New light on plant ash glass found in Africa: evidence for Indian Ocean Silk Road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century AD from Malindi and Mambrui, Kenya

Seventeen glass vessels and twenty glass beads recovered from the excavations at the ancient city of Malindi and the archaeological site of Mambrui in Kenya, east Africa were analysed using electron probe microanalysis (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS...

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Main Authors: Siu, Ieong, Henderson, Julian, Qin, Dashu, Ding, Yu, Cui, Jiangfeng, Ma, Hongjiao
Format: Article
Language:English
Published: Public Library of Science 2020
Online Access:https://eprints.nottingham.ac.uk/64812/
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author Siu, Ieong
Henderson, Julian
Qin, Dashu
Ding, Yu
Cui, Jiangfeng
Ma, Hongjiao
author_facet Siu, Ieong
Henderson, Julian
Qin, Dashu
Ding, Yu
Cui, Jiangfeng
Ma, Hongjiao
author_sort Siu, Ieong
building Nottingham Research Data Repository
collection Online Access
description Seventeen glass vessels and twenty glass beads recovered from the excavations at the ancient city of Malindi and the archaeological site of Mambrui in Kenya, east Africa were analysed using electron probe microanalysis (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The results show that all of the glass samples are soda-lime-silica glass. They belong to the high alumina -plant ash glass type, characterised by high alumina and relatively low calcium contents, widely distributed in eastern (10th – 16th centuries AD) and southern Africa (13th - 15th centuries AD), Central Asia (9th – 14th centuries AD) and southeast Asia (12th – 13th centuries AD), made with plant ashes and sands. This is an understudied glass type for which previous research has indicated there were three types. When compared with published research on such glasses using Zr, Ti, Ba, Cr, La, Li, Cs, Na2O, MgO and CaO we have identified at least four different compositional groups of v-Na-Al glass: Types A, B, C and D. By comparing the results with contemporary v-Na-Al glass vessels and beads from Central Asia, Africa, and southeast Asia we show that most of the Malindi and Mambrui glass share similar characteristics to the compositions of Mapungubwe Oblate and some of the Madagascar glass beads from southern Africa. They belong to Type A v-Na-Al glass which is characterised by an elevated level of Ti and Ba and a relatively high ratios of Cr/La, relatively low Zr concentrations and low ratios of Zr/Ti. Differences in Zr, Li, MgO and Na2O concentrations in Type A glass indicates that there are subgroups which might derive from different glass workshop(s) specialising in Type A v-Na-Al glass production. Comparison with the chemical compositions of glass from Ghazni, Afghanistan and Termez, Uzbekistan, and by using lead isotope analysis, we suggest v-Na-Al glass was manufactured in Central Asia and possibly worked into vessels and beads there.
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spelling nottingham-648122021-03-24T03:02:06Z https://eprints.nottingham.ac.uk/64812/ New light on plant ash glass found in Africa: evidence for Indian Ocean Silk Road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century AD from Malindi and Mambrui, Kenya Siu, Ieong Henderson, Julian Qin, Dashu Ding, Yu Cui, Jiangfeng Ma, Hongjiao Seventeen glass vessels and twenty glass beads recovered from the excavations at the ancient city of Malindi and the archaeological site of Mambrui in Kenya, east Africa were analysed using electron probe microanalysis (EPMA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The results show that all of the glass samples are soda-lime-silica glass. They belong to the high alumina -plant ash glass type, characterised by high alumina and relatively low calcium contents, widely distributed in eastern (10th – 16th centuries AD) and southern Africa (13th - 15th centuries AD), Central Asia (9th – 14th centuries AD) and southeast Asia (12th – 13th centuries AD), made with plant ashes and sands. This is an understudied glass type for which previous research has indicated there were three types. When compared with published research on such glasses using Zr, Ti, Ba, Cr, La, Li, Cs, Na2O, MgO and CaO we have identified at least four different compositional groups of v-Na-Al glass: Types A, B, C and D. By comparing the results with contemporary v-Na-Al glass vessels and beads from Central Asia, Africa, and southeast Asia we show that most of the Malindi and Mambrui glass share similar characteristics to the compositions of Mapungubwe Oblate and some of the Madagascar glass beads from southern Africa. They belong to Type A v-Na-Al glass which is characterised by an elevated level of Ti and Ba and a relatively high ratios of Cr/La, relatively low Zr concentrations and low ratios of Zr/Ti. Differences in Zr, Li, MgO and Na2O concentrations in Type A glass indicates that there are subgroups which might derive from different glass workshop(s) specialising in Type A v-Na-Al glass production. Comparison with the chemical compositions of glass from Ghazni, Afghanistan and Termez, Uzbekistan, and by using lead isotope analysis, we suggest v-Na-Al glass was manufactured in Central Asia and possibly worked into vessels and beads there. Public Library of Science 2020-08-13 Article PeerReviewed application/pdf en cc_by https://eprints.nottingham.ac.uk/64812/1/New%20light%20on%20plant%20ash%20glass%20found%20in%20Africa.pdf Siu, Ieong, Henderson, Julian, Qin, Dashu, Ding, Yu, Cui, Jiangfeng and Ma, Hongjiao (2020) New light on plant ash glass found in Africa: evidence for Indian Ocean Silk Road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century AD from Malindi and Mambrui, Kenya. PLoS ONE . pp. 1-26. ISSN 1932-6203 https://doi.org/10.1371/journal.pone.0237612 doi: 10.1371/journal.pone.0237612 doi: 10.1371/journal.pone.0237612
spellingShingle Siu, Ieong
Henderson, Julian
Qin, Dashu
Ding, Yu
Cui, Jiangfeng
Ma, Hongjiao
New light on plant ash glass found in Africa: evidence for Indian Ocean Silk Road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century AD from Malindi and Mambrui, Kenya
title New light on plant ash glass found in Africa: evidence for Indian Ocean Silk Road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century AD from Malindi and Mambrui, Kenya
title_full New light on plant ash glass found in Africa: evidence for Indian Ocean Silk Road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century AD from Malindi and Mambrui, Kenya
title_fullStr New light on plant ash glass found in Africa: evidence for Indian Ocean Silk Road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century AD from Malindi and Mambrui, Kenya
title_full_unstemmed New light on plant ash glass found in Africa: evidence for Indian Ocean Silk Road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century AD from Malindi and Mambrui, Kenya
title_short New light on plant ash glass found in Africa: evidence for Indian Ocean Silk Road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century AD from Malindi and Mambrui, Kenya
title_sort new light on plant ash glass found in africa: evidence for indian ocean silk road trade using major, minor, trace element and lead isotope analysis of glass from the 15th—16th century ad from malindi and mambrui, kenya
url https://eprints.nottingham.ac.uk/64812/
https://eprints.nottingham.ac.uk/64812/
https://eprints.nottingham.ac.uk/64812/