160 
THE CRETACEOUS ROCKS OF BRITAIN. 
ft. 
Grey flaggy chalk --------- 3 
Grey marly chalk, weathering into balls - - - - - H 
Grey flaggy chalk ------- -2 
Marly chalk - 1 
Grey chalk with curvilinear jointing ----- 2 
Massive grey blocky chalk, seen for - - 4 
He obtained Am. [Acanth .j cenomanensis, Nautilus elegans, and 
Lima elongata from the quarries. 
Similar chalk is exposed in the roads leading down the escarp¬ 
ment to Bassett Down House and to Lower Quidhampton. 
A well sunk in 1901 at the farmstead on Bassett Down, belong¬ 
ing to Mr. N. S. Maskelyne, traversed a large part of the zone of 
Am. varians and most of the underlying malmstone. I am indebted 
to the contractor, Mr. J. W. Titt of Warminster, for particulars and 
for samples of the beds traversed, from which information and 
from notes taken by Mr J. Scanes the following account has 
been drawn up. 
/ 
r* 
ci 
D=i 
P 
f-t 
CD 
O 
S 
cS 
• rH 
£ 
O 
.O 
13 
m 
ft. 
30 
30 
Alternations of hard and soft grey chalk - 
Tough grey chalk, apparently without hard beds 
Bather hard grey chalk containing pieces of Inoceramus 
latus , Am. [>SrA/.] varians and Nautilus elegans - 20 
Hard bluish-grey chalk with Inoc. latus and Am. varians 10 
Bluish-grey marly chalk with Am. varians - - - 17 
Mottled grey and buff chalk-marl with Am. varians and 3 
Turrilites Bergeri - - - - - - - 5 
Hard grey sandy chalk with some glauconite grains - - lj 
Dark grey sandy glauconitic chalk with blackish plios- 
pliatic nodules (Chloritic Marl) ----- Of 
Grey fine-grained micaceous sandstone with some softer 
bands ---------- 17 
Grey micaceous malmstone, partly hard and partly soft - 23 
Dark grey malmstone and sandy marl - - - - 11 
165 
The lower part of the zone is well exposed in the cuttings near 
Chiseldon Station, and the following account has been written 
from notes furnished by my colleague, Mr. F. J. Bennett. 
“ In the middle of the cutting north of Chiseldon Station about 
40 feet of Chalk Marl is exposed. It consists of alternating soft 
and hard beds ; the soft beds are the thickest, and consist of marly 
chalk, weathering into spherical lumps and traversed by oblique 
curvilinear joints or planes of separation ; the hard beds consist of 
compact greyish chalk, are seldom more than 8 inches thick, but 
stand out as ledges along the face of the cutting. 
“ In the cutting south of Chiseldon Station the first chalk seen 
is firm, jointed, and bedded, but about half-way toward the first 
bridge a bed of hard grey, gritty chalk, full of small glauconite grains, 
comes in, and dips southward at about 3°. This bed has a remark¬ 
able structure containing much fine angular quartz-sand and 
much globular colloid silica. Similar beds come in further south, 
and at the bridge by Bush House, where the cutting is about 15 
feet deep, there are three beds of hard, grey, gritty chalk, each 
about 6 inches thick with softer chalk between.” 
