eesti teaduste
akadeemia kirjastus
SINCE 1952
Earth Science cover
Estonian Journal of Earth Sciences
ISSN 1736-7557 (Electronic)
ISSN 1736-4728 (Print)
Impact Factor (2020): 0.789

Upper Wenlock δ13C chemostratigraphy, conodont biostratigraphy and palaeoecological dynamics in the Ledai-179 drill core (Eastern Lithuania); pp. 293–299

Full article in PDF format | doi: 10.3176/earth.2014.33

Sigitas Radzevičius, Andrej Spiridonov, Antanas Brazauskas, Audrius Norkus, Tõnu Meidla, Leho Ainsaar


Based on the integrated chemostratigraphic and lithostratigraphic studies, as well as biostratigraphic and palaeo­ecological analyses of conodonts in the Ledai-179 core, we present a combined model of change in the upper Wenlock and lowermost Ludlow strata of the inner shelf settings in the eastern part of the Baltic Basin. The comparison of the δ13C trend, and conodont and lithological successions confirms previous suggestions that the Birštonas and Nevėžis formations correspond to the Homerian. This is quite unexpected, however, that the chronostratigraphic position of the Širvinta Formation changed from the Gorstian to the upper part of the Homerian. The numerical biostratigraphic changepoint analyses of local conodont richness, per capita immigration and also per capita extirpation rates revealed several episodes of permanent change. These episodes of dynamic states either preceded or postdated the Mulde extinction interval at the beginning of the late Homerian δ13C excursion, which points to possible transient effects of this extinction event on conodonts.


Auger, I. E. & Lawrence, C. E. 1989. Algorithms for the optimal identifcation of segment neighborhoods. Bulletin of Mathematical Biology, 51, 39–54.

Brazauskas, A. 1993. Konodonty i biostratigrafiya silura Litvy [Conodonts and Silurian Biostratigraphy of Lithuania]. PhD thesis, Vilnius University, Vilnius, 336 pp. [in Russian].

Calner, M. & Jeppsson, L. 2003. Carbonate platform evolution and conodont stratigraphy during the middle Silurian Mulde Event, Gotland, Sweden. Geological Magazine, 140, 173–203.

Cramer, B. D., Condon, D. J., Söderlund, U., Marshall, C., Worton, G. J., Thomas, A. T., Calner, M., Ray, D. C., Perrier, V., Boomer, I., Patchett, P. J. & Jeppsson, L. 2012. U–Pb (zircon) age constraints on the timing and duration of Wenlock (Silurian) paleocommunity collapse and recovery during the ‘Big Crisis’. Bulletin of the Geological Society of America, 124, 1841–1857.

Jaeger, H. 1991. Neue Standard-Graptolithenzonenfolge nach der ‘Großen Krise’ an der Wenlock/Ludlow-Grenze (Silur). Neues Jahrbuch für Geologie und Paläontologie Abhandlungen, 182, 303–354.

Jeppsson, L., Aldridge, R. J. & Dorning, K. J. 1995. Wenlock (Silurian) oceanic episodes and events. Journal of the Geological Society (London), 152, 487–498.

Kiipli, T., Einasto, R., Kallaste, T., Nestor, V., Perens, H. & Siir, S. 2011. Geochemistry and correlation of volcanic ash beds from the Rootsiküla Stage (Wenlock–Ludlow) in the eastern Baltic. Estonian Journal of Earth Sciences, 60, 207–219.

Killick, R. & Eckley, I. A. 2013. Changepoint: an R Package for Changepoint Analysis. R package version 3.1.0, URL. [accessed 14 October 2014].

Koren¢, N. T. 1987. Graptolite dynamics in Silurian and Devonian time. Bulletin of the Geological Society of Denmark, 35, 149–159.

Paškevičius, J., Lapinskas, P., Brazauskas, A., Musteikis, P. & Jacyna, J. 1994. Stratigraphic revision of the regional stages of the Upper Silurian part in the Baltic Basin. Geologija (Vilnius), 17, 64–87.

Patzkowsky, M. E. & Holland, S. M. 2012. Stratigraphic Paleobiology: Understanding the Distribution of Fossil Taxa in Time and Space. University of Chicago Press, Chicago, 256 pp.

Purnell, M. A., Donoghue, P. C. & Aldridge, R. J. 2000. Orientation and anatomical notation in conodonts. Journal of Paleontology, 74, 113–122.<0113:OAANIC>2.0.CO;2

Porębska, E., Kozłowska-Dawidziuk, A. & Masiak, M. 2004. The lundgreni event in the Silurian of the East European Platform, Poland. Palaeogeography, Palaeoclimatology, Palaeoecology, 213, 271–294.

R Core Team. 2014. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria. R package version 3.1.0, URL [accessed 14 October 2014].

Radzevičius, S., Spiridonov, A. & Brazauskas, A. 2014. Integrated middle–upper Homerian (Silurian) strati­graphy of the Viduklė-61 well, Lithuania. GFF, 136, 218–222.

Viira, V. & Einasto, R. 2003. Wenlock–Ludlow boundary beds and conodonts of Saaremaa Island, Estonia. Proceedings of the Estonian Academy of Sciences, Geology, 52, 213–238.

Back to Issue