Shoreham-by-Sea: Geology |
The low lying town of Shoreham-by-Sea is built on level land almost entirely below 7.7 metres (25 feet) above sea level (Ordnance Datum, 3.27 metres* above Chart Datum). (for Shoreham Harbour * to be double checked)
Geography
Geology
SHOREHAM CEMENT WORKS
See
"The Chalk of Sussex and Kent" by Rory N. Mortimore
Beeding Quarry |
Revised:
Coniacian
(88 million years ago) from Shoreham Cement Works. The flints on
the beach are younger Santonian rocks. The Shoreham downs is a zone indicated
by Micraster fossils. The Coniacian
is a stage of the
Late
Cretaceous Epoch. It spans the time between 89.3 ± 1 Ma and
85.8 ± 0.7 Ma (million years ago).
85
million years ago, Cretaceous Period
(144 - 66.4 million years ago): Sussex is covered by a warm sea inhabited
by ammonites, Micraster
and other urchins, molluscs, at a lower latitude (Continental Drift: Tectonic
Plate Theory). Sedimentary deposits of foraminiferans such as Globigerina
and coccoliths (microscopic plankton with a calcium carbonate shell) lay
down the chalk (Pic) which is rock of the
South Downs near Shoreham.
Fossil
bivalve Spondylus spinosa (pic).
60 million years ago, Tertiary (66.4 million - 2.3 million years ago). Sussex is alternately covered by sea and tropical deltas.
29
April 2020
Sea Urchin Fossil, Echinocorys sp., from Brooklands beach, east Worthing. Photograph by June Bratton |
25 March 2020
Fossil from Shoreham Beach
Alert children's eyes spotted this very small flint fossil amongst the billions of other pebbles on Shoreham Beach (by Beach Green). It is a bivalve mollusc from the Cretaceous period and the Natural History Museum suggested it could be the bivalve Limatula with representatives still extant today.
PS:
A very nice flint cast of a bivalve called Neithia
from
the Cretaceous chalk circa 85 million years ago.
Hi
Andy
I'm
replying as resident geologist!
Schloenbachia
varians comes from the Cenomanian, Lower Chalk of the Cretaceous Period.
It is found commonly throughout the Lower Chalk of England and Northern
Ireland though rare in Yorkshire. If this is not enough, please get back
to me.
John
Cooper
______________________________________________________________
Booth
Museum of Natural History, 194 Dyke Road BRIGHTON BN1 5AA U.K.
John
A. Cooper, Visitor Services Manager (Natural Sciences)
Large ammonite Acanthoceras rhotomagense 8 ft deep Upper Beeding (this is from the Upper Cretaceous, mid-Cenomanian, earlier deposits).
5
June 2004
ADUR WORLD OCEANS
DAY
The most interesting discovery was an unidentified fossil found on Shoreham beach and brought in by a young girl. This is illustrated above..
The fossil is part of a test (internal shell) of a sea urchin formed about 85 million years ago. The long spines have broken off leaving the base only. The exact species has not been established yet.
It
could be Prionocidaris vendocinensis
but
there are other species it could be as well.
The flint probably formed from the dissolved remains of ancient sponge siliceous spicules and was deposited at a later date into gaps and beds in the chalk when the silica then solidified. When the friable chalk was eroded the flint remained, subsequently rounded into spherical and ovoid pebbles by the action of the waves grinding the pebbles against each other.
Longshore
Drift
Adur
Valley Nature Notes
The Albian Gault Clay, black
and grey clays, contains a diverse marine fauna including ammonites and
molluscs (incl. Spondylus),
ichthyosaurs etc.
Paludina
Limestone is known as Sussex Marble. These are the little white outcrops
amongst the Weald Clay.
Reading Beds form small outcrops of gravelly soil. Raised beaches of flint occur in some areas, e.g. Botolphs.
Brickearth
The Lower Greensand is like a hard chalk and is also known as Malmstone. It is better for crops than chalk.
Link to the Old River Adur Course in Medieval Times
Geology of Brighton to Worthing
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Sussex
Archaeological Society
(Link
to) Cornwall (Prehistory, Geomorphology, etc.)
|
Adur Valley |
malm | mm | n. & v. [OE mealm-
(in mealmstan) = ON malr ore, metal, Goth. malma sand, f. Gmc base also
of MEAL n.1] A n. 1 (More fully malm rock, malmstone) a soft friable rock
consisting largely of chalky material; light loamy soil formed by the disintegration
of this rock. OE. 2 More fully malm-brick. A fine-quality brick made
orig. from malm, marl, or similar chalky clay. E19. B v.t. 1 Treat
(land) with malm. Only in E17. 2 Convert (clay) into artificial malm for
brick-making; cover (brick earth) with artificial malm. M19.malmy a. of
a loamy character L17.
---------------------------------------------------------
Excerpted from The Oxford Interactive Encyclopedia
Developed by The Learning Company, Inc. Copyright (c) 1997 TLC Properties
Inc.
Geology of London
The geologic foundation. The landscape of southeastern England is shaped
by an undulating bed of thick white chalk, consisting of a pure limestone
speckled with flint nodules in the upper beds. Under the chalk are an incomplete
layer of Upper Greensand (a Cretaceous rock; 66.4 to 144 million years
old) and a 200-foot- (60-metre-) thick waterproof layer of Gault clay.
Beneath them in turn lies London's true geologic foundation, a stable platform
of old hard rocks of Paleozoic age (about 245 to 540 million years old).
This basement is buried nearly 1,000 feet below London, sloping away southward
to depths more than 3,300 feet below the English Channel.
The London Basin is a wedge-shaped declivity bounded to the south by
the chalk of North Downs, running north to south, and to the north by the
chalk outcrop of the Chiltern Hills, running up in a northeasterly direction
from the Goring Gap. The chalk floor of the basin carries a sequence of
clays and sands of the Tertiary Period (those 1.6 to 66.4 million years
old), chiefly the stiff, gray-blue London Clay, which lies up to 433 feet
thick under the metropolis and supports most of its tunnels and deeper
foundations. The subsoil is topped with deposits of gravel up to 33 feet
deep, consisting mostly of pebbles with flint, quartz, and quartzite. There
are also patchy deposits of brick-earth, a mixture of clay and sand often
excavated for building materials. Lastly, modern London is built on "made
ground," the deposits of centuries of continuous human occupation, which
have accumulated on average between 10 and 16 feet in the oldest urban
nuclei of the City and Westminster.
In England the Aptian Stage is represented by part of the Lower Greensand formation.
Excerpted from Encylopaedia Britannica CD-ROM 1997.