352 A. J. Jukes Browne — On the Upper Greensand, etc. 
the Gault and Chalk-marl, and to review some of the conclusions 
arrived at by different writers on the subject, in Order tliat the way 
may be paved towards tlie establishment of a better nomenclature, 
and a more natural Classification in tbis part of the geological series. 
The Upper Greensand. 
The early history of this formation is chiefly connected witli that 
of the Wealdeu area, where the Firestones and Greensands below 
the Chalk had attracted attention in the beginning of the present 
Century; it was to these I believe that the terui “ Greensand ” was 
first applied : thus in William Smith’s Mernoir (1815), the suc- 
cession of the strata is correctly given as follows : 
Chalk (Upper and Lower). 
Greensand parallel to the Chalk. 
Blue marl (viz. Gault). 
Kentish Rag, etc. 
This last, however, and some other beds between the Gault and 
Weald Clays, being likewise of a green colour, came also to be 
spoken of as “ the Greensand.” Thus Conybeare and Phillips, in 
1822, showed the Firestone-beds of Merstham to be distinct from 
the Greensand, and separated therefrom by a blue marl which they 
doubtfully refer to the Cambridge Gault. They also distinguish the 
[Lower] Greensand from the Hastings beds of the Weald, then 
called “ Iron sand ” ; but they do not make the same distinction in 
the Isle of Wight, where their Greensand is the Upper Greensand. 
It was left for Fitton, in 1824, 1 to finally clear up doubts and 
difficulties which attended the correlation of the Greensands and the 
Iron sands, and by him the whole series was correctly described 
both in the Wealden area and in the Isle of Wight. 
It being thus proved that there were two horizons where beds of 
Greensand occurred, viz. above and below the Gault or “Blue 
marle,” it was natural that these should come to be called the 
Upper and Lower Greensand. Sir R. I. Murchison seems, however, 
to have been the first wbo actually made use of the name in any 
published paper : this being in his Mernoir on West Sussex, read 
before the Geological Society in 1825. 
Mr. Martin adopted the name for the beds in the northern part of 
the Weald, and Dr. Fitton in 1836 for those in the Isle of Wight 
and the south-east of England. The name was thus accepted as 
designating all the sandy beds between the Gault and Chalk-marl, 
and was a division founded purely on lithological characters, and 
without any reference to the fossils which its several component 
strata contained. 
The first attempt to estimate accurately the thickness of the Gault 
and Greensands is recorded in the Quart. Journal for 1845 by Mr. 
J. W. Simms, 2 the following section being measured between Ather- 
field Point and the cliff south of St. Catherine’ s Down : — 
1 Ann. Philos. ser. ii. vol. viii. pp. 365 and 458. 
2 Quart. Journ. Geol. Soc. vol. i. p. 77. 
