544 TRANSACTIONS OF SECTION C. 



The same idea of a moderate degree of submergence, .icconipaniecl by 

 temperate conditions of climate has been applied by Mr. Clement Reid ' to 

 the shelly gravels of Holderness. Mr. Reid has also proposed to include the 

 buried cliff-beds of Sewerby in the same interglacial stage ; but as the gravels 

 rise to nearly 100 feet above the level of the old beach in northern Holderness^ 

 and are separated from it by the Basement boulder-clay, I am sure that this 

 correlation cannot be sustained. 



These Holderness gravels are supposed to be absent from the coast sections, 

 and it is suggested that they may lie below sea-level in this quarter; but this is 

 not very probable, as they are found at an elevation of 50 feet within a few 

 miles of the coast in southern Holderness, and the Basement boulder-clay rises 

 well above sea-level in the cliflfs at Dimlington. It is true that the gravels of 

 the coast sections afford no support to the idea of a mild interglacial sub- 

 mergence, and are evidently of similar origin with the rest of the glacial deposits, 

 but I can see no other reason against their correlation with the gravels of the 

 neighbouring interior. Except in two or three limited tracts, the shells in the 

 Holderness gravels are as fragmentary, and nearly as scanty, as in the mouudy 

 gravels of Flamborough Head, which from their character and position cannot 

 be of marine origin. Even at the exceptional places referred to, where the 

 fossils are more plentiful, there is a mixture of forms, including an abundance of 

 the freshwater shell Corbicula Jluminalis, which seems to denote their derivation 

 from pre-existing local deposits ; and in the new section at Burstwick, described 

 by Mr. T. Sbeppard,* these shelly gravels revealed the same close association with 

 the boulder-clay that is so frequently displayed in the glacial gravels of the coast 

 sections. 



The Kirmingtoii Section. — There is, however, one case known to me in the 

 3ast of England, and only one, in which an undoubtedly contemporaneous fauna 

 occurs in beds intercalated with the boulder-clay series.^ At Kirmington, in North 

 Lincolnshire, a brickyard is worked in a deposit of estuarine clay lying in the 

 middLe of a broad shallow valley which cuts across the Chalk Wolds about eight 

 miles south of the Humber. Recent investigation by a Research Committee of 

 the Association, in which I took an active share, has shown, somewhat unex- 

 pectedly, that the surface of the chalk at this place descends to present sea-level, 

 and that the estuarine warp is underlain by over 60 feet of drift, consisting of 

 sand and chalky gravel, with two thick bands of tough clay containing far- 

 travelled stones.'* The boring in which these beds were proved was insufticient to 

 show precisely whether the stony clays possessed the distinguishing features of 

 true till, but there can be no doubt as to their glacial character, since we know of 

 no deposits of this kind in the east of England except those of glacial age. At the 

 base of the estuarine warp, at 65 feet above Ordnance datum, we found a thin 

 seam of silt and peat containing a few freshwater shells and plant remains, which, 

 like the very scanty fauna of the overlying warp, give no precise indication ol 

 climatal conditions, though suggesting that the climate was cooler than at present. 

 The estuarine bed is overlain by a coarse gravel of rolled flints, and in one part c" 

 the section this gravel is covered by 3 or 4 feet of red clay with far-travelled 

 stones, resembling the Upper boulder-clay or Hessle Clay of Holderness. The 

 character and fauna of the warp show that it must have been laid down between 

 tide-marks, and we therefore gaiu an exact measure of the sea-level at the time of 

 ita accumulation, and also, I think, of the highest limit of marine submergence in 

 this part of England during any stage of the Glacial Period. 



' ' The Geology of Holderness.' Mem. Oeol. Survey (1885). 



" ' On another Section in the so-called Interglacial Gravels of Holderness.' 

 Proc. Yorks. Geol. and Polytech. Soc., vol. xlii. (1896), pp. 1-14. 



' The freshwater deposit which I found some years ago at Bridlington, and at first 

 thought to be probably intercalated with the boulder-clay, proved on fuller exposure 

 to lie above the boulder-clay, with which it had become entangled by later dis- 

 turbance. See Oeol. Mag., dec. ii., vol. vi. (1879), p. 393 ; and Proc. Yorfts. Geol. and 

 Polytech. Soc, vol. vii. (1881), p. 389. 



* Rep. British Assoc, for 1901, pp. 272-274. 



