INFERIOR OOLITE: COLLYWESTON. 
FIG. 55. 
Section at " Slate-mine^ Collywcston, Stamford. 
197 
Lincolnshire 
Limestone. 
Collyvf eston Slate - -I 
Lower Estuarine / 
Series. I 
5. Marly and oolitic limestones with 
occasional sandy beds - 10 or 
4. Sand with curious concretionary 
nodules and thin irregular slabs, 
that occur in undulating layers (in 
one place to the number of 37) 
and coalesce with oolitic and sandy 
stone at base [Top Sand] - 
3. Hard brown oolite ; passing down 
into pale gritty limestone and 
calcareous sandy stone (forming 
roof-bed of mine) - 
2. " Slate " ; fine-grained calcareous 
sandstone - - - 3 to 
1. Soft yellow calcareous sand and 
sandstone. 
FT. IN. 
12 
3 
6 :o 
The "Slate" is here mined, and the galleries are supported by piled 
slabs of stone. A more particular account of the " slates " will be given 
in the chapter on Economic Products, p. 483. 
The strata above the slaty beds comprise oolitic freestones, and hard 
beds with scattered oolitic grains, that recall to mind the lower beds of the 
Great Oolite that are worked at Througham Field, near Bisley. The 
pot-lid structure so familiar at Stonesfield, is repeated at Collyweston. 
Altogether the beds are exceedingly variable in character. 
Full particulars of the strata have been published by Sharp, who has 
noted the quarrymen's names of the beds, and the fossils obtained from 
them. 
The bed No. 3 has yielded Natica cincta, Gervillia acuta, Hin- 
nites tumidus, Ceromya concentrica, Pecten aratus, Ferns, &c. 
Some of the layers are used as building-stone : they are known 
in ascending order as the Bitch, Hard Limestone, Hard Sand, 
and Brood. The upper beds, No. 5, also yield Natica cincta 
