Queensferry Fossil Hunting

1888 – Newhalls white trap examined
Ernst Stecher published microscopic and chemical work on pale altered intrusive rock from Newhalls, near Queensferry. Relict igneous textures and its unusual composition helped establish the nature of the shore’s white trap.

1910 – An explanation for white-trap alteration
J. S. Flett recognised that the preserved igneous texture showed that the sills had solidified before their extensive alteration. He proposed that heating of the surrounding carbon-rich sediments released gases and solutions that changed the original minerals.

1911–1912 – The shore succession reinterpreted
Geological revision in 1911, published the following year, distinguished the Queensferry Cements from the Burdiehouse Limestone and correlated the marine band above the cements with the Pumpherston Shell Bed. The true Burdiehouse Limestone and Camps Shale nearer the bridge were recognised separately, correcting a major source of confusion in the local sequence.

1930 – White-trap chemistry investigated further
T. C. Day compared altered intrusive rocks from several Scottish localities, including the Dalmeny material from this shore. His chemical work developed a two-stage interpretation of their alteration.

1962 – The marine fauna documented
The published account of P. J. Brand’s collections from the South Queensferry marine band recorded brachiopods, gastropods, several bivalves and straight-shelled nautiloids. Shales above the band yielded Naiadites obesus and Euestheria, helping distinguish the marine and non-marine parts of the succession.

1987 – Stromatolitic dolostone compared across the basin
S. J. Maddox and J. E. Andrews compared the laminated and brecciated carbonate at South Queensferry with similar beds at Hopetoun and Burntisland. They proposed a correlation associated with widespread shallowing of the basin.

1989 – The Calders Member introduced
J. I. Chisholm, A. D. McAdam and P. J. Brand introduced the Calders Member in a revision of the regional stratigraphy. The shore from just east of the railway bridge to Longcraig Pier serves as its type section, giving these exposures a formal role in describing the oil-shale succession.

1998 – Organic-rich sediments analysed
B. Follows and R. V. Tyson studied the organic composition of a measured Queensferry foreshore section. Their work linked variations in organic matter to changing lake conditions, including quiet, oxygen-depleted water that favoured its preservation.

2003–2004 – Geological conservation accounts published
Detailed scientific accounts brought together the importance of the thin white-trap sills and the fossil-bearing sedimentary succession. They highlighted the shore’s value for understanding intrusive alteration, lake deposits, marine flooding and stratigraphic correlation.

2007 – Detailed lake-margin log published
N. S. Jones’s published sedimentological study documented a short South Queensferry succession from oil shale through laminated microbial limestone into wave-rippled sandstone. Stromatolitic domes, soft-sediment deformation and salinity-related cracks added detail to the interpretation of the changing lake margin.

The account runs from younger sedimentary rocks to older ones. Measurements describe particular published exposures, not a continuous modern survey of everything visible on a visit. The 1927 Queensferry–Whitehouse table spans a wider shore: only its bridge-to-Long Rib portion is described in detail here. Its original feet and inches are retained where that makes the source-specific subdivisions clear.

STRATHCLYDE GROUP

West Lothian Oil-Shale Formation

The local beds are Asbian. The wider formation and full Hopetoun Member span a longer interval, so their regional age ranges and thicknesses do not describe this short section. Older accounts use Lower and Upper Oil-Shale groups and Queensferry Beds; those terms belong to earlier classifications and are not extra units inserted into the modern hierarchy. Organic-rich mud accumulated in quiet lake waters, while deltaic sand supply, lake-level changes and occasional marine flooding created the varied succession.

Hopetoun Member

Dunnet Sandstone. The pale-brown to brown, fine- to medium-grained sandstone at the bridge is massive in places and cross-bedded elsewhere. Ochreous plant stems and debris, sand-filled Stigmaria rooting structures, rootlets and desiccation features record vegetation and exposed sediment surfaces. U-shaped burrows near the top have been interpreted as evidence of marine influence. The published thickness is about 90 m for the shore unit extending across the bridge, not the height of the accessible outcrop. Basal beds are locally steepened beside the fault. The 1927 table records 300 ft of sandstone followed by a fault with an estimated displacement of 5–10 fathoms; the latter is structural displacement, not an added sedimentary layer.

Camps Shale. Dark fissile oil shale lies above the Burdiehouse Limestone at Port Neuk and is only patchily exposed among the shingle. The exact-shore 1927 log gives 3 ft, approximately 0.9 m, including a pale ashy rib at its base. A fault places the Camps/Burdiehouse rocks against the bridge sandstone, interrupting the visible succession.

Burdiehouse Limestone. This hard grey to dark, banded lake limestone has a characteristic glassy fracture. Ostracods, fish remains and plant fragments are recorded. The 1927 description places it at low water about 80 yd east of the rail bridge and measures 5 ft, approximately 1.5 m; the later Scottish limestone memoir repeats that local thickness. The commonly quoted regional thickness of 6–9 m is not the measurement here. Modern molluscs have bored some low-water surfaces. The limestone’s base defines the boundary with the Calders Member below.

Calders Member

The shore from just east of the railway bridge towards Longcraig Pier is the member’s type section. This does not mean its full regional thickness is exposed at each stop. Above the Pumpherston interval and below the Burdiehouse Limestone, sandstone dominates a varied package with mudstone, siltstone and subordinate cementstone. Cross-bedding and other sedimentary structures indicate deltaic deposition; faults, the pale intrusions and covered ground disrupt a simple bed-by-bed traverse.

Upper Calders mudrocks and cementstone: the 1927 descending log. Directly below the Burdiehouse Limestone the historical section records 12 ft of mudstone; 2 ft of dark calcareous mudstone with small crustaceans, called “entomostraca” in the original; 33 ft of mudstone and ribs; a 1 ft yellow-weathering cementstone containing small worm tubes; and 19 ft of silty mudstone. These are separately recorded beds and intervals, not formal named members or proof of uninterrupted exposure today.

Upper Calders sandstones and intrusive sheets: the 1927 continuation. Below those mudrocks the log gives 42 ft of sandstone, a 2 ft pale-blue dolerite sheet, 93 ft of yellow sandstone, 11 ft 6 in of silty mudstone, a 2 ft white-trap sheet and a striped, irregular cementstone varying from 1 to 4 ft. The two igneous sheets are intrusions into the sedimentary succession. Their historical measurements and the later field descriptions below are retained separately rather than treated as an exactly remeasured continuous log.

Western altered dolerite sill. The later field guide describes an approximately 0.9 m pale-grey, brown-weathering sheet within the sandstone east of Port Neuk. Polygonal joints help distinguish it from the host sandstone; the dark baked sandstone underneath shows desiccation cracks. Its contacts locally cut across bedding.

Eastern white-trap sill and adjacent sandstone. The conspicuous cream-coloured sheet at the low headland is about 0.6 m thick, with brownish margins and baked carbonaceous mudrocks above and below. It is broadly sheet-like but transgresses bedding and encloses pieces of host rock. Carbonates and clay minerals have replaced much of the original dolerite, although microscopic igneous textures survive. About 1 m of pale-brown, fine-grained ripple-bedded sandstone lies between the sheet and the laminated carbonate interval. Small thrusts, slickensides and folded mudrocks record local deformation. No numerical emplacement age is established here for these thin sills.

Bogwood Limestone and stromatolitic cementstones. The carbonate-bearing cap above the Pumpherston mudrocks is named Bogwood Limestone in the geological conservation account. At the point east of Port Neuk, the field guide describes about 1.1 m of finely laminated cementstone, with rounded microbial domes near the top and a thin desiccation breccia lower down. Approximately 1 m is a useful field-scale thickness, allowing for the variation between published descriptions. These shallow-water structures record microbial growth and periodic exposure; they are distinct from the Burdiehouse Limestone higher in the succession. The older striped-cementstone measurement of 1–4 ft retains its own historical scope.

Later detailed section and the informal Port Neuk Sandstone. A South Queensferry section published by Jones in 2007 gives additional detail through the upper Pumpherston mudrocks, microbial limestone and overlying sandstone. Its short log shows, upwards, approximately 1.8 m of oil shale, a 0.2 m limestone band, another 0.6 m of oil shale, roughly 1.2 m of laminated carbonate with stromatolitic domes near the top, about 1.4 m of sandstone and a thin black-mudstone cap. These rounded figures are read from the published graphical scale. Ironstone nodules, soft-sediment deformation and small thrusts are also marked in the lower mudrocks. The accompanying description calls the main carbonate about 1 m thick: it is grey dolomitic limestone, weathering buff-yellow, with lamination and one bed that foundered into the underlying black mudstone. The upper domes are about 10–15 cm wide and 4 cm high.

The overlying fine-grained, pale grey to white, strongly cemented siliceous beds are assigned to the basal part of the informal Port Neuk Sandstone. Individual beds are 0.1–0.5 m thick, with sharp bases and sharp or upward-fining tops. Wave-ripple cross-lamination, generally symmetrical with slight asymmetry, has east–west-trending crests; synaeresis cracks on bed bases were interpreted as evidence of changing salinity. The log also marks muddy carbonate partings, a limestone clast derived from the same sedimentary succession near the sandstone base, and a mud-filled injection structure higher in the sandstone. These features suggest reworking along a shallow lake margin. This measured section is retained separately: the report’s grid reference differs from that of the teaching-guide outcrop, and its individual beds have not been matched securely to the photographs or older logs.

Pumpherston oil-shale and mudrock interval. Modern descriptions give about 25 m of dark shales and oil shales beneath the Bogwood interval. Cementstone and ironstone ribs interrupt the mudrocks, and phosphatic coprolites, fish remains and ostracods occur within them. Near the stream, resistant oil-shale seams form three prominent low reefs. The 1927 subdivisions total about 18 m, while the 1962 account describes 60 ft of shale above the marine band. These older measurements have not been matched to exactly the same boundaries as the modern 25 m account and are not combined into one thickness.

Pumpherston subdivisions: the 1927 descending log. Beneath the striped carbonate the original table records 5 ft of oil shale and shaly mudstone with two irregular calcareous ribs, each 9 in thick; 15 ft of mudstone and ribs; 14 ft of shaly mudstone with dark cementstone ribs; 8 ft of black mudstone and cementstone ribs; a 3 ft exposure gap at the stream mouth; 6 ft of good plain oil shale; and 8 ft of dark papery mudstone. The gap is missing exposure, not a demonstrated unconformity. “Plain” and “curly” describe oil-shale bedding in historical terminology; these labels do not establish equivalence with the named mine seams at Pumpherston village.

Naiadites–Euestheria horizon. A mudstone band approximately 8 m below the top of the modern 25 m interval contains Naiadites obesus and Euestheria sp. The former is a non-marine bivalve; the latter a clam shrimp, a branchiopod crustacean. Their occurrence in shales above the marine band is independently recorded in the 1962 memoir. This is a separate non-marine horizon rather than another name for the Pumpherston Shell Bed.

Pumpherston Shell Bed. Near the Long Rib stream, locally steep to vertical strata include approximately 0.5 m of soft dark fossiliferous mudstone above a thin limestone about 0.03 m thick. Fossils are commonly pyritised and the mudstone can develop yellow weathering deposits. The historical log recorded 1–1.5 ft of grey pyritous mudstone with marine shells. The bed records a marine incursion within the otherwise predominantly lake-and-delta succession.

Published marine fauna. The 1962 account of P. J. Brand’s South Queensferry collection lists Lingula sp., Euphemites sp., Aviculopecten subconoideus?, Edmondia?, Pernopecten sp., juvenile Pteronites sp., Sanguinolites clavatus, Schizodus cf. trigonalis, Streblochondria sp., Streblopteria? and orthocone nautiloid fragments. These are the published historical identifications, with their uncertainty qualifiers retained. They do not identify the uncaptained specimens in the gallery, and the publication year does not establish when Brand collected them. Regional ammonoids recorded from boreholes are not evidence of an ammonoid find on this shore.

Mudstone above the Queensferry Cements. About 1 m of dark mudstone separates the Pumpherston Shell Bed from the upper cementstone below. The 1927 log gives 4 ft of dark papery mudstone at this position.

Upper Queensferry Cement. This approximately 0.35 m carbonate bed is oolitic and weathers yellow. It is the upper of the two resistant cementstones forming the conspicuous Long Rib ridge. The 1927 section records 1 ft, while the 1962 account gives 1 ft 2 in.

Mudstone between the cements. Approximately 1 m of grey mudstone separates the upper and lower carbonate beds in the later accounts. The older log gives 2 ft. The interval should not be treated as a single named oil-shale seam simply because dark organic-rich sediment occurs nearby.

Lower Queensferry Cement. The later measured thickness is approximately 1.2 m. The bed is brown-grey, weathers yellow and has cavities that may contain bitumen. The older table described a cream-coloured carbonate with worm tubes and gave 5 ft. Both Queensferry Cements lie below the Pumpherston Shell Bed; neither is the true Burdiehouse Limestone at Port Neuk.

Lower Long Rib mudrocks and coprolite-bearing cementstone. Mudstones beneath the two cements contain further carbonate ribs and thin oil shales. The field guide describes a 0.15 m bedded cementstone forming a small overhang, with mudstone flakes and brown coprolites containing fish fragments. Contorted mudstone immediately above may record movement along bedding. This is a useful published observation, without an established match to every thin bed in the older table.

Lower-package subdivisions: the 1927 descending log. Below the lower Queensferry Cement the table records 15 ft of mudstone with thin cementstone ribs; 1–2 ft of No. 1 curly oil shale; 1 ft of shaly mudstone; 2 ft of mudstone; 1 ft 6 in of shaly mudstone; and a 3 in cementstone containing small mudstone chips. The 3 in bed and the later 0.15 m coprolite-bearing bed have not been demonstrated to be the same horizon.

Limits of the section and wider correlations. Farther towards Longcraig Pier, lower beds become obscured by shingle. The 1927 No. 2 oil shale was only tentatively correlated with the Dalmahoy Shale; it is useful context for the wider type shore, not an identified bed in every Long Rib photograph. Dunnet Shale and Barracks Ash west of the rail bridge, the Gullane Formation and large sills towards Whitehouse and Hound Point, and the separate inland boreholes and mine seams belong to wider accounts rather than this short traverse.

References
British Geological Survey, Lexicon entries for West Lothian Oil-Shale Formation, Calders Member, Hopetoun Member and Dunnet Sandstone.
Dean, M. T., Browne, M. A. E., Waters, C. N. and Powell, J. H. (2011). A lithostratigraphical framework for the Carboniferous successions of northern Great Britain (onshore), BGS RR/10/07, sections 4.3.13–4.3.13.2.
McAdam, A. D. South Queensferry Shore excursion, digital version of the Lothian geology field guide, localities 1–5.
Whyte, M. A. (2004). Queensferry Shore, in British Lower Carboniferous Stratigraphy, GCR 29, pp. 50–52.
Carruthers and colleagues (1927). The oil-shales of the Lothians, third edition, pp. 80–82 and 85–86.
Mitchell, G. H. and Mykura, W. (1962). The geology of the neighbourhood of Edinburgh, Queensferry Beds, Figure 15 and marine fauna, p. 102.
Robertson, T., Simpson, J. B. and Anderson, J. G. C. (1949). The limestones of Scotland, Burdiehouse Limestone at South Queensferry.
Loughlin, S. C. and Williamson, I. T. (2003). South Queensferry to Hound Point, GCR 27, white-trap account, pp. 188–190.
Maddox, S. J. and Andrews, J. E. (1987). Lithofacies and stratigraphy of a Dinantian non-marine dolostone from the Lower Oil-Shale Group of Fife and West Lothian, Scottish Journal of Geology 23, pp. 129–147.
Jones, N. S. (2007). The West Lothian Oil-Shale Formation: results of a sedimentological study, BGS IR/05/046, South Queensferry account and appendix log.
Wilkinson, M. (2008). South Queensferry Shore: a teacher’s guide, localities 7–10 and field map.