Wiggle-Match Dating of Wooden Samples from Iron Age Sites in Northern Italy

Abstract

ABSTRACT. Archaeological excavations carried out at the sites of Laion/Lajen (Bolzano/Bozen) and Stufles-Oberegger (Bressanone/Brixen) in northern Italy uncovered well-preserved wooden samples in cultural layers archaeologically dated to the Iron Age. From the 2 sites, different wooden samples were recovered that were well preserved enough to allow clear identification of the tree species and of the ring structure. Among the different wooden samples, 2 were selected for radiocarbon analyses: from Laion/Lajen, a beam with an unbroken sequence of 158 rings; from Stufles-Oberegger, a combusted trunk with a sequence of 217 rings. Both samples were identified as Larix decidua species. From each sequence, single rings were selected and submitted for accelerator mass spectrometry (AMS) 14 C dating analysis at CEDAD. Conventional 14 C ages were then calibrated to calendar ages using the IntCal04 atmospheric data set, while the statistical constraints resulting from the defined ring sequence were used to develop a wiggle-matching approach by making use of the Bayesian analysis functions available in OxCal. The obtained results are an important contribution in refining the chronology of the studied sites.

The age of the olive trees in the Garden of Gethsemane

“…The calibration data set was IntCal04 (Reimer et al, 2004) for CEDAD (Calcagnile et al, 2005), and IntCal09 (Reimer et al, 2009) for VERA Laboratory. OxCal 3.10 uses a Bayesian approach for wigglematching calculations , which were performed by CEDAD (Quarta et al, 2010).…”

Resolving Time Among Non-Stratified Short-Duration Contexts on a Radiocarbon Plateau: Possibilities and Challenges From the Ad 1480–1630 Example and Northeastern North America

“…Even a few decades or more could enable useful radiocarbon wiggle-match dating which could offer key dating potential, as exploited in a range of other areas and periods (e.g. Bayliss and Tyers 2004;Galimberti et al 2004;Barfield et al 2010;Quarta et al 2010;Manning et al 2016;Hogg et al 2017;Turkon et al 2018).…”

“…Tree-ring sequenced samples which allow wiggle-match 14 C dating (Bronk Ramsey et al 2001;Galimberti et al 2004) are the most obvious solution enabling temporal resolution (for a Hallstatt period example, see e.g. Quarta et al 2010). Although, in situations where only short sequences are available in isolation, these sometimes will potentially remain problematic until calibration curve and sample resolution can be fully aligned (see Bayliss et al 2017;Jacobsson et al 2018).…”

A CENTENNIAL AMBIGUITY: THE CHALLENGE OF RESOLVING THE DATE OF THE JEAN-BAPTISTE LAINÉ (MANTLE), ONTARIO, SITE—AROUND AD 1500 OR AD 1600?—AND THE CASE FOR WOOD-CHARCOAL AS A TERMINUS POST QUEM

“…An ideal solution is where a wood-charcoal sample securely associated with a site context provides a tree-ring sequence covering several decades or more and hence potentially a specific (non-ambiguous) 14 C-wiggle-match (Pearson 1986;Bronk Ramsey et al 2001;Galimberti et al 2004;Hogg et al 2017). Analogous examples from the earlier Hallstatt 14 C plateau period include Quarta et al (2010); Jacobsson et al (2018); and Manning et al (2018b). Where available, this can provide not only a terminus post quem (TPQ) or date for the last extant tree-ring or waney edge (and cutting and use date) but, if it is sufficiently long enough to define a unique (or at least overwhelmingly likely) solution, it can resolve the previous ambiguity.…”