378 LOWER OOLITIC ROCKS OF ENGLAND : 
through 4 feet of green clay, and 19 feet of hard rock (Great 
Oolite). 
The Forest Marble has been traced as far as Bucknell, near 
which a small outlier, described by Prof. Green, consists of 
" coarse, reddish brown, flaggy limestone, very much false-bedded." 
He adds that " Beyond this point the Forest Marble seems to 
thin rapidly away, and traces of it have been found only in a 
few places. It nowhere reaches a thickness of more than three 
or four [15] feet, and as it would have been impossible to trace 
so thin a bed over xi drift-covered country, it has been left out 
on the map, except at those spots where sections prove it to be 
present."* 
Sandy and marly clays and hard blue fissile limestones, with 
Ostrea, spines of Echini, &c. wera seen in the valley east of 
Tingewick. These were grouped somewhat doubtfully with the 
Forest Marble by Prof. Green : but there can be little question 
that they form the commencement of the group which to the 
north-east is denominated '' Great Oolite Clay." This group is 
practically equivalent to the Forest Marble, The section given 
f>y Prof. Green of the (now disused) clay-pit on the Bourton 
road, near Buckingham, showed beneath the Cornbrosh, a 
thickness of about 15 feet, of blue clays with bands of sandy and 
marly limestone, that should be grouped with the Forest Marble. 
The beds were more clearjy shown at Lillingston Lovell, where 
the following strata were exposed in a quarry : 
FT. IN. 
Dark brown clayey soil. 
fKubble and white marl - - -"| 
Clay 
} (j\ 
tf j. TI/T i i J Current-badded calcareous sandstone - [ 
Forest Marble -< TMn ghalo ^ grifcty laminge _ . J 
] Blue shelly and oolitic limestones, 
! rotten in places - 60 
Pale compact and shelly limestone, 
I oolitic in places, with Cyprina, Ger- 
Great Oolite -< villia, Terebratula, &c. - 1 7 
I Greenish-grey clay - 4 
'^Brown oolite. 
The top bed of the Great Oolite here resembled the upper bed 
in a quarry near Akeley Brickyard, and that in "the Woodstock 
railway-cutting. The beds of Forest Marble are variable in 
character, and do not exceed 10 or 15 feet in thickness. 
At Thornton to the south-west of Stony Stratford, the following 
section was noted by Prof. Green f : 
FT. Ix. 
Cornbrash 
["Alternations of white, bluish, and 
Forest Marble - < brown clay, white beds of smooth, 
[ evenly jointed white marl - - 10 
Great Oolite - White shelly limestone. 
* Geol. Baubury, pp. 28, 29, 31. 
f Ibid., p. 28, 
