354 A. J. Jukes Broicne — On the Upper Greensand, etc. 
and were, I believe, the first to point out the threefold division 
of the Upper Greensand as developed in Hampshire and Surrey. 
They say : “ It commonly comprises three distinctive formations ; 
the first is a thin green band of marl, more or less siliceous, and 
abounding in organized fossil remains ; it lies below and in contact 
with the soft dirty white ruarlabove metitioned ; in thickness itvaries 
from a few inches to 10 or 15 feet. The second division is the fire- 
stone rock, the thickness of which also varies. . . . This rock 
gradually merges into a soft clayey marl, which constitutes the 
third sub-di vision, and this again in its inferior parts becomes more 
and more argillaceous, until it is finally lost in the Gault.” Mr. 
Godwin-Austen, vvriting in the same year, makes a similar division 
of the series near Guildford, 1 but refers the lowest green rnarls and 
clays containing phosphatic nodules to the Gault. 
Here, again, there is no definite base-line for the Upper Green- 
sand, and certain clayey marls are referred by one observer to the 
Gault and by others to the Greensand ; it will be seen in the sequel 
that I look upon the former mode of grouping as the most correct. 
In 1862 two memoirs were published by the Geological Survey 
describing the Isle of Wight and parts of Hampshire and Berkshire 
(Sheet 12) ; no detailed sections of the Gault and Greensand are 
given in either of these works, but the following may be deduced 
from the description on p. 24 of Mr. Bristow’s “ Isle of Wight,” and 
may be compared with those on a previous page. 
Feet 
( 1. Calcareous Sandstone 20 
j 2. Chert, Sandstone, and Freestone ? 16 
( 3. Sands and Sandstones ? 24 
) 4. Yellowish-grey sand with some Sandstone and Chert (P Rag) ... 40 
5. Bluish sandy micaceous beds 55 
165 
It is to be regretted that the fossils found in these beds were not 
given separately instead of being. combined into a general list. 
As regards the base-line, Mr. Bristow says (p. 23) : “ Sometimes 
the Gault assumes a very sandy character, and passes so insensibly 
into the Upper Greensand as to be searcely distinguishable from it.” 
A section also is given showing the passage from Gault to Greensand, 
and the bluish sandy clays are stated to contain Grypluca vermicularia 
and Area ; the line is maiuly drawn to separate sands from clays, 
the sandy clays being mostly included with the Upper Greensand, 
and not with the Gault (see ante). 
In the Memoir on Sheet 12 the Upper Greensand is described as 
consisting of the same three divisions previously indicated by Messrs. 
Paine and Way, viz. (1) Greensands ; (2) Malm rock ; (3) Soft 
sandy marls ; but the former of these is referred to the Chloritic 
Marl, leaving the other two only to constitute the Upper Greensand. 
Thus we find that there is great uncertainty botli concerning the 
upper and lower limits of the formation, and that the only beds 
which all agree in calling Upper Greensand are the Malm-rock and 
1 Quart. Journ. Geol. Soc. vol. iv. p. 257. 
