198 
THE CRETACEOUS ROCKS OF BRITAIN. 
The Totternhoe Stone. 
The outcrop of this stone enters Cambridgeshire a little east of 
Ash well, and its base is seen in a chinch-pit east of Shepreth, the 
basement bed enclosing a number of hard green-coated nodules, 
which consist of marly chalk indurated by the infiltration of a 
certain amount of phosphate of lime. 
The top of the Totternhoe Stone is exposed at the bottom of the 
large quarries at Cherry Hinton, and some depth of it was formerly 
worked for building-stone, but only 4 or 5 feet are now visible. 
There is no definite upper limit to the stone, but a gradual passage 
from rough-feeling greyish-brown stone into compact grey chalk. 
The best sections of the Totternhoe Stone as a whole are to be 
found in the pits at Bur well, about half-way between Cambridge 
and Mildenliall. Here it has long been worked, and is still occa¬ 
sionally quarried for building-material and for mouldings in the 
interior of churches. The upper beds are exposed in the quarry 
near the church, and the section seen here in 1878 was : — 
ft. 
Soil and chalk rubble ------- -4 
Thin-bedded greyish-wliite chalk ------ IQ 
T Hpvntnn I Hard brownish-grey stone projecting in the 
C gtone | weathered face of the pit ----- B 
I Softer grey stone in thick beds - - - seen for 10 
27 
The uppermost lied is called the “ bond " or “ bond-stone ” by 
the workmen, and makes the best building-stone. The lower beds 
are now generally burnt for lime ; they are said to be more than 
15 feet thick. Fossils are abundant, and Am. [ Acanthoceras ] rotoma- 
gensis is especially common in the “ bond/' 
In the Victoria Quarry, to the north, the lower part of the stone 
is exposed, with the basal nodule-bed resting on Chalk Mail and 
dipping at about 3° to the westward. The following section was 
taken along the north face of the pit in 1878 : —- 
ft. 
Father hard grey Totternhoe Stone, with a nodule bed at the 
base, varying in thickness from 6 to 12 inches, - - about 13 
Tough marly and blocky clialk-marl - - - - - 15 
The nodules are calcareo-pliosphatic, brownish inside, but gene¬ 
rally green outside ; they are of all sizes, from that of a pea to a 
medium-sized potato, irregularly oval or kidney shaped, and often 
bear the attached valves of small oysters and Plicatulcc. This 
nodule-bed is called “ brassil ” by the workmen, and is carted away 
for road metal, the rest of the stone as well as the Chalk Marl being 
burnt for lime. Analysis shows that the Totternhoe Stone here 
contains about 86 per cent, of carbonate of lime. 
The same nodule-bed, with a few feet of the overlying stone, 
was once exposed at the south-western corner of the large quarries 
at Reach. 
