271 
CHAPTER X. 
GREAT OOLITE SERIES. 
GREAT OOLITE AND STONESFIELD SLATE 
(LOCAL DETAILS continued). 
Minchinhampton, Tetbury, and Cirencester. 
WE now come to the country around Minchinhampton, Tet- 
bury, and Cirencester, where the Forest Marble and Great Oolite 
cover an extensive tract of country, where there are many 
quarries and railway-cuttings, and where it has been found 
exceedingly difficult to fix a recognizable plane of division 
between the two groups. 
The fact is that false-bedded oolites occur at different horizons 
throughout the series ; beds of compact white more or less oolitic 
limestone, with the irregular cavities that characterize the Dagham 
Stone, form a division in which these cavernous beds occur, at two 
if not at more horizons ; fossil-beds yielding Terebratula maxillata, 
Lima cardiiformis, &3. are clearly impersistent for they appear 
as irregular beds or seams at different horizons ; and clays with 
Ostrea Sowerbyi occur in both Great Oolite and Forest Marble. 
There is indeed no band that can be relied upon as a constant 
horizon in the series. Even the Bradford Clay, as a fossiliferous 
bed, is to be found only here and there ; and as several marly 
layers occur in the upper part of the Great Oolite, it is quite 
likely that each one may locally be fossiliferous, and even yield 
a similar assemblage of organic remains. 
Prof. Buckman has remarked that he could by no means agree 
with Prof. Hull in his grouping of the upper beds of the Great 
Oolite. According to the former geologist, the upper portion of the 
Great Oolite comprises about 45 feet of "Yellowish oolite, with 
more or less of oblique lamination, sometimes separated into two 
or more stages with thin partings of sand or marl, [and it is] occa- 
sionally a hard compact freestone throughout." This division was 
generally grouped with the Forest Marble by Prof. Hull, who 
took the top of the White Limestone group as the upper limit of 
the Great Oolite. Prof. Buckman however maintained that the 
" yellowish oolite " is always found to occupy a position below the 
Bradford Clay, where that clay is present.* 
* Quart. Journ. Geol. Soc., vol. xiv. p. 113 ; Hull, Geol. Cheltenham, pp. 65, 66; 
Lycett, Quart. Journ. Geol. Soc., vol. iv. pp. 183, 185 ; and Morris and Lycett, Gt. 
Ool. Molluaca, p. 2. 
