152 
THE CRETACEOUS ROCKS OF BRITAIN. 
ilf, i- ft. 
Hard greyish-white chalk in layers, having alternately a 
rough and a smooth fracture ------ 6 
Layer of soft grey marl ..0 
Hard grey chalk - - - - - < - 3 
Soft dark grey marly chalk -.1 
Dark grey sandy chalk, with visible grains of glauconite (many 
fossils) --------- about 15 
Very hard light grey limestone ------ 1 
Soft grey marl below. 
The grey sandy chalk is not unlike Totternhoe Stone, and con¬ 
tains many of the same fossils, but there are no pliosphatic nodules 
or fragments in it. 
There are no good exposures of this zone on the north side of the 
Vale of War dour, nor are there any worthy of special notice near 
Mere or Maiden Bradley. 
West of Warminster and south-east of Clay Hill Farm siliceous 
chalk occurs in a small pit about 50 feet above the Greensand. Mr. 
W. Hill has examined a sample of it, and informs me that it contains 
much globular silica and many sponge spicules. It is a firm blocky 
greyish-white chalk, and about 6 feet are exposed. In the "cart- 
track which passes by the pit six layers of hard chalk are seen, three 
above and three below the siliceous chalk, and one of these is 
also siliceous. 
The lower beds are exposed in the railway cutting near TTpton 
Scudamore. They consist of soft grey marly chalk in courses 3 or 
4 feet thick, alternating with layers of hard grey chalk. These 
beds contain Am. [Schloenb.] varians , Am. [Acanth.] Mantelli , Tur- 
rilites scheuchzerianus , and other characteristic fossils. They dip 
gently southward, and south of the bridge some higher beds come 
in, which include a band of rather soft brownish-grey chalk, about 
4 feet thick, which has much resemblance to Totternhoe Stone, 
but is too low in the zone to be its representative. 
Some of the higher beds are visible at the bottom of the road 
leading to Upton Cow Down. These are about 100 feet above 
the Chloritic Marl, and consist of firm blocky chalk, with four 
courses of hard greyish-white chalk, which stand out as steps or 
ledges on each side of the cart-track. 
The greater part of the Lower Chalk is well exposed in the road 
cutting south of Tinhead, between Lavington and West bury. I 
did not visit this section myself, and am indebted to my friend 
the Bev. W. B. Andrews for the following account. The thicknesses 
are eye-estimates only, and the higher beds are not so clearly seen 
as the lower. The outcrop of the Melbourn Bock is not exposed : — 
ft. 
'S a s 
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a} O 
O .f* -S 
tsjtlj 
'Soft light grey chalk - 
Course of very hard chalk - 
Soft light grey chalk - 
Course of very hard chalk 
about 
» 
50 
1 
50 
1 
