In addition to several informal meetings within the team in the Åland Islands, mortar dating has also been presented at different international conferences:

The Fourth International Mortar Dating Workshop – Age of Anthroponogenic Carbonates: Radiocarbon Dating of Mortars, Limes and Stucco. at the ETH Hönggerberg. Science City Zürich. 9-11-9.2015, organizer Irka Hajdas.

The main reason with this workshop was to discuss the inter-comparison between different methods of dating mortar, especially focusing on different preparation methods. Anonymous samples of mortar were sent around to the 14C-AMS laboratories, to find out which method was best suited for what kind of mortar. Future collaboration was also discussed, and also which international conferences to participate in during 2016. It was decided that we should all go as a group and aim at publishing our results jointly. Thus the inter-comparison should be published in the 14C&Archaeology 2016 (Edingburgh) proceedings.


Mark Van Strydonck, Sophie Hueglin, Alf Lindroos, Danuta Michalska, Jan Heinemeier, Roald Hayen, Marta Carosselli, Michale Toffolo, Andrea Matschi, Petra Ohnsorg, Reta Marti, Peter Barta, Ester Ferreira, Asel Maria Guilars and Irka Hajdas.


ETH Zürich, Tutto Gruppo 2015


Zürich, Tutto Gruppo 2 Lindenhof

Irka doing sequential dissolution

Irka Haidas doing the sequential solution at the AMS-laboratory at ETH Hönggerberg – Science City Zürich.

The Third International Mortar Dating Workshop

The Workshop was arranged in Padova, Italy, April 14-16 2014:

3 md workshop Padova program

For more information about the program, and for abstracts, see:

The 7th International Symposium in Radiocarbon and Archaeology

In April 2013 one entire session was devoted to mortar dating at the 7th International Symposium in Radiocarbon and Archaeology. At an informal gathering during the symposium the future of the network was further discussed.

Ghent 2013 mortar group.

Participating at the mortar dating discussions in Ghent: Upper row; Gianluca Pesce (second from the left), Peter Barta, Alf Lindroos, Christine Oberlin, Irka Haidas, Elisabetta Boaretto, Roald Hayen, Magdalena Salas. Lower row: Jan Heinemeier, Sara Nonni, Åsa Ringbom, Isabella Passariello, Damia Ramis.


The second International Mortar Dating Workshop

The workshop took place in Mallorca, September 2012. Organizer was Mark Van Strydonck. This time a wider circle of researchers had gathered, notably also from Belgium, Italy, and Switzerland. The lime burials of the Balearic Islands were in focus both in presentations, and in interesting excursions guided by specialists in the field. A firmer network of international and interdisciplinary researchers was formed. It was also decided that mortar dating should be presented in a separate session at an international conference.

Mallorca workshop 2012

Participating on the second International Mortar Dating Workshop in Mallorca were (from the left): Gregory Hodgins, Tucson, Arizona, US, Roald Hayen, Brussels, Belgium, Mark Van Strydonck, Brussels, Belgium, Vincent Debonne, Ghent, Belgium, Irka Haidas, Zürich, Switzerland, Guy de Mulder (hidden behind Irka), Ghent, Belgium, Alf Lindroos, Åbo, Finland, Tess Van den Brande, Brussels, Belgium, Jesse Palmer Jan Heinemeier, Aarhus, Denmark, Åsa Ringbom, Åbo, Finland, Robert Hohlfelder, Boulder, Colorado, US, Kathryn Barth, Boulder, Colorado, Fabio Marzaioli, Naples, Italy,  Damia Ramis,  Magdalena Salas and Dolors Domeniquez Henares, Mallorca.

The Second International Mortar Dating Workshop Mallorca 2012 program

The first International Mortar Dating Workshop

The workshop took place in Turku (Åbo) and Åland in August 2010. Organizers were members of the Finnish team.

The retirement of Åsa Ringbom, project leader since 1994, activated the idea to gather researchers, both internationally and nationally, who had shown an interest in mortar dating. Here first steps of an international network were taken, with many informal and fruitful discussions about the future of mortar dating.


Those who participated in the workshop were (from the left):

Jan Heinemeier, Aarhus Denmark, John Hale, Louisville, Kentucky, US, Mark Van Strydonck, Brussels, Belgium, Kari Uotila, Turku, Finland, Tanja Ratilainen, Turku, Finland, Gregory Hodgins, Tucson, Arizona, US,  Herlinde Borms, Brussels, Belgium, Alf Lindroos, Åbo Finland, Åsa Ringbom, Åbo, Finland, Markku Oinonen, Helsinki, Finland, Pia Sjöberg, Åbo, Finland, Joakim Hansson, Visby, Sweden, Kathryn Barth, Colorado, US, Robert Hohlfelder, Colorado, US, Pia Sonck-Koota, Åbo, Finland.

The First International Mortardating workshop 2010, program

The 7th International Symposium in Radiocarbon and Archaeology, Ghent

The 6th International Symposium in Radiocarbon and Archaeology, Cyprus

the 20th International Radiocarbon conference, Hawaii;

Building Roma Eaterna. Current research on Roman Mortar and Concrete, Rome;

the Archaeological Institute of America, Annual Meeting in Chicago;

The Second International Conference in Construction History, Cambridge, UK; 2006, 19th international Radiocarbon Conference, Oxford;

The XV International Congress of Classical Archaeology, Harvard;

the Archaeological Institute of America,  Annual Meeting in Chicago;

Medieval Europe in Bruges 1997;