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Maximized biostratigraphic resolution across the 2‒Series 3 boundary interval calibrated with synchronous sea-level fluctuations and their impact on the biotic composition

Prof. Dr. Gerd Geyer

Project duration: 2012–2015

Supported by the German Research Foundation (DFG)

Summary

The research project dealt with a characterization of organisms and their assemblages as well as sedimentological criteria in various parts of the Cambrian continents across the Cambrian Series 2–Series 3 boundary interval. The research activities are primarily contributions to the global Cambrian subdivision project of the International Subcommission of Cambrian Stratigraphy. Particular emphasis was put on the taxonomy and biostratigraphy of which provide a base for intercontinental or subglobal correlation in the critical interval. The series of research activities conformed with current GSSP projects of the ISCS.

In total, more than 30 single projects were actively carried out, dealing with Cambrian rocks and fossils from Jordan, the Iran, Kyrgyzstan, northern Greenland, Morocco, Sweden, Denmark, northern Germany, eastern Canada, the Canadian cordillera, England, Poland, South China, Saxony and the Franconian Forest in Bavaria. Five publication presented global synopses without a specific regional focus.

Publications and proposals for the Subcommission on Cambrian Stratigraphy:

Bayet-Goll, A., Wilmsen, M., Geyer, G., Mahboubi, A. & Moussavi-Harami, R. 2014. Facies architecture, depositional environments and sequence stratigraphy of the Middle Cambrian Fasham and Deh-Sufiyan formations in the central Alborz, Iran. Facies 60: 815‒841, doi 10.1007/s10347-014-0401-9. Elicki, O. & Geyer, G. 2013. The Cambrian trilobites of Jordan – taxonomy, systematic and stratigraphic significance. Acta Geologica Polonica 63 (1): 1–56. Geyer, G. & Corbacho, J. 2015. The Burlingiidae (Trilobita): revised generic composition, stratigraphy, and the first species from the early Middle Cambrian of West Gondwana. GFF 137 (3): 212‒225, doi 10.1080/11035897.2015.1027266. Geyer, G. & Peel, J.S. 2017. Middle Cambrian trilobites from the Ekspedition Bræ Formation of North Greenland, with a reappraisal of the genus Elrathina. Journal of Paleontology 91 (2): 265–293. Geyer, G. & Vincent, T. 2014. The Paradoxides puzzle resolved – the appearance of the oldest paradoxidines and its bearing on the Cambrian Series 3 lower boundary. Paläontologische Zeitschrift 89 (3): 335‒398, doi 10.1007/s12542-014-0225-5. Geyer, G. 2014. Cambrian rocks in the Franconian Forest prove shallow marine deposition during a shift from West Gondwanan to sub-Baltican position. SDGG 85: 178. Geyer, G. 2015. Exotic trilobites from the lower–middle Cambrian boundary interval in Morocco and their bearing on the Cambrian Series 3 lower boundary. Paläontologische Zeitschrift 89 (4): 749–781, doi: 10.1007/s12542-014-0254-0 Geyer, G. 2016. Taxonomy of the ‘Micmacca’ group, new Cambrian Chengkouiidae (Trilobita) from Morocco, and their bearing on intercontinental correlation. Memoirs of the Association of Australasian Palaeontologists 49: 329–393. Geyer, G., Bayet-Goll, A., Wilmsen, M., Mahboubi, A. & Moussavi-Harami, R. 2014. Lithostratigraphic revision of the middle Cambrian (Series 3) and upper Cambrian () in northern and central Iran. Newsletters on Stratigraphy 47 (1): 21‒59. Geyer, G., Buschmann, B. & Elicki, O. 2013/2014. A new lowermost middle Cambrian (Series 3, 5) faunule from Saxony (Germany) and its bearing on the tectonostratigraphic history of the Saxothuringian domain. Paläontologische Zeitschrift 88: 239–262, doi 10.1007/s12542-013-0195-z. Geyer, G. & Landing, E. 2016. The and –Cambrian boundaries: a historical approach to a dilemma. In: Brasier, A. T., McIlroy, D. & McLoughlin, N. (eds.): Earth System Evolution and Early Life: a Celebration of the Work of Martin Brasier. Geological Society, London, Special Publications 448, http://doi.org/10.1144/SP448.10. Geyer, G., Peel, J.S., Streng, M., Voigt, S., Fischer, J. & Preuße, M. 2014. A remarkable Amgan (middle Cambrian, Stage 5) fauna from the Sauk Tanga, Madygen region, Kyrgyzstan. Bulletin of Geosciences (Prague) 89 (2): 375‒400. Landing, E. & Geyer, G. 2016. Comment on “ small shelly faunas of east Yunnan (South China) and their biostratigraphic implications” by B. Yang et al. [Palaeogeography, Palaeoclimatology, Palaeoecology 398 (2014) 28–58]. Palaeogeogr. Palaeoclimatol. Palaeoecol. (2016), http://dx.doi.org/10.1016/j.palaeo.2016.04.016 Landing, E., Geyer, G., Brasier, M.D. & Bowring, S.A. 2013. Base of global . Carbon isotope-biostratigraphic definition and correlation of the upper stage of the Terreneuvian Series. Proposal for the International Subcommission on Cambrian Stratigraphy, 51 pp. Landing, E., Geyer, G., Brasier, M.D. & Bowring, S.A. 2013. Cambrian Evolutionary Radiation: Context, correlation, and chronostratigraphy—Overcoming deficiencies of the first appearance datum (FAD) concept. Earth-Science Reviews 123: 133–172. Landing, E., Geyer, G., Brasier, M.D. & Bowring, S.A. 2013. Proposed base of global Cambrian Series 2 and Stage 3: A Carbon-isotope and biostratigraphic definition for the upper part of the traditional lower Cambrian. Proposal for the International Subcommission on Cambrian Stratigraphy, 55 pp. Landing, E., Geyer, G., Buchwaldt, R. & Bowring, S.A. 2014. Geochronology of the Middle Cambrian: a precise U‒Pb zircon date from the German margin of West Gondwana. Geological Magazine 152: 28–40, doi 10.1017/S0016756814000119 Landing, E., Geyer, G., Buchwaldt, R. & Bowring, S.A.. 2014. Geochronology of the Middle Cambrian: A precise U-Pb zircon date from the German margin of West Gondwana. Geological Magazine 152 (1): 28‒ 40, doi 10.1017/S0016756814000119. Peel, J.S., Streng, M., Geyer, G., Kouchinsky, A. & Skovsted, C.B. 2016. Ovatoryctocara granulata assemblage (Cambrian Series 2–Series 3 boundary) of Løndal, North Greenland. Memoirs of the Association of Australasian Palaeontologists 49: 241–282. Sundberg, F.A., Fletcher, T.P., Geyer, G., Kruse, P.D., McCollum, L.B., Pegel, T.V., Żylińska, A. & Zhuravlev, A.Yu. 2016. International correlation of the lower-middle Cambrian (Series 2-3, Stage 4-5). Memoirs of the Association of Australasian Palaeontologists 49: 83–124. Weidner, T., Geyer, G., Ebbestad, J. O. R. & von Seckendorff, V. 2015. Erratic boulders from Jutland, Denmark, feature an uppermost lower Cambrian fauna of the Lingulid Sandstone Member of Västergötland, Sweden. Bulletin of the Geological Society of Denmark 63: 59–86.