File:The Quarterly journal of the Geological Society of London (13365363203).jpg

1850.. PRESTWICH ON THE LOWER TERTIARY STRATA.
257
Fig. 2*. — Section at Clarendon Hill.
s.
a, Ochreous flint gravel.
b. liondon clay ; dark bluish grey sandy clays with nume-
rous PanopcscB, OstrecB, and Finnce.
Cc. Large tabular masses ; composed, some of almost
I a pure green sand, and others of a coarse ochreous
N sand, with a calcareous cement. A few rather
small round flint pebbles are scattered through
L these blocks.
d. Alternating thin beds of sand and thick beds of
mottled clay ; chiefly red.
The chalk outcrops lower down the hill at a depth apparently of
ahout forty to fifty feet beneath "c."
Organic remains of stratum "c," at Clarendon Hill.
Buccinum (.' ambiguura, Desk.).
, n. sp., large and globose.
Cancellaria Iseviuscula, Desk.
Cardiura nitens, Sow.
, n. sp., a.
Corbula longirostris, Desk.
Cytherea obliqua, Desk.
ovalis, var. ?, Sow.
laevigata, var. a ?, Lamk.
Ditrupa plana, Sow. sp.
Fusus tuberosus, Sow.
, n. sp., witb plain costse.
, n. sp., large and smooth.
Natica glaucinoides, Sov).
Hantoniensis, Pilk.
Nucula, a small species.
Ostrea, large undetermined species.
Pectimculus brevirostris, Sow.
Plumsteadiensis, Sow.
Pyrula tricostata. Desk.
Pleurotoma comma. Sow.
Rostellaria Sowerbyi, Mant.
Tellina.
Turritella ?
Teeth of Lamnae.
Carbonized pieces of wood.
The fossils are extremely abundant, and occur in large blocks of
clay and green sand with a calcareous cement. The most common
species are the Ditrupa plana, Natica glaucinoides and N. Hanto-
niensis, Cytherea obliqua, Pectunculus brevirostris, Rostellaria Sow-
erbyi, and Fyrula tricostata.
It is not my intention to trace this bed any further in Hampshire :
I may however observe, that I there know of no other good section
of it. I have seen it, but not well exhibited, at Padnell, in Bere
Forest, and also on the railway near Fareham.
Crossing the intervening chalk district to the most westerly ex-
tension of the London tertiaries, the first point, where we meet with
some uncertain indications, without sections, of the basement bed of
the London clay, is, capping the summit of Bagshot Hill between
Great Bedwin and Hungerford. It is better exposed between Hunger-
ford and Newbury, near the summit of Pebble Hill, one mile south
of Kintbury. (See fig. 3.)

• This and the following sections (figs. 2 to 20) are all drawn upon the same
  

scale ; viz. 1 inch represents a thickness of 20 feet. Section fig. 1 is an exception
to the rule. It is the fig. given in the Journal of the Society, vol. iii. p. 362, and
is upon a much larger scale.