Restoration of the Notre Dame, after the fire in 2019 that heavily damaged the cathedral, found that the Paris site is the "first known Gothic cathedral where iron was massively used as a proper construction material to bind stones throughout its entire construction," stated a recent study conducted by the Paris 8 University Vincennes-Saint-Denis.
The peer-reviewed study, published in the journal Plos One, states that six of the iron staples used the construct the cathedral were able to be dated back due to the "development of an innovative methodology based on radiocarbon dating" in the 12th and 13th centuries.
The 2019 fire incident at the cathedral allowed researcher Maxime L'Héritier and other colleagues to access areas and parts of the archeological site that were once concealed to find numerous iron staples used in the construction.
Chemical analyses by the researchers into the material reveal it came from a medieval Parisian building yard, and suggest that the iron staples were used in the earliest stages of Notre Dame's building process in the 1160s.
Why is the research important?
The research is important because it may also provide more insight into the iron trade and circulation of 12th and 13th century Paris. However, the authors of the study noted that more analyses of the iron samples at the site are needed in order to expand their research in the French capital's iron market.
What they do know, is that many of the iron staples can be forged by welding together pieces of iron that were found from a diverse array of supply sources.