184 LOWER OOLITIC BOOKS OF ENGLAND : 
FT. IN. 
{Soft white and ferruginous Bands, shaly 
in places - - about 10 
Pale and yellow (ferruginous) sand- 
rock - - - - - 9 
The sand-rock hardens on exposure in dry weather and with heat, but 
crumbles with moisture. It has been used as a building-stone in Kings- 
thorpe, and also in Northampton in some of the old buildings (Union 
Infirmary, Barrack wall, &c.). About 16 cubic feet weigh 1 ton. It is 
not however a very durable stone, and is seldom used now for building- 
purposes. 
It was formerly sent away for building furnaces. The sand is now 
employed for making mortar, while the white sand is sold for scouring 
purposes, for kitchen floors, farm utensils, and stables. 
The section was evidently somewhat different when described 
by Sharp. The main mass of the white stone was then obtained 
from the upper portion of the series, and he observed a plant-bed 
with vertical rootlets near its base, and above the yellow (or brown) 
sandstone. He noted also a similar section near the Stand on the 
Eace-course at Northampton.* (See Fig. 48, p. 169.) 
The junction of the Northampton Beds with the Upper Lias 
clay was well shown in the railway (Towcester line) near Blis- 
worth. At the base of the Ironstone-beds, nodules or pebbles of 
argillaceous ironstone occur ; and lower down there is another 
band (3 or 4 inches thick) with similar rolled nodules, some of 
them bored. The section is as follows : 
FT. IN. 
flronstone-beds, frith nodules at base 
10 Oor 12 
Northampton J Greenish clayey sand, with veins of 
Sand. | iron-ore - - 2 
: Band of clay, with nodules ; some 
[_ bored - 3 to 4 
Upper Lias - Grey clay. 
Lithologically we seem here to have a kind of passage upwards 
from the Upper Lias clays to the Ironstone of the Northampton 
Beds : but on the whole the evidence favours the view that there 
has been some destruction of the Upper Lias clay, materials from 
which are incorporated in the basement-beds of the Northampton 
Sand (see also p. 1 68). The overlying Lower Estuarine Beds, 
&c. were shown at the Blisworth Ironstone-pit. f 
In the Kingsthorpe brick-pit the junction of the beds was also 
shown, and there above the Upper Lias we have 6 to 8 feet of 
rubbly brown sandstone and ironstone, with pebbles and rolled 
nodules.J 
Along the Nene valley, between Northampton and Thrapston, 
as pointed out by Prof. Judd, the Lower Oolites are cut through, 
and the streams flow over the Upper Lias clay. The Northampton 
Sand, which is thin along the outcrop, forms the only representa- 
tive of the Inferior Oolite in this tract as far as Oundle, for the 
* Quart. Journ. Geol. Soc.,vol. xxvi. pp. 362, 165. 
t Sharp, Quart. Journ. Geol. Soc., vol. xxvi. p. 379. 
j Sharp, Ibid., p. 3fi<5. 
