The archaeometry of tuyeres from the Great Zimbabwe and wider implications for its iron production technologies
(2017) In Studies in Global Archaeology 22. p.2-30- Abstract
- We report the first detailed chemical, microstructural and thermal analyses of a growing corpus of metallurgical tuyeres from the wider archaeological landscape of Great Zimbabwe in southern Africa. Of note is the fusion of the tuyeres in multiples, suggestive of widespread use of natural draft iron smelting technologies for large-scale production of iron most likely during the zenith period of Great Zimbabwe (ca 12th-16th century AD). Considerable variation in elemental composition between sites attributable to the adaptation of ceramic technology to local clay materials across the landscape is established through XRF analytical techniques. We also pick from petrographic studies, a bias towards self-tempered clays dominated by silt and... (More)
- We report the first detailed chemical, microstructural and thermal analyses of a growing corpus of metallurgical tuyeres from the wider archaeological landscape of Great Zimbabwe in southern Africa. Of note is the fusion of the tuyeres in multiples, suggestive of widespread use of natural draft iron smelting technologies for large-scale production of iron most likely during the zenith period of Great Zimbabwe (ca 12th-16th century AD). Considerable variation in elemental composition between sites attributable to the adaptation of ceramic technology to local clay materials across the landscape is established through XRF analytical techniques. We also pick from petrographic studies, a bias towards self-tempered clays dominated by silt and fine sand at some sites and the tendency for technicians to crush coarse sand and gravel a the others. Yet, and despite such variability in ceramic technology approaches, none of the studied sample had started to deform or melt at 1400oC, the maximum temperature of the furnace used for thermal analyses in the laboratory, revealing an unusually high refractoriness. We argue that such novel technologies natural draft furnaces would have built on an equally high degree of knowledge in ceramic technology, skilled prospection and manipulation of the material world. This brings out yet another intimate human-landscape interaction vividly depicted in Great Zimbabwe’s famous drystone architecture Great Zimbabwe (Less)
- Abstract (Swedish)
- Abstract
Recent research in the wider archaeological landscape of Great Zimbabwe recovered more
evidence of metallurgical tuyeres fused in varied multiples indicative of their use in natural
draft iron smelting technologies. We report the first detailed chemical, microstructural and
thermal analyses of these ceramic materials most likely associated with large-scale iron production at the zenith of the Great Zimbabwe civilization in southern Africa (ca 12th-16th century AD). The bulk chemistry of the studied sample reveals striking dissimilarities in elemental composition between sites. attributable to the adaptation of ceramic technology to local clay materials across the landscape. Only a few sits seem related,... (More) - Abstract
Recent research in the wider archaeological landscape of Great Zimbabwe recovered more
evidence of metallurgical tuyeres fused in varied multiples indicative of their use in natural
draft iron smelting technologies. We report the first detailed chemical, microstructural and
thermal analyses of these ceramic materials most likely associated with large-scale iron production at the zenith of the Great Zimbabwe civilization in southern Africa (ca 12th-16th century AD). The bulk chemistry of the studied sample reveals striking dissimilarities in elemental composition between sites. attributable to the adaptation of ceramic technology to local clay materials across the landscape. Only a few sits seem related, suggestive of preference for the same source or a type of clay with a similar soil chemistry, raising questions regarding contestations and negotiations over coveted materials by rival technicians. Highly refractive clays were of great priority to withstand the intense heat and long hours of smelt as proven by the resistance of the studied sample under maximum temperature exposure during analysis. Petrographic analyses reveal that self-tempered clays were most likely selected for this purpose as suggested by the dominance of silt and fine sand in samples. Wherever and whenever such clays were scarce crushed coarse sand and fine gravel were added to the clay to improve the stability and temperature resistance of the tuyeres, given the long hours of smelt and intense heat associated natural draft technologies. Based on these observations, we argue that the sophisticated iron technology of Great Zimbabwe built on by an advanced ceramic technology, revealing the existence of a high degree of engineering ingenuity in the area at some time, apart from its unique and famous drystone architecture. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/2b7c4d75-e6ad-4042-a8b8-daab4d0d7c95
- author
- Mtetwa, Ezekia and Lindahl, Anders LU
- organization
- publishing date
- 2017
- type
- Working paper/Preprint
- publication status
- published
- subject
- in
- Studies in Global Archaeology
- volume
- 22
- pages
- 28 pages
- publisher
- tudies in Global Archaeology
- ISSN
- 1651-1255
- ISBN
- 978-91-506-2591-2
- language
- English
- LU publication?
- yes
- additional info
- In E. Mtetwa. Technology, Ideology and Environment: The Social Dynamics of Iron Metallurgy in Great Zimbabwe, AD 900 to the Present (Paper III).
- id
- 2b7c4d75-e6ad-4042-a8b8-daab4d0d7c95
- alternative location
- https://uu.diva-portal.org/smash/get/diva2:1162620/FULLTEXT01.pdf
- date added to LUP
- 2023-12-06 16:16:13
- date last changed
- 2023-12-19 15:16:10
@misc{2b7c4d75-e6ad-4042-a8b8-daab4d0d7c95,
abstract = {{We report the first detailed chemical, microstructural and thermal analyses of a growing corpus of metallurgical tuyeres from the wider archaeological landscape of Great Zimbabwe in southern Africa. Of note is the fusion of the tuyeres in multiples, suggestive of widespread use of natural draft iron smelting technologies for large-scale production of iron most likely during the zenith period of Great Zimbabwe (ca 12th-16th century AD). Considerable variation in elemental composition between sites attributable to the adaptation of ceramic technology to local clay materials across the landscape is established through XRF analytical techniques. We also pick from petrographic studies, a bias towards self-tempered clays dominated by silt and fine sand at some sites and the tendency for technicians to crush coarse sand and gravel a the others. Yet, and despite such variability in ceramic technology approaches, none of the studied sample had started to deform or melt at 1400oC, the maximum temperature of the furnace used for thermal analyses in the laboratory, revealing an unusually high refractoriness. We argue that such novel technologies natural draft furnaces would have built on an equally high degree of knowledge in ceramic technology, skilled prospection and manipulation of the material world. This brings out yet another intimate human-landscape interaction vividly depicted in Great Zimbabwe’s famous drystone architecture Great Zimbabwe}},
author = {{Mtetwa, Ezekia and Lindahl, Anders}},
isbn = {{978-91-506-2591-2}},
issn = {{1651-1255}},
language = {{eng}},
note = {{Working Paper}},
pages = {{2--30}},
publisher = {{tudies in Global Archaeology}},
series = {{Studies in Global Archaeology}},
title = {{The archaeometry of tuyeres from the Great Zimbabwe and wider implications for its iron production technologies}},
url = {{https://uu.diva-portal.org/smash/get/diva2:1162620/FULLTEXT01.pdf}},
volume = {{22}},
year = {{2017}},
}