Dendrochronological Dating

Mineralised archaeological wood was examined with Micro and Sub-micron XCT.Non-destructive anatomical and dendrochronological analysis were evaluated.Wood remains in a block of soil could be identified as oak and dated.Anatomical features of a beech grid of an Early Medieval sword could be visualised.XCT analysis depend on the achieved resolution which is linked to the sample size.The analysis of archaeological wood is of great importance in historical research because of its status as an outstanding information carrier. Dendrochronology, in particular, is an important method for dating and provenancing; but applied in the conventional way it would, in most instances, require a large interference with the object. X-ray Computed Tomography offers a non-destructive technology for the analysis of ring widths while at the same time enabling wood species identification, which is essential for dating. The technology was tested on two specific cases: firstly, on wood block-lifted together with the surrounding soil and other objects and, secondly, on wood preserved through mineralisation on iron objects. Both micro- and submicron-computer tomography scanners were employed for these tests. The results demonstrate that it is possible to perform wood species identification based on reconstructed CT-scan images, under certain conditions even in soil blocks, and that ring widths can be measured. The results are dependent upon the resolution and contrast that can be achieved in a measurement which, apart from the characteristics of the scanner, is affected by both object size and wood species.

Highlights

- We re-investigated the timbers of three Roman ships excavated along the Dutch limes.
- We used the content of the tree-ring repository DCCD to determine wood provenance.
- We created a natural distribution map of oak to interpret geographical results.
- We show that the ships were built in the lower-Scheldt region of Gallia Belgica.
- Inland navigation routes connected this region to the limes of Germania inferior.

The current study presents the results of the first dendrochronological survey performed over the East Aegean island of Symi. Research Highlights: Dendrochronological research of the East Aegean region is of paramount importance since dendrochronological data from the region, and especially the islands, are still limited. Background and Objectives: The main aim of the study is to explore the dendrochronological potential of the island, focusing on the dating of historical wood and buildings as well as dendroprovenancing. Materials and Methods: A total of 57 wood samples were collected from historical timber from windmills and architectural elements, including doors and warehouse planks, while 68 cores were collected from the three dominant tree species of the island-Cupressus sempervirens, Pinus brutia, and Quercus ithaburensis subsp. macrolepis-in an attempt to develop local reference chronologies that could be useful in dating historical timber Results: Of the historical timber, at least nine different species have been detected, with conifers representing the majority of the collected material. In total, 56% of the dendroarchaeological samples, belonging to four different species, were dated absolutely. According to cross-dating and dendroprovenancing results, Pinus nigra, Cedrus sp., and Quercus sp. represent timber imported from present-day Turkey while the fir samples collected from the windmills originate from Central Europe. The use of local timber is also highly probable although it could not be confirmed by the reference chronologies developed for the three dominant tree species of the island. Conclusions: The results of the study reveal the dendrochronological potential of the island from both dendroarchaeological and dendroecological perspectives. The finding that most of the wood was imported mainly from Turkey highlights the importance of timber trade with the Turkish mainland during the mid-18th and 19th centuries. Chronologies developed from living trees could be used in future studies for dating historical material while further research would increase our understanding of past timber trade and the island's history.

Long Bosnian pine chronologies from different mountains are shaped by different climatic parameters and can help identify past drought events and reconstruct landscape histories. Abstract We developed a 735-year-long Pinus heldreichii chronology from the southern distribution limit of the species, expanding the available database of long Bosnian pine chronologies. Tree-ring growth was mainly positively correlated with growing degree days (GDD: r 1950-2018 = 0.476) while higher temperatures during both winter and growing season also enhanced growth (T WT : r 1950-2018 = 0.361 and T GS : 0.289, respectively). Annual precipitation, during both calendar and water years, had a negative but weaker impact on annual tree growth. The newly developed chronology correlates well with chronologies developed from the neighboring mountains. The years with ring width index (RWI) lower than the average were found to correspond to cool years with dry summers. Still, the newly developed chronology was able to capture severe drought events, such as those in 1660, 1687, and 1725. Several old living trees had internal scars presumably caused by fires. Therefore, old mature trees could be used for fire history reconstruction in addition to climate reconstruction. Although the presence of lightning scars indicates an important natural agent of fire ignition, human activities associated with animal grazing could also be an underlying reason for fires in the region.

A dendroarchaeological survey of a traditional Nuu-chah-nulth plank house at Kiix?in, the former capital of the Huu-ay-aht First Nations, on the west coast of Vancouver Island British Columbia, was undertaken in the summer of 2002.Standardized dendroarchaeological techniques were employed to collect and analyse increment core samples collected from the house known as Quaksweaqwul.Floating ring-width series were compared to a locally prepared Western redcedar (Thuja heterophylla) master tree-ring chronology (1511–2002 AD) to determine when the trees used to construct the house were felled.The findings of the survey indicate that Quaksweaqwul was built after the 1835 AD growth year.As the amount of perimeter wood loss due to weathering and preparation is difficult to ascertain, no precise felling or construction date can be presented.
The results of this survey provide insights into Huu-ay-aht First Nations history and offer direct evidence for the general state of preservation of individual house posts and beams at Kiix?in.Additionally, the successful dating of a traditional First Nations village using a dendroarchaeological approach highlights the potential this technique may hold for developing similar insights at other sites along Canada’s Pacific Coast.

The scientific meeting in Ohrid is part of the international project ‘Network in Eastern European Neolithic and wetland archaeology for the improvement of field techniques and dating methods’ in partnership with University of Bern (Switzerland), State Hermitage Museum (Russian Federation), Taras Shevchenko National University (Ukraine) and Center for Prehistoric Research (Republic of Macedonia). This project is supported by the Swiss National Science Foundation which also funds the participation of delegates within the scientific meeting in Ohrid. Therefore, this event will be an excellent occasion for the implementation of project aims and a significant contribution in the promotion of latest knowledge and practices in wetland archaeology and dating methods.