Geochemical and petrological study of hammerscale : from an experimental approach to archaeological applications and implications
DOKPE
- Rodier, Jean ORCID University of Fribourg
- Serneels, Vincent (Degree supervisor) ORCID University of Fribourg
- 2025 ; Fribourg (Suisse) : Département de géosciences, sciences de la terre, Université de Fribourg
1 ressource en ligne (198 pages) ; 1 fichier pdf
PhD: Université de Fribourg (Suisse), 2025
English
In recent decades, hammerscale, the iron oxides particles produced during hot hammering, has largely been overlooked within the iron archaeometallurgical community, mainly due to its morphological variability, the complexity of obtaining consistent chemical analyses, and the requirement to analyze numerous samples to be representative. However, hammerscale occurs at nearly all blacksmithing sites across diverse historical periods worldwide, making it a precious artifact for study. This research investigates the potential of hammerscale to address unresolved questions surrounding iron production, circulation and consumption. A novel petrological and geochemical methodology was developed and first applied to experimental material, before being applied at three Iron Age archaeological sites: Weyersheim (LTA, 5th century BCE, France), Sévaz (LTA, 5th century BCE, Switzerland), and Vufflens (LTC-LTD, 2nd century BCE, Switzerland). This study includes 747 hammerscale samples from these sites, analyzed petrographically and chemically using LA-ICP-MS, supplemented by slag inclusion analysis on 12 iron artifacts. The findings reveal understanding previously inaccessible through other means. At the scale of the blacksmith, hammerscale analysis offers a new outlook on iron procurement strategies and technological practices. Additionally, the research provides novel vision into iron circulation patterns during the Early Iron Age. Results indicate that approximately 400 kg of a distinct iron type was processed at each of the Sévaz and Weyersheim sites, while bi-pyramid iron bars in circulation bear the same unique geochemical signature, suggesting a common geological source for most iron circulating in this region and period. These findings challenge the established paradigm of decentralized iron production during this era, pointing instead toward a more centralized production and distribution system, possibly under the control of ruling elites during the transition from the Hallstatt to La Tène A periods. To address local sourcing questions and contribute to the broader discourse on early Iron Age metal circulation, this research also analyzed 35 siderolithic iron ore samples from Swiss Jura Mountain using ICP-AES and ICP-MS, identifying the same atypical geochemical signature in the eastern section of the geological formation. The findings point out hammerscale value from an archaeological perspective, demonstrating that the methodologies developed in this study could be applied to forges across various contexts and time periods. Lastly, this research highlights the importance of integrating archaeology, statistics, geochemistry and petrology to address complex, multidisciplinary questions. It also emphasizes the necessity of critically reassessing established knowledge. This PhD aims to serve as an exploratory study, opening new pathways for future research in the field of iron archaeometallurgy.
- Faculty
- Faculté des sciences et de médecine
- Department
- Département de Géosciences
- Language
-
- English
- Classification
- Earth sciences
- License
- CC BY
- Open access status
- diamond
- Identifiers
- Persistent URL
- https://folia.unifr.ch/unifr/documents/332538
Statistics
Document views: 39
File downloads:
- phd_rodierj.pdf: 0