GEEAT OOLITE: NORTHLEACH. 
299 
neighbourhood 
of 
basement-beds (Stonesfield Series) of the 
Bisley. 
Between Northleach and Shipton-under-Wychwood the Great 
Oolite has yielded important beds of freestone in its lower 
division. The general sequence of the beds is difficult to deter- 
mine in many places, but it is as follows : 
FT. IN. 
f White limestones, shelly and more or 
less oolitic, with occasional beds of 
marl and brown limestone ; with two 
or more fossil-beds with Corals, Gas- 
teropods, Lima cardiiformis, Tere- 
bratula maxillata, &c. 
Marls with bands of oolite and clays ; 
with Ostrea, T. maxillata, Serpula, 
&c. - - - - 18 to 25 
Pale flaggy and shelly"] 
oolite, and current- 
bedded white oolitic lime- | 
stone and marl - - | 
Obliquely bedded oolite )> 12 to 20 
(freestone) ; coarse and 
shelly in places, with 
Clypeus Mulleri, Isastrcea, 
^ &c. 
/Fissile sandy limestone and marl 
about 4 
White Lime- 
stone. 
1 
Marly Beds 
-< 
Freestone 
-< 
Stonesfield 
Beds. 
. 
12 
The general section compares well with that seen in the 
Hampen Cutting (p. 292;, although there is a considerable diminu- 
tion in the thickness of the White Limestone and of the Free- 
stone. Near Northleach many Corals have been obtained from 
the ploughed fields. 
It is not improbable that in this neighbourhood the Forest 
Marble rests on different portions of the Great Oolite. The 
quarry at Hensgrove in Wychwood Forest, showed (at the base 
of the Forest Marble) an irregular white oolitic and marly lime-" 
stone with pebbly portions, that appears to be a remame bed of 
Great Oolite ; and a section west of Burford noted by Prof. Hull, 
affords similar evidence, with also waterworn fossils.* 
Prof. Hull has stated that in the neighbourhood of North- 
leach, " the greater portion of the Stonesfield slate, or lower zone, 
passes into an oolitic freestone."t That the series is to a certain 
extent an interchangeable one, is borne out by the evidence 
afforded by the railway-cuttings between Chipping Norton and 
Hook Norton, where beds resembling Stonesfield Slate overlie 
beds of oolite ; but over great part of the Gloucestershire area, 
beds of a slaty character occur at the base of the freestone. 
Prof. Hull notes a quarry east of Leygore Farm, north-east of 
Northleach, which showed slaty beds at the base of the Great 
Oolite, as follows! ; 
* Geol. Cheltenham, p. 63. 
t Ibid., p. 55. 
J Ibid., p. 56. 
