Reproduction of melting behavior for vitrified hillforts based on amphibolite, granite, and basalt lithologies
Autor: | José Marcial, John A. Wolff, Edward P. Vicenzi, Carolyn I. Pearce, Mia Englund, John S. McCloy, Mostafa Ahmadzadeh, Jack S. Clarke, Rolf Sjöblom, David L. Bollinger, Erik Ogenhall, Albert A. Kruger |
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Rok vydání: | 2020 |
Předmět: |
010506 paleontology
Glass production Materials science Solid Earth sciences Lithology Science Geochemistry Feldspar 01 natural sciences Article 0601 history and archaeology Vitrification 0105 earth and related environmental sciences Basalt Multidisciplinary 060102 archaeology business.industry Partial melting 06 humanities and the arts Mineralogy Amorphous solid Source rock visual_art visual_art.visual_art_medium Medicine business |
Zdroj: | Scientific Reports Scientific Reports, Vol 11, Iss 1, Pp 1-18 (2021) |
ISSN: | 2045-2322 |
Popis: | European Bronze and Iron Age vitrified hillforts have been known since the 1700s, but archaeological interpretations regarding their function and use are still debated. We carried out a series of experiments to constrain conditions that led to the vitrification of the inner wall rocks in the hillfort at Broborg, Sweden. Potential source rocks were collected locally and heat treated in the laboratory, varying maximum temperature, cooling rate, and starting particle size. Crystalline and amorphous phases were quantified using X-ray diffraction both in situ, during heating and cooling, and ex situ, after heating and quenching. Textures, phases, and glass compositions obtained were compared with those for rock samples from the vitrified part of the wall, as well as with equilibrium crystallization calculations. ‘Dark glass’ and its associated minerals formed from amphibolite or dolerite rocks melted at 1000–1200 °C under reducing atmosphere then slow cooled. ‘Clear glass’ formed from non-equilibrium partial melting of feldspar in granitoid rocks. This study aids archaeological forensic investigation of vitrified hillforts and interpretation of source rock material by mapping mineralogical changes and glass production under various heating conditions. |
Databáze: | OpenAIRE |
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