394 
LOWER OOLITIC ROCKS OF ENGLAND : 
no evidence of Upper Lias. On the contrary, the clay is of 
a variegated character, having in places greenish, purplish, and 
reddish tints; it contains marly bands and fragments of Ostrea. 
At Stoke Goldington the clay, which was exposed to a depth 
of 5 or 6 feet, contains, at a lower level, irregular concretionary 
slabs of pyrites, nodules of earthy limestone, and seams of 
fibrous carbonate of lime like " beef," but exhibiting well-marked 
" cone-in-cone " structure. This structure, under the name of 
nail-head spar, is frequently found in the Upper Lias Clay ; but 
layers of beef are not uncommon in the Upper Estuarine Clays, 
as in eome portions of the Purbeck Beds, with which they have been 
compared in general characters. It is not unlikely that deeper 
excavations at Stoke Goldington would expose the Upper Lias. 
Mr. Cameron informs me that at the disused brickyard, south 
of Olney, the beds worked were yellow and blue clay, with a 
sand-bed 1 foot thick, at the depth of 8 feet from the surface, and 
thus beneath the level of the Alluvium. This sand-bed may 
perhaps be a representative of the Northampton Beds. 
A well sinking (1891) one-half mile north of Olney railway- 
station, showed the following section, of which the details were 
communicated by Mr. Cameron : 
Great Oolite 
Limestone. 
TT TT, , . I Limestone 
Upper^Estuarmej Black clay 
{Limestone, with Modiola imbricata 
and RJiynchonella concinna - 
f Grey clay 
FT. Is. 
Series. 
I Black shelly and carbonaceous clay 
l_ with lignite on top 
18 
10 
2 
10 
45 2 
The character of ail the clays here is more like that of the 
Upper Estuarine Series than the Upper Lias. 
At Olney Court, according to Mr. Cameron, 20 feet of Lime- 
stone (Great Oolite) was proved, and beneath that 100 feet of 
clay. This clay would represent both Upper Estuarine Series 
and Upper Lias. Wells on the flats between the market-place at 
Olney and the river, are from 60 to 80 feet deep. It is to be 
presumed that the Marlstone must be reached ; in this case the 
Upper Lias clay would be of irregular thickness, being uncon- 
formably overlaid by the Upper Estuarine Series. (See also p. 391.) 
At Bedford County-school, a well was sunk in 1886, in the 
following strata, which are noted on the authority of Mr. 
Cameron : 
Kellaways 
Beds. 
Cornbrash 
Great Oolite 
Clay. 
Gravel - 
f Loamy sand and stone-lumps - 
\ Black clay ... 
(" Limestone ... 
4 Clay .... 
I Limestone ... 
FT. IK. 
8 
17 
8 
}day 
