A recent study by archaeologists investigated round heavy metal objects from Seldal, located in the Haland region of western Sweden. Initially thought to be Bronze Age artifacts due to their shape and size, these objects were determined to be composed of copper-zinc-tin-reed alloys typical of the Iron Age and later periods.
Plano Convex Ingots from Seldal in Harland, Sweden. Image credit: Sabatini et al., doi: 10.1016/j.jasrep.2025.105312.
The ancient ingots were uncovered in the village of Seldal on Sweden’s west coast during the fall of 2022.
This artifact has been identified as a Plano-Convex Ingot.
“Plano-convex ingots, commonly known as ‘bread’ ingots or ‘casting cakes,’ were prevalent during the Bronze Age, though they vary in size, shape, and composition,” explains Serena Sabatini, a researcher at the University of Gothenburg.
“These artifacts are typically round with flat top surfaces and various inflated convex bottoms.”
“They are created by pouring molten metal into shallow molds or cavities in the ground.”
“Most of these ingots exhibit a rough, ‘bubbly’ top surface, indicating they were poured into an open casting mold, while the bottom remains smooth, as it was not exposed to air during production.”
“Due to their straightforward manufacturing process, they are widely found across Eurasia and were utilized both in prehistoric and historical periods.”
The Särdal Ingot measures 14-15.3 cm in diameter, approximately 2.5 cm thick, and weighs 1223.5 grams.
Notably, the ingot’s surface displays significant corrosion, especially on the rough, raised area.
The overall dimensions and weight of the ingot initially suggested it could be a Bronze Age find.
“At first, we believed the Seldal Ingot dated back to the Bronze Age,” the archaeologist noted.
“However, since it was found alone and not dated within an archaeological context, we opted for isotopic and chemical analysis to determine its composition and estimate a time frame.”
The analysis yielded surprising results, revealing that the ingot was made from copper-zinc-tin-reed alloys typical of the Iron Age and later.
“The findings emerged thanks to the collaborative spirit of the international scientific community exploring archaeological topics, allowing us to identify the isotopic and elemental characteristics of the Seldal ingots, which closely resemble artifacts from two sites found in the Iwawa Lakeland region of northeastern Poland.
Research into the Baltic Sea area, which had a robust network connected to western Sweden and southern Scandinavia during the Roman Iron Age, indicates that the alloys from both Seldal and Iwawa Lakeland were present in the region during the latter half of the 1st millennium BCE.
“Thus, we propose that the Plano Convex Ingots from Harland and the ingots from Poland represent the outcomes of a metallic maritime trade linking Scandinavia, the Baltic Sea, and the Iberian Peninsula.”
Their paper will appear in the October 2025 edition of Journal of Archaeological Science: Report.
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Serena Sabatini et al. 2025. Iron Age Metals Trade between the Atlantic and the Baltic Sea: New insights from the first complete Plano-Convex Ingot found in Sweden and Ingot Rod in Iwawa Lakeland, northeastern Poland. Journal of Archaeological Science: Report 66:105312; doi:10.1016/j.jasrep.2025.105312
Source: www.sci.news
