What is tree ring dating
The measured ring width data were used to develop a chronology for the buildings that was then correlated against other absolutely dated tree-ring chronologies from the region.
The strong correlation among the ring width time series from both structures provided evidence that the trees from which the logs were cut grew contemporaneously in the same area.
Dendrochronology is the science or technique of dating events, environmental change, and archaeological artifacts by using the characteristic patterns of annual growth rings in timber and tree trunks.
Dendrochronology is used in radiocarbon dating to calibrate radiocarbon ages.
A new layer of wood added in each growing season, thickening the stem, existing branches and roots, to form a growth ring.
The outer portion is the "late wood" and has sometimes been termed "summer wood", often being produced in the summer, though sometimes in the autumn and is denser.
Dendrochronological (calendar) dates can be matched with ages to calendar years.
Beyond the limit of the absolutely dated tree ring sequence, calibration becomes more problematic (Reimer et al., 2009; Bronk Ramsey et al., 2006; Mellars, 2006a; Mellars, 2006b; Turney at al., 2006; Blockley and Housley, 2009).
Powhatan State Park contracted with the University of Arkansas Tree-Ring Laboratory to develop a more accurate dating and interpretation of the log structures.Panels were trimmed of the outer rings, and often each panel only uses a small part of the radius of the trunk.Consequently, dating studies usually result in a "terminus post quem" (earliest possible) date, and a tentative date for the actual arrival of a seasoned raw panel using assumptions as to these factors. A portrait of Mary, Queen of Scots, in the National Portrait Gallery, London, was believed to be an 18th-century copy.While dendrochronology has become an important tool for dating oak panels, it is not effective in dating the poplar panels often used by Italian painters because of the erratic growth rings in poplar.The Fairbanks House, Dedham, Massachusetts, had long been claimed to have been built circa 1640 (and being the oldest wood-framed house in North America), core samples of wood taken from a summer beam confirmed the wood was from an oak tree felled in 1637–8.