LOWER AND UPPER GREENSAND OF THE SOUTH OF ENGLAND. 
415 
been disintegrated and reduced to their individual elements. The organic nature of 
the rock does not appear to have been previously noticed. 
Godstone, Surrey. —About three miles east of the quarries at Merstham, beds of the 
same age are worked by the side of the high road north of the village of Godstone. 
There is here an upper bed of soft rock 5 feet 8 inches in thickness (1 36 m.), which 
is largely quarried for hearthstones. This rock is of a more friable character, and 
contains more calcite than the malm or firestone ; but empty spicular casts and 
spicules replaced by glauconite are present in it, and the silica is also in the amor¬ 
phous globular form. Beneath the hearthstone-bed there are beds 14 feet in thickness 
of malm or firestone, of a similar character to those at Merstham, and similarly filled 
with sponge-remains. In these there are at intervals parallel layers of the hard blue 
nodular aggregations known as flints, which are from 3 to 4 inches ('075 to T m.) in 
diameter. These nodules are not sharply delimitated from the inclosing rock, in the 
same manner as the flints in the chalk, but there is a gradual passage from one to the 
other. They are disposed, however, in definite planes of bedding in the same manner 
as the chalk-flints. The sponge-spicules are much more distinctly shown in these blue 
nodules than in the white portion of the rock. A magnified section of one of these 
nodules is shown on Plate 40, fig. 2. 
Reigcite and Betchworth, Surrey. —A short distance to the west of Reigate and 
again about two miles further west, close to Betchworth station, quarries are opened 
to obtain the hearthstones and firestones. In the upper beds of the quarries the base 
of the chalk marl is shown, and beneath this a bed from 4 feet to 8 feet in thickness 
of a soft greensand in which glauconite grains are very abundant. This bed repre¬ 
sents the chloritic marl. The hearthstones are here 10 feet in thickness (3 m.) and 
the firestone beds beneath are of an equal thickness. The character of these rocks 
closely resembles that of the "beds at Merstham and Godstone. 
Farnham, Surrey .—The upper greensand strata near this town were formerly largely 
worked for agricultural purposes and for building, but good sections are no longer 
exposed. According to Messrs. Way and Paine, # who have given a detailed 
description of the beds, they have a total thickness of over 60 feet, of which the 
upper 40 feet (12 m.) is a soft friable rock, known as malm or soft Surrey sandstone, 
and the lower 20 feet (6 m.) is of a harder character, and is called firestone. 
The malm rock is of a creamy-white tint, and very soft and porous, and of relatively 
light gravity when dried. With the exception of a few mica-scales and particles of 
glauconite it appears to be entirely siliceous. Its friable character does not permit 
microscopic sections to be made from it, but reduced to powder and examined in 
Canada balsam, fragmentary spicules both of silica and of glauconite can be seen in it. 
The greater part of the silica in the rock is in the globular form, and the minute 
globules or discs occur detached in the powdered material (Plate 45, figs. 18-186). 
This globular silica, as well as that of the spicules, is in the amorphous condition and 
* ‘ Journal of the Royal Agricultural Society,’ vol. xiv., 1853, p. 232, et seq. 
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