Bowleaze Cove Fossil Hunting

1826 – early geological description of the coast
Adam Sedgwick’s description brought the Bowleaze–Redcliff part of the western Osmington coast into formal geological study. It helped establish that these cliffs and foreshore exposures were not just isolated collecting spots, but part of an Oxfordian reference section with Oxford Clay and overlying Corallian rocks.

1877–1895 – first detailed stratigraphy recorded
Blake and Hudleston, Damon and H.B. Woodward produced the first full 19th-century descriptions of the succession. Their work recorded the Furzy/Jordan Cliff clays, the Redcliff beds and the fossil oysters, ammonites and bivalves that later workers used to define the named local units.

1900 – major failure east of Bowleaze Cove described
A large upper-slope failure east of Bowleaze Cove showed how unstable the Corallian rocks and underlying clays are between Bowleaze and Redcliff. The failure helped explain the natural boulder armour on the shore and why fresh fossil-bearing blocks and disturbed clay are repeatedly supplied by cliff movement.

1923–1925 – Upper Oxford Clay subdivision set out
S.S. Buckman made the first detailed stratigraphical division of the Furzy Cliff Upper Oxford Clay, separating clays with Quenstedtoceras, the large-oyster Jordan Cliff Beds with Gryphaea dilatata, and the nodule-bearing Red Beds. This gave collectors and geologists a usable bed-by-bed framework for the fossiliferous clays at Furzy Cliff and Bowleaze.

1923–1926 – Furzy Cliff theropod described
Friedrich von Huene described the partial theropod skeleton collected from the Jordan Cliff/Furzy Cliff Oxford Clay as Megalosaurus parkeri. The specimen, including vertebrae, pelvic bones and hind-limb material, later proved to be one of the most important Oxfordian dinosaur fossils from Britain.

1929–1948 – type ammonites established from Bowleaze and Redcliff
Work on the Oxfordian bivalves and ammonites fixed the importance of fossils from this exact stretch. The Bowleaze Clay yielded holotypes including Peltoceras (Peltomorphites) hoplophorous, Cardioceras (Vertebriceras) altumeratum and Goliathiceras (Pachycardioceras) anacanthum, while Redcliff and the Preston Grit yielded type or figured ammonites such as Cardioceras (Cardioceras) persecans, Cardioceras (Cardioceras) cautisrufae and Cardioceras (Subvertebriceras) zenaidae.

1953 – Redcliff Point microfossil fauna described
Tom Barnard described foraminifera from the Upper Oxford Clay exposed in the upfaulted block at Redcliff Point. The account listed 23 species, including four newly described forms, and showed that the clay at Redcliff had value for micropalaeontology and bed correlation as well as for larger ammonites, oysters and reptile remains.

1955–1958 – Bowleaze Cove Quaternary deposits documented
J.N. Carreck, with A.G. Davis on non-marine molluscs, described the Quaternary deposits at Bowleaze Cove, recording faunal and floral evidence and early archaeological material; further faunal records from the Early Holocene Loam followed in 1958. This put the cove’s younger fossil record, including mammal-bearing material known from the River Jordan area, alongside its better-known Jurassic cliffs and foreshore.

January 1964 – rotational slip at Furzy Cliff
A rotational slip at the western end of Furzy Cliff was recorded in January 1964. The event demonstrated the rapid cliff-top retreat and slope failure that control exposure of Oxford Clay here, periodically renewing fossil-bearing clay while also making the undercliff unstable.

1964 – Metriacanthosaurus named
Alick Walker reassessed Huene’s dinosaur and named the new genus Metriacanthosaurus, making the Furzy Cliff specimen the type of Metriacanthosaurus parkeri. This gave the locality a named dinosaur based on Oxfordian theropod material, a rare record for the British marine Jurassic.

1971 – Bowleaze–Redcliff landslip complex reactivated
Another major upper-slope failure east of Bowleaze Cove reactivated the landslip complex between the cove and Redcliff Point. During the 1970s a staircase of slide blocks developed inland of the cliff edge, illustrating why the foreshore changes after wet weather and why fossiliferous blocks can appear in new positions.

1972–1974 – Furzy Cliff marine reptiles recorded
Ichthyosaur and plesiosaur material from the Jordan Cliff Clay was collected in 1972–1973 and recorded in 1974 by J.C.W. Cope. The ichthyosaur included 34 dorsal centra and five caudal centra with neural spines and ribs, tentatively referred to Ophthalmosaurus sp.; the find is important because Oxfordian ichthyosaurs are exceptionally uncommon in Britain.

1975 – Corallian trace fossils used to read the environment
Franz T. Fürsich’s work on Corallian trace fossils placed the burrows seen in fallen blocks between Bowleaze and Redcliff into environmental context. Common foreshore traces such as Diplocraterion, Thalassinoides and Rhizocorallium became useful evidence for changing shallow-marine energy conditions, rather than just attractive markings on boulders.

1983 – major landslip exposed a measurable Furzy Cliff section
A major landslip at Furzy Cliff exposed a continuous 24 m section of Upper Oxford Clay behind the slip plane and cleaned tilted beds on the shore. This allowed the first accurate bed-by-bed measured section of the Furzy/Bowleaze clays, turning a difficult slumped cliff into a precise stratigraphic reference point.

1985 – sea defences reduced access to the Jordan Cliff Clay
Sea defences built at Furzy Cliff made much of the Jordan Cliff Clay type locality inaccessible. The remaining small exposure at the eastern end of the defences and the northern side of Redcliff Point became especially important for seeing Gryphaea dilatata, Modiolus bipartitus and other fossils from the unit.

1986 – Bowleaze Clay and Red Nodule Bed redefined
J.K. Wright introduced the Bowleaze Clay name for the former Red Beds and showed that the Red Nodule Bed is a thin, 0.35 m unit within it, not a thick separate division. The work tied superbly preserved Cardioceras, perisphinctids and other fossils to precise beds and recorded a distinctive Mirosphinctes-type ammonite fauna of national importance.

1995 – Furzy Cliff reptile importance recognised
By the mid-1990s, Furzy Cliff was recognised as Britain’s best Oxfordian reptile locality. That status rests on a small but exceptional record: Metriacanthosaurus parkeri, semi-articulated Ophthalmosaurus-type ichthyosaur material and plesiosaur remains from the Upper Oxford Clay.

1995–1999 – Redcliff Point stage-boundary section clarified
Detailed work at Ham Cliff, on the Redcliff Point end of the section, showed that the Oxford Clay there spans the Callovian–Oxfordian stage boundary in an expanded, ammonitiferous sequence. This made Redcliff Point important for wider Jurassic correlation, with ammonites such as Quenstedtoceras and Cardioceras linking the beds to the base of the Oxfordian Stage.

2001 – Oxfordian reference coast and World Heritage setting recognised
The Bowleaze–Redcliff exposures were confirmed as part of the western end of the Bowleaze-to-Ringstead Oxfordian reference coast, and the same year the Dorset and East Devon coast became a World Heritage landscape. Locally, this linked the fossiliferous Oxford Clay, Corallian trace-fossil blocks and active landslips to an internationally important protected geological coast.

2016 onwards – renewed mass movement between Bowleaze and Redcliff
Cliff movement between Bowleaze Cove and Redcliff Point has been considerable since 2016, especially in the slipped Corallian slopes above the boulder-strewn foreshore. The renewed movement continues to expose trace-fossil-bearing sandstone and limestone blocks, but it also keeps the beach rough and makes walking below the cliffs hazardous.

Section Architecture

This is not a single simple cliff log. The useful geology is distributed along the low cliff from Bowleaze Cove eastwards toward Redcliff Point, with additional structurally repeated Oxford Clay on the north side of Redcliff Point and a published rotated landslip block at Redcliff that preserves the lower Osmington Oolite succession. The cliff is heavily affected by rotational slipping because permeable limestones and sandstones rest on softer mudstones, so large blocks are tilted, detached and moved downslope onto the beach.

Scope Note

This page deliberately excludes Furzy Cliff and does not attempt to log the fuller Furzedown Clay section farther west. It is restricted to the Bowleaze Cove cliff, the tract eastward to near Redcliff Point, and the structurally repeated and landslip-affected ground around Redcliff itself.

Structural Note

Small faults, local steep dips and landslip cause partial repetition of the Oxfordian succession in this tract. The Weymouth Member is seen both at Bowleaze Cove and again around Redcliff Point, and the lower Osmington Oolite is best known not from a clean upright cliff but from a rotated slipped block published from Red Cliff. The section therefore has to be treated honestly as a composite and partly repeated coastal exposure rather than as one continuous face.

ANCHOLME GROUP

Oxford Clay Formation (Lower Oxfordian)

Weymouth Member

Bed BC1 – Lower Bowleaze Clay Below The Red Nodule Bed (about lower 8 m of the 14.5 m Bowleaze Clay succession)

The Bowleaze Clay underlies the landslipped cliff between the sea-defence works and the holiday-camp tract at Bowleaze Cove. Its base is marked by a persistent band of white elliptical limestone nodules, above which lie several metres of very fine pale grey clay containing nests of oysters, especially Lopha gregaria and Liostrea. Higher in the lower part of the unit, dark sandy carbonaceous clays recur as sharp incursions into the paler mudstones and are remarkable for intense interburrowing between light and dark sediment. These beds have yielded abundant cardioceratid ammonites and a distinctive perisphinctid fauna. Ammonites: the base of the Bowleaze Clay still lies within the bukowskii Subzone of the Cordatum Zone. Depositional Environment: mainly quiet offshore mud deposition below fair-weather wave base, interrupted by storm-surge or storm-wash incursions carrying fine quartz sand and carbonaceous plant debris into deeper water.

Bed BC2 – Red Nodule Bed (c. 0.35 m)

This is the most distinctive marker horizon within the Bowleaze Clay and lies about the middle of the unit. It is defined by two closely associated nodule bands composed of dense buff to red-weathering sideritic concretions, commonly with septarian cracks infilled by calcite. Fossils include Modiolus bipartitus, Pleuromya alduini, oysters including Gryphaea preserved in life position, and other bivalves concentrated in or around the concretions. Marker-Bed Significance: the Red Nodule Bed records very slow sedimentation, early siderite precipitation and condensation within the Bowleaze Clay succession, and is one of the most useful practical datums in the cliff.

Bed BC3 – Upper Bowleaze Clay Above The Red Nodule Bed (c. 6 m)

Above the Red Nodule Bed the Bowleaze Clay returns to predominantly pale grey, very fine-grained clay that becomes increasingly calcareous upward. Dark storm-incursion beds become less important, and macrofossils are generally less conspicuous than in the lower part, although ammonites still occur and the unit remains faunally important. This higher part of the Bowleaze Clay has yielded rare and distinctive Oxford Clay ammonites, including forms that made the locality important in classic British cardioceratid work. Ammonites: the higher Bowleaze Clay belongs to the costicardia Subzone of the Cordatum Zone. Interpretation: reduced clastic influx and very low sedimentation on an offshore muddy shelf immediately before the abrupt sandy transgression of the Corallian above.

Bed BC4 – Jordan Cliff Clay Repeated Around Redcliff Point (c. 9 m)

On the north side of Redcliff Point the Oxford Clay reappears structurally as the Jordan Cliff Clay, represented by about 1 m of fissile lower clay and about 8 m of tough blocky silty clay above. These beds are more silty and more strongly blocky than most of the Bowleaze Clay and contain abundant Gryphaea dilatata, commonly encrusted by serpulids, together with frequent Modiolus bipartitus and crushed cardioceratids. The reappearance of this unit around Redcliff Point is a good example of the way local structure and landslip complicate the coast. Ammonites: Jordan Cliff Clay is correlated with the bukowskii Subzone of the Cordatum Zone. Depositional Environment: shallow offshore calcareous mud accumulation with a comparatively well-developed benthic epifauna and increasing silt input.

CORALLIAN GROUP

Redcliff Formation (Middle Oxfordian)

Redcliff Formation Note

The Redcliff Formation is about 29.2 m thick in the district, but only part of that thickness is cleanly exposed in the Bowleaze–Redcliff tract. The lower boundary on Oxford Clay is a sharp erosive non-sequence, though the very best exposure of that surface lies just beyond the present limits at Ham Cliff. Within this page the formation is represented by the upper part of the Nothe Grit, the Preston Grit at its top, much of the Nothe Clay, and the Bencliff Grit largely as low foreshore outcrop and fallen blocks beneath Redcliff.

Nothe Grit Member

Bed BC5 – Main Nothe Grit Member West Of Redcliff Point (upper two-thirds most clearly exposed)

The Nothe Grit at Bowleaze–Redcliff is a grey, yellow or brown fine-grained argillaceous sandstone in medium to thick beds, strongly bioturbated and commonly forming resistant ledges in the low cliff. Large calcareous concretions are characteristic, and trace fossils such as Thalassinoides and Rhizocorallium are conspicuous on weathered faces and fallen blocks. Oysters, serpulids and ammonites occur locally, and the best ammonite-bearing concretions have yielded Cardioceras cordatum and Cardioceras persecans. Interpretation: abrupt transgressive replacement of Oxford Clay offshore mud by sandy offshore to subtidal shelf sediment, with intense burrowing and repeated shell concentration.

Bed BC6 – Preston Grit (upper c. 1.5 m of the Nothe Grit succession)

The uppermost part of the sandy lower Redcliff succession is the Preston Grit, seen in the highest part of the low cliff from the Bowleaze holiday-camp tract toward Redcliff Point. It is a medium-grained shelly calcareous sandstone, commonly rich in bivalves and trace fossils, and has yielded frequent ammonites including Cardioceras cautisrufae and Cardioceras zenaidae. Although now generally treated as the uppermost part of the Nothe Grit Member rather than as a separate formal member, it remains a very useful practical field unit. Interpretation: rapidly accumulated, turbulent shallow-water sand sheet deposited after a break and slight uplift, in conditions shallower and more energetic than the main Nothe Grit below.

Nothe Clay Member

Bed BC7 – Nothe Clay Member At Redcliff (lower c. 8 m visible of c. 12 m total)

The Nothe Clay at Redcliff consists of fine, plastic grey mudstone alternating with sandy, bioclastic and locally ooidal limestone beds. The lower c. 8 m of the member can be examined here, while the higher part is commonly obscured by landslip and vegetation. Shell-rich limestones are common, bivalves are abundant, and the lithology contrasts strongly with the more uniformly sandy Nothe Grit below and Bencliff Grit above. Interpretation: a renewed deepening phase in which muddier sediment accumulated over the Redcliff shelf, punctuated by shell-sand incursions and thin more calcareous events.

Bencliff Grit Member

Bed BC8 – Bencliff Grit Member Beneath Redcliff (mainly represented by fallen blocks and low foreshore outcrop)

In this restricted tract the Bencliff Grit is not usually seen as a simple upright cliff section. Instead, it is represented chiefly by large fallen or slipped blocks and low foreshore ledges beneath Redcliff. The lithology is a fine-grained argillaceous sandstone to sandy siltstone with erosive bases, conspicuous bioturbation, and sedimentary structures including swaley cross-stratification, planar lamination and ripple lamination. Large calcareous concretions are common, and trace fossils are especially well developed on fallen blocks. Interpretation: regressive or falling-stage sandy shelf sedimentation in which storm-generated sand bodies prograded across the muddier Nothe Clay sea floor.

Contact Note – Redcliff Formation To Osmington Oolite Formation

The top of the Redcliff Formation is a sharp erosive surface beneath the basal Osmington Oolite. In the Bowleaze–Redcliff tract this contact is most realistically understood from rotated landslip blocks and fallen masses rather than from a clean in-situ cliff face. The change is nevertheless very marked: sandy storm-influenced clastics below give way upward to ooid-rich and micritic carbonates of the lower Osmington Oolite.

Osmington Oolite Formation (Middle Oxfordian)

Osmington Oolite Note

At Redcliff the lower Osmington Oolite is best documented from a published rotated landslip block. The beds below are therefore real published Redcliff beds, but they should not be mistaken for an undisturbed upright cliff section. The block begins in the upper part of the Upton Member and continues upward through the Shortlake Member, preserving one of the most useful local logs for the top of the Redcliff Formation and the base of the Osmington Oolite west of Black Head.

Upton Member

Bed BC9 – Wright Bed 1, Upper Upton Member Nodular Micritic Limestone (0.45 m seen)

This basal bed of the published Redcliff block is a nodular micritic limestone with very scattered coarser ooids, numerous immature finer ooids and thin curving burrows. It represents the upper part of the Upton Member rather than its full local thickness. The bed is more argillaceous and more muddily micritic than the cross-bedded oolites above, and shows that the return to carbonate sedimentation at Redcliff began in relatively quiet, deeper-water conditions. Ammonites: the Redcliff Upton fauna belongs to the lower Antecedens Subzone.

Bed BC10 – Wright Bed 2, Medium Grey Silty Mudstone With Scattered Ooids (0.50 m)

A thin but distinctive ooid-bearing silty mudstone overlies Bed 1. The mixed muddy and weakly ooidal fabric is typical of the transitional deeper-water facies of the Upton Member in this western part of the Corallian tract. It indicates continued offshore deposition, but with ooids already being supplied into the mud-dominated system.

Bed BC11 – Wright Bed 3, Nodular Calcareous Mudstone With Six Nodule Bands (1.30 m)

This is one of the clearest Upton beds in the Redcliff block: a nodular calcareous mudstone with six bands of nodules made largely of micritic limestone containing scattered ooids, and with ooid-filled burrows in places. The repeated nodule bands show episodic cementation within a predominantly muddy sea floor. The bed is strongly bioturbated and represents a quiet offshore carbonate-mud environment with intermittent benthic activity.

Bed BC12 – Wright Bed 4, Sandy Marl With Ooidal And Shelly Grains (1.15 m)

A sandy marl containing ooidal and shelly grains, together with two bands of nodular argillaceous micrite, closes the Upton interval in the Redcliff block. Compared with the beds below, it is clearly more sandy and shallower in aspect, foreshadowing the ooid-dominated Shortlake Member above. Interpretation: upward shallowing from offshore calcareous mud into a more agitated shelf or ooid-sand setting.

Shortlake Member

Bed BC13 – Wright Bed 5, Coarsely Shelly Oomicrite (0.40 m)

The lowest Shortlake bed in the Redcliff block is a coarsely shelly oomicrite. It marks the clear entry into more strongly ooidal carbonate sedimentation and contains a conspicuous shelly component. The Shortlake Member at Redcliff belongs to the uppermost Antecedens Subzone and records a shallower, more agitated phase than the Upton beds below.

Bed BC14 – Wright Bed 6, Densely Ooidal Micrite (0.65 m)

This rubbly-weathering, densely ooidal micrite is one of the most easily recognisable Shortlake lithologies in fallen blocks. It is much richer in ooids than the Upton beds and is typical of the ooid-delta and shoal facies that characterize the Shortlake Member in westward Corallian facies. The high ooid content points to repeated agitation in very shallow marine water.

Bed BC15 – Wright Bed 7, Mudstone With Nanogyra nana (0.15 m)

A thin but fossiliferous mudstone containing Nanogyra nana interrupts the ooid-rich carbonates. This bed demonstrates that very shallow ooid shoals and quieter muddy shell-bearing phases alternated repeatedly within the Shortlake Member, rather than the member being one single uninterrupted oolite body.

Bed BC16 – Wright Bed 8, Cross-Bedded Very Poorly Sorted Oosparite (1.90 m)

This thick oosparite is strongly cross-bedded and very poorly sorted. In the Redcliff cliff top and slipped blocks, similar beds commonly contain abundant shale pellets and other signs of scouring. It is one of the key shallow-water ooid-shoal units of the locality. Interpretation: migration of ooid sand bars or ooid-delta foresets under high-energy conditions, probably in a lagoonal to very shallow marine setting.

Bed BC17 – Wright Bed 9, Mudstone With Fissile Sandy Sparry Limestone Bands (0.70 m)

Above the cross-bedded oosparite lies a quieter mixed unit of mudstone with bands of very fissile, fine-grained, sandy sparry limestone. This bed records a short-lived pause in the main ooid-sand migration phase, with muddier sediment reappearing before another cross-bedded ooid body arrived.

Bed BC18 – Wright Bed 10, Upper Cross-Bedded Oosparite (1.30 m)

A second thick cross-bedded, very poorly sorted oosparite repeats the high-energy ooid-sand facies of Bed 8. These thick oosparites are among the most distinctive Redcliff beds and correspond to the strongly cross-bedded oolites described from the top of Redcliff. Typical Fossils: occasional cardioceratids and perisphinctids have been recorded from the Shortlake Member at Redcliff, including Cardioceras maltonense and perisphinctids close to Perisphinctes decurrens and P. dobrogensis.

Bed BC19 – Wright Bed 11, Shelly Ooidal Mudstone With Coarsely Ooidal Micrite Bands (0.70 m)

This bed returns to a muddier but still strongly ooidal facies, with shelly ooidal mudstone and bands or nodules of coarsely ooidal shelly micrite. The unit represents waning energy above the main cross-bedded ooid bodies while still remaining firmly within the shallow ooid-rich Shortlake regime.

Bed BC20 – Wright Bed 12, Nodular Shelly Limestone With Irregular Clay Partings (1.4 m seen)

The highest logged bed in the Redcliff block is a nodular limestone with irregular clay partings. Near the base it is more massive, coarsely ooidal and shelly, with well-preserved bivalves including pectinids, while higher parts become more nodular shelly micrite with scattered coarse ooids. This bed closes the published Bowleaze–Redcliff lower Osmington Oolite section and records a slight reduction in transport energy after the cross-bedded ooid bodies below. Scope Limit: higher Nodular Rubble and Clavellata beds are better exposed east of Redcliff Point and are not forced into this page.

Depositional Environment

The Bowleaze Cove–Redcliff Point tract records the transition from lower Oxfordian offshore mud into the sandy and ooidal shelf facies of the Corallian. The Bowleaze and Jordan Cliff clays of the Weymouth Member were deposited as calcareous offshore muds below fair-weather wave base, but the Bowleaze Clay was repeatedly disturbed by storm-borne incursions of carbonaceous sand and plant debris, and the Red Nodule Bed records a condensed sideritic horizon formed during particularly slow sedimentation. The Redcliff Formation marks an abrupt shallowing and influx of sand: the Nothe Grit represents bioturbated offshore to subtidal sands, the Preston Grit a more turbulent shallow-water shelly sandstone, the Nothe Clay a renewed deeper muddy phase with shell-bearing limestones, and the Bencliff Grit a prograding storm-dominated sand body. The lower Osmington Oolite at Redcliff records a further shift into ooid-rich carbonate sedimentation, beginning with muddier and more offshore ooid-bearing Upton facies and passing upward into the cross-bedded ooid shoals, bars and lagoonal to intertidal ooid-delta facies of the Shortlake Member.

Total Thickness Note

No honest single total thickness can be given for one unbroken cliff because the tract is structurally repeated and heavily landslipped. What can be stated securely is that the locality includes the full 14.5 m Bowleaze Clay, about 9 m of Jordan Cliff Clay around Redcliff Point, a substantial but incomplete exposure of the 29.2 m Redcliff Formation, and a published Redcliff landslip-block log of 3.4 m of upper Upton beds overlain by 7.2 m of Shortlake Member.

References

Wright, J.K. (1986). A new look at the stratigraphy, sedimentology and ammonite fauna of the Corallian Group (Oxfordian) of south Dorset.
Wright, J.K. (1986). The Upper Oxford Clay at Furzy Cliff and related Weymouth Member sections of south Dorset.
Wright, J.K. (2011). The ammonite faunas of the Osmington Oolite Formation (Jurassic, Middle Oxfordian) of the Dorset coast.
Wright, J.K. & Cox, B.M. (2001). Osmington and adjacent coastal sections, in British Upper Jurassic Stratigraphy (Oxfordian to Kimmeridgian), Geological Conservation Review Series.
Arkell, W.J. (1947). Geology of the Country around Weymouth, Swanage, Corfe and Lulworth.
British Geological Survey Lexicon of Named Rock Units: Oxford Clay Formation, Weymouth Member, Redcliff Formation, Nothe Grit Member, Nothe Clay Member, Bencliff Grit Member and Osmington Oolite Formation.
Goldring, R., Pollard, J.E. and co-authors on the ichnology and sedimentology of the Bencliff and Nothe grit successions.
Local Dorset field guides and Geologists’ Association excursion notes for Bowleaze Cove and Redcliff Point, used for exposure style and modern landslip context.