KGG Field Meeting to Herne Bay.
Saturday 25th June 2011

The foreshore and cliffs east of Herne Bay with the towers of St Mary's church, Reculver in the background

On a bright sunny day seventeen of us, KGG members, friends and colleagues of Dr Adrian Rundle from the Natural History Museum, met Adrian at Herne Bay for a field meeting. Our intention was to study the geology of the Palaeocene and Eocene rocks exposed in the cliff faces and on the foreshore between Herne Bay and Reculver to the east (see the picture left with the towers of St Mary's Church, Reculver on the skyline).

These rocks were deposited between fifty two and sixty million years ago, when the area was beneath a shallow sea and several degrees nearer to the equator. They range from coarse grain sands to fine clay.

Starting from the oldest and lowest beds the exposed formations are the Thanet Sand Formation, the Upnor Formation, the Oldhaven Formation and the London Clay Formation.

Topping these formations are recent Brickearth (wind blown) and other drift deposits. Though described as 'rocks' the cliffs still comprise loosely consolidated deposits that make them unstable and subject to serious erosion. The Oldhaven, Upnor and Thanet Sand Formations all sit unconformably on earlier deposits as other formations in the sequence are either absent or have been eroded away.

Some of the group in Bishopstone Glen

Adrian had planned the field trip well. Starting at 10.30am with high tide at 8.02am and low tide at 1.55pm we had about three and a half hours of receding tide - plenty of time to do all that we wanted.

Our first stop was Bishopstone Glen (see picture right), a cleft running back into the cliff, where the sequence from Thanet Sand Formation to London clay was visible. The Thanet Sand is above beach level but is mostly obscured by material from cliff falls and sea defence works. This site is of international importance and protected. Climbing or digging the faces is prohibited.

Studying a small sample of grey sand with a lens showed that it consisted of sharp, glassy grains with dark green/black specks. The glassy grains were quartz and the dark specks were glauconite. Glauconite is an iron/potassium silicate formed by chemical and biological alteration of iron-rich micas in slowly depositing sediments. It is indicative of a continental shelf environment. Glauconite is the mineral that gives the Wealden Greensand its colour and name.

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Further up the cliff face were several burrows made by solitary bees. Adrian explained that these bees paralyse their prey before carrying it into the burrow. The bee then lays eggs on its victim before sealing it up in a nursery/tomb!

Large blocks of Norwegian larvikite protect the fragile cliffs from erosion by the sea.

From the Glen we moved eastwards towards Reculver, noting the exposed strata as we did so. The cliffs are constantly being eroded, partly by waves under-cutting the soft sandstone and partly by water filtering down through the cliffs and washing out the less consolidated sediments. Large blocks of Norwegian Larvikite have been placed at the top of the foreshore to reduce wave erosion of the cliffs (see picture left).

The stratigraphy here was defined by D. J. Ward in 1978 (see references below). Ward divided the formations into sixteen units, the Thanet Sand Formation - units A (oldest) to I, the Upnor Formation - units J and K, the Oldhaven Formation - units L to N, and the London Clay Formation - units O and P.

It is very difficult to identify these units from the foot of the cliffs, but helpful clues allow one to trace the major formations.

The lowermost Thanet Sand Formation is mostly glauconitic grey-green silty sand. The easiest to identify is bed 'B' that consists mainly of large flat tabular nodules. These are best seen towards the Reculver end of the beach where the tablets project outwards from the cliff face. Most of the other beds are defined by the fossils they contain viz.,Artica eutylus cuneatus (A), Artica morrisi (C), Panopea remensis (D), Astarte tenera (E), Tornatellaea parisiensis (F), and Corbula regulbiensis (G). Some readers may be interested to know that 'regulbiensis' means 'of Regulbium', Regulbium being the Roman name for the place we know today as Reculver.

The top of the Thanet Sand is perhaps most easily identified by the lower bed (J) of the Upnor Formation that lies above it. Known as the Beltinge Fish Bed, this is a dark silty clay with rounded black pebbles and numerous sharks' teeth.

The division between the Upnor and Oldhaven Formations may be identified by the Oldhaven Basal Pebble Bed (Unit L). This unit comprises small rounded black flint pebbles in a sandy matrix. The pebble bed is very distinct, where it occurs, and may be traced along much of the cliff face.

Some time was spent looking for fossils and selenite crystals in the fallen scree at the foot of the cliffs. Before lunch the party examined the Artica morrisi Bed and Artica eutylus cuneatus Bed on the foreshore. Samples of the latter were collected for the microfossils.

The party then had lunch sitting on some rock tablets before making its way back along the beach. A further look at the Artica morrisi Bed in its scattered exposures on the foreshore towards Herne Bay yielded pyritic internal moulds of some of the bivalves. Samples of Recent fine shelly sand concentrated next to the groins were collected for foraminifera etc. We ended up on the pebble spit, that is exposed at low tide, on which sharks' teeth derived from the Beltinge Fish Bed can be found. Looking for sharks' teeth proved to be a popular pastime.

A few pictures of the group's activities are shown below:-

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A bed of bivalves in the cliff face, mostly badly eroded and very fragile Large tablets of sandstone eroded from the Thanet Sand formed a comfortable seat to have our packed lunch
A lens of bivalves in the Oldhaven Formation in the cliff face, mostly badly eroded and very fragile
Large tablets of sandstone washed out of, or eroded from, the Thanet Sand Formation
Some members searching for fossils and selenite crystals in the scree at the foot of the cliffs A small group of members among the seaweed-covered rocks on the foreshore
Some members of the group searched for fossils in the scree at the foot of the cliffs...
While others preferred to get muddy on the foreshore

More pictures

For more pictures of the field trip click here
All pictures were taken by Stephen Taylor

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There is a fast, half hourly train service from London Victoria to Ramsgate and Dover Priory that stops at Herne Bay. The train divides at Faversham; usually the front four coaches go to Ramsgate (via Herne Bay) and the rest of the train continues to Canterbury and Dover. Be sure to travel in the correct portion of the train or you could end up in Dover! From the station, follow the visitor signs to 'The Seaside' until you come to the concrete promenade. An easy, flat, one and a half miles walk takes you to the end of the promenade and the start of the geological exposures.

If travelling by car, there is a car park at the end of Reculver Drive (O/S grid ref: TR 205686) with a concrete path leading down to the end of the promenade. Alternatively, one may park at Reculver (where there is a visitor centre and restaurant serving hot meals) and walk across the downs or descend to the beach to approach the geological site from the east - a pleasant walk if the weather is fine!


Tides can make sea coasts dangerous. Never walk along a seashore without first checking the times of high and low tides. Always allow ample time for the journey, including extra time for unforeseen emergencies.

Seaweed on the foreshore rocks makes them very slippery and may conceal uneven surfaces. Steps covered with wet clay will also be very slippery.


WARD D.J. 1978: The Lower London Tertiary (Palaeocene) succession at Herne Bay, Kent. Report of the Institute of Geological Sciences, No.78/10, 12 pages, 1 figure, 1 map.

DOWNER Geoff. 2011: The Geology of Reculver Country Park. Published by GeoConservation Kent (formerly Kent RIGS), 53 pages, many photographs, maps and figures, in colour.

PITCHER W.S. 1967:Itinerary VII, North Kent Coast - Herne Bay.
In PITCHER W.S., PEAKE N.B., CARRECK J.N., KIRKALDY J.F. and HANCOCK J.M. Geologists' AssociationGuides No.30B

RAYNER David, MITCHELL Tony, RAYNER Martin, and CLOUTER Fred.: London Clay Fossils of Kent and Essex. Published by the Medway Fossil and Mineral Society, 228 pages, 1270 photographs and 265 named species.