Sheringham Fossil Hunting

This guide centres on the western lifeboat-station foreshore. A fully measured member-by-member column cannot be assigned to that intermittent exposure from the available published evidence. The account below distinguishes the western foreshore and adjoining Skelding Hill cliffs from the separate eastern Beeston reference section. Published logs permit considerable detail in the western glacial deposits, but not a single continuous Chalk-bed column beneath every beach patch.

Modern beach cover

Mobile sand, shingle and seaweed conceal the rock platform to varying degrees. These are present-day cover, not a fossiliferous bedrock formation, and their removal during scour controls access to the older surface.

Quaternary sediments of the adjoining cliffs

Glacial deposits

Tills, sands and gravels form a structurally complicated succession. The Sheringham Cliffs Formation has its type area along the coast towards West Runton, where it overlies pre-glacial sediments and is overlain by younger outwash deposits. The formation includes several members regionally; listing all of them as a complete vertical sequence beside the western lifeboat station would be misleading.

ALBION GLACIGENIC GROUP

Briton’s Lane Formation

Briton’s Lane Sand and Gravel Member

Flint-rich, bedded sands and coarse gravels occur as younger outwash remnants, including the cap at Skelding Hill. Their erosional relation to older glacial deposits must be distinguished from sand-and-gravel bodies enclosed within the deformed till. The formation’s name is retained for the later outwash; it is not applied to every sorted sediment body simply because that body contains gravel. Regional quarry thicknesses do not measure the cap at Sheringham.

Sheringham Cliffs Formation

Weybourne Town Till Member

A pale, chalk-rich till lies structurally above the brown sandy mélange in the mapped Sheringham–Weybourne cliff section. Phillips and Lee describe a relatively persistent 1–2 m upper till in their study area and correlate it with the Weybourne Town Till. This is a scoped observation from their section, not a thickness guaranteed at the modern lifeboat-station exposure. The chalk-rich diamicton can become interfolded with older sediments, producing repeated pale bands rather than a series of separate deposits.

Bacton Green Till Member and its mélange facies

The brown sandy diamicton has fine compositional banding and contains heavily folded and sheared material. Elongated or eye-shaped sand inclusions are wrapped by the surrounding fabric. Tight folds, thrusts and ductile shear zones record ice-driven deformation, predominantly towards the east in the mapped western section. Some apparent “beds” are therefore tectonically stretched inclusions. The coastal study records a locally thick mélange, reaching about 30 m across the whole study area, but no such maximum is assigned to a particular beach patch.

Enclosed sand-and-gravel channel bodies

Sorted sediment bodies near the top of the mélange have concave, erosive bases and locally retain a cap of sandy or chalk-rich till. Their fills include sand, silty sand and clast-supported gravel, with flint, quartzite, vein quartz and locally reworked chalk and shell material. In the mapped western section these bodies were deformed by the same ice movement as their enclosing till. Phillips and Lee therefore interpret them as part of a subglacial drainage system, not merely later outwash deposited in gravity-driven sag basins. They are sediment bodies within the deformed complex, not newly named formal members.

Logged gravel-rich channel fill near Skelding Hill

The published log at TG 14869 43531, west of the promenade, distinguishes coarse clast-supported gravel, graded gravel-to-sand beds, trough-cross-bedded gravelly sand, and renewed massive gravel containing sand lenses. Alternating finer and coarser packages record changes in discharge and sediment input. The measured channel-fill architecture is local: these facies cannot be matched as continuous beds across the town beach. Nor do broken shells in the gravel establish a marine depositional environment, because older fossil-bearing sediment was scoured and redeposited.

Sand-dominated fills, quiet-water laminae and mass-flow layers

Other mapped bodies contain fine- to medium-grained, ripple-laminated and cross-bedded sand, interrupted by deformed silty-sand layers interpreted as slumps or sediment flows. Thin clay and silt layers record quieter phases between stronger flows. Water-escape structures, load deformation and small faults show that some deformation occurred while the fill was accumulating. The larger bodies contain several cross-cutting channel packages, so their internal sequence becomes younger laterally as well as upwards. These process-defined subdivisions remain separate from the glacial till members.

Dimensions of logged sediment packages. The mapped western-coast study records individual fining- and coarsening-upward packages on a scale of 2–7 m, while smaller channel bodies commonly contain a few sand-and-gravel units each about 1–3 m thick. These dimensions belong to particular logged fills within the 4.4 km study section; they are not a thickness for a named formation, every channel or the chalk beneath the lifeboat station.

Happisburgh Glacigenic Formation

Happisburgh Till Member: discontinuous lower till

The western coastal mapping records an older grey, relatively clay-rich till below the Bacton Green mélange where preserved. It thins westwards and is eventually removed between the younger deformed sediment and Chalk. Consequently, it should be included as a documented local component but not projected as a continuous basal sheet. The 2011 western field account explicitly excludes the Walcott Till from that Sheringham–Weybourne sequence, unlike more complete sections east of Sheringham; the eastern Walcott and Marl Bed stack is not imported here.

Alternative 2017 structural framework

Lowestoft Formation — alternative 2017 framework

Weybourne Diamicton Member — alternative framework

West Runton Mélange Member — alternative framework

Lee and colleagues’ later tectonostratigraphical framework places the chalk-rich Weybourne Diamicton and deformed West Runton Mélange within its Lowestoft Formation scheme. West of Sheringham the mélange encompasses interfolded chalk-rich material as well as sandy diamicton and incorporated older sediment. These headings describe an alternative way of organising the same disrupted succession, not extra members above or below the BGS Lexicon units. Their boundaries are partly structural and cannot be read as a simple sequence of separate climate stages.

Pre-glacial deposits

The Wroxham Crag and associated pre-glacial sediments occur between the Chalk and glacial cover in sections along the adjoining coast. Their presence, thickness and internal divisions vary. Crag fossils and material transported by ice must be kept distinct from fossils originally preserved in the Chalk.

CRAG GROUP

Wroxham Crag Formation

Marine sand and gravel beneath the glacial complex

The mapped western coast retains shelly sands, gravels and finer interbeds between the Chalk and till. The 2013 study reports approximately 1–5 m across its Sheringham–Weybourne study area, with substantial truncation. The sediment supplies shell debris and rounded clasts to younger glacial drainage channels; fossils in those channels are therefore reworked. Older regional schemes call this coastal Crag the marine Mundesley Member. That correlation is not a claim that the glacial Mundesley Sand Member is exposed here.

Laminated sediment and clay-pebble reworking near Skelding Hill

The section towards Skelding Hill contains laminated silty clay above the older shell-bearing Crag. Historical studies assigned it to the Pastonian and recorded reversed magnetic polarity. Erosion of laminated material produced clay clasts and locally conglomeratic horizons within the sands. The published succession can thus preserve more than one pre-glacial environmental episode, but it is neither a uniform marine sand sheet nor the West Runton Freshwater Bed transplanted westwards.

Unconformity on Chalk and incorporated Chalk rafts

The older marine sediments rest on an eroded Chalk surface. The glacial sequence above can contain detached and deformed Chalk bodies; a prominent raft has been documented below the Skelding Hill coastguard lookout. Such transported Chalk is distinct from the underlying bedrock platform. Its position high in the cliff cannot be used to reverse the normal geological ages or to assign all adjacent sediment to the Chalk Group.

CHALK GROUP

WHITE CHALK SUBGROUP

Weybourne–Beeston interval

The coastal Chalk is Campanian. The upper Weybourne Chalk and the overlying Beeston Chalk are separated by the Catton Sponge Bed marker in the regional scheme. The western collection record does not locate its fish material precisely enough to choose one member for every local exposure.

East of the town, below Beeston Hill, the Beeston Chalk is documented as soft white chalk with large flints and inoceramid debris. These eastern exposures provide useful correlation, but their full sequence, thickness or fossil assemblage is not transferred to the western collecting area. Published thickness estimates for the member also differ and are not measurements of the rock presently visible beside the lifeboat station.

Beeston Chalk Member — eastern reference section

Below Beeston Hill east of the town, the documented Beeston Chalk is soft white chalk with irregular large flint seams and concentrated inoceramid debris. Ring-shaped flints are recognisable in bedding-plane view. The member lies above the Catton Sponge Bed; its upper boundary is a hardground identified farther east towards West Runton, so that distant upper boundary is not claimed as exposed beside the western lifeboat station. BGS accounts give different whole-member thickness estimates, reflecting different assembled sections; neither is a local western-beach measurement.

Three Sheringham sponge-bearing horizons and the Catton marker

The Cromer sheet explanation locates three sponge beds on the Sheringham foreshore around TG 1565 4325 and identifies the lowest as the Catton Sponge Bed in the relevant scheme. This provides a real local marker near the Weybourne–Beeston transition. The two higher sponge-bearing horizons should remain undesignated unless their correlation is established; they are not automatically Hardgrounds I and II. Those numbered hardgrounds describe the internal Catton interval in the regional scheme, and are not interchangeable with the count of three coastal sponge beds.

Catton Sponge Bed: boundary definition and omission surfaces

The regional Catton interval contains iron-stained, cemented chalk and hardgrounds, with the upper surface of Hardground II marking the top of the Weybourne Chalk in Wood’s scheme. Such a surface represents interrupted sediment accumulation and seabed cementation. Correlation to the Sheringham sponge-bearing exposure supports the member boundary, but the detailed flint-letter sequence and measured beds of Catton Grove quarry are not transplanted into this coastal guide.

Upper Weybourne Chalk westwards from the boundary

The underlying Campanian interval becomes increasingly hard and nodular upwards and includes strongly developed flints, oysters and omission surfaces. Three informal faunal belts, Weybourne 1–3, are recognised in the wider stratotype succession to the west, but they are not three newly measurable beds at the lifeboat station. A west-beach collection label giving “Weybourne–Beeston Chalk” is therefore retained at that precision when its exact horizon was not recorded.

Reported fish-bearing chalk

The old collecting guide’s “Fish Bed” lacks a verified formal definition or bed-level measured log for this western patch. Fish remains are nonetheless documented locally, including an uncertain skull identification in a west-beach collection. The occurrence is retained as palaeontological evidence, while no extra named unit, fixed thickness or regional correlation is fabricated from that collecting phrase.

Dissolution and cementation

Hard tubular stacks west of Sheringham are associated with solution cavities near the Chalk–Crag boundary. Later research indicates that the cementation cannot simply be attributed to glacial meltwater. The structures modify the older chalk and should be shown as features within or at its upper surface, not as an extra stratigraphical formation.

Scope of the modern geochemical study. The 2009 samples came from TG 12733 43536, roughly midway along the Sheringham–Weybourne coast, where surviving stacks and crusts could be examined. Those observations explain the wider family of structures historically described west of Sheringham; they do not establish that flowstone or the same intact crust is exposed beside the lifeboat station today.

Cemented surface crust and tubular stacks

A hard carbonate-cemented crust occurs discontinuously at the upper Chalk surface beneath the Crag, and was formerly connected laterally with the tubular stacks. The 2009 study describes Crag material and flint pebbles incorporated within the cemented crust, showing that cementation post-dated deposition of the Crag. Detached vase-like remnants preserve parts of former solution features; their present orientation on the beach need not be their original one. They are neither an additional Chalk member nor petrified tree trunks.

Flowstone and the distinction between dissolution and cementation

Calcite flowstone was recorded on an inner stack surface. Geochemical results separate the origin of solution cavities from the later cement that hardened their walls. The features therefore preserve a multi-stage post-Cretaceous history involving dissolution, sediment infill and cementation. Older pre-Crag interpretations of the finished stacks are not retained as established fact, and a glacial origin for some drainage does not mean that all cement precipitated directly from glacial meltwater.

References

BGS Cromer district sheet explanation

BGS Lexicon: Beeston Chalk Member

BGS Lexicon: Sheringham Cliffs Formation

Peake and Hancock (1961), The Upper Cretaceous of Norfolk

Woolhouse, Andrews, Marca-Bell and Dennis (2009), Geochemical constraints on the origin of enigmatic cemented chalks

BGS report OR/22/062: review including the tubular chalk stacks of Sheringham

Phillips and Lee (2011), Sheringham–Weybourne subglacial drainage field guide

Phillips and Lee (2013), Development of a subglacial drainage system: western coastal maps and logs

Lee and colleagues (2004), glacial formations and members

Lee and colleagues (2017), alternative tectonostratigraphical framework

Preece and colleagues (2020), pre-glacial sediments and dating

Jonathan Stewart collection: provenance of west-beach fish material