Dating of Alaskan Neo-Inuit architectural timbers (11-13th): wiggle-matching and oxygen isotope cross-dating
In Northwestern Alaska, well-preserved architectural timbers from coastal Neo-Inuit archaeological sites can be used to document the climatic variations and cultural transformations of the beginning of the 2nd millennium AD. In this treeless tundra environment, the main wood resource is driftwood from interior Alaskan forests, carried to the coast by major rivers and ocean currents.
Conventional dendrochronology allowed cross-dating 68 architectural timbers out of 282 archaeological Picea glauca disks from 5 coastal Neo-Inuit sites. These disks cross-date with each other and with millennium master Kobuk River chronology (AD 974-2002, Northwest AK) and range from the 11th to 17th centuries. Among the remaining 214 undated tree-ring series, 39 cross-date with each other allowing us to build 10 "floating" sequences of at least 2 individual series.
We present our attempt to combine conventional dendrochronology, wiggle-matching technique, and dendro-isotopy (oxygen isotopes dating) to annually date these floating sequences. The wiggle-matching dating of 8 archaeological cross-sections belonging to 5 floating sequences (based on 75 radiocarbon dates) allows us to constrain as closely as possible the calendar interval of each dated disk last growth ring, which correspond to a “plateau” period of the radiocarbon calibration curve. At the same time, we are cross-dating 3 of the wiggle-matched cross-sections with our newly built oxygen sequence based on 5 of the 68 cross-dated timbers.
Combining 14C and δ18O approaches allows us to increase annual chronological and calendar information about Neo-Inuit sites in Northwestern Alaska and develop preliminary tree-ring referential for cross-dating other Neo-Inuit architectural wood.