The Scottish Medieval Castles & Chapels Project is funded by Historic Environment Scotland. Led by Mark Thacker, now based at the University of Stirling, it aims to combine new methods of carbon-14 dating of mortar, biological information, and documentary evidence to reveal when these important buildings were constructed. Mark’s work has taken him far and wide in the West Highlands and Islands, even to North Rona, but the most successful application of the new approach has been at Fincharn Castle on Loch Aweside. Here carbon dating of the wood used to fire the lime, evidence of forest decline from pollen cores, and charter information, all point to a mid-13thC date of construction.
Mark Thacker dating Achinduin Castle
At his talk on 26 April 2016 , Mark told us that he has now turned his attention to Lismore, and his preliminary findings for the castles indicate building dates in the 13th century. Against previous suggestions, it looks as if Coeffin was built before Achinduin, and examination of the mortars has shown that the lime was burned from limestone (not shells) using varying amounts of oak, hazel, ash and birch as fuel. As well as further work on the castles, he will be moving on to the cathedral, and hopes to sample mortar from the wall footings of the ruined nave – which, we hope will be exposed during the proposed community archaeological dig this summer (keep an eye open for this!).
It looks as if it will be a lively summer on Lismore because Mark has offered to burn some lime on the island – an exercise in experimental archaeology. We also hope to be guided by him to find pre-kiln burning clamps on the island.
25 April 2016