Lower chalk—Lincolnshire; 
219 
Bubbly soil -. - 
Platy chalk with two of grey shaly marl 
Whitish chalk, lumpy and irregularly bedded - 
Bluish-white chalk drying nearly white, called- “ the blue 
course ” ---------- 
Inocera- 
in us 
Beds. 
Massive grey gritty chalk in two courses, with 
shaly marl at base - - 
Hard nodular grey chalk, with layer of shaly marl 
at base -------- 
Sponge Bed—hard nodular pink and yellow rock 
Layer of red marl (persistent). 
Gault—rrd limestone with marly partings - 
ft, 
1 
8 
14 
O 
4 
1 
2 
6i 
Tlie upper beds of this zone are seen below the Totternhoe Stone 
in a neighbouring quarry to the north-west, opposite the Cross Keys 
Inn. 
Other good sections of the lower beds are found in the quarry 
north-east of Grebby Hall, and in another pit half a mile north¬ 
west of Dalby Church. In the latter the Sponge Bed is in two 
courses, and is 2 feet 9 inches thick. The Inoceramus Beds are over 
5 feet thick, and 13 feet of the overlying beds are exposed. 
A quarry east of this at the junction of the roads south of Dex- 
tliorpe exposes still higher beds, being about 20 feet deep and just 
touching the Inoceramus Beds at the bottom. 
The basement beds are also visible in the deep valley east of Swaby, 
where a quarry shows : — 
ft. 
Greyish-white chalk in irregular beds - - - - - 8 
Inoceramus Beds—hard grey gritty chalk full of Inoceramus 
shell - -- -- -- -- -- 4 
Sponge (Very hard nodular yellowish chalk- - - - 
g e( pT I Hard lumpy yellowish-red chalk with cylindrical 
^ bodies --------- 21- 
Parting of dark red clay. 
Gault— brick-red limestone in regular beds - - - - 4 
It will be noticed that the basal yellow limestone or “ Sponge 
Bed ” is here unusally thick (4 feet). 
Another good section of these beds is exposed by the cutting at 
the west end of the tunnel near Withcall, on the Louth and Lincoln 
line. 
In North Lincolnshire there are not many exposures, but the 
lower beds above the Bed Chalk are seen in a quarry above the 
Hospital at Worlaby, N.N.E. of Brigg. 
Exposures at Thorpe-le-Mire, north-east of Market Basen, show 
how constant these several subdivisions are. Mr. Strahan saw 
the following beds in a quarry north-east of the village : — 
