Page:Quarterly Journal of the Geological Society of London, vol. 29.djvu/288

 ampton Section, there separate the Great Oolite Limestone from those lower beds.

About three miles to the south of the Harrington area, and half a mile due east of the village of Old, is a .small narrow strip of the Lincolnshire Limestone, only worthy of mention as being the most southerly point at which the presence of that Limestone has been detected.

Kettering.

At about a mile due east of Kettering, the eastern escarpment of the valley of the small river Ise presents this section : —

Great Oolite Limestone.

Upper Estuarine Series.

Lower Estuarine Series,

Ferruginous Beds, Northampton Sand.

Upper Lias Clay.

This sequence (with the occasional superaddition of the Great Oolite Clay) is continued due east, right across the county to the Nene valley (a distance of 6 miles), and, with the further super- additions successively of Cornbrash, Kelloway Rock, and Oxford Clay, some three miles further still, to the boundary of Northampton- shire, and so on beyond, into Huntingdonshire.

Upon the outcrop of the same escarpment, at a point near Kettering Mill, and a very little north of the last-mentioned section, we find, as it were, the thin end of the wedge of the Lincolnshire Limestone coming in; and this section, and for the first time, is presented : —

Great Oolite Limestone.

Upper Estuarine Series.

LINCOLNSHIRE LIMESTONE (very thin).

Lower Estuarine Series,

Northampton Sand.

Ferruginous Beds,

Upper Lias Clay.

Upon the summit of the escarpment, upon the opposite or western side of the Ise valley (which here is about three quarters of a mile wide), and at about three quarters of a mile north-east of Kettering, the Lincolnshire Limestone, with a slightly increased thickness, again occurs, and at a little distance to the north is surmounted by the Upper Estuarine beds.

It is clear that at this point we cannot be very far off the original line of the thinning out of the Lincolnshire Limestone, and that we have touched upon the main continent (so to speak) of that formation, from which the Ise valley has here severed a portion of the southern margin ; for, as the valley of the Ise trends northwards, the thin band exposed by the escarpment both thickens and spreads.

Leicestershire.

From the point of its first appearance near Kettering, the formation extends for six miles in a north-westerly direction towards Leicestershire ; in which county is a small outlier between Medbourne and Holt.