

Remarks on the Inferior Oolite and Lias in parts of Northampton- 

 shire, compared with the same Formations in Gloucestershire. 

 By the Rev. P. B. BRODIE, M.A., F.G.S. 



HAVING, at a late meeting of the Cotteswold Naturalists' Club, 

 given a vivd voce account of the Inferior Oolite and Lias in a 

 part of Northamptonshire; at the request of the Secretary, I 

 have prepared a more detailed description for our ' Proceedings/ 

 It is well known that certain beds in the Inferior Oolite in the 

 neighbourhood of Northampton have been extensively worked 

 for the ironstone which largely prevails in it thereabouts, though 

 I believe it is not now so generally used for (economical pur- 

 poses as it was formerly. This was certainly the case with 

 those quarries which I examined near Blisworth. They are not 

 worked to any great depth, and occupy the higher ground in the 

 district ; the strata consist of sandy ferruginous oolitic stone 

 containing a few imperfect casts of shells, though the greater 

 part of the mass is unfossiliferous : the top beds are coarse, and 

 contain impressions of shells; the lower ones are more com- 

 pact, and are composed chiefly of ironstone. The Inferior Oolite 

 here appears to be of no great thickness, and differs materially 

 from that of the Cotteswolds. The hills which are occupied by 

 it near Blisworth are comparatively low, and form a striking 

 contrast to those in Gloucestershire partly composed of the same 

 formation. The fossils I obtained were a large Cardium, a Tri- 

 ffonia, a Pecten, Terebratulce, and a few Univalves. Fossils are 

 much more abundant at Northampton, though only occurring 

 there in the form of casts. 



Upper Lias. From the position of the Inferior Oolite, the 

 Upper Lias was to be looked for at a low level at the base of 

 these hills, and I accordingly found it in a brick-pit in the 

 valley at Bugbrook between Weedon and Blisworth, below 

 the level of the Railway at no great distance from the Kilsby 

 tunnel. Beds of Lias clay and shale are used for brick-making 

 with the usual Upper Lias fossils, among which Ammonites 

 serpentinus and Belemnites were very prevalent. The clay is 

 traversed by a thin, continuous layer of limestone, which, as 

 1 anticipated, turned out to be the ' fish bed/ identical litholo- 

 gically with the same band in Gloucestershire, and full of innu- 

 merable fragments of fish (though I could discover none entire) 

 and coprolites, with some specimens of Inoceramus dubius and 

 t races of Sepia. 



