GREAT OOLITE SEEIES : OUNDLE. 
411 
Great Oolite 
Limestone. 
White, marly limestone, full of shells, 
Modiola imbricata, Ostrea subrugu- 
losa, Pholadomya deltoidea, Pter- 
operna plana, Myacites decurtatus, 
Oardiuvn ... 
Beds of hard (" Forest-Marble-like ") 
stone, composed of comminuted 
shells, in two courses, with a clay- 
band between them. In other places 
this clay-band increases to a thick 
bed of white marl, full of oysters 
and other shells - 
Bed of white marl, becoming, in 
places, hard and nodular, and con- 
taining shells ... 
FT. IN. 
7 
Prof. Judd remarks that the Great Oolite Clay includes beds 
of more or less sandy clay, and in some places the strata are 
" crowded with carbonaceous markings." 
The following section at Oundle was recorded by S. Sharp* : 
"Lime Earth": cream-coloured ar- 
gillaceous bed, sometimes used for 
mortar, without burning 
" Pendle " : Hard flaggy stone, with 
Modiola, imbricata - 
Blue clay - 
Marl with Osirea Sowerbyi : burnt for 
lime ----- 
FT. IN. 
2 
Great Oolite , Hard ghell limestones 
Limestone. -- 
Best Building Stone : Hard blue- 
hearted limestone, full of commi- 
nuted shells ; stone worked into lin- 
tels and window-sills, &c. - - 3 
Marly limestone, full of shells - 3 
Hard blue-hearted limestone, full of 
comminuted shells, Pteroperna, &c. : 
stone used for road-metal - - 2 6 
Upper Estuarine Series. 
From these beds the Star-fish, Ophiurella Griesbachi was 
obtained ; and Sharp notes also the occurrence of Belemnites 
(small specimens), fossils which are exceedingly rare, as a rule, 
in the Great Oolite. Many other species have been obtained at 
Oundle, at Wadenhoe, and other localities. 
Prof. Judd estimated the thickness of the Great Oolite Lime- 
stone at 15 feet, and the Great Oolite Clay at 6 feet, near 
Wadenhoe and Pilton.f Near Oundle the thickness of the Clay 
is about 15 feet. 
He mentions that in the valleys west of Oundle, the oyster- 
beds and underlying ragstone of the Great Oolite Lime- 
stone are exposed in a number of pits. The former beds are 
known locally as "hurr," and are often dug for constructing 
artificial rock-work. "Where covered by ferruginous gravel (de- 
rived from the Northampton Sand), these beda have often acquired, 
* Quart. Journ., Geol. Soc., vol. xxix. p. 280. 
f Geol. Rutland, p. 216. 
