Assessment of the reason for the vitrification of a wall at a hillfort. The example of Broborg in Sweden

Sjöblom, Rolf; Hjärthner-Holdar, Eva; Pearce, Carolyn I.; Weaver, Jamie L.; Ogenhall, Erik; McCloy, John S.; Marcial, José; Vicenzi, Edward P.; Schweiger, Michael J.; Kruger, Albert A.

doi:10.1016/j.jasrep.2022.103459

Assessment of the reason for the vitrification of a wall at a hillfort. The example of Broborg in Sweden

Journal Article · Mon May 09 00:00:00 EDT 2022 · Journal of Archaeological Science: Reports

DOI:https://doi.org/10.1016/j.jasrep.2022.103459· OSTI ID:1869778

Sjöblom, Rolf ^[1]; Hjärthner-Holdar, Eva ^[2]; Pearce, Carolyn I. ^[3]; Weaver, Jamie L. ^[4]; ^[5]; ^[6]; ^[3]; Vicenzi, Edward P. ^[7]; Schweiger, Michael J. ^[3]; Kruger, Albert A. ^[8]

Luleå University of Technology (Sweden)
National Historical Museums, Uppsala (Sweden). Geoarchaeological Lab.; Luleå University of Technology (Sweden)
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)
National Historical Museums, Uppsala (Sweden). Geoarchaeological Lab.; Geoveta AB, Sollentuna (Sweden)
Washington State Univ., Pullman, WA (United States)
Smithsonian Institution, Suitland, MD (United States). Museum Conservation Institute
USDOE Office of River Protection (ORP), Richland, WA (United States)

It was discovered around 250 years ago that some of the rock material in the walls of some hillforts had been subjected to such high temperature that it had vitrified. This prompted a debate as to the reason for it that is still going on today: did the vitrification come about as a result of hostile action, by accident, or for the purpose of constructing the fort? The present paper is based on the prerequisite that hillforts are different, and therefore should be evaluated individually. All identifiable factors of interest should be included, and especially those that might disprove any alternative. Thus, incentives, competence and petrographic aspects were evaluated for the hillfort Broborg (dated Migration Period, in Sweden A.D. 400 - 550), and it is concluded that the vitrification came about for the purpose of constructing the fort. This capability was lost when mortar was introduced half a millennium later.

View Accepted Manuscript (DOE)

Research Organization:: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

Sponsoring Organization:: USDOE Office of Environmental Management (EM)

Grant/Contract Number:: AC05-76RL01830

OSTI ID:: 1869778

Report Number(s):: PNNL-SA-161025

Journal Information:: Journal of Archaeological Science: Reports, Journal Name: Journal of Archaeological Science: Reports Vol. 43; ISSN 2352-409X

Publisher:: ElsevierCopyright Statement

Country of Publication:: United States

Language:: English

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Assessment of the reason for the vitrification of a wall at a hillfort. The example of Broborg in Sweden

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