Haven Cliff, Seaton Fossil Hunting

1903 – regional context: Rowe documented the Devon Chalk succession
A. W. Rowe described fossil zones and marker beds along the Devon coast, including the Beer–Seaton area. This regional work underpins later correlations of the local Chalk. It should not be read as evidence that every echinoid or zonal record from the western Seaton cliffs was collected at Haven Cliff, east of the Axe.

1965 – the Cenomanian Limestone east of Seaton was described
W. E. Smith published a study of the Cenomanian Limestone east of Seaton, examining lateral variation in the cliffs, landslips and beach blocks between Haven Cliff and Pinhay Bay. The work provided a basis for comparing these eastern exposures with the better-known sections around Beer.

1984 – the Haven Cliff Neocardioceras Hardground was formally recognised
Jarvis and Woodroof formally recognised the Haven Cliff Neocardioceras Hardground at the top of the Pinnacles Member. This hardground contains moulds of terminal Cenomanian ammonites including Neocardioceras juddii and Sciponoceras, together with echinoid spines such as Hirudocidaris hirudo.

1984 – the Haven Cliff Hardground was shown to mark the base of the Seaton Chalk
The same work demonstrated that the surface of the Haven Cliff Neocardioceras Hardground marks the base of the Seaton Chalk Formation in their historical lithostratigraphical scheme. This made Haven Cliff a key reference point for the boundary between the Beer Head Limestone and the overlying chalk succession.

Late 20th century – Haven Cliff became recognised as a key Cenomanian–Turonian boundary section in south-east Devon
The hardground and overlying chalk preserve evidence from around the Cenomanian–Turonian transition, but the condensed, reworked assemblage should not be treated as an exact global time-boundary surface. This made Haven Cliff important not just for collectible fossils such as ammonites, bivalves and echinoids, but also as a marker section for one of the most important boundaries in the Upper Cretaceous.

Section Architecture

Haven Cliff lies east of the Axe mouth; White Cliff is the separate headland west of Seaton towards Beer. The upper Triassic reference section runs below Haven towards Sparrowbush Ledge, with Blue Anchor exposures continuing towards Culverhole. Cretaceous material occurs in the higher cliffs and landslips. White Cliff provides important Upper Greensand and Chalk reference logs, but its thicknesses and individual exposures are not measurements made at Haven. Faulting, landslips, erosional omission and hardground convergence all complicate correlation. HC labels are editorial packages, not formal published bed numbers.

MERCIA MUDSTONE GROUP

Branscombe Mudstone Formation (Late Triassic: Norian–?Rhaetian)

Seaton Mudstone Member (Gallois local subdivision)

Bed HC1 — Upper Seaton Mudstone Member (Highest c. 25 m Exposed Beneath Haven Cliff)

Gallois (2001) recorded the highest 25 m of the Seaton Mudstone Member below Haven Cliff between the River Axe outfall and Sparrowbush Ledge. It consists of relatively uniform red-brown to orange-brown mudstones and silty mudstones with only a few distinctive marker horizons, so the interval is better treated as a broad upper-member unit rather than as a series of formal beds. Gypsum veins and their weathering residues are described from the wider Seaton Member, especially its lower part. They should not be taken as a demonstrated marker in every bed of the upper 25 m exposed at Haven. Interpretation: deposition on an arid continental mudflat to low-relief sabkha plain; body fossils are rare to absent, and the unit is mainly important here as the immediate substrate below the Haven Cliff variegated beds.

Haven Cliff Mudstone Member (Gallois local subdivision)

Bed HC2 — Haven Cliff Mudstone Member (19 m; Base Marked By A 0.9 m Green Siltstone)

This is the classic variegated upper Branscombe Mudstone developed beneath Haven Cliff. The base is defined at the base of a prominent green siltstone about 0.9 m thick, above which the member comprises interbedded red and green mudstones in beds mostly 0.2–0.4 m thick. The alternation of oxidised red beds and reduced green beds gives the cliff a strongly colour-banded appearance and makes the unit one of the easiest Triassic markers to recognise in the Seaton–Axmouth coast. Lithology: mainly mudstone with subordinate siltstone; blocky weathering; colour-banding far more conspicuous than in the Seaton Mudstone below. Interpretation: fluctuating oxidation and reduction on a saline mudflat or playa-margin surface, still dominantly continental and evaporitic in character but more internally differentiated than the Seaton Mudstone.

Basal green siltstone (0.9 m in Gallois’s log)
This prominent green bed defines the local member base above the predominantly red-brown Seaton mudstones.

Overlying “Variegated Marls”
Alternating red and green mudstone beds, mostly 0.2–0.4 m thick, make up the remainder of the 19 m local member. Gallois estimated about 60% red beds. The source does not give each repeated bed a distinct published name or number.

Blue Anchor Formation (Upper Triassic: latest Norian–Rhaetian)

Bed HC3 — Blue Anchor Formation (c. 29 m In The Sparrowbush Ledge–Culverhole Point Reference Section)

Included here because it completes the upper Triassic succession developed east of the main Haven Cliff mudstone section, the Blue Anchor Formation is exposed on the south Devon coast between Sparrowbush Ledge and Culverhole Point. It is a pale green-grey to grey dolomitic mudstone and silty mudstone succession with thin laminae, lenses and a few harder dolomitic or porcellanous beds, the base being taken at the lowest prominent dolomitic limestone above the red-and-green mudstones of the Haven Cliff Member. Darker grey mudstones occur locally, and the overall colour shift from variegated red-green mudstone below to cooler green-grey dolomitic beds above is very distinctive. Interpretation: supratidal to intertidal dolomitic mudflat and sabkha deposition with increasing marine influence toward the top, forming part of the late Norian(?)–Rhaetian transition above the red beds. It is not entirely pre-Rhaetian.

Basal dolomitic limestone
Gallois places the local Blue Anchor base at the first prominent dolomitic limestone above the red-and-green mudstone package. Thin reddish beds persist in the lower formation.

Blue Anchor thickness and internal variation
The adjoining Haven–Culverhole section was measured as 23 m by Richardson and 29 m by Gallois; these are separate published results. Cream dolomitic siltstone is more conspicuous low in the formation, whereas darker grey mudstone and silty mudstone occur higher. Neither record is a thickness for the entire Haven guide locality.

Upper Triassic Section Note

At Haven Cliff the exposed upper Triassic interval is substantial, but it is not a single uninterrupted measured log. The highest c. 25 m of the Seaton Mudstone Member, the full 19 m Haven Cliff Mudstone Member, and the overlying Blue Anchor Formation are best treated as adjoining reference sections linked by coastal walk-out and regional mapping, not as one perfectly continuous cliff face.

Cretaceous rocks at Haven, with separate White Cliff reference detail

The Upper Greensand overlies Triassic mudstone at Haven and contributes landslip blocks. Its three-member framework is useful locally, but the detailed type-section descriptions below derive mainly from White Cliff, west of Seaton, and from the wider east Devon coast. They are retained as comparisons; no complete four-bed Bindon log or western type-section thickness is asserted for Haven.

SELBORNE GROUP

Upper Greensand Formation (Upper Albian)

Unconformity Note

At White Cliff, the Cretaceous succession rests unconformably on eroded Mercia Mudstone, so the normal Jurassic cover and the Gault are absent locally. A comparable major erosional break separates the Upper Greensand from older mudstone at Haven, but White Cliff and Haven are separate exposures on opposite sides of Seaton. Towards Culverhole the Cretaceous overstep reaches the younger Penarth rocks.

Foxmould Member

Bed HC4 — Foxmould Member (White Cliff Reference; 25–30 m Regional East Devon Thickness)

The Foxmould Member forms the lower and thickest part of the Upper Greensand at White Cliff, where the full thickness and both bounding junctions have been recorded at different times. Gallois emphasised that debris often covered the lower beds, so a complete contemporary exposure was not guaranteed. It consists of fine- to medium-grained weakly cemented glauconitic sandstones with variable silica and calcium carbonate, fresh colours ranging from faint green-grey to bright green and weathered faces breaking down to soft grey, yellow and brown sands. The basal junction on Mercia Mudstone is marked by a pebble bed intensely let down by burrowing into the red mudstones. Shell debris and broken shells are common at many levels, especially oysters, pectinids and serpulids, and weak hardgrounds occur in the upper part. Typical Fossils: robust bivalves, gastropods, echinoderm debris, brachiopods and serpulids; ammonites are uncommon and mostly ex situ on the Devon coast. Ammonite Age: regional ammonite evidence places the member in the Mortoniceras inflatum Zone, with Hysteroceras varicosum and related forms recorded from comparable horizons and some ex situ Devon coast material suggesting the Callihoplites auritus Subzone higher in the unit. Depositional Environment: relatively deep subtidal marine sand deposition above storm wave base.

Whitecliff Chert Member

Bed HC5 — Whitecliff Chert Member (12–18 m In Gallois’s East Devon Regional Account)

The base of the Whitecliff Chert Member is taken at a dark green pebbly glauconite-rich sand infilling an irregular mineralised erosion surface above the Foxmould, marking a major change from weakly cemented quiet-water sands to strongly cemented calcareous sandstones and shell-rich calcarenites. Cherts are abundant above the basal hardground interval and are mostly translucent dark brown with pale shell-derived inclusions; individual chert beds are commonly 0.15–0.3 m thick and may reach 0.5 m. Hardgrounds, scour hollows and shell-debris-rich or clast-rich infills recur through the member, and some cherts preserve cross-bedding and bioturbation. Typical Fossils: thick-shelled oysters dominate, with other bivalves, serpulids, brachiopods and echinoderm debris; in situ ammonites are not known from this member on the Devon coast. Ammonite Age: loose material suggests correlation with the Callihoplites auritus Subzone. Depositional Environment: shallow, strongly current-agitated fully marine conditions, at times possibly intertidal or very near shoreface shoal conditions.

Culverhole hardground pair at the member base
A glauconite-rich pebbly bed above the lower mineralised erosion surface is commonly capped by a second hardground. These are named from Culverhole, and their presence in the regional/type-section description must not be confused with a measured Haven bed pair.

Chert-rich beds and internal erosion surfaces
Cherts become abundant above the upper basal hardground, with partly silicified “quasi-cherts” in lower layers. Repeated shell-rich and clast-rich scour fills occur, but Gallois did not establish each internal surface as a laterally persistent named marker.

Bindon Sandstone Member

HC6–HC9 retain Gallois’s regional four-bed scheme. These beds vary laterally and are described here for comparison with Haven debris and neighbouring sections, not as four individually verified in-situ Haven measurements.

Bed HC6 — Bindon Sandstone Bed 1 — Basal Coarse Band

The Bindon Sandstone begins at the Whitecliff Hardground and the overlying pebbly glauconite-rich Coarse Band. This bed infills relief on the hardground and provides one of the most reliable markers in the upper Upper Greensand succession. Pebbles and glauconitic granules are concentrated in a sandy, locally shell-rich matrix, and the erosive base records a renewed sedimentary break before deposition of the uppermost Greensand sands and calcarenites. Interpretation: transgressive or erosive lag resting on a prominent hardground surface in a high-energy shallow-marine setting.

Bed HC7 — Bindon Sandstone Bed 2 — Chert-Bearing Glauconitic Calcarenites

Above the Coarse Band lies a glauconitic calcareous sandstone to calcarenite with up to six chert horizons, some individual cherts reaching about 0.6 m thick. The rock is typically shell-detrital and calcareous, and where fresh may be tough and massive. This is the most conspicuously chert-bearing part of the Bindon Sandstone in expanded sections. Typical Fossils: shell debris, bivalves, gastropods and echinoderm debris; age-diagnostic ammonites are uncommon in situ. Interpretation: shallow marine calcarenite shoals or bars subjected to repeated cementation, erosion and silicification.

Bed HC8 — Bindon Sandstone Bed 3 — Chert-Free Cross-Bedded Sandstones

Bed 3 has a matrix similar to Bed 2 but is distinguished by the absence of chert and by wavy bedding and low-angle trough cross-bedding picked out by glauconite-rich stringers. The junction with Bed 2 is locally sharp and channelled, and chert-free channel fills may cut out much or all of Bed 2. Because of this channelisation the bed can change thickness rapidly across short distances. Interpretation: mobile sand bodies and channels in a strongly current-swept shallow shelf or shoreface setting.

Bed HC9 — Bindon Sandstone Bed 4 — Upper Cross-Bedded And Shell-Rich Sandstones

The highest Bindon Sandstone is sedimentologically distinct, showing festoon trough cross-bedding and, in its upper part, local contortion attributed to slumping and/or dewatering. The topmost beds contain concretionary shell accumulations rich in bivalves and gastropods, and one such shell concentration at Shapwick yielded the only in-situ member assemblage reported in Gallois’s 2004 review. This is a Shapwick Quarry record, not a Haven Cliff collection. Typical Fossils: abundant bivalves and gastropods in shell pockets, with rarer ammonites. Ammonites: species of Callihoplites, Discohoplites, Hyphoplites, Idiohamites, Stoliczkaia and Stomohamites indicate the Arrhaphoceras (Praeschloenbachia) briacensis Subzone of the Stoliczkaia dispar Zone. Interpretation: very shallow high-energy marine sand bodies with local soft-sediment instability immediately below the basal chalk unconformity.

Upper Greensand Thickness Note: Published Member Ranges Refer To Regional Or White Cliff Sections; No Complete Measured Haven Total Is Assigned

CHALK GROUP

The modern national scheme separates Grey Chalk from White Chalk. Historical Devon member names remain useful for reading the older logs and are retained below as labelled local subdivisions. Their regional maximum thicknesses are not Haven measurements; the original account’s combined “White Cliff–Haven” section was geographically misleading.

GREY CHALK SUBGROUP

Structural And Stratigraphic Note

The Cenomanian and lower Turonian succession across the separate Haven Cliff, White Cliff and Hooken sections is highly variable over short distances. Synsedimentary fault control around the Hooken–Wilmington trough caused local thickening of arenaceous Cenomanian beds and lower Turonian chalks, while adjacent structural highs show sharp attenuation, onlap and convergence of hardgrounds. Where this interval is attenuated, hardgrounds converge and may form a thin composite bed; this is a regional lateral trend rather than a measured thickness assigned here to Haven, so the section must be treated as laterally variable rather than diagrammed as a falsely uniform cliff log.

Beer Head Limestone Formation (Cenomanian)

Pounds Pool Sandy Limestone Member (historical Devon scheme)

Bed HC10 — Pounds Pool Sandy Limestone Member (3.5 m At Pounds Pool Stratotype)

This basal member rests on the Small Cove Hardground at the top of the Upper Greensand and consists of very coarse calcareous sandstones with common glauconitised intraclasts passing up into pale brown, strongly indurated sandy bioclastic limestone. It is the basal chalk-equivalent unit of the Devon coast and may be locally attenuated or entirely cut out on palaeotopographic highs. Typical Fossils: sparse to moderate shell debris, with the ramose chaetetid-like form Acanthochaetetes ramulosus classically used as a recognition fossil where the bed is well developed. Interpretation: shallow marine, winnowed, sand-rich carbonate deposition on an erosive surface at the base of the Cenomanian limestone succession.

Hooken Nodular Limestone Member (historical Devon scheme)

Bed HC11 — Hooken Nodular Limestone Member (Up To 5 m At Hooken; Not A Haven Thickness)

The Hooken Nodular Limestone is a medium- to light-grey bioclastic and rubbly nodular limestone above the Weston Hardground and below the Kings Hole Hardground. It is one of the most fossiliferous members of the Beer Head Limestone where expanded, but it is notably variable and can thin to less than 0.25 m or disappear altogether on local highs. Typical Fossils: reworked and indigenous ammonites, echinoids, brachiopods and bivalves are all characteristic, and the member commonly has a shell-rich, condensed aspect. Interpretation: condensed shallow-shelf limestone deposition with repeated sediment starvation, winnowing and hardground development.

Little Beach Bioclastic Limestone Member (historical Devon scheme)

Bed HC12 — Little Beach Bioclastic Limestone Member (Up To 1.75 m At The Beer Stone Adit)

This member is an indurated bioclastic limestone capped by the Humble Point Hardground and locally underlain by a phosphatised cavernous hardground shortly above its base. Around Beer Head and westward it may be strongly attenuated or absent, but where present it forms a distinct condensed bioclastic interval above the Hooken Nodular Limestone. Typical Fossils: the echinoid Holaster subglobosus is especially characteristic, whereas the broader macrofauna is less diverse than in the Hooken Member. Stratigraphic Significance: a major hiatus separates this Middle Cenomanian unit from the succeeding Pinnacles interval. Reworked older material occurs near its base, so an omission surface is not equivalent to absence of the whole Middle Cenomanian member. Interpretation: highly condensed shallow-marine limestone on a sediment-starved shelf, terminated by hardground formation and omission.

WHITE CHALK SUBGROUP

Holywell Nodular Chalk Formation (Late Cenomanian–Early Turonian)

Pinnacles Member (local condensed basal interval)

Bed HC13 — Pinnacles Glauconitic Limestone Interval And Haven Cliff Neocardioceras Hardground

The Pinnacles Member lies between the Humble Point and Haven Cliff hardgrounds. Its glauconitic limestone, nodules and phosphatised or reworked clasts record strong condensation. In the modern BGS scheme it is the basal part of the Holywell Nodular Chalk, above the Beer Head Limestone, and correlates broadly with the Plenus Marls and Melbourn Rock interval. The thicker Hooken development includes several internal hardgrounds, whereas elsewhere surfaces converge. At Haven, the named hardground and pebble-bed preserve direct fossil evidence, described individually below. Regional fossil lists and maximum thicknesses are not assigned indiscriminately to Haven blocks.

Humble Point Hardground
This surface caps the Beer Head Limestone and forms the base of the Pinnacles interval in the modern framework. The place name identifies a correlation marker, not proof that its entire type development is exposed at Haven.

Haven Cliff Hardground and Neocardioceras Pebble-Bed
At Haven, glauconitised pebbles on the hardground contain the terminal Cenomanian fauna, including Neocardioceras juddii, Sciponoceras, Thomelites serotinus, Mytiloides hattini and spines of Hirudocidaris hirudo. The reworked and condensed assemblage is important for correlation; it is not a claim that the lithological surface everywhere coincides exactly with a global time boundary.

Beer Head Thickness Note: The Historical Broad Formation Included Pinnacles; Current BGS Usage Excludes It. Hooken’s 10.4 m Maximum Is Not A Haven Measurement

Holywell above the Pinnacles interval: Connett’s Hole reference beds

HC14–HC16 retain the detailed White Cliff and regional Connett’s Hole succession. The 13.5 m measurement belongs to White Cliff west of Seaton. Exact Haven basal Turonian fossil records are distinguished from the western reference log below; no continuous Haven log is invented.

Bed HC14 — Lower Holywell Nodular Chalk Below The West Ebb Marl

Immediately above the Haven Cliff Hardground the chalk becomes hard, yellow-stained and nodular, with abundant shell detritus and a strongly condensed appearance. At White Cliff this lower Holywell interval expands much more than it does farther west, and in the wider Hooken–Wilmington system the lower part may pass laterally into the calcarenitic Beer Stone facies within the structural trough, although that freestone development is not present everywhere in the Haven Cliff sector. Typical Fossils: inoceramid debris and early Mytiloides, with other shelly fossils subordinate. Interpretation: lower Turonian chalk sedimentation on an uneven tectonic surface, locally still strongly influenced by reworking and hardground formation after the boundary condensation.

Basal Turonian fossil-bearing chalk at Haven
The GCR account specifically records Fagesia catinus, Kamerunoceras turoniense and Lecointriceras fleuriausianum from low Holywell-equivalent chalk at Haven. These are exact-local records; the richer regional Hooken echinoid list is not transferred here.

Bed HC15 — West Ebb Marl

The West Ebb Marl is a thin but regionally important marker bed within the lower Holywell Nodular Chalk. It provides one of the best practical correlation horizons through this otherwise laterally variable nodular chalk interval and separates lower nodular shell-detrital chalk from the more strongly condensed hardground-rich beds above. Interpretation: a brief increase in marl input and quieter pelagic deposition within an otherwise condensation-prone lower Turonian succession.

Bed HC16 — Upper Holywell Reference Beds, Branscombe Hardground And Flinty Hardground 5

Above the West Ebb Marl the chalk remains nodular and yellow-stained, with hardgrounds and sporadic flints toward the top. At White Cliff the full traditional Connetts Hole succession reaches about 13.5 m, but elsewhere it may thin to only a few metres or disappear completely, and the erosive Branscombe Hardground may cut out a large part of the higher Holywell interval. Where preserved, Flinty Hardground 5 marks the top of the historical Connett’s Hole Member above the Branscombe Hardground. Erosion may remove the intervening beds; the two surfaces must not automatically be treated as identical. Typical Fossils: abundant inoceramids including Mytiloides, with Orbirhynchia cuvieri characteristic in the broader facies. Biozone: Mytiloides spp. Zone. Interpretation: condensed lower Turonian open-marine chalk on a structurally active shelf, repeatedly interrupted by omission and hardground formation.

New Pit Chalk Formation (Turonian; White Cliff / Regional Reference)

Bed HC17 — Basal New Pit Chalk / Lower Beer Roads Flinty Chalk

In the historical White Cliff reference scheme, the Beer Roads Flinty Chalk begins at Flinty Hardground 5. Where erosion removes higher Connett’s Hole beds, the contact cuts down towards the Branscombe Hardground. The smoother marly chalk above contrasts with the nodular chalk below; small finger-like or spiky basal flints are described particularly at the Pinnacles in Hooken Cliff, and are not a bed-level identification established here at Haven. The Beer Roads reference facies is broadly equivalent to the Terebratulina lata Zone, but a single loose flint line cannot establish that correlation at Haven. Typical Fossils: inoceramids, brachiopods and sparse echinoid material; fossils are generally less concentrated than in the condensed nodular chalk below. Interpretation: more open-marine pelagic chalk deposition after a major break in sedimentation, though still influenced by local Devon flint development and structural control.

Bed HC18 — Main Beer Roads Flinty Chalk Interval

The main New Pit equivalent is a smooth white chalk with abundant small, spiky to nodular flints, wavy-bedded marly chalk intervals and marl seams. In the Devon coastal succession the local Beer Roads facies is more flinty than typical New Pit Chalk farther east in southern England, but the overall lithology remains that of marly white chalk rather than nodular condensed chalk. Regionally recognised marly or relatively flint-poor intervals occur within it, and this regional description can aid comparison of fallen material. An isolated Haven block is not assigned to a specific member or bed solely from the abundance of flint. Typical Fossils: Terebratulina lata, Inoceramus cuvieri and Labyrinthidoma are characteristic of the broader local facies. Biozone: Terebratulina lata Zone. Interpretation: open marine pelagic chalk sedimentation with periodic marl input and strong silica concentration, in the separate White Cliff and regional reference succession.

Chalk Thickness Note: No Combined Haven Total Is Assigned; White Cliff’s 13.5 m Connett’s Hole Record Is A Separate Reference Measurement

Higher Chalk Note

Higher Chalk occurs elsewhere along the east Devon coast, including the well-studied Hooken and Pinhay sections. Hooken lies west of Seaton and Pinhay lies east. Their fuller upper-Chalk logs are not inserted as a measured Haven succession. The limits of the present detailed account reflect the exact-local sources and the clearly labelled White Cliff comparison, not proof that younger chalk is absent from all Haven cliff or landslip material.

Depositional Environment

The Haven section, read alongside the explicitly separate western reference sections, records a major environmental sweep. The upper Mercia Mudstone Group represents arid continental mudflat, playa-margin and sabkha deposition with evaporitic influence; the Blue Anchor Formation records a grey-green dolomitic mudflat phase with increasing marine influence. After a major unconformity, the Upper Greensand records fully marine upper Albian sedimentation, passing upward from relatively deeper subtidal glauconitic sands of the Foxmould into shallower, high-energy chert-bearing calcarenites and cross-bedded sand bodies of the Whitecliff Chert and Bindon Sandstone members. The Beer Head Limestone is a highly condensed shallow-marine Cenomanian succession rich in hardgrounds and omission surfaces, and the succeeding Holywell and New Pit framework records latest Cenomanian and Turonian marine chalk deposition, still strongly modified in Devon by local tectonic control, condensation and lateral facies change.

References

Barton et al. (2011), Geology of south Dorset and south-east Devon and its World Heritage Coast
Gallois (2001), The stratigraphy of the Mercia Mudstone Group of the south Devon coast
Newell (2024), UK Stratigraphical Framework Series: Mercia Mudstone Group, BGS OR/24/046
BGS Lexicon: Branscombe Mudstone Formation
Gallois (2004), The stratigraphy of the Upper Greensand of south-west England
Wilkinson (2006), The holostratigraphy of the Albian Stage of the UK, BGS RR/06/01
Hopson (2005), A stratigraphical framework for the Upper Cretaceous Chalk, BGS RR/05/01
BGS Lexicon: Beer Head Limestone Formation
Mortimore, Wood and Gallois (2001), GCR Hooken Cliff account, including Haven and White Cliff comparisons