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A new ammonite from the Penarth Group, South Wales and the base of the Jurassic System in SW Britain

Published online by Cambridge University Press:  16 October 2020

Peter Hodges*
Affiliation:
Department of Geology (Palaeontology), Natural Sciences, National Museum of Wales, Cathays Park, CardiffCF1 3NP, UK
*
Author for correspondence: Peter Hodges, Email: [email protected]

Abstract

Two ammonites have been found in porcelaneous limestones of the White Lias Formation traditionally considered to be of Rhaetian (Late Triassic) age at Lavernock Point, south Wales (ST 181 681). These ammonites, named here Neophyllites lavernockensis. sp. nov, are the earliest recorded from the UK. This horizon is located directly above a major negative δ13C isotope anomaly (CIE1) in the Upper Cotham Member that marks the top of the Triassic System and below another negative δ13C isotope anomaly (CIE3). Both correlate with negative δ13C isotope anomalies in the Triassic–Jurassic global boundary stratotype section and point (GSSP) at Kuhjoch, Austria. This establishes the base of the tilmanni Chronozone, Hettangian Stage and Jurassic System in SW Britain within the White Lias Formation at Lavernock Point.

Type
Original Article
Copyright
© The Author(s), 2020. Published by Cambridge University Press

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References

Bloos, G (1999) Neophyllites (Ammonoidea, Psiloceratidae) in the earliest Jurassic of South Germany. Neues Jahrb. für Geologie Paläontologie, Abh. 211, 729.CrossRefGoogle Scholar
Donovan, DT, Curtis, MT and Curtis, SA (1989) A Psiloceratid Ammonite from the supposed Triassic Penarth Group of Avon, England. Paleontol. 32, 231–35.Google Scholar
Gallois, RW (2007) The stratigraphy of the Penarth Group (late Triassic) of the east Devon coast. Geoscience south-west Engl. 11, 287–97.Google Scholar
Gallois, RW (2009) The Lithostratigraphy of the Penarth Group (Late Triassic) of the Severn Estuary Area. Geoscience south-west Engl. 12, 7184.Google Scholar
Guex, J, Bartolini, A and Taylor, DG (2003) Discovery of Neophyllites (Ammonitina, Cephalopoda, Early Hettangian) in the New York Canyon sections (Gabbs Valley Range, Nevada) and discussion of the δ13C negative anomalies located around the Triassic-Jurassic boundary. Bull. Laboratoires Géologie, Minéralogie, Géophysique du Musée Géologique l’Université Lausanne 355, 247–55.Google Scholar
Hallam, A (1960) The White Lias of the Devon Coast. Proceedings Geologists’ Assoc. 71, 4760.CrossRefGoogle Scholar
Hesselbo, SP, Robinson, SA, Surlyk, F and Piasecki, S (2002) Terrestrial and marine extinction at the Triassic-Jurassic boundary synchronised with major carbon-cycle perturbation: a link to initiation of massive volcanism? Geol. 30, 251–54.2.0.CO;2>CrossRefGoogle Scholar
Hodges, P (1994) The base of the Jurassic System: new data on the first appearance of Psiloceras planorbis in southwest Britain. Geol. Mag. 131, 841–44.CrossRefGoogle Scholar
Hyatt, A (1867) The fossil cephalopods of the Museum of Comparative Zoology. Bull. Mus. Comparative Zool. 1, 71102.Google Scholar
Korte, C, Hesselbo, SP, Jenkyns, HC, Rickaby, REM and Spotl, C (2009) Palaeoenvironmental significance of carbon- and oxygen-isotope stratigraphy of marine Triassic–Jurassic boundary sections in SW Britain. J. Geol. Soc. London 166, 431–45.CrossRefGoogle Scholar
Korte, C, Ruhl, M, Pálfy, J, Ullmann, CV and Hesselbo, SP (2019) 10. Chemostratigraphy across the Triassic–Jurassic Boundary. In Chemostratigraphy Across Major Chronological Boundaries (eds Sial, AN, Gaucher, C, Ramkumar, M and Ferreira, VP), pp. 185210. John Wiley & Sons, Inc., New Jersey, USA, Geophysical Monograph no. 240.Google Scholar
Lange, W (1931) Die biostratigraphischen Zonen des Lias α und Vollraths petrographische Leithorizonte. Zentralbl. für Mineral. Geologie Paläontologie B, 349–72.Google Scholar
Lange, W (1941) Die Ammonitenfauna der Psiloceras-Stufe Norddeutschlands. Palaeontographica A 93, 1192.Google Scholar
Lindström, S, Pedersen, GK, van de Schootbrugge, B, Hansen, KH, Kuhlmann, N, Thein, J, Johansson, L, Petersen, HI, Alwmark, C, Dybkjaer, K, Weibel, R, Erlström, M, Nielsen, LH, Oschmann, W and Tegner, C (2015) Intense and widespread seismicity during the end-Triassic mass extinction due to the emplacement of a large igneous province. Geol. 43, 387–90.CrossRefGoogle Scholar
Lindström, S, van de Schootbrugge, B, Hansen, KH, Pedersen, GK, Alsen, P, Thibault, N, Dybkjaer, K, Bjerrum, C and Nielsen, LH (2017) A new correlation of Triassic-Jurassic boundary successions in NW Europe, Nevada and Peru, and the Central Atlantic Magmatic Province: A timeline for the end-Triassic mass extinction. Palaeogeogr. Palaeoclimatol. Palaeoecol. 478, 80142.CrossRefGoogle Scholar
Page, KN (2003) The Lower Jurassic of Europe; its subdivision and correlation. Geol. Surv. Den. Greenl. Bull. 1, 2359.Google Scholar
Page, KN and Bloos, G (1998) The base of the Jurassic System in West Somerset, south-west England – new observations on the succession of ammonite faunas of the lowest Hettangian Stage. Geoscience south-west Engl. 9, 231–35.Google Scholar
Pálfy, T, Demény, A, Haas, J, Carter, ES, Görög, A, Halász, D, Oravecz-Sheffer, A, Hetényi, M, Márton, E, Orchard, JM, Ozsvart, P, Vető, I and Zajon, N (2007) Triassic-Jurassic boundary events inferred from integrated stratigraphy of the Csővár section Hungary. Palaeogeogr. Palaeoeclimatology, Palaeoecol. 244, 133.Google Scholar
Pieńkowski, G, Niedźwiedzki, G and Wakśmundzka, M (2012) Sedimentological, palynological and geochemical studies of the terrestrial Triassic – Jurassic boundary in northwestern Poland. Geol. Mag. 149, 308–32.CrossRefGoogle Scholar
Ruhl, M, Kurschner, WM and Krystyn, L (2009) Triassic-Jurassic organic carbon isotope stratigraphy of key sections in the western Tethys realm (Austria). Earth Planet. Sci. Lett. 281, 169–87.CrossRefGoogle Scholar
Simms, MJ (2003) Uniquely extensive seismite from the latest Triassic of the United Kingdom; evidence for bolide impact? Geol. 31, 557–60.2.0.CO;2>CrossRefGoogle Scholar
Simms, MJ (2007) Uniquely extensive soft-sediment deformation in the Rhaetian of the UK; evidence for earthquake or impact? Palaeogeogr. Palaeoclimatol. Palaeoecol. 244, 407–23.CrossRefGoogle Scholar
Simms, MJ, Chidlaw, N, Morton, N and Page, KN (2004) British Lower Jurassic Stratigraphy. Joint Nature Conservation Committee, Peterborough, Geological Conservation Review Series no. 30, 458 pp.Google Scholar
Simms, MJ and Jeram, AJ (2007) Waterloo Bay, Larne, Northern Ireland: a candidate Global Stratotype Section and Point for the base of the Hettangian Stage and Jurassic System. ISJS Newsletter 34, 5068.Google Scholar
Suan, G, Föllmi, KB, Adatte, T, Bomou, B, Spangenberg, JE and van de Schootbrugge, B (2012) Major environmental change and bonebed genesis prior to the Triassic-Jurassic mass extinction. J. Geol. Soc. London 169, 191200.CrossRefGoogle Scholar
von Hillebrandt, A and Krystyn, L (2009) On the oldest Jurassic ammonites of Europe (Northern Calcareous Alps, Austria) and their global significance. Neues Jahrb. für Geologie Pälaontologie, Abh. 253, 163–95.CrossRefGoogle Scholar
von Hillebrandt, A, Krystyn, L and Kuerschner, WM (2007) A candidate GSSP for the base of the Jurassic in the Northern Calcareous Alps (Kuhjoch section, Karwendel Mountains, Tyrol, Austria). ISJS Newsletter 34, 220.Google Scholar
von Hillebrandt, A, Krystyn, L, Kuerschner, WM, Bonis, NR, Ruhl, M, Richoz, S, Schobben, MAN, Urlichs, M, Bown, PR, Kment, K, McRoberts, CA, Simms, M, Tomašových, A (2013) The global stratotype sections and point (GSSP) for the base of the Jurassic System at Kuhjoch (Karwendel Mountains, Northern Calcareous Alps, Tyrol, Austria). Episodes 36, 162–98.CrossRefGoogle Scholar
Warrington, G, Ivimey-Cook, HC and Cope, JCW (1994) St Audrie’s Bay, Somerset, England: a candidate Global Stratotype Section and Point for the base of the Jurassic system. Geol. Mag. 131, 191200.CrossRefGoogle Scholar
Warrington, G, Ivimey-Cook, HC and Cope, JCW (2008) The St Audrie’s Bay – Doniford Bay section, Somerset, England: updated proposal for a candidate Global Stratotype Section and Point for the base of the Hettangian Stage and of the Jurassic System. ISJS Newsletter 35, 166.Google Scholar
Waters, RA and Lawrence, DJD (1987) Geology of the South Wales Coalfield. Part III, The Country Around Cardiff. Third edition. Memoir for sheet 263 (England & Wales). London: HMSO, i–xi, 1–114.Google Scholar
Whittaker, A and Green, GW (1983) Geology of the Country around Weston-super-Mare. Memoirs of the Geological Survey of Great Britain, Nottingham. Sheet 279 with parts of 263 and 295, 147 pp.Google Scholar