110 
LOWER OOLITIC EOCKS OF ENGLAND! 
Cotteswold Hills Dursley to Leckhampton. 
The district extending from the north-east of Dursley to Stroud, 
Leckhampton. and Cleeve Cloud, presents us with the finest 
development of the Inferior Oolite in England, and one in which 
the greatest number of local subdivisions have been made. 
These are as follows : 
SOB-DIVISIOHS OF INFERIOR OOLITE SERIES. 
Thickness in 
Feet. 
Zones. 
r 
^ 1 White Freestone 
5 
] 
s i w 
&'H j Aiag- 
o. ] Clypeus Grit 
P L 
6 to 15 
V A. Parkinsoni. 
PT 
stones. 
jj f Upper Trigonia Grit 
2 to 12 
J 
5 
< Gryphite Grit 
_i3 L Lower Trigonia Grit 
| 2 to 12 
}A. humphriesiamts. 
* 
f Upper Freestone 
6 to 20 
--. d 
Freestones 1 Oolite Marl - 
5 to 10 
1 
1:1' 
[Lower Freestone 
Pea Grit f Pea Grit 
45 to 130 
3 to 20 
(A. Murchisonee, 
^^ 
Series. 
\ Lower Limestone 
10 to 25 
J 
Midford f Cephalopoda Bed 
Sand. \ Cotteswold Sands 
2 to 7 
10 to 120 
}A. opalinus and 
A.jurcnsis. 
These divisions have been noted from time to time by 
Murchison, J. Buckman, Strickland, Brodie, Lyeett, Hull, Wright, 
and Witchell.* 
Descriptions have previously been given of the Cotteswold 
Sands and Cephalopoda Bed (p. 103). We now come to the 
main mass of the Inferior Oolite. In this group, which attains a 
thickness of 250 feet at Leckhampton, we have a considerable 
development of the false-bedded oolites with few fossils, probably 
accumulated with rapidity \vhen compared with the more fossili- 
ferous Pea Grit Series below and the Ragstones above. 
There are at various horizons, fossil-beds rich in Echinoderms. 
Polyzoa, Brachiopods, and Lamellibranchs, but there are com- 
paratively few Ammonites and Belemnites, and, as will be seen, 
much difference of opinion has been expressed on the subject of 
zones. Four coralliferous layers have been observed on different 
horizons, and these bands furnish evidence of coral-growth in situ, 
though occasionally, as in the uppermost bed, there are indications 
of derivation. f As remarked by Mr. Hudieston, Nerin&a is 
associated with the coral-growths in the Cotteswold area, and this 
is a genus that has not been met with in the district south o 
Radatock in Somersetshire. J 
* Murchison, Geol. Cheltenham, 1834; Ed. 2, hy J. Buckman and H. E. Strick- 
land ; Brodie and Buckman, Quart. Journ. Geol. Soc., vol. i. p. 221 ; Brodie and 
Strickland, Ibid., vol. vi. pp. 239, 249, &c.; J. Buckman, Ibid., vol. xiv. p. 107; 
Wright, Ibid., vol. xvi. p. 1 ; Lycett, The Cotteswold Hills, 1857; Hull, Geology 
of Cheltenham (Geol. Survey), 1857 ; Witchell, Geology of Stroud, 1882. 
t See Tomes, Quart. Journ. Geol. Soc., vol. xxxviii. p. 412 ; Geol. Mag., 1886, 
p. 887 ; and Proc. Cotteswold Club, vol. ix. p. 301; Wright, Ibid., vol. iv. p. 148. 
J Gasteropoda of Inf. Oolite, p. 22. 
