Dendroarchaeology

""CE CHAPITRE regroupe l’ensemble des informations tirées de l’analyse des charpentes de notre corpus, menée conjointement sous le regard archéologique et dendrochronologique. Dans cette perspective, cette publication constitue la première approche dendro-archéologique pour l’époque médiévale en France. Cette nouvelle discipline, qui permet d’optimiser au maximum l’information conservée par le matériau-bois, nécessite l’implication des questions archéologiques dans la réflexion dendrochronologique, et réciproquement, la dendrochronologie se doit d’intégrer les observations archéologiques, de même que l’apport des textes anciens. Dans cette vision, il est bien évident que la dendrochronologie, aussi précise soit-elle, ne peut se résumer à une simple datation, comme c’est malheureusement souvent le cas. En revanche, si l’on veut apporter localement des éléments de réponse aux questions du potentiel forestier et suivre les étapes successives de la préparation des bois, de la gestion sylvicole au transport des bois au chantier, il est indispensable de disposer au préalable :
– de relevés archéologiques exhaustifs et critiques des charpentes et des bâtiments étudiés, incluant la mise en évidence des phases de construction, des reprises et des éléments réemployés ;
– des mensurations et des descriptions morphologiques et physio- logiques précises des bois architecturaux ;
– d’un relevé des indices de mise en œuvre des structures (marques, traces d’établissage, indices de levage, sens du chevillage, orientation des mi-bois...).
Cette recherche sous-entend qu’un temps énorme doit être consacré à l’analyse des données, mais aussi et surtout au terrain. On ne peut donc pas prétendre réaliser à la fois l’ensemble de ces observations et le prélèvement des échantillons dendrochronologiques en une ou deux journées, de même qu’on ne pourra prétendre faire une étude de charpente sur la seule lecture des marques de charpentier. L’étude des bois normands médiévaux que nous proposons ici résume donc plus de dix ans de recherche conduite sur environ 30 édifices répartis en Haute et en Basse- Normandie, soit 49 charpentes distinctes dont on retrouvera l’essentiel des informations dans les thèses de Frédéric Épaud et Vincent Bernard. Sur ces 49 charpentes, 40 ont pu bénéficier d’une analyse dendrochronologique, réalisée le plus souvent par le laboratoire de l’UMR 6566 à Rennes, mais aussi pour quelques autres par le CEDRE de Besançon et Archéolabs de Saint-Bonnet-de-Chavagne. Ces analyses ont été financées par la Conservation régionale des Monuments historiques de Haute-Normandie, le Service régional d’archéologie de Basse-Normandie et le Centre de recherche sur les Monuments historiques.""

The 19th century was an era of increasing mechanization and globalization, which transformed maritime networks and shipbuilding in and beyond the Mediterranean. Shipwrecks offer valuable physical evidence of such maritime connectivity and evolving shipbuilding techniques but must be dated within a high-resolution timeframe to be synchronized with, and thereby enhance, historical records. We focus here on high-resolution dating of the Akko Tower Shipwreck, the remains of an Ottoman merchant brig found inside the harbor of Akko, Israel. We use dendrochronology, 14C wiggle-matching, and Bayesian chronological modeling to determine that the ship was likely constructed in the mid-1850s, and therefore called at Akko’s harbor after the town’s 1840 bombardment, a period of decline traditionally under-studied in Ottoman historical narratives. Using dendroprovenancing methods, we find that the ship’s hull used timbers from the Anatolian Black Sea region, although it was built in the French construction tradition, and used British metal rigging and fasteners, which reflect shifting Anglo-French influence and socioeconomic interconnections with the Ottoman Empire during the 19th century.

The Akko Tower Shipwreck is the first shipwreck from Israel to be dendrochronologically dated and provenanced. Our results show how dendrochronology and Bayesian chronological modeling can be used successfully not only for high-precision dating, but also for untangling the shipbuilding processes and the socioeconomic networks that made ship construction possible. We also re-evaluate East Mediterranean oak sapwood datasets and develop an approximate new sapwood model that provides more robust estimates of felling dates for tree-ring analysis of this region’s oak wooden cultural heritage.

The article presents the tree-ring chronology of the Sheksna and Sukhona river basins for the period from 1085 to 2009. It was based on the wood of living trees, architectural monuments and timbers from excavation at Kirillo-Belozersky monastery. There are sets of yearly growth of 109 samples in its structure. This is the first continuous and absolutely dated chronology of such duration on the European part of Russia which is tied to the modern age.

Geoposizionamento, rilievo, campionatura e analisi dendrocronologica delle specie arboree della foresta sommersa del lago di Tovel (TN). Con il patrocinio del Parco Naturale Adamello Brenta e del Comune di Ville d'Anaunia (TN) e la collaborazione di: CNR-IBE di S. Michele all'Adige (TN)

The article discusses the results of dendrochronological and radiocarbon dating of the tree rings of oak gravestones and elements of the coffins of the medieval cemetery in Vyazma. The result of the work is the creation of the first, for archaeological sites of the European part of Russia, absolutely dated tree-ring chronology for oak, which includes measurements of the width of annual rings of 11 samples, with a total length of 233 years (1074-1306).

This dissertation investigates how people in the northern US Southwest used clothing and representations of clothing in other media to signal aspects of social identities in the Chaco and post-Chaco eras (AD 850–1300). This was a time when communities were first organized into a large regional system and later fractured into smaller organizational entities focused at the site cluster and village levels. In the aftermath of the Chaco reorganization, social inequalities appear to have burgeoned across the greater San Juan River drainage, and not long after these developments, the entire region was depopulated. Understanding the development and transformation of identity during this pivotal period is critical for explaining the social mechanisms that contributed to the major reorganization of communities in the post-Chaco era.
To better understand identity expression during these tumultuous times, I perform technological and stylistic design analyses of attributes used to create and decorate ornately woven, twined yucca sandals, in addition to cross-media and proxemic analyses of sandal representations in building murals, rock art, and portable media. Technological and stylistic analyses show that some communities consistently made and used sandals with specific sets of attributes that expressed shared village-level identities. At the same time, other communities favored more diverse repertoires of design attributes that signaled aspects of identities shared across a much larger area. During the Chaco era, twined-sandal styles became highly variable and appear to have indicated positions in social hierarchies. During the following post-Chaco era, the stylistic variability of the sandals declined across the region and may have come to signal a leveling of the social hierarchies. In both time periods, ornate geometric designs woven into the soles of the sandals indicated the home communities or sodality groups to which their wearers belonged. Sandal imagery in rock art was placed to mark major travel routes and boundaries
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between communities that expressed shared identities. Depictions of sandals in other media closely matched their woven counterparts and show that these images were potent symbols of group affiliations and identity politics in the post-Chaco era. Although this research focuses on clothing, it also addresses broader issues of adaptation and identity, providing new information about societal disruption and reformation in the ancient US Southwest.

Ilopango volcano (El Salvador) erupted violently during the Maya Classic Period (250e900 CE) in a densely-populated and intensively-cultivated region of the southern Maya realm, causing regional abandonment of an area covering more than 20,000 km 2. However, neither the regional nor global impacts of the Tierra Blanca Joven (TBJ) eruption in Mesoamerica have been well appraised due to limitations in available volcanological, chronological, and archaeological observations. Here we present new evidence of the age, magnitude and sulfur release of the TBJ eruption, establishing it as one of the two hitherto unidentified volcanic triggers of a period of stratospheric aerosol loading that profoundly impacted Northern Hemisphere climate and society between circa 536 and 550 CE. Our chronology is derived from 100 new radiocarbon measurements performed on three subfossil tree trunks enveloped in proximal TBJ pyroclastic deposits. We also reassess the eruption magnitude using terrestrial (El Salvador, Guatemala, Honduras) and near-shore marine TBJ tephra deposit thickness measurements. Together, our new constraints on the age, eruption size (43.6 km 3 Dense Rock Equivalent of magma, magnitude ¼ 7.0) and sulfur yield (~9e90 Tg), along with Ilopango's latitude (13.7 N), squarely frame the TBJ as the major climate-forcing eruption of 539 or 540 CE identified in bipolar ice cores and sourced to the tropics. In addition to deepening appreciation of the TBJ eruption's impacts in Mesoamerica, linking it to the major Northern Hemisphere climatic downturn of the mid-6th century CE offers another piece in the puzzle of understanding Eurasian history of the period.

Timbers of boats and ships are rarely perceived and studied as a collection of individual objects rather than as a single comprehensive unit. This has been true, as elsewhere, in Egypt, where the remains of twenty-five to thirty-five functional watercraft from the pharaonic period have been excavated thus far,  ranging from fragments discernible as boat components only from context to complete (or nearly so) vessels interred in association with royal burials.  When a watercraft is analyzed as a collection of individual artifacts (compa-rable to the analysis of, for example, faunal or human remains), the resulting data can extend far beyond the scope of its construction and technology (the usual foci of nautical studies), back to events in the shipyard where it was built, up the supply-chain, and into the forests from which the timbers were harvested. Each of these stages resulted in modification(s) to the raw material. When timbers are examined with such processes and the larger cultural and environmental contexts in mind, it is possible to gain insight into human-environment interactions, including: forestry practices, responses to environmental change and variation, timber selection, stockpiling, deadwood use, timber conversion (economy of wood use), and timber supply and trade.  Through their origin, shape, size, general quality, and other features, ship and boat timbers will reflect methods of managing and acquiring wood, a “timber economy.”

During the Roman period various military structures were build along the limes in the Lower Rhine Region. These military structures were connected with a road. This road has been excavated at various locations. One construction phase of the limes road and related structures was dendrochronologically dated to the autumn or winter of AD 124–125. This phase is probably related to a visit of emperor Hadrian to the region. The dendrochronological material of all contexts from this period shows a striking similarity of the tree ring patterns. This indicates that the wood came from a single region. This region is thought to have been located on the coarse soils between Xanten and Venlo. The timber was thus transported over a distance of approximately one hundred kilometres, making this the earliest example of large-scale long distance timber transport in the Lower Rhine region. The scale of the project justifies the assumption that the Roman state and army were involved. The oaks were most likely transported over water using barges. It should be noted that local wood was also used, indicating that the local woodlands were not yet depleted, but for this large-scale project the Roman army also had to look elsewhere for resources.

Timbers from the settlement of Lusatian culture in Biskupin (North-Western Poland), located on the small peninsula on Biskupin Lake, hold a unique biologica! archive of information from the tum of the Bronze Age to the Iron Age. In 1993 the first tree-ring data was decoded and an absolute construction date was established at 747-722 BC (Ważny 1993, 1994). These results differed by 100-250 years from the working dates of the archaeologists using traditional methods.
The 70th anniversary of the discovery of the Biskupin settlement provided an oppor-tunity to take a new series of samples for dendrochronological study with the aim being to date precisely the phases of building activity as well as to answer the questions: when and why the settlement was abandoned? Sixty-five wood slices from the south-western sector (Fig. 1 ), mainly oak, delivered 61 new dating results (Fig. 2), increasing the total number of dated samples to 120. Dating results are confirmed by statistical tests based on north-European oak chronologies (Fig. 3 and 4). The time interval of confirmed building activity has been extended from 25 to 43 years, with the oldest timber from the new series originating in 7 50 BC, the youngest in 708 BC. While both of these dates define the time limits of building activity, the vast majority of trees were cut in 739-736 BC, dur-ing which time a feverish building program covered 1.5 ha with houses, streets, fortifica-tions, etc., displaying the technical and organizational skills of the Biskupin settlers.
Only six timbers were dated to „ 7 30 BC and after". This low number suggests repairs and necessary replacements rather than planned rebuilding or reconstruction. We know that the settlement was preserved only because it was submerged. Even as durable as oak is, in the extremely wet conditions of the peninsula on Biskupin Lake, based on contem-porary reconstructions wooden construction can last only a dozen or so years. The Southwest German pile-dwellings functioned in similar environmental conditions, and because of the existing biodegradation factors, their exposed wooden elements were not even as durable as at Biskupin. Based on the distribution of the years of repairs Billamboz (2008) estimated that the life span of the constructions did not exceed a few years. We speculate therefore that Biskupin was abandoned around 708 BC.
The results of the tree-ring dating of Biskupin timbers have been compared with the first dating results obtained for neighboring settlements in Izdebno and Sobiejuchy. Both are located within a radius of 15 km from Biskupin. Thirteen dating results obtained for Sobiejuchy demonstrate that this settlement functioned simultaneously with Biskupin. The only one tree-ring dating for the Hallstatt period in Izdebno (,,around or after 729 BC") is also close to that of Biskupin constructions. Slightly younger is Ostrowite Trzemeszeńskie, located ca. 40 km south of Biskupin, which is dated to ,,around or after 706 BC".
The Biskupin timbers saved records of strong environmental changes in their tree--ring structures. The Biskupin oak chronology shows remarkable periods of growth reduction (Fig. 5). The longest growth disturbances occurred in the years 857-844 BC, 792-782 BC and after 745 BC. They are compatible with observations of growth dynamic and generation changes of bog-oaks growing in Lower Saxony (Leuschner 1992). The youngest Biskupin timber was cut from an oak tree displaying distinct symptoms of die-back that are visible in tree-rings formed after 720 BC (Fig. 6). At the same time ( 71 7 -712 BC) in the mi res in NW Germany solid trackways were built. They are situated exactly at the border of two different peat layers, what Schmidt ( 1992) interpreted as evidence of a considerable rising groundwater level at that time.
The Hallstatt period is characterized by a sudden climate change caused by reduced solar activity. Based on the rise of atmospheric Cl4, van Geel (1998) dated climate change for between 850-7 60 BC. Interpretation of bog deposits indicates a rapid transition from a relative dry and warm climate to wet and cold climatic conditions. Swindles et al. (2007) suggest that climatic response to a decline in sun activity could be delayed by up to 100 years in some regions of Europe. The Late Bronze Age farming communities of Northern Europe translocated centers of their activity to survive the deteriorating climate conditions (Tipping et al. 2008). The results of a sudden and strong climate change probably influenced the decision to settle the peninsula at the Biskupin Lake, because of the natural defenses of being surrounded by water. Climate change also caused the abandonment of the settlement because of the still rising water levels. According to Niewiarowski ( 1995) the water level in the lake couldn't have been higher than 77.5 m.a.s.I. at the time when the peninsula was settled. Then the water table in the lake rose by 2 m, when a crossing of the level of 79 m.a.s.l. would have caused flooding of almost the entire peninsula In face of the absence of any written sources, reconstruction of the history of the settlement of the Lusatian culture in Biskupin is dependent on the sciences, among others on the archive records saved within the „hard wooden discs".

This study presents, for the first time, an environmental reconstruction of a sequence spanning nearly the entire Mediterranean Epipaleolithic (~22.0e11.9 ka cal. BP). The study is based on a well-dated, highresolution pollen record recovered from the waterlogged archaeological site Jordan River Dureijat (JRD), located on the banks of Paleolake Hula. JRD's continuous sequence enabled us to build a pollen-based paleoclimate model providing a solid background for the dramatic cultural changes that occurred in the region during this period. Taxonomic identification of the waterlogged wood assemblage collected from JRD was used to fine-tune the paleoenvironmental reconstruction. The chronological framework is based on radiocarbon dating and the typology of archaeological findings. The LGM (~22e19 ka cal. BP) was found to be the coldest period of the sequence, marked by a distinct decrease in the reconstructed January temperatures of up to 5 C lower than today, while mean annual precipitation was only slightly lower than the present-day average (~450 vs. 515 mm, respectively). The wettest and warmest period of the record was identified between~14.9 and 13.0 ka cal. BP, with maximum values of 545 mm mean annual precipitation reached at~14.5 ka cal. BP. This time interval is synchronized with the global warm and moist Bølling-Allerød interstadial as well as with the onset of the Natufian culture and the emergence of sedentism in the Levant. The Younger Dryas began around 12.9 ka cal. BP and was identified as an exceptional period by the JRD sequence with low temperatures and minimal climatic seasonality contrast: an increase in rain contribution during spring, summer, and autumn was documented concurrently with a significant decrease in winter precipitation. The detailed vegetation and climatological reconstruction presented in this study serves as backdrop to seminal events in human history: the transition from small nomadic groups of hunter-gatherers to the sedentary villages of the Natufian, eventually transitioning to the agricultural, complex communities of the Neolithic.

In 1980 Ernst Hollstein published his Central European Oak Chronology, which covers a period from 724 BCE to 1974 CE. Besides a later correction of the end date of the sampling site chronologies Kirnsulzbach (Germany) and Gustavsburg (Germany) this master chronology has since not been changed and still remains one of the most important bases for dendrochronological dating in western Germany. It stands out in so far as it provides comprehensive graphical findspot series for each individual sampled site and year to year growth values for eight regional sub-chronologies in addition to the combined Central European reference curve.
Particularly due to the fact of Hollstein’s chronology being publicly available, it has frequently been criticized for its insufficient data to bridge the Late Antiquity between 350 and 400 CE with only three sampling sites (tomb near Beerlegem, Belgium; tomb inside of Cologne Cathedral, Germany; subfossil trees near Broichweiden, Germany) and that these site chronologies cover those decades with inadequate correlation coefficients. With regard to recent statistical threshold values for crossdating, Hollstein’s Late Antiquity bridging needs to be reconsidered.
Therefore, in a combined effort, the dendrochronological laboratories at Rheinisches Landesmuseum Trier (RLM), the University of Cologne and Albert-Ludwigs-University Freiburg re-evaluated Hollstein’s findings for
Late Antiquity by including the respective dendrochronological examinations conducted in Rhineland-Palatinate, North Rhine-Westphalia and north-eastern France during the past 40 years. A total of 62 site chronologies were compiled to establish a new Late Antiquity chronology. Thirteen of these site chronologies could be used to support Hollstein’s original bridging series between 350 and 400 CE while the mean series for Broichweiden had to be corrected from end date 365 to 503 CE. Furthermore, this new bridging chronology could be validated by comparing it to an independent chronology from southern Germany. This study thus proves that the integrity of Hollstein’s Central European Oak Chronology is not compromised by a flawed Late Antiquity bridging and that therefore dating based on the Roman part of this chronology can still be considered as absolute.