Scientific Tools for Probing the Past

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Sven Isaksson Archaeological Research
Laboratory Department of Archaeology and
Classical Studies Stockholm University
Scientific Tools for Probing the Past
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• Archaeology and Chemistry
• Why a little chemistry is useful to
  archaeologists
• The archaeological sources are material remains
  chemistry is the study of matter and its change
• Material remains are affected by the ravages of
  time what is left and how it is preserved
• Man has always made use of matter and changed it
  Man the Chemist

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History C. 1800, first chemical analyses 1896,
first physical analyses 1945? New techniques in
chemistry, physics and biology 1949,
14C-dating 1970? Increased application in
archaeology 1985? Break-through in organic
analyses
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Archaeological Research Laboratory
Established in 1976 Professorship in 1986,
first as an adjoining position but later as a
regular chair, in laboratory archaeology (swe
laborativ arkeologi) Since 2005 part of the
newly created Department of Archaeology and
Classical Studies
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Department of Archaeology and Classical Studies
Classical Studies
Numismatic Research Group
Archaeological Research Laboratory
Osteoarchaeological Research Laboratory
Archaeology
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Scientific tools are used to probe the
archaeological material for more data
Archaeology!
Not Archaeology?
Not science?
Science!
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The Fate of Finds

• Excavation
• Semi-stable equilibriums are broken,
  collection, registration
• Recording
• Cleaning, visual characterization
• Conservation
• Halt decomposition, extract information
• -excavation on microscopic level
• Storage
• Keep, preserve, display
• Scientific analyses?
• Excavations on molecular or atomic level

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The nature of archaeological material
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Contamination during excavation
Hawaiian Tropic (coconut oil, UV-block).
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Contamination during recording
Day Cream (palm-tree oil etc)
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Contamination during conservation
From Aveling 1998
Paraffin
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Keeping in museums
Ancient horse DNA from Birka
Excavated aDNA mtDNA HTG10 HTG8 Late
1800-tal - - Late 1900-tal From
Götherström 2001
Alkanoic acids in Norwegian organic residues
Is organic residues better off in the ground than
in the museum?!
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Analytical techniques Prospecting Dating Cha
racterization
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Prospecting Site locating
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Prospecting Site locating Site investigating
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Prospecting Site locating Site
investigating Detecting anomalies from natural
background
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Prospecting Site locating Site
investigating Detecting anomalies from natural
background Geochemical e.g. phosphate Geophysi
cal e.g. slingram, magnetometer and ground
penetrating radar
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Nutida kyrkan
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Nutida kyrkan med tolkningen av katedralens
utsträckning
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Undersökningsytorna
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 0 -0,6 m djup
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 0,2-0,8 m djup
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 0,5-1,1 m djup
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 0,7-1,3 m djup
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 1,0-1,6 m djup
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 1,2-1,8 m djup
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 1,4-2,1 m djup
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 1,7-2,3 m djup
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 1,9-2,5 m djup
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 2,1-2,8 m djup
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 2,4-3,0 m djup
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Modellering efter georadar-prospektering Gamla
Uppsala kyrka
Reflexer på 2,6-3,2 m djup
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Dating To fix an event along a time axis
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Dating To fix an event along a time axis But
what event?
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Dating To fix an event along a time axis But
what event? The event dated by an analytical
technique is not always the same as the
archaeological event
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Dating
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Dating
Method Material Range (yrs) Sample
size Chronological Find combination artefacts 10
6 - Dendrochronology wood 104 100
treerings Magnetic TRM burnt clay 104, or
longer cm DRM sediment Radiation
damage Fission tracks glass, mineral 102107 mm
TL ceramic, br. stone 102105 mgg OSL sedime
nt 106 mgg ESR enamel 103106 mgg Radioact
ive decay Conventional 14C organic 50 000 10
g Accelerator 14C organic 70 000 mg K/Ar mine
ral 105109 g Physical phenomenon Hydration ob
sidian, glass mm Chemical reactions Racemisatio
n bone, hair 102106 g Biological
growth Lichenometry lichens
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Characterization Provenance Biological
origin Technology Man Living conditions and
Climate
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Provenance
Heterogeneity of the Earths crust Materials
collected from a certain deposit may have a
specific composition Mineral (stone, clay),
metal, slag, glass
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Provenance Flint
Provenance of 70 of flint axes identified by
trace elements alone Together with archaeological
data, e.g. context and date, 95 identified
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Provenance Garnets
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Biological origin
Squalene
Stigmasterol
Cholesterol
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Biological origin
Chemical analyses of Fats/Oils Waxes Pitches Tars
Leather Textile Food Morphological
analyses Seeds Leather Fur Textile Bone
Short-chain fatty acids
Long-chain ketones and DAG
Long-chain fatty acids and MAG
Triacylglycerols (TAG)
Sterols
Gas chromatogram of lipid residues
IR-spectra of organic residues
Scanning Electron Micrographs of cells from
barley and pea in prehistoric food residue
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Technology Deposit or Inlay?
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Technology Deposit or Inlay?
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Technology Just because its green doesn't mean
its bronze
(Stjerna 1997)
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Technology Symbols or Cymbals the Fröslunda
shields
From a sulfide ore - late Bronze Age Hammered
and annealed not suitable as cymbals Flattening
of slag inclusions hammered from a piece 15 cm
in diameter
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Man
Diet C- and N-isotopes, trace
elements Breast-feeding N-isotopes Sex
determination Osteology, aDNA Kinship aDNA Migra
tion aDNA, S- and O- isotopes, trace elements
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Living conditions and climate
Disease Osteology, aDNA Climate O-isotopes Veg
etation, regional Pollen analysis Vegetation,
local Plant macro fossils, organic
geochemistry
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Facilities

• aDNA laboratory for extraction and PCR, post-PCR
  laboratory in separate building
• Atomic Absorption Spectrophoto-meter for trace
  metal element analyses of soil, bone and
  artefacts
• Field-archaeology equipment, incl. sampling
  probes, field spectrophotometer, metal detector,
  GPS, total station, photo-tower for analogue or
  digital cameras
• Fourier Transform Infrared Spectrometry for
  analyses of organic residues and pigments

• Freezer-room for the storage of very large
  samples, e.g. whole graves
• Gas Chromatography and Mass Spectrometry for
  organic residue analyses
• GIS computer systems for spatial analyses
• Mass Spectrometry for isotope (C, N, S, O)
  analyses primarily of bone collagen
• Microscopes and sample preparation equipment for
  analyses of archaeo-botanical materials,
  textiles, etc

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Facilities

• Slingram, Ground-Penetrating Radar and
  Magnetometer for archaeological prospecting
• Spectrophotometers for wet-chemical analyses
  (e.g. phosphates)
• Variable Pressure Scanning Electron Microscope
  with Energy Dispersive X-ray Spectrometry for
  microstructure and elemental analyses
• X-Ray Diffraction for the analysis of minerals,
  bones and pigments

• Microscopes and sample preparation equipment for
  microstructure analyses of metals and ceramics
• Microwave Accelerated Reaction System for rapid
  sample preparation, i.e. extracting, digesting,
  dissolving, hydrolysing or drying organic or
  inorganic materials
• Optical 3D-scanner for both high-resolution
  surface analyses of artefacts and for large-scale
  3D documentation
• Preparation and conservation laboratory primarily
  for metal artefacts

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Research programs

• Svealand in the Vendel and Viking Period
  (finished)
• Forts and Fortifications in the Mälaren Region AD
  400-1100 (finished)
• Us and Them Cultural identity in the Middle
  Neolithic
• Bread for the dead, bread for the living
  Cereal-based food in the Late Iron Age
• By House and Hearth The chemistry of culture
  layers as a document of the subsistence of
  prehistoric man
• Tracing Ancient Vegetable Food Chemotaxonomy of
  plant lipid residues
• Gender and Diet in the Neolithic