TRANSACTIONS
OF THE
HULL
GEOLOG ICAL
SOCIETY
ABSTRACTS OF
LECTURES.
November I5th,
1894.
ADDITIONAL NOTES
ON THE HESSLE GRAVELS,
BY F. F. WALTON,
F.G.S.
Vide paper on
"Some new sections in the Hessle gravels" by F. F. WALTON, F.G.S., in
Proceedings of the Yorkshire Geological and Polytechnic Society. New Series.
Vol. XII. Part V. P. 396.
These sections
are exposed by the quarrying of gravel and sand in a field between
Southfield and the Ferriby road and adjoining Woodfield Lane, Hessle. The
gravel is in layers of varying thickness, separated by beds of sand, and is
contorted in places but generally inclining towards the ancient Chalk Cliff,
and is composed of chalk and flint fragments, usually of small size but the
flints are occasionally as large as 3 in. cube, both are angular and are not
water-worn. The sand is composed principally of clean rounded grains, and is
similar to that from Sewerby cliff. These layers and the ancient Chalk Cliff
itself are covered with the Hessle Boulder Clay, averaging about 4 feet in
thickness, the under surface of which is very uneven and filling up hollows
apparently left in the gravels by the melting of ice or other glacial
action. The general characteristic of these gravels appear to me to suggest
that they are of the same age as the pre-glacial deposits banked up against
the buried Cliff at Sewerby.
During the year
1895 extensive excavations have been carried on in these gravels, in the
large pit at Southfield, Hessle; especially in a North and North Westerly
direction. So far the greatest depth reached is about thirty feet, although
the average depth is about twenty-five feet.
A trial pit has
recently been commenced near the edge of the pre-glacial cliff of
Holderness, going down for about twelve feet almost entirely through sandy
gravel, the bedding of which lies against the cliff at an angle of about
45°. The gravel in this pit, nearest the chalk face, contains a large
proportion of fairly large flints, and is also much more firmly cemented
together. The boulder clay above this thins off considerably; the lower
portion being irregular and showing a lenticular patch of sand between it
and the gravel.
Three other
trial pits have been made, a little to the North of the large pit, which
extend in a line from West to East. The western most one is dug through
sandy gravel with much chalk and flint; the flints are large some of them
being over a foot in length. From the appearance of the gravel here the
excavation must be near the Chalk Cliff. The middle pit, which is about
twelve feet deep, is much more sandy and there are no large flints. The
third and most easterly passes through about twelve feet of clean sand;
there being no gravel in it. With the exception of the lower jaw of a horse,
no bones have been found in the gravel for some time; though numerous
additions have been made to the list which appears in the paper already
referred to. Up to the present, remains of the following animals have been
found in these gravels: Equus
caballus (Horse) Bos primigenius
(Urns) Cervus sp ? (Deer).
No foreign
pebbles, with the exception of one or two small quartzites, have been found
in these gravels until quite recently (March, 1896) when in the northwest
corner of the pit at a depth of twenty-three feet about forty water-worn
pebbles have been dug up; these consist of quartzites, basalt, sandstones,
etc., the relative proportion being shewn in the following table:-
|
|
No.
found. |
|
|
Quartzite |
16 |
40 per
cent. |
|
Basalt |
6 |
15 per
cent. |
|
Secondary Sandstone |
1 |
2.5 per
cent. |
|
Sandstones |
4 |
10 per
cent. |
|
Igneous |
7 |
17.5 per
cent. |
|
Water-worn flint |
1 |
2.5 per
cent. |
|
Uncertain |
5 |
12.5 per
cent. |
|
total |
40 |
|
These pebbles,
which were found within a small area vary from one to three inches in
diameter and are distinctly water-worn. They exhibit no evidence of ice
action and in shape are identical with ordinary beach pebbles.
The photograph
kindly taken for the Society by Mr F. Appleyard, shows the layer of boulder
clay overlying the gravel and containing many far-travelled stones in
addition to those from the immediate neighbourhood. Beneath the boulder clay
is the gravel and sand known as the Hessle gravels, the upper portion being
disturbed and contorted by the action of the ice which deposited the boulder
clay. It is in this gravel and sand that the mammalian remains are found.
The boulder
clay covering the gravels is that known as the Hessle Clay and is the
uppermost of the boulder clays found in Holderness. It follows therefore
that the animals whose remains are found in the gravels must have existed in
this district at the very latest before the last boulder clay of the Glacial
Period was deposited. They were probably deposited here some considerable
time before they were covered by the boulder clay, but the evidence on this
point is not yet complete.
The thanks of the Society are due to Mr. Cook, the owner of the pits, for
the facilities he has afforded for the investigation of these gravels.
Copyright Hull Geological Society 2016