Natural History. 95 



There are two Boulder Clays in the cliff between Ferriby 

 Chalk Pit and the Hall. The lower one, which is only a thin 

 deposit, is of a dark colour, is very compact, and contains a 

 fair quantity of boulders of different sorts, including rhomb- 

 porphyry and others of Scandinavian origin. * The upper 

 clay, however, is of a totally different character. It attains a 

 thickness of about 20 feet in its highest part, which is near the 

 centre of the cliffs, and gradually thins out towards the east 

 and west. It resembles the ' Hessle ' clay of Wood and 

 Rome,t being of a very red colour, blue-jointed in places, and 

 containing only a few pebbles (including rhomb-porphyry). 

 Large boulders are only rarely found in this upper clay. In 

 both deposits pebbles, generally of carboniferous limestone, are 

 often found beautifully ice-scratched, and sometimes even 

 polished. 



On the opposite side of the Humber, at North Ferriby, is a 

 precisely similar deposit, about the same size as the bed at 

 South Ferriby, containing similar boulders (though in far 

 greater number and variety), and composed of similar beds of 

 Boulder Clay, etc. These sections have recently been fully 

 described by Mr. J. W. Stather, F.G.S. I Both Mr. Stather 

 and the writer have found boulders of Shap Granite here. 



The Rev. W. Tuckwell tells me he has lately found a block 

 of Shap Granite measuring I foot by I foot, by I foot 6 inches, 

 at Irby, near Laceby, North Lincolnshire. It was c taken out 

 of an old Saxon wall,' and is 'hollowed into quern-like 

 depressions on three sides.' Of course there is no knowing 

 from where this boulder may have been carted, along with 

 other stones, to build the wall with. 



Later still, Mr. J. H. Cooke, B.Sc., F.G.S., has found two 

 or three boulders of this Granite at Goxhill. 



Mr. Clement Reid, F.G.S., in his c Geology of Holderness,' 

 1885, page 35, refers to a boulder of Shap Granite which he 

 found on the beach near Dimlington, and which up to that 

 time was 'the furthest point to the south-east to which Shap 

 Granite had yet been traced.' Later, Mr. John Cordeaux 



* For a list of the various rocks of Scandinavian origin found in Lincolnshire, see 

 the list which accompanies my paper ' On the Occurrence of Scandinavian boulders 

 in England" (Glac. Mag., vol. iii., 1895, p. 129). 



f Quart. Journ. Geol. Soc., vol. xxiv., p. 146. 



| In a paper read to the Yorks. Geol. Soc. at Whitby, July, 1896. 



ist Rept. Line. Boulder Committee, Naturalist for November, 1896. 



