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Our Work

Our work falls into the following:

1. The research of working groups to define the base of each of the Jurassic stages.
2. Working groups on other aspects of the Jurassic and informal groups
3. Facilitating communication on the Jurassic including organization of conference sessions, workshops and the international conference for ISJS that is held every 4 years to facilitate research on the Jurassic (see Meetings)
4. Supporting IGCP projects related to the Jurassic.
5. Improving resolution and correlation of the integrated stratigraphy for the Jurassic.
6. Furthering understanding of the Earth system during the Jurassic.
7. Providing an inclusive and diverse community that facilitates research aspirations at all career stages.

The next ISJS conference will be held in 2026. We organise a session at the International Stratigraphy Conference facilitated by ICS (STRATI). See (Meetings) for more information.

Research on the Jurassic by the executive of ISJS and voting members of the ISJS can be found under their individual webpages listed on the members page. The journal Volumina Jurassica is also a good place to find out who else is publishing research on the Jurassic.

Stage working groups and GSSPs

One of the major aims of the ISJS is to define all the Global Stratotypes, Sections and Points (GSSPs) for the Jurassic. Most of the research work is completed through working groups for each of the stages. This section summarises:

1. All the Jurassic boundaries that have been formally defined and ratified. Note that each of these boundaries have, firstly, been researched, defined and voted on by ISJS and the associated working group, secondly, received peer review and been voted on by the International Commission on Stratigraphy and, thirdly, received ratification by the International Union of Geological Sciences.
2. The status of the boundaries that are currently in progress.

• Tithonian – not yet formally defined
• Kimmeridgian
• Oxfordian – not yet formally defined
• Callovian – not yet formally defined
• Bathonian
• Bajocian
• Aalenian
• Toarcian
• Pleinsbachian
• Sinemurian
• Hettangian and base of the Jurassic

Tithonian

A working definition is near the base of the Hybonoticeras hybonotum ammonite zone and lowest occurrence of Gravesia genus, and the base of magnetic polarity chronozone M22An.

Possible candidates GSSPs considered so far are at Mt. Crussol or Canjuers (SE France), Fornazzo (Sicily, S. Italy) and sites in South America.

The convenor of the Tithonian Working Group is Ana Bertha Villaseñor. The secretary is Verónica Vennari.

Papers on sections that are also relevant include:

Gorodischi section, Ulianovsk area, Russia

• Rogov M.A. 2010. A precise ammonite biostratigraphy through the Kimmeridgian-Volgian boundary beds in the Gorodischi section (Middle Volga area, Russia), and the base of the Volgian Stage in its type area, Volumina Jurassica, Vol.VIII, p.103-130.
• Rogov M., Zakharov V. 2014. Russian GSSP Candidate Sections for the Jurassic System // STRATI 2013. First International Congress on Stratigraphy. At the Cutting Edge of Stratigraphy. Springer Geology, p.277-281, DOI 10.1007/978-3-319-04364-7_56.

Kimmeridge Bay, Dorset, UK

• Gallois, R. W. 2011. A revised description of the lithostratigraphy of the Kimmeridgian-Tithonian and Kimmeridgian-Volgian boundary beds at Kimmeridge, Dorset, UK, Geoscience in Southwest England, v12, p228-294.

Kimmeridgian

In January 2021, the proposal for the base Kimmeridgian GSSP received unanimous support from all the voting members of the International Commission on Stratigraphy. It was then recommended to the International Union of Geological Sciences Executive Committee who, in February 2021, also voted unanimously to ratify the proposal.

The Global Stratotype Section and Point (GSSP) for the base of the Kimmeridgian Stage (Upper Jurassic) is placed in the upper part of Bed 35 of the Staffin Shale Formation, 1.25 ± 0.01 m below the base of Bed 36 in block F6 in the foreshore at Flodigarry, Staffin Bay, Isle of Skye, Scotland. The coordinates for the middle part of the two adjacent sections (sections F6N and F6S) are 57° 39′ 39.5″ N, 6° 14′ 43.9″ W and 57° 39′ 40.5″ N, 6° 14′ 45″ W; UK National Grid Scheme NG 4687 7139 and NG 4687 7142 ± 5 m.

This proposed stratigraphic point coincides with the appearance over a short stratigraphic interval of several new ammonite taxa that delineate the base of the Subboreal ammonite Baylei Zone, the base of the Densicostata Subzone marked by the base of the flodigarriensis horizon, and, independently, the base of the Boreal ammonite Bauhini Zone. The main advantages of this locality are: the presence of a dual ammonite zonation marked by two extensively studied, well-preserved and very abundant groups of ammonites, and their preservation within a continuous section of ~120 m of open marine, fossiliferous, thermally immature mudrocks with no evidence of condensation or stratigraphic gaps. Dinoflagellate cysts, magnetostratigraphy and stable isotope data from the same section provide auxiliary markers. The thermal immaturity and unweathered nature of the strata in the Flodigarry section has permitted a direct Re-Os radiometric age of 154.1 ± 2.2 Ma to be obtained from the mudrocks 0.05 m below the proposed Kimmeridgian boundary. The corresponding stratigraphic level in the Submediterranean-Mediterranean successions is close to the boundary between the Hypselum and Bimammatum ammonite zones.

A full account is currently being prepared for publication in Episodes.

Any enquiries can be sent in the first instance to the ISJS chair Angela.Coe[AT]open.ac.uk

The convenor of the Kimmeridgian Working Group and lead author is Andrzej Wierzbowski, Faculty of Geology, University of Warsaw, Poland. awwierzb[AT]uw.edu.pl

Oxfordian

The working definition is at the base of the ammonite Cardioceras redcliffense Horizon at base of the Cardioceras scarburgense Subzone (Quenstedtoceras mariae Zone).

Candidates locations for the Global Stratotype Section and Point are at Thoux, Provence, SE France (Pellenard et al. (2014)) and Redcliff Point, Dorset, SW England (Melendez & Page (2015).

The co-chairs of the working group for definition of the base of the Oxfordian Stage are Kevin Page and Pierre Pellenard. The secretary is Ewa Głowniak.

Papers on sections that are also relevant include: Dubki section, Saratov area, Russia

• Kiselev, D., Rogov, M., Glinskokh, L., Guzhikov, A., Pimenov, M., Mikhailov, A., Dzyuba, O., Matveev, A., & Tesakova, E. (2013). Integrated stratigraphy of the reference sections for the Callovian-Oxfordian boundary in European Russia. Volumina Jurassica, 11(1), 59 - 96. Retrieved from https://vjs.pgi.gov.pl/article/view/26587

Callovian

The Callovian working group is currently being reformed. If you are interested in being a member please contact Angela Coe.

The working definition was the first occurrence of the ammonite genus Kepplerites (Kosmoceratidae) which marks the base of Macrocephalites herveyi Zone in sub-Boreal province of Great Britain to southwest Germany. The section at Albstadt-Pfeffingen in Germany has been intensively studied and has yielded much useful information on the ammonite faunas. However it has proved difficult, to date, to identify a section with this ammonite that is not condensed and fulfils some of the other GSSP criteria.

Recently, a well-exposed and expanded section with radio-isotopic dates has been identified in Argentina however here the endemism of the ammonites and possibly other fossil groups may be problematic, but this will be investigated by the new working group. New potential sections have also recently been identified in Kachchh, India.

Publications relevant to the Callovian have been posted on the Callovian working group website.

A report of progress of the Callovian working group was published in Volumina Jurassic: Mönnig (2014).

Other sections under consideration include: Prosek section, Nizhni Novgorod area, Russia

• Guzhikov, A.Ya., Pimenov, M.V., Malenkina, S.Yu., Manikin, A.G., Astarkin, S.V. 2010. Paleomagnetic, petromagnetic and terrigenous-mineralogical studies of Upper Bathonian-Lower Callovian sediments in the Prosek section, Nizhni Novgorod Region, Stratigraphy and Geological Correlation, v18, p42-62.
• Kiselev D.N. & Rogov, M.A. (2007): Stratigraphy of the Bathonian-Callovian boundary deposits in the Prosek section (Middle Volga region). Article 1. Ammonites and infrazonal biostratigraphy, Stratigraphy and Geological Correlation, v15, p485-515.

Bathonian

The Global boundary Stratotype Section and Point (GSSP) for the Bathonian is defined at the base of limestone bed RB071 in the Ravin du Bès Section, Bas-Auran area, southern Subalpine Chains, France (43° 57′ 38″ N 6° 18′ 55″ E). The base of the stage and Zigzag Zone corresponds to the first occurrence level of Gonolkites convergens Buckman and coincides with the first occurrence of Morphoceras parvum Wetzel.

Full details are published in Fernandez-Lopez, S.R. 2009. The Global Boundary Stratotype Section and Point (GSSP) for Base of the Bathonian Stage (Middle Jurassic), Ravin du Bes Section, SE France, Episodes, v. 32, p. 222-248.

Bajocian

The Global boundary Stratotype Section and Point (GSSP) for the Bajocian Stage, formally defined at the base of bed AB11 of the Murtinheira section at Cabo Mondego, Portugal (40° 11′ 57″ N 8° 54′ 15″ W)

The position of the boundary coincides with the first occurrence of the ammonite assemblage characterized by Hyperhoceras mundum and related species (H. furcatum, Bratinsina aspera, B. elegantula). The boundary lies just below the nanno-horizon of the entry of Waunaueria communis and W. fossacincta, and closely corresponds with a reversal to normal polarity. scale. An Auxiliary Stratotype Point (ASP) is also selected at the base of bed U10 of the Bearreraig Bay section on the Isle of Skye, Scotland, as the complementary referencefor the palaeobiological key of the Bajocian lower boundary, i.e. the evolutionary transition Graphoceras–Hyperhoceras.

Full details are published in G. Pavia and R. Enay. 1997. Definition of the Aalenian-Bajocian Stage boundary, Episodes v. 20, p. 16-22.

Aalenian

The Global Boundary Stratotype Section and Point (GSSP) for the Aalenian Stage is formally defined at the base of bed FZ107 in the Fuentelsaz section, Castilian Branch of the Iberian Range, Spain (41˚10′15″ N 1˚50′ 0″ W). The position of the boundary coincides with the first occurrence of the ammonite assemblage characterized by Leioceras opalinum and Leioceras lineatum and corresponds with a normal polarity interval.

A full account is published in Cresta et al. (2001) The Global Boundary Stratotype Section and Point (GSSP) of the Toarcian-Aalenian Boundary (Lower-Middle Jurassic), Episodes, v. 24, p. 166-175.

Toarcian

The Global Stratotype Section and Point (GSSP) for the base of Toarcian Stage is proposed at the base of limestone Bed 15e at Ponta do Trovão, in the Peniche section (39º22’15’’ N, 9º23’07’’ W) (Lusitanian Basin, Portugal) located 80 km north of Lisbon.

The base of the Toarcian Stage is marked by the FO of the ammonite Dactylioceras (Eodactylites) simplex. Co-occurring species, which help to define the lower part of the Polymorphum Zone in the absence of D. (E.) simplex, include D. (E.) pseudocommune and D. (E.) polymorphum. The ammonite association of D. (Eodactylites) ssp. and other species e.g. Protogrammoceras (Paltarpites) cf. paltum, Lioceratoides aff. balinense and Tiltoniceras aff. capillatum is particularly significant for the boundary definition.

The section at Almonacid de la Cuba (Iberian Range, Spain) provides complementary data of the ammonite succession in the Northwest European Hawskerense and Paltum Subzones and magnetostratigraphical data.

A full account is published in Bordalo da Rocha et al. 2016 Base of the Toarcian Stage of the Lower Jurassic defined by the Global Boundary Stratotype Section and Point (GSSP) at the Peniche section (Portugal), Episodes, v.39, p.460-481.

Pleinsbachian

The Global Boundary Stratotype Section and Point (GSSP) for the base of the Pliensbachian Stage (Lower Jurassic) is at the base of bed 73b of Hesselbo and Jenkyns (1995) in the Wine Haven section, Robin Hood’s Bay, Yorkshire, UK (54° 24′ 23.9″ N 0° 29′ 44.5″ W). This level contains the characteristic ammonite association Bifericeras donovani Dommergues and Meister and Apoderoceras sp.

A full account is published in Meister, C. et al. 2006. The Global Boundary Stratotype Section and Point (GSSP) for the Base of the Pliensbachian Stage (Lower Jurassic), Wine Haven, Yorkshire, UK. Episodes, v.29, p.93-106.

Sinemurian

The Global Stratotype Section and Point (GSSP) for the base of the Sinemurian, the second stage of the Lower Jurassic, is exposed in the cliff north of East Quantoxhead, about 6 km east of Watchet, Somerset, England (51° 11′ 27.7″ N 3° 14′ 11.6″ W). The boundary level is 0.90 m above the base of British Geological Survey Bed 145 of coinciding with the first appearance of the genera Vermiceras (V. quantoxense, V. palmeri) and Metophioceras (M. sp. indet. 1).

A full account is published in Bloos, G and Page K.N. 2002. Global Stratotype Section and Point for base of the Sinemurian Stage (Lower Jurassic). Episodes v.25, p.22-28.

Hettangian and base of the Jurassic

The Global Stratotype Section and Point (GSSP) defining the base of the Jurassic System, Lower Jurassic Epoch, and Hettangian Stage is situated at the Kuhjoch pass, Karwendel Mountains, Northern Calcareous Alps, Austria (47°29’02″N/11°31’50″E). The Triassic-Jurassic (T-J) boundary is exposed at Kuhjoch West and at Kuhjoch East, and corresponds to the first occurrence of the ammonite Psiloceras spelae tirolicum.

A full account is published in:

Von Hillebrandt, A. et al. 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 v.36. p.162-198.

Other working groups

High-resolution Jurassic Stratigraphy

(more info to come)

Informal groups

North Africa Jurassic

Convenor: Abbas Marok. Aims are to propose some Jurassic geosites of international interest and raise the profile of work on the Jurassic in Africa. Please get in touch with Abbas Marok if you are interested.