Radiocarbon dating is an archeological dating technique based on the radioactive decay of carbon-14 atoms (Renfrew and Bahn 2018, 108-140).  Ireland is a country where radiocarbon dating has been vital because of its climate, harsh weather patterns, and features.  Without this technique, key parts of Ireland’s history would continue to be murky or undetermined.

A recent find that involved the use of radiocarbon dating was that of a pagan deity statue (Figure 1), which gave insight into the religious and spiritual practices of the Irish people before St. Patrick made his way to the island (Gershon 2021).  Given that the excavation team found the statue in a bog, it was in excellent condition due to the natural preservation of the matrix.  

Figure 1. Archaeologist Cathy Morre standing next to the pagan deity statue found in a bog in Gortnacrannagh, Ireland. Photograph by Archaeological Management Solutions.

The process of radiocarbon dating involves finding an uncontaminated sample, running tests to determine the carbon-14 atoms’ decay level, and finally calibrating the found date to the modern time system (Renfrew and Bahn 2018, 108-140).  Once the samples from the statue went through this process, it was determined to be sculpted between 200 and 400 C.E. (Gershon 2021).  With this given time range, archaeologists could link together multiple ritualistic ruins and artifacts in the local area, allowing for a better understanding of the religious practices of the ancient Irish peoples.  Without radiocarbon dating, this would have been much more difficult to determine, and the time period of this site and others would be unclear.

Radiocarbon dating also helped immensely with dating ancient architecture in Ireland.  What has been learned from these sites has been essential for putting together a more accurate timeline of Irish civilization.  In 1992, Rainer Berger selected architecture, and then targeted the mortar within the infrastructures.  Specifically, he wanted to perform radiocarbon dating on the charcoal within the mortar to better understand when the buildings were constructed.  To isolate the carbon-14 atoms within the charcoal, the mortar was “treated with cold dilute hydrochloric acid until all inorganic carbonate [has] been destroyed” (Berger 1992, 882).  Once that step was complete, further cleansing commenced, eventually leaving just the desired atoms.  

The decay of the atoms obtained by Berger revealed that the small chapels, churches, and towers (Figure 2) he was analyzing were all constructed after the arrival of St. Patrick, meaning that they were made to withstand Viking attacks and raids during an era of violence and uncertainty.  This hints at cultural and societal values of the time, as well as the ‘why’ behind the unique architecture.  The accuracy of the radiocarbon dating also made it easier for archaeologists to individually order the buildings based on the time of construction, which was challenging to do in the past.

Figure 2. The Clonmacnoise Round Tower, one of the many sites throughout Ireland where   Carbon-14 isotopes were extracted from mortar. Photograph by Sarah Murphy.

All-in-all, this is just a glimpse into the vast array of archaeological progress that radiocarbon dating has catalyzed in Ireland.  As time goes on, radiocarbon dating will thicken Irish culture with layers of complexity and change how the history of Ireland is written.  

Further Readings:

Radical New History of Britain and Ireland Enabled by Precise Radiocarbon Dating

What Ancient Secrets Lie Beneath this Little-Known Irish Bog?

References:

Berger, Rainer. 1992. “14C Dating Mortar in Ireland.” Radiocarbon 34 (3): 880–89.

Gershon, Livia. 2021. “Eight-Foot-Tall, 1,600-Year-Old Statue of Pagan Deity Found in Ireland.” Smithsonian Magazine, 2021, sec. Cool Finds. https://www.smithsonianmag.com/smart-news/1600-year-old-wooden-idol-found-ireland-180978453/.

Renfrew, Colin, and Paul Bahn. 2018. Archaeology Essentials: Theories, Methods, and Practice. Fourth edition. Thames & Hudson. 108-140.