OP THE N.W., midla:^d, and eastern counties. 185 



Drift-Deposits around Gainsborough, 



At Gainsborough and southward, though at no great distance from 

 the Lincolnshire chalk-wolds, I saw a clay of varying colour 

 graduating downward into the underlying marl of Triassic or sub- 

 sequent age. On the summit of the Triassic escarpment it mainly 

 consisted of directly worked-up gypseous marl, with a considerable 

 quantity of chalk debris, which, however, was nowhere thoroughly 

 incorporated with the clay itself — so little so that the greater part of 

 the clay would not effervesce with ordinary tests. The chalk was 

 not a constituent of the clay, but an addition. The clay, along with 

 the chalk erratics, contained Bunter pebbles, fragments of Carboni- 

 ferous rocks from the Pennine Hills, igneous and metamorphic rocks 

 including gneiss (from I^orway ?). It was covered with, or graduated 

 upwards into, sand, with Bunter pebbles, wholly or partly derived 

 from the clay. Between Eetford and Bawtry, as may be seen in 

 the railway-cuttings, there are beds consisting of rearranged Bunter 

 pebbles and sand, which contain a few chalk-flints, but very few 

 other erratics. This gravel-and-sand is apparently on the same 

 horizon as the Gainsborough sand, and in places is covered with a 

 clayey wash which may be a southerly attenuation of the Hessle 

 clay of Yorkshire. The underlying gravel-and-sand may represent 

 the great gravel-and-sand formation around York, under or in the 

 lower part of which comes the remarkable lenticulation of laminated 

 stoneless clay, and under this the "carrion," which is a clay or loam 

 with boulders of Millstone Grit and Mountain Limestone from the 

 Pennine Hills, and which can be traced westward through gaps in 

 these hills. Its relation to the purple-clay of East Yorkshire is still 

 uncertain*. 



Correlation of the Drift- Deposits of W. Yorkshire with those of 

 Lancashire and Cheshire. 



In 1867-70 I endeavoured to trace the connexion between these 

 deposits by way of the Aire and Wharfe valleys and the plain of 

 Craven. I was fortunate in meeting with many clear sections 

 during the drainage of towns and excavations for house-sites ; and 

 the results were very briefly stated in a paper which appeared in 

 the ' Proceedings ' of the West-Kiding Geological and Polytechnic 

 Society. Lowest of all is the blue clay, which nowhere rises higher 



* In the western part of the vale of York, Jurassic debris from the north or 

 east are associated with Millstone Grit and Mountain Limestone from the west ; 

 and Gryphites have been reported as having gone far up the valley of the Aire ; 

 but as the Rev. N. Tute found Lias fossils near Leeds, which had been brought as 

 railway ballast from the foot of the Hambleton Hills, little reliance can be placed 

 on such reports. There can, however, be no doubt that Mr. Tute found Shap 

 granite in the yellowish-brown clay which overlies the verj' dark-coloured or 

 blue clay west of Ripon. After crossing Stainraoor, the Shap granite may have 

 gone south by Richmond to the neighbourhood of Ripon. The precise position 

 of Shap bouldei-s in the drift-deposits of the east coast of Yorkshire has not, I 

 believe, been yet ascertained. Granite from the south of Scotland has been 

 found on the coast near Scarborough ; but whether it accompanied the Shap 

 grauite over Stainmoor, or went east along the upper course of the Tyue, and 

 then south-east, it might be difficult to ascertain. 



Q. J. G. S. No. 142. 



