1870. ] " SHARP—NORTHAMPTONSHIRE OOLITES. 369 
Area III. Dusron. 
The parish of Duston lies immediately west of Northampton, from 
which it is separated by the river and valley of the Nen. Its highest 
ground is capped with Great Oolite Limestone, A, which is quarried 
at Hopping Hill (q), about two miles N.W. of Northampton, on the 
Dunchurch road, and extends from that point in an irregular band 
for about a mile and a half nearly due west. 
At about three-quarters of a mile N.E. of q, a nearly circular 
patch of this limestone, about a quarter of a mile in diameter, occurs 
upon the opposite high ground of the Dallington lordship (r), a deep 
valley and the Dallington brook intervening. 
At about half-a-mile 8. of g, another patch is quarried ats. This 
is on a somewhat lower level, having been let down in the fork of a 
double fault, marked in the map of the Survey. 
At Hopping Hill (q), the limestone pit presents a section of about 
12 feet elevation, the fossils obtained being in the bulk identical with 
those found in the Kingsthorpe limestone, the exception being that 
Pholadomya lyrata and P. Heraulti, forms not common at Kings- 
thorpe, are here very abundant. The earthy shale-bed (‘ Dirt 
Bed”) of Kingsthorpe is also present, but nearer the base than in 
the former section. 
Section of Limestone A at Hopping Hill. 
HU Soto clay like) Marl iste ns sscescersert.ceetinses otteeesccaesteesa.ccemeuen Ake 2 0 
2. Soft marly rock, in three layers of varying hardness, containing 
Pholadomya lyrata and P. Heraulti, &C. .........ccececees 1 6to 2 0 
3. Band of soft marl, very full of shells..........00...00ccececececsceseees 0 9 
4. Hard marly rock, with few shells .................ceeecesscseeceeceeceerees i @ 
5. Compact arenaceous stone, somewhat calcareous, with few shells, 
OSECHCOSTALOMCO ERE en NAY ae Sa gi NE) aA i 3 
6. Earthy shale-bed (‘ dirt-bed ”’) in thin layers, containing flattened 
ibovallvyesichietly <Osinea) sterner. Mina sccscbicdcusencomacotee scfcde sane 1 O 
7. Ditto, more argillaceous, and paler and greyer in colour ............ 1 O 
8. Very hard limestone, with blue heart, Rhynchonella concinna &e.... 1 6 
9. Soft limestone, very full of shells, Rhynchonella concinna, Modiola 
imbricata, Natica various species, large Nautili, Clypeus, &e. ... 1 6 
Blue brick-clay at base. 
At t, a little more than a furlong N.W. of the limestone-pit g, and 
on the N.W. incline of Hopping Hill, the underlying blue clay B is 
worked for bricks. It is here about 8 feet thick: at the top of the 
section is seen its junction with the overlying bottom soft bed of the 
limestone, and at the base the characteristic ferruginous band ob- 
servable in the two former areas. This clay has occasional bitumi- 
nous and woody bands and patches, but has yielded no other fossils. 
In the same brick-field, within a very few yards, the underlying 
white sand C is dug to a depth of about 6 feet, but has not been 
bottomed. I have not found here the plant-bed, which probably 
has not been reached. 
This sand forms the surface-bed over a considerably area of the 
opposite high ground to the N. and N.W., constituting the Dallington 
and Harlestone Heaths. 
