Charmouth (Black Ven) Fossil Hunting

1811–1812 – Joseph and Mary Anning’s first major ichthyosaur discovery
Joseph Anning found the skull in 1811, and Mary Anning returned to the same site and excavated the rest of the skeleton in 1812. By early 1813 it had become the first largely complete ichthyosaur to be uncovered and scientifically studied, helping transform understanding of extinction and ancient life.

1814 – Mary Anning’s ichthyosaur entered the scientific literature
After its excavation, the specimen was studied by Sir Everard Home and became one of the fossil discoveries that brought ichthyosaurs to the attention of the scientific world. This was one of the most important early scientific milestones for the Charmouth–Lyme coast.

1820 – the Anning ichthyosaur was recognised as an extinct marine reptile
By 1820 the strange animal found by the Annings had been recognised as an extinct marine reptile rather than a crocodile or fish. This was a major change in interpretation and part of the wider scientific impact of the Charmouth coast discoveries.

1823 – Mary Anning discovered the first complete Plesiosaurus skeleton
In December 1823, Mary Anning discovered the first complete Plesiosaurus skeleton from the Lower Jurassic coast. It became one of the most celebrated fossil finds of the nineteenth century and helped establish the Charmouth–Lyme coast as one of the world’s great marine reptile localities.

1828 – Mary Anning discovered Britain’s first pterosaur
In December 1828, Mary Anning uncovered the remains of the first pterosaur found outside Germany, the fossil later known as Dimorphodon. This added flying reptiles to the already remarkable fossil record of the area.

1829 – coprolites were recognised as fossilised dung
Work by William Buckland on material from the Lyme Regis and Charmouth coast led to the recognition that certain curious stony objects were fossilised dung, or coprolites. This was another major scientific breakthrough linked to the fossil discoveries of this coast.

1858–1859 – Scelidosaurus discovered at Black Ven near Charmouth by James Harrison
Fossils found by James Harrison while working the Black Ven cliffs near Charmouth were sent to Richard Owen, who recognised their importance. This discovery made Charmouth one of the classic British dinosaur localities.

1861 – Scelidosaurus harrisonii formally described by Richard Owen
Owen formally described Scelidosaurus harrisonii in 1861. It became one of the most important early ornithischian dinosaurs ever discovered and remains central to discussions of armoured dinosaur evolution.

June 1955 – the museum acquired J. F. Jackson’s juvenile Scelidosaurus
The British Museum (Natural History) bought a fossil-bearing marlstone nodule found by J. F. Jackson on the beach beneath Black Ven. It contained a small, incomplete articulated skeleton. Its exact source bed is uncertain; Norman’s later study considered the Topstones Bed the likely source.

1968 – preparation of Jackson’s partial Scelidosaurus skeleton published
Arthur Rixon published an account of preparing the juvenile specimen now numbered NHMUK R6704. The work freed its delicate bones from the enclosing nodule and provided material for later anatomical comparisons. The discovery was on the Black Ven shore, within the wider Charmouth–Lyme area covered by this timeline.

1984–1985 – another important Scelidosaurus specimen recovered
Norman records the Bristol specimen, BRSMG Ce12785, as collected from the Topstones Bed by Simon Barnsley and Chris Moore in 1984–1985. It preserves a partial, disarticulated skull and skeleton together with patches of skin impressions and armour, supplementing the earlier discoveries.

December 2000 – David Sole found the most complete Charmouth Scelidosaurus specimen yet discovered
The first parts of this specimen were found in December 2000 by local collector David Sole. Over the following months and years, more pieces were recovered by David and fellow collectors Peter Langham, Jo Anderson, Andrew Sole, Christine Endecott, Rick Taylor and Bernie Abbott. The specimen proved to be over 85% complete, with exceptional preservation including skin and apparent stomach contents.

2000s–2010s – the David Sole Scelidosaurus became recognised as Britain’s most complete and best-preserved dinosaur
The Black Ven Scelidosaurus found by David Sole came to be regarded as Britain’s most complete and best-preserved dinosaur found to date. The specimen also showed that major dinosaur discoveries were still being made on the Charmouth coast in modern times.

2017–2018 – the future Turnersuchus specimen recovered
Paul Turner found the initial block and Lizzie Hingley recovered additional material and prepared the specimen. Its five main blocks emerged between May 2017 and July 2018 from eroded material about one kilometre west of Charmouth Heritage Coast Centre. The fossil comes from the lower Pliensbachian Belemnite Marl Member and includes parts of the skull, jaws, backbone and limbs.

2023 – Turnersuchus hingleyae formally described
The 2017 Charmouth specimen was formally described in 2023 as Turnersuchus hingleyae. The genus name honours Paul Turner, while the species name honours Lizzie Hingley. It is one of the oldest diagnostic thalattosuchians known and one of the most important recent discoveries from the Charmouth coast.

February 2024 – “Gonzo”, the mummified ichthyosaur, found by Chris Moore
In February 2024, local collector Chris Moore found an exceptionally preserved ichthyosaur nicknamed “Gonzo”. Charmouth Heritage Coast Centre reports associated shark teeth interpreted as a possible new hexanchiform species and an exceptionally early record of the group. The proposed shark identification remains provisional pending formal scientific description.

September 2024 – “Enzo”, a complete ichthyosaur, discovered by Chris Moore
Chris Moore discovered and excavated this complete ichthyosaur in September 2024, with special permission from the landowners to remove the specimen. The fossil is thought to represent an undescribed new species, with several unusual skeletal features including a pronounced overbite and an unusual hind paddle.

March–May 2025 – Enzo scanned and publicly presented as a likely new ichthyosaur species
In March 2025 the unusual skull was digitally scanned, and in May 2025 the specimen was publicly named “Enzo” in a Charmouth Heritage Coast Centre competition. Although not yet formally described in the scientific literature, it has been presented as a probable new species-level find from Charmouth.

Published bed numbers are retained, with source-specific corrections. The BGS member boundaries are used for the coloured hierarchy. The proposed Stonebarrow Pyritic subdivision is described within the broader BGS Black Ven Marl Member, so the same beds are not counted twice. Outcrop shifts, faults, cover and landslip mean this is a composite framework rather than a single continuously visible cliff log.

LIAS GROUP

Blue Lias Formation (Uppermost Part Only)

Western Basal Reference: Top Blue Lias

Grey Ledge

Grey Ledge (Lang Bed 49) is the highest persistent Blue Lias limestone in the western reference exposures. Its burrowed top marks the base of the Shales-with-Beef. Gallois places the exposed Blue Lias junction in the Church/East Cliff–Spittles sector west of the Black Ven fault zone; it is not assumed to be exposed beside the River Char on West Beach.

Charmouth Mudstone Formation (Lower Jurassic — Sinemurian to Pliensbachian)

Shales-with-Beef Member

The Shales-with-Beef Member forms the lowermost part of the Charmouth Mudstone Formation at Black Ven and is about 28–30 metres thick in the Lyme Regis–Charmouth area. It consists of thinly interbedded medium- to dark-grey mudstones, paler blocky calcareous mudstones and darker organic-rich laminated mudstones, with numerous bedding-parallel fibrous calcite seams or “beef”. The member contains several persistent limestones and concretion horizons that provide the real field framework for the Black Ven lower cliff.

Basal Erosion Surface And Lower Shales-With-Beef

At the western reference junction, basal laminated and interbedded mudstones overlie the burrowed top of Grey Ledge. Gallois’s SB 1 is the lower Fish Bed Shales interval, locally pyritic and containing crushed Arnioceras. This basal outcrop lies west of the immediate Charmouth shore; middle and upper member beds are exposed between Bar Ledges and the River Char.

Fish Bed Shales And Fish Bed — Western Reference Markers

The Fish Bed interval comprises lower fissile shales, then the Fish Bed itself as a strikingly laminated calcareous siltstone, followed by more dark shales and in places an “upper” Fish Bed siltstone. These beds are some of the most useful markers in the lower member and record episodic silt influx into otherwise muddy, organic-rich marine sedimentation. Fossils include fish debris, shell fragments and ammonites in adjacent shales.

Fish Bed (SB 2) — Western Reference

The lower marker is a tabular calcareous siltstone with conspicuous lamination in Gallois’s western reference framework. It is kept separate from the shale above and the younger upper Fish Bed.

Gallois gives 0.15–0.20 m for this marker in his coastal study framework. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Intervening Fish Bed Shales (SB 3)

Thinly bedded grey and organic-rich mudstones separate the two siltstone markers. This intervening muddy package is a distinct recorded unit, not part of one solid Fish Bed.

The published study-area range is 1.00–1.30 m. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Upper Fish Bed (SB 4) — Western Reference

The higher marker is a tabular calcareous siltstone with bioturbation, contrasting with the striking lamination of the lower Fish Bed. These lower-member markers are not promised at the River Char shore where the middle and upper member are exposed.

The study-area range is 0.10–0.15 m. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Saurian Shales (SB 5)

The interval below Table Ledge comprises thinly bedded grey and organic-rich mudstones. Its traditional name is retained as a stratigraphic label, without implying that vertebrate fossils are abundant in every exposure.

Gallois’s study-area range is 2.50–3.80 m. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Table Ledge

Table Ledge (Lang Bed 53; within Gallois’s SB 6) consists of pale muddy limestone lenses with rhynchonellid brachiopod clusters. It is a useful lower-member marker in the Spittles and more western reference sections; its position should not be inferred simply from a loose block on Charmouth West Beach.

Intervening Mudstones (SB 7) Above Table Ledge

Mainly thinly interbedded medium and dark grey mudstones with organic-rich brownish-grey laminated mudstones and numerous thin seams of beef. This interval is one of the thickest parts of the member and records persistent low-energy, oxygen-poor marine deposition punctuated by early diagenetic calcite growth.

The published range across the study area is 2.10–4.40 m, with individual thin beef seams generally below 10 mm. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Alcinoë Bed (Within SB 8)

Pale calcareous mudstone locally contains sparse concretions and crushed Pararnioceras alcinoë. This supplementary marker is less persistent than the main limestone framework.

Gallois gives the whole SB 8 package as 0.90–2.00 m across the study area; the fossiliferous concretion level is within it, not a limestone of that full thickness. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Devonshire Head Limestone

The Devonshire Head Limestone is a strong marker below the Spittles west of the Black Ven fault zone. Gallois explicitly found that this limestone, as such, is absent at Charmouth; Lang’s indurated marl (Bed 71a) may be its equivalent. The named western marker is retained here as correlation context, with that uncertainty rather than a claim of an identical local limestone.

Pale Calcareous Mudstone Above The Devonshire Head Level (SB 10)

This thin package contains small pale concretions; local phosphatic nodules indicate condensation. It is distinguished from the much thicker, organic-rich mudstones above.

The package is 0.50–0.70 m in the study framework, with local pale phosphatic material in its upper part. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Middle Shales-With-Beef

Dark grey mudstones, laminated brownish-grey bituminous mudstones and numerous thin seams of beef, with septarian concretions in places. This interval contains many of the classic fossil mudstones and contributes greatly to the instability of the lower Black Ven cliff.

Brookei Horizon Within Organic-Rich Mudstones (SB 11)

The thick fissile mudstone package includes a beef seam and sparse small septarian nodules at the traditional Brookei level in the eastern outcrop. Its basal lithological change may mark an erosional break.

Gallois gives 5.00–6.50 m for the whole SB 11 package; the upper nodules can be about 0.1 m across, whereas the distinct fissile interval at the base is about 0.4 m. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Black Arnioceras Bed (Base Of SB 12)

Discontinuous limestone lenses are locally crowded with jumbled ammonites. Gallois interpreted the photographed Spittles material as a storm-transported assemblage; the horizon is a supplementary marker, not a laterally continuous layer or an exposure guarantee.

The SB 12 package ranges from 2.30–2.50 m in the study framework; its discontinuous basal limestone lenses are up to about 0.12 m thick and 0.6 m long. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Spittles Limestone

The Spittles Limestone (SB 13) is tabular in its named western exposure but passes laterally into nodules with beef coatings or a multiple beef seam. Gallois found that a discrete Spittles limestone is absent at the Charmouth type section. That lateral change is important when matching West Beach mudstones to the western cliff log.

The named western marker is 0.20–0.35 m in Gallois’s framework, but a discrete limestone is absent at Charmouth; that dimension is therefore not asserted for West Beach. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Upper Beef-Bearing And Pyritic Mudstones (SB 14)

Thin grey and organic-rich mudstones contain several fine beef seams and pyritised layers below the terminal nodular interval. They form a separate intervening package above the Spittles marker level.

Gallois gives 3.30–4.30 m across the study area, with several beef seams and pyritised layers generally less than 10 mm thick. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Little Ledge (Lang Bed 74) — Charmouth Reference Marker

The GCR identifies Little Ledge as a sharp change into organic-rich paper shales higher in the Shales-with-Beef succession. It describes little benthic fauna in those shales, with chiefly ammonites and other swimming or drifting organisms, including the bivalve traditionally called Avicula and rare Pentacrinites. The historical Lang marker is retained without forcing an unsupported one-to-one correlation to a Gallois SB bed number.

Upper Shales-With-Beef And Birchi Nodules (SB 15)

Thinly interbedded grey mudstones and organic-rich mudstones with several thin beds of beef and one or two lines of septarian nodules. The Birchi Nodules are especially characteristic and may enclose Microderoceras birchi. These beds form the fossil-rich upper part of the member immediately beneath the Birchi Tabular boundary bed.

The terminal SB 15 package is 0.30–1.10 m in the study framework. Individual nodules may reach about 0.3 m across and 0.2 m thick; these nodule dimensions are not a bed thickness. These are source-specific coastal study ranges, not a newly measured continuous Charmouth column.

Total Thickness Of Shales-with-Beef Member At Black Ven: Approximately 28–30 Metres

Black Ven Marl Member

Birchi Tabular Bed (Lang Bed 76) — Base Of Black Ven Marl

The Birchi Tabular is a dense muddy limestone, commonly 0.15–0.30 m in the published coastal framework. The current BGS boundary is at its base, assigning the bed to Black Ven Marl rather than Shales-with-Beef. The underlying Birchi Nodules are a separate horizon in the upper Shales-with-Beef.

In the current BGS Lexicon the Black Ven Marl Member runs from the base of Birchi Tabular (Bed 76) to the base of Hummocky (Bed 103). The GCR also discusses a proposed narrower Black Ven/Stonebarrow Pyritic division near the Coinstone. Both conventions occur in the literature; the descriptive pyritic subdivision below does not create an extra thickness above the full BGS member.

Lower Black Ven Mudstones (Lang Beds 77–79)

Mudstones between Birchi Tabular and the Lower Cement Bed form the basal member interval. Callomon’s reassessment identifies a printing error in the 1926 account: the description of black conchoidal marl with indurated bands belongs to Bed 79, while the Lower Cement Bed is Bed 80. Keeping the numbers separate avoids turning the whole intervening marl into a cementstone.

Bed 80 — Lower Cement Bed / Lower Cementstone

The Lower Cement Bed is a laterally variable carbonate marker, about 0.3 m in the cited coastal log. Its limestone and dolomitic development contrasts with the adjacent mudstones. The classic printed description of conchoidal marl with indurated bands conflates Bed 79 with Bed 80 and should not be treated as the entire definition of this limestone marker.

Bed 81 — Inter-Cement Mudstones

Dark fissile mudstones and paper shales between the Lower Cement Bed and the Pavior. These beds continue the organic-rich, pyrite-prone sedimentation of the lower member and yield pyritised ammonites and other fossils where freshly exposed.

Under Pavior — Informal Comparative Name

West describes a concretionary carbonate below the Pavior in the Stonebarrow reference section and explicitly introduces “Under Pavior” as an informal convenience. It is not a formal member or a new established Lang bed number; its nearby example helps explain lateral cementation.

Bed 82 — Pavior / Upper Cement Bed

A second important cementstone horizon above Bed 80. It forms a useful datum bed and, together with the Lower Cement Bed, brackets one of the main lower fossil intervals in the Black Ven Marls.

Bed 83 — Obtusus Shales / Stonebarrow Flatstones

Bituminous paper shales with the classic flatstone nodules. This is one of the most famous horizons in the Black Ven succession, notable for uncrushed ammonites such as Asteroceras obtusum, insects in nodules and, regionally, vertebrate remains. It forms a strongly recessive but palaeontologically important interval.

Named Flatstone Horizons Within Bed 83

The GCR comparative log distinguishes Yellowstones, Woodstones, lower Flatstones, Goldstones and upper Flatstones, with a fissile interval above. These are individual nodule or shale horizons within the wider package, not separate formations. Their lateral persistence differs: Callomon notes that Woodstone is weak or absent and Lower Flatstones absent in much of the Stonebarrow outcrop, so the full Black Ven suite cannot be transferred unchanged eastwards.

Yellowstones — Lower Bed 83 Reference Horizon

The GCR Black Ven–Stonebarrow comparative figure identifies Yellowstones as the lowest of this named nodule-horizon series within Bed 83. No distinct mineral composition or thickness is inferred from the traditional name.

Lower Flatstones — Bed 83 Reference Horizon

Callomon’s explicit Black Ven lettered account identifies the Lower Flatstones as Bed 83d, below Woodstone (83f). Lower Flatstones are absent through much of the Stonebarrow section, so this is a retained Black Ven reference horizon rather than a universally exposed local layer.

Woodstones — Bed 83 Reference Horizon

Woodstone is Bed 83f in Callomon’s Black Ven lettered account, above the Lower Flatstones (83d) and below Upper Flatstones (83h). It is weak or absent through much of Stonebarrow and remains a lateral comparison here.

Goldstones — Bed 83 Reference Horizon

Goldstones are independently named in the GCR’s Bed 83 nodule suite. No new precise lettered crosswalk or local thickness is forced from its compressed graphic labels. It is kept distinct from the explicitly correlated Lower Flatstones, Woodstone and Upper Flatstones.

Upper Flatstones — Stonebarrow Flatstone Horizon

Callomon distinguishes Upper Flatstones numbered 83h in the Black Ven log from the correlated Stonebarrow Flatstones numbered 83e. Those western and eastern subdivisions are not interchangeable bed numbers. The GCR describes laminated lenticular limestone nodules with well-preserved fossils. They remain distinct from the lower reference horizons, which are not all developed east of the river.

Fissile Interval Above The Flatstones

The comparative log separately identifies a fissile muddy interval above the upper Flatstones. This preserves the top part of the Bed 83 package instead of treating every named horizon as one nodule bed.

Beds 84–86 — Middle Black Ven Marls

Dark mudstones and shales with nodular limestone development in parts, forming the less easily subdivided middle of the member. These beds continue the ammonite-bearing, organic-rich marl deposition and have yielded pyritised fossils, marine reptiles and dinosaur material in the broader Black Ven–Charmouth area.

Pentacrinite Bed (Lang Bed 84b)

The BGS memoir names the Pentacrinite Bed as Bed 84b. The fuller GCR description makes clear that it is an interval exceeding 2 m of organic-rich mudstone, with scattered groups of Pentacrinites fossilis, often associated with driftwood, rather than one continuous crinoid sheet. Its detailed development and correlatability vary between Black Ven and Stonebarrow.

Topstones (Lang Bed 85)

This named nodular marker, also associated with the “Mudstone” terminology of the older log, is separately identified in the GCR section between Bed 84 mudstones and the higher Bed 86 interval. The broader Black Ven record includes important vertebrate material at this level.

The GCR’s provenance discussion specifically assigns important Scelidosaurus specimens to this Topstones interval. The broader history of vertebrate discoveries must not make every Flatstone horizon an identical dinosaur-bearing bed.

Bed 87 — Limestone With Brachiopods

A thin limestone marker bed with brachiopods and shell debris. This is one of the best marker bands high in the Black Ven Marl Member and helps place the upper part of the member on the cliff face.

Bed 88 — Upper Black Ven Pyritic Marls And Stellare Nodules

Dark mudstones contain the septarian Stellare Nodules (Bed 88f), which sometimes preserve Asteroceras stellare. Pyritised ammonites below the Coinstone are relatively uncommon and may occur as coatings on crushed shells. The more abundant uncrushed pyritic ammonites are associated with the younger beds above the Coinstone, particularly Beds 90–102; these intervals should not be confused.

Bed 89 — Coinstone

The Coinstone (Bed 89) comprises reworked, bored and encrusted nodules. On Stonebarrow the hiatus coincides with this nodular surface; the GCR explicitly places the equivalent hiatus more than 1 m above the nodules on Black Ven, at a thin bored-belemnite horizon. The position must not be assumed identical at both cliffs. It is an internal break within the broader BGS Black Ven Marl Member.

Black Ven Marl Thickness Conventions: BGS Lexicon 43 m; BGS 2011 Coastal Account 48 m; GCR Alternative Lower Approximately 27 m And Upper Approximately 16.8 m

Historical Pyrite Working — Member-Level Provenance

The BGS Sidmouth account records a pyrite-rich “Metal Bed” in the Black Ven Marl succession worked for sulphuric-acid manufacture. This retains the useful industrial history at member level; it is not assigned without evidence to the Lymense Bed or another exact Lang number.

In the GCR’s alternative subdivision, approximately 27 m extends from Birchi Tabular (76) to the Coinstone-area hiatus, with about 16.8 m of upper pyritic beds above. These are that source’s measured subdivisions, not extra units to add to the separate 43 m Lexicon or 48 m memoir estimates.

Upper Pyritic Interval — Proposed Stonebarrow Pyritic Member In The GCR Scheme

The upper pyritic beds above the Coinstone-area hiatus are retained here as a useful descriptive interval within the current BGS member. The GCR discusses a proposed Stonebarrow Pyritic Member for this approximately 16.8 m succession. It is rich in pyritised ammonites and has fewer large nodules than the underlying part, but contains distinct marker horizons that must retain their correct bed numbers.

Beds 90–94 — Lower Pyritic Marls

The lower pyritic mudstones above the hiatus include the Lymense horizon. The GCR restricts Oxynoticeras lymense to the basal Densinodulum interval, Lang Beds 90–92, rather than placing it in Beds 95–98. The wider pyritic succession contains Crucilobiceras, Eoderoceras and Echioceras; these are not a claim that every genus occurs in each bed.

Lymense Bed — Within The Lower Beds 90–92 Interval

The characteristic smooth pyritised ammonites belong to the lower part of the pyritic succession. The exact source-defined horizon is kept below the younger middle beds rather than grouped with them.

Beds 95–98 — Middle Pyritic Marls

These middle mudstones contain pyrite and locally thin beef seams, continuing above the lower Lymense interval. They lead upwards towards the Watch Ammonite Stone. The name Lymense is not assigned to this younger group.

Bed 99 — Watch Ammonite Stone

The GCR identifies the Watch Ammonite Stone as Lang Bed 99, a lenticular limestone up to about 0.3 m in the coastal reference. It contains abundant Echioceras of the aeneum group and a richer benthic fauna than the surrounding mudstones. It is below Beds 100–102, not itself Bed 102.

Beds 100–102 — Upper Pyritic Marls

These mudstones lie above the Watch Ammonite Stone and below the Hummocky boundary limestone. The GCR notes a faunal and lithological change about 1.6 m below Hummocky, from laminated towards more homogeneous mudstone; it is a separate upper-interval feature.

Upper Pyritic Interval: Approximately 16–17 m In The GCR Proposed Subdivision; Included Within The Broader BGS Black Ven Marl Member

Belemnite Marl Member

The bed framework below combines directly observed Stonebarrow beds with explicitly identified reference measurements farther east. Hesselbo and Jenkyns (1995) measured Beds 103–109 below Stonebarrow, reconstructed Bed 110 from cliff photographs there, measured Beds 111–115 east of Westhay Water, and measured Beds 116–121 between The Corner and Seatown. The upper dimensions are not transferred to every Stonebarrow or Black Ven exposure. Every main bed is retained, together with subdivisions independently recorded by Bolton (1982); unsupported historical inch values are not presented as modern measurements.

Bed 103 — Hummocky Limestone

The irregular nodular limestone marks the lithostratigraphic base of the member. Its bioclastic fabric includes burrows, reworked limestone fragments and worn skeletal material. Hesselbo and Jenkyns discuss mixing and erosion through this basal interval rather than an undisturbed, instant boundary. BGS gives approximately 0.10–0.15 m for the thin basal and terminal limestones in its coastal summary; the GCR describes local merging of Beds 103–105 into a thicker complex bed below Black Ven.

Bed 104 — Clays Above Hummocky

The thin muddy interval above the basal limestone includes small nodules and reworked clasts. The GCR describes approximately 0.10 m in its coastal account. Published interpretations place the earliest Pliensbachian either at Hummocky or above parts of this mixed interval; the secure lithological order is kept separate from that disputed time boundary.

Bed 105 — Apoderoceras Or Armatus Limestone

A pale bioclastic limestone with distinctive burrowing and large ammonites forms the next resistant marker. The GCR coastal account gives approximately 0.30–0.40 m. It was included in the directly measured Stonebarrow part of the 1995 composite; this range is not inferred from its drawing scale.

Bed 106 — Lower Pale Marl Rhythms

The lower pale interval continues above the Armatus Limestone with alternations of calcareous mud and harder carbonate-rich layers. Bolton’s log retains subdivisions 106a, 106b and 106c. Their identities are retained without assigning unverified individual inch measurements.

Subdivisions 106a–c

These three retained log subdivisions belong within Bed 106. Their separate identification is supported by Bolton’s figure; the old thickness assigned to each is held in the historical comparison rather than inferred anew.

Bed 107 — Lower Pale Indurated Band

A separately numbered thin, harder pale interval lies between Beds 106 and 108 in the published lithological framework. The lower Taylori assemblage includes Apoderoceras and Phricodoceras in the BGS account, but an exact bed-specific faunal name is not imposed here without its original evidence.

Bed 108 — Marl Rhythms With Two Bituminous Horizons

Bolton records two organic-rich shale horizons in this interval: one at the base and a second approximately 0.3 m below Bed 109. The latter yielded documented vertebrate material in that field study. These are useful lithological subdivisions within the marl package, not a reason to promise fossils in every exposure. The particular old faunal bed label is not required for identifying the supported rock succession.

Lower Bituminous Shale In Bed 108

The basal organic-rich horizon is distinguished from the upper shale in Bolton’s direct field description.

Upper Bituminous Shale In Bed 108

Bolton describes this second horizon about 0.3 m below Bed 109; it is not simply another name for all of Bed 108.

Bed 109 — Upper Indurated Band Of The Lower Pale Interval

A harder pale band closes the lower marl package below the thick Bed 110 succession. It remains a separately numbered horizon in the 1995 measured framework; no exact local thickness is assigned from the graphical scale.

Bed 110 — Lower Darker Marl Succession

The thick lower dark interval contains subtle carbonate-rich and carbonate-poor alternations, with organic-rich shale towards its base. The 1995 reconstruction of this bed was made from photographs of Stonebarrow cliff. Bolton distinguishes the principal historical subdivisions 110a and 110b and, separately, five study units I–V based on belemnite assemblages. The latter are research subdivisions, not new formal members.

Bed 110a

The lower historical division contains faint marl rhythms and basal organic-rich levels. Bolton’s Dorset account describes about 8.5 m, while the 1995 presentation reconstructs the local cycle pattern photographically. The source-specific estimate is not a precision measurement derived from the figure.

Bed 110b

The upper historical division participates with Bed 111 in the more clearly expressed rhythmic succession. Its separate identity is retained, but no independent modern individual thickness is asserted.

Bed 111 — Lower Pale Band

This conspicuous light-coloured package includes three harder pale components separated by softer marls. Bolton retains the five subdivisions 111a, 111b, 111c, 111d and 111e. His discussion associates this interval and Bed 113 with brachiopods including Cincta. The 1995 section for these beds was measured east of Westhay Water, not at the same face used for Bed 110.

Retained Subdivisions 111a, 111b, 111c, 111d, 111e

These lettered subbeds are independently recorded in Bolton’s lithological framework. The description preserves the full subdivision sequence while withholding unverified historical inch-level dimensions; the contrasting marls and harder pale intervals are described at the supported package level above.

Bed 112 — Lower Darker Band

Darker, less carbonate-rich alternations follow the lower pale package; Bolton notes an organic-rich shale towards the top. The six recorded subdivisions, 112a through 112f, are preserved in the framework, without presenting the old individual inch values as newly verified dimensions.

Retained Subdivisions 112a, 112b, 112c, 112d, 112e, 112f

These lettered subbeds are independently recorded in Bolton’s lithological framework. The description preserves the full subdivision sequence while withholding unverified historical inch-level dimensions; the contrasting marls and harder pale intervals are described at the supported package level above.

Bed 113 — Middle Pale Band

The next pale rhythmic package is separately identified in the GCR and 1995 figures. Bolton retains subdivisions 113a, 113b, 113c, 113d and 113e and records ammonites and brachiopods in this part of the succession. Its repeated pale and darker components remain important field detail even where no individual numerical thickness is assigned.

Retained Subdivisions 113a, 113b, 113c, 113d, 113e

These lettered subbeds are independently recorded in Bolton’s lithological framework. The description preserves the full subdivision sequence while withholding unverified historical inch-level dimensions; the contrasting marls and harder pale intervals are described at the supported package level above.

Bed 114 — Middle Dark Band

This darker marl interval separates the middle and upper pale packages. Bolton describes the fauna of Beds 113–114 as chiefly ammonites and brachiopods, with belemnites less prolific than in much of the surrounding member. It is not presented as uniformly rich in all fossil groups.

Bed 115 — Upper Pale Band

Numerous finer pale–dark rhythms make this a distinctive package. Bolton explicitly attributes Lang’s 8 ft (about 2.4 m) to Westhay Water and records thinning to about 1.5 m at Ridgewater. These two named-locality values are retained as variation, not merged into a universal Stonebarrow measurement. The historical narrow taxon “zone” is not used as the modern zonal definition.

Bed 116 — Upper Dark Band

This dark calcareous clay lies above the upper pale package. Bolton reports a marked lack of belemnites in this bed in his study, despite otherwise broadly similar marine fauna. In the 1995 composite, this and higher beds were measured in the low cliffs towards Seatown.

Bed 117 — Upper Paler Marls

The succeeding lighter marl interval restores a more visibly calcareous component. Bolton records belemnites here. Lang’s earlier 1913 account gives 2 ft, but that historical figure is not silently treated as a new 1995 local measurement.

Bed 118 — Upper Darker Marls

The upper dark succession retains four historical subdivisions. Bed 118a is the lower marl interval with relatively abundant belemnites in Bolton’s study. Bed 118b is the thin historical one-inch horizon directly corroborated by Bolton, but he found it lithologically indistinguishable from 118c; its former Coeloceras pettos “zone” is obsolete. Bed 118c and Bed 118d continue the muddy rhythmic succession towards the Belemnite Shales. Modern measured values from different studies are not silently substituted for the old whole-bed dimensions.

Bed 118a

Lower marl subdivision; its fossil abundance is described in the main entry.

Bed 118b

Thin historical horizon, one inch in the account explicitly cited by Bolton; not a separate modern ammonite zone.

Bed 118c

Marl rhythms above the thin historical 118b horizon; the two are not readily separated by lithology in Bolton’s account.

Bed 118d

Upper marl subdivision below the Belemnite Shales, retained separately in the primary log. Lang’s 1928 plate explanation records the holotype of the belemnite he named Angeloteuthis uriel, B.M. C28985, from Bed 118d at Black Ven. This supplies an exact historical specimen-to-bed link; the name is quoted in its original usage and does not identify every belemnite from this interval.

Bed 119 — Belemnite Shales And Inferior Belemnite Horizon

The sediment changes from the stronger calcilutite–clay rhythms to alternating more and less calcareous shale. Hesselbo and Jenkyns separately identify an Inferior Belemnite Bed approximately 60 cm below the main Belemnite Bed in their upper Corner–Seatown measured section. That relative position is reported directly, without inventing an exact lettered subbed or transferring its distance to every cliff.

Bed 120 — Upper Pyritic Interval And Belemnite Bed

The historical subdivisions remain distinct. Beds 120a–b comprise dark organic-rich pyritic shale with scattered nodules and a concentration at the top, as independently described by Bolton. Bed 120c is the main condensed belemnite-rich horizon identified by BGS. Beds 120d and 120e have broadly similar muddy lithology but fewer pyrite nodules in Bolton’s account. The highest thin subdivision must not be conflated with the main belemnite concentration.

Beds 120a–b — Pyritic Marls

The lower pyritic package and its upper nodule concentration are retained together as in Bolton’s description; their unverified old one-foot aggregate is not treated as a modern measured value.

Bed 120c — Main Belemnite Bed

Hesselbo and Jenkyns describe the named Belemnite Bed as about 7–8 cm thick and 34 cm below Belemnite Stone in their upper measured section. It is a diffuse dark pyritic, organic-rich mudstone rich in belemnites and bivalves. These are Corner–Seatown source values, not exact dimensions of all Stonebarrow or Black Ven occurrences.

Bed 120d

This intervening upper muddy subdivision is retained separately from the main Belemnite Bed and the highest crumbly horizon. Bolton reports lithology broadly similar to the lower pyritic package, with fewer nodules; no exact thickness is supplied here.

Bed 120e — Uppermost Retained Subdivision

Bolton retains the highest subdivision within the upper muddy interval. Lang’s 1928 detailed sequence describes Bed 120e as the uppermost half-inch of the Crumbly Bed, composed of greyish-black friable marl. That is a historical coastal reference-section value, not a newly measured thickness at this cliff. Lang used Crumbly Bed for subdivisions 120c–e, whereas the GCR Blockley comparison specifically correlates with Dorset Bed 120e. The broader historical name must therefore not be confused with either the single uppermost subdivision or the main belemnite concentration at 120c.

Bed 121 — Belemnite Stone

This terminal pale concretionary limestone is highly condensed and rich in belemnites and other skeletal material. Hesselbo and Jenkyns explicitly record 4–5 cm in their upper Corner–Seatown section. The BGS memoir uses a broader approximately 0.10–0.15 m description for the member’s boundary limestones, and other published local accounts differ. These are attributed source/locality values, not a fabricated single agreed thickness. The stone forms the top of the member below Green Ammonite mudstones.

Belemnite Marl Member Thickness And Exposure Scope

BGS 2011 describes approximately 25 m in the Stonebarrow cliffs. Other sources give approximately 23 m for the coastal framework and 22–25 m at Black Ven. These source-scoped totals are not added together or imposed on a single currently visible face. The thin upper-marker measurements above derive from the specifically stated reference exposures.

Green Ammonite Member — Incomplete Eastern Remnant

Lower Green Ammonite Mudstones Above Belemnite Stone

BGS records up to 6 m of deeply weathered, partly slipped grey mudstone with ironstone nodules beneath the Cretaceous unconformity at eastern Black Ven. The GCR gives about 5 m. These are remnant estimates, not a complete measured Green Ammonite succession; higher Lower Limestone–Red Band–Upper Limestone logs from Stonebarrow and Golden Cap are not imported here.

SELBORNE GROUP

Gault Formation (Lower Cretaceous)

Basal Pebble Bed On Burrowed Jurassic Mudstone

The BGS Sidmouth explanation reproduces Reid’s historical eastern Black Ven section, with a basal pebble bed resting on a burrowed Lias surface. This is a locally recorded transgressive contact, not an invented continuous bed across every landslip.

Gault Clay And Sandy Clay — Historical Eastern Black Ven Section

Reid’s recorded local succession contained 5.3 m of fossiliferous clay and sandy clay at eastern Black Ven [SY 358 932], as quoted by BGS. Its historical measurement is retained with that provenance; it is not a present-day cliff-height promise or a value transferred to Stonebarrow.

Basal Cretaceous Unconformity

The Jurassic succession at Black Ven is cut by a marked erosional unconformity and overlain by dark grey Gault clay. At the eastern end of Black Ven, the Belemnite Stone and a limited thickness of weathered grey mudstone remain beneath this unconformity. The Green Ammonite Member is therefore not preserved here as a full cliff section.

Upper Greensand Formation (Lower Cretaceous)

Foxmould And Chert Beds

The cliff top above Black Ven is capped by Upper Greensand sands and cherts, which drive much of the modern landslip behaviour by feeding debris onto the Gault and Jurassic benches below. These Cretaceous units are not part of the Lower Jurassic fossil section but are an essential part of the Black Ven cliff profile.

Foxmould Member

Sand And Sandstone Dogger Levels

The lower Upper Greensand includes sandy beds and resistant concretions in the Black Ven cap. Weathering removes carbonate cement and produces softer yellow-brown sand. Historical “Cowstone” terminology describes harder dogger horizons; it is not a new formation. Whole-member thickness estimates differ between published accounts and are not added to a local measured cliff total.

Whitecliff Chert Member

Chert-Bearing Upper Beds

Higher Upper Greensand beds contain chert horizons. Decalcification leaves angular chert within weakened sandy debris, contributing material to the slope. The named member is recorded in the Black Ven setting, but transported chert on West Beach alone cannot identify an in-situ bed beneath the observer.

Superficial Cover Outside The Whitecliff Chert Member — Residual Clay-With-Flints

Gallois describes the Clay-with-flints plateau associated with the upper Black Ven–Spittles setting. Residual and reworked cover is kept separate from the in-situ Cretaceous member succession; landslip can mix it with sand and chert on the slope. No layer thickness is assigned from transported debris.

Depositional Environment

The Black Ven succession records a long transition from carbonate-mud shelf deposition in the top Blue Lias, into organic-rich oxygen-poor mudstones with frequent early diagenetic calcite seams in the Shales-with-Beef Member, then into darker ammonite-rich marls and cementstones of the Black Ven Marl Member, including the pyrite-rich upper Sinemurian interval termed the proposed Stonebarrow Pyritic Member in the GCR scheme, followed by the paler belemnite-rich marls of the lower Pliensbachian Belemnite Marl Member. The whole Jurassic section is finally cut by a major Early Cretaceous erosional surface.

Composite Coastal Framework: No Summed Total Assigned Across Different Exposure And Boundary Conventions

References

Gallois, R.W. (2008). The lithostratigraphy of the Shales-with-Beef Member of the Charmouth Mudstone Formation, Lower Jurassic.
Lang, W.D. & Spath, L.F. (1926). The Black Marl of Black Ven and Stonebarrow, in the Lias of the Dorset coast.
Lang, W. D., Spath, L. F., Cox, L. R. and Muir-Wood, H. M. (1928), The Belemnite Marls of Charmouth, a Series in the Lias of the Dorset Coast, stratigraphic and belemnite section, pp. 179–222.
British Geological Survey Lexicon: Shales-with-Beef Member, Black Ven Marl Member and Belemnite Marl Member.
British Lower Jurassic Stratigraphy (JNCC GCR volume) and west Dorset coastal field guides.

Gallois (2008), revised Shales-with-Beef framework and exact exposure map. BGS Black Ven Marl definition. BGS Sidmouth district: eastern Black Ven remnant and cover. GCR30, local detailed succession and Figure 2.8.

Hesselbo and Jenkyns (1995), measured sections and exact exposure provenance, pp.115–119. Bolton (1982), independently described beds and retained subdivisions, pp.18–22 and Figure 2. BGS (2011), formal member framework and Figures 11–12.

GCR Blockley comparison: explicit historical Dorset Bed 120e correlation.