Dendrochronological Dating of Wooden Artefacts using Photography

Core sampling is normally used for dendrochronological age determination of both timber and living trees. As core sampling can seriously damage artefacts, a photographic method was tried on 29 wooden objects made of Scots pine (Pinus sylvestris L.). These were photographed and tree‐ring sequences for dendrochronological analysis were measured on the photographs in the laboratory. Nine objects could be dated. The undatable objects had few tree‐rings or a non‐matching tree‐ring pattern. The region in Norway where the material had grown could be determined by matching against various regional chronologies.     

Dendrochronological dating of a wooden causeway in Finland

A mean ring‐width chronology for Scots pine in eastern Finland has been compiled based on living trees and dendrochronologically dated historical timber constructions. As an application of this master chronology, a young archaeological site near the town of Hämeenlinna, southern Finland, was dated. A previous assumption of the age of this site was that it could even be medieval. The construction was not older than 160 years, the road having been built after 1828, the year of growth of the outermost tree rings of the samples. A new pine chronology for southern Finland extending to the year AD 1539 is presented and it is now applicable for precise dating purposes in this area.     

A simple Bayesian approach to tree‐ring dating

Tree‐ring dating involves matching sequences of ring widths from undated timbers to dated sequences known as ‘master’ chronologies. Conventionally, the undated timbers (from a building or woodland) are sequentially matched against one another, using t‐tests to identify the relative offsets with the ‘best’ match, thus producing a ’site’ chronology. A date estimate is obtained when this is matched to a local master chronology of known calendar age. Many tree‐ring sequences in the UK produce rather low t‐values and are thus declared not to have a ‘best’ match to a master chronology. Motivated by this and the routine use of Bayesian statistical methods to provide a probabilistic approach to radiocarbon dating, this paper investigates the practicality of Bayesian dendrochronology. We explore a previously published model for the relationship between ring widths and the underlying climatic signal, implementing it within the Bayesian framework via a simulation‐based approach. Probabilities for a match at each offset are produced, removing the need to identify a single ‘best’ match. The Bayesian model proves successful at matching in both simulated and real examples.     

Can tree-ring chemistry reveal absolute dates for past volcanic eruptions?

Discussion of the significance of volcanically induced impacts on human history, the natural environment, and climate through the Holocene, has frequently stalled because of controversy concerning certain key volcanic eruptions and their precise relationships with the archaeological/environmental record. A major stumbling block in such debates is a failure to obtain precise and accurate dates for many of these key volcanic events. Most existing dates currently float against archaeological, historical, environmental, and climate data. A potential means to resolution lies with tree rings: these can be dated precisely by dendrochronology, are available from a wide range of loci around the world, and can record global climatic influences. It has been suggested that certain growth anomalies in dendrochronological sequences could offer “proxy” absolutely dated records of major, climatically effective, volcanic eruptions. However, this assertion has been widely disputed given the lack of a direct, positive, causal connection. The hypothesis that the required connection may be chemically encoded in individual annual growth rings from dated sequences is explored here both via review of existing literature on dendrochemical techniques, and by LA-ICP-MS chemical analysis of two tree ring sequences. It is concluded that dendrochemistry provides a promising means by which absolute dates may one day be attributed to key volcanic eruptions of pre-modern times.     

Provenancing Baltic timber from art historical objects: success and limitations

During the Middle Ages northern Belgium and The Netherlands were gradually deforested. A steadily rising demand for quality timber obliged merchants to look for new timber sources. From the 13th century onwards, large volumes of timber were imported from surrounding regions and, despite the remote supply area, merchants of the Hanseatic League managed to organize a huge timber trade from towns around the Baltic Sea.Trees from forests along the Vistula River seem to have been exported via Gdansk, first to Bruges and later to Antwerp. At their final destination the imported wood assortments were highly appreciated for shipbuilding and construction purposes, but also by woodcarvers and famous painters.Over the last decade dendrochronologists have established a dense network of historical site chronologies for northern and central Poland. These site chronologies are supposed to reflect local growth conditions and may allow the identification of the provenance of the wood of many art historical objects made out of Baltic timber.Tree-ring patterns of panel paintings and sculptures, mainly from the 14th–16th centuries, were measured and compared to this data set of site chronologies. An evaluation of the accuracy of sourcing medieval Baltic timbers using standard correlation techniques was made. The identification of provenance enriches historical information on logging activity and timber trade around the Baltic Sea during the Middle Ages.     

Near-Infrared Aerial Crop Mark Archaeology: From its Historical Use to Current Digital Implementations

Even though most archaeologists are aware of the crop mark phenomenon and its possible archaeological nature, the information on its occurrence and specific character is, in most cases, obtained by imaging in the visible spectrum. After the Second World War, the occasional use of near-infrared (NIR) sensitive emulsions attributed this kind of invisible imaging with a great potential. However, archaeological NIR imaging always remained restricted due to several reasons not, at least, its complicated workflow and uncertain results. This article wants to delve deeper into the subject, looking at the conventional film-based approach of NIR aerial reconnaissance and its historical use in archaeological crop mark research, after which a current straightforward digital approach will be outlined. By explaining the spectral properties of plants and using examples of recently acquired NIR imagery in comparison with visible frames, it should become clear why the detection and interpretation of crop marks can benefit from low-cost digital NIR imaging in certain situations.     

Surfaces from the Visual Past: Recovering High<Emphasis Type="Bold">-</Emphasis>Resolution Terrain Data from Historic Aerial Imagery for Multitemporal Landscape Analysis

Historic aerial images are invaluable sources of aid to archaeological research. Often collected with large-format photogrammetric quality cameras, these images are potential archives of multidimensional data that can be used to recover information about historic landscapes that have been lost to modern development. However, a lack of camera information for many historic images coupled with physical degradation of their media has often made it difficult to compute geometrically rigorous 3D content from such imagery. While advances in photogrammetry and computer vision over the last two decades have made possible the extraction of accurate and detailed 3D topographical data from high-quality digital images emanating from uncalibrated or unknown cameras, the target source material for these algorithms is normally digital content and thus not negatively affected by the passage of time. In this paper, we present refinements to a computer vision-based workflow for the extraction of 3D data from historic aerial imagery, using readily available software, specific image preprocessing techniques and in-field measurement observations to mitigate some shortcomings of archival imagery and improve extraction of historical digital elevation models (hDEMs) for use in landscape archaeological research. We apply the developed method to a series of historic image sets and modern topographic data covering a period of over 70 years in western Sicily (Italy) and evaluate the outcome. The resulting series of hDEMs form a temporal data stack which is compared with modern high-resolution terrain data using a geomorphic change detection approach, providing a quantification of landscape change through time in extent and depth, and the impact of this change on archaeological resources.     

Oaks,tree-rings and wooden cultural heritage: a review of the main characteristics and applications of oak dendrochronology in Europe

We overview the recent development of oak dendrochronology in Europe related to archaeology and art-history. Tree-ring series of European oaks (Quercus robur and Q. petraea) have provided a reliable framework for chronometric dating and reconstruction of past climate and environment. To date, long oak chronologies cover almost the entire Holocene, up to 8480 BC and the network over the entire area in which the two oaks grow is being improved. We present the main characteristics of oak ring series and discuss the latest methodological advances in defining the calendar year in which the tree-rings were formed and in interpreting such dating in terms of the age of a wooden object. Dendrochronology has established itself as a standard dating tool and has been applied in a wide variety of (pre-)historical studies. Archaeological wood, historical buildings, works of art (such as panel paintings and sculptures) have been successfully investigated. Recent advances in dendro-provenancing have helped to obtain more information on the timber trade in the past. Information on past forest structures, silviculture and timber use have become available through scrutinizing historical and contemporary ring-width patterns.     

The Context and Significance of Copper Artifacts in Postclassic and Early Historic Lamanai,Belize

Abstract

We consider the archaeological contexts in which copper objects have been recovered at the ancient Maya site of Lamanai in northern Belize and the significance these objects had for the residents of the community during Postclassic (ca. A.D. 950–1544) and Spanish colonial (post 1544) times. More copper objects have been recovered from controlled archaeological contexts at Lamanai than any other site in the southern Maya lowlands area. Bells make up the majority of the assemblage during the centuries just prior to and during historical times, but high status objects such as rings and clothing ornaments found in elite burials dominate in the Early Postclassic period. All of these objects were imported from outside the Maya area. Utilitarian objects, including needles, axes, and fish books, are found in a variety of contexts during Late Postclassic and Spanish colonial times, as are bells and rings. Production materials, including prills, blanks, and pigs/ingots, in addition to mis-cast objects that are production failures, also appear during this time. Nearly all of the copper objects found at Lamanai are distinctly Mesoamerican in form and design, and based on metallurgical analyses it appears that manufacturing technologies were distinctly Mesoamerican as well. The presence of production materials and mis-cast piecesy along with the results of chemical compositional and microstructural analyses, support the idea that the Maya at Lamanai were engaged in the on-site production of copper objects by late precolumbian times.     

固相微萃取-气相色谱-质谱在《江友渚等七挖书画轴》挥发性有机化合物分析中的应用

文化遗产的气味不仅反映了文物的历史信息,还对文化遗产自身产生持续性的影响,因此了解文化遗产的气味对其价值研究和当代保护都具有重要意义。本工作采用固相微萃取-气相色谱-质谱技术对中国国家博物馆藏《江友渚等七挖书画轴》天头用纸散发的气体进行了采集、分离和分析。结果表明：与纸张降解相关的标志物(如脂肪酸、醛、酮等)得到有效采集;而其他生物标记物(如沉香螺醇)的检出也反映了该书画轴的历史保存环境信息。此方法对该件书画轴的历史价值认知和科学保护具有重要作用。     

First dendroarchaeological dates of prehistoric contexts in South America: chullpas in the Central Andes

Despite the existence of long-lived tree species with excellent tree-ring characteristics, the use of dendrochronological techniques for dating archaeological contexts has been very limited in South America. Recent research in the Bolivian Altiplano of the Central Andes has yielded a network of Polylepis tarapacana chronologies that goes back to the 13th century. This species was regularly used by local populations since pre-Columbian times as raw material for beams, lintels, hooks and other architectural features in houses, storage chambers, and sepulchers. The aim of this study is to argue in favor of the potential of P. tarapacana for providing high resolution dates of significant archaeological events during the pre-Columbian era. The chronology of chullpas (burial towers and storage chambers) in the southern Andean Altiplano is used as a case study. Growth rings from P. tarapacana have provided several centennial-length dendrochronological records including a reference regional chronology covering the last 786 years in the Central Andean highlands. Based on this long reference chronology calendar years were assigned to woody pieces from pre-Hispanic chullpas. Dendroarchaeological results are consistent with contextual evidence and most radiocarbon dates from woody samples and related archaeological items. Our results indicate that P. tarapacana has a high potential for providing annually-resolved tree-ring dates for archaeological contexts in the Altiplano since the early 13th century.     

Cave Art in Context: Methods for the Analysis of the Spatial Organization of Cave Sites

Investigations of prehistoric cave art have long neglected the surrounding context: space, archaeological objects, and imprints. As a result, an integrative structural approach that analyzes cave art as part of an anthropomorphized landscape has not been available. This article draws on urban planning and the physiology of the human eye to provide an innovative archaeospatial analysis of cave sites. A set of relevant features from the caves of Bédeilhac, Fontanet, and Le Portel was selected and defined (light zone, chamber type, path network, mode of movement, and available space). An analysis of the prehistoric remains in the caves allows the reconstruction of different concentrations of human activities (cave art, archaeological objects, and imprints). The projection of these concentrations onto the structured map of the caves results in four types of locations: drawing location, supply location, drawing location with substantial activities, and drawing location with consumption activities. This approach opens new avenues for the archaeological perception of caves and their inhabitants: Upper Paleolithic humans were very familiar with caves and probably followed a master plan during their stay in the dark.     

数字近景摄影测量在秦始皇陵百戏坑考古中的应用研究

既要保留遗迹在不同阶段的信息资料,又不影响发掘研究工作的继续进行,一直是考古工作者探索研究的问题。为配合秦始皇陵百戏俑坑的考古发掘工作,为后续考古研究和文物遗迹的保护提供必要的基础信息资料,针对大场景考古发掘现场,通过数字全站仪对文物挖掘现场布设的一定数量控制点进行观测获取其三维点位坐标。利用非量测数码相机获取现场多航带序列影像,通过数码相机检校、自动空中三角测量、影像特征提取与影像匹配、数字微分纠正等数字近景摄影测量方法,获取反映发掘现场文物分布情况的数字高程模型(DEM)和正射影像(DOM)数据。在生成的正射影像图上进行文物轮廓线条的提取,获得发掘现场文物的正射投影矢量图。实现文物位置、形状及分布的平面量测。实验证明:该方法不仅可大面积、快速获取文物挖掘现场文物分布的正射投影平面图,实现考古数字制图,而且能保证一定的精度。具有较高的推广应用价值。     

The Direct Historical Approach, Analogical Reasoning, and Theory in Americanist Archaeology

Prior to the early 1950s, Americanist archaeologists, given their interest in chronology, routinely searched for direct historical connections between ethnographically documented cultures and archaeological cultures. In those instances where clear evolutionary connections existed between ethnographic and prehistoric cultures, the ethnic affinities of the latter could be assessed, chronologies of prehistoric cultures could be built, and ethnographic descendant cultures could be used as analogs of prehistoric ancestral cultures. The latter became known as specific historical analogy, and it stands in contrast to general comparative analogy, in which no detectable evolutionary connection exists between archaeological subjects and ethnographic sources. The theory underpinning the use of specific historical analogs is Darwinian evolutionism, or descent with modification; thus similarities between ethnographic sources and archaeological subjects are homologous. By midcentury, with the problem of chronology behind them, archaeologists began to address anthropological concerns. Darwinian evolutionism was replaced by the theory of orthogenesis as an explanation of culture change, and concomitantly specific historical analogy was replaced by general comparative analogy, in which similarities between ethnographic sources and archaeological subjects are the result of convergence. For over a century anthropologists and archaeologists have mixed elements of the two theories.     

Radiocarbon dating and the “old wood” problem: The case of the Hohokam chronology

Many archaeological chronologies, including that of the Hohokam in southern Arizona, are based on a series of radiocarbon dates on wood. This paper argues that because of variability in rates of wood decay processes (in the environment and in systemic context), such archaeological chronologies are potentially biased towards excessive antiquity by an old wood problem and must be reassessed. Following the theoretical insights of Dean (1978), this paper sets forth principles and procedures for relating radiocarbon dates to cultural events. Emphasis is placed on identifying and taking into account the formation processes of (1) the dated specimens and (2) the deposits that yielded them. This methodological framework is applied to Hohokam radiocarbon dates, and a chronology much shorter than the original Gladwin-Haury formulation is supported.     

The Dendroecological Potential of Eucalyptus Camaldulensis Dehnhardt (River Red Gum) from the Barmah Forest,Victoria, Australia

The study of tree rings has been used for over 100 years to inform climatic and geomorphological reconstructions. In mainland Australia, no tree species are currently recognised as providing reliable sources for such studies over extensive areas. Eucalyptus camaldulensis is a widely growing species with a growth pattern that is closely linked to high levels of available moisture, such as that associated with floods. The species therefore has the potential to provide palaeoclimatic information that may be of use in hydrological and geomorphological studies. This study initially examines the microstructure of samples of E. camaldulensis taken from the Barmah Forest to assess the applicability of the species to dendroecological investigation. It is found that samples of the species exhibit ring‐like structures, although there are areas of the samples that contain zones of growth without clear ring boundaries. The patterns of growth rings and zones are found to be common to many trees at a site, although the level of variability of pattern from tree to tree is high. Options for future development of the approach described here are to combine ring studies with isotopic‐based analysis to provide a combination of tree age and climatic history.     

Mounds,Towns, and their Surrounds: An Archaeological,Historical, and Geophysical Approach to Burial Mounds,Residential Space,and Cultural Landscapes of the Late Woodland Springwells Site (a.d. 800–1400) at Historic Fort Wayne,Detroit

Historic Fort Wayne is located on the Detroit River in a landscape of heavy industry and marginalized urban neighborhoods (figure 1). Geophysical survey south of the Fort Wayne Mound—a Late Woodland Period burial mound enclosed by the Fort—indicates that pre-contact residential structures may be preserved at the site. Residential sites with mortuary monuments are uncommon in southeastern Michigan and represent an opportunity to better understand variation in Late Woodland settlement. Our approach combines existing archaeological research, historical records, and non-invasive geophysical survey in a culturally sensitive Native American site context presently unavailable for conventional archaeological excavation. We examine archaeological and historical records from Springwells and Late Woodland period settlements in the region to contextualize geophysical evidence from the site. The research prioritizes protection of Native American heritage sites in urban contexts together with ongoing archaeological interpretation of the Late Woodland cultural Landscape.     

Ankersmit's Postmodernist Historiography: The Hyperbole of "Opacity"

Ankersmit's articulation of a postmodern theory of history takes seriously both the strengths of traditional historicism and the right of historians to decide what makes sense for disciplinary practice. That makes him an exemplary interlocutor. Ankersmit proposes a theory of historical "representation" which radicalizes the narrative approach to historiography along the lines of poststructuralist textualism. Against this postmodernism but invoking some of his own arguments, I defend the traditional historicist position. I formulate criticisms of the theory of reference entailed in his notion of "narrative substance," of his master analogy of historiography with modern painting, and finally of his characterization of historical hermeneutics. In each case I find him guilty of the hyperbole which he himself cautions against. While it is true that historical narratives cannot be taken to be transparent, in taking them to be opaque Ankersmit puts himself in an untenable position. Finally, Ankersmit seeks to buttress his theoretical case by an interpretation of the new cultural historical texts of authors like Davis and Ginzburg. While this is a concreteness heartily to be welcomed in philosophers of history, I cannot find his construction of this new school's work plausible.     

Pencils and Pixels: Drawing and Digital Media in Archaeological Field Recording

Within the context of a growing emphasis on digital recording, what is the place of analog drawing in archaeological fieldwork? In this article, we situate the increased application of digital drawing methods by providing several historical examples of archaeological field drawing in British archaeology to demonstrate the connection between understanding the archaeological record and illustration. Given this background of analog archaeological recording, we then explore the current state of archaeological field drawing and the affordances of digital illustration for recording and interpreting the archaeological record, review literature in architecture and design regarding the cognitive function of analog and digital drawing, and discuss the possible future implications of born-digital or paperless archaeology.