Save the dates:


Early bird registration is now open. For pre-registration please follow this link. For paying and confirming your registration please follow this link. Expected deadline of extended abstracts and regular registration will be in April 2023.


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 and welcomes you in July 2023!

Schedule and deadlines

October 20, 2022

Registration open on conference website! Early-bird registration until December 31, 2022

March 2023

Distribution of the Second Circular

April 1, 2023

Deadline for short papers and abstracts

Deadline for paying the regular conference fee

June 2023

Distribution of the Third Circular

July 14, 2023

Arrival in Tallinn (for pre-conference excursion)

July 15-18, 2023

Pre-conference excursion: Ordovician of Estonia

July 18, 2023

Registration and Ice Breaker in Tallinn

July 19-21, 2023

Scientific sessions, conference Dinner

July 22, 2023

Travel from Tallinn to Stockholm for the Post-Conference Excursion

July 23-26, 2023

Post-conference excursion: Ordovician in Sweden

July 27, 2023

Departures from Stockholm


The scientific sessions are planned to take place in the Estonian Academy of Sciences, located in Toompea Hill in historical centre of Tallinn (address: Kohtu 6), within walking distance of various hotels, restaurants, and the Baltic Sea. Depending on the number of participants the venue may be subject to change.


The conference will be preceded by an 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). The pre-conference excursion is also an official excursion of the STRATI-2023 Conference. Please note that the number of places is limited on both excursions . The places are reserved in the order of registration and kept only if the fee is paid before April 1, 2023.

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

The pre-conference excursion will visit the Reinu limestone quarry near Rapla, which is a new outcrop of the Hirnantian Stage and the Ordovician-Silurian boundary in Estonia.

Pre-conference excursion: Ordovician of Estonia (July 15-18, 2023)

The 4-days excursion will focus on the Ordovician succession of northern and central Estonia. The cost is EUR 300 (includes bus travel, field lunches, excursion guidebook). The maximum number of participants is limited to 60. Please note that participants are responsible for arranging accommodation for the entire period of the excursion in Tallinn.

The stops to be visited include coastal cliffs exposing uppermost Cambrian to Upper Orovician siliciclastics and limestones, and active quarries and opencast mines for limestone and oil shale. Additionally, selected drill cores from central and southern Estonia piercing the entire Ordovician sequence will be shown at the Geological Survey's core study facility.

Post-conference excursion: Ordovician in Sweden (July 23-26, 2023)

The 4-days excursion will focus on the Ordovician successions of Västergötland (southwest of Sweden) and the Siljan district (central Sweden). The preliminary cost is EUR 600 (includes bus travel, four field lunches, three dinners, and accommodation for three days during the field excursion) and late price EUR 700. The maximum number of participants is limited to 45. The excursion will start from Uppsala, and please note that participants are responsible for arranging accommodation for the day before the excursion (22 to 23 July) and the day/days following the excursion (26 July onwards). A variety of hotels and other types of accommodation is available at with a price range from EUR 50 to EUR 200 per night.

The field trip to Västergötland (two days) will include Mt Kinnekulle with the condensed Middle Ordovician limestone succession, and the Hirnantian at Mt Billingen. Some highlights in the Siljan district (two days) include type sections for several of the Swedish Ordovician units and the famous Boda Limestone carbonate mounds.

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

About Estonia

Estonia is located in northern Europe between Finland, Russia, Latvia and Sweden. With an area of 45,000 km² and a population of ca 1.3 million, it is one of the smallest countries in Europe. The official language is Estonian, a Fenno-Ugric language spoken by 1.1 million people. Estonia is a member of the European Union, the Eurozone, NATO, the OECD, and the Schengen Visa Area.

Estonia is renowned for its economic and social freedom, sound education system, high level of digitisation and government e-services. The capital of Estonia is Tallinn, famous for its UNESCO World Heritage medieval old town. Tartu, the second largest city in the country, is best known for its university, established in 1632. Find out more at:,


Tallinn can be reached from many European cities by direct flights or via nearby larger airports, particularly Helsinki, Stockholm and Riga. From Scandinavia and Central Europe, Estonia is also reachable by car or bus. For details, please consult:

Please check if you need a visa for Schengen Area and contact the organisers in advance should you need an official invitation.


Conference participants are responsible for arranging accommodation for the entire period of stay, including the pre-conference excursion. A variety of hotels and other types of accommodation is available at, with the usual price range from EUR 50 to EUR 150 per night.


Limited support to young researchers from the IGCP 735 will be possible; please contact the conference secretary for further details. Note that only participants with presentations will be considered for support.

Registration and Icebreaker

Registration desk will be opened at the conference venue in the afteroon of July 18, 2023. Icebreaker will take place in the same location. Details in the Second Circular.

Conference dinner and spouse activities

The conference dinner will take place on July 20, 2023, in Tallinn city centre. The place will be announced in the Third Circular. Note that the Conference Dinner is not included in the registration fee.

Spouse activities will be organised for the period of scientific sessions if there is interest. Please indicate your interest in the registration form.

Short papers and abstracts

The conference volume will be published in the Estonian Journal of Earth Sciences, a SCOPUS-indexed Open Access journal. Participants are invited to submit short papers (3-4 printed pages) on any aspect of the Ordovician System worldwide. The manuscripts will be peer-reviewed and, upon recommendation, published as regular 'Short Communication' papers. Please prepare your manuscript using the ‘short paper template’ available on the conference website.

Alternatively, participants may submit abstracts (1 printed page), but note that these will not be indexed in SCOPUS and other citation databases as publications. No illustrations, references and acknowledgements are allowed in abstracts. Use the ‘abstract template’ file to prepare your abstract.


Regular oral presentations are limited to 15+5 minutes, and keynote talks to 25+5 minutes. Slides should be prepared in MS PowerPoint (.ppt, .pptx) or pdf formats and delivered to the organisers during on-site registration.

Posters will be displayed during the entire conference and presented during poster session.

Visit geological collections of Estonia

Large collections of Baltic Ordovician fossils and rocks are kept at the Department of Geology Tallinn University of Technology, the Estonian Museum of Natural History and at the Museum of Geology, University of Tartu (in Tartu). Participants of the conference are welcome to arrive earlier or leave later, in order to study these collections. Please contact the corresponding curators at your earliest convenience, but no later than May 1, 2023, to ensure the availability of the material. Data on many collection specimens, samples, localities etc have been digitised and made accessible online in the national geoscience data portal: Contact:

· Ursula Toom, Department of Geology, Tallinn University of Technology (

· Mare Isakar, Natural History Museum, Tartu University (

· Karin Truuver, Estonian Museum of Natural History ( )

Visit geological collections in Sweden

The main collections of Swedish Palaeozoic fossils and rocks are kept at the Museum of Evolution at Uppsala University, the Swedish Geological Survey (also in Uppsala) and the Swedish Museum of Natural History in Stockholm. Participants of the conference are welcome to study these collections. Please contact the corresponding curators at your earliest convenience, but no later than May 1, 2023, to ensure the availability of the material. Contact:

· Jan Ove R. Ebbestad, Museum of Evolution, Uppsala University ( )

· Linda Wickström, Geological Survey of Sweden (

· Jonas Hagström, Swedish Museum of Natural History, Stockholm (

Organising committee

Tõnu Meidla, chairman (University of Tartu)

Olle Hints, vice chair (Tallinn University of Technology)

Oive Tinn, secretary (University of Tartu)

Leho Ainsaar (University of Tartu)

Tavo Ani (Estonian Geological Survey)

Markus Maido (Estonian Geological Survey)

Siim Nirgi (Estonian Geological Survey)

Ursula Toom (Tallinn University of Technology)

Karin Truuver (Estonian Museum of Natural History)

Jan Ove R. Ebbestad (Museum of Evolution, Uppsala University, Sweden)

Contact and further information

E-mail and phone:

Oive Tinn (conference secretary): phone +372 737 6693,

Tõnu Meidla (chairman of organising committee): phone +372 514 4504

Olle Hints (pre-conference excursion): phone +372 51 30 157,

Jan Ove Ebbestad (post-conference excursion):