Miocene wood from the LaTrobe Valley coal measures,Victoria, Australia

An initial study of a collection of fossil conifer wood is reported from the late early Miocene Yallourn Clays, an interseam unit intergrading into the base of the early to middle Miocene Yallourn seam of the LaTrobe Valley, Victoria in southeastern Australia. The fossil wood shares characteristics with the modem genera Dacrycarpus and Dacrydium. On the basis of contiguous, uniseriate tracheid pitting and 1–2 podocarpoid cross field pits, it is placed in the form genus Podocarpoxylon, and the new species P. latrobensis. The wood is compared with extant Podocarpaceae and other Australian fossil woods. Its ring anatomy is consistent with low temperature or rainfall seasonality in the early Miocene.     

Study of interactions between polyethylene glycol and archaeological wood components by C high-resolution solid-state CP-MAS NMR

While use of polyethylene glycols, PEG, polymers for archaeological wood conservation has been well established, there is almost no study of such composite materials with carbon thirteen high-resolution solid-sate NMR. We demonstrate that NMR is an useful analytical tool to characterize rapidly samples of conserved wooden objects. By choosing an appropriate value of the contact time (from 3 to 5 ms) for which the PEG component gives only a small residual NMR signal in the CP-MAS experiment, it is possible to edit selectively the spectra of the wood components. It allows one to visualize the degradation extent of the archaeological wood even when the conservation processes have been already applied. Moreover, by studying the kinetics of CP-MAS experiments, the time constants, T_1ρH and T_CH values for PEG moiety were computed. From these data, it is shown that either in the crude commercial product or in incorporated in archaeological woods, two components are present and they are the signatures of crystalline (or ordered) and amorphous (or disordered) molecular domains. Moreover, it was shown in the archaeological woods that almost 30% of PEG was in close molecular interactions with lignins. This study is the first evidence that the PEG in conserved wood can interact at a molecular level with wood components. It also demonstrates that the PEG diffuses inside the residual cell walls of archaeological wood. This data are important for scientists in charge of process development for the conservation of wooden artifacts.     

The use of forest resources in central Iberia during the Late Iron Age. Insights from the wood charcoal analysis of Pintia,a Vaccaean oppidum

Charred woods may be used to effectively reconstruct past wood acquisition strategies. We used anthracological data from the pre-Roman settlement of Pintia (Padilla de Duero, Valladolid) to examine the use of forest resources at the local scale. Palaeoecological data revealed heterogeneous landscapes in the inland northern meseta with environments that offered diverse sources of wood for the inhabitants of Pintia, one of the first cities of inland Iberia. Pines (Pinus pinea/pinaster and Pinus sylvestris/nigra) and both evergreen and deciduous Quercus L. and Juniperus L. were the main taxa identified as both fuelwood and construction elements, but the assemblages and frequencies of these taxa differed depending on their use. We also examined the potential of models from human ecology by considering the frequency, handling time and the relative technological value of each taxon to model how people gathered wood resources. The results suggest that although local availability affected the forest resources that were used by the Vaccaei people, specific taxa were positively selected for specific uses.     

The impact of traditional land use on woodlands: a case study in the Spanish Central System

We analyse the consequences of traditional use on forest characteristics during the last millennium in a mountain area of Spanish Central System, using information contained in documents, as well as cartography and toponymy. In the Middle Ages the local forests were transformed into municipal dehesas (communal fenced woods), communal wood pastures and arable lands. Pinewoods located in areas above 1500 m decreased because of the high grazing pressure. In the fifteenth century two manors were created (Buitrago and Montesclaros). Livestock became an important factor during this period. As a consequence an open wood was formed and oak coppices were also abundant (the felling of this species was at that time permitted by the Ordinances). At the end of the period of traditional management, pinewoods were disappearing and the main forest areas were located only in municipal dehesas. The area of beech was reduced in favour of melojo oak and scrub, due to the lower sprouting capacity of the beeches and their lower drought tolerance. Open wood pastures remain only in the eastern part of the study area, where there has been less intense human intervention. After the abolition of manors in the nineteenth century, arable land increased in the western part of the area, which had a higher population density. In the twentieth century, both human and livestock pressure decreased substantially and pine species were reintroduced by reforestation. The primitive savannah was transformed into ‘infilled savannah’, while temperate species spread around their refuges in municipal woods.     

Wood deterioration in Chacoan great houses of the southwestern United States

Abstract

‘Great houses’ built by the Ancestral Puebloans (Anasazi) (900–1200AD) still contain thousands of pieces of wood used as beams, secondary roof supports and lintels. The wood is an integral part of the surviving Chacoan architecture and has served as a valuable resource for determining the exact age of the structures and for obtaining information about raw material production, procurement and harvesting methods. An assessment of wood deterioration at the great houses in Aztec Ruins National Monument and Pueblo Bonito, Pueblo del Arroyo and Chetro Ked located in Chaco Culture National Historic Park in New Mexico have revealed that both microbial and non-biological deterioration was taking place. The major type of decay found throughout the structures was caused by soft-rot fungi. Cavity formation in secondary walls of conifer woods and an erosion of cell walls in aspen woods was prevalent. A brown-rot type of wood degradation was also found, primarily associated with areas of subterranean termite damage. Another form of deterioration present in some of the woods was a chemical de fibration of wood. This corrosive attack, caused by high concentrations of salts, destroyed the middle lamella between cells, resulting in a stringy mass of loosely attached fibres. Reburial of great house structures as an effective conservation strategy will require an environment that is not conducive to decay, since active wood-destroying fungi are present in the prehistoric woods. If moisture and other conditions suitable for decay exist, the wood will be destroyed and this important historical resource lost.     

考古木材降解评价的物理指标

为寻找一种能较为科学、方便地反映木材降解程度的指标,共收集不同地方出土的13种木材,8个树种,对这些树种的考古木材与新鲜木材的含水率、干缩性、基本密度、气干密度、综纤维素等指标进行对比分析。实验表明,基本密度和最大含水率(饱水含水率)基本上能够反映古木的降解程度,可以作为反映古木降解程度的物理评价指标。     

Differentiating Aspen and Cottonwood in Prehistoric Wood from Chacoan Great House Ruins

Accurate taxonomic identification is an essential part of archaeological wood analysis. However, making identifications more precise than the genus level is usually not possible since species within the same genus typically possess very similar cellular morphology. This paper describes a method for distinguishing aspen (Populus tremuloides) from cottonwood (Populus fremontii, Populus angustifolia, Populus acuminata) in samples of wood collected from the San Juan Basin in northwestern New Mexico and southwestern Colorado. This method is then applied to archaeological wood samples from the Anasazi great house at Aztec Ruins National Monument in Aztec, New Mexico. The results of this study demonstrate that quantifiable differences do exist between aspen and cottonwood species and that the technique can be used to separate archaeological specimens of Populus wood.     

Timber economy in the Roman Age: charcoal data from the key site of Herculaneum (Naples,Italy)

The city of Herculaneum (Naples, southern Italy), buried by the volcanic eruption of Mount Somma-Vesuvius in 79 ad, is a key site for understanding the timber economy during the Roman period. In this paper, the results of charcoal analysis of different building element types are presented. Beams, joists, poles, planks and door and window frames were investigated allowing us a view of which timber the Romans preferred for building in this area. We also fit the taxonomic results into the reconstruction of the ancient Campanian landscape, and finally, we discuss the knowledge that the Romans had about the technological properties of the wood that they used for building and the possible selection criteria that they followed in choosing them. Coniferous timber is the preferred material for building purposes. Abies alba is especially used, this fact confirming its stronger presence in southern Italian woods during the past and suggesting that its decline is mainly due to human overexploitation. The large presence of Cupressus sempervirens, selectively used for the production of poles, confirms that this tree was cultivated in plantations for timber production in the Vesuvius area. Furthermore, it might indicate that cypress could have been present as a natural tree in the local vegetation, suggesting a forest type that nowadays almost completely disappeared from this area and from the entire Italy. The findings of Juglans regia, Pinus pinea and Olea europaea, typical elements of the Mediterranean cultural landscape, show that their use was not limited to fruit production and that Romans also appreciated their timber. Beside these local resources, the presence of Picea abies and Picea/Larix indicates the importation of timber from northerly regions, probably the northern Apennines and the Alps.     

Cainozoic euphorbiacean wood from the Canning Basin,Western Australia

A new species of fossil wood is described, Bridelioxylon canningense Bamford & McLoughlin, belonging to the Phyllanthoideae group of the Euphorbiaceae. The woods occur in indurated sandstones and conglomerates preserved in palaeochannels incised into the Upper Permian Condren Sandstone in the Landrigan Cliffs, northern Canning Basin, Western Australia. Based on the presence of the dicotyledonous woods and the geomorphological setting of the palaeochannel, a Palaeogene age is suggested for the host rocks. This is the first record of fossil euphorbiacean wood in Australia; pollen has been previously recorded. The fossil wood is most closely comparable to extant members of Bridelia that currently occupy the warmer and wetter parts of Australia.     

Sulfur and iron analyses of marine archaeological wood in shipwrecks from the Baltic Sea and Scandinavian waters

Analyses of marine archaeological wood from shipwrecks in the Baltic Sea area, Kronan, Riksnyckeln, Tattran, the Puck Bay Boat and the Ghost wreck, and at the Scandinavian West coast, the Göta wreck, Stora Sofia and the Viking shipwrecks of Skuldelev, show accumulation of sulfur compounds. The penetration profiles of sulfur and iron into the wood and the speciation of characteristic sulfur groups were evaluated by combining X-ray spectroscopic analyses, in particular S K-edge XANES (X-ray absorption near edge structure) and X-ray fluorescence, with ESCA and elemental analyses. The combined analyses support the hypothesis that hydrogen sulfide produced by sulfate-reducing bacteria reacts and accumulates at low iron concentration mainly as organically bound sulfur, which as in previous studies was found by X-ray spectro-microscopy to accumulate in lignin-rich parts of the wood cell walls. The presence of iron(II) ions from corroding iron promotes formation of pyrite and other iron(II) sulfides, which easily oxidise in aerobic conditions with high humidity. No significant differences in sulfur and iron accumulation were found in wood from shipwrecks in the east coast brackish water and the west coast seawater. Sediments from three wreck sites, the Göta wreck, Stora Sofia and Kronan, were analyzed to a depth of a few decimeters and showed especially at the Stora Sofia high sulfur concentrations, exceeding 3 mass%. S K-edge XANES analyses of the sediments showed mainly reduced forms of sulfur, in particular pyrite and iron(II) sulfides together with elemental sulfur.     

Making connections: a fresh analysis of an early neolithic pit and its contents

Outlined here is a new and detailed assessment of two Early Neolithic pits discovered in 1933 by Dr. E.C. Curwen on New Barn Down, Worthing. Newly obtained radiocarbon dates that place the pits between 4000–3800 BC make them amongst the earliest Neolithic features in Sussex and southern England. It is proposed that the pits (collectively known as Pit X) display connections not only to the nearby flint mines, but also to the immediate coastal zone and to wider England. The examination illuminates the practices of an Early Neolithic community, who were not only extracting flint from the nearby mines, but also familiar with new forms of material culture and social customs.     

The prehistoric pile-dwelling settlement of Stagno (Leghorn,Italy): wood and food resource exploitation

A pile-dwelling settlement, dated to the final Bronze–early Iron Age (XII–XI century BC), was excavated at Stagno, near Leghorn (Tuscany, Italy). The site presented a well-preserved portion of the wooden foundation structure buried by sediments rich in plant remains: both wood and plant remains were subjected to archaeobotanical investigation. The ultimate goal was to improve our knowledge on agricultural economy and wood usage in Tuscany during the prehistoric ages. The results pointed to a farming system based on Triticum spp. (wheat), Hordeum spp. (barley) and Leguminosae cultivation in addition to the gathering of wild fruits, such as Corylus avellana, Cornus mas, Prunus spp., Vitis spp. Many of these plant remains are associated to a wetland context. Mesohygrophilous trees, such as deciduous Quercus, Ulmus minor, Fraxinus cf. excelsior, and Sorbus were used for the construction of the pile-dwelling structures; the choice of these plants indicates a good knowledge of the technological characteristics of timber.     

Canine Digging Behavior and Archaeological Implications

Abstract

Pit features, frequently reported at archaeological sites, are usually thought be culturally produced. The numbers and forms of pits found at an archaeological site influence inferences of human activity; therefore, the inferred cultural origin of pits at archaeological sites needs to be demonstrated, rather than assumed. Ethnoarchaeological study of dog digging behavior, combined with our understanding of the long symbiotic relationship between human beings and canines, suggests that canine disturbance may be a significant factor in site formation processes. Canines are the probable agent for certain commonly reported pit forms, and are probably implicated in the disturbance of human-dug pits much more often than commonly understood. Dogs dig under a variety of conditions, including those expected in hunter-gatherer, pastoral, and agricultural sites. Excavation of recent dog-holes reveals marked similarities with certain features reported in the archaeological literature.     

Trees and shrubs: the use of wood in prehispanic Teotihuacan

Charcoal recovered from different archaeological excavations carried out in the Teotihuacan Valley, México was used to evaluate whether significant changes in the use of wood took place through time (approx. 400 B.C.–A.D. 1500). Sixteen taxa of trees and shrubs characteristic of the Basin of Mexico were identified (including Pinus, Quercus, Arbutus, Cupressaceae, Alnus, Prunus, Taxodium, Salix, Baccharis and Buddleia, among others). Variations in the proportions of taxa are interpreted as a reflection of the intensity of use rather than an indicator of deforestation. The analysis of the data shows a pattern of continuity in the utilization of taxa throughout the occupation. This includes the use of different vegetative parts (trunk and branches), genera and species with different life forms (trees, shrubs, herbaceous plants) and primary (Pinus and Quercus) as well as secondary taxa (Prunus and Arbutus). We propose that the inhabitants of the Teotihuacan Valley implemented practices to manage vegetation in order to assure resource availability in the region.     

First record of fossil woods from the Mariño Formation (Miocene), Mendoza,Argentina and their palaeobiogeographical implications

The first Miocene records of silicified fossil woods from the Mariño Formation, Potrerillos area, Andes Precordillera, Mendoza province, Argentina are described. Rhaphithamnoxylon artabeae gen. et sp. nov. is described as the first fossil wood referable to Verbenaceae from Argentina. This new fossil species is related to extant Rhaphithamnus Miers, sharing the following anatomical features: diffuse porosity, distinct growth ring boundaries, numerous small to very small vessels, commonly in radial multiples, 1–3 seriate rays, and heterocellular and scarce paratracheal axial parenchyma. Rhaphithamnus contains only two extant species: R. spinosus (A.L. Juss.) Moldenke, which occurs in the Valdivian forests of Chile and Argentina, and R. venustus (Philippi) Robinson, which is endemic to the Juan Fernández Islands. Representatives of Verbenaceae are distributed predominantly in the Americas from Patagonia (Argentina) to Canada, and they are inferred to have originated in South America. The fossil wood described herein provides new age and geographical constraints on the raphithanoid lineage within Verbenaceae. Other fossil woods recorded from the Mariño level are retained under open nomenclature, as they possess a combination of mostly solitary broad vessels, and smaller vessels in radial multiples or in clusters, with numerous, vasicentric to confluent axial parenchyma, and heterocellular, high rays. Thus, they have features akin to dicotyledonous lianas or vine-like or small shrub species.     

A pollen analytical record for hemp retting from Dungeness Foreland,UK

This paper presents late Holocene pollen analytical, plant macrofossil and radiocarbon data from a sequence filling a natural pit developed in the gravel beaches of Dungeness Foreland, southeast England. Pollen analysis of organic muds from the base of Muddymore Pit contain exceptionally high pollen frequencies for Cannabis sativa L. and indicate the past use of the site as a hemp-retting pit. The timing of the pollen record for Cannabis (ca. AD 1000–1400) corresponds with a period during which the nearby town of Lydd reached the height of its prosperity and importance as one of the lesser havens of the ‘Cinque Ports’ confederation. It is proposed that the hemp-retting site at Muddymore Pit went a long way towards satisfying demand from the port for the products of hempen fibre such as rope (for ships rigging) and cloth (for ships sails).     

How natural are natural woods from wetland sites? – a case study at two sites of the Jomon period in central Japan

To clarify the characteristics of natural woods from wetland sites, the taxonomic composition and diameter of natural woods were compared with those of wooden artifacts at two sites of the middle to latest Jomon periods (ca. 5300–2800 cal BP) in central Japan that have contrasting characters. The Oise-yama site in Saitama was a least used site only with a few pit dwellings and pits on the surrounding upland and no structures in the wetland. The Shimo-yakebe site in Tokyo was a heavily used site with wooden structures and rows of stakes in the wetland and many remains on the upland. Natural woods of the Oise-yama site had an exponential decrease along the diameter gradient, irrespective of taxa, but wooden artifacts of the Shimo-yakebe site had clear marks of human selection both in the taxonomic composition and diameter. Natural woods of the Shimo-yakebe site also had an exponential decrease along the diameter gradient similar to those of the Oise-yama site. Thus, the exponential decrease in the diameter distribution seemed to be intrinsic in naturally deposited, allochthonous woods found at wetland sites.     

Miliacin in palaeosols from an Early Iron Age in Ukraine reveal in situ cultivation of broomcorn millet

During the archaeobotanical investigation of Scythian–Sarmatian period (Early Iron Age), pits with crop processing waste, discovered in the floodplain of Donets River, eastern Ukraine, and charred remains of cereal grains, dominated by broomcorn millet, were recorded. The grains from the pits were radiocarbon dated to the fifth to first century BC. Those pits are distant from any known contemporaneous settlement. The apparent disconnection of these pits from any local settlement suggests that (1) millet was brought from other locations by mobile groups, or (2) millet was cultivated locally by populations whose settlements have left no discernible archaeological trace. The analysis of molecular biomarkers preserved in palaeosols that are stratigraphically connected to the pits revealed high levels of miliacin, a molecule that can be preserved in ancient soils and sediments, and that is consistent with broomcorn millet (Panicum miliaceum). High levels in miliacin in soils stratigraphically connected to the pits are interpreted as the result of a large biomass of P. miliaceum produced at time of soil formation. Our biogeochemical results applied to a palaeosol thus attest to the in situ cultivation of crops dominated by the broomcorn millet during the early Iron Age in the floodplain of Donets River. Biochemical examination of soils and palaeosols can thus provide useful information on past dynamics of land-use by ancient population, especially when settlements or macrobotanical remains are absent.     

Seasoned or green? Radial cracks analysis as a method for identifying the use of green wood as fuel in archaeological charcoal

For several years, sociological questions have been central in anthracology. The development of socio-economic approaches based on the recognition of anatomical signatures in wood has made it possible to focus on topics related to firewood use and its management. The presence of radial cracks (RC) on archaeological charcoal is generally interpreted as the result of the burning of green wood. The present study proposes a verification of this theory by the experimental combustion of seasoned and green wood of Scots Pine (Pinus sylvestris L.). Experimenting with this species was a research priority since it was the dominant taxon (representing 80-100% of the charcoal remains) identified in the Palaeolithic European sites under consideration.The experiments were conducted using two different methods: (i) inside a muffle furnace that allowed us to control the combustions, but in which the combustion process is quite different from most archaeological situations and (ii) in an open fireplace, less controllable but closer to the archaeological conditions. The systematic quantification of the number, length and width of the radial cracks (RC) measured on the transversal sections of the experimental samples demonstrates that (i) radial cracks occur independently of the moisture content of the wood before the combustion (on green and seasoned wood); (ii) however, the average number of radial cracks (RC/cm²) allows distinguishing seasoned from green wood; (iii) in the muffle furnace, the size of the RC appeared to be a good criterion for discriminating seasoned and green wood, but this observation was not confirmed by the open-air combustions. Our results clearly show that the appearance of radial cracks is not diagnostic of the combustion of green wood. Nevertheless, the number of radial cracks (RC/cm²) could represent a new method that might help identifying the combustion of green wood in archaeological charcoal samples.     

Rhexoxylon cortaderitaense (Menéndez) comb. nov., a species of permineralized stems newly assigned to the Corystospermaceae,from the Triassic of Argentina

Bodnar, J., June, 2008. Rhexoxylon cortaderitaense (Menéndez) comb. nov., a species of permineralized stems newly assigned to the Corystospermaceae, from the Triassic of Argentina. Alcheringa 32, 171–190. ISSN 0311-5518.

Anatomically preserved stems of Late Triassic corystosperms from the upper Cortaderita Formation in San Juan province, Argentina are described and assigned to Rhexoxylon cortaderitaense (Menéndez) comb. nov. These specimens were originally attributed to conifers, a group not closely related to corystosperms. The silicified axes preserve features of the cortex, pith, and secondary vascular system. Like all Rhexoxylon species, these axes have two discontinuous cambial rings that develop centrifugal secondary xylem (normal secondary xylem) and centripetal secondary xylem (inverted secondary xylem). Both types of xylem are separated by a band of parenchymatous tissue developed by a remnant cambium. The centrifugal xylem is divided by parenchymatous rays following differential cambial activity. The secondary xylem is pycnoxylic with uniseriate rays; tracheids have mainly biseriate and alternate bordered pits on radial and tangential walls, and one simple oval pit in cross-fields. The distinctive feature of R. cortaderitaense is the conspicuous amount of centripetal secondary vascular tissues not forming perimedullar bundles, this being interpreted as an apomorphic trait. This interpretation of the character modifies previous hypothesized phylogenetic relationships of corystosperm wood taxa.