Skeleton Plotting Absent and False Rings


How to mark ring-growth anomalies on a skeleton plot:
  • Missing Ring:
    • Sample at left didn't have a ring for year 1905 of the chronology (index value of 0.0)
    • A dashed mark is drawn on the skeleton plot between the 19th and 20th lines
    • Try This: Move skeleton plot one position to the right

  • False Ring
    • Sample at right had a false ring for year 1925 of the chronology (index value of 2.0)
    • Diagonal marks are drawn on the skeleton plot on the 39th line
    • Try This: Move skeleton plot one position to the left
Good idea: Hit the "Try again" button to see more examples

When you try skeleton plotting for yourself, you can turn on or off ring-growth anomalies:
  • There will be square options for absent or false rings, as on the right
    • Check one or both options to allow these growth anomalies
    • Un-check the options to disallow these growth anomalies
    • Mouse click the "Restart" button
  • Important point #1: With options checked:
    • Ring-growth anomalies are only possible, not for certain (just like in real life!)
    • Mouse click the "Hint" button to learn if your new core has ring-growth anomalies
    • Mouse click the "Hint" button again to hide the hint
  • Important point #2:
    • When there are absent/false rings, include their dates when you find the dates
ring-growth anomaly options



Paul R. Sheppard
Laboratory of Tree-Ring Research, The University of Arizona
Tucson, Arizona 85721 USA
office: (520) 621-6474, fax: (520) 621-8229
Comments to: sheppard@ltrr.arizona.edu