1 Dendrochronological Reconstruction Dates –Relative sequence –Absolute dates –Errors in archeological interpretation Behavior –Construction habits Environment –Climate in the past

2 Dendrochronology Dating Does date of wood sample = construction date?

3 Outer date predates construction event –Collected dead tree –Collected a bunch of trees, stockpiled –Reuse a beam from old house 14 th century log used in 1929, Oraibi –Large sites versus distinct sites Outer date postdates construction event –New log put in during repair –Problem or solution? Could date repair sequences Archeological Interpretation of Dates

4 Date Clustering Saves the Day Given lots of dates, the date of construction event will be the best cluster of dates –Most frequent date

5 Kin Endeschee

6 Date Clusters Skewed beginning: slow development of site Steep ending: fast abandonment Early dates may be stockpiling, re-use Late dates may be repair beams Requires a lot of dates, replication

7 Cutting Date or Not? Outermost ring was when tree died Evidence of cutting date: –Bark, best but not common –Complete outer ring –Beetle galleries –Dark patina veneer

8 Non-cutting Dates Some number of outer rings lost –Erosion –Shaping –Burning What to do? –Estimate # of outer rings –Admit non-cutting and leave it –Rely on clustering

9 Behavioral Characteristics Type of cutting devices –Fire –Stone axes –Metal axes Repair schedules Stockpiling, cooperation

10 SW Archeology Sequence Chaco Anasazi: abandoned by –Start of a long period of drought

11 SW Archeology Sequence Mesa Verde Anasazi: abandoned by 1280s –In period known as Great Drought

12 SW Archeology Sequence Kayenta Anasazi: Betatakin, Keet Seel begun by 1250, abandoned by 1300 –Perhaps affected by arroyo formation