LOWER CHALK--CAMBRIDGE AND SUFFOLK. 
197 
numerous “ coprolite pits/’ and good sections can still be seen in the 
trenches opened to obtain material for the Cement Works at Shep- 
reth, Barrington, and other places south-west of Cambridge. 
Besides these there are few permanent exposures of the Chalk 
Marl. One of the best is in a quarry south-east of Kingston, 
which is not far above the base, and shows about 20 feet, with 
two definite beds of grey sandy chalk, an unusual occurrence : 
the section seen here in 1876 being: — 
o 
ft. 
Rubbly chalk - -- -- - - - - 5 
Grey sandy chalk - - - - - - - - - 14 
Bubbly chalk marl ------- -3 
Grey sandy chalk - - - - - - - - - 1^ 
Hard blocky chalk marl -- - - - - - -10 
The middle beds of the Chalk Marl are exposed in a quarry half a 
mile W.S.W. of Harlton, and consist of loose greyish marl con¬ 
taining Rhynchonella Martini and other small Brachiopods. 
The highest beds are well seen in the large quarries near Beach. 
About 30 feet are shown here, the higher part consisting of tough 
blocky greyish-wliite marly chalk, passing down into softer and 
darker grey marl, and finally into bluish shady marl, of which 3 
or 4 feet are seen; these lower beds are full of fossils, and 
Inoceramus latus (d’Orb.) is common throughout. 
The position of these quarries and the undulation of the beds 
which brings in the small tracts of Totternhoe Stone at Reach and 
Burwell are shown in Tig. 47 : 
Road near Devil’s Burwell 
Fig. 47. Diagram-section from Reach to Burwell. 
Horizontal Scale 2 miles to an inch. Vertical Scale 200 feet to an inch. 
a. Totternhoe Stone, b. Chalk Marl. 
(From Memoir “On the Geology of Cambridge,” Fig. 9. p. 45.) 
A boring made for the Ely Waterworks at Isleham proved the 
Chalk Marl to be over 70 feet deep. 
In Suffolk the greater part of its outcrop or “ basset surface ” 
is concealed by a luvium and blown sand. 
4219 . ° 2 
