Neutron Activation Analysis to Determine the Origin of Pottery Sherds

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					    Neutron Activation Analysis to
Determine the Origin of Pottery Sherds
              Our Investigation
What was the relationship between large, urban
 centers and smaller agricultural villages like
 the one at Pulltrouser Swamp?

  Methods-
• Sample Cataloguing
• Sample Preparation
• Sample Activation
  – Irradiation and Counting
• Sample Analysis
       Irradiation and Counting
•   Looked for certain elements: Co, Fe, Sc, etc.
•   Following irradiation, 5000-second count (live time) of each
    sample after a 1-week decay period, and a 10000-second count
    (live time) after a period of 4 weeks decay, using a 30% efficiency
    HPGe detector.
•   Explanation of equations used:
      Absorption of Neutron:

    1n + Ax  A+1x (radioactive)
      Beta Decay:

    n p + v + β[+γ]
      Standard Deviation:

    SD = sqrt{ sum(xi – xAvg.)^2 / (n-1) }
      Range:

    Mean +/- 2SD
Data and Results
 Final Analysis and Deductions
• Achote Black samples are not similar to the
  redware found at Nohmul
• Mt. Pine Red samples, excluding sample
  KAX_005, have a 95% probability of being
  similar if not the same as the samples from
  Nohmul
• Because KAX_005 does not match the Nohmul
  samples on some elements, it is possible that
  the villages at Pulltrouser Swamp traded with
  other villages and regional centers.
 Future Areas for Investigation
• Find samples from other villages and
  regional centers near Pulltrouser Swamp
• Put samples through NAA process and
  Direct Comparison
• This would determine if the village at
  Pulltrouser Swamp traded with other
  villages besides Nohmul
  Connections to Bigger Picture
• Gives more
  understanding of
  Mayan Civilization
  – Introduction of
    Swidden agriculture
    gave Pulltrouser
    Swamp an excess in
    food
  – Pottery more valuable
    than food, so tribute
    could be issue

				
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posted:2/6/2012
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