Example Application of Crossdating

After crossdating, dendrochronologists can:
  • Assign the true year of formation for every ring of each sample
  • Analyze past environmental and/or human events.
  • For example, see image to right:
application of crossdating
old dead wood
© J.D. Speer
Living tree sample: Chronology from living trees:
  • Photo: Ponderosa pine in Oregon
  • Known bark date (e.g., the present year) is starting point
  • After crossdating samples from living trees, dendrochronology extends back in time, e.g., AD 1500.
old dead wood
© H.D. Grissino-Mayer
Dead wood sample: Chronology from dead trees:
  • Standing snags or fallen logs, like this ponderosa pine remnant in New Mexico
  • Lived for a long time and died long ago
  • If dead trees lived concurrently with the living tree chronology:
    • Outer growth of dead trees crossdates with inner portions of living trees
    • Dendrochronology extended further back in time, e.g., AD 1200.

sampling at Tonto Ruin
© H.D. Grissino-Mayer
Dendroarcheological sample: Chronology from archeological samples:
  • Wooden beams, uprights, and other structural parts of ruins like the Tonto Ruin, Arizona
  • If archeological samples lived concurrently with the dead wood chronology:
    • Outer growth of structural samples crossdates with inner portions of dead trees
    • Dendrochronology extended further back in time, e.g., AD 800
    • Past human behavior reconstructed and analyzed

Pattern Matching | Sensitivity | Example Application | Master Chronology | Introduction | Relative Scale