Underwater Cultural Heritage understands all traces of human existence having a cultural, historical, or archaeological character, which have been partially or totally underwater, in periodic or continuous forms for at least 100 years, according to UNESCO. This work is focused on two pieces extracted in 1999 from a shipwreck located in Bakio (Basque Country, Northern Spain). The two analyzed pieces were an iron anchor and a swivel gun, both exposed in Bakio's Town Hall after their restoration in 2005. The aim of this work is to study the elemental composition of archaeological metallic pieces extracted from underwater and the degradation processes that affect them. For that purpose, nondestructive analytical techniques were employed.Concretely, Raman spectroscopy and X-ray fluorescence spectroscopy were used to check the conservation state and to identify the raw materials that were used in the manufacture of those pieces. The analyses concluded that both artifacts were manufactured in cast iron, although the composition of the raw materials was not exactly the same. The main decaying compound was lepidocrocite (γ-FeO(OH)), a highly reactive iron phase that increases the corrosion rate of the artifacts, though other iron oxy-hydroxides were also detected in minor amounts. This compound together with the also found akaganeite (β-Fe 2 (OH) 3 Cl) were probably the responsible of the continuous oxidation of the metallic pieces, which are in a poor conservation state. Therefore, the applied treatment was not suitable for these pieces.
Cultural heritage often brings to mind elements like sculptures, paintings, monuments, and buildings as well as archeological objects. Today, underwater heritage and its surrounding environment are also considered part of cultural heritage because communities identify themselves with the natural landscape. This study is focused on a shipwreck belonging to the second half of the 15th century that was discovered in 1998 by chance in the sediments of the Urdaibai estuary, in Urbieta (Gernika, Basque Country), at 4 m underground. A scientific study presented in this work was performed, as this archeological site was absolutely out of context and in need of a preservation and conservation procedure. Therefore, our aim was to shed light on the origin of the shipwreck and to assess the conservation state to develop a precise conservation plan. Pursuing this objective, a first analysis on three selected groups of iron nails was performed, looking at the raw materials and degradation patterns through the knowledge of the alteration compounds. By means of nondestructive analytical techniques such as Raman spectroscopy and X‐ray fluorescence, the presence of iron, zinc, and silicon was detected in the outer layer of the iron samples. The analysis of the nails and wood of the shipwreck confirmed that the presence of zinc in the pieces indicates an important impact of the contaminated sediments deposited in the last 80 years on the upper part of the burial in which the shipwreck was located.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.