Animal, vegetable or mineral?

Characterising shell-lime, maerl-lime and limestone-lime mortar evidence from the Late Norse and Medieval site of Tuquoy, Orkney

Mark Thacker, John Hughes, Nic Odling

Research output: Contribution to conferenceAbstract

Abstract

Recent examination of an extensive curated assemblage of mortar samples, removed from the Late Norse and Medieval site of Tuquoy (Orkney) during excavation in the 1980s, suggested the collection was associated with distinct groups of compositionally contrasting materials related to discrete constructional events. Subsequent petrographic analysis supported this early interpretation and presented evidence for a remarkable series of phase-specific mortars, bound with a range of different biogenic and geogenic lime source materials - including marine shell, coralline algae (maerl) and limestone. Wider landscape survey highlighted the broad range of exposed calcareous materials in the coastal and sedimentary environments dominating the Northern Isles of Scotland today, and that many of these different potential lime sources were exploited by craftspeople at different times in the Medieval and later period is now clear.

Given the high significance of the Tuquoy mortar study for our understanding of the development of this culturally important site, and as a prelude to more general publication of the wider archaeological project, a further investigation of selected samples from the mortar assemblage is now being undertaken through a range of geoscientific techniques. This paper presents emerging evidence from a comparative petrographic, SEM-EDS and XRD study designed to further characterise these various mortar materials, and challenge those previous interpretations of contrasting building lime sources. Like most environmental archaeological investigations, this study is essentially concerned with interpreting the depositional histories of surviving materials, but with a particular focus on establishing the distinction between (anthropogenic) kiln relict and (natural) added temper mixtures when both contain biogenic and geogenic clasts.
Original languageEnglish
Pages107-107
Number of pages1
Publication statusPublished - 19 Jun 2019
Event5th Historic Mortars Conference 2019 - Universidad de Navarra, Pamplona, Spain
Duration: 19 Jun 201921 Jun 2019
Conference number: 5
https://www.unav.edu/en/web/historic-mortars-conference

Conference

Conference5th Historic Mortars Conference 2019
Abbreviated titleHMC 2019
CountrySpain
CityPamplona
Period19/06/1921/06/19
Internet address

Fingerprint

mortar
Medieval
vegetable
lime
limestone
shell
animal
mineral
coralline alga
clast
excavation
scanning electron microscopy
X-ray diffraction
material
history

Keywords

  • Shell-Lime
  • Maerl-Lime
  • Petrography
  • Archaeology
  • Medieval

Cite this

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title = "Animal, vegetable or mineral?: Characterising shell-lime, maerl-lime and limestone-lime mortar evidence from the Late Norse and Medieval site of Tuquoy, Orkney",
abstract = "Recent examination of an extensive curated assemblage of mortar samples, removed from the Late Norse and Medieval site of Tuquoy (Orkney) during excavation in the 1980s, suggested the collection was associated with distinct groups of compositionally contrasting materials related to discrete constructional events. Subsequent petrographic analysis supported this early interpretation and presented evidence for a remarkable series of phase-specific mortars, bound with a range of different biogenic and geogenic lime source materials - including marine shell, coralline algae (maerl) and limestone. Wider landscape survey highlighted the broad range of exposed calcareous materials in the coastal and sedimentary environments dominating the Northern Isles of Scotland today, and that many of these different potential lime sources were exploited by craftspeople at different times in the Medieval and later period is now clear. Given the high significance of the Tuquoy mortar study for our understanding of the development of this culturally important site, and as a prelude to more general publication of the wider archaeological project, a further investigation of selected samples from the mortar assemblage is now being undertaken through a range of geoscientific techniques. This paper presents emerging evidence from a comparative petrographic, SEM-EDS and XRD study designed to further characterise these various mortar materials, and challenge those previous interpretations of contrasting building lime sources. Like most environmental archaeological investigations, this study is essentially concerned with interpreting the depositional histories of surviving materials, but with a particular focus on establishing the distinction between (anthropogenic) kiln relict and (natural) added temper mixtures when both contain biogenic and geogenic clasts.",
keywords = "Shell-Lime, Maerl-Lime, Petrography, Archaeology, Medieval",
author = "Mark Thacker and John Hughes and Nic Odling",
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day = "19",
language = "English",
pages = "107--107",
note = "5th Historic Mortars Conference 2019, HMC 2019 ; Conference date: 19-06-2019 Through 21-06-2019",
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}

Thacker, M, Hughes, J & Odling, N 2019, 'Animal, vegetable or mineral? Characterising shell-lime, maerl-lime and limestone-lime mortar evidence from the Late Norse and Medieval site of Tuquoy, Orkney' 5th Historic Mortars Conference 2019, Pamplona, Spain, 19/06/19 - 21/06/19, pp. 107-107.

Animal, vegetable or mineral? Characterising shell-lime, maerl-lime and limestone-lime mortar evidence from the Late Norse and Medieval site of Tuquoy, Orkney. / Thacker, Mark; Hughes, John; Odling, Nic.

2019. 107-107 Abstract from 5th Historic Mortars Conference 2019, Pamplona, Spain.

Research output: Contribution to conferenceAbstract

TY - CONF

T1 - Animal, vegetable or mineral?

T2 - Characterising shell-lime, maerl-lime and limestone-lime mortar evidence from the Late Norse and Medieval site of Tuquoy, Orkney

AU - Thacker, Mark

AU - Hughes, John

AU - Odling, Nic

PY - 2019/6/19

Y1 - 2019/6/19

N2 - Recent examination of an extensive curated assemblage of mortar samples, removed from the Late Norse and Medieval site of Tuquoy (Orkney) during excavation in the 1980s, suggested the collection was associated with distinct groups of compositionally contrasting materials related to discrete constructional events. Subsequent petrographic analysis supported this early interpretation and presented evidence for a remarkable series of phase-specific mortars, bound with a range of different biogenic and geogenic lime source materials - including marine shell, coralline algae (maerl) and limestone. Wider landscape survey highlighted the broad range of exposed calcareous materials in the coastal and sedimentary environments dominating the Northern Isles of Scotland today, and that many of these different potential lime sources were exploited by craftspeople at different times in the Medieval and later period is now clear. Given the high significance of the Tuquoy mortar study for our understanding of the development of this culturally important site, and as a prelude to more general publication of the wider archaeological project, a further investigation of selected samples from the mortar assemblage is now being undertaken through a range of geoscientific techniques. This paper presents emerging evidence from a comparative petrographic, SEM-EDS and XRD study designed to further characterise these various mortar materials, and challenge those previous interpretations of contrasting building lime sources. Like most environmental archaeological investigations, this study is essentially concerned with interpreting the depositional histories of surviving materials, but with a particular focus on establishing the distinction between (anthropogenic) kiln relict and (natural) added temper mixtures when both contain biogenic and geogenic clasts.

AB - Recent examination of an extensive curated assemblage of mortar samples, removed from the Late Norse and Medieval site of Tuquoy (Orkney) during excavation in the 1980s, suggested the collection was associated with distinct groups of compositionally contrasting materials related to discrete constructional events. Subsequent petrographic analysis supported this early interpretation and presented evidence for a remarkable series of phase-specific mortars, bound with a range of different biogenic and geogenic lime source materials - including marine shell, coralline algae (maerl) and limestone. Wider landscape survey highlighted the broad range of exposed calcareous materials in the coastal and sedimentary environments dominating the Northern Isles of Scotland today, and that many of these different potential lime sources were exploited by craftspeople at different times in the Medieval and later period is now clear. Given the high significance of the Tuquoy mortar study for our understanding of the development of this culturally important site, and as a prelude to more general publication of the wider archaeological project, a further investigation of selected samples from the mortar assemblage is now being undertaken through a range of geoscientific techniques. This paper presents emerging evidence from a comparative petrographic, SEM-EDS and XRD study designed to further characterise these various mortar materials, and challenge those previous interpretations of contrasting building lime sources. Like most environmental archaeological investigations, this study is essentially concerned with interpreting the depositional histories of surviving materials, but with a particular focus on establishing the distinction between (anthropogenic) kiln relict and (natural) added temper mixtures when both contain biogenic and geogenic clasts.

KW - Shell-Lime

KW - Maerl-Lime

KW - Petrography

KW - Archaeology

KW - Medieval

M3 - Abstract

SP - 107

EP - 107

ER -