Foraminifera of the Gault Clay Formation: An update
Introduction
The Gault Clay Formation is a distinctive blue-grey mudstone that forms an important component of the mid-Cretaceous succession of the United Kingdom. Towards the South-West of England it passes laterally into the Upper Greensand Formation (Jukes-Browne and Hill, 1900; Drummond, 1970; Simmons et al., 1991; Gallois and Owen, 2019 and references therein) while northwards there is a transition into the Red Chalk of Norfolk, Lincolnshire and Yorkshire (Burrows et al., 1890; Gallois and Morter, 1982; Mitchell, 1995; Owen, 1995).
In East Anglia, Gallois and Morter (1982) identified 19 beds (numbered G1–G19). These beds appeared to record small-scale rhythms (ca. 1–2 m thick), often with a phosphate-rich, nodular, basal bed. These rhythms are more weakly developed in the Upper Gault Clay, as compared to the Lower Gault Clay. This scheme was rationalized by Gallois et al. (2016) with beds G1–G19 placed within seven distinctive sedimentary units (GE 1–7). How these two schemes relate to the initial bed numbers of the Gault Clay Formation is shown in Gallois et al. (2016, fig. 5) which shows how the various numbering schemes can be correlated across East Anglia and S.E. England (Weald and Folkestone).
The Gault Clay Formation is best known for its molluscan fauna (Casey in Smart et al., 1966; Morter and Wood, 1983) with ammonites providing both a viable and detailed biostratigraphy (Spath, 1923–1943Spath, 1923Spath, 1923–1943; Casey, 1954a, Casey, 1954b, 1957, 1961, 1965; Owen, 1958, 1963, 1971a, 1971b, 1972, 1976, 1984). The earliest work on the Gault Clay Formation concentrated on the ‘type locality’ of Copt Point, Folkestone, where De Rance (1868); Price (1874a, b, 1876, 1879) and Jukes-Browne and Hill (1900) established the lithological succession of beds, numbered l–Xlll, although initially it was only sub-divided into Beds l–Xl: see Hart and Fox (2020) for a recent account of the history of the Copt Point investigations. It was realised, in the 1970s, that there were problems with the interpretation of the Copt Point succession, especially in the upper levels with landslides and solifluction having ‘moved’ parts of the overlying Glauconitic Marl and, in places, this had become confused with the glauconite-rich mudstones of Bed Xll. This resulted in an error that created a mistaken view of the Bed Xl – Bed Xll – Bed Xlll interval as well as the relationships across the Bed Xlll – Glauconitic Marl boundary (Hart, 1973a,b). This confusion was resolved during construction of the Channel Tunnel both in the 1970s and, subsequently, in the main construction phase (1988–1991): see Carter and Hart (1977); Hart (1993, 2000) and Harris et al. (1996). This history has been described by Hart and Fox (2020, Fig. 2) insofar as it impacted on the interpretation of both the hiatus at the base of the Cambridge Greensand and the overall interpretation of the Copt Point succession.
Section snippets
Foraminifera of the Gault Clay Formation
The foraminifera of the Gault Clay Formation are abundant, diverse and generally well-preserved. Chapman’s classic work on the ‘Foraminifera of the Gault of Folkestone’ (Chapman, 1891–1898) was based, almost exclusively, on samples from Copt Point, using Beds l–Xlll and measured distances within each unit. There is some confusion that the nomenclature change, from using Beds l–Xl to Beds l–Xlll, occurred during his work and the new additions were not sampled to the same degree as the lower
Investigated successions of the Gault Clay Formation
In South-East England there are numerous locations where the Gault Clay Formation can be sampled for micropalaeontological research (Fig. 1). Extending from Copt Point, near Folkestone, the outcrop includes locations in the South Downs (e.g., Eastbourne), the North Downs (e.g., Sevenoaks), the Isle of Wight (both Culver Cliff and Compton Bay), and the Chilterns (e.g., Mundays Hill Quarry). Added to the exposures on the coast and in working (or disused) quarries are the numerous boreholes (e.g.,
Foraminiferal zonation
The first meaningful attempt at a zonation of the Gault Clay Formation in the twentieth century was by Carter in Bruckshaw et al. (1961) in which the distribution of key foraminifera in the Albian – Turonian interval was presented (Fig. 2). When this preliminary zonation was published none of the taxa (listed as 1–45) were identified; the figure was published without a full caption! Indeed, even in the more complete Channel Tunnel Investigation by D.J. Carter in 1964–1966, many of the taxa were
Distribution of aragonitic foraminifera
One of the important groups of foraminifera recorded in the Gault Clay Formation are the members of the Superfamily Robertinacea (Loeblich and Tappan, 1964). These genera and species are now represented by the Ceratobuliminidea Cushman, 1927 following Loeblich and Tappan (1987). The Lower Cretaceous members of this superfamily were described by Hart (1984), especially those recorded from the Gault Clay Formation. The following species are recorded:
Conorboides lamplughi (Sherlock, 1914);
Palaeoecology and palaeogeography
If the distribution of aragonitic foraminifera is a primary, palaeoecological signal, what other changes in the assemblage provides supporting evidence? Agglutinated taxa are very much more abundant after the Cristatum Zone and this is true at Folkestone (Fig. 3), Munday’s Hill Quarry (Fogerty et al., 2019, Fig. 4) and in the Glyndebourne borehole (Fig. 4). Species such as Arenobulimina, Marssonella, Tritaxia and Cribrostomoides all require clastic material with which to construct their tests
Summary
The distribution of foraminifera in the Gault Clay Formation is shown to provide a viable tool for regional correlation. Many of the significant changes in the assemblage are shown to coincide with known hiatuses in the ammonite succession and the presence of phosphate concentrations. The Lower Gault Clay, in the mudstone facies, is always characterized by the presence of aragonitic foraminifera, often showing exquisite preservation. Of particular interest is the presence of comparable
Acknowledgements
TF acknowledges the help provided by Gary McNeely and Aggregate Industries in providing access to Munday’s Hill Quarry. Dr Steve Stukins and Dr Haydon Bailey facilitated the microscope work undertaken by TF at the Natural History Museum (London). Mr Tim Absalom (University of Plymouth) is thanked for providing the final versions of the figures. This research did not receive any specific grants from funding agencies in the public, commercial or not-for-profit sectors.
References (135)
The Mid-Dorset Swell. Evidence of Albian–Cenomanian movements in Wessex
Proceedings of the Geologists’ Association
(1970)Sedimentology and palaeoenvironment of the Shenley Limestone (Albian, Lower Cretaceous); an unusual shallow-water carbonate
Proceedings of the Geologists ‘Association
(1992)Middle Albian geography, oceanography and climate and the setting of the Kirchrode l and ll borehole sites
Palaeogeography, Palaeoclimatology, Palaeoecology
(2001)Kirchrode l and ll boreholes: technical details and evidence on tectonics, and palaeoceanographic development during the Albian
Palaeogeography, Palaeoclimatology, Palaeoecology
(2001)Palaeoceanographic and climate changes during the Albian, summary of the results from the Kirchrode boreholes
Palaeogeography, Palaeoclimatology, Palaeoecology
(2001)- et al.
The stratigraphy of the Gault of East Anglia
Proceedings of the Geologists’ Association
(1982) - et al.
The stratigraphy of the Gault Formation (Early Cretaceous, Albian) in East Anglia and south-east England
Proceedings of the Geologists’ Association
(2016) Foraminifera, sequence stratigraphy and regional correlation; an example from the uppermost Albian of Southern England
Revue de Micropaléontologie
(2000)- et al.
Atlantic paleobathymetry, paleoproductivity and paleocirculation in the late Albian: the benthic foraminiferal record
Palaeogeography, Palaeoclimatology, Palaeoecology
(2001) Découverte de Planomalina buxforfi (GANDOLFI) et d’autres foraminifères planctoniques inattendus dans l’Albien Supérieur d’Abbots Cliff (Kent, Angleterre): consequences paléogeographique et biostratigraphiques
Geobios
(1981)
Essai de corréllation des zones de foraminifères de l’Albien stratotypique (Aube, France) avec les zones d’ammonites
Geobios
Some Mesozoic adherent foraminifera
Palaeontology
Polymorphinidae from the Upper Cretaceous of England
Palaeontology
The morphology and development of species of Marssonella and Pseudotextulariella from the Chalk of England
Palaeontology
Arenaceous Foraminifera from the Upper Cretaceous of England
Quarterly Journal of the Geological Society, London
The Ataxophragmiidae of England: Part 1, Albian-Cenomanian Arenobulimina and Crenaverneuilina
Revista Española de Micropaleontologia
Taxonomische Bemerkungen zu den Ammobaculites, Haplohphragmium, Lituola und verwandten Gattungen
Senckenbergiana
Revision von Berthelin’s Mémoire 1880 über die Alb-Foraminiferen von Montcley
Senckenbergiana Lethaea
Feinstratigraphisch wichtige Ostracoden aus dem nordwestdeutschen Valendis
Paläontologische Zeitschrift
Taxinomische Revision und Nomenklatur zu Franz E. Hecht ‘Standard-Gliederung der nordwestdeutschen Unterkreide nach Foraminiferen’ (1938)
Senckenbergiana Lethaea, Frankfurt
New genera of Foraminifera from the Lower Cretaceous of Germany and England
Journal of Paleontology
Mikropaläontologische Untersuchungen zur Stratigraphie des nordwest-deutschen Valendis
Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft
Marine Unterkreide (Boreal und Tethys)
Die Foraminiferen der Unterkreide von Trinidad, B. W. I. Erster Teil: Cucheund und Toco Formation
Eclogae Geologicae Helvetiae
Die Foraminiferen der Unterkreide von Trinidad, B. W. I.: Maridale Formation (Typlokalitat)
Eclogae Geologicae Helvetiae
Mémoire sur les Foraminifères de l’Étage Albien de Montcley (Doubs)
Mémoire de la Société géologique de France, Paris
Foraminiferen aus dem Senon Palastinas
Zeitschrift des Deutschen Palästina-Vereins
Die Foraminiferengattung Gavelinella nov. gen. und die Systematik des Rotaliiformes
Sveriges Geologiska Undersökning
The work of the Channel Study Group, 1958–60
Proceedings of the Institution of Civil Engineers
Mid-Cretaceous palaeontology and stratigraphy, Central North Sea
The foraminifera of the Red Chalk of Yorkshire, Norfolk and Lincolnshire
Journal of the Royal Microscopical Society, London
Aspects of mid-Cretaceous stratigraphical micropalaeontology
Bulletin of the British Museum, Natural History (Geology)
Falciferella, a new genus of Gault Ammonites, with a review of the family Aconeceratidae in the British Cretaceous
Proceedings of the Geologists’ Association
New genera and subgenera of Lower Cretaceous ammonites
Journal of the Washington Academy of Sciences
The Cretaceous Ammonite genus Leymeriella, with a systematic account of its British occurrences
Palaeontology
The stratigraphical palaeontology of the Lower Greensand
Palaeontology
A monograph of the Ammonoidea of the Lower Greensand
Palaeontology of the Gault
The lithostratigraphy and biostratigraphy (Foraminifera) of the Early Cretaceous of the Southern North Sea Basin
An outline of a re-classification of the foraminifera
Contributions from the Cushman Laboratory for Foraminiferal Research 3
On foraminifera of the Netherlands No. 9. Sur quelques espèces nouvelles ou peu connues dans le Crétacé Inférieur (Albien) des Pays-Bas
Geologie Mijnbouw, n.s
Foraminifera from the Middle Neocomian of the Netherlands
Journal of Paleontology
Les espèces du genre Epistomina Terquem, 1883
Revue de l’Institut Français du Pétrole, Paris, n.s.
Les Foraminifères de l’Albien des Pays-Bas
Memoires de la Société Géologique de France, Paris, n.s.
On the Albian or Gault of Folkestone
Geological Magazine
Foraminiferen und Ostrakoden aus dem Kreidemergeln der oberbayerischen Alpen
Abhandlungen, Bayerische Akademie der Wissenschaften, Munich
Die Foraminiferen der Unterkreide. 1 Folge. Foraminiferen aus dem Albien von Weden am Mittellandkanal
Jahresbericht der Neidersächsiche Geologische Verein
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First occurrence of azhdarchoid pterosaurs in the Gault Formation (Lower Cretaceous, Albian) of England, United Kingdom with a brief review of Gault pterosaurs
2022, Proceedings of the Geologists' AssociationCitation Excerpt :In Kent and East Sussex, the Gault Formation is divided into the upper and lower Gault formations (Gale and Owen, 2010). The age of the Gault Formation is well defined as middle-late Albian based upon distinctive ammonite and foraminifera assemblages (Gale and Owen, 2010; Hart et al., 2020; Hart and Fox, 2021 and references therein). In Hertfordshire and Cambridgeshire, the Gault Formation is overlain unconformably by the Cambridge Greensand Member of the Westbury Marly Chalk Formation, a deposit rich in phosphatic clasts and vertebrate remains derived from the underlying Upper Gault Formation (Unwin, 2001; Smith et al., 2020 and references therein).
The mid-Cretaceous debate: Evidence from the foraminifera
2021, Cretaceous ResearchCitation Excerpt :Smaller benthic foraminifera (SBF) are abundant and diverse in almost all the shelf successions in the Mesozoic. In the Gault Clay Formation, for example, there are more than 100 species present in a typical, processed, micropalaeontological sample (Berthelin, 1880; Chapman, 1891–1898; Magniez-Jannin, 1975; Carter and Hart, 1977; Harris, 1982; Hart et al., 1989; Fogerty et al., 2019; Hart et al., 2020b). In the following discussion, the SBF of the Triassic to end-Cretaceous are considered and the major turnovers identified, one of which is clearly pertinent to the Middle Cretaceous debate.