compiled by Mike Horne F.G.S.

A list of glacial erratics found on field meetings of the Hull Geological Society or records contributed by members.

In the early days of the Society there was a "Boulder Committee" which recorded erratics in East Yorkshire and published the details. Other Societies did similar work and this led to a greater understanding of the directions of ice movement during the Ice Age. The "Boulder Committee" was revived for the Society's centenary in 1988 and a report published (Harrison and Horne 1992), which lists erratics found and gives further details of the survey.

The reader should be aware of possible biases in the actual recording. The original surveys in the early 1900s only recorded large boulders. The present surveys record all erratics over 2cm dia (approx.). Also the recording reflects the recorders ability to recognise and name particular rock types in the field. So the list may reflect the abilities of the people on a particular field meeting. There may be a tendency to use some names in a generic way - for instance Lithostrotian may be used to record any Carboniferous colonial coral in some instances. Specimens are not normally collected so it is not possible to verify the identifications.

The localities are listed alphabetically, rather than geographically. The erratics are listed in the order they were recorded to give a rough idea of how common they are: the erratics towards the end of each list are less numerous at that locality.

Aldborough going north to Cowden - Arnioceras, red flint, red sandstone, Chalk, Acroteuthis, grey flint, black flint, Larvikite, brown sandstone, pink gneiss, pyrite crystals (common), New Red Sandstone, Dactylioceras tenuicostatum, Cardinia, Harpoceras, Carboniferous Limestone, Gryphaea, Hibolites, yellow quartz, white quartz, Exogyra, red granite, Speeton Clay cementstones, dogger with ammonite, Dactylioceras commune, Lithostrotion, pegmatite, red chalk, Asteroceras, Kimmeridge Clay, Jurassic belemnite, gabbro, Upper Cretaceous belemnite, Belemnitella mucronata, Cannon Ball Limestone, gneiss, Tilberthwaite Tuff, jasper, dogger, septarian nodules, Brockram, gneiss, pyrite, Nautilus, Middle Jurassic sandstone, Echinocorys in Chalk, ? Compound Nodule Bed (from Speeton Clay), coal, dolerite, Oxyteuthis, Pentacrinus, pink granite, vesicular basalt, beef, carnelian, crinoidal Carboniferous Limestone, Shap Granite.

Aldborough going south - Chalk, Gryphaea, Jurassic oyster bed, shale, grey flint, Pseudomytiloides dubius, Liassic ammonite, ?Ginkgo, Pentacrinus, coal, Hibolites, Kimmeridgian ammonite in shale, septarian nodule, Dactylioceras commune, Exogyra, Oxyteuthis, fossil bone, Belemnitella mucronata, beef, pyrite, jasper, green jasper, Larvikite, carnelian, Bunter Sandstone, Acroteuthis, Whin Sill, pyritised fossil wood, Frosterley Marble, black flint, Cardinia, red chalk, Arnioceras, Lithostrotion, Asteroceras, Exogyra, red flint.

Atwick (going north) - yellow quartz, coal (common), Chalk, jasper, Gryphaea, Carboniferous Limestone with solitary coral, Lithostrotion, red flint, black flint, Middle Jurassic sandstone, Jurassic oyster bed, Pentacrinus, Dogger, clear quartz, rhomb porphyry, milky quartz, red granite, pink granite, green conglomerate, ironstone, Jurassic ammonite, purple micaceous fine-grained sandstone, fossil wood, Old Red Sandstone, Dactylioceras commune in ironstone, Exogyra, Kimmeridge Clay with ammonites, 'Cheviot' porphyry, black Carboniferous Limestone, echinoid in black flint, New Red Sandstone, coral in soft Chalk, sponge in flint, septarian nodule, Terebratulid in Chalk, Belemnitella mucronata, Larvikite, basalt, vesicular basalt, ? Conulus in red flint, pink chalk, Oxfordian belemnites in grey clay.

Barmston (going north) - yellow quartz, black flint (common), red granite, Jurassic oyster bed, Lithostrotion, Productus, Dogger, Chalk, Middle Jurassic sandstone, red banded rock, Inoceramus, red flint, coal, Gryphaea, rhomb porphyry, Old Red Sandstone, biotite gneiss, garnet schist, ammonites, Cardinia.

Barmston (going south) - black flint (common), yellow quartz, Jurassic oyster bed, Old Red Sandstone, ammonite, Jurassic fossil wood, red veined rock, gabbro, Middle Jurassic sandstone, red flint, crinoidal Carboniferous Limestone, gneiss, Chalk, Lithostrotion, New Red Sandstone, Larvikite, rhomb porphyry, green conglomerate, jasper, Gryphaea, Middle Jurassic rootlet bed, black Carboniferous Limestone.

Bridlington -South Bay - Kimmeridge Clay, pink granite, yellow quartz, Jurassic Sandstone, Old Red Sandstone, gneiss, red quartz, black flint, Chalk, grey flint, Carboniferous Limestone, shelly Jurassic limestone, Gryphaea.

Carnelian Bay (northern part) - pale Jurassic oolitic limestone, Cheviot porphyry, yellow quartz, Lithostrotion, rhomb porphyry, grey granite, jasper, crinoidal Carboniferous Limestone, granite, white quartz, Larvikite, agate, carnelian, Dactylioceras.

Carnelian Bay (southern part) - rose quartz, Cheviot porphyry, jasper, Gryphaea, rhomb porphyry, grey flint, white quartz, yellow quartz, grey granite, red sandstone, Pentacrinus, Larvikite, Brockram, Dactylioceras.

Cayton Bay - Old Red Sandstone, Gryphaea, red porphyry, basalt, 'Cheviot' porphyry, Carboniferous Limestone, grey granite, purple amygdaloidal lava, septarian nodule, Middle Jurassic rootlet bed.

Cowden - Chalk, Upper Cretaceous belemnite, pink chalk, grey flint, white quartz, jasper, brown sandstone, shelly Jurassic limestone, rhomb porphyry, yellow quartz, gneiss, Lithostrotion, red flint, Harpoceras, Carboniferous Limestone, ammonite, septarian nodule, Old Red Sandstone, Jurassic belemnite, Speeton cementstone, Pectinid in dogger, Exogyra, Gryphaea, red granite, coal, Middle Jurassic rootlet bed, ironstone, pyritised ammonites, Tilberthwaite Tuff, green jasper, Arnioceras, Shap Granite, Pleuromya, ?Neohibolites, Kimmeridge Clay, Acroteuthis, large Gryphaea, yellow quartz, pyrites, black flint, Modiolus, Frosterley Marble, B. mucronata, Asteroceras, Gigantoproductus, Mammoth tooth. Also Augen Gniess from Mappleton sea defences.

Dimlington (going north) - Lithostrotion, red flint, pale pink granite with large phenocrysts (but not Shap Granite), quartzite, jasper, serpentinite, dark pink granite, black flint (common), Jurassic septarian nodule, gneiss, white quartz, Middle Jurassic rootlet bed, Old Red Sandstone, crinoidal Carboniferous Limestone, New Red Sandstone, Carboniferous Limestone with Gigantoproductus, pyrite, Larvikite, red chalk, pink granite, ammonite, grey flint, Carboniferous Limestone with corals, Jurassic shelly limestone, dogger, yellow quartz, red rhomb porphyry, basalt, green jasper, pink chalk, green conglomerate, greenschist, large Echinocorys in flint, fossil wood, pyrite, dolerite, Brockram, 'Cheviot' porphyry, Tilberthwaite Tuff, Gryphaea (very rare) Frosterley Marble, Arnioceras, Corbicula fluminalis, Buccinum, Arctica islandica.

Easington (going south from Dimlington) - gneiss, red flint, chalk, grey flint, garnet schist, Dactylioceras commune (poor specimen), red rhomb porphyry, Lithostrotion, shelly Jurassic limestone, jasper, black flint, green conglomerate, grey granite, Old Red Sandstone, black ' Cheviot' porphyry, white quartz, red chalk, brown sandstone, yellow quartz, black shelly Carboniferous Limestone, Middle Jurassic rootlet bed, red granite, septarian nodule, carnelian, Cardinia (rare) , Gryphaea (rare), crinoidal Carboniferous Limestone, pink quartz, green jasper, pyrite.

Filey Bay (middle - north of Reighton Gap) - Old Red Sandstone, brown sandstone (common), Lower Jurassic shelly limestone, Middle Jurassic rootlet bed, rhomb porphyry (rare), pale grey flint, dogger, dolerite, vesicular basalt, milky quartz, red quartzite, brown flint, Lithostrotion, black shelly Carboniferous Limestone, Hildoceras, Larvikite, Gryphaea (rare), ammonite in cementstone, Nuculana ovum, coal, crinoidal Carboniferous Limestone, yellow quartz (rare), Brockram, Harpoceras, grey granite, rose quartz, ?New Red Sandstone, pink granite, 'Cheviot' porphyry (rare). [Note- as you get nearer Reighton Gap the 'Cheviot' porphyry and Gryphaea become more common.]

Fraisthorpe (going south) - jasper, black flint, porphyry, Larvikite, yellow quartz, basalt, coal, red Carboniferous Limestone with Productus, septarian nodules, red granite, gneiss, Chalk (rare).

Gembling gravel pit - well rounded chalk pebbles (common), yellow sandstone, grey flint, white flint, coal (common), grey sandstone, yellow quartz, white quartz, Old Red Sandstone, dolerite, red/brown flint, Ostrea (recent), Gryphaea, brown rhomb porphyry.

Holmpton north - Phylloceras , Eliganticeras, Harpoceras, Pleuroceras, Eugasiceras, several Dactylioceras, Arnioceras.

Hornsea going north - garnet mica schist, black flint, yellow quartz, chalk, Lithostrotion, granite, red flint, grey flint, Gryphaea in limestone, black shelly Carboniferous Limestone, grey porphyry, red porphyry, red sandstone, green conglomerate, Larvikite, Gryphaea (rare), gabbro, carnelian, yellow sandstone, septarian nodule, white quartz, crinoidal Carboniferous Limestone, Middle Jurassic rootlet bed, Cardinia.

Hornsea sea front - spotted rock, Cannon Ball Limestone, Carboniferous Limestone with corals, jasper, yellow quartz, Brockram.

Hornsea going towards Mappleton - Belemnitella mucronata, muscovite schist, Brockram, Lithostrotion, rhomb porphyry, Cheviot porphyry, black flint, grey flint, red flint, Chalk, gneiss, granite, jet, coal, Jurassic sandstone with plants, Larvikite, yellow quartz, Inoceramus in red flint, Gryphaea, agate, white quartz, mottled Bunter Sandstone, pink chalk, carnelian, Dactylioceras commune, soft blue chalk, garnet gneiss, Pentacrinus, Lower Jurassic belemnites, coal, Inoceramus in Chalk, Jurassic Pecten, Harpoceras, ?Thracia, green conglomerate, Plesiosaur vertebra, Acroteuthis, green jasper, Arnioceras, Oxyteuthis, Hibolites, jasper, oolitic limestone, Exogyra, black shale, Cardinia, New Red Sandstone, garnet biotite schist, Phylloceras, Jurassic Nautilus, Pleuroceras, Arnioceras, Datylioceras tennuicostatum, Kimmeridge Clay, Jurassic shelly limestone, pink granite, Cannon Ball Limestone, Tilberthwaite Tuff, septarian nodule, Pecten , Holaster in Chalk, orange agate, Jurassic sandstone with fossil leaves, black shelly Carboniferous Limestone, Millstone Grit, Middle Jurassic rootlet bed, B. mucronata, B. ? lanceolota. Also in situ Scrobicularia Clay.

Keyingham (new) Gravel Pit - red flint, brown sandstone, Gryphaea, Jurassic oyster bed, black flint, mica schist, Kimmeridge Clay, B. mucronata, ironstone, Lithostrotion, garnet schist, brown flint, Brockram, gneiss, grey granite. Old Red Sandstone, rhomb porphyry, red flint, New Red Sandstone, grey flint, white quartz, basalt, Whin Sill, coal, white quartz, yellow quartz, carnelian, brown sandstone, jasper, chalk bored by piddocks, Corbicula fluminalis, Buccinum, cockle shells, oyster shells, gastropods.

Mappleton (going south) - red flint, Chalk, black flint, granite, microgranite, Echinocorys in Chalk, biotite schist, Jurassic cementstones, green conglomerate, Jurassic oyster bed/shelly limestone, Lithostrotion, Larvikite (rare) , Cardinia, Gryphaea, rhomb porphyry, Middle Jurassic rootlet bed, crinoidal Carboniferous Limestone, Lepidodendron, Pecten, Micraster in black flint, Belemnitella mucronata, jasper, ammonite in Kimmeridge Clay, jasper, red chalk, pink chalk, belemnites, carnelian, basalt, fish vertebrae, Neohibolites, Red Chalk with Neohibolites, ?Simbirskites, Arnioceras, Dactylioceras commune, ironstone, Pholadomya, yellow quartz, milky quartz, Hibolites, Acroteuthis, fossil wood, Pentacrinus, pyrite, coal, grey flint, septarian nodules, Speeton Clay cementstones, pink chalk, pink granite, Pseudomytiloides dubius in shales, Middle Jurassic sandstone with mud cracks, Exogyra, Micraster, Oxyteuthis, Harpoceras, ammonite in dogger, large pyrite nodule in chalk, Hibolites , 'Cheviot' porphyry, onyx, Cannon Ball Limestone, black rhomb porphyry, amygdaloidal basalt, agate, white quartz, Brockram, basalt, red rhomb porphyry, Dactylioceras tenuicostatum, Frosterley Marble, brown flint, Speeton shrimp bed, large belemnite phragmacone (1" dia), Rhynchonellid, Jurassic oolitic limestone, Micraster in black flint, red Carboniferous Limestone with Lithostrotion, biotite schist, garnet-biotite schist, carnelian.

North Ferriby foreshore - Lithostrotion, Oxyteuthis, belemnite in Chalk, black flint, red flint, grey flint, Carboniferous Limestone with solitary coral, Jurassic ammonites, Pentacrinus, yellow quartz, Acroteuthis, Arnioceras, Cardinia, Gryphaea, red chalk, Kimmeridge Clay, Middle Jurassic rootlet bed, 'Cheviot' porphyry, jasper, Lower Jurassic Nautilus, ?Tilberthwaite Tuff, Liassic shelly limestone, Belemnitella mucronata.

North Landing - black flint, brown sandstone, Old Red Sandstone, brown flint, yellow quartz, crinoidal Carboniferous Limestone, basalt, red rhomb porphyry, cross bedded brown sandstone, granite, Brockram, red flint, Lithostrotion, 'Cheviot' porphyry, gneiss, white quartz, Whin Sill, pale grey granite, Gryphaea (very rare).

Osgodby Point - grey granite, 'Cheviot' Porphyry, green conglomerate, yellow quartz, coarse ortho-quartzite, porphyry, grey rhomb porphyry, Carboniferous Limestone, Gryphaea, dolerite, basalt, septarian nodule, Middle Jurassic rootlet bed, red granite, Old Red Sandstone, Brockram.

Ringborough (north) - Gryphaea, chalk, black flint, grey flint, Whin Sill, septarian nodule, red chalk, jasper, Old Red Sandstone, New Red Sandstone, gneiss, white quartz, Dogger, Oxyteuthis, Jurassic belemnite, fossil wood, Pyrite, Kimmeridge Clay, Middle Jurassic rootlet bed, pyrite in chalk, Harpoceras, brown sandstone, black shelly Carboniferous Limestone, large Gryphaea, Jurassic shelly limestone, jasper, pegmatite, rhomb porphyry, biotite gneiss, red flint, Brockram, basalt, Larvikite, yellow quartz, red Carboniferous Limestone with corals, Dactylioceras commune, quartzite, red conglomerate, Phylloceras, jet, Pentacrinus.

Robin Hoods Bay - Echinocorys in flint.

Sand-le-Mere - yellow quartz, grey quartz, brown sandstone, jasper, white quartz, Dogger, grey flint, chalk, Larvikite, Kimmeridgian septarian nodule, dolerite, grey granite, gneiss, garnet-biotite schist, Lithostrotion, Old Red Sandstone, shelly Jurassic limestone, rhomb porphyry, black flint, pink chalk, grey rhomb porphyry, green conglomerate, red granite, crinoidal Carboniferous Limestone, Dactylioceras commune, carnelian, Gryphaea in shelly limestone, amygdaloidal basalt, Asteroceras.

Scalby (going north) - yellow quartz, gneiss, 'Cheviot' porphyry, jasper, rhomb porphyry, Carboniferous Limestone with corals, crinoidal Carboniferous Limestone, Lithostrotion, Cardinia, belemnite, Gryphaea, Brockram, ?Shap Granite, 'Cheviot' granite, Dactylioceras, Old Red Sandstone, porphyry, Larvikite.

Scalby Bay - Larvikite, Carboniferous Limestone, 'Cheviot' porphyry, gneiss, jasper, Old Red Sandstone, basalt, dolerite, Gryphaea, Lithostrotion, Shap Granite, Jurassic shelly limestone, yellow quartz, white quartz, rhomb porphyry, green conglomerate, brown sandstone, Dactylioceras.

Scarborough South Bay - Brockram, Cheviot porphyry, gneiss, rhomb porphyry, grey granite, Gryphaea, crinoidal Carboniferous Limestone, red sandstone.

Selwicks Bay - Paramoudra flint, greywacke, Peterhead Granite, Carboniferous Limestone with Gigantoproductus, pyrite, septarian nodule, garnet gneiss, rhomb porphyry, yellow quartz, 'Cheviot' porphyry (common), gabbro, Jurassic rootlet bed, Carboniferous Limestone with crinoids, dolerite ('Whin Sill'), basalt, granite, dark ?jasper conglomerate.

Sewerby going towards Bridlington - micaceous brown Jurassic sandstone, basalt, mica schist, rhomb porphyry, augen gneiss with white augens, Acroteuthis, Lower Jurassic ammonite, Middle Jurassic rootlet bed, yellow quartz, Lithostrotion in red limestone, Cardinia, Gryphaea, Shap Granite [at TA2012568638], Exogyra.

Sewerby going towards Danes Dyke - rhomb porphyry, Brockram, yellow quartz, jasper, Jurassic plant bed, muscovite schist, basalt, syenite, ironstone, Cheviot porphyry,

Skipsea Withow - Lithostrotion, black flint (common), yellow quartz (common), red flint, chalk, shelly Jurassic limestone, crinoidal Carboniferous Limestone, jasper, red granite, 'Cheviot' porphyry, basalt, gneiss, Larvikite, Middle Jurassic sandstone.

Skipsea (going south) - Old Red Sandstone, Tilberthwaite Tuff, black flint, yellow quartz, dogger, shelly Jurassic limestone, gneiss, chalk, coal, Lithostrotion, pink granite, red rhomb porphyry, Brockram, Middle Jurassic rootlet bed, white quartz, Gryphaea in limestone, grey flint, red flint, Jurassic belemnite, black 'Cheviot' porphyry, pink chalk, brown flint, larvikite, Pentacrinus.

Skirlington (going south) - yellow quartz, jasper, black flint, Carboniferous Limestone, Middle Jurassic rootlet bed, basalt, Jurassic shelly limestone, dogger, purple rhomb porphyry, Shap Granite, gneiss, brown sandstone, grey flint, white agate, chalk, Jurassic belemnite, Old Red Sandstone, black rhomb porphyry, red rhomb porphyry, red flint, coal, ?obsidian, red 'Cheviot' porphyry, New Red Sandstone, brown flint, quartzite, Kimmeridgian septarian nodule, pink chalk, grey granite, Macoma baltica.

Speeton - Dogger (common), Jurassic oyster bed, Middle Jurassic Sandstone, grey gneiss, Larvikite, Chalk, Carboniferous Limestone, Lithostrotion, Brockram, 'Cheviot' porphyry, grey flint, Gryphaea, gabbro, septarian nodules, Middle Jurassic rootlet bed, yellow quartz, green conglomerate, jasper, coal, Kimmeridge Clay coal, Cannon Ball Limestone, red sandstone, Dactylioceras, rhomb porphyry, Tilberthwaite Tuff.

Spurn Point - milky quartz, black flint (common), Chalk, grey flint, rhomb porphyry, yellow quartz, jasper, Dogger, gneiss, septarian nodule, red flint, granite, Lithostrotion, Cheviot porphyry, basalt, Gryphaea, Larvikite, serpulid (perhaps from Speeton Clay), Echinocorys in black flint, pink granite, pink syenite, Holaster in grey flint, biotite schist, pink microgranite, vesicular rhyolite, gneiss, gabbro, Carboniferous Limestone with crinoids, brown sandstone, New Red Sandstone, grey porphyry, garnet biotite schist, Jurassic shelly limestone, garnet gneiss, pink quartz, Middle Jurassic rootlet bed, quartz conglomerate, Micraster in black flint, jet.

Thornwick Bay - black flint, red quartz conglomerate, Jurassic shelly limestone, cross bedded brown sandstone, jasper, brown flint, 'Cheviot' porphyry, basalt, dogger, white quartz, brown sandstone, Jurassic oolitic limestone, gneiss, yellow quartz, amygdaloidal basalt, red quartzite, ironstone, septarian nodule, pink chalk, grey rhomb porphyry, granite, red flint, green conglomerate, Old Red Sandstone, gabbro, biotite schist, calcrete.

Ulrome (going north) - black flint, Chalk, yellow quartz, meta-quartzite, milky quartz, Middle Jurassic sandstone, shale, Jurassic oyster bed, rhomb porphyry, ammonite, Larvikite, Lithostrotion, Gryphaea, gneiss, Cardinia, Middle Jurassic rootlet bed, jasper, Arnioceras, 'Cheviot' porphyry.

Welton-le-Wold (North Lincolnshire) - Old Red Sandstone, Whin Sill, belemnite, Chalk, red chalk, 'Cheviot' porphyry, gneiss, Neohibolites, Oxyteuthis (from Lincolnshire rather than Speeton Clay), red flint, yellow quartz, shattered chalk (unusual surface looking like broken egg-shell), B. mucronata, Carboniferous Limestone with crinoids, coal, Lake District green tuff, pale grey flint, brown sandstone, white quartz, black flint, limestone with Gryphaea.

Withernsea (going north) - white quartz, yellow quartz, jasper, Larvikite, belemnite in Lower Jurassic Limestone, Lithostrotion, garnet gneiss, septarian nodule, black flint, red flint, pink quartz, Gryphaea, Hildoceras, Chalk, rhomb porphyry, green conglomerate, folded grey gneiss, New Red Sandstone, red granite, vesicular basalt, Peterhead Granite, Old Red Sandstone, Gigantoproductus, Frosterley Marble, dogger, Cannon Ball Limestone, Arnioceras, Kimmeridge Clay, Jurassic rootlet bed, red siltstone.

Compiled by M Horne from records of Hull Geological Society field meetings and own observations, with contributions by Tony Barker, Gordon Binns, Anne Horne, Stuart Jones, Stefan Ramsden, Harold Tabiner, and Nigel Whittington.

References/further reading :

Harrison R & Horne M 1992. The East Yorkshire Boulder Committee, report for the years 1987 to 1991. Humberside Geologist 10, 18-22.

Horne M 1992. Starting Geology in East Yorkshire. Humberside Geologist 10, 13.

Horne M 2000. Report of the East Riding Boulder Committee 1992 to 2000. Humberside Geologist 13, 42-45

Rockett T 1992. Glaciation and the Yorkshire Coast. Humberside Geologist 10, 14.

Published in Humberside Geologist 14 in 2006

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