Archaeometallurgical Analysis of Thirteenth-Century Bronze and Iron Construction Implements from the Walls of the Frankish Castle at Arsuf/Arsur

A discovery of the use of small metal plates was recently made at the Frankish sites of ‘Atlit, Arsur and Acre. These plates were used in the masonry, and we suggest for the first time their identification as construction implements that we term “spacers”. At Arsur, due to the homogenous use of relatively small ashlars to maintain level courses of finely built masonry walls, the spacers were found integrated into both interior and exterior walls. These spacers, dated to the second quarter of the thirteenth century, were subjected to metallurgical characterization. Some were made of copper-alloy, probably cast on site and having undergone surface finishing; while the others were corroded ferrous spacers, revealing a heterogeneous microstructure and too were probably produced on site. The present findings contribute to a better understanding of the construction method of stone masonry at Arsur Castle, enabling a deeper insight into a particular building technology.