the lime- 

 stone blocks retain faint 

 traces of glacial scratching. 

 Many of the blocks of chalk 

 are drilled with Annelid borings and perforated with the holes of the 

 Pholas crispata. Some few of the rock-blocks and many of the large 



* See ' G-eology of Yorkshire,' 2nd edit. p. 20-23, for fuller details of the 

 lithological character of the strata. 



2h 2 



ci- Gravelly soil. 



b. Rather coarse gravel. 



c. Sand and fine gravel. 



d. Gravel composed of small rounded 

 boidders mixed with shells, 5-6 feet. 



e. Light-coloured sands, with shells, 

 chiefly in fragments. 



