21.8 THE CRETACEOUS ROCKS OF BRITAIN. 
thick, and contains many fossils. It was called the “ grey bed " 
by Mr. W. Hi ll, who first identified it with the Totternhoe Stone 
in 1887, after he and I had traced that stone through Norfolk 
in the previous year.* In minute structure it is also comparable 
with typical Totternhoe Stone, for it consists chiefly of minute 
fragments of shell, with many Foraminifera and an abundance 
of glauconite grains. 
Immediately above the Totternhoe Stone there is always a course 
of hard nodular greyish-white chalk, in which large Ammonites 
( Hapl . lewesiensis and Hapl. Austeni) frequently occur. The 
next 6 or 7 feet are marly, and in the Louth district they are of a 
pink or light red colour. Above this band are thick beds of hard 
whitish chalk, part of which is, however, coloured pink or yellowisli- 
pink in the Louth district. 
The total thickness of this part of the zone is from 38 to 40 feet. 
Belemnite Marl. —After the disappearance of these marls in 
Norfolk it is somewhat surprising to find them well developed in 
Lincolnshire. There is, however, no doubt about their occurrence, 
for not only do they occur in the same relative position as those 
of Cambridge and Herts, but they have similar characters, and in 
at least one locality they contain the characteristic fossil. 
At the south end of the Wolds thev include a bed of hard whitish 
*/ 
chalk like that seen elsewhere, but this does not recur, and in many 
places the whole band consists of soft grey laminated or shaly marl, 
often variegated with purple or brown. In some sections there is 
a medial bed of grey marly chalk, but this is not like the hard 
white chalk above mentioned. The lowest layer generally encloses 
numerous pebbles of hard chalk. This band of shaly marl varies in 
thickness from 1J to 3 feet, and is a conspicuous feature in all the 
pits where it is exposed. 
From analyses made of these marls by Mr. Meabourn Staniland 
and Mr. Grant Wilsonf it would appear that the carbonate of lime 
varies in amount from 61 to 86 per cent., the siliceous or argilla¬ 
ceous ingredient varying inversely from 28 to 9 per cent. 
Stratigraphical Details. 
Zone of Ammonites varians. 
A good section of the lower part of this zone is exposed in the 
quarry on the west side of the road half a mile north of Candlesby. 
Since 1877, when the section given in the Survey Memoir on Sheet 
84 was taken, the pit has been cut further back, exposing 4 feet 
more of the platy chalk, so that it now reads : — 
* See Quart. Journ. GeoLSoc., Vol. xliv. p. 325, 1888. 
t See Geology of East Lincolnshire ; Geol. Survey Memoir, on Sh. 84. 
p. 38, 1887. 
