Tag Archives: sea shell

Bioerosion of shells on the beach – and in old Norwegian lime mortars

Posted on November 25, 2025 by Per Storemyr

Looking closely at shells on the beach, you will find that most have smaller and larger holes, tunnels and “galleries” made by boring organisms. This is bioerosion, a powerful part of the process that makes shells break down and eventually become part of a shell sand deposit. Along the coast of Norway, such deposits were sometimes dug for aggregate to make lime mortars for building medieval churches. And bioerosion of shell fragments in the mortars can still be seen under the microscope. It may aid the understanding of how the mortars were made. Continue reading →

Posted in Archaeology, lime burning, Marble, Weathering history | Tagged bioerosion, kalk, lime, lime mortar, lime mortar microscopy, Moster gamle kirke, Norway, Sakshaug gamle kirke, sea shell | 1 Comment

The Stones and Mortars of the Medieval Cathedral on the Faroe Islands

Posted on September 5, 2024 by Per Storemyr

Presented in Tórshavn earlier this year, “The Cathedral of Kirkjubøur” is a book covering all you ever wanted to know about building a big Gothic church in the middle of the North Atlantic – 700 years ago, and far away from contemporary European centres of stone architecture. Edited by Kirstin S. Eliasen and Morten Stige, the book contains 18 papers with various perspectives on the archaeology and building history. My contribution is written together with Faroese geologist Uni Árting: How were stone and lime procured on a remote archipelago that basically consist of basalt? Read on and download PDF of our paper. Continue reading →

Posted in New publications | Tagged ancient stone quarrying, basalt, building stone, Faroe islands, Kirkjubøur, lime mortar, medieval cathedral, old quarries, sea shell, soapstone | 6 Comments

Burning sea shells to make quicklime

Posted on November 10, 2018 by Per Storemyr

Burning sea shells to make quicklime once was a great tradition in the North-Atlantic region. In Millstone Park, Hyllestad (W-Norway), we have built two limekilns, reviving old lime burning traditions, involving craftspeople, volunteers and the public. Recently we burnt sea shells to make lime paint and mortar! Read about the experiment in a new poster and web article. Continue reading →