Beadnell

Eelwell limestone at NU 2366 2938–NU 237 294. Grey fossiliferous biomicrite has upper, buff-weathering levels particularly rich in bryozoans. Garwood’s 1893 account called the limestone at this place Beadnell or North Sunderland Limestone and gave a district-average figure of 24 ft. That historical average is not a modern measurement of the complete present Red Brae exposure, and the historical name cannot be equated with every “Beadnell Limestone” in other accounts.

Red Brae limestone structure. Bower describes open cylindrical folds with spacing of approximately 5–15 m, amplitudes around 2 m and southward plunges of 6–8°. East- to east-north-east-directed intrabed thrusts detach into shale partings. Cross-cutting and anastomosing strike-slip faults, together with calcite-filled tension-gash veins, record additional deformation. These values describe structures. The original printed account gives strike-slip displacement generally less than 2 m and fault traces persisting over 5 m; displacement and trace length are different measurements. Figure 91 independently captions a photographed displacement of less than 2 m.

Upper Eelwell posts at Dell Point. Several limestone posts were sampled separately, but Billing found no consistent vertical change in bryozoan composition. The exact-station list comprises Hyphasmopora buskii, Fenestella multispinosa, F. tuberculo-carinata, F. plebeia, Penniretepora flexicarinata, Synocladia sp., Tabulipora sp. and Sulcoretepora parallela. The illustrated Synocladia fragment DP 11 is a documented specimen, not a newly named species. The four separate Snook Point post assemblages are not imported into this station.

Brachiopod-rich mudstone above Eelwell. A relatively thin, dark grey calcareous mudstone contains abundant Eomarginifera and Spirifer in Billing’s account. Garwood used the historical names Producta longispina and Spirifera trigonalis for Red Brae shale fossils; these are not silently treated as one-to-one modern synonyms of Billing’s determinations. A storm-deposit interpretation was suggested using the bed’s continuity towards Snook Point. Fossil abundance alone does not prove that interpretation, and no exact local thickness is assigned.

Laminated shale and fine sandstone above Red Brae. The overlying clastic beds are gently warped into two north–south anticlines. They have wider spacing and lower amplitude than the limestone folds below, and Bower did not record equivalent thrusting in this interval. No bed-by-bed thicknesses are available.

Historical coal-bearing beds beneath Red Brae. Garwood described workable coal seams below the local limestone. This is a historical geological and mining observation, not present mine-access guidance. No reliable exact shore-seam thickness is supplied, and values from inland workings are not substituted.

Blyth or Blythe Rocks, Benthall and Nacker Hole. The limestone around NU 2360 2902 is the Acre, formally Three Yard, Member. Garwood called the bed at this station Six-yard. Bower recorded closely spaced open folds, approximately 2–5 m apart, with gentle southward plunges and thrust offsets of around 0.5–1 m. These are fold spacings and displacements, not an exact member thickness.

Ironstone-bearing black shale below Sandbanks. Garwood described black shale containing ironstone nodules on the northward, descending traverse. He compared it with the Brinkburn ironstone-bearing beds; that is a historical correlation, not a demonstrated new member or a measured local thickness.

Sandbanks limestone posts. The historical Eight-yard limestone corresponds here to the Sandbanks or Four Fathom Member. Several limestone posts are separated by shale. Billing’s 7–11 m range is regional and is not reported as the measured thickness of Lady’s Hole at NU 238 288.

Fossiliferous shale partings at Lady’s Hole. The shale samples are dominated by rhabdomesid bryozoans and fragmented colonies. Billing recorded Rhabdomeson gracilis, R. rhombifera, Rhombopora bancrofti, R. incrassata, Polyfenestella fenestelliformis, an indeterminate trepostome and Sulcoretepora parallela, together with brachiopod fragments. Specimen LH 4 of Polyfenestella was described in detail. These historical determinations belong to Lady’s Hole; neither numbered partings nor individual parting thicknesses were recovered.

Folded and thrust limestone posts at Nacker Hole. Folds with north-north-east to north-east axes and slight southward plunges reach amplitudes of about 1.5 m. Reverse displacements reach around 1.2 m. Vertical stylolites predate the thrusts, while later strike-slip movement offsets fold axes by up to 2 m and cuts the dyke. These relationships record distinct deformation stages rather than a single event or measured sedimentary thickness.

Intervening clastic beds towards Ebb’s Nook. Shale and sandstone occur below the Great Limestone and above the Sandbanks on Garwood’s coastal traverse. Their position is useful, but no complete measured local subdivision was recovered, so unnamed beds and numerical thicknesses are not invented.

Great or Dryburn limestone at NU 239 287. Massive fossiliferous limestone forms the harbour’s natural breakwater and Ebb’s Nook. Garwood recorded a south-east dip of around 8–10°; Bower found relatively little folding here compared with the northern reefs. The member is Pendleian, within the Serpukhovian, and lies at the top of the Alston Formation. Its exact complete present-day harbour thickness was not recovered.

Historical compound-coral band. Hodge explicitly cites the 1927 Geological Survey account of Lonsdaleia and other compound corals in a band approximately 3 ft above the limestone base at Beadnell harbour. This is a historical generic identification. It does not establish a modern species assignment or justify adding the Chaetetes, Calcifolium or Frosterley assemblages of other Great Limestone localities.

Nacker Hole mapped thin coal. Figure 90 marks a poorly exposed thin coal beside the road and wall. It has no printed measured thickness or verified named-seam correlation and is retained as a separate mapped observation.

Mapped cross-bedded sandstone beside the dyke. A medium-grained, cross-bedded sandstone is labelled between the Acre and Sandbanks exposures in Figure 90. It is a separately mapped clastic horizon; no numerical thickness is inferred.

Later intrusion and faulting. The igneous body cuts across the sedimentary succession and is treated separately from its members.

Beadnell dolerite dyke. The intrusion crosses the Acre and Sandbanks limestones and intervening clastic beds near Nacker Hole. Garwood’s average width was 25 ft, a historical dyke measurement rather than sediment thickness. Bower records branches or apophyses, folded limestone beside the intrusion and later faults that offset it.

Northern extension: Annstead and north Beadnell. These are separately identified comparison exposures, not beds demonstrated at the harbour pin. The following observations preserve their own locality and historical terminology.

Oxford Limestone at Annstead Rocks. Bower recorded four gently deformed open anticlines, with minor bed thrusts of less than 1 m displacement. Neither the fold count nor the displacement is a limestone-thickness log.

Unnamed thick limestone above Oxford. The higher carbonate shows weak, broad north–south flexing, without comparable folding and thrusting in the study. It is retained as an unnamed observed unit.

Historical Budle/Colwell limestone at north Beadnell. At structural station 52, NU 2326 2970, fault splays slice the limestone and interleave it with clastic rocks. A local anticline and strike-slip structures are recorded. Station 52 is a map locality, not Bed 52, and the older Budle/Colwell naming is not silently substituted into the revised microfaunal scheme below.

Lower unnamed thin limestone above the Budle interval. Bower recorded this as one of two distinct thin carbonate horizons. It was neither folded nor thrust in the described exposure; no member name or measured thickness is assigned.

Upper unnamed thin limestone. A second separate thin carbonate is also recorded without equivalent folding or thrusting. It is not merged with the lower horizon or given an invented formal name.

Thin coal and erosive sandstone lenses. Lens-shaped sandstone locally removes the coal. A later dextral strike-slip fault displaces the erosion surface, providing a relative sequence of deposition, erosion and deformation. No exact coal or sandstone thickness is given.

Regional Great Limestone comparison, not a harbour log. The following historical figures describe a wider coastal interval and remain outside the exact village measured evidence.

Historical Tumbler Beds. For the broader Embleton–Beadnell area, Hodge cites approximately 27 ft of massive limestone and around 20 ft of shaly and thin-limestone Tumbler Beds, with a stated total of 48 ft. The slight mismatch between the rounded components and total is retained rather than corrected by inventing a missing bed. These figures are not a measured present harbour column.

Microfossils and revised correlations: section-level evidence. Cózar and Somerville’s 2020 study uses thin-section microfauna to compare Beadnell, Spittal and other Northumberland sections. Its combined assemblages cannot be treated as a species list for every named beach bed. The sample-to-place supplement was not available for this account, so individual sample codes below remain attached to the published combined result rather than a guessed visitor station.

Oxford Limestone: combined Spittal–Beadnell record. The paper explicitly states that samples were productive in both sections. The combined assemblage includes Neoarchaediscus, Archaediscus at the angulatus stage, Howchinia gibba, rare H. longa, Falsocalcifolium punctatum and transitional Endothyranopsis crassa–E. sphaerica. The interpretation is upper early Brigantian, assemblage 6. This does not place every taxon in an individually identified Annstead bed.

Budle Limestone: revised Beadnell correlation. The 2020 paper identifies Budle as the third limestone above Oxford in its Beadnell section, records Asteroarchaediscus pustulus and correlates it with Lower Bath-House Wood at Spittal. This differs from older Colwell/Budle equivalences. Its scheme is retained separately rather than relabelling each old mapped bed.

Middle Bath-House Wood: separately named regional interval. The coastal study records Asteroarchaediscus bashkiricus and an unnamed new Praeostaffellina form. The exact sample station remains unresolved here; Middle Bath-House Wood is not assumed to mean one of the older Upper Bath-House Wood leaves.

Upper Bath-House Wood: combined coastal samples. The account records Archaediscus transitional from angulatus to tenuis stage and “Millerella” tortula, with sample Pc3606 illustrated. No exact Beadnell bed occurrence is inferred solely from the combined heading.

Shotto Wood: combined coastal samples. Janischewskina brigantiensis and Eostaffella mirifica, including illustrated sample Pc3607, support a late Brigantian assemblage 7 interpretation. Their precise local sample position is not established in this guide.

Eelwell: revised regional correlation. The study correlates Eelwell with the Five Yard Limestone rather than relying on the older Scar equivalence. Combined coastal records include Endothyranopsis sphaerica, Climacammina, Janischewskina typica, “Millerella” tortula, Eostaffella mirifica, an unnamed Praeostaffellina, Biseriella parva, Endothyranopsis plana and Howchinia with umbilical structures. Illustrated samples Pc3572, Pc3578, Pc3583 and Pc3568 are not assigned to Dell Point without the missing sample matrix.

Acre: combined Spittal, Beadnell and Boulmer evidence. Neoarchaediscus postrugosus, Eostaffellina decurta, Eostaffellina ex gr. paraprotvae, Eostaffella ex gr. pseudostruvei, Calcifolium okense, Eostaffellina ? sp. and Endothyranopsis sphaerica support the Three Yard correlation and assemblage 8. Samples Pc3556 and Pc3587 are illustrated, but the pooled result is not a complete species list for each of the three sections.

Sandbanks: combined coastal evidence. The Four Fathom correlation and assemblage 9 interpretation use Eostaffellina paraprotvae, Eostaffella pseudostruvei, Archaediscus at tenuis stage, Eostaffellina decurta and Eostaffella ex gr. pseudostruvei. Illustrated samples Pc3560 and Pc3590 are retained at combined-study scope, without assigning them to Lady’s Hole.