1853.] MORRIS — LINCOLNSHIRE OOLITES. 329 



feet. 



Mottled clay with bands of Oysters 3 



Dark bituminous clay 1 



Compact sandy and occasionally soft shelly rock, with verti- 

 cal remains of plants ; the shells are not numerous, com- 

 prising the genera Natica, Modiola, Trigonia 3 



Stratified dark green and brown shelly clays 4 ' 



Stratified dark clays with layers of shells, not broken, and 

 indicating the beds to have been deposited under quiet 

 conditions ; the shells are Avicula, Cytherea, Pecten, 

 Lima, Ostrea, Terehratida, Lingula, and probably Cyrena 4 



Mottled and dark clays 6 



Bituminous band 0^ 



Stiff brown and greyish clays : no shells : numerous vertical 



plant-markings 7 



White and yellow clays 3 



Feri'uginous band 1 



Oolite, fine-grained and pinkish, the blocks occasionally with 

 blue centres * ; some of the beds coarser, and containing 



small shells, as Ceiithium and Ne7'incsa, from 1 2 to 1 3 



Two small sections of the oolite occur between this and Creeton 

 Cutting, which latter exhibits the following descending series : — 



feet. 

 Irregular laminated grey and green sands and clays, with 



layers full of shells in parts 6 



Soft sandy rock full of shells, as Modiola, Ostrea, Pecten. . l^ 

 Bituminous and dark green clays, with occasional shelly 



layers 5 



Greyish clays, in some parts finely bituminous (6 inches), at 



base 1 i 



Greenish sandy rock with vertical plant-markings 1^ 



Various-coloured clays, green, grey, brown, without shells. . 10 



Ferruginous band 1 



Oolitic rock, thick-bedded and horizontal, with occasional 

 false-bedding at the upper part ; inclination of oblique 

 laminee 30° N. 

 The Little Bytham Cutting presents a similar section, the beds vary- 

 ing somewhat in character (i. e. less fossiliferous) and thickness, 

 especially towards the upper part ; the sandy rock with Modiola is 

 wanting, but the clays are full of small Oysters and much thicker ; 

 the total thickness of clays is about 30 feet overlying the oolite f ; ihe 



* From some recent experiments it would appear that the blue colour of the 

 oolite maj' be due to the presence of sulphuret of iron : see a paper by M. Ebelniau, 

 Bull. Geo!. Soc. France, 2 ser. torn. ix. p. 221. 



t The clays which here cover the oolite (and the observation applies to the 

 whole district) have materially tended to its preservation as a solid rock, in pre- 

 venting the ordinary effects of atmospheric action, which, when the surface is not 

 so covered, causes it to split np into shivers and renders the ui)per ])art conijiara- 

 tively useless as a building material. This observation may be useful to those 

 who have occasion to search for or avail themselves of the building-stone of the 

 district. 



