All about copper study of the metallurgical technology of the Thule period in the Coronation Gulf re

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All about copper study of the metallurgical
technology of the Thule period in the Coronation
Gulf region

• Geneviève Treyvaud, étudiante au Doctorat,
  Département dhistoire, Université Laval

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The Archaeometalurgy

• The technologic context
• The corpus study
• The worck hypothesis
• The methodological research
• The analysis
• The results

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Copper Inuit
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The copper and alloys

• Ductile and resistance of the corrosion
• Conception and shaping of decoratives and usuals
  objects
• The native copper objects must contain a minimum
  of 99,3 of metal
• An object containing between 96 and 99,3 of
  copper is considered an alloy
• The copper can be shapped by either cold or hot
  hammering or by primary metalurgy

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Hypothesis

• The first hypothesis suggested is that during the
  late prehistoric period, all of the objects
  composed of different kinds of metals were made
  from native metal they were worked by meteoric
  iron or copper which was extracted and worked.
  The artisans are very flexible and create a great
  majority of their products composed of metals
  tailored to their needs and requests.

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• The second hypothesis is that it is simples and
  more economical because of the energetic supply
  of the metal to extract the raw material directly
  from the deposit and create on the site the
  different objects to be transformed.

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• The third and last hypothesis is in sink with the
  first two primary hypothesis that would show that
  during the European contact, the rapid diffusion
  of manufacturing alloys which came from Europe
  permitted the Inuit to upgrade and perfection
  their technological process, to uniform their
  tool productions and create a new form of
  exchange against the European merchandise.

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The methodological research

• The technology analysis of copper and alloys
• The variations of this technology through times
• The technological adaptation of the europeans
  alloys during the contact period

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The study corpus

• NaPi-2, 27 artefacts
• MkPk-2-3-11, 67 artefacts
• NcPf-1-12, 3 artefacts
• NkRh-3, 5 artefacts
• OdPc-1-2-5, 13 artefacts
• MkPj-7, 1 artefact
• NdPd-1-2, 13 artefacts
• Total 129 artefacts

Ulus, arrow points, spear points, harpoons,
hooks, punchs, burins, knifes, needles,
bracelets, rivets, wires, bars, fragments
The 129 objects studied were treated at the
analysis as technological whole
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Analysis plan

• The physico-chimics analys allows the study of
  the metals en alloys used.
• The optical observation and the metallography
  gives some informations on the material and the
  treatments of the making of the object.
• The radiology gives informations on the
  metallurgic status of the metal or alloy and also
  on the procedures used by the artisans.
• The experimentations re-create the procedures of
  the transformation of the metal in object and
  also allow the elaboration of reference sample.

The data for each artefacts are inscribed on a
analysis card created for this project.
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Identification by products of the corrosion of
the copper
Le tableau initial comporte 35 éléments
identifiables, Jambor et al.(1996) Massey
(1973) Richardson (1993) Scott ( 2000 et 2002)
Nodule de cuivre natif
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Metallurgic composition by corrosion analysis
129 artefacts
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Metallography

• Identification of the making
• Sense of the making
• Treatment fo the metal
• Identification of the stress tied to the shaping
  or to the natural inclusions

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Amalgam versus Matrix
124 artefacts
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pression
sens
Amalgame
matrice
PROFIL
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Abattement par martelage
Stress de formation
Chanfrein obtenu par polissage
Martelage en deux étapes bidirectionnels
Détachement de couches
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Indication on the usage

• Allow to put in evidence the technological groups
• Gives the degree on the metal usage
• Shows the specific surface total surface in
  cm²/ weight in g
• Example 1- 0,05 to 1,3 low usage
• 2- 1,3 to 2,65 medium usage
• 3- 2,65 to 4 high usage

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Usage categories

• Maximum usage of the metal
• Deformation
• Transformation
• Ténacity
• Resistance
• Force of cohésion

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The energetic indication

• Energy
• J xgr J/g écart de température
• Ex 4,3 gr 0,393 685C 1157,58J
• 0,393 chaleur massique moyenne
• 685 700-15
• Combustible bois flotté, north willow, spruce

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The MkPj-7-1 case ?.......
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The technologie on the MkPk-3 site

• Operating chain completed for the points and
  burins.
• The points follows a central line on the making
  by directional hammering.
• Fabrication of plaques by amalgam and diffuse
  hammering, ulus, bracelets.
• Fabrication of preforme for rivets.
• Fabrication of spurs.
• Shining and sharpening.

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A special case...the pendant
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DcEs-1 Chicoutimi.Ville de Saguenay

• Situer à lembouchure de la rivière Chicoutimi
• Plusieurs interventions archéologiques
• Une occupation préhistorique Archaïque et
  Sylvicole
• Un poste de traite
• Et du cuivre

DcEs-1
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Exemple du travail du cuivre au Saguenay
Couteau DcEx-1-87.7760
Traces de découpage
Traces daffûtage
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Pointe DcEs-1
Traces de martelage
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Découpage au ciseau
DcEs-1-1157
Découpage
DcEx-1-87.5634
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DcEs-1-1157
Traces de découpage
Traces des anciens emboutis
Traces de polissage
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Avranna, Jenness 1918
Remerciements Adrian L. Burke, Département
danthopologie, Université de Montréal Linda
Gullason, Département danthropologie, Université
de Montréal Réginald Auger, CELAT, Université
Laval Musée des Civilisations