callovian

CALLOVIAN WORKING GROUP

OF THE INTERNATIONAL SUBCOMMISSION ON JURASSIC STRATIGRAPHY

I. News II. Current researches III. References IV. Callovian WG reports V. Callovian WG members VI.Contacts & links

I. News

14.10.2024 - new publications added:

Seyed-Emami K., Raoufian A., Mönnig E. (2015) Macrocephalitinae (Ammonoidea, Middle Jurassic) from North and Central Iran // Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen. Bd. 278. P.257-279. pdf

Silva R.L., Alsen P. (2024) Stable carbon isotope chemostratigraphy of the base of the Callovian in Greenland // Gondwana Research. Vol. 136. P. 84-91. pdf

06.08.2024 - new publications added:

Bitterli-Dreher P. (2020) Geologie und Paläontologie des Bergwerks Herznach. Teil 1: Die Erdgeschichte des «Meeresbodens» // Schweizer Strahler. Nr.2. S.22-31. pdf

Bitterli-Dreher P. (2021) Geologie und Paläontologie des Bergwerks Herznach. Teil 2: Die Erdgeschichte des Eisenerzes // Schweizer Strahler. Nr.4. S.22-33. pdf

Bitterli-Dreher P. (2023) Ein seltener Ammonit im Jurameer Mitteleuropas: Clydoniceras discus var. hochstetteri, Sow. 1813 // Schweizer Strahler. Nr.1. S.17-22. pdf

Grant-Mackie J.A., Francis G., Westermann G.E.G., Challinor A.B. (2006) Jurassic molluscan palaeontology of the Telefomin area, Papua New Guinea // Geological Survey of Papua New Guinea, Memoir, Vol. 18. P. 1–102. pdf

Galácz A., Földvári G. (2024) Heteromorph ammonite Parapatoceras from the Lower Callovian of Villány, South Hungary // Földtani Közlöny, Vol. 154. no. 1. P.59-63. pdf

Jain S. (2024) Note on the earliest records of genus Macrocephalites Zittel: implications for biostratigraphic correlations // Historical Biology, DOI 10.1080/08912963.2024.2345223 pdf

Mahboubi C.Y., Jain S., Naimi M.N. (2024) First record of the heteromorph ammonite genus Parapatoceras Spath, 1924 from the lower Callovian (Middle Jurassic) of Algeria // Neues Jahrbuch für Geologie und Paläontologie – Abhandlungen. Vol. 310. no. 3. P. 293-300. DOI: 10.1127/njgpa/2024/1184 pdf

Thierry J. (2003) Les ammonites du Bathonien-Callovien du Boulonnais: biodiversité, biostratigraphie et biogéographie // Geobios, Vol. 36. no.1. P.93-126. pdf

24.12.2023 - new publications added:

Gulyaev D.B., Ippolitov A.P. (2023) Macrocephalites aff. triangularis Spath (Macrocephalitidae, Ammonitida) from the middle Bathonian of Eastern Crimea // Jurassic System of Russia: Problems of stratigraphy and рalaeogeography. Proceedings of the IXth All-Russian Meeting with international participation. Syktyvkar, September 9–16, 2023. Syktyvkar: IG Komi SC UB RAS. P. 45-50. pdf

Gulyaev D.B., Ippolitov A.P., Desai B.G. (2023) Stratigraphy and ammonites of the Middle Jurassic of the Yanyshar Ridges (Eastern Crimea). Preliminary results // Jurassic System of Russia: Problems of stratigraphy and рalaeogeography. Proceedings of the IXth All-Russian Meeting with international participation. Syktyvkar, September 9–16, 2023. Syktyvkar: IG Komi SC UB RAS. P. 51-62. pdf

Dietze V., Franz M. (2023) Nachtrag zur Ammonitenfauna im Grenzbereich Bathonium/Callovium (Mittlerer Jura) in Eningen unter Achalm (Mittlere Schwäbische Alb, SW-Deutschland), der Typuslokalität der Ammonitenart Kepplerites keppleri (Oppel, 1862) // Jh. Ges. Naturkde. Württemberg. Bd.179. S. 173–184. DOI: https://doi.org/10.26251/jhgfn.179.2023.173-184 pdf

Kamo S.L., Riccardi A.C. (2009) A new U–Pb zircon age for an ash layer at the Bathonian–Callovian boundary, Argentina // GFF, Vol. 131. no.1-2, P.177-182. pdf

Kapilima S. (1984) Stratigraphische und paläontologische Untersuchungen im Jura und der Kreide des tansanischen Küstenstreifens im Hinterland von Dar-Es-Salaam und Bagamoyo // Berliner geowissenschaftliche Abhandlungen. Reihe A, Geologie und Paläontologie. Bd. 57, 77 S., DOI: https://doi.org/10.23689/fidgeo-5408 pdf

28.01.2022 - new publication added:

Mönnig E., Dietl G. (2022) Die Ammoniten-Gattung Kepplerites in der obersten Herveyi- und der Koenigi-Zone (Unter-Callovium, Mittel-Jura) von Nord- und Süddeutschland // Geologie und Paläontologie in Westfalen. Bd. 95. S. 3-84. pdf

09.12.2022 - new publications added:

Galácz A. (2022) Occurrence of the peculiar ammonites Phlycticeras and Oecoptychius in the Callovian (Middle Jurassic) of the Villány Hills (South Hungary) // Geologica Balcanica. Vol. 51. no. 3. P. 51–56. pdf

Kiselev D.N. (2022) Ammonites and infrazonal stratigraphy of the boreal and subboreal Bathonian and Callovian // Transactions of the Geological Institute. Vol. 628. 667 p. [in Russian] pdf

Martin A., Mangold Ch. (2015) Le genre Bullatimorphites du Bathonien moyen et supérieur du Mâconnais (Saône-et Loire, France) // Strata, série 2, Vol. 52, 119 p. pdf

31.12.2021 - new publication added:

Gulyaev D.B., Ippolitov A.P. (2021) Lower Callovian of Kanev dislocations, Cherkasy oblast, Ukraine: ammonites and stratigraphy // Stratigraphy and Geological Correlation. Vol. 29. No. 7. P. 767–847. pdf

30.10.2021 - new publications added:

Dietl G., Mönnig E., Schweigert G. (2021) The ammonites of the keppleri Horizon (basal Callovian, Middle Jurassic) of Albstadt-Pfeffingen (Swabian Alb, Germany)–biostratigraphy and correlation // Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen, Bd. 302. Hft.1. P. 1-33.

Fatmi A.N. (1969) Lower Callovian ammonites from Wam Tangi, Nakus, Baluchistan. Memoirs of the Geological Survey of Pakistan // Palaeontologia Pakistanica, Vol. 8, 14 p. pdf

Gulyaev D.B., Ippolitov A.P., Zaitsev B.A. (2021) New data on the lower Callovian Boreal ammonites of Crimea // Contributions to current cephalopod research: Morphology, Systematics, Evolution, Ecology and Biostratygraphy. Proceeding of conference (Moscow, 25 – 27 October, 2021); Russian Academy of Sciences, Borissiak Paleontological Institute; eds. T.B. Leonova, V.V. Mitta. P.39-42. pdf

31.12.2020 - new publication added:

Alsen P., Hovikoski J., Svennevig K. (2020) Middle Jurassic sandstone deposition in the Wandel Sea Basin: evidence from cardioceratid and kosmoceratid ammonites in the Mågensfjeld Formation in Kilen, North Greenland // GEUS Bulletin, Vol. 44. DOI 10.34194/geusb.v44.5342 pdf

Jain S. (2020) Immigration of the genus Macrocephalites Spath and the Bathonian biostratigraphy of the Kachchh basin (Western India, South Tethys) // Zitteliana. Bd.94. P.3-36. pdf

Parent H., Garrido A.C., Brambilla L., Alberti M. (2020) Upper Bathonian ammonites from Chacay Melehué (Neuquén Basin, Argentina) and the chronostratigraphy of the Steinmanni Zone // Boletín del Instituto de Fisiografía y Geología, Vol. 90. P. 1-37. pdf

01.09.2020 - new publication added:

Nakada K., Nakayama K., Sakai Y., Noda Y. (2019) Middle Jurassic fossil molluscan assemblage from the Itoshiro River in Kaizara, Ono City, Fukui Prefecture // Mem. Fukui Pref. Dinosaur Mus. Vol.18. P.31‒42. pdf

24.02.2020 - new publications are added:

Metodiev, L., Sapunov, I. (2019) Studia breviora: On the "Macrocephalites macrocephalus" Zone of the lower Callovian in NW Bulgaria // Geologica Balcanica. Vol. 48. no. 3. P. 43–47. pdf

Mihajlović, M. (1954) Description stratigraphique et paleontologique de quelques especes d'Ammonites des couches de Klauss de Greben (Serbie orientale) // Annales géologiques de la Peninsule balkanique, T.22. P.123-134. pdf

11.05.2019 - new publications are added:

Jain S. (2019) On the occurrence of the Indonesian ammonite Macrocephalites keeuwensis Boehm [M & m] from Kachchh (Western India) // Zitteliana. Bd. 93. P.3-24. pdf

Metodiev L. (2019) Rare and little-known ammonites from the Lower and Middle Jurassic of the Western and Central Balkan Mts (Bulgaria) // Geologica Balcanica. Vol. 48. no.1. P. 3–41. pdf

27.08.2018 - new publications are added:

Majidifard M.R. (2018) Callovian ammonites from northern Iran // Revista Brasileira de Paleontologia, 21(1):17–46. doi:10.4072/rbp.2018.1.02 pdf

Mangold C., Martin A., Prieur A, (2012) Les Périsphinctidés du Bathonien moyen et supérieur du Mâconnais (Saône-et-Loire, France) // Docum. Lab. Géol. Lyon, no. 169, 155 p. pdf

Jain S. (2017) Occurrences, age and paleobiogeography of rare genera Phlycticeras and Pachyerymnoceras from South Tethys // Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen, V. 283. no.2. P.119-149. pdf

27.12.2017 - new publications devoted to Bt/Cl boundary of Hungary, Bulgaria, Northern Caucasus, France and proposed GSSP (as well as Kepplerites) were added:

Galácz A. (1980) Bajocian and Bathonian ammonites of Gyenespuszta Bakony Mts., Hungary // Geol. Hung. Ser. Paleont. Fasc. 39. 227 p. pdf

Majidifard M.R. (2018) Callovian ammonites from northern Iran // Revista Brasileira de Paleontologia, 21(1):17–46. doi:10.4072/rbp.2018.1.02 pdf

Loczy L. (1915) Monographie der Villanyer Callovien-Ammoniten // Geol. Hung. T.1. Fasc. 3-4. S. 255-502. pdf

Mangold C. (1970) Stratigraphie des etages Bathonien et Callovien du Jura meridional // Doc. Labor. Géol. Fac. Sci. Lyon. no. 41. Fasc. 2. 246 p. pdf

Metodiev L., Sapunov I. (2017) The ammonite zones of the Bathonian in Bulgaria // Geologica Balcanica. Vol. 46. no. 2. P. 57–63. pdf

Mönnig E., Dietl G. (2017) The systematics of the ammonite genus Kepplerites (upper Bathonian and basal Callovian, Middle Jurassic) and the proposed basal boundary stratotype (GSSP) of the Callovian Stage // N. Jb. Geol. Paläont. Abh. Vol. 286. no.3. P. 235-287. DOI 10.1127/njgpa/2017/0697

Tsereteli I.D. (1968) Bathonian ammonites of the Georgia. Tbilisi: Metsniereba. 98 p. [in Russian] pdf

Tsereteli I.D. (1989) Bathonian oppeliids of Transcaucasus. Tbilisi: Metsniereba. 112 p. [in Russian] pdf

05.10.2017 - new publication devoted to Bt/Cl boundary of Iran was added:

Seyed-Emami K., Raoufian A. (2017) Ammonites from Bathonian and Callovian (Middle Jurassic) North of Damghan, Eastern Alborz, North Iran // Zitteliana. Bd. 89. P. 253-269. pdf

10.07.2017 - new publication devoted to Bt/Cl boundary of Iran was added:

Zadesmaeil M., Majidifard M.R., Vaziri S.H., Jahani D. (2017) Reineckeiidae (Ammonoidea) Family of the Dalichai Formation in Damghan Area (East Alborz), Iran // Open Journal of Geology, Vol.7, P.888-914. DOI: 10.4236/ojg.2017.76061 pdf

19.05.2017 - new publication devoted to Bt/Cl boundary was added:

Mönnig E. (2017) The evolution of Oppel’s ‘Macrocephalusbett’ (Callovian, Middle Jurassic). Lethaia, https://doi.org/10.1111/let.12220

19.04.2017 - new publications devoted to Bt/Cl boundary of India are added:

Jain S. (2017) Occurrences, age and paleobiogeography of rare genera Phlycticeras and Pachyerymnoceras from South Tethys // Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, Vol. 283, no.2, P.119-149.

Sharma J.K., Pandey D.K. (2016) Taxonomy of Late Bathonian-Oxfordian ammonites from the Jaisalmer basin: Implications for intrabasinal litho- and biostratigraphic correlations // Journal of the Palaeontological Society of India. Vol.61. no.2. P.249-266. pdf

08.09.2016 - new publications devoted to Bt/Cl boundary of Iran are added:

Dabbaghi Sadr F., Seyed-Emami K., Majidifard M. (2012) Biostratigraphy and Lithostratigraphy of the Middle and Late Jurassic Rocks West of Binalud Range Northwest of Neyshabour, Northeast Iran // Geosciences. Scientific Quarterly Journal. Vol. 22. no.85. P.35-47. [in Persian] pdf

Faridani M, Raisossadat S N, Majidifard M, BaBazadeh S A. (2013) Effects of sea level fluctuations on distribution and diversity of ammonites in the middle and upper Jurassic strata northwest of Neyshabur // Journal of Stratigraphy and Sedimentology Researches. Vol.28. no.4. P.81-94. [in Persian] pdf

Paknia M., Alimohammadian H., Majidifard M.R., Sabouri J., Aghanabat A. (2013) Magnetostratigraphy of Bathonian-Callovian Boundary (Middle Jurassic) of Golbini Section, Eastern Alborz, Iran // Geosciences. Scientific Quarterly Journal. Vol. 22. no.88. P.19-31. [in Persian] pdf

Sarbandi Farahani T., Majidifard M., Kebriaee-Zadeh M.R., Mohammadi M. (2015) Study of the Lithostratigraphy and Biostratigraphy of Ammonite Fauna of the Dalichai Formation at the Mahdishahr Section, N Semnan // Geosciences. Scientific Quarterly Journal. Vol. 24. no.94. P.27-39. [in Persian] pdf

30.06.2016 - new publications are added:

Böckh J. (1881) Adatok a Mecsekhegység és dombvidéke jurakorbeli lerakódásainak ismeretéhez. II. Palaeontologiai rész // Értekezések a Természettudományok Köréből 11/9, P.1–106. pdf

Galácz A. (2015) Macrocephalitid-bearing Lower Callovian (Middle Jurassic) beds in the Mecsek Mts (South Hungary) // Hantkeniana. Vol. 10, P.73–88. pdf

Gulyaev D.B., Ippolitov A.P. (2016) On the Bathonian-Callovian boundary deposits in the reference sections of the north of European Russia (Komi Republic) // Golden Age of Russian Malacology. Collective volume of the All-Russia research conference dedicated to the 100th anniversary of the birth of Professor Viktor Nikolaevich Shimansky. Moscow-Saratov: Borissiak Paleontological Institute of the Russian Academy of Sciences – Yuri Gagarin Saratov State Technical University – «Kuznitza reclamy». P.235-248. [in Russian with English summary] pdf

d'Orbigny A. (1844) Paléontologie du Voyage de M. Hommaire de Hell // In: Hommaire de Hell. Les steppes de la mer Caspienne, le Caucase, la Crimée et la Russie méridionale. Voyage pittoresque, historique et scientifique, T.3. Paris. P.419-491. pdf

Rogov M.A. (2016) Ammonites and infrazonal stratigraphy of the Lower-Middle Callovian boundary beds of the Mountain Crimea (preliminary data) // Golden Age of Russian Malacology. Collective volume of the All-Russia research conference dedicated to the 100th anniversary of the birth of Professor Viktor Nikolaevich Shimansky. Moscow-Saratov: Borissiak Paleontological Institute of the Russian Academy of Sciences – Yuri Gagarin Saratov State Technical University – «Kuznitza reclamy». P.249-255. [in Russian with English summary] pdf

Rousseau L. (1842) Description des principaux fossiles de la Crimée // In: Demidoff A. Voyage dans la Russie meridoniale et la Crimée, par la Hongrie, la Valachie et la Moldavie, exécuté en 1837. T.2. Paris: Bourdin. P.781–819. pdf

Sandoval J. (2016) Ammonite assemblages and chronostratigraphy of the uppermost Bajocian–Callovian (Middle Jurassic) of the Murcia Region (Betic Cordillera, south-eastern Spain) // Proc. Geol. Assoc., http://dx.doi.org/10.1016/j.pgeola.2015.11.007

30.11.2015 - new information about publications is added, including full-texts:

Ippolitov A., Gulyaev D. (2015) Integrated ammonite-belemnite infrazonal scales as instrument for detailed stratigraphy (an example from the Lower Callovian of Russian platform) // 2-nd International Congress on Stratigraphy. STRATI 2015. Abstracts. Ber. Inst. Erdwiss. K.-F.-Univ. Graz. Bd 21. P. 176. pdf

Mitta V.V., Dietl G., Callomon J.H., Schweigert G., Dietze V. (2015) The ammonite genus Cadoceras (Cardioceratidae) in the Lower Callovian (Middle Jurassic) of the Swabian Alb and the Wutach area (Southern Germany) // Neues Jahrbuch für Geologie und Paläontologie – Abhandlungen. Vol. 278, No. 3, P. 303-321.

Seyed-Emami K., Raoufian A., Mönnig E. (2015) Macrocephalitinae (Ammonoidea, Middle Jurassic) from North and Central Iran // Neues Jahrbuch für Geologie und Paläontologie – Abhandlungen. Vol.278, No. 3, P. 257-279.

Tesakova E.M., Ippolitov A.P., Gulyaev D.B. (2015) Ostracode-based reconstruction of the Early Callovian events of the Kanev dislocations area (preliminary results) // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All-Russian meeting. September 15-20, 2015, Makhachkala. Scientific materials. V.A. Zakharov (ch. ed.), M.A. Rogov, A.P. Ippolitov (eds.). Makhachkala: ALEF. P.273-277. [in Russian] pdf

26.10.2015 - Macrocephalites discussion chart (by Eckhard Moennig) was added:

download as pdf

03.10.2015 - some new papers as well as discussion charts / synonimics (received from Eckhard Moennig) are added:

download chart as pdf

Synonymlist for Subgenus Kepplerites (by E. Moennig)

Gulyaev D.B. (2015) On the Callovian in the upper reaches of the Unzha river (Kologriv district, Kostroma region) // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All-Russian meeting. September 15-20, 2015, Makhachkala. Scientific materials. V.A. Zakharov (ch. ed.), M.A. Rogov, A.P. Ippolitov (eds.). Makhachkala: ALEF. P.84-93. [in Russian] pdf

Gulyaev D.B. (2015) Stratigraphy of the Bathonian‐Callovian nearboundary deposits of European Russia // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All-Russian meeting. September 15-20, 2015, Makhachkala. Scientific materials. V.A. Zakharov (ch. ed.), M.A. Rogov, A.P. Ippolitov (eds.). Makhachkala: ALEF. P.94-101. [in Russian] pdf

Gulyaev D.B., Guzhov A.B., Beketova Y.A. (2015) New data on the heteromorph ammonites of the genus Parapatoceras from the Lower Callovian of European Russia // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All-Russian meeting. September 15-20, 2015, Makhachkala. Scientific materials. V.A. Zakharov (ch. ed.), M.A. Rogov, A.P. Ippolitov (eds.). Makhachkala: ALEF. P.104-106. [in Russian] pdf

Makhnach V.V., Tesakova E.M. (2015) Palaeogeographic reconstructions of the natural environment in southeast Belarus during the Bathonian-Oxfordian ages // Moscow University Geology Bulletin, Vol.70. P.159-170. pdf

Meledina S.V., Knyazev V.G., Marinov V.A., Alifirov A.S., Igolnikov A.E. (2015) New data on the Jurassic ammonite stratigraphy of Yurung-Tumus Peninsula // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All-Russian meeting. September 15-20, 2015, Makhachkala. Scientific materials. V.A. Zakharov (ch. ed.), M.A. Rogov, A.P. Ippolitov (eds.). Makhachkala: ALEF. P.184-190. [in Russian]

Mitta V.V. (2015) On some “non-cardioceratid” taxa of the Early Callovian Сardioceratidae (Ammonoidea) // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All-Russian meeting. September 15-20, 2015, Makhachkala. Scientific materials. V.A. Zakharov (ch. ed.), M.A. Rogov, A.P. Ippolitov (eds.). Makhachkala: ALEF. P.191-194. [in Russian]

Temirbekova U.T., Barkueva L.S. (2015) Biostratigraphy of the Cаllovian deposits of Daghestan // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All-Russian meeting. September 15-20, 2015, Makhachkala. Scientific materials. V.A. Zakharov (ch. ed.), M.A. Rogov, A.P. Ippolitov (eds.). Makhachkala: ALEF. P.264-267. [in Russian]

Tesakova E.M. (2015) Correlation of the Middle-Late Jurassic ostracod scales of Western and Eastern Europe // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All-Russian meeting. September 15-20, 2015, Makhachkala. Scientific materials. V.A. Zakharov (ch. ed.), M.A. Rogov, A.P. Ippolitov (eds.). Makhachkala: ALEF. P.272-276. [in Russian] pdf

03.06.2015 - some new papers are added to the library:

Ivankić Z. (2004): Mittel-Jura-Ammoniten der ICE-Trasse München-Nürnberg bei Greding (humphriesianum- bis macrocephalus-Zone). Augsburg. 40 S. pdf

Stephanov, J. (1961): The Bathonian in the section of Belogradcik-Gora Oreshets road (North West Bulgaria) // Bull. Geol. Inst. 9: 337-370. pdf

Zaton M. (2010) Bajocian-Bathonian (Middle Jurassic) ammonites from the Polish Jura. Part 1: Families Phylloceratidae, Nannolytoceratidae, Sonniniidae, Strigoceratidae, Oppeliidae and Lissoceratida // Palaeontographica, Abt. A. Vol. 292, Iss. 4-6. P.65-113. pdf

Zaton M. (2010) Bajocian-Bathonian (Middle Jurassic) ammonites from the Polish Jura. Part 2: Families Stephanoceratidae, Perisphinctidae, Parkinsoniidae, Morphoceratidae and Tulitidae // Palaeontographica, Abt. A. Vol. 292, Iss. 4-6. P.115-213. pdf

06.04.2015 - new short papers are added:

Gulyaev D.B. (2015) Ammonites of the genus Bullatimorphites (Tulitidae) from the Lower Callovian of the Kanev dislocation area, Central Ukraine Contributions to current cephalopod research: Morphology, Systematics, Evolution, Ecology and Biostratygraphy. Proceeding of conference (Moscow, 2-4 April, 2015); Russian Academy of Sciences, Borissiak Paleontological Institute; eds. T.B. Leonova, I.S. Barskov,V.V.Mitta. P.95-96. pdf

Gulyaev D.B. (2015) On the neo-endemic Early Callovian Eastern Europe lineage of ammonites of the subfamily Macrocephalitinae (Sphaeroceratidae) and revision of its representative Macrocephalites multicostatus (Paryshev) // Contributions to current cephalopod research: Morphology, Systematics, Evolution, Ecology and Biostratygraphy. Proceeding of conference (Moscow, 2-4 April, 2015); Russian Academy of Sciences, Borissiak Paleontological Institute; eds. T.B. Leonova, I.S. Barskov,V.V.Mitta. P.36-39. pdf

Gulyaev D.B., Rogov M.A. (2015) The Boreal Lower Callovian ammonites of Crimea // Contributions to current cephalopod research: Morphology, Systematics, Evolution, Ecology and Biostratygraphy. Proceeding of conference (Moscow, 2-4 April, 2015); Russian Academy of Sciences, Borissiak Paleontological Institute; eds. T.B. Leonova, I.S. Barskov,V.V.Mitta. P.97-99. pdf

Mitta V.V. (2015) On the phylogeny of the Middle Jurassic Arctocephalitinae and Cadoceratinae (Cardioceatidae, Ammonoidea) // Contributions to current cephalopod research: Morphology, Systematics, Evolution, Ecology and Biostratygraphy. Proceeding of conference (Moscow, 2-4 April, 2015); Russian Academy of Sciences, Borissiak Paleontological Institute; eds. T.B. Leonova, I.S. Barskov,V.V.Mitta. P.32-35. pdf

13.03.2015 - new article is uploaded:

Dietze V., Schweigert G., Dietl G. (2014) Chrono-/Biostratigraphie im Mitteljura von SW-Deutschland. 2. Teil: Bathonium // Jh. Ges. Naturkde. Württemberg. Bd. 170. Nr.1. S. 191–203. pdf

possible alternative version of the Bathonian-Callovian chart by Mönnig (end of the February 2015) with comments by Gulyaev is added:

http://ejurassic.ucoz.ru/_fr/9/7149888.jpg

27.02.2015 - new article is uploaded:

Jain S., Desai B. (2014) Biostratigraphic implications of the discovery of Late Bathonian Indonesian ammonite Macrocephalites Cf. Mantataranus Boehm [M] From the core of Jara Dome, Kachchh, Western India // Journal of the Palaeontological Society of India. Vol.59. no.2. P.1-11. pdf

19.02.2015 - some charts & discussion are added to "Current Researches", discussion is also open at the jurassic.ru online forum

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II. Current researches

Discussion on the Bathonian/Callovian boundary is open now at: http://ejurassic.ucoz.ru/forum/25/

The following charts and schemes are available for further discussion:
Bathonian / Callovian Correlation Chart of Southern Germany, Northern Caucasus, Russian Platform and East Greenland successions (by Mönnig, February 2015)
http://ejurassic.ucoz.ru/_fr/9/Bathon_Callov_V.pdf

Succession of Kepplerites across the Bathonian / Callovian boundary of Southern Germany (by Mönnig, February 2015)
http://ejurassic.ucoz.ru/_fr/9/Kepplerites_Sdd.pdf

Bathonian / Callovian Correlation Chart of Subboreal Europe and E. Greenland (with notes) (by Gulyaev, February 2015)
http://ejurassic.ucoz.ru/_fr/9/1Gulyaev_Bt-Cl_.pdf

Correlation of local sections of Bathonian-Callovian boundary interval of European Russia (by Gulyaev, February 2015)
http://ejurassic.ucoz.ru/_fr/9/2Gulyaev_Bt-Cl_.pdf

new version of the Bathonian-Callovian chart by Mönnig (end of the February 2015) with comments by Gulyaev:

http://ejurassic.ucoz.ru/_fr/9/Monnig_Bth-Cl_V.pdf

TO THE TOP OF PAGE

III. References

Bathonian / Callovian boundary - Selection of recent literature

Definition of the Callovian Stage

Ager, D. V. (1963): Jurassic stages // Nature, 198: 1045-1046.

Arkell, W. J. (1933): The Jurassic System in Great Britain. Oxford University Press, Oxford, 681 p. pdf

Arkell, W. J. (1946): Standard of the European Jurassic // Bulletin of the Geological Society of America, 57: 1-34.

Callomon, J.H., (1959): The ammonite zones of the Middle Jurassic beds of East Greenland // Geol. Mag. 96, 505-513. pdf

Callomon, J.H., (1964): Notes on the Callovian and Oxfordian Stages. In: Maubeuge, P.L. (ed.): Comptes rendues et Memoires, Colloque Jurassique Luxembourg 1962, p. 269-291. pdf

Callomon, J. H. (1965): Notes on Jurassic stratigraphical nomenclature. I. Principles of stratigraphical nomenclature // Reports of the Vllth Congress of the Carpatho-Balkan Geological Association, Sofia, part ii, 1: 81-85.

Callomon, J.H. (1971): On the type species of Macrocephalites Zittel, 1884, and the type specimen of Ammonites macrocephalus Schlotheim, 1813 // Palaeontology, 14: 114-130. pdf

d’Orbigny (1842-1851): Paléontologie Français. Description zoologique et géologique de tous les animaux mollusques et rayonnés fossils de France. Terrains oolithiques ou jurassique. I. Céphalopodes: 642 p., Paris (Masson). pdf

d’Orbigny (1852): Cours élémentaire de paleontology et de géologie stratigraphique, Vol. 2: 383-847, Paris (Masson). pdf

International Commission on Zoological Nomenclature (1984): Opinion 1275: Macrocephalites Zittel, 1884, and Ammonites macrocephalus Schlotheim, 1813 (Mollusca, Cephalopoda): placed on the Official Lists // Bull. zool. Nomencl. , 41: 34-35. pdf

Ogg, J.G. & Hinnov, L.A. (2012): Jurassic. In: Gradstein et. al. (eds.): The Geological Time Scale 2012, Vol. 2: 731-791. pdf

Oppel, A. (1856-1858): Die Juraformation Englands, Frankreichs und des südwestlichen Deutschlands: 857 p., Stuttgart (Ebner & Seubert). pdf

Bathonian / Callovian Northern America

Callomon, J.H. (1984): A review of the biostratigraphy of the post-Lower Bajocian ammonites of western and northern North America // In: Westermann, G.E.G. (ed.): Jurassic-Cretaceous biochronology and paleogeography of North America. Geol. Assoc. Canada Spec. Paper 47: 143-174. pdf

Frebold, H. (1961): The Jurassic Faunas of the Canadian Arctic. Middle and Upper Jurassic Ammonites // Bull. Geol. Surv. Canada 74, 43 p. pdf

Frebold, H. (1964): The Jurassic Faunas of the Canadian Arctic. Cadoceratinae // Bull. Geol. Surv. Canada 119, 27 p. pdf

Imlay, R. W. (1953): Callovian (Jurassic) ammonites from the United States and Alaska. Pt. 1. Western Interior United States // US Geol. Surv. Prof. Paper 249-A: 1–39. pdf

Imlay, R. W. (1953): Callovian (Jurassic) ammonites from the United States and Alaska. Pt. 2. Alaska Peninsula and Cook Inlet regions // US Geol. Surv Prof. Paper. 249-B: 1–108. pdf

Imlay, R. W. (1962): Jurassic (Callovian) Ammonites in Southern Alaska // US Geol. Surv. Prof. Paper 374-C: 1–31. pdf

Imlay, R. W. (1975): Stratigraphic Distribution and Zonations of Jurassic (Callovian) Ammonites in Southern Alaska // US Geol. Surv. Prof. Paper 836: 1–28. pdf

Poulton, T.P. (1987): Zonation and Correlation of Middle Boreal Bathonian to Lower Callovian (Jurassic) Ammonites, Salmon Cache Canyon, Porcupine River, Northern Yukon // Bull. Geol. Surv. Canada 358, 155. p. pdf

Yeh, K. & Pessagno, E.A. (2013): Upper Bathonian (Middle Jurassic) Radiolarians from Snowshoe Formation, east-central Oregon, USA // Collection and Research 26: 51-175. pdf

Bathonian / Callovian Greenland

Callomon, J.H. (1972): Jurassic System // In: An annotated map of the Permian and Mesozoic formations of East Greenland. Meddr om Grønl., 168, no.3, 15-20.

Callomon, J.H. (1984): The evolution of the Cardioceratidae (Jurassic ammonitina) // Spec. Pap. Palaeontology, 33: 49-90. pdf

Callomon, J.H. (1993): The ammonite succession in the Middle Jurassic of East Greenland // Bull. geol. Soc. Denmark, 40: 83-113. pdf

Callomon, J.H. (2003): The Middle Jurassic of western and northern Europe: its subdivisions, geochronology and correlations // In: INESON, J.R. & SURLYK, F. (eds), The Jurassic of Denmark and Greenland, Geological Survey of Denmark and Greenland Bulletin, 61–74. pdf

Callomon, J.H. (2005): Description of a new species of ammonite, Kepplerites tenuifasciculatus n.sp., from the Middle Jurassic, Lower Callovian of East Greenland. Appendix to Alsen, P. and Surlyk, F. Maximum Middle Jurassic transgression in East Greenland: evidence from new ammonite finds, Bjørnedal, Traill Ø // Geological Survey of Denmark and Greenland Bulletin 5, 42-49. pdf

Donovan, D.T. (1953): The Jurassic and Cretaceous Stratigraphy and Palaeontology of Traill Ø, East Greenland // Medd. om Grønland 111 (4): 1–150. pdf

Gulyaev D.B. (2015) On the neo-endemic Early Callovian Eastern Europe lineage of ammonites of the subfamily Macrocephalitinae (Sphaeroceratidae) and revision of its representative Macrocephalites multicostatus (Paryshev) // Contributions to current cephalopod research: Morphology, Systematics, Evolution, Ecology and Biostratygraphy. Proceeding of conference (Moscow, 2-4 April, 2015); Russian Academy of Sciences, Borissiak Paleontological Institute; eds. T.B. Leonova, I.S. Barskov,V.V.Mitta. P.36-39. pdf

Kiselev D.N. (2022) Ammonites and infrazonal stratigraphy of the boreal and subboreal Bathonian and Callovian // Transactions of the Geological Institute. Vol. 628. 667 p. [in Russian] pdf

Piasecki, S., Callomon, J.H. & Stemmerik, L. Jurassic dinoflagellate cyst stratigraphy of Store Koldewey, North-East Greenland // Geological Survey of Denmark and Greenland Bulletin 5, 99-112. pdf

Silva R.L., Alsen P. (2024) Stable carbon isotope chemostratigraphy of the base of the Callovian in Greenland // Gondwana Research. Vol. 136. P. 84-91. pdf

Spath, L.F. (1932): The invertebrate faunas of the Bathonian-Callovian deposits of Jameson Land (East Greenland) // Medd. Grønland, 87(7): 1-158. pdf

Bathonian / Callovian: Svalbard, North Sea

Callomon, J.H. (1976): Jurassic ammonites from the northern North Sea // Norsk geol. Tidsskr. 55: 373-386. pdf

Ershova, E.S. (1983): Explanatory notes for the biostratigraphical scheme of the Jurassic and Lower Cretaceous deposits of Spitsbergen archipelago. Leningrad: PGO Sevmorgeologia. 88 p. [in Russian] pdf

Sokolov, D. & Bodylevsky, W. (1931): Jura- und Kreidefaunen von Spitzbergen // Skrifter Svalbard Ishavet 35: 1–151 . pdf

Kopik, J. & Wierzbowski, A. (1988): Ammonites and Stratigraphy of the Bathonian and Callovian at Janusfjellet and Wimanfjellet, Sassenfjorden, Spitsbergen // Acta Paleontol. Polon. 33 (2): 145–168. pdf

Bathonian / Callovian Siberia

Bodylevskii, V.I. (1960): Callovian Ammonites of Northern Siberia // Zap. Leningr. Gorn. Inst. 37: 49–82. [in Russian] pdf

Kiselev D.N. (2022) Ammonites and infrazonal stratigraphy of the boreal and subboreal Bathonian and Callovian // Transactions of the Geological Institute. Vol. 628. 667 p. [in Russian] pdf

Knyazev, V.G., Kutygin, R.V., Meledina, S.V. (2009): The Upper Bathonian Ammonite Zonation of East Siberia // Stratigraphy and Geological Correlation. 17: 192–203. pdf

Knyazev, V.G., Kutygin, R.V., Meledina, S.V. (2010): New ammonite zonation of the Lower Callovian in North Siberia // Stratigraphy and Geological Correlation, 18: 392–410. pdf

Knyazev, V.G., Kutygin, R.V., Meledina, S.V. (2011): Zonal subdivision of Lower and Middle Callovian of the north of Siberia by ammonites (Cardioceratidae) // Otechestvennaya geologiya. No. 5. P.33-37. [in Russian] pdf

Knyazev, V.G. Meledina, S.V., Kutygin, R.V. & Dovgopolik, D.A. (2006): Upper Bathonian and Lower Callovian Zonal Succession in Arctic Yakutia // In: Paleontology, Biostratigraphy, and Paleobiogeography of the Boreal Mesozoic (Geo, Novosibirsk, 2006): 104–107; [in Russian]

Meledina, S.V. (1977): Ammonites and zonal stratigraphy of the Callovian of Siberia // Trans. Acad. Sci. USSR, Siber. branch, 356: 228 p. [in Russian] pdf

Meledina, S. V. (1991): Zonal Scale of the “Boreal Bathonian” – Lower Callovian of Siberia // Trans. Acad. Sci. USSR, Siber. branch, 769: 125–154. [in Russian]. pdf

Meledina, S.V. (1994): Boreal Middle Jurassic of Russia (Ammonites and Zonal Stratigraphy of the Bajocian, Bathonian and Callovian) (Nauka, Novosibirsk,) [in Russian]. djvu

Meledina, S. V. (1999): Ammonites from the Boreal Upper Bathonian of Kotel’nyi Island // Russ. Geol. Geophys. 40: 1374-1382. pdf

Meledina, S.V., Shurygin, B.N., Zlobina O.N., et al. (1991): Chekurovka Formation (Bathonian-Callovian) in the Stratotype // Trans. Acad. Sci. USSR, Siber. branch, 769: 5–36 [in Russian] pdf

Sei, I.I. & Kalacheva, E.D. (1992): Bathonian-Callovian Boundary in the Boreal and Subboreal Regions of Russia // Soviet Geol., 10: 47–52. [in Russian] pdf

Bathonian / Callovian Russian Platform

Alekseev, S.N., Repin, Yu.S. (1989): Problems of zonal subdivision of Lower Callovian of he Russian Platform // Methodical aspects of stratigraphical investigations in oil-and-gas basins (collection of scientific papers). Leningrad: VNIGRI: 122-134. [in Russian] pdf

Gerasimov, P.A., Mitta, V.V., Kochanova, M.D., Tesakova, E.M. (1996): Fossils of the Callovian Stage of Central Russia. Moscow: VNIGNI. 127 p. [in Russian] pdf

Gulyaev, D.B. (1997): New Ammonites of the Family Cardioceratidae from the Lower Callovian of the Russian Platform // Paleontological Journal. V. 31. No. 1. P. 35-41.

Gulyaev, D.B. (1999): Macrocephalitinae and Gowericeratinae (Ammonoidea) from the Elatmae Zone and the stratigraphy of the Lower Callovian of Central areas of Russian Platform // Problems of the Mesozoic Stratigraphy and Palaeontology. Lecturing in Memory of M.S. Mesezhnikov. St-Petersburg: VNIGRI publ. P.63-85. [In Russian]. pdf

Gulyaev, D.B. (2001): Infrazonal ammonite scale for the Upper Bathonian. Lower Callovian of central Russia // Stratigraphy and Geological Correlation, 9: 65-92. pdf

Gulyaev D.B. (2005): Infrazonal subdivision of the Upper Bathonian and Lover Callovian of the East-European Platform by ammonites // Materials of the first All-Russian Meeting “Jurassic System of Russia: problems of stratigraphy and paleogeography”. Moscow: GIN RAS. P. 64-70. [in Russian] pdf (the entire volume)

Gulyaev, D.B. (2007): New data on ammonite biostratigraphy of the Upper Bathonian and Lower Callovian deposits of Churkinskaya Stchelya reference stratigraphic section (Pizhma River, river basin of Pechora) // Jurassic System of Russia: problems of stratigraphy and paleogeography. Second All-Russian Meeting: scientific reports. Yaroslavl: YSPU publ. P. 49-58. [in Russian] pdf (the entire volume)

Gulyaev D.B., Kiselev D.N. (1999 a): The Boreal Marine Upper Bathonian in the Central Part of the Russian Steppe // Doklady Earth Sciences. V. 367. No. 5. P. 641-644.

Gulyaev, D.B., Kiselev, D.N. (1999 b): Boreal Upper Bathonian in the Volga River Middle Courses (Ammonites and Stratigraphy) // Stratigraphy and Geological Correlation. V. 7. No. 3. P. 279-293. pdf

Gulyaev, D.B., Kiselev, D.N., Rogov, M.A. (2002): Biostratigraphy of the Upper Boreal Bathonian and Callovian of European Russia // 6-th Intern. Symposium on the Jurassic System, Mondello, September 16-19, 2002. Abstracts and Program. P. 81-82. pdf

Gulyaev D.B. (2009) The evolution and stratigraphic significance of the Middle Jurassic boreal genus Paracadoceras (Cardioceratidae, Ammonoidea) // Contributions to current Cephalopod research: morphology, systematics, evolution, ecology and biostratigraphy. Moscow: PIN RAS. P. 107-109. [in Russian]. pdf of the entire volume

Gulyaev D.B. (2011) The evolution of ammonite genus Paracadoceras and infra-zonal correlation of near-boundary Bathonian-Callovian deposits of Boreal regions // Paleontology, Stratigraphy and Paleogeography of the Mesozoic and Cenozoic of Boreal Regions. Vol. I. Mesozoic. Novosibirsk: P 74-78. [in Russian] pdf

Gulyaev D.B. (2012) On the revision of ammonites of the genus Paracadoceras (Cardioceratidae) from the Upper Bathonian and Lower Callovian of East Greenland // Contributions to current Cephalopod research: morphology, systematics, evolution, ecology and biostratigraphy. Moscow: PIN RAS. P. 69-72. [in Russian] pdf

Gulyaev D.B. (2013 a) New data on stratigraphy of the classical Callovian section near the village Alpat’evo (Oka river, Moscow Region) // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All‐Russian meeting. September 23-27, 2013, Tyumen. Scientific materials. (V.A.Zakharov (ch. ed.), M.A.Rogov, B.N.Shurygin (eds.). Yekaterinburg: “ID “IzdatNaukaServis” LLC, 2013. P.53-57. [in Russian] pdf

Gulyaev D.B. (2013 b) On ammonite zonal scale of the uppermost Bajocian, Bathonian and lowermost Callovian of the East Europe Platform // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All‐Russian meeting. September 23-27, 2013, Tyumen. Scientific materials. (V.A.Zakharov (ch. ed.), M.A.Rogov, B.N.Shurygin (eds.). Yekaterinburg: “ID “IzdatNaukaServis” LLC, 2013. P.58-64. [in Russian] pdf

Gulyaev D.B., Guzhov A.B., Beketova Y.A. (2015) New data on the heteromorph ammonites of the genus Parapatoceras from the Lower Callovian of European Russia // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All-Russian meeting. September 15-20, 2015, Makhachkala. Scientific materials. V.A. Zakharov (ch. ed.), M.A. Rogov, A.P. Ippolitov (eds.). Makhachkala: ALEF. P.104-106. [in Russian] pdf

Gulyaev D.B., Rogov M.A. (2009) Macrocephalitids (Sphaeroceratidae, Ammonoidea) in the Early Callovian of the East-European Subboreal Sea // Contributions to current Cephalopod research: morphology, systematics, evolution, ecology and biostratigraphy. Moscow: PIN RAS. P. 72-74. [in Russian] pdf

Kiselev D.N. (2022) Ammonites and infrazonal stratigraphy of the boreal and subboreal Bathonian and Callovian // Transactions of the Geological Institute. Vol. 628. 667 p. [in Russian] pdf

Kiselev, D.N. & Rogov, M.A. (2007): Sequence of Ammonites in Boundary Horizons of the Bathonian and Callovian of the Middle Volga Region // Jurassic System of Russia: Problems of Stratigraphy and Paleogeography, Yaroslavl: Izd_vo Yarosl. Gos. Ped. Univ.: 102–120. [in Russian] pdf (the entire volume)

Lahusen, I. (1883): Die Fauna der Jurassischen Bildungen des rjasanschen Gouverements // Mem. Com. Geol. V.1. no.1. 94 p. pdf

Meledina, S.V. (1986): Zonal subdivision of the Lower Callovian of Russian Platform // Bull. Ac. Sci. USSR. (Izv. AN SSSR), ser.geol. 7: 66-74. [in Russian] pdf

Meledina, S.V. (1987): Аmmonites and zonal stratigraphy of the Callovian of Subboreal regions of USSR // Transactions of the Institute of Geology and Geophysics, Siberian branch Ac. Sci USSR. 691: 1-182. [in Russian] pdf

Mitta, V.V. (2000): Ammonites and biostratigraphy of the Lower Callovian of the Russian Platform [in Russian] // Bulletin of CF VNIGNI, Moscow, 3: 1-144. [in Russian] pdf

Mitta, V.V. (2004): On the Evolution of Ammonites and Stratigraphy of the Boundary Beds of the Bathonian and Callovian in the Volga Basin // Ecosystem Reorganizations and Evolution of the Biosphere, Moscow: Paleontol. Inst. Ross. Akad. Nauk, 6: 125–136. [in Russian] pdf

Mitta, V.V. (2005): Paracadoceras keuppi Zone, a New Zone of the Upper Bathonian of the Russian Platform // Jurassic System of Russia: Problems of Stratigraphy and Paleogeography, Moscow: Geol. Inst. Ross. Akad. Nauk 2005: 158–160. [in Russian] pdf (the entire volume)

Mitta, V.V. (2005): Late Bathonian Cardioceratidae (Ammonoidea) from the Middle Reaches of the Volga River // Paleontol. J., Suppl. 39 (5): 629–644. pdf

Mitta, V. V. (2006): On the Bathonian–Callovian Boundary in the Boreal Scale. In: Materials of the Scientific Session Devoted to 95th Anniversary of the Birthday of V.N. Saks. ‒ Paleontology, Biostratigraphy, and Paleogeography of the Boreal Mesozoic (Geo, Novosibirsk, 2006): 113, 115–117 [in Russian].

Mitta, V. V. (2008): The Genus Kepplerites Neumayr et Uhlig (Kosmoceratidae, Ammonoidea) in the Bathonian–Callovian Beds (Middle Jurassic) of the Russian Platform // Paleontological Journal, l. 42/1: 5–14.

Mitta, V.V. (2009): Genus Eckhardites Mitta (Cardioceratidae, Ammonoidea) from the Lower Callovian of the Subboreal Jurassic // Paleontological Journal. 43 (1): 50–58. pdf

Mitta, V.V. (2015): On some “non-cardioceratid” taxa of the Early Callovian Сardioceratidae (Ammonoidea) // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All-Russian meeting. September 15-20, 2015, Makhachkala. Scientific materials. V.A. Zakharov (ch. ed.), M.A. Rogov, A.P. Ippolitov (eds.). Makhachkala: ALEF. P.195-198. [in Russian] pdf

Mitta, V.V. (2015): On the phylogeny of the Middle Jurassic Arctocephalitinae and Cadoceratinae (Cardioceatidae, Ammonoidea) // Contributions to current cephalopod research: Morphology, Systematics, Evolution, Ecology and Biostratygraphy. Proceeding of conference (Moscow, 2-4 April, 2015); Russian Academy of Sciences, Borissiak Paleontological Institute; eds. T.B. Leonova, I.S. Barskov,V.V.Mitta. P.32-35. pdf

Mitta, V. V. &. Starodubtseva, I. A. (1998): Field Work in 1998 and Biostratigraphy of the Lower Callovian of the Russian Platform // Vernadsky Mus. Novit., No. 2: 1–20. pdf

Mitta V. V. & Starodubtseva, I. A. (2000): V. A. Shchirovskii and the Study of the Mesozoic of the Alatyr–Kurmysh Region. ‒ Vernadsky Mus. Novit. 5: 1–20. pdf

Nikitin S.N. (1878) Grundschlüsse meiner Arbeit über die Gruppe Amaltheus funuferus Phill. // Bulletin de la Société impériale des naturalistes de Moscou. LIII (2): 81-159. pdf

Nikitin, S.N. (1881): Der Jura der umgegend von Elatma. 1 Lief. // Nouveaux Mémoires de la Société Impériale des Naturalistes de Moscou. XIV (2): 85-133. pdf

Nikitin, S.N. (1885): Der Jura der umgegend von Elatma. 2 Lief. // Nouveaux Mémoires de la Société Impériale des Naturalistes de Moscou. XV (2): 42-67. pdf

Repin, Yu.S. (2007): Ammonite scale for Pechora Jurassic // Bull. Soc. Natur Moscow, sect. geol. 82(2): 24-31. [in Russian] pdf

Repin, Yu.S. & Rashvan, N.H. (1996): Callovian ammonoids of the Saratov Volga area and Mangyshlak. Saint-Petersburg: NPO ‘Mir i semya-95’. 256 p. [in Russian] pdf

Repin, Yu.S., Zakharov, V.A., Meledina, S.V., Nalnyaeva, T.I. (2006): Atlas of the mollusks of the Pechora Jurassic // Bulletin of VNIGRI. 3: 1-262. [in Russian] pdf

Sasonov N.T. (1957): Jurassic deposits of the central areas of the Russian Platform. Leningrad. 155 p. [in Russian] pdf

Tesakova, E.M., Seltser, V.B. (2013): Ostracods and ammonites from Lower Callovian of Bartolomeevka section (Saratov region) // Bull. Soc. Natur. Moscow, sect. geol. 88 (2): 50-68. [in Russian] pdf

Tesakova E.M., Strezh A.S., Gulyaev D.B. (2009): New Lower Callovian Ostracodes from the Kursk Region // Paleontological Journal. 43 (3): 258-271. pdf

Proposed GSSP: Prosek section

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, 18: 42-62. pdf

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, 15: 485-515. pdf

Bathonian / Callovian Caucasus

Agaev, V.B. & Guseinov, G.M. (1972): The genus Kepplerites Neumayr et Uhlig from the Late Jurassic deposits of north-west Azerbaijan // Scientific reports of Azerbaijan State University, series geological-geographical sciences. 1: 38-41. [in Russian] pdf

Khimshiashvili, N.G. (1957): Upper Jurassic fauna of Georgia (Cephalopoda and Lamellibranchiata). Tbilisi: Ac. Sci. Georg. SSR publ.house. 313 p. [in Russian] pdf

Khimshiashvili, N.G. (1961): Connection of Late Jurassic molluskan fauna of Georgia with those of Northern Caucasus // Trans. Inst. Paleobiol. Ac. Sci. Georg. SSR. VI: 123-212. [in Russian] pdf

Khimshiashvili, N.G. (1967): Late Jurassic molluscan fauna of the Crimean-Caucasian region. Tbilisi: Metsniereba. 172 p. [in Russian] djvu

Lominadze, T.A. (1967): Callovian Macrocephalitidae of the Georgia and Northern Caucasus. Tbilisi: Mezniereba. 208 p. [in Russian] pdf

Lominadze, T.A. (1982): Callovian ammonitids of the Caucasus. Tbilisi: Metsniereba. 272 p. [in Russian] pdf

Lominadze, T.A. (2004): Callovian Cadoceratids of the Caucasus // Proc. Geol. Inst. Georgian Academy of Sciences. New. Ser. 119: 347–369. [in Russian] pdf

Lominadze, T.A. & Sakharov, A.S. (1982): Biostratigraphic scheme of the Caucasian Callovian deposits // Geology and prospecting of mineral deposits of Georgia. Transactions of the Georgian Polytechnic Institute, 3(248): 36-39. [in Russian] pdf

Lominadze, T.A. & Sakharov, A.S. (1984): Stratigraphical position of the Kepplerites gowerianus layers on the Northern Caucasus // Geology and prospecting of mineral deposits of Georgia. Transactions of the Georgian Polytechnic Institute, 11(281): 27-31. [in Russian] pdf

Lominadze, T.A. & Sakharov, A.S. (1985): Cosmoceratids of the Caucasus, Tbilisi: Metsniereba, [in Russian] pdf

Mitta, V.V. (2011): Ammonites from the Boundary Beds of the Bathonian–Callovian of the Northern Caucasus // Paleontology, Stratigraphy and Paleogeography of the Mesozoic and Cenozoic of Boreal Region, vol. 1: Mesozoic: 184–187.

Mitta, V. (2011): Ammonites of the Genus Cadoceras (Cardioceratidae) from the Uppermost Bathonian–Lowermost Callovian of the Northern Caucasus (Ingushetia) // Paleontological Journal, 45: 609–619. pdf

Tsereteli I.D. (1968) Bathonian ammonites of the Georgia. Tbilisi: Metsniereba. 98 p. [in Russian] pdf

Tsereteli I.D. (1989) Bathonian oppeliids of Transcaucasus. Tbilisi: Metsniereba. 112 p. [in Russian] pdf

Bathonian / Callovian Crimea

Baraboshkin E.Yu., Rogov M.A., Mileev V.S. (2010) On the characteristics of the Ammonitico Rosso facies in Callovian (Middle Jurassic) sediments near Planerskoe (East Crimea) // Moscow University Geology Bulletin. 65(4): 223–228. pdf

Gulyaev D.B., Rogov M.A. (2015) The Boreal Lower Callovian ammonites of Crimea // Contributions to current cephalopod research: Morphology, Systematics, Evolution, Ecology and Biostratygraphy. Proceeding of conference (Moscow, 2-4 April, 2015); Russian Academy of Sciences, Borissiak Paleontological Institute; eds. T.B. Leonova, I.S. Barskov,V.V.Mitta. P.97-99. pdf

Khimshiashvili, N.G. (1967): Late Jurassic molluscan fauna of the Crimean-Caucasian region. Tbilisi: Metsniereba. 172 p. [in Russian] djvu

Rogov, M.A., Mileev, V.S., Rosanov, S.B. (2002): Lower Callovian of East Crimea : new data on the ammonite fauna and biostratigraphy // Proc. of XVII. Congress of Carpathian-Balkan Geological Association Bratislava , September 1st - 4th 2002 and Guide to Geological Excursions. 6 p. pdf

Rogov, M.A. (2004): Outline of the biostratigraphy of the Middle-Upper Jurassic of the Sudak segment of the Mountain Crimea // in: Morozova A.L., Gnyubkin V.F. (Eds). Karagad. History, geology, botany. The scientific works dedicated to 90-th anniversary of T.V. Vyasemsky Karadag scientific station and 25-th anniversary of Karadag Nature Reserve. Book 1. Simferopol, Sonat: 84-93. [in Russian] pdf

Bathonian / Callovian Ukraine

Gricenko, V.P., Gulyaev, D.B., Ippolitov, A.P. (2013): Jurassic deposits of the Kanev Dislocations area as stratigraphical and palaeontological natural heritage // Stratigraphy of the sedimentary deposits of Upper Proterozoic and Phanerozoic. Materials of the International conference (Kiev, September 23-26, 2013). Kiev: LAT&K, 2013. P.53-54. [in Russian] pdf

Gulyaev D.B. (2015) Ammonites of the genus Bullatimorphites (Tulitidae) from the Lower Callovian of the Kanev dislocation area, Central Ukraine Contributions to current cephalopod research: Morphology, Systematics, Evolution, Ecology and Biostratygraphy. Proceeding of conference (Moscow, 2-4 April, 2015); Russian Academy of Sciences, Borissiak Paleontological Institute; eds. T.B. Leonova, I.S. Barskov,V.V.Mitta. P.95-96. pdf

Gulyaev, D.B., Ippolitov, A.P. (2013) Detailed biostratigraphy of the Lower Callovian of the Kanev district area (Cherkassy region, Ukraine) // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All‐Russian meeting. September 23-27, 2013, Tyumen. Scientific materials. (V.A.Zakharov (ch. ed.), M.A.Rogov, B.N.Shurygin (eds.). Yekaterinburg: “ID “IzdatNaukaServis” LLC. P.65-72. [in Russian] pdf

Gulyaev, D.B., Ippolitov, A.P., Gricenko, V.P. (2013): Jurassic deposits and detailed biostratigraphy of the Lower Callovian of Kanev Dislocations area (Cherkassy region) // Stratigraphy of the sedimentary deposits of Upper Proterozoic and Phanerozoic. Materials of the International conference (Kiev, September 23-26, 2013). Kiev: LAT&K. P.54-56. [in Russian] pdf

Gulyaev, D.B., Ippolitov, A.P., Kiselev, D.N. (2014): Jurassic geology and biostratigraphy of the Early Callovian in the Kanev district area (Cherkassy region, Ukraine) // 9th International Congress on the Jurassic System, Jaipur, India. Abstracts. Beringeria, Special Issue 8. P. 62-64. pdf

Ippolitov, A.P., Gulyaev, D.B. (2013): Belemnite stratigraphy of the Lower Callovian of south-west of Western Europe platform: preliminary results // Jurassic System of Russia: Problems of stratigraphy and рaleogeography. Fifth All‐Russian meeting. September 23-27, 2013, Tyumen. Scientific materials. (V.A.Zakharov (ch. ed.), M.A.Rogov, B.N.Shurygin (eds.). Yekaterinburg: “ID “IzdatNaukaServis” LLC, 2013. P.85-89. [in Russian] pdf

Ippolitov, A., Gulyaev, D. (2014): Infrazonal belemnite stratigraphy of the Lower Callovian of the East European Platform // Cephalopods - Present and Past 9 & Coleoids through Time 5, Zürich 2014 (Abstracts and program, Klug C., Fuchs D. (Eds.). Zürich, 2014. P.49. pdf

Karitzky, A. (1886): Der paläontologische Charakter der Jura-Ablagerungen der Umgegend von Traktomirow und Grigorowka im Gouvernement Kiew // Neues Jahrbuch für Mineralogie, Geologie und Palaentologie. I: 195-204. pdf

Karitzky, A. (1887): Ueber die verticale Vertheilung der Ammonitiden im Kiewer Jura // Neues Jahrbuch für Mineralogie, Geologie und Palaentologie. II: 57-63. pdf

Paryshev, A.V. (1977): On new Lower Callovian ammonites of the Middle Dnepr region // Paleontological collection. 14: 70-76. [in Russian] pdf

Bathonian / Callovian Belorussia

Makhnach, V.V., Tesakova, E.M. (2015): Palaeogeographic reconstructions of the natural environment in southeast Belarus during the Bathonian-Oxfordian ages // Moscow University Geology Bulletin, Vol.70. P.159-170. pdf

Bathonian / Callovian Northern Germany

Brand, E. & Mönnig, E. (2009): Litho & Biostratigraphie des Mittel-Jura (Dogger) in Bohrungen Norddeutschlands // Schriftenreihe der Deutschen Gesellschaft für Geowissenschaften, 54: 5-77.

Brand, E. et al. (1990): Zum Ober-Bathon (Mittlerer Jura) im Raum Hildesheim, NW- Deutschland // Geol. Jb., A 121: 1-323.

Mönnig, E. (1989): Stratigraphie und Fazies des Calloviums in NW-Deutschland // Clausthaler Geowissenschaftliche Diss. 37: 1-183.

Mönnig, E. (1995): Der Macrocephalen Oolith von Hildesheim // Mitteilungen aus dem Roemer-Museum Hildesheim, N. F., Abh. 5: 1-77. pdf

Mönnig, E. (2014): The stratigraphy of the Bathonian-Callovian boundary (Middle Jurassic) in Northern Germany // N. Jb. Geol. Paläont. Abh. 274 (2-3): 271–290.

Westermann, G. (1958): Ammonitenfauna und Stratigraphie des Bathonien NW-Deutschlands // Beih. geol. Jb., 32: 1-103. pdf

Bathonian / Callovian Southern Germany

Callomon, J. H., G. Dietl (1992): On the true stratigraphic position of Macrocephalites macrocephalus (Schlotheim, 1813) and the nomenclature of the Standard Middle Jurassic "Macrocephalus Zone" // Stuttgarter Beitr. Naturk., B 185: 1-65. pdf

Callomon, J.H., Dietl, G. & Page, K.N. (1988): On the ammonite faunal horizons and standard zonations of the Lower Callovian Stage in Europe // In: Rocha, R.B. & Soares, A.F. (eds): 2^nd International Symposium on Jurassic Stratigraphy, Lisboa 1987, 1: 359-376.

Callomon, J. H., Dietl, G., Galacz, A., Gradl, H., Niederhöfer H.-J., & Zeiss, A. (1987): Zur Stratigraphie des Mittel- und unteren Oberjuras in Sengenthal bei Neumarkt/Ofr. (Frankische Alb) // Stuttgarter Beitrage zur Naturkunde, B 132: 1-53. pdf (via biodiversitylibrary.org)

Dietl, G. (1981): Über Macrocephalites (Ammonoidea) aus dem Aspidoides-oolith und die Bathonium/Callovium-Grenzschichten der Zollernalb (SW-Deutschland) // Stuttgarter Beitr. Naturk., B 68: 1-15. pdf (via biodiversitylibrary.org)

Dietl, G. & Herold, G. (1986): Erstfund von Cadomites (Ammonoidea) im Unter-Callovium (Mittl. Jura) von südwest-Deutschland // Stuttgarter Beitr. Naturk., B 120: 1-9. pdf (via biodiversitylibrary.org)

Dietze, V., Schweigert, G., Callomon, J.H., Dietl, G. & Kapitzke, M. (2007): Der Mitteljura des Ipf-Gebietes (östliche Schwäbische Alb, Süddeutschland). Korrelation der süddeutschen Ammoniten- Faunenhorizonte vom Ober-Bajocium bis zum Unter-Callovium mit Südengland und Frankreich // Zitteliana, A47: 105-125. pdf

Dietze V., Schweigert G., Dietl G. (2014): Chrono-/Biostratigraphie im Mitteljura von SW-Deutschland. 2. Teil: Bathonium // Jh. Ges. Naturkde. Württemberg, 170 (1): 191–203. pdf

Ivankić Z. (2004): Mittel-Jura-Ammoniten der ICE-Trasse München-Nürnberg bei Greding (humphriesianum- bis macrocephalus-Zone). Augsburg. 40 S. pdf

Mönnig E. (2017) The evolution of Oppel’s ‘Macrocephalusbett’ (Callovian, Middle Jurassic). Lethaia, https://doi.org/10.1111/let.12220

Rieber, H. (1961): Ein Clydoniceras discus (Sow.) aus der „Fuscus-Bank“ der Südwestalb. // N. Jb. Geol. Paläont., Mh., 1961/2: 94-97.

Schairer, G. (1990): Einige Ammoniten aus dem ‘Orbis-Oolith’ (Oberbathon, Mittlerer Jura) von Sengenthal // Mitt. Bayer. Staatsslg. Paläont. Hist. Geol. 30: 15–26. pdf (via biodiversitylibrary.org)

Proposed GSSP Albstadt-Pfeffingen (Swabia, Southern Germany)

Beher, E., Brand, E. & Franz, M. (2010): Bathonian and Lower Callovian ostracodes of Albstadt-Pfeffingen (Middle Jurassic, Baden-Württemberg, Germany) // Palaeodiversity 3: 43-57. pdf

Callomon, J. H. & Dietl, G. (1990): Proposed definition of the Callovian Stage. Field Symposium in Swabia, Stuttgart/Albstadt (16-21 September, 1990) // ISJS, Callovian Working Group. ‒ xi + 20 pp., Stuttgart (unpublished). pdf

Callomon, J.H. (1991): Callovian Boundary Working-Group. Proposals for the designation of a Basal Boundary Stratotype (GSSP) and the definition of the Callovian Stage. Field Symposium held in Stuttgart and Albstadt-Ebingen, southern Germany, September 1990. // Newsletter of the International Subcommission on Jurassic Stratigraphy, 20: 5–9.

Callomon, J.H. & Dietl, G. (2000): On the proposed basal boundary stratotype (GSSP) of the Middle Jurassic Callovian Stage // In: Hall, R.L. & Smith, P.L. (eds.): Advances in Jurassic Research 2000. GeoResearch Forum, 6: 41-54. pdf (the entire volume)

Dietl, G. (1994): Der hochstetteri-Horizont - ein Ammonitenfaunen-Horizont (Discus Zone, Ober-Bathonian, Dogger) aus dem Schwäbischen Jura // Stuttgarter Beitr. Naturk., B 202: 1-39. pdf

Dietl, G., Mönnig, E., Schweigert, G. (2021): The ammonites of the keppleri Horizon (basal Callovian, Middle Jurassic) of Albstadt-Pfeffingen (Swabian Alb, Germany)–biostratigraphy and correlation // Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen, Bd. 302. Hft.1. P. 1-33.

Franz, M. & Knott, S.D. (2012): Foraminifera from the Callovian GSSP candidate section of Ablstadt-Pfeffingen (Middle Jurassic, Southern Germany) // N. Jb. Geol. Paläont. Abh., 264: 263-282.

Franz, M., Beher, E., Brand, E., Mönnig, E. (2010): The ostracode fauna of the section Albstadt-Pfeffingen (Baden Württemberg) // Earth Science Frontiers, Special Issue, 2012, Vol. 17: 49-50. pdf (the entire volume)

Franz, M., Beher, E., Dietl G. (2014): The Bathonian and Early Callovian Ostracoda of Baden-Wuerttemberg, southern Germany // N. Jb. Geol. Paläont. Abh., 274(2-3): 149-185.

Howarth, R. J. & McArthur J. M. (1997): Statistics for Strontium isotope stratigraphy: a robust LOWESS Fit to the marine Sr-isotope curve for 0 - 206 Ma, with look-up table for derivation of numeric age // Journal of Geology, 105: 441-456. pdf

Smelror, M. & Dietl, G. (1994). Dinoflagellate cysts of the Bathonian/Callovian boundary beds in southern Germany // Geobios, Memoire special, 17: 453-459.

Bathonian / Callovian Switzerland

Bitterli-Dreher P. (2020) Geologie und Paläontologie des Bergwerks Herznach. Teil 1: Die Erdgeschichte des «Meeresbodens» // Schweizer Strahler. Nr.2. S.22-31. pdf

Bitterli-Dreher P. (2021) Geologie und Paläontologie des Bergwerks Herznach. Teil 2: Die Erdgeschichte des Eisenerzes // Schweizer Strahler. Nr.4. S.22-33. pdf

Bitterli-Dreher P. (2023) Ein seltener Ammonit im Jurameer Mitteleuropas: Clydoniceras discus var. hochstetteri, Sow. 1813 // Schweizer Strahler. Nr.1. S.17-22. pdf

Dietl, G. & Gygi, R. (1998): Die Basis des Callovian (Mittlerer Jura) bei Liesberg BL, Nordschweiz // Eclogae geologicae Helvetiae, 91: 247-260. pdf

Hostettler, B. (2012): New lithostratigraphical units for the Callovian stage in the central Swiss Jura Mountains // Swiss Geoscience meetings 2012, Abstacts: 169-170. pdf (the entire volume)

Mangold, C & Gygi, R. (1997): Bathonian ammonites from Canton Aargau, Northern Switzerland: stratigraphy, taxonomy, and biogeography // Geobios, 30, 4: 497-518.

Bathonian / Callovian Poland

Dembicz, K. et al. (2006): Ogrodzieniec Quarry, uppermost Bathonian to Middle Oxfordian ammonite succession // In: Wierzbowski et al. (2006): Jurassic of Poland and adjacent Slowakian Carpathians (Field trip guidebook on the 7^th International Congress on the Jurassic System): 144-148, Warszawa (Polish Geological Institute).

Kopik, J. (1979): Callovian of the Częnstochowa Jura (South-Western Poland) // Prace Instytutu Geologicznego XCIII: 1-69. pdf

Kopik, J. (2006): Bathonian ammonites of the families Sphaeroceratidae Buckman and Tulitidae Buckman from the Polish Jura Chain (Southern Poland) // Polish Geological Institute Special Papers, 21: 1–68. text, plates

Neumayr, M. (1871-73): Die Cephalopoden-Fauna der Oolith von Balin bei Krakau // Abh. Geol. Reichsanst., 5/2: 19-54. pdf

Bathonian / Callovian Bulgaria

Howarth, M.K. & Stephanov, J. (1965): The Genus Kosmoceras in Bulgaria // Travaux sur la Géologie de Bulgare – Série Paléontologie VII: 135-149. pdf

Dommergues, J.-L., Marchand, D., Sapunov, I., Thierry, J. (1987): Les faunes d’ammonites du Jurassique bulgare: une confirmation paléobiogéographique de l’isolement relative de la region balkano-moesienne // Bull. Soc. Géol. France, (8), t. III, n° 4: 737-742.

Metodiev L. (2019) Rare and little-known ammonites from the Lower and Middle Jurassic of the Western and Central Balkan Mts (Bulgaria) // Geologica Balcanica. Vol. 48. no.1. P. 3–41. pdf

Metodiev L., Sapunov I. (2017) The ammonite zones of the Bathonian in Bulgaria // Geologica Balcanica. Vol. 46. no. 2. P. 57–63. pdf

Metodiev, L., Sapunov, I. (2019) Studia breviora: On the "Macrocephalites macrocephalus" Zone of the lower Callovian in NW Bulgaria // Geologica Balcanica. Vol. 48. no. 3. P. 43–47. pdf

Stephanov, J. (1961): The Bathonian in the section of Belogradcik-Gora Oreshets road (North West Bulgaria) // Bull. Geol. Inst. 9: 337-370. pdf

Bathonian / Callovian Serbia

Bathonian / Callovian Italy

Sturani, C. (1968): Segnalazione di faune calloviane nel “ross mammonitico” die Lessini veronesi // Bull. Soc. Geol. It., 87: 43-49.

Bathonian / Callovian England

Arkell, W. J. (1947): The Geology of Oxford: 267 p. Oxford (Oxford University Press).

Arkell, W.J. (1954): Three complete sections of the Cornbrash // Proc .Geol. Ass. , 65: 115-132.

Callomon, J. H. (1955): The ammonite succession in the Lower Oxford Clay and Kellaways Beds at Kidlington, Oxfordshire, and the Zones of the Callovian Stage // Philosophical Transactions of the Royal Society, London, 8239: 215-264,

Callomon, J.H. (1968): The Kellaways Beds and the Oxford Clay // In: P.C. Sylvester-Bradley & Ford, T.D. (eds.): The Geology of the East Midlands: 264-290; Leicester (University Press). pdf

Douglas, J. A. & Arkell, W. J. (1928): The stratigraphical distribution of the Cornbrash. I. The south-western area // Quarterly Journal of the Geological Society, London, 84: 117-178.

Douglas, J. A. & Arkell, W. J. (1932): The stratigraphical distribution of the Cornbrash. II. The south-western area // Quarterly Journal of the Geological Society, London, 88: 112-170.

Duff, K.L. (1980). Callovian correlation chart. In: Cope, J.C.W. (ed): A correlation of Jurassic rocks in the British Isles, part 2: Middle and Upper Jurassic // Geol. Soc. Lond. Spec. Repts, 15: 45-60. pdf (the entire volume)

Page, K. N. (1988): The Stratigraphy and Ammonites of the British Lower Callovian. Thesis unpublished pdf available for free through ethos.bl.uk

Page, K. N. (1989): A stratigraphical revision for the English Lower Callovian // Proceedings of the Geologists' Association, 100: 363-382. pdf

Page, K. N. (1996): Observations on the succession of stratigraphically useful ammonite faunas in the Bathonian (Middle Jurassic) of south-west England, and their correlation with a Sub-Mediterranean "Standard Zonation" // Proceedings of the Ussher Society, 9: 45-53. pdf

Bathonian / Callovian France

Branger, P. (2009): Buffevent (Deux-Sèvres), une nouvelle coupe de référence pour la base du Callovien // Nature entre Deux-Sèvres, 2: 52-58. pdf

Cariou, E. (1980): L'etage Callovien dans le centre-ouest de la France. These, Dr. Sci .nat. Univ. Poitiers, U. E. R. Sci. fond. appliquées, 325, 1. partie, 37p.

Cariou, E. (1985): Biostratigraphic subdivision of the Callovian Stage in the subtethyan province // In: International Symposium on Jurassic Stratigraphy, Erlangen 1984: 315-326, Copenhagen.

Mangold, C. (1970): Les Périsphinctidae (Ammonitina) du Jura médional au Bathonienet au Callovien // Docum. Lab. Géol. Fac. Sci. Lyon, 41/2: 1-246. pdf

Mangold, C. (1990): Le Bathonien du Cap Mondego (N de Figuera da Foz, Portugal): biochronologie et correlations // Cahiers Université Catholique de Lyon, série Sciences, 4: 89-105, Lyon.

Mangold C., Martin A., Prieur A, (2012) Les Périsphinctidés du Bathonien moyen et supérieur du Mâconnais (Saône-et-Loire, France) // Docum. Lab. Géol. Lyon, no. 169, 155 p. pdf

Martin A., Mangold Ch. (2015) Le genre Bullatimorphites du Bathonien moyen et supérieur du Mâconnais (Saône-etLoire, France) // Strata, série 2, Vol. 52, 119 p. pdf

Thierry, J. (1978): Le genre Macrocephalites au Callovien inférieur (Ammonites, Jurassique moyen) // Mémoires de l’Université de Dijon, 4: 491 p., Dijon. pdf

Thierry, J. (2003): Les ammonites du Bathonien-Callovien du Boulonnais: biodiversité, biostratigraphie et biogéographie // Geobios 36: 93-126. pdf

Thierry, J., Cariou, E., Elmi, S., Mangold, C., Marchand, D. & Rioult, M. (1997): Callovien. In: Groupe français d’Études du Jurassique: Biostratigraphie du Jurassique ouest-Européen et Méditerranéen, zonations parallèles et distribution des invertébrés et microfossiles // E. Cariou & P. Hantzpergue (eds), Bulletins du Centre de Recherches, Elf Exploration et Production, Mémoire 17:, 63-78. Pau. pdf

Zany, D., Atrops, F., Marchand, D., Thierry, J. (1990): Nouvelles données biostratigraphiques sur les series du Bathonien et du Callovien des environs de Digne (Alpes-de-Haute-Provence) // Géologie des Méditerraanéenne, XVIII, 1: 39-53. pdf

Bathonian / Callovian Portugal and Spain

Cariou, C., Mangold, C., Mouterde, R., Bordalo da Rocha, R., Ruget, C., Thierry, J. (1988): Biochronologie du Callovien inferieur et moyen de la province submediterraneenne: apport de la coupe du Cap Mondego (Portugal) // In: Rocha, R.B. & Soares, A.F. (eds): 2^nd International Symposium on Jurassic Stratigraphy, Lisboa 1987, 1: 407-418.

Fernández-López, S. (2001) Upper Bathonian ammonites of the Catalan Basin (Tivissa and Cap Salou, Spain) // Hantkeniana 3: 25-39. pdf

Meléndez, G., Ramajo, J., Bello, J. & Page, K.N. (2007): Callovian and the Callovian - Oxfordian transition sedimentary record in NE Iberian Chain: Taphonomic analysis and palaeogeography // Journal of Iberian Geology 33(2): 261-282. pdf

Page, K., Bello, J., Lardies, M.D., Melendez, G., Ramajo, J. & Zaini H. (2004): The stratigraphy of the Upper Bathonian to Middle Oxfordian succession of the aragonese branch of the Cordillere Iberica (Spain) and its European context // Rivista Italiana di Paleontologia e Stratigrafia. 110(1): 191-200. pdf

Rocha, R., Manuppella, G., Mouterde, R., Ruget, Ch. & Zbyszewski, G. (1981): Carta geológica de Portugal: notícia explicativa de folha 19-C, Figuera da Foz: 29-33; Lisbon, Serv. geol. Portugal.

Ruget-Perrot, Ch. (1961): Etudes stratigraphiques sur le Dogger et le Malm Inférieur du Portugal au nord du Tage // Mem. Serv. geol. Portugal, N. S., 7: 197 pp.

Bathonian / Callovian Hungary

Görög Á., Tóth E., Wernli R. (2012) Foraminifera and Ostracoda of the classic Callovian ammonite-rich bed of the Villány Mountains (Hungary) // Hantkeniana 7: 95-123.

Galácz A. (1980) Bajocian and Bathonian ammonites of Gyenespuszta Bakony Mts., Hungary // Geol. Hung. Ser. Paleont. Fasc. 39. 227 p. pdf

Galácz A. (2015) Macrocephalitid-bearing Lower Callovian (Middle Jurassic) beds in the Mecsek Mts (South Hungary) // Hantkeniana. Vol. 10, P.73–88. pdf

Galácz A., Földvári G. (2024) Heteromorph ammonite Parapatoceras from the Lower Callovian of Villány, South Hungary // Földtani Közlöny, Vol. 154. no. 1. P.59-63. pdf

Loczy L. (1915) Monographie der Villanyer Callovien-Ammoniten // Geol. Hung. T.1. Fasc. 3-4. S. 255-502. pdf

Bathonian / Callovian Africa and Arabian Peninsula

Arkell, W.J. (1952): Jurassic ammonites from Jebel Tuwaiq, Central Arabia // Phil. Trans. Roy. Soc. Lond., B 236: 257-313.

Elmi, S. (1971): Les Zone d’Ammonites dans la série Bajocien superior-Callovien de l’Oranie (Ouest algérien) // Bull. Soc. Géol de France, (7), XIII, 1971/1-2: 28-37.

Imlay, R.W. (1970): Some Jurassic ammonites from central Saudi Arabia // U. S. Geol. Surv. Prof. Pap. 643-D: 17 p. pdf

Bathonian / Callovian Iran

Dabbaghi Sadr F., Seyed-Emami K., Majidifard M. (2012) Biostratigraphy and Lithostratigraphy of the Middle and Late Jurassic Rocks West of Binalud Range Northwest of Neyshabour, Northeast Iran // Geosciences. Scientific Quarterly Journal. Vol. 22. no.85. P.35-47. [in Persian] pdf

Faridani M, Raisossadat S N, Majidifard M, BaBazadeh S A. (2013) Effects of sea level fluctuations on distribution and diversity of ammonites in the middle and upper Jurassic strata northwest of Neyshabur // Journal of Stratigraphy and Sedimentology Researches. Vol.28. no.4. P.81-94. [in Persian] pdf

Majidifard M.R. (2018) Callovian ammonites from northern Iran // Revista Brasileira de Paleontologia, 21(1):17–46. doi:10.4072/rbp.2018.1.02 pdf

Paknia M., Alimohammadian H., Majidifard M.R., Sabouri J., Aghanabat A. (2013) Magnetostratigraphy of Bathonian-Callovian Boundary (Middle Jurassic) of Golbini Section, Eastern Alborz, Iran // Geosciences. Scientific Quarterly Journal. Vol. 22. no.88. P.19-31. [in Persian] pdf

Sarbandi Farahani T., Majidifard M., Kebriaee-Zadeh M.R., Mohammadi M. (2015) Study of the Lithostratigraphy and Biostratigraphy of Ammonite Fauna of the Dalichai Formation at the Mahdishahr Section, N Semnan // Geosciences. Scientific Quarterly Journal. Vol. 24. no.94. P.27-39. [in Persian] pdf

Zadesmaeil M., Majidifard M.R., Vaziri S.H., Jahani D. (2017) Reineckeiidae (Ammonoidea) Family of the Dalichai Formation in Damghan Area (East Alborz), Iran // Open Journal of Geology, Vol.7, P.888-914. DOI: 10.4236/ojg.2017.76061 pdf

Bathonian / Callovian Indo-Malagsy Province

Callomon, J.H. (1993): On Perisphinctes congener Waagen, 1875, and the age of the Patchman Limestone in the Middle Jurassic of Jumura, Kutch, India // Geol. Bl. NO-Bayern, 43 (1993)/1-3: 227-246.

Collignon, M. (1958): Atlas des fossiles characteristiques de Madagaskar. Fasc. iii: Bathonien-Callovien. Tananarive, Serv. geol. pdf

Collignon, M. (1964): Échelle chronostratigraphique proposée por les Indo-Africano-Malgache (Bathonien moyena Tithonique) // In: Maubeuge, P.L. (ed.): Comptes rendues et Memoires, Colloque Jurassique Luxembourg 1962: 927-931, Luxembourg.

Fatmi, A.N. (1969): Lower Callovian ammonites from Wam Tangi, Nakus, Baluchistan. Memoirs of the Geological Survey of Pakistan // Palaeontologia Pakistanica, Vol. 8, 14 p. pdf

Jain, S. (2012): Integrated biostratigraphy and paleoenvironment of the Middle Jurassic sediments at Kuldhar (Jaisalmer), Western India // Journal of the Palaeontological Society of India. 57(1): 1-41. pdf

Jain, S. (2014): The Arkelli Chronozone: A new early Middle Bathonian standard ammonite zone for Kachchh, western India (southern Jurassic Tethys) // Zitteliana A, 54: 91-136. pdf

Jain S. (2019) On the occurrence of the Indonesian ammonite Macrocephalites keeuwensis Boehm [M & m] from Kachchh (Western India) // Zitteliana. Bd. 93. P.3-24. pdf

Jain S. (2020) Immigration of the genus Macrocephalites Spath and the Bathonian biostratigraphy of the Kachchh basin (Western India, South Tethys) // Zitteliana. Bd.94. P.3-36. pdf

Jain S. (2024) Note on the earliest records of genus Macrocephalites Zittel: implications for biostratigraphic correlations // Historical Biology, DOI 10.1080/08912963.2024.2345223 pdf

Jain, S., Desai, B. (2014): Biostratigraphic implications of the discovery of Late Bathonian Indonesian ammonite Macrocephalites Cf. Mantataranus Boehm [M] From the core of Jara Dome, Kachchh, Western India // Journal of the Palaeontological Society of India. 59 (2): 1-11. pdf

Krishna, J. (1983): Callovian-Albian ammonoid stratigraphy and palaeobiogeography in the Indian Subcontinent with special reference to the Tethys Himalaya // Himal. Geol., 11, 43-72. pdf

Krishna, J. & Cariou, E. (1986): The Callovien of Western India: New das on the biogeostratigraphy, biogeography of the ammonites and correlation with western Tethys (Submediterranean Province) // Newsl. Stratig., 17/1: 1-8.

Krishna, J., Cariou, E. & Enay, R. (1988): Succession of Macrocephalitinae assemblages as revealed at Keera Dome in Kachchh, Western India // In: Rocha, R.B. & Soares, A.F. (eds): 2^nd International Symposium on Jurassic Stratigraphy, Lisboa 1987, 1: 384-394.

Krishna, J. & Ojha, J.R. (1996): The Callovian Ammonoid Chronology in Kachchh (India) // in: Riccardi A. (Ed.) Advances in Jurassic Research. GeoResearch Forum. V.1-2. Uetikon-Zurich: Transtech Publ. 151-166. pdf

Krishna, J. & Westermann, G.E.G (1985): Progress report on the Middle Jurassic ammonite zones of Kachchh, W India // Newls. Stratigr 14/1: 1-11.

Krishna, J. & Westermann, G.E.G (1987): Faunal association of the Middle Jurassic ammonite genus Macrocephalites in Kachchh, western India // Can. J. Earth Sci., 24: 1570-1582.

Sharma J.K., Pandey D.K. (2016) Taxonomy of Late Bathonian-Oxfordian ammonites from the Jaisalmer basin: Implications for intrabasinal litho- and biostratigraphic correlations // Journal of the Palaeontological Society of India. Vol.61. no.2. P.249-266. pdf

Bathonian / Callovian Indonesia

Westermann, G.E.G. & Callomon, J.H. (1988): The Macrocephalitinae and associated Bathonian and early Callovian (Jurassic) ammonoids of the Sula Islands an New Guinea // Palaeontographica Abt. A, 203/1-3: 1-90. pdf

Westermann, G.E.G., Sato, T. & Swarko, S.K. (1978): Brief report on the Jurassic biostratigraphy of the Sula Islands, Indonesia // Newsl. Stratigr., 7: 96-101.

Bathonian / Callovian Japan

Handa, N., Nakada K., Anso, J. & Matsuoka A. (2014) Bathonian/Callovian (Middle Jurassic) ammonite biostratigraphy of the Kaizara Formation of the Tetori Group in central Japan // Newsletters on Stratigraphy, 47(3): 283–297.

Bathonian / Callovian China (Tibet)

Zeng, S.Q., Wang, J., Chen, M., Fu, X.G., Xiong, X.G. (2012): The discovery of Late Bathonian – Early Callovian ammonites in the middle of northern Qiangtang basin, Tibetan plateau // Geological Bulletin of China 31: 521-527. [in Chinese ] pdf

Bathonian / Callovian South America

Gröschke, M. & Hillebrandt, A. v. (1985): Trias und Jura in der mittleren Cordillera Domeyko von Chile (23° 30'-24°30') // N. Jb. Geol. Paläont. Abh. 170/2: 129-166.

Hillebrandt, A. v. (1993): Die paläobiogeographischen Beziehingen zwischen Nordchile und Europ im mittleren Jura // Geol. Bl. NO-Bayern, 43 (1993)/ 1-3: 57-72.

Kamo S.L., Riccardi A.C. (2009) A new U–Pb zircon age for an ash layer at the Bathonian–Callovian boundary, Argentina // GFF, Vol. 131. no.1-2, P.177-182. pdf

Riccardi, A.C., Westermann, G.E.G. & Elmi, S. (1989): The Middle Jurassic Bathonia-Callovian Ammonites Zones of the Argentine-Chilean Andes // Geobios, 22/5: 553-597.

Westermann, G.E.G., Riccardi, A.C., Palacios, O. & Rangel C. (1980): Jurasico Medio en el Peru // Bol. Inst. Geol. Minero y Metalurgico. Serie D, Estudios Especiales 9: 1-47. pdf

Stratigraphical procedure

Aubry, M.-P., Berggren, W.A., Van Couvering, J.A. & Steininger, F. (1999): Problems in chronostratigraphy: stages, series, unit and boundary stratotypes, global stratotype section and point and tarnished golden spikes // Earth-Science Reviews, 46: 99-148.

Callomon, J. H. (1985): Biostratigraphy, chronostratigraphy and all that – again // In Michelsen, O. & Zeiss, A. (eds.): International Symposium on Jurassic Stratigraphy, Erlangen, 3: 611-624, Copenhagen (Geological Survey of Denmark).

Callomon, J. H. (1994): Palaeontological methods of stratigraphy and biochronology: some introductory remarks // Geobios, Memoire special, 17: 16-30.

Callomon, J.H. (1995) Time from fossils: S.S. Buckman and Jurassic high-resolution geochronology // In Le Bas, M.J. (ed.), Milestones in Geology, Geological Society, London, Memoir 16: 127-150. pdf

Callomon, J.H. (2003): Essay Review: Stratigraphical Procedure, by P.F. Rawson (ed.) and 16 others, Professional Handbook series, Geological Society, London (2002) // Proceedings of the Geologists’ Association, 114: 263–269.

Cowie, J. W., Ziegler, W., Boucot, A. J., Bassett M.G., & Remane, J. (1986): Guidelines and Statutes of the International Commission on Stratigraphy (ICS) // Courier des Forschungsinstitut Senckenberg, 83: 1-14. pdf

Gradstein, F.M., Ogg, J.G., Schmitz, M.D., Ogg, & G.M. (eds.) (2012): The Geological Time Scale 2012, Vol 1: 435 pp., Oxford (Elsevier).

Guex, J. (1991): Biochronological correlations: 252 p, Springer Verlag, pdf

Hedberg, H.D. (1954): Procedure and terminology in stratigraphic classification // Congres Geologique International: Comptes rendus de la XIX Session, Alger 1952. Section XIII, lere partie: Fase, xiii: 205-233.

Remane, J. (1996): The revised Guidelines of ICS and their bearing on Jurassic chronostratigraphy // GeoResearch Forum, Transtec Publications, Switzerland, 1-2: 19-22.

Remane, J., M. G. Bassett, J. W. Cowie, K. H. Gohrbandt, H. R., Lane, O. Michelsen, & Wang Naiwen (1996): Revised guidelines for the establishment of global chronostratigraphic Standards by the International Commission on Stratigraphy (ICS) // Episodes, 19: 77-81. pdf

Sadler, P. M., & Strauss, D. J. (1990): Estimation of completeness of stratigraphical sections using empirical data and theoretical models // Journal of the Geological Society, London, 147: 471- 485.

Schindel, D.E. (1980): Microstratigraphic sampling and limits of paleontologic resolution // Paleobiology, 6: 407-426.

Schindel, D. E. (1982): Resolution analysis: a new approach to the gap in the fossil record // Paleobiology, 8: 340-353.

TO THE TOP OF PAGE

IV. Callovian WG reports

Reports of the Callovian Working Group

1984 REPORT OF THE CALLOVIAN WORKING GROUP, by John CALLOMON

In: Michelsen, O. & Zeiss, A.: International Symposium on Jurassic Stratigraphy, Erlangen, Symposium Volume I: 77-86 (1984)

1994 REPORT OF THE CALLOVIAN WORKING GROUP, by John CALLOMON

ISJS Newsletter 22: 40 (1994)

1995-1998 (?)

1999 REPORT OF THE CALLOVIAN WORKING GROUP, by John CALLOMON

ISJS NEWSLETTER 27: 1 (1999)

2001 REPORT OF THE CALLOVIAN WORKING GROUP; by John CALLOMON

ISJS NEWSLETTER 28: 8-10 (2001)

2002 REPORT OF THE CALLOVIAN WORKING GROUP, by John CALLOMON

ISJS NEWSLETTER 29: 10-11 (2002)

2003 REPORT OF THE CALLOVIAN WORKING GROUP, by John CALLOMON

ISJS NEWSLETTER 30: 16 (2003)

2004 REPORT OF THE CALLOVIAN WORKING GROUP, by John CALLOMON

ISJS NEWSLETTER 31: 9 (2004)

2005 REPORT OF THE CALLOVIAN WORKING GROUP, by John CALLOMON

ISJS NEWSLETTER 32: 14 (2005)

2006 REPORT OF THE CALLOVIAN WORKING GROUP, by John CALLOMON

ISJS NEWSLETTER 33: 16 (2006)

2007 REPORT OF THE CALLOVIAN WORKING GROUP, by John CALLOMON and Gerd DIETL, Convenors

ISJS NEWSLETTER 34/2: 14-16 (2007)

2008 REPORT OF THE CALLOVIAN WORKING GROUP, by John CALLOMON

ISJS Newsletter 35/2 (2008)

2014 Report of the Callovian Stage Task Group, 2013, by Eckhard Moennig

Volumina Jurassica, Vol. XII. no.1. P.197–200. (2014) pdf

Dr. Gerd Dietl during the Callovian WG Meeting (1991)

Report of the Callovian Working Group.

By J.H. Callomon: In: Michelsen, O. & Zeiss, A.: International Symposium on Jurassic Stratigraphy, Erlangen, September 1-8, 1984, Symposium Volume I: 77-86. Copenhagen 1984.

Abstract. - The proceedings of the first meeting of the Callovian Working-Group of the International Subcommission on Jurassic Stratigraphy held at Erlangen in September 1984 are summarized. A Statement of the present Status of the rather well-established definition of the Callovian Stage and its boundaries is followed by a brief review of some of the major developments and Problems in Callovian stratigraphy in various parts of the world.

A. ORGANIZATIONAL

The Callovian Working-Group was set up in 1983 and, at the invitation of the President and Secretary of the Subcommission, J.H. Callomon agreed to act as co-ordinator. The first meeting was held during the Symposium at Erlangen on 7 September 1984. From among those present and others, some 40 expressed a desire to join the Working Group, either as active members at present working on problems of Callovian stratigraphy, or as passive members interested but not immediately involved in the Callovian. Membership is not restricted, and readers of this report not present at Erlangen wishing to join are cordially invited to do so by informing the co-ordinator.

The future programme of the Working-Group is envisaged to be primarily one of disseminating information. To this end, the co-ordinator agreed to act as central post-box and forwarding-agent for enquiries. He did not think that it would be practical for the Working-Group per se to initiate programmes of active work on outstanding stratigraphical problems, for it disposes neither of the manpower nor of the material resources needed to support such ventures. It should however be in a strong position to identify and formulate the problems to be tackled by individuals as the opportunities arise.

The main part of the meeting was then taken up by a brief review by the co-ordinator of the present Status of the chronostratigraphic zonation of the Callovian Stage. This is summarized below.

B. DEFINITION AND STANDARD ZONATIONS

For purposes of refined chronostratigraphy, ammonites have so far had no serious challengers in the Callovian. They form the basis of what appears to have been the first zonation of a Jurassic Stage according to the principles summarized elsewhere in this volume, down to the level of the typological definition of the lowest units in the hierarchy, the Subzones.

(1) European Sub-Boreal zonation.

The Standard European Sub-Boreal zonal scale put forward at the first Luxembourg Colloquium (Callomon 1964) has stood the test of time almost unchanged. It was based to a considerable degree on the classical work of Brinkmann in the Oxford Clay of Peterborough (adapted as explained in Callomon, 1968), and has been modified mainly by refinement in those parts of the succession now better known. The present scale is presented in the Geological Society of London's Correlation Charts (Duff 1980)(figure l(a)), and is at present almost universally accepted as the primary Standard. It defines the Callovian Stage in terms of the lower boundary stratotype of the basal Macrocephalus Subzone of the Macrocephalus Zone, taken (rightly or wrongly, for reasons explained in Callomon, 1964) at the base of bed 4, Upper Cornbrash, Sutton Bingham, Somerset, England (Arkell 1954). One of the uncertainties relating to the subzonal index has since been resolved. The interpretation of M. macrocephalus in terms of a neotype proposed by Callomon, 1971, has been validated by the ICZN in Opinion 1275 (ICZN, 1984). The other, whether this species in fact occurs in its nominal Subzone, is mentioned further below. The European Sub-Boreal zonation is applicable at zonal level more or less from East Greenland (except for the lowest Zone) via the Anglo-Norman and Rhodano-Swabian basins through Poland, central and southern Russia to the Caucasus and trans-Caspian Turkmenistan (Mangyshlak). It falls further south, however, because its faunas are there replaced by others. Alternative, parallel Standard zonations are needed.

(2) European Submediterranean zonation.

A Standard zonation of finesse comparable to the N European Standard has been put forward by Cariou (1980), based on the superbly developed, exposed and fossiliferous successions of W France, in Poitou and the Aquitaine Basin (figure l(b)). Correlation between the two Standard scales is very close at most levels, but two Problems remain. The first concerns the relative ranges of the Macrocephalus Zone. There is no evidence that the base of the Bullatus Subzone in Poitou coincides with the Macrocephalus Subzone. A precise correlation must await a fuller study of the Macrocephali tinae and Tulitidae and ther comparisons with those of Swabia (see below). In the author's opinion based on the evidence so far, the oldest Callovian found in Poitou is younger than that in England and in Swabia, the lowest parts having been lost in what is a well-recognized regional non-sequence that has also cut out much of the Upper Bathonian. The second problem concerns the top of the Callovian. The Callovian-Oxfordian boundary beds seem to be missing over wide areas in the Submediterranean Province; and even when present, their recognition must await a proper evaluation of the only ammonites likely to be diagnostic, the Perisphinctinae.

C. OTHER REGIONS

The zonation of the Callovian in other parts of the world ranges from the advanced to the rudimentary, for the usual reasons: frag= mentary faunal successions, sparse exposures, faunal provlncialism and insufficient study. There is space here only for some notes and comments.

(1) Western Europe: Swabia.

A most significant step towards the closer correlation of the Lower Callovian in its type successsions in England with those further afield has been taken by Dietl (1981), who has begun to re-examine, for the first time since Oppel, the classcial Macrocephalenoolith of Swabia. Contrary to the impresssion given by the literature, a clearly resolvable faunal succession is discernible. At least four ammonite horizons are present below the Calloviense Zone. The lowest (Sw1) is characterized by Kepplerites keppleri (Oppel), the next one up (Sw2) by Macrocephalites macrocephalus s.s. and Cadoceras quenstedti Spath. K. keppleri occurs in England at a level somewhere near the base of the Upper Cornbrash (Callomon 1959), i.e. a little above the base of the Macrocephalus Subzone and hence the Callovian by definition, and the keppleri horizon at the base of the Macrocephalenoolith of Swabia lies therefore very close to the base of the Callovian. The Macrocephalitids of the lowest two horizons there differ only to a minor degree, and hence there can be little doubt that the second horizon, with M. macrocephalus , also still lies within the Macrocephalus Subzone. Work on the Swabian faunas and successions continues. The area is also notable for the first undisputable records in Europe of true Macrocephalites from the Orbis Zone (olim Aspidoides Zone) of the Upper Bathonian.

(2) Portugal.

Without doubt one of the finest Bathonian-Callovian successions in the world is the one around Cap Mondego, but beyond a brief summary (Ruget-Perrot 1961, Rocha &t al. 1981) no account in the detail that it deserves appears yet to have been published. The natural sections are being obliterated by quarrying and a stratigraphical rescue Operation would seem to be a matter of urgency.

(3) Eastern Europe: USSR.

The zonations of the Callovian adopted in the USSR west of the Urals, from the Caucasus in the south to the Petshora in the north have recently been reviewed by Krymgolts et al. (1982). Those of the central and northern Russian Platform differ from the west European Sub-Boreal Standard mainly in the Lower Callovian, in which alternative Zones of Cadoceras elatmae and, in the north, Arcticoceras kochi are introduced. The Elatmae Zone is equated with the lower Calloviense Zone, but the close similarity between C. elatmae and C. quenstedti of Swabia (see above, horizon Sw2) suggests strongly an earlier age, equivalent at least in part to the Macro= cephalus Subzone. A detailed re-examination of the classical successions on the Oka around Elatma would seem a very worthwhile project. As for the Kochi Zone, the evidence in the Arctic is now overwhelming that its age lies somewhere near the Middle-Upper Bathonian boundary (see Callomon 1972, 1984a) ; and as Aroticoceras koehi (type from Greenland) is a junior synonym of A. ishmae (type from the Petshora), Ishmae Zone seems a more appropriate name.

(4) The Arctic.

At high latitudes, ammonites of the Macrocephalitinae and the Kosmoceratidae used in the Sub-Boreal zonation are absent or sporadic, so that another family, the Cardioceratidae, have to be used instead. These provide an almost uninterrupted evolutionary sequence from the Upper Bajocian to the Kimmeridgian (see Callomon 1984a), at present best known in East Greenland. Location of the Bathonian-Callovian boundary there again depends on the presence of Kepplerite. very close to, even if not quite identical with, K. keppler-i. The associated Cadoaeras apertum Callomon & Birkelund (in Callomon 1984a finds its closest matches in Cadoceras frearsi (d'Orbigny, 1845) of the Elatmae Zone of the Volga Basin. Near the top of the Callovian a fauna intermediate between Longaeviceras and Quenstedtoceras has been used as basis for a Subordinarium Zone in northern Siberia (Meledina 1977), but the forms are not identical with Quenstedtoceras subordinarium as defined by English type material, and may be a little older (see Callomon 1984a). The Lamberti Zone is also not recognizable, and is replaced by a Zone of Longaeviaeras keyserlingi.

Figure 1. - Standard zonations of the Callovian Stage. (A): drawn with Subzones equispaced. (B): drawn with faunal horizons I-XX equispaced (after Cariou, 1980). Approximate correlations (JHC) indicated by dashed lines.

(5) North America.

The ammonite faunas have recently been reviewed in detail (Callomon 1984b). They are mixtures of Boreal forms and a long succession marking yet another distinct faunal realm, the Eurycephalitinae of the East Pacific Realm. It transpires that most of the faunas previously thought to be Callovian are still Bathonian. Callovian is present in any quantity only in Alaska, and the Bathonian-Callovi; boundary is located yet again by Kepplerites very close to K. keppleri K. (olim Symourites) loganianus (Whiteaves).

(6) South America.

A revision of the long-known "Callovian" faunas of the Andes (Riccardi and Westermann, in progress) is going to call for reassignments, mostly downwards into the Bathonian, every bit as drastic as in North America. Most of the forms formerly assigned to Callovian Macrocephalitinae are also Pacific Eurycephalitinae, and many, even if not all, of the "Callovian" Reineckeiidae belong to another Pacific assemblage, the Neuqueniceratinae, whose age is in part also certainly still Bathonian and whose relations to the true, Tethyan Reineckeiinae remains unclear.

(7) The Indo-Malagasy Province.

The stratigraphically best-known successions are those of Cutch, but even so our knowledge is by European Standards still rudimentary. The best published summary is still that to be found in Arkell (1956; see also Krishna 1983). The richest and best part of the succession is in the Lower Callovian, but the apparently long ranges of some of the ammonites suggests that the sequence may not be as near to complete as its thickness might have led one to hope. Brief bursts of thick Sedimentation may turn out to have been separated by long non-sequences. A modern revision is urgently needed. Enormous new collections made in Madagascar, notably by Collignon (1958), have greatly amplified our knowledge of the faunas but have added very little to their stratigraphy. A problem of renewed interest is that of the position of the Bathonian-Callovian boundary in the region. There are growing reports of the overlapping of the ranges of the ammonite Clydoniceras (Bathonian) and Macrocephalites (Callovian par excellence). The earliest forms of the latter - M. triangularis -may turn out to be still of Bathonian age. At the top of the succession, the precise identification of the equivalents of the European Lamberti and Mariae Zones at the Callovian-Oxfordian boundary remains problematical, as it does almost everywhere south of the Tethys.

(8) Indonesia.

The rich faunas of the Sula Islands described by Boehm have been recollected by Westermann, Sato and Skwarko (1978). A description is nearly complete (Westermann and Callomon MS). Enough stratigraphical evidence was available to establish the main features of the successions and, above all, the faunal associations; and it is quite clear from the accessory elements such as Cadomites, Bullatimorphites and Oppelia that the earliest representatives of Macrocephalites are of early Upper Bathonian, perhaps even already Middle Bathonian age.

(9) Israel - Arabia.

The Jurassic rocks along the eastern borders of the Arabo-Nubian craton stretching in extensive outcrops from 20° to 35°N have so far yielded only intriguing glimpses of their faunas, which differ so strongly from those elsewhere that their interest is out of all proportion to their known volume. The Callovian is revealed by ammonites at a few horizons, particularly in the upper part, and the earlier descriptions, summarized by Arkell (1956) and based to a considerable degree on his own work (1952; see also Imlay 1970), have recently been amplified by new discoveries in Sinai and the Negev (Lewy 1983). New collections from Jebel Tuwaiq reported at the present Symposium by Enay and Mangold promise to add even more to our knowledge. These are exciting prospects.

D. CONCLUSION

As the foregoing notes indicate, much remains to be done in many parts of the world. The biostratigraphy of groups other than the ammonites has hardly been touched upon here, and some collective summaries in tabular form would be most welcome. They should also help to focus attention on unsolved problems and gaps in knowledge. The compilation of such summaries would be a worthwhile task for our Working-Group. Your co-ordinator welcomes contributions.

REFERENCES

ARKELL, W.J., 1952. Jurassic ammonites from Jebel Tuwaiq, Central Arabia. Phil. Trans. Roy. Soc. Lond., B 236: 257-313.

ARKELL, W.J., 1954. Three complete sections of the Cornbrash. Proc .Geol. Ass. , 65: 115-132.

ARKELL, W.J., 1956. Jurassic Geology of the World; Edinburgh & London, Olive & Boyd.

CALLOMON, J.H., 1959. The ammonite Zones of the Middle Jurassic beds of East Greenland. Geol. Mag. 96, 505-513.

CALLOMON, J.H., 1964. Notes on the Callovian and Oxfordian Stages. In: P.L. MAUBEUGE, ed., Comptes rendues et Memoires, Colloque Jurassique Luxembourg 1962, p. 269-291; Luxembourg, Inst. gd-ducal, sect. Sci. nat., phys., math.

CALLOMON, J.H., 1968. The Kellaways Beds and the Oxford Clay. In: P.C. SYLVESTER-BRADLEY & T.D. FORD, eds.; The Geology of the East Midlands, p. 264-290; Leicester, University Press.

CALLOMON, J.H., 1971. On the type species of Macrooephalites Zittel, 1884, and the type specimen of Ammonites macrocephalus Schlotheim, 1813. Palaeontology, 14, 114-130.

CALLOMON, J.H., 1972. Jurassic System. In: An annotated map of the Permian and Mesozoic formations of East Greenland. Meddr om Grønl., 168, no.3, 15-20.

CALLOMON, J.H., 1984a. The evolution of the Cardioceratidae (Jurassic ammonitina). Spec. Pap. Palaeontology, in press.

CALLOMON, J.H., 1984b. A review of the biostratigraphy of the post-Lower Bajocian ammonites of western and northern North America. Geol. Ass. Canada Speo. Pap., in press.

CARIOU, E., 1980. L'etage Callovien dans le centre-ouest de la France. These, Dr. Sci .nat. Univ. Poitiers, U. E. R. Sci. fond. appliquées, 325, 1. partie, 37p.

COLLIGNON, M., 1958. Atlas des fossiles characteristiques de Madagaskar. Fasc. iii: Bathonien-Callovien. Tananarive, Serv. geol.

DIETL, G., 1981. Über Macrocephalites (Ammonoidea) aus dem Aspidoides-Oolith und die Bathonium-Callovium-Grenzschichten der Zollernalb (SW-Deutschland). Stuttg. Beitr. Naturk., B 68, 15p.

DUFF, K.L., 1980. Callovian correlation chart. In: J.C.W. COPE, ed.: A correlation of Jurassic rocks in the British Isles, part 2: Middle and Upper Jurassic. Geol. Soc. Lond. Spec. Repts, 15_, 45-60.

IMLAY, R.W., 1970. Some Jurassic ammonites from central Saudi Arabia. U. S. Geol. Surv. Prof. Pap. 643-D, 17p.

NTERNATIONAL COMMISSION ON ZOOLOGICAL NOMENCLATURE, 1984. Opinion 1275: Macrocephalites Zittel, 1884, and Ammonites macrocephalus Schlotheim, 1813 (Mollusca, Cephalopoda): placed on the Official Lists. Bull. zool. Nomencl. , 41, 34-35.

KRISHNA, J., 1983. Callovian-Albian ammonoid stratigraphy and palaeobiogeography in the Indian Subcontinent with special reference to the Tethys Himalaya. Himal. Geol., 11, 43-72.

KRYMGOLTS, G. Ya., ed., 1982. The Jurassic Zones of the USSR. Trans.Interdeptl Strat. Comm. USSR, l 0 , 191p; Leningrad, Nauka. LEWY, Z., 1983. Upper Callovian ammonites and Middle Jurassic geological history of the Middle East. Bull. geol. Surv. Israel, 76_, 56p.

MELEDINA, S.V., 1977. Ammonites and zonal stratigraphy of the Callovian of Siberia. Trans. Acad. Sci. USSR, Siber. branch, 356, 228p.

ROCHA, R., MANUPPELLA, G., MOUTERDE, R., RUGET, Ch. & ZBYSZEWSKI, G. , 1981. Carta geológica de Portugal: notícia explicativa de folha 19-C, Figuera da Foz, 29-33; Lisbon, Serv. geol. Portugal.

RUGET-PERROT, Ch., 1961. Etudes stratigraphiques sur le Dogger et le Malm Inférieur du Portugal au nord du Tage. Mem. Serv. geol. Portugal, N. S., 7, 197p.

WESTERMANN, G.E.G., SATO, T. & SWARKO, S.K., 1978. Brief report on the Jurassic biostratigraphy of the Sula Islands, Indonesia, Newsl. Stratigr., 7_, 96-101.

REPORT OF THE BATHONIAN – CALLOVIAN BOUNDARY WORKING GROUP

By John H. CALLOMON, Convenor

ISJS NEWSLETTER 27/1: p. 33 (1999)

The Bathonian-Callovian Boundary Stratotype (Bat/Cal GSSP)

After the lengthy review of the state of progress so far given in the last Newsletter (no.26, January 1999), progress towards formal ratification has been limited. There are many competing calls on the time and resources available, but hope springs eternal and the beginning of a new century seems an appropriate target for final completion.

The restatement of the principles that should underlie standard chronostratigraphic taxonomy and nomenclature in the Phanerozoic has now been published in the volume of proceedings of the Vancouver Colloquium in August 1998 (CALLOMON & DIETL, 1999). One point raised in the last Circular could benefit from further response from our readers. It concerns the reconstituted membership of the Callovian Working Group. The call for reaffirmation of interest by the members of the Group of 1990, and of desire by new members to join, has elicited only a single response. We should like to hear from more of you, please. The path has now been further eased by your Convenor’s connection to the Internet. Note also that London telephone-numbers have changed yet again:

J.H.C.: University College London, 20 Gordon Street, London WC1H 0AJ UK tel: [44] 20 7504 4632; fax: [44] 20 7380 7463; <johncallomon@lineone.net>

Now would also be a good time to raise any further problems with or objections to the proposed choice of stratotype, at the base of the K. keppleri horizon at Albstadt-Pfeffingen.

Some news from the Front.

Interesting new sections across the Bathonian-Callovian boundary continue to emerge. Readers may recall that the standard succession of ammonite faunal horizons in the proposed boundary stratotype area of the central Swabian Alb is as follows:

Cal-III Cadoceras suevicum

II Cadoceras quenstedti

I Kepplerites keppleri

Bat-XVI Clydoniceras hochstetteri (= discus, variant?)

Of these, Cal-I-III fall into the Keppleri Subzone, the basal standard Subzone of the basal Herveyi Zone of the Callovian; and Bat-XVI is the highest horizon in the Discus Zone of the Upper Bathonian.

(1) The Swiss Jura.

A section has recently been described at Liesberg, 21 km SW of Basel (DIETL & GYGI, 1998). Horizon I could be clearly identified, yielding K. keppleri (typical); Macrocephalites verus, with fine examples of its microconch (M. hoyeri MÖNNIG); Kheraiceras bullatum; and Homoeoplanulites homoeomorphus [m] and H. (Parachoffatia) arisphinctoides, arkelli [M]. The bed appears however to lie disconformably on Upper Bathonian of uncertain age (Calcaire roux sableux).

Horizon II has long been known from an ammonite-bed at Anwil (BL), 11 km NW of Aarau, that has yielded a profusion of Macrocephalites verus (Basel Museum, described in part by THIERRY, 1978, p.212, pl.17, figs.1-6; another large collection by H. RIEBER in the University at Zürich); fairly common Cadoceras quenstedti; and another specimen of Cadomites altispinosus DIETL & HEROLD (1986). These records now extend the known occurrence of the lowest horizons in the Callovian across the whole of the Franco-Helvetic basin, from the borders of the Bohemian Massif (Sengenthal/Ofr.) into the Swiss Jura.

(2) Hildesheim, NW Germany.

The classical section in the brickworks at Temme have been carefully redescribed by MÖNNIG (1995). The Bathonian/Callovian boundary is marked by a condensed concretionary lag whose ammonites suggest however a relatively short time-span. They include Kheraiceras bullatum, Cadoceras suevicum (horizon III), Macrocephalites verus [M} and its [m], M. hoyeri sp.nov., the usual early Callovian perisphinctids and a single specimen of an undoubted Chamoussetia, Ch. menzeli sp.nov. Horizons I and II could not be identified. The highest Bathonian Discus Zone immediately below is however thick and richly fossiliferous.

(3) Western France: Poitou.

As is well known, the ammonite succession in Poitou is one of the richest and most detailed we have, following the stratigraphical studies over 30 years by E. CARIOU. The original series of 23 faunal horizons of 1980-1985 (I-XX, three subdivided into a,b) has grown to 32 (CARIOU in THIERRY et al. 1997). It forms the basis of the standard chronostratigraphy of the separate Submediterranean Province (6 Zones, 16 Subzones), made necessary by the bioprovincialism of its ammonites, which differ significantly from those of the Subboreal Province (7 Zones, 17 Subzones, ca. 40 faunal horizons, also summarized in THIERRY et al. 1997). The Subboreal succession was historically the first to be worked out and has therefore usually been taken to be the primary standard, but as the figures above indicate, there is now little to chose between the two zonations as regards finesse of time-resolution achieved.

Neither is there much difference in the areal extent over which the zonations can be applied, from Greenland across northern Europe as far as the Caucasus and Pamirs in the case of the Subboreal, and from Aquitaine and Lusitania via North Africa and the Balkans to the Elburz in the case of the Submediterranean.

There is sufficient bioprovincial overlap at many levels in the Callovian to make close correlations possible. But one problem that had long defied solution lies at the base of the Stage. It is therefore of direct relevance to this in terms of its basal boundary stratotype. The problem was that the lowest Callovian recognizable by means of ammonites in much of Poitou and the coastal sections of the Vendée seemed to lie above a non-sequence. At some localities the non-sequence could be positively identified, and various horizons (I-V) shown to lie directly with sharp lithological break on the Upper Bathonian, probably Retrocostatum Zone where datable. Nowhere could any evidence of the Discus Zone be found, in common with apparently many other areas in the Submediterranean Province, from the Ardèche to Cap Mondego. Even where the lowest Callovian beds were assigned to horizon I, the precise age could not be closely determined, for ammonites were sparse and not closely time-diagnostic. The best-known succession at Pamproux, for instance, commences with 3-4 m of limestones yielding sporadic Kheraiceras bullatum (hence horizon I, that of Kh. bullatum) and Macrocephalites spp., which, however, were younger than those of the Keppleri Subzone of Swabia. There was therefore no satisfactory definition of the base of the lowest Submediterranean Zone, the Bullatus Zone, and even less, a close correlation with the proposed base of the primary Subboreal Zone, the Herveyi Zone.

A new exposure has now resolved this problem. The section lies in a quarry nearBuffevent, ca. 3 km west of Niort. Dr CARIOU and I were kindly shown this section recently by M Patrick BRANGER (Cherveux, près de Niort). The lowest beds exposed are :

(1) Bathonian limestones, typical, seen 1-2 m; followed after a prominent plane parting by

(2) limestones, ca. 0.5 m, with occasional ammonites, including perisphinctids of the group of Homoeplanulites [M] and [m], Oxycerites spp., and Eohecticoceras biflexuosum (ORB.: ?topotypes);

(3) ammonite bed: limestones, 0.6 m, with a profusion of ammonites, including Homoeplanulites [m] / Parachoffatia [M] of the group of P. arisphinctoides (ARKELL), subbakeriae (ORB.); Macrocephalites verus BUCKMAN, typical, across its whole range of variability; Kheraiceras bullatum [M] and [m], typical; Oxycerites tilli LOCZY [M] and [m]; Paroxycerites subdiscus (ORB.: topotypes?); Phlycticeras cf./aff. dorsocavatum (QU.) (BRANGER coll.); and: Kepplerites keppleri (OPPEL)! (BRANGER coll.);

(4) and higher: limestones and marls, another 3 m, with Choffatia and Macrocephalites spp. The fauna of the ammonite bed, (3), is as near identical to that of the K. keppleri horizon of Swabia as could be expected over a distance of 700 km - yet another demonstration of the almost incredible power of ammonites as guide-fossils for time-correlations. Taking bed 3 as the basal horizon of the Bullatus Zone, the bases of the Bullatus and Herveyi Zones would coincide in age within the highest precision currently attainable by any available chronometer and the Callovian Stage would have a common base throughout the whole of the Subboreal and Submediterranean Provinces.

That leaves the intriguing question as to the age of bed (2): Discus Zone, or earlier? One begins to reflect more and more on MANGOLD’s suggestion (1990, p.97, fig.9) that the allegedly widespread absence of the Discus Zone is not in fact a lithostratigraphical gap but rather a biostratigraphical gap, the absence of the guide-fossils on which the recognition of the Discus Zone so often depends. And these are largely the species of the one genus, Clydoniceras. Those of the other associated groups, of perisphinctids and oppelids, tend to be rather long-ranging and are usually too sparsely represented or incompletely preserved to provide satisfactory alternatives as age-indicators. Could the Prohecticoceras angulicostatum Subzone in fact include the equivalents of the whole of the Discus Zone? A detailed study of the section at Buffevent might throw much light on this question.

(4) England.

The widespread presence of the K. keppleri horizon in the Cornbrash is attested by the collection of the index at numerous localities between Dorset and Oxford. It is however rare and seldom accompanied by any additional faunal elements. Most of the material is in museums and not closely assignable to recorded sections. What evidence there is suggests that the keppleri horizon lies at the base of the Upper Cornbrash, but this may not be invariably the case. The Cornbrash is now known to be chronologically so incomplete, made up of a mosaic of lenticular deposits, that it does not in any case contribute much to generalized chronostratigraphy around the Bathonian-Callovian boundary.

Things become more interesting higher up, in the Kellaways Beds, and a number of new finds are of note. One of these is the discovery of Cadoceras stupanchenkoi MITTA in the Lower Kellaways Clay (Cayton Clay Member), of Frome, Somerset, Herveyi Zone, Kamptus Subzone, top, horizon of Macrocephalites kamptus gamma. This species was recently described by MITTA (1998) from the region of Kostroma on the Russian Platform, where it marks a faunal

horizon placed at the base of the Gowerianus Zone, immediately above the top of the Zone of Cadoceras elatmae as drawn there. The base of the Gowerianus Zone in western Europe has been taken in recent years to lie in the first faunal horizon with Kepplerites (Gowericeras), that with K. (G.) toricellii, well characterized in the whole of the Franconian-Swabian Basin and in northern Germany. It has now also been found in England at two places: in a clay-pit in Kellaways Clay near Cirencester in Gloucestershire, and at the same locality as Cad. stupanchenkoi, at Frome. There it lies a little higher than the Cadoceras, on top of a thin laminated mass-flow sandstone called the Hengstridge Bed marking the change from Cayton Clay to Kellaways Sand.

Conclusions.

Many gaps remain to be filled in the ammonite biostratigraphy of the Callovian Stage, but the main framework of chronostratigraphic classification is becoming very firm and converging on what may be its final form.

References.

CALLOMON & DIETL, 1999. On the proposed basal boundary stratotype (GSSP) of the Middle Jurassic Callovian Stage. In: R.L. HALL & P.L. SMITH (eds), Advances in Jurassic Research 2000. GeoResearch Forum, 6: 41-54. Trans Tech Publications, Zürich.

DIETL, G. & GYGI, R. 1998. Die Basis des Callovian (Mittlerer Jura) bei Liesberg BL, Nordschweiz. Eclogae geologicae Helvetiae, 91: 247-260. Basel.

DIETL, G. & HEROLD, G. 1986. Erstfund von Cadomites (Ammonoidea) im Unter-Callovium (Mittl. Jura) von südwest-Deutschland. Stuttgarter Beiträge zur Naturkunde, B, 120: 9 p.

MANGOLD, C. 1990. Le Bathonien du Cap Mondego (N de Figuera da Foz, Portugal): biochronologie et correlations. Cahiers Université Catholique de Lyon, série Sciences, 4: 89-105. Lyon.

MITTA, V.V. & STARODUBTSEVA, I.A. 1998. [Field-work in 1998 and the Lower Callovian biostratigraphy ofthe Russian Platform]. VM-Novitates (Novosty iz Geologicheskogo Muzey Russkoe Akademiya Nauk), 2: 20 p. Moscow. (In Russian).

MÖNNIG, E. 1995. Der Macrocephalen Oolith von Hildesheim. Mitteilungen aus dem Roemer-Museum Hildesheim, neue Folge, Abhandlungen, 5: 77 p., 12 pls. Hildesheim.

THIERRY, J. 1978. Le genre Macrocephalites au Callovien inférieur (Ammonites, Jurassique moyen). Mémoires de l’Université de Dijon, 4: 491 p., 36 pls. Dijon.

THIERRY, J., CARIOU, E., ELMI, S., MANGOLD, C., MARCHAND, D. & RIOULT, M. 1997. 8. Callovien. In: Groupe français d’Études du Jurassique: Biostratigraphie du Jurassique ouest-Européen et Méditerranéen, zonations parallèles et distribution des invertébrés et microfossiles - E. CARIOU & P. HANTZPERGUE (eds), Bulletins du Centre de Recherches, Elf Exploration et Production, Mémoire 17:, 63-78. Pau.

CALLOVIAN WORKING GROUP

John CALLOMON, Convenor

ISJS NEWSLETTER 28: 8-10 (2001)

The Bathonian-Callovian boundary stratotype

There is little new to report. Formal submissions etc. will be made when time permits. The delay is perhaps regrettable, but it raises increasingly the question: the main features of the proposals having been published, most recently in the volume of proceedings of the Jurassic Symposium in Vancouver in 1998 (Callomon & Dietl 2000), what, other than completion of the formalities, remains to be done? What alternatives might or should be considered? Who dissents, on what grounds? What are the pros and cons that should be debated? Hence, what serious scientific project is or has been held up pending a final decision? The experience of the last 20 years (at least: some would say 37, or even 69) suggests that, administrative tidiness aside, very little: certainly nothing that is life threatening.

Nevertheless, it would be nice to hear from our colleagues, not only those in the Jurassic working primarily in the Bathonian-Callovian, but also anyone else more generally.

This especially so in view of the discussion of the principles of the whole exercise examined at Vancouver and published in the volume - principles that do not wholly coincide with those propounded in the ICS's Revised Guidelines (Remane et al., 1996), both in the points contained in them as well as in some important points that are not. Where better than in these pages to mount a debate? Does silence imply agreement, or moribundity, or pressure of more important things to be doing? There continues to be vociferous comment in extra-Mesozoic circles suggesting a rather different world view (see e.g. Aubry et al., 1998), to the point where the absence of a flood of ICS-ratified proposals to designate Stage [sic] GSSP's (two out of 11 in the Jurassic so far) is perceived as possibly an underlying conceptual problem, calling for remedial re-education. Jurassickers of the World, rally to the Flag: do we need reeducating?

News from the Front

It is with very great pleasure that we welcome the publication of a masterly survey of the stratigraphy of the Lower Callovian of the Russian Platform by Vasilii Mitta (2000). It reviews the localities, presents a chronostratigraphic framework down to Subzonal level (three standard Zones, five Subzones) and beyond, to the ultimate observable time-resolvable biozonal units, the biohorizons, here the faunal horizons of ammonites (17, compared with the current list of 18 in Britain, 14 in Germany, ca. 12 in France). The rich collections of ammonites are splendidly illustrated on 70 plates. All the classical names of the Russian Callovian going back to the times of Nikitin over a century ago have now been fleshed out, giving a much better impression of the diversity of the faunas and the relative importance, the biostratigraphy and hence the probable evolutionary biochronology, of its elements. Many forms familiar over a wide area of distribution, from the Arctic to the Caucasus but hitherto hardly described from Russia, are represented in strength, such as the Cadoceratinae and Kosmoceratidae. Old friends include the veritable Sigaloceras calloviense, so well known from its eponymous home at Kellaways, in Wiltshire.

Another is the great GSSP- messenger Kepplerites keppleri, already signaled on previous occasions. A splendid collection of it has been separately described by Mitta and Starodubtseva (2000) in another welcome new serial, VMNovitates, that bears an uncanny resemblance in format to AM-Novitates of New York; VM, here, stands for Vernadsky Museum, Moscow. This collection had been made by W.A. Stchirowsky in 1891-3 in the region of the river Sura, a tributary of the Middle Volga, and lain in the cellars of the museum ever since. (It illustrates a guiding principle much followed by the late James Edmonds, curator of the geological collections in the Oxford University Museum, that when the weather is too bad to do field-work outside, field-work in the cellars of the museum could be equally rewarding. Many were the types of old species thus rediscovered.)

Then there are some local specialities, leading among them a group based on Cadoceras subpatruum Nikitin, now separated under the new generic name Cadochamoussetia Mitta. It persists over a stratigraphical range in always the same restricted area, that of the Russian Platform, in which it is therefore typically endemic. Only a few examples have been found further afield; the rich collections from the Kellaways Beds in the English museums contain at most a handful. The genus Chamoussetia has a rather wider distribution, previously well known from East Greenland, England, and the Petshora; what appeared to be a curious gap in this distribution, in central Russia, is now also filled. But equally significant are the absences. Submediterranean elements such as Macrocephalites and the otherwise ubiquitous Perisphinctinae are rareties in the Lower Callovian. In this respect, the Russian Platform does not differ greatly from, e.g. England, and reflects a wellknown Subboreal bioprovincialism. But more puzzling perhaps is the rarity also of an otherwise very common Subboreal element, the genus Proplanulites: abundant in Britain and southern Poland, well known in East Greenland, western France and southern Germany, yet seemingly almost unknown in the Volga Basin. It is moreover a genus that appears suddenly in the succession and persists, yet has no plausibly identifiable ancestors. The Russian Platform provides therefore yet further examples of some of the residual mysteries in our understanding of ammonites: how did a lineage like Cadochamoussetia persist for a million years and yet remain so strongly coupled to such a relatively small area of marine habitat, one that had moreover unhindered access to much wider regions? Conversely, what kept Proplanulites out? And, as our biostratigraphical record and hence the fossil record becomes ever more complete, in cases such as the present as close to complete as it probably ever will be: why do these discontinuities in the record, both geographical and phylogenetic, seem to persist unchanged? We do not appear to be asymptotically converging on a final, continuous and complete description in even a group as abundant and time-diagnostic as Jurassic ammonites. What are they trying to tell us about habitat, ecology, ontogeny and hence phylogeny, Darwinian or otherwise?

References

AUBRY, M.-P., BERGGREN, W.A., VAN COUVERING, J.A. & STEININGER, F. 1999. Problems in chronostratigraphy: stages, series, unit and boundary stratotypes, global stratotype section and point and tarnished golden spikes. Earth-Science Reviews, 46: 99-148.

CALLOMON, J.H. & DIETL, G. 2000. On the proposed basal boundary stratotype (GSSP) of the Middle Jurassic Callovian Stage. In: R.L. HALL and P.L. SMITH (eds): Advances in Jurassic Research. GeoResearch Forum 6: 41-54.

MITTA, V.V. 2000. Ammonites and biostratigraphy of the Lower Callovian of the Russian Platform [in Russian]. Bulletin of CF VNIGNI, Moscow, 3: 144p., pls.1-70. MITTA, V.V. & STARODUBTSEVA, I.A. 2000. W.A. Stchirowsky and the study of the Mesozoic in the Alatyr-Kurmysh area (basin of the Middle Volga) [in Russian]. Vernadsky-Museum Novitates, 5: 20 p., pls.1-4.

REMANE, J., BASSETT, M.G., COWIE, J.W., GOHRBAND, K.H., LANE, H.R., MICHELSEN, O. & WANG NAIWEN. 1996. Revised guidelines for the establishment of global chronostratigraphic standards by the International Commission on Stratigraphy (ICS). Episodes, 19: 77-81.

CALLOVIAN WORKING GROUP

John CALLOMON, Convenor

ISJS NEWSLETTER 29: 10-11 (June 2002)

Since the last Newsletter there is little formal business concerning the Bathonian-Callovian Boundary Stratotype to report. There continues to be progress, however, in thebiostratigraphical exploration of these Stages, some of it sensational. The latest news comes once again from our colleagues in Russia.

Some of our readers may recall that one of the outstanding unsolved problems in the Middle Jurassic was the correlation of two of the major standard chronostratigraphical zonations based on ammonites: the primary standard used in most of Europe and the western Tethys (the ‘Tethyan’ or ‘Submediterranean’ Provinces in common parlance); and the Boreal secondary standard used in the circum-Arctic shelf deposits of Eurasia and North America, previously loosely referred to as the Boreal Bathonian. The latter, based overwhelmingly on the ammonite biostratigraphy of East Greenland, is as refined as the former - if not even more so - in terms of the temporal resolution of its zonal units. The last comprehensive review (CALLOMON 1993) lists a succession of nine Zones below the base of the Callovian, starting with the Borealis Zone (index ranocephalites borealis (SPATH)) and rising via the Ishmae Zone (index Arcticoceras ishmae (KEYSERLING)) to the Apertum Zone (index Cadoceras apertum CALL. & BIRKELUND), which probably spans the Bathonian- Callovian boundary. These nine Zones encompassed a biostratigraphy resolved into 25 ammonite faunal horizons.

There were two problems.

Firstly, the lowest, Borealis Zone, lay everywhere in the Arctic above an ammonite biostratigraphic non-sequence. In Eurasia, the youngest faunas found below it were of Toarcian or oldest Aalenian ages (Opalinum Zone in Svalbard); in Arctic Canada, of earliest Bajocian age (Sauzei Zone, Arkelloceras tozeri). The Borealis Zone could therefore be still a lateral equivalent of the Bajocian, at some level from the Humphriesianum Zone upwards.

Secondly, the ammonites of the Boreal Bathonian were totally different from those of classical peri-Tethyan Europe. No areas of faunal overlap were known, so that correlation at zonal level of the primary standard Bathonian with the Boreal Bathonian was quite impossible. This case of mutually exclusive faunal provincialism was if anything even more serious and extensive than that in the famous Tithonian/Volgian/Portlandian example around the Jurassic- Cretaceous boundary.

At least partial solutions of these problems are now in sight. In the first, the ‘age’ of the Borealis Zone, there had been some previous indications, based on taxonomic affinities of the ammonites, that C. borealis was closely related by descent from NE Pacific species of Chondroceras, of Humphriesianum Zone age, i.e. latest Early Bajocian. An age of around the Early-Late Bajocian boundary has recently been confirmed by a physical technique, on the basis of the strontium Sr(87/86) isotope-ratios found in calcitic belemnites (M. ENGKILDE, Copenhagen, to be published).

News now comes of progress with the second problem. Until about ten years ago, the furthest south that Boreal Bathonian ammonites had been recorded in Eurasia had been in the Petshora basin, west of the northern Urals, the typearea of Arcticoceras ishmae itself. Renewed field-work by D.B. Gulyaev, D.N. Kiselev and V.V.Mitta in the Volga Basin has yielded rich and varied new collections from hitherto unexplored localities, especially in the region of the Middle Volga, along its northern tributary the R. Unzha, between Kostroma and Nizhniy Novgorod. (For more readily accessible descriptions, see D.B GULYAEV & D.N. KISELEV 1999, D.B. GULYAEV 2000, references below; the extensive review by V.V. MITTA was already cited in the previous Newsletter, no.28. A new review of the Middle Callovian has also appeared: KISELEV 2001). They include Cadoceras infimum GULYAEV & KISELEV, index of the highest, new Infimum Zone below the Callovian Elatmae Zone in a revised standard zonation, and Kepplerites svalbardensis SOKOLOV & BODYLEVSKY, types from Spitsbergen. Both are close to or identical with forms from the lower Calyx Zone of Jameson Land and Store Koldewey in East Greenland and undoubtedly of Upper Bathonian age. The rich new collections from the rest of the Lower-Middle Callovian, including the true Kepp. keppleri, were also referred to previously.

Now comes news from Saratov, on the Lower Volga, 51°N (the same as London), 700 km SE of Moscow. Vasilii MITTA permits me to pass on the following:

V.V. MITTA & V.B.SELTZER, 2002. First finds of Arctocephalitinae (Ammonoidea) in the Jurassic of the south-eastern Russian Platform, and the correlation of the Boreal Bathonian Stage with the standard scale. Bulletin CF VNIGNI, Moscow, 7, in press.

The paper describes ammonites of the boreal subfamily Arcticoceratinae (Middle Jurassic, Cardioceratidae) that have been found for the first time in the south-eastern part of the Russian Platform, in a section in the vicinity of Saratov, in association with representatives of the “Tethyan” family Parkinsoniidae. Beds with Oraniceras besnosovi sp.nov. [closely related to Oraniceras gyrumbilicum (QUENSTEDT), [M] of Parkinsonia wuerttembergica (OPPEL)[m] - JHC] are overlain by beds with Arcticoceras harlandi RAWSON [found in Greenland and Svalbard in the lower part of the Ishmae Zone - JHC] and, higher, A. ishmae (KEYSERLING) itself. Also found, but not in situ, were some Arctocephalites spp.

The new discoveries allow us to correlate the Ishmae Zone of the Boreal Bathonian with a part [the highest - JHC] of the Lower Bathonian of the standard scale, and to see palaeogeographical and palaeobiogeographical relationships in the Bathonian in a new light.

So, the Ishmae Zone turns out to be equivalent to the highest part of the Lower Bathonian in Europe, where Parkinsonia (Oraniceras) gyrumbilica/wuertembergica occurs in the highest, Macrescens Subzone of the Zigzag Zone. In Greenland, new discoveries in 1996 have increased also the number of faunal horizons now discernible in the Boreal Bathonian olim, to a total of 50. The number recognized in classical Europe over the same interval, from basal Upper Bajocian to basal Callovian, stands at about 32.

References:

J.H. CALLOMON, 1993. The ammonite succession in the Middle Jurassic of East Greenland. Bulletin of the Geological Society of Denmark, 40: 83-113.

D.B. GULYAEV, 2001. Infrazonal ammonite scale for the Upper Bathonian - Lower Callovian of central Russia. Stratigraphy and Geological Correlation, 9: 65-92.

Moscow. [Cover-to-cover translation by MAIK of the journal in the original Russian edition].

D.B. GULYAEV & D.N. KISELEV, 1999. Boreal’niy morskoy verkhniy Bat srednego Povolzh’ya (ammonity I stratigrafiya) [Boreal Upper Bathonian in the middle reaches of the Volga River (ammonites and stratigraphy)]. Stratigrafiya, Geologicheskaya Korrelyatsiya, 7: 79-94.

D.N.KISELEV, 2001. Zones, Subzones and biohorizons of the Middle Callovian of central Russia - stratigraphy and paleontology. Pedagogical University of Yaroslavl,Natural-Geographical Faculty Publications, Special Paper 1, 38 p., 10 pls.

CALLOVIAN WORKING GROUP

John CALLOMON, Convenor

ISJS NEWSLETTER 30: 16 (2003)

Since the last Newsletter there is once more little formal business to report concerning the Bathonian- Callovian Boundary Stratotype. Hope continues to sustain the plan to see the formal proposals prepared for submission in the coming year. It has also been a quiet year on the Callovian front elsewhere. This reflects the maturity of our state of knowledge of the Stage and, it has to be recognized, a shrinking band of those with the interest, time and resources to be active in it. The unsurpassed Colloquium on the Jurassic organized by our Italian colleagues at Palermo provided once again an opportunity to meet old friends from all over the world and to discuss problems in the Callovian as in the other Stages, but nothing of great import requiring urgent attention seemed to emerge. One of the many surprises was to be presented with copies of two superb volumes reprinting and revising the immortal contributions of Gaetano Gemmellaro. Callovian examples, though perhaps modest in numbers, include key elements fundamental in modern revisions world-wide.

There continues to be progress here and there at the local level. I can report only one example frompersonal experience. It concerns parts of the Kellaways Beds in the Lower Callovian. These are rarely seen in Britain, being developed largely in soft, recessive facies, so that there are almost no natural outcrops other than on the Yorkshire coast. They do, however, underlie wide tracts of river gravels in the basins of the upper reaches of the Thames, south of Cirencester in Gloucestershire. These gravels are intensivelyexploited, in part for the usual purposes of filler for concrete but, being composed largely of limestone derived by erosion of the Cotswolds, they find a particular use ground up as base for making cast building-blocks for housing in artificial Cotswold Stone. Drainage ditches expose the Kellaways Beds and although the sections thus opened are very shallow, they are exposed over large areas. This provides ideal conditions for collecting rich assemblages from very narrow stratigraphical intervals, i.e. for the characterisation of faunal horizons. As a result, two new biohorizons of ammonites have been discovered in the vicinity of the village of Ashton Keynes. The first lies above that of Kepplerites galilaei and is characterised by forms that retain the size and rounded whorl-section of K. galilaei but have already the involute coiling and fine, dense ribbing of Sigaloceras. The galilaei horizon labelled XIII in the volume of the Lisbon Colloquium (1989) has therefore to be replaced by two: XIIIa and XIIIb. The second lies a little higher still and yields forms now unmistakably assignable to Sigaloceras, but having tabulate, flattened venters, only on the phragmocone. This is followed by a level of the true Sigaloceras calloviense, formerly XIV, now the higher of XIVa, XIVb. Finally, the most fossiliferous level of them all, that of Sigaloceras micans, XV. All these horizons span a thickness of strata barely more than two metres. I was particularly pleased to find confirmation of the distinctness of the levels of Sig. calloviense s.s. - always rare - and Sig. micans, found in profusion. To it belong most of the specimens figured in the literature. And so it goes on: Buckman would have felt pleased.

CALLOVIAN WORKING GROUP

John Callomon, CONVENOR

ISJS NEWSLETTER 31: 8-9 (2004)

There is little new to report on the Callovian. Efforts continue to sharpen the correlations between the western European, Russian and East Greenland successions, largely on the basis of the most sensitively time-diagnostic ammonites, those of the genus Kepplerites. It seems increasingly likely that the Bathonian–Callovian boundary lies a little higher in East Greenland than assumed hitherto. Otherwise, it is pleasing to see the first modern description of the Bathonian-Callovian succession in the Boulonnais by Jacques THIERRY. There are pictures of many old friends. The Discus Zone of the Upper Bathonian is well represented by Clydoniceras and the Koenigi–Calloviense Zones of the Lower Callovian by Cadoceras, Proplanulites, Kepplerites and Sigaloceras. But the basal Herveyi Zone can be only sketchily recognized and then mainly by brachiopods, like the Upper Cornbrash in England. The biofacies as a whole puts the Callovian of the Boulonnais firmly in the Normanno-British Subboreal camp: barely a sniff of the Med.

Reference:

THIERRY, J. 2003. Les ammonites du Bathonien-Callovien du Boulonnais: biodiversité, biostratigraphie et biogéographie. Geobios, 36: 93-126.

CALLOVIAN WORKING GROUP

John CALLOMON, Convenor

NEWSLETTER 32: 14-16 (2005)

There is not much new to report since last year. Writing up the formal proposal is still in progress, and for those many of you who find that they cannot meanwhile get on with anything else pending the final ratification of the PSSP (Primary Stratotype Section and Point) by the ICS, the good news is that the proposals have not been changed since they were set out in the volume of proceedings of the meeting in Vancouver in 1998 (Callomon & Dietl, 2000). Nothing stratigraphical has happened since to give cause to modify the proposals in any way - at least, nothing that has come to my notice. The BathonianISJS Callovian boundary lies at the base of the Kepplerites keppleri biohorizon in its type-area around Albstadt- Peffingen, in Hohenzollern Swabia, formally in a type-section excavated for the purpose in a naturereserve in the Roschbachtal, 1 km west of the centre of Pfeffingen.

There are just three points. First, the type-locality of the species Kepplerites keppleri lies at the Achalm, a hill near Eningen, 5 km east of Reutlingen, whereas the type-locality of the biohorizon of K. keppleri lies in Albstadt-Pfeffingen, 35 km to the south-west. There is good material from Eningen in the collections, including the type of K. keppleri in Munich, but we have no detailed description of a section in which the material can be located. At Pfeffingen there are large collections from very precisely located horizons (Callomon & Dietl, fig.3a, beds 5, 6a). The question arises whether the levels with Kepplerites at Eningen and Pfeffingen are truly of precisely same age, at the level of time-resolution now generally attainable in the Jurassic by means of ammonites: whether the assemblages of specimens from the two localities are indistinguishable or not, whether the type of the index came in fact from its eponymous faunal horizon. At first glance, the faunal assemblages appeared to be the same. On closer examination, there seemed to be slight differences: theforms from Pfeffingen seemed to be less strongly sculptured. But finally, after comparing enough material from Eningen (in Munich, Stuttgart, Tübingen, Paris and London) with the large collections from Pfeffingen (Stuttgart) the conclusion is firmly that they are the same. The differences are apparent, due to differences in preservation. The material from Pfeffingen, from hard stone, consists mostly of internal casts without test. The specimens from Eningen, from softer beds, have the test preserved. The last possible doubts about the geographical extent and the unique age at its typelocality of the keppleri horizon are therefore finallydispelled.

Second, further exploration of the Middle Jurassic on the Russian Platform by Vasili Mitta and other colleagues continues to turn up more and more new faunal horizons of undoubted pre-Callovian age. The myth of the Great Worldwide Bathonian Regression is being finally laid to rest even in the region in which it had always been regarded as most firmly demonstrated. The new discoveries contain elements that link up with both western Europe and East Greenland. It seems in consequence that the Bathonian-Callovian boundary in the Boreal SSSP (Secondary Stratotype Section and Point) in Jameson Land (see Callomon 1993) may have been drawn a little too low. The Boreal Bathonian there was even more extensive than previously thought. We await Vasili’s descriptions with great interest.

Some previously unpublished sections across the Boreal Bathonian-Callovian boundary in East Greenland have recently been described. The first two lie in central Jameson Land at Fossilbjerget (71°N), aptly so named by Nordenskjoeld in 1900, nos. 42, 43 in Callomon (1993), and show probably the best developed ammonite biostratigraphy across the boundary in Greenland (Callomon, 2005). They are therefore the natural candidates for a boundary stratotype (SSSP) in the Boreal secondary standard zonation. The precise level has still to be decided. A third succession to have yielded a good ammonite and dinoflagellate biostratigraphy lies far to the north, on the quasi-littoral relict sediments preserved on the east coast of Store Koldewey (76°N) (Piasecki et al., 2005).

Third, a more general point relating to magnetostratigraphy. The type section at Pfeffingen was sampled for remanent palaeomagnetism in 1997 by J.G. Ogg and G. Dietl. The lithologies are iron-rich, argillaceous and limonite-oolitic. The succession of events leading to their present state is (a) slow, probably highly discontinuous - ‘condensed’ - sedimentation; (b) large-scale, coarse bioturbation by burrowers such as those forming Thalassinoides, destroying all primary sedimentary structures and concentrating the iron ooliths into typical pockets or clouds; (c) fairly early diagenetic concretionary induration through mobilisation of cements, now sideritic or pyritic, forming well-differentiated, very hard beds with undulating, nodular boundaries or scattered concretions in softer shales, preserving their contained fossils from crushing and other forms of distortion by (d), subsequent dewatering and compaction. Thus, the ammonites in the hard beds and concretions have hollow phragmocones partially filled with sparry calcite or other minerals, while those in the non-indurated, shaly, softer beds are crushed flat. Although now shaly, perhaps somewhat laminated, these softer beds were at the time just as burrowed and bioturbated as the hard beds in which the bioturbational structures can still be observed.

The determinations of remanent magnetism were experimentally successful and sufficient to give clear indication of N/R polarity at numerous levels in the parts of the section covered, beds 2 to 7 (downwards) in Fig. 3a of Callomon & Dietl (2000, p.48), together 1.2 m thick. Beds 4-6a (0.6 m) span the two lowest ammonite faunal horizons of the Callovian, the keppleri and quenstedti horizons of the Keppleri Subzone of the Herveyi Zone. The Bathonian- Callovian boundary lies between beds 6a and 6b. The magnetic signals then appear to indicate clearly that even within the single beds 6a (0.15 m) and 4 (0.4 m) there were several polarity-reversals: N in the lower part, R in the upper part, of bed 6a, keppleri horizon; N in the lower part, then several of both N and R in the higher parts, of bed 4, quenstedti horizon. But even if the lithological record of the time-spans involved is highly incomplete, which may well be the case, and there really had been such a rapidity of polarityreversals, the fact remains that any original sedimentary time-proxy in the form of sedimentary layering within a bed, factor (a) above, was completely destroyed by the subsequent bioturbation, (b). Yet it is the geomagnetic imprint at stage (a) that is supposed to be significant. So what is it that is being measured? And what significance does it have, if any? Could it be the crystallisation of step (c)? I have been unable to obtain answers to these questions. Can someone help?

References

Callomon, J.H. 1993. The ammonite succession in the Middle Jurassic of East Greenland. Bulletin of the Geological Society of Denmark, 40, 83-115.

Callomon, J.H. 2005. Description of a new species of ammonite, Kepplerites tenuifasciculatus n.sp., from the Middle Jurassic, Lower Callovian of East Greenland. Appendix to Alsen, P. and Surlyk, F. Maximum Middle Jurassic transgression in East Greenland: evidence from new ammonite finds, Bjørnedal, Traill Ø. Geological Survey of Denmark and Greenland Bulletin 5, 42-49.

Callomon, J.H. & Dietl, G. 2000. On the proposed basal boundary stratotype(GSSP) of the Middle Jurassic Callovian Stage. In: Hall, R.L. & Smith, P.L. (eds), Advances in Jurassic Research 2000, 41-54. Trans Tech Publications, CH-Zürich.

Piasecki, S., Callomon, J.H. & Stemmerik, L. Jurassic dinoflagellate cyst stratigraphy of Store Koldewey, North-East Greenland. Geological Survey of Denmark and Greenland Bulletin 5, 99-112.

CALLOVIAN WORKING GROUP

John CALLOMON, Convenor

ISJS Newsletter 33 – 16 (2006)

As far as a proposal for a Callovian GSSP is concerned, nothing has substantially changed in the one put forward at the Vancouver Symposium (Callomon & Dietl 1998, published 2000). It remains only to supplement it with some details relating to secondary standards, either bioprovincial when based on ammonites or otherwise when not, and pointers to some reference sections traversing the Bathonian-Callovian boundary that might illustrate some particular bio- or other stratigraphical character better than what is to be seen at the type sections. There have been no comments since Vancouver from any quarter, for or against the proposals put forward there, and I shall therefore take these as the basis for an updated version written with the Voting Members, etc., of ISJS in mind as the primary readers.

Reference:

CALLOMON, J.H. & DIETL, G. 2000. On the proposed Basal Boundary Stratotype (GSSP) of the Middle Jurrassic Callovian Stage. In: HALL, A.R. & SMITH, P.L. (eds), Advances in Jurassic Research 2000, GeoResearch Forum, 6, 41-53. Trans Tech Publications, Zürich.

Callovian Working Group

John CALLOMON and Gerd DIETL, Convenors

ISJS NEWSLETTER 34/2: 14-16 (2007)

It is our firm resolve formally to complete the proposal and procedures for ratification by the ICS of the GSSP for the base of the Callovian Stage this year. It is a matter of regret that it should have taken so long, but some of the reasons (and excuses) may become apparent from what follows.

Historical. In short, the scientific arguments were completed in 1990 and a unanimous decision was reached by a properly constituted Working Group at a meeting called for this purpose in Stuttgart. This was in the days of the ICS Guidelines Version I (1986) and to satisfy their requirements in full would have called for considerable extra time and effort, for little apparent scientific gain - at least, in the eyes of the Working Group. There seemed to be no great problems elsewhere awaiting a formal declaration of a Callovian Stage GSSP, no uncertainties dependent on it clamouring for a decision. The reason was simple. The chronostratigraphical level chosen for the base of the Callovian was little changed from where it had been since Oppel’s time over a century before and where everyone had always taken it to be. We in the Jurassic seemed to be getting along very well without Stage GSSPs as conceived and demanded by the ICS, again for reasons well understood in the Jurassic community but, it seems, less so by the members of the ICS. There tended hence to be always other things more urgently in need of attention. The history of events was as follows.

(1) Stuttgart 1990. - The deliberations and decisions reached at the meeting of the Callovian Working-Group held at Stuttgart and the proposed type section across the Bathonian-Callovian Boundary near Albstatt-Pfeffingen in the Swabian Alb were described quite fully in a Report circulated among the members of the WG and available on request. A summary of the meeting, its proceedings and the decision reached was published in ISJS Newsletter 20 (Callomon 1991, p.5). The stratotype section was chosen to lie in a section near Albstadt-Pfeffingen. The boundary was chosen on the basis of the biostratigraphy of the ammonite family Kosmoceratidae, whose widespread distribution and rapid evolution makes possible geological time-correlations at this level over distances with a precision having no rivals. Such correlation-potential was taken to be the factor of dominant importance. Additional constraints required the boundary to lie at the base of the standard chronostratigraphical hierarchy of subdivisions, that of the lowest Subzone of the lowest Zone of the Stage – a concept also traditional in the Jurassic since Oppel (and finding no mention in the Guidelines). The level finally adopted was the base of a thin bed marking the biohorizon of Kepplerites keppleri at the base of the Keppleri Subzone of the Herveyi Zone of the Callovian Stage. The scientific basis for these choices had been presented in some detail in the Proceedings of the 2^nd Colloquium on the Jurassic held in Lisbon in 1987 (Callomon, Dietl & Page 1989). All the scientific evidence was therefore publicly available. These principles were well understood by all 18 members of the Working-Group, representatives of 11 countries. They also understood ammonites and their biostratigraphy as well as the correlation-potentials of other guide-fossils often used for time-correlations. No alternatives of comparable correlation-potential could be discerned and no alternative sections of comparable merit for the GSSP were proposed. The vote to adopt the proposals put forward at Stuttgart was unanimous, with no abstentions. No challenge on scientific grounds has ever been raised, either then or at any time since. An objection was however raised on doctrinal grounds by a colleague (not a member of the Callovian WG) who protested that the proposal did not meet one of the critical requirements of the Guidelines (of 1986), namely that the stratotype should be chosen in a section that was “complete” and not “condensed”. Neither he nor the Guidelines explained what is meant by these terms, nor by what criteria one could assess them in any particular case. To judge from an example of uncondensed completeness that he cited as a guide, that of a section in the Lower Lias of northern Germany, one could only assume a rather naïve faith on his part in the intrinsically more ‘complete’ nature of successions in clay-facies compared with those in limonite-oolitic claystones. That definition of ‘completeness’ is critical. Any discussion of it is meaningless until a time-scale has been specified. This had already been clearly spelt out well before 1986 in two classical papers by Schindel (1980, 1982), of which at least the ICS should have been aware, and amplified by another by Sadler & Strauss (1990). A resolution analysis of some prototypical Jurassic successions was subsequently carried out by one of us (Callomon 1995) and the results were revealing - and highly relevant to the argument. The time-scale of relevance here is that of the precision of time-correlations across distances by means of the best clocks available, here the ammonites as guidefossils. It is the time-interval between distinguishable ammonite biohorizons, of the order in the Jurassic of 100 ka. On this time-scale the succession across the Bathonian-Callovian at Pfeffingen is complete, as the extensive researches of the 1980s in Britain and Germany had gone to considerable trouble to show. Events on shorter time-scales, such as those of taphonomy or sedimentary parasequences are irrelevant for they have little correlation-potential. This objection against the 1990 proposals was submitted directly to the (then) Chairman of the ISJS - not to the Convenors of the WG, who found out about it and what it was only indirectly. It did not take long to submit a counter-argument, but to little effect. The Convenors of the WG were informed by the ISJS (Newsletter 24, 1997, p.7) that the proposals adopted at Stuttgart were not acceptable, as not meeting the ICS requirements, and that the case would have to be reopened. (And this, despite the fact that the Stuttgart proposals not yet been ever formally submitted to the ISJS in the first place. A sudden loss of urgency is then perhaps understandable. More details of this episode are to be found in Callomon & Dietl (2000 – Vancouver volume, p.49).

(2) Vancouver 1998. - The proposals were revived and presented at the 5th Jurassic Colloquium in Vancouver in 1998, published in the volume of its proceedings (Callomon & Dietl, 2000). The arguments of 1990 remained essentially unchanged but were amplified somewhat in the light of developments during the previous decade. The basic principles, P1 – P5, of chronostratigraphy were spelt out yet again and the extent to which the now revised Guidelines, Version II (1996) matched them was discussed. In particular, the concepts of parallel primary and secondary standards – all of them global - were explicitly re-emphasized (going back to the 1sst Jurassic Colloquium at Erlangen in 1984, Callomonn 1985). The auxiliary reference sections espoused by the ICS are not the same thing. They are meant to amplify the stratigraphy of the succession around a standard boundary stratotype, of the beds below and above, not to provide alternatives to the standard, nor to provide lternative expressions of the Stage as a whole. Primary and secondary in contrast refer to alternative parallel standards, the defining boundaries of each of which could then themselves be amplified by means of auxiliary reference sections. The account at Vancouver now also presented the preliminary results of a palaeogeomagnetic survey of the succession at Pfeffingen, based on measurements by Jim R. Ogg (Purdue), and of measurements of the strontium stable isotope-ratio in the region of the Bathonian-Callovian boundary (but not at Pfeffingen) as reported by John M. McArthur (London). There the arguments rest today. Nothing to our knowledge of scientific significance has happened since that calls for any substantive changes. The account of 1998 at Vancouver did raise a new crop of objections - this time by the then Chairman of ICS himself, acting as reviewer of the manuscript of the paper prior to publication in the Proceedings. They led to some correspondence that it would perhaps now be unkind to revive. It revealed that he did not understand the hierarchical, tiered structure of our standard chronostratigraphical classification in general; how it is built up from the biostratigraphical characteristics of our chosen guide-fossils, the ammonites, in our primary standard chronostratigraphy in particular; and how the keys to such hierarchical classifications lie in their members at the lowest level in the hierarchy - not at some arbitrarily chosen higher level such as Stages. Even more strangely, he did not seem to see how the same principles apply in the analogous system of Linnéan classification used in zoological taxonomy, drawn in for comparison: that the scope of a genus was completely defined by the species it contained. In the event, the manuscript appeared in print unchanged.

The present. If there have been no calls for change in the boundary definition of the primary Subboreal Callovian standard itself, there have been interesting developments elsewhere arising in part from new fieldwork in regions in which the segregated bioprovincialism of the ammonites have made it necessary to set up independent secondary standard chronozonations. A recent comparative review of the standard chronozonations of the Middle Jurassic in the Boreal, Subboreal and Submediterranean Provinces of Europe may be found in Callomon (2003a):

(1) The Submediterranean Province. This was the first faunal province to be given an independent chronozonation in the Callovian, going back to the studies in western France by Cariou in the 1980s. His classification was found to be more widely applicable in regions with well-developed Callovian successions, in the Paris and Rhone Basins, Spain and Portugal. Correlation with the primary Subboreal standard was moderately satisfactory at most levels except at the base, which is marked by widespread disconformities or biostratigraphic gaps. The relation between the base of the Submediterranean and Subboreal Callovian Stages was therefore highly uncertain. This problem has now been solved by the discovery of a previously undescribed section near Niort, western France, through a fault bounded synsedimentary trench showing a more complete succession, one bed in which has yielded Kepplerites keppleri (Balusseau, Branger & Cariou, to be described). The two standard Stages can therefore be given the same basal boundary and the same GSSP can serve to define both.

(2) The Russian Platform. - There has been a remarkable resurgence in activity in the Jurassic of the Russian Platform, and in the Volga Basin in particular, by our colleagues D.B. Gulyav, D.N. Kiselev, V.V. Mitta and M.A. Rogov. As we all know, a generation ago there was officially no marine Bathonian on the Russian Platform. The oldest post-Palaeozoic sediments were declared to be Callovian, beginning with the Zone of Cadoceras elatmae. Now, suddenly, pre-Callovian sediments with ammonites are being found all over the region. The closest affinities of most of these ammonites, moreover, are with those of the Arctic, as exemplified by those of East Greenland in particular. Typical Arcticoceras (sic) has been followed south as far as Saratov, which lies (today) at the same latitude as Kellaways in Wiltshire. Prominent among the faunas are the Kosmoceratidae - including at one level the undoubted Kepplerites keppleri. Rarely has the discovery of one guide-fossil drawn such a decisive line across a stratigraphic succession. The ammonites above the keppleri horizon differ sufficiently from those of western Europe to justify the construction of another independent, Russian secondary standard chronozonation and this is in progress. However, this can also share its base with that of the primary standard, at the horizon of Kepplerites keppleri.

(3) East Greenland. The firm recognition of a long pre-Callovian succession of ammonite faunas in East Greenland goes back to 1959. A review of the state of knowledge some 30 years later (Callomon 1993) gave a list of 37 ammonite biohorizons below the top of the Callovian, of which at least the first 25 were of pre-Callovian age. None of these could be directly correlated with the primary standard NW European succession, least of all the lowest of them, that of Cranocephalites borealis. They were therefore made the basis of another independent secondary zonation collectively referred to as simply Boreal Bathonian. The borealis horizon has since been dated by roundabout faunal correlations and strontium isotope ratios in belemnites to lie at about the Lower-Upper Bajocian boundary. The position of the Bajocian-Bathonian boundary in East Greenland remains conjectural. The succession over the range of faunas 18-35 is rich in Kosmoceratidae and these were therefore drawn on in attempts to locate the Bathonian-Callovian boundary. However, the study of the ammonites was preliminary and the most likely correlation seemed to be between fauna 26, that of Kepp. traillensis Donovan, and Kepp. keppleri. More recent studies by Vassily Mitta, aided by the new discoveries in Russia, suggest however that the correlation should lie slightly higher, at faunal horizon 30. Unfortunately, the quality of the material from Greenland at this level is poor, but a re-examination by one of us (JHC) supports Mitta’s contention.

(4) Other provinces. Secondary standard zonations of varying qualities, depending on the circumstances, have been proposed also for other regions, notably those in the circum-Pacific, from Alaska through the North American Interior to the Andes and Indonesia, thence along the southern margins of the Neotethys through the Himalayas to western India, Madagascar and Ethiopea. The only comment that need be made here is that in the absence of Kepplerites in the southern palaeohemisphere, correlations with the primary GSSP have to be indirect. Here, as in other cases, the ‘G’ in GSSP should not be viewed as an indication of global correlation-potential. As a recognition of the fact that any time-plane defined by a Golden Spike is global (Callomon 2003b), its explicit mention in this context is redundant. PSSP, PrimarySSP, would be more to the point.

Action - It has been suggested that despite its legitimacy at the time (1990), de facto if not de jure legis ICS, the decision of the Callovian WG should perhaps be refreshed by another Callovian WG today. This presents a problem: who are its members? Because of the finality of the proceedings in 1990, there seems to have been no need for a subsequent formal meeting of the WG to deliberate on the problem of the GSSP, which we are told is the prime function of our WGs. An invitation some years ago to our readership to join the Callovian WG or to renew membership elicited one response. So the invitation is here repeated: if you wish to be a member of the Callovian WG, please let us know. More widely, if anyone has any comments or suggestions relating to the proposed submission to the ICS of an application for ratification of the previously agreed Callovian basal boundary GSSP, please send them in. But the basis for discussion has to be the proposal as outlined in Vancouver (Callomon & Dietl 2000).

Some references:

CALLOMON, J.H. 1985. Biostratigraphy, chronostratigraphy and all that – again! In: MICHELSEN, O. & ZEISS, A. (eds), International Symposium on Jurassic Stratigraphy, Erlangen,1984, 3, 612-624.

CALLOMON, J.H. 1991. Callovian Boundary Working-Group. Proposals for the designation of a Basal Boundary Stratotype (GSSP) and the definition of the Callovian Stage. Field Symposium held in Stuttgart and Albstadt-Ebingen, southern Germany, September 1990. Newsletter of the International Subcommission on Jurassic Stratigraphy, 20, 5–9. Lyon.

CALLOMON, J.H. 1993. The ammonite succession in the Middle Jurassic of East Greenland. Bulletin of the Geological Society of Denmark, 40, 83–113, 3 pls.

CALLOMON, J.H. 1995. Time from fossils: S.S. Buckman and Jurassic high-resolution geochronology. In: LE BAS, M.J. (ed), Milestones in Geology, Geological Society, London, Memoir 16, 127-150.

CALLOMON, J.H. 2003a. Essay Review: Stratigraphical Procedure, by P.F. RAWSON (ed) and 16 others, Professional Handbook series, Geological Society, London (2002). Proceedings of the Geologists’ Association, 114, 263–269.

CALLOMON, J.H. 2003b. The Middle Jurassic of western and northern Europe: its subdivisions, geochronology and correlations. In: INESON, J.R. & SURLYK, F. (eds), The Jurassic of Denmark and Greenland, Geological Survey of Denmark and Greenland Bulletin, 1, 61–74.

CALLOMON, J.H & DIETL, G. 2000. On the proposed Basal Boundary Stratotype (GSSP) of Middle Jurassic Callovian Stage. In: HALL, R.L. & SMITH, P.L. (eds), Advances in Jurassic Research 2000. GeoResearch Forum, 6, 41–54. Trans Tech Publications, Zürich.

CALLOMON, J.H., DIETL, G. & PAGE, K.N. 1989. On the ammonite faunal horizons and standard zonations of the Lower Callovian Stage in Europe. In ROCHA, R.B. & SOARES, A.F. (eds), 2^nd International Symposium on Jurassic Stratigraphy, Lisboa 1987, 1, 359-376. Universidade Nova de Lisboa, Lisbon.

SADLER, P.M. & STRAUSS, D.J. 1990. Estimation of completeness of stratigraphical sections using empirical data and theoretical models. Journal of the Geologicla Society of London, 147,471-485.

SCHINDEL, D.E. 1980. Micrographic sampling and limits of paleontologic resolution. Paleobiology, 6, 407-426.

SCHINDEL, D.E. 1982. Resolution analysis: a new approach to the gap in the fossil record. Paleobiology, 8, 340-353.

CALLOVIAN WORKING-GROUP

John CALLOMON, Convenor

ISJS Newsletter 35/2: 12-13 (2008)

It has been a quiet year in the Callovian. We have meanwhile seen the appearance of three huge collaborative proposals in support of the designation of basal boundary GSSPs, for the Bathonian, the Kimmeridgian and, ultimately, for the Hettangian and thereby for the Jurassic as a whole. These proposals have not emerged without intensive discussion over ends and means, both in previous pages of our Newsletter and in correspondence, at times quite vigorous, between members of the Working-Groups. I am afraid that on the one hand the much-delayed formal proposal for the Callovian basal boundary GSSP will not be on the same comprehensive scale, mainly because the resources in time and manpower simply have not been available.

Previous appeals for new members to join the Callovian W-G have met with little success. On the other hand, the reason could be that the main problem that GSSPs are supposed to solve, the typological definition of the timeplane marking the basal boundary of the Callovian Stage, was essentially solved 17 years ago. And no-one has complained or contested the choice since. The choice of locality for the primary standard GSSP, at Albstadt-Pfeffigen, was considered and then ratified nem. com. by a Working Group of 18 members at the time. The matter came up again for debate at the Krakow Symposium in 2006 and the question of possible alternative sections to be considered for the GSSP was raised. One proposal has since been put forward, based on the dramatic new discoveries in the Volga Basin on the Russian Platform that have been made in the course of the great Russian Jurassic renaissance we have seen during the last fifteen years or so. Those at the settlement of Prosek in the region of Nizhny Novgorod, on the Middle Volga, have now been described in a fine new paper by our colleagues Dmitry KISELEV and Michail ROGOV (2007, reference below). The ammonite biostratigraphy is based primarily on two genera, Cadoceras and Kepplerites, with widely intermittent incursions of some Macrocephalites but no perisphinctids. The closest resemblance is to the succession in East Greenland rather than that in central and north-western Europe, with similar problems of correlation. Quite properly, the first move has been a hierarchically upwards classification of the ammonite succession into a series of faunal horizons, of which eight have been distinguished. The lowest two are assigned to a single Infimum Zone in the Upper Bathonian, the following six to two Zones of the Lower Callovian, the Elatmae and Subpatruum Zones. But whereas the lowest two can be roughly correlated with the Calyx Zone of East Greenland, the higher, ‘Callovian’ ones, match at all closely neither those of East Greenland nor those of Europe. Their faunas seem to represent a Russian provinciality. And it remains uncertain where the base of the Callovian as defined in Swabia lies, at least at the precision of biohorizonal hronology. The diagnostic guide-species, Kepplerites keppleri, has not been unambiguously identified at Prozek, although its presence at Alatyr on the Sura, 200 km to the south-east, seems assured. Much depends here also on the specific identifications of the ammonites. To be used as guide-fossils at the level of time-resolution aimed at in the differentiation and correlations of faunal horizons, comparisons have to be of assemblages - biospecies - rather than of single or small numbers of individuals - morphospecies, possibly having extended ranges.

Unfortunately, the leading forms being used here, the Cadoceratinae, are in this sense not very good guide-fossils. It seems most appropriate, therefore, to treat the succession at Prozek for the time being as a candidate for a Russian secondary standard chronozonation. The ammonite biohorizonal successions now recognized around the Bathonian-Callovian transition in the classical areas of Swabia and England have recently also undergone a review, prompted by a summary of the results of detailed studies in recent years, by Volker DIETZE and colleagues, of Middle Jurassic exposures around the Ipf, a prominent hill on the western edge of the Ries impact crater at the Swabo-Bavarian border (reference below). The total number of biohorizons in the English Bathonian now stands at 20. Those in the Lower Callovian number 22, lying in a zonation of three standard Zones subdivided into eight Subzones. Even so, there are still discernible gaps waiting to be filled. The temporal resolving-power of ammonites in stratigraphical successions continues to be cause for amazement - at least, to me.

References:

DIETZE V., SCHWEIGERT G., CALLOMON J.H., DIETL G. & KAPITZKE, M. 2007. Der Mitteljura des Ipf-Gebietes (östliche Schwäbische Alb, Süddeutschland). Korrelation der süddeutschen Ammoniten- Faunenhorizonte vom Ober-Bajocium biszum Unter-Callovium mit Südengland und Frankreich. Zitteliana, A47, 105-125

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, 15, 485-515.

Callovian. Research by the Working Group, Convenor John CALLOMON, to select the best marker for the base of the basal zone and subzone of the Callovian Stage, and of the best section for GSSP were completed in the early 1990s. The marker and section selected are the Kepplerites keppleri horizon in the Albstadt-Pfeffingen, Swabia (S. Germany) section. A description and discussion were published in the Proceedings of 5th International Jurassic Symposium (GeoResearch Forum 6, 41-54, 2000). Unfortunately, the paperwork leading to a formal proposal was never completed at the time, but is now under way. At the Working Group meeting during the 7th International Jurassic Congress in Krakow some minority reservations were expressed and it was agreed that a possible alternative section on the Russian Platform should be examined. A proposal for discussion has been submitted to the Working Group.

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V. Callovian WG members