LOW Eft CHALK—SURREY. 
51 
r 1 2 .—Surrey. 
'] . .■ : -1 ' . V -V . 
General Description. 
The Lower Chalk of Surrey is a continuation of that of Kent, 
but its outcrop becomes much, narrowed near Guildford, in conse¬ 
quence of the steeper inclination of the beds. 
There is no well-marked basement bed to the Chalk of Surrey, 
except in the extreme west near Farnham. Everywhere between 
Godstoneand Guildford the Selbornian sand passes up into a glau¬ 
conitic sandy marl, and this into a soft chalky marl without 
glauconite. Part of this passage is doubtless to be regarded as 
representing the Cliloritic Marl or zone of Stauronema Carteri, but 
as fossils are rare, and the usual brown phosphates are almost 
completely absent, it lacks the usual characteristics of that horizon. 
The Chalk Marl above is of a greyish-buff colour, very soft at 
the base, but passing up into firmer greyish-white marl, succeeded 
by marly chalk with hard concretionary masses, in which Am, 
[, Schloenbachia ] varians is common. t The central part of the stage 
consists of firm grey chalk, in which Holaster subglobosus, Pecten 
Beaveri, and a few other fossils occur. 
The upper beds of the Lower Chalk present the same characters as 
those in Kent, being massive, blocky and whitish, till the marly 
chalk of the Belemnite band is reached. 
The total thickness is probably about 200 feet. In the Streatham 
boring it was found to be 188J feet; at Kichmond it is stated to be 
220 feet, and still further west, at Winkfield, it is 219 feet. The 
particulars obtained about this part of the Chalk in the Winkfield 
boring may be summarised as follow : — 
ft. in. 
White and green chalk (? Belemnite marls) --*>60 
White chalk, some parts free-cutting, but most of it hard 105 9 
Hard grey chalk, the lower part being of a dark grey colour 35 3 
Blue and brown marly chalk - - - - •' - -22 0 
Grey (1 marly) chalk with hard layers from 1 to 13 inches 
thick - - 50 0 
219 O 
The base was fixed by the examination of a sample from the depth 
of 939 feet, which showed the characters of the Chloritic Marl. If 
the description is to be trusted with regard to colour, the thickness 
of white chalk here is unusually great, but the succession of White 
Chalk, Grey Chalk, and Chalk Marl is clearly shown. 
Zone of Ammonites varians* 
Chloritic Marl.— The passage beds from Upper Greensand 
to the Chalk are well seen in the quarry at Colley Hill, near 
Keigate. 
4219. d 2 
