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During the 13th International Symposium on the Ordovician System in Novosibirsk, Russia, in July 2019, the next meeting was proposed, and agreed by the delegates, to take place in Estonia in 2023. It will be after 41 years and 10 meetings that the major event for all friends of the Ordovician System will return to Baltica. The last time was in August 1982 in Norway, organised by Prof. David Bruton and his colleagues from the Palaeontological Museum in Oslo. Over 150 scientists from 22 countries attended the meeting back then and we expect no less participants for the upcoming event in 2023.

Estonia is an appropriate place for an Ordovician meeting as the Ordovician rocks occur throughout the country and crop out within 1/3 of its territory. The conference venue, the capital city Tallinn, is largely located on Ordovician strata and its medieval old town is built from the Middle Ordovician limestone (which, by the way, is the national stone in Estonia) and belongs to the UNESCO World Heritage. The Ordovician rocks of Estonia have been attracting geology students since the early 18th Century and the rich and well-preserved fossil record has made the region renowned worldwide. Together with the neighbouring Baltoscandian countries, Estonia has continued to serve as one of the model areas for Ordovician studies.


The conference will take place in Tallinn on July 19-21, 2023. The venue will be in city centre, close to the medieval old town, various hotels, restaurants and the Baltic Sea.

Field trips

The conference will be preceded by excursion in Estonia introducing all classic Ordovician successions in the eastern Baltic region, and a post-conference field trip in Sweden (organised by Jan Ove Ebbestad, Uppsala University).

Ordovician-Silurian boundary outcrop in Reinu limestone quarry
This is the end. Ordovician-Silurian boundary beds in the Reinu quarry, central Estonia.

During the mid- and post-conference days, the participants will see all classical and some newly created outcrops of the Ordovician System, together with selected stops of late Cambrian and early Silurian strata across northern and central Estonia.

Cambrian-Ordovician boundary at Uuga cliff
Reaching out to the base of the System. Cambrian-Ordovician boundary beds at Cape Pakri, NW Estonia.


Early bird registration will be opened in late 2022. Expected deadline of extended abstracts and regular registration will be in April 2023.

Costs are expected to be similar to those of recent meetings, depending on the level of support from institutions and sponsors.


14th ISOS will be organised jointly by Tallinn University of Technology, University of Tartu, and the Geological Survey of Estonia. In case of questions, please do not hesitate to contact us: