INFERIOR OOLITE: PEA GRIT SERIES. 113 
FT. IN. 
^Freestone, with oolitic grains sparingly 
| distributed - - - 10 
P P 't I Oolitic limestone, mainly composed of 
oolite with bands or seams of shelly 
oenes J_A *j p , i_ _/? i TTI_T_'_' 
(Lower 
Limestone). 
detritus, fragments of coral, Echini, 
and oolitic grains, and the upper 
surface covered with minute valves of 
Ostrea. A. good weatherstone, but 
worked with difficulty - - 16 
Witchell noticed that these beds of limestone are in places 
pisolitic and highly crystalline, and that they sometimes contain 
rolled . fragments of limestone and small quarlz pebbles. He 
observed the beds at Cam Long Down, near Dursley, and at 
various points along the hills by Stroud to Leckhampton. 
The beds yield a number of small Gasteropoda Cerithium, 
Ceritella, Monodonta, Nerita, &c., and fragments of Ncrincea ; also 
Ostrea, Pentacrinus, Cidaris, and Polyzoa. 
Mr. S. S. Buckman observes that the Lower Limestone and 
underlying Brown Ferruginous Beds may perhaps belong to the 
zone of Ammonites opalinus* 
Pea Grit. This bed consists of hard and soft bands made up 
to a large extent of small bean-shaped and, less frequently, pea- 
shaped concretions. Where disintegrated the slopes beneath the 
exposed rock, as at Crickley, are strewn with the little concretions. 
The bed has been long known to the inhabitants of the district as 
the " Pea Grit," and is less commonly termed Pisolite. As early 
as 1729 " Pisolithi " were noticed by Dr. John Woodward, on the 
hill between Cirencester and Gloucester,t evidently Birdlip, where 
the beds are well shown, and have a thickness of about 20 feet. 
The name Pea Grit was adopted by Murchison in 1834.J 
Alternating with the layers of Pea Grit, there are bands of 
hard pisolitic limestone, and there can be no doubt that the 
" Lower Limestone " is so represented in places, and at Cnckley 
we have no need to make any subdivisions ni the Pea Grit Series. 
The harder beds have been quarried for building-stone at Crickley 
and Leckhampton. The thickness of the series is here about 
38 feet. 
The Pea Grit as a separate bed has been traced by E. Witchell 
as far south as Coaley Wood, near Uley Bury, where it is 9 inches 
thick, at Horsiey where it is 3 feet, and at Longford Mill, near 
Nailsworth, where it is 5 feet. It has been observed by Prof. 
Hull || as far north as Nottingham Hill, but has not been detected 
on Robin's Wood Hill. Eastwards he has noticed it at Coles- 
borne, and it occurs also near Andoversford. (See Fig. 41.) 
Witchell has remarked that ' The coral bed above the pea- 
grit consists of masses of coralline limestone, embedded in a 
* Inf. Ool. Ammonites, pp. 7, 42 ; seealso Hudleston, Address to Geol. Soc., 1893, 
Quart. Journ. Geol. Soc., vol. xlix. (Proc.), p. 126. 
t Nat. Hist. Foss., Eng., Part 1, p. 30. 
j Geol. Cheltenham, p. 33. 
Quart. Jcum. Geol. Soc., vol. xlii. p. 2G6. 
[j Geol. Cheltenham, p. 33. 
E 75928. H 
