GREAT OOLITE SERIES : TOWCESTER. 397 
Towcester to Stoic t-nine- Churches. 
Referring to the country around Towcester, Mr. Aveline has 
remarked on tho unconformity between the Great Oolite and the 
Northampton Sand, observing that "the superior formation lies 
indifferently on higher or lower beds of tho inferior formation, 
indeed sometimes the Northampton Sand is entirely overlapped 
by the Great Oolite, the latter resting on the Upper Lias Clay."* 
There is no doubt that the Northampton Sand becomes very 
thin in that neighbourhood and along the borders of the Tove 
Valley and Castlethorpe, but we have evidence at Deanshanger, 
near Stony Stratford, that Upper Estnarine Clays as well as 
Northampton Sand intervene between the base of the Great 
Oolite and the Upper Lias. The same is probably the case, so far 
as regards the Upper Estuarine Series, in those areas of the Tove 
and Nene valleys, where the Great Oolite is shown, on the 
Geological Survey Map, to rest directly on Upper Lias Clay. I 
am informed (1892) by Mr. Beeby Thompson, that Upper Lias 
Clay lias been opened up in the brickyard at Grafton Regis ; that 
it is " capped by some whitish sand with much argillaceous 
matter, which represents, no doubt, the Northampton Sand of this 
district." 
Quarries have been opened in various places to obtain material 
for lime-burning, aixd for local building-purposes or road-metal ; 
but a number of those marked on the Geological Survey Map 
are now closed. Among the openings, there are those west of 
Sulgrave, near Culworth, east of Weedon Lois, and south-east of 
Maidford. At the Maidford lime-kiln the following section was 
to be seen (Fig. Ill): 
FT. IN. 
r~3. Boulder clay, gravel and loamy 
m ' i n 'ff J sand, with disturbed and contorted 
masses of Great Oolite Clay and 
I rubble - - 6 to 8 
f2. Greenish rubbly stone, with Ostrea~\ 
Grea i Oolite I 1. Pale limestones with scattered grains I -.^ n 
Limestone. of oolite, and with bands of marl f" 
I and clay - - -J 
A deeper section, showing 16 feet of the beds, was recorded by 
Mr. Aveline, who notes the occurrence of Nerincea, Pholadomya 
Heraulti, Trigonia, and a band with Corals. 
On Grimscot Hill, north of Grimscot, and north-east of Cold 
Higham, a small area of " Forest Marble," observed by R. Trench, 
was marked on the Geological Survey Map.f This outlier is of 
interest in connection with the section near Stowe -nine-Churches. 
A- specimen of Nautilus obesus ? is recorded from Litchborough, 
probably from the Great Oolite Series.f 
* Aveline and Trench, Geol. part of Northamptonshire, p. 11; see also Judd, 
Geol. Rutland, p. 31. 
f Aveline and Trench, Geol. part of Northamptonshire, p. 13. 
j Foord, Cat. Fossil Cephalopoda, Brit. Mus., Part 2, p. 218. 
