The Lower Jurassic of Europe: its subdivision and correlation

Page, Kevin

doi:10.34194/geusb.v1.4646

Cited by 125 publications

(120 citation statements)

References 56 publications

(93 reference statements)

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“…with their top being 'defined' by the base of the succeeding division of the same scale; see http://www.stratig raphy.org/index.php/ics-stratigraphicguide). Phelps (1985), realizing the distinction between French 'Horizons' and other high-resolution units equivalent to biohorizons, adopted the term 'zonule' to distinguish themthis distinction was maintained by some subsequent authors such as Page (1995Page ( , 2003. As pointed out by J.H.…”

Section: The 'French School': Horizons and 'Zonules'mentioning

confidence: 97%

From Oppel to Callomon (and beyond): building a high-resolution ammonite-based biochronology for the Jurassic System

Page

2017

LET

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By 1849, Alcide d'Orbigny had proposed a very modern looking global subdivision of a Jurassique ‘System’, into a sequence of 10 étages. D'Orbigny's stages were based on a basic biostratigraphical framework, but there were still a number of issues with its actual demonstrable applicability internationally. In 1856, Albert Oppel took d'Orbigny's framework and, as stated by W.J.Arkell in 1933, ‘breath[ed] new life into it…placing the whole science of stratigraphical geology on a new footing’. Oppel recognized eight ‘Etagen’, divided into a sequence of ‘zones’ which he considered to be time‐related to correlation units of theoretically universal application – a very clear and unambiguous statement of what now would be considered to be chronostratigraphical practice. Subsequently, evolution of Jurassic stratigraphy had, by the end of the 18th century led to S.S Buckman's high‐resolution ammonite correlation schemes using hemera – essentially the same as modern biohorizons. Although some of this detail was subsequently lost in his syntheses, from around 1933–1956, W.J. Arkell took many pre‐existing ‘zonal’ schemes and began to develop global ‘standard’ ammonite correlation schemes – again explicitly chronostratigraphical. Nevertheless, the potential for very high‐resolution ammonite‐based correlation schemes – with a resolution of only around 100,000 or less – was soon rediscovered and promoted by J.H. Callomon and by a very active ‘French School’. Despite all this activity, however, we still have not quite realized the ordered stratigraphical dreams of Oppel and his successors. Of the 11 stages now formally recognized within the Jurassic, four still do not have a ratified GSSP, and within the entire system, there still appear to be no formal agreements on what really are the ‘standard’ zones for each stage. Crucially, however, confusion is still widespread as to the ‘meaning’ of these zones – Jurassic ‘Standard Zones’ are chronozones not biozones – they have been explicitly so since Oppel's day, and as the stratigraphical building blocks of all ‘modern’ Jurassic stages, they must still be.

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Section: The 'French School': Horizons and 'Zonules'mentioning

confidence: 97%

From Oppel to Callomon (and beyond): building a high-resolution ammonite-based biochronology for the Jurassic System

Page

2017

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“…1), a fine-grained clayey carbonate sequence showing, in its medium and upper part, numerous intercalations of fine-to-medium grained siliciclastic beds, interpreted as turbidite deposits (Bodin et al 2016). The integration of biostratigraphic data from European basins led to the definition of three standard ammonite zonations (Subboreal, Tethyan and Mediteranean) and two standard calcareous nannofossil zonations for northwestern Europe and western Mediterranean countries (Cariou and Hantzpergue 1997, Bown and Cooper 1998, Mattioli and Erba 1999, Page 2003, Bilotta et al 2010, Gradstein et al 2012, Mattioli et al 2013, Fraguas et al 2015. The ammonite zonation of the Foum Tillicht section is based on the Mediterranean zonation, while the calcareous nanno-fossil zonation is based on the Tethyan zonation (Bodin et al 2016).…”

Section: Lithology and Biostratigraphy Of The Foum Tillicht Sectionmentioning

confidence: 99%

Orbital chronology of the Pliensbachian – Toarcian transition from the Central High Atlas Basin (Morocco)

Martínez¹,

Krencker²,

Mattioli³

et al. 2017

nos

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The Pliensbachian-Toarcian transition has been studied in depth for the major environmental changes and the marine invertebrate biodiversity crisis observed at that time. Despite a large number of studies performed, the time frames provided for this interval show large discrepancies from author to author. Major environmental changes occurring at that time impacted the sedimentation pattern and sedimentation rates, making uncertain the construction of time scales. Here, we provide a new astrochronological framework based on an expanded hemipelagic section from the Central High Atlas Basin (Morocco). δ 13 C and CaCO 3 measurements performed on the studied section allowed the construction of an orbital time scale based on the 405-kyr eccentricity and the obliquity cycles. This orbital time scale is then compared to the Peniche section (GSSP of the Toarcian Stage) in order to limit the effects of eventual condensation and erosion events on the construction of the orbital time scale. The duration of the early Toarcian Polymorphum Zone is then assessed at 0.9-1.0 myr, while the interval from the base of the Toarcian Stage to the FO of C. superbus is assessed at 0.51 myr. This long duration of the Polymorphum Zone highlights the fact that numerous sections in Europe are affected by long-term condensation and hiati around the Pliensbachian-Toarcian transition. Finally, we also explore the potential of the Central High Atlas basin to provide a refined time scale for the late Pliensbachian. Preliminary data lead to a duration assessment of the NJ5b calcareous nannofossil zone of at least 2.07 myr, and to a mean duration of the Emaciatum ammonite zone of 2.05 myr. These durations are ~1 myr longer than the durations proposed in the Geological Time Scale 2012, which illustrates the potential of the Central High Atlas Basin for calibrating the Pliensbachian times.

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“…This kind of characterization for the base of the Toarcian is mostly accepted by most students for Mediterranean province (Italy, Albania, Greece, southern Spain, North Africa, etc.) as well, where assemblages with Dactylioceratidae and Protogrammoceratinae are actually considered to be much more diverse compared with their English equivalents (Page 2003). However, in the Mediterranean areas, the distinction from late Pliensbachian faunas is generally less sharp and clear, chiefly because in these latter regions, members of the Liparoceratidae are very rare, and sometimes (for instance in the Apennine strata of Mount Serrone) they are found together with Eodactylites, as reported also by Guex (1973, pp.…”

Section: Stratigraphical Frameworkmentioning

confidence: 71%

Ammonite faunas, OAE and the Pliensbachian–Toarcian boundary (Early Jurassic) in the Apennines

Bilotta¹,

Venturi²,

Sassaroli³

2010

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The critical Jurassic event known as Early Toarcian Oceanic Anoxic Event (OAE) has been the subject of several studies, but its palaeontological characterization is still problematic, and its dating is therefore debated. The rich ammonite faunas of the Mediterranean Tethys (Italy, Greece, Albania, North Africa, southern Spain, etc.) demonstrate that the OAE separates two very different assemblages, resulting from a strong post-OAE biological renewal. Faunas before the anoxic event include many taxa already present in late Pliensbachian (evolute Phylloceratida; Reynesocoeloceratinae, Protogrammoceratinae and Arieticeratinae), whereas after the anoxic event new forms radiated (Nodicoeloceratinae, Harpoceratinae and Hildoceratinae; afterwards also groups as Mercaticeratinae, Phymatoceratidae and Hammatoceratidae). As these assemblages show remarkable differences from their Northwest European equivalents, in the Apennine it is necessary to use a Mediterranean zonation, here formally established. The examined data suggest accurate boundaries for the OAE, which separates our first two Toarcian Zones, corresponding to Tenuicostatum and Serpentinum standard chronozones. Within this context, the Apennine assemblage placed immediately below the anoxic event is an endemic fauna with more than 15 ammonite genera, two of which (Secchianoceras and Petranoceras) are exclusive of the interval in question. Most abundant are Phylloceratidae (Phylloceras, Lavizzaroceras, Calaiceras and Harpophylloceras), Juraphyllitidae (Meneghiniceras) and Lytoceratidae (Lytoceras); Dactylioceratidae (Dactylioceras, Eodactylites and Secchianoceras) and Hildoceratidae are comparatively less numerous, but these latter show the largest taxonomic diversity (Fontanelliceras, Trinacrioceras, Protogrammoceras, Petranoceras, etc.). The description of this fauna improves the knowledge of a poorly understood interval immediately preceding the OAE, thus allowing better correlations in the Mediterranean area. h Ammonites, chronostratigraphy, Early Jurassic, OAE, Tethys.Massimiliano Bilotta [dotpal@unipg.it],

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The Lower Jurassic of Europe: its subdivision and correlation

Cited by 125 publications

References 56 publications

From Oppel to Callomon (and beyond): building a high-resolution ammonite-based biochronology for the Jurassic System

From Oppel to Callomon (and beyond): building a high-resolution ammonite-based biochronology for the Jurassic System

Orbital chronology of the Pliensbachian – Toarcian transition from the Central High Atlas Basin (Morocco)

Ammonite faunas, OAE and the Pliensbachian–Toarcian boundary (Early Jurassic) in the Apennines

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