158 
THE CRETACEOUS ROCKS OF BRITAIN. 
About 20 feet above this siliceous chalk a bed of very hard, com¬ 
pact, and heavy grey chalk, about 18 inches thick, crosses the road¬ 
way. Some 40 feet higher is another conspicuous bed, grey, but 
not quite so hard, 3 feet thick ; this has some resemblance to Tot- 
ternhoe Stone and examination with a microscope showed that it 
contained much glauconite and many fragments of silicified Ino- 
ceramus shell, but we do not consider it to be on the same horizon. 
A third hard bed, whitish and compact, occurs still higher, about 
half way between the last and the Melbourn Rock. The descend¬ 
ing section is therefore as follows : — 
ft. 
Melbourn Rock at level of about 570 feet. 
to 
«4_ S> 
X r-O 
S 3 
/■Whitish chalk. 
Hard compact white chalky limestone - 
J Whitish chalk. 
\ Rather hard grey gritty chalk - - - 
Greyish-white chalk - 
LVery hard, compact and heavy grey chalk - 
5-t-l 
o 
<v 
a 
o 
S 3 
Greyish-white chalk 
Rather hard greyish chalk - 
Soft whitish siliceous chalk - 
Siliceous chalk with concretions 
Soft whitish siliceous chalk - 
Chalk and chalk mar] (not seen) 
seen for 
about 
20 
o 
t-J 
20 
3 
40 
H 
H 
8* 
122 
Total 244 
Near the eastern end of the Vale of Pewsey the Lower Chalk is 
exposed in several of the cuttings on the Swindon and Andover 
Railway. The following notes on these are furnished by Mr. R J. 
BennettThe first cutting, about a mile S.S.W. of West Grafton, 
shows grey marly chalk with a kind of conchoidal fracture overlain by 
hard, grey, gritty chalk which dips southward at about 3°. The next 
cutting, about a third of a mile to the south, shows about 8 feet of 
hard, grey, gritty chalk weathering in a flaggy manner. A third 
cutting, about the same distance farther south and a little north 
of Collingbourne Kingston, is about 9 feet deep in soft greyish chalk. 
In the trackway leading to East Grafton, and about a mile east of 
the first cutting, hard siliceous chalk was seen, containing blue- 
hearted siliceous concretions, and similar chalk was seen in the 
high road west of Wexcombe Church. 
Mr. T. Codrington, describing the cuttings on the Marlborough 
Railway in 1865,* states that in the cutting “at Lye Lane there 
is a good section through part of the Lower Chalk, here consisting 
of hard, thick-bedded stone, dipping north at 8°.” In this he found 
the following fossils :—Inoceramus latus, Pecten Beaveri, Pecten 
(Neithea) quinquecostatus, Rhynchonella G-ibbsi [? grasiana], 4m. 
[$c/ii.] varians, Am. [ Acanth .] Mantelli , Turrilites tuberculatui and 
Sharks’ teeth. 
* Mag. Wilts. Arch, and Nat. Hist. Soc., Vol. ix. p. 16#. 
