Calibrating tree-ring timelines

Tree-ring data from geographically disparate growth regions help uncover the precise age of wood used in the Mediterranean in the Bronze and Iron Ages, according to a study. Tree-ring records gathered from structural timbers can support archaeological records and offer insight into past climatic variations. Charlotte Pearson and colleagues used two approaches to date a collection of wooden timbers from the ancient East Mediterranean, an area including Turkey, Greece, and Egypt, to enable the rings to be fixed to specific calendar points rather than relative time periods. The study used measurements of radiocarbon in 186 consecutive single tree-rings from an ancient juniper timber compared with patterns of similar measurements from Irish oaks and North American bristlecone pines representing the calendar-dated period 1700-1500 BC. The comparison resulted in a permanently fixed date range for the sequence that was then refined to within a year of a calendar date using other tree-ring associations. The authors also found an anomalous change in calcium levels in the juniper rings around the year 1560 BC. According to the authors, further investigation of the anomalous change could yield clues to help pinpoint an exact date for the eruption of the Thera volcano.

Article #19-17445: “Securing timelines in the ancient Mediterranean using multiproxy annual tree-ring data,” by Charlotte Pearson et al.

MEDIA CONTACT: Charlotte Pearson, University of Arizona, Tucson, AZ; tel: 1-520-621-0807; e-mail:

[email protected]

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