1853.] 



MORRIS — LINCOLNSHIRE DRIFT. 



32} 



containing comminuted chalk and flint. Another peculiar feature of 

 interest is the occurrence of large angular masses of soft stratified 

 sand, apparently removed from an upper portion of the oolitic series 

 of the district. 



This upper division of the Drift is of somewhat lighter colour 

 than the lower, and its boulders are more numerous and larger than 

 in the latter, and the chalk detritus is more abundant, but the line 

 of separation does not appear so distinct as in that at the northern 

 end of the tunnel, as above described. At the south end of this 

 cutting the drift was observed to repose on a decomposed band of the 

 oolitic rock. 



Section 5. — As far as the Railway sections are concerned, the 

 drift is last seen in a small cutting a quarter of a mile south of the 

 last-described, but it occupies the adjacent valleys north and south 

 of this point. 



The object of this paper being simply to describe the local phse- 

 nomena of the Drift exposed by the railway cuttings, the general 

 arrangement of the Drift, the position of its boulders, and the pecu- 

 liarities of the isolated mass of rock above described are not further 

 treated of ; but the author has to observe, that by numerous traverses, 

 both on the east and west of the line, he has found the Drift cover- 

 ing a considerable extent of country, and apparently ranging as a 

 band about six miles vride, in a N.E. and S.W. direction. 



Casewick Cutting (fig. 2). — Freshwater beds. — The Casewick Cut- 

 ting traverses oolitic rock, which represents the Kelloway Rock and 

 Oxford Clay. These strata are overlaid by a deposit of gravel 7 or 8 feet 

 thick. Towards the central part of the cutting a freshwater deposit is 

 intercalated between the oolite and gravel, occupying an excavation in 

 the surface of the former. This deposit is about 30 yards in width, and 

 it has an average thickness of about 8 feet, and varies in thickness 

 and character on each side of the cutting. It consists in the upper 

 part of grey sandy clay, 2 feet ; brown sandy clay and veins of gravel, 

 \\ foot ; a layer of peaty clay with fragments of plants and shells, 

 1 \ foot ; dark sandy clay, with plants and shells, pebbles of chalk 

 and flint, and portions of the northern clay drift in fragments. The 

 base of the deposit is extremely irregular in outline (see fig. 2, 3), and 

 the surface of the oolitic stratum is slightly disturbed and re-aggre- 

 gated, as it is throughout the cutting. The following is the list of 

 shells* and plants obtained; no bones, however, were observed : — 



Bithinia tentaculata, "1 



and opercula > Plentiful. 



Valvata piscinalis ....J 



cristata Rather rare 



Planorbis marginatus \ t;„ „ 



carinatus J 



imbricatus Only one. 



Limneus pereger T Rare and im- 



Succinea putris f mature. 



Ancylus fluviatilis ...1 Rather plenti- 



Veletia lacustris j" ful. 



Cyclas cornea Rare : frag- 

 ments. 

 Pisidium amnicum .. Rather rare. 



* The above list has been corrected by Mr. Pickering, who also kindly examined 

 some portions of the clay from this deposit. To Mr. T. R. Jones I am obliged for 

 determining the above-mentioned Cyprides. 



