Search Results (11)

Archeological structures connected with iron metallurgy were identified in the outskirts of the town Lučenec, Slovakia. Based on the shapes and decoration of the ceramic fragments, it was possible to date them to the 9th or 10th century. The first group of discovered metallurgical materials included slags with low wüstite content, which looks like slag from younger higher-shaft furnaces. The second group included slags which could be attributed to the technology common at the time of the site’s existence: iron smelting in lower free-standing shaft furnaces with average efficiency. The third group were slags from the forging of iron blooms to remove pores and slag particles. The fourth group consisted of ceramics fragments (tuyeres and refractory material). Bog ore was probably smelted using principally oak wood charcoal. Full article

Due to compatibility issues between traditional reinforcing materials and the substrate of museum wooden artifacts, interface failure occurs after crack reinforcement, particularly under dry and wet cycling conditions. This significantly compromises the durability of reinforcement. To resolve this issue, dealkalized lignin was grafted onto epoxy acrylate (LEA) to synthesize a novel consolidant with both humidity responsiveness and mechanical compatibility. The resulting LEA exhibited excellent multilayer adsorption capability and demonstrated synchronous and uniform hygroscopic expansion behavior, closely matching that of archeological wood. DMA revealed that LEA2 has an elastic modulus of 261.58 MPa and a Poisson’s ratio of 0.35, comparable to artificially degraded wood, effectively mitigating interface stress caused by rigidity differences. Furthermore, LEA effictively reinforced micron-scale cracks while maintaining the original microstructure of the wooden artifact. This material provides a promising solution to the compatibility challenges of traditional consolidants under humidity fluctuations and offers a new approach for the stable preservation of museum wooden artifacts. Full article

The Gobi Wall is a 321 km-long structure made of earth, stone, and wood, located in the Gobi highland desert of Mongolia. It is the least understood section of the medieval wall system that extends from China into Mongolia. This study aims to determine its builders, purpose, and chronology. Additionally, we seek to better understand the ecological implications of constructing such an extensive system of walls, trenches, garrisons, and fortresses in the remote and harsh environment of the Gobi Desert. Our field expedition combined remote sensing, pedestrian surveys, and targeted excavations at key sites. The results indicate that the garrison walls and main long wall were primarily constructed using rammed earth, with wood and stone reinforcements. Excavations of garrisons uncovered evidence of long-term occupation, including artifacts spanning from 2nd c. BCE to 19th c. CE. According to our findings, the main construction and usage phase of the wall and its associated structures occurred throughout the Xi Xia dynasty (1038–1227 CE), a period characterized by advanced frontier defense systems and significant geopolitical shifts. This study challenges the perception of such structures as being purely defensive, revealing the Gobi Wall’s multifunctional role as an imperial tool for demarcating boundaries, managing populations and resources, and consolidating territorial control. Furthermore, our spatial and ecological analysis demonstrates that the distribution of local resources, such as water and wood, was critical in determining the route of the wall and the placement of associated garrisons and forts. Other geographic factors, including the location of mountain passes and the spread of sand dunes, were strategically utilized to enhance the effectiveness of the wall system. The results of this study reshape our understanding of medieval Inner Asian imperial infrastructure and its lasting impact on geopolitical landscapes. By integrating historical and archeological evidence with geographical analysis of the locations of garrisons and fortifications, we underscore the Xi Xia kingdom’s strategic emphasis on regulating trade, securing transportation routes, and monitoring frontier movement. Full article

The Mazarrón 2 shipwreck was found in 1994 on the beach of Playa de la Isla (Mazarrón, Murcia, Spain). This finding is extremely important because the boat and its lead cargo were still in a reasonable conservation state and, therefore, provided new data on naval construction, commercial goods, navigation routes, and the relationships between the Phoenicians and the local population in the 7th–6th century BC. Currently, the shipwreck remains underwater, protected by a metallic coffer. In the last 2 years, a Preliminary Studies Project has been carried out, supported by national and regional public institutions. This research aims to know the shipwreck’s conservation state and to determine the extraction and conservation methods at the Museo Nacional de Arqueología Subacuática ARQVA (Cartagena, Spain), where the conservation and restoration treatment will be conducted. The sampling strategy and analytical study included not only wood and other materials from the shipwreck and its cargo but also the seawater and the seabed materials in the vicinity of the shipwreck. This paper presents the results of the geochemical study of the archeological site. The applied methodology included physico-chemical tests, X-ray diffraction, optical microscopy, FTIR spectroscopy, field-emission scanning electron microscopy coupled with X-ray microanalysis, and X-ray microscopy. The results indicated that, despite the wreck being buried at a shallow depth (less than 50 cm) in a marine environment with a water column of 2–2.5 m, influenced by complex coastal dynamics that favor an oxic environment, early diagenetic processes like the formation of pyrite framboids are particularly intense in the pores and internal channels of the wreck’s wood, where a different dysoxic–anoxic environment prevails. These processes have been the main mechanisms to have affected the wreck and are related to the biogeochemistry of sediments. The sediments have been confirmed to be closely related to the geological context of the Mazarrón region. The conducted study found no significant evidence of pollution due to the lead cargo. Full article

Two ancient wooden vessels, specifically a monoxyle (1st century BCE to 1st century CE) and shipwreck (15th to 17th century CE), were excavated in a well-preserved state east of the confluence of the old Mlava and the Danube rivers (Serbia). The vessels were found in the ground that used to be river sediment and were temporarily stored within the semi-underground exhibition space of Mammoth Park. As part of the pre-conservation investigations, the primary aim of the research presented was to characterize the culturable mycobiomes of two excavated wooden artifacts so that appropriate conservation procedures for alleviating post-excavation fungal infestation could be formulated. Utilizing culture-based methods, a total of 32 fungi from 15 genera were identified, mainly Ascomycota and to a lesser extent Mucoromycota sensu stricto. Soft-rot Ascomycota of genus Penicillium, followed by Aspergillus and Cephalotrichum species, were the most diverse of the isolated fungi. Out of a total of 38 isolates, screened on 7 biodegradation plate assays, 32 (84.21%) demonstrated at least one degradative property. Penicillium solitum had the highest deterioration potential, with a positive reaction in 5 separate plate assays. The obtained results further broaden the limited knowledge on the peculiarities of post-excavation soft-rot decay of archaeological wood and indicate the biochemical mechanisms at the root of post-excavation fungal deterioration. Full article

Due to several of their characteristics, such as their renewability, sustainability, and eco-friendliness, nanocellulose-based materials are arousing growing interest from researchers in various fields of study and applications. The purpose of this review article is to provide an overall view of the most recent applications of these innovative bio-nanomaterials in the field of cultural heritage. First, an introduction of the different classes of cellulose nanomaterials and their synthesis and characterization methods is presented. After that, many consolidation treatments based on nanocellulose structures for the recovery of degraded and archeological wood, the stabilization of damaged painting canvases, and the deacidification of historical papers are shown in order to underline the advanced potential of nanocellulose for the conservation of artistic heritage and the respect for the environment. Full article

Some organosilicon compounds, including alkoxysilanes and siloxanes, proved effective in stabilizing the dimensions of waterlogged archaeological wood during drying, which is essential in the conservation process of ancient artifacts. However, it was difficult to determine a strong correlation between the wood stabilizing effect and the properties of organosilicon compounds, such as molecular weight and size, weight percent gain, and the presence of other potentially reactive groups. Therefore, to better understand the mechanism behind the stabilization effectiveness, the reactivity of organosilicons with wood polymers was studied using a 2D ¹H–¹³C solution-state NMR technique. The results showed an extensive modification of lignin through its demethoxylation and decarbonylation and also the absence of the native cellulose anomeric peak in siloxane-treated wood. The most substantial reactivity between wood polymers and organosilicon was observed with the (3-mercaptopropyl)trimethoxysilane treatment, showing complete removal of lignin side chains, the lowest syringyl/guaiacyl ratio, depolymerization of cellulose and xylan, and reactivity with the C6 primary hydroxyls in cellulose. This may explain the outstanding stabilizing effectiveness of this silane and supports the conclusion that extensive chemical interactions are essential in this process. It also indicates the vital role of a mercapto group in wood stabilization by organosilicons. This 2D NMR technique sheds new light on the chemical mechanisms involved in organosilicon consolidation of wood and reveals what chemical characteristics are essential in developing future conservation treatments. Full article

The control of air quality in museums or storages is of fundamental interest for the conservation of historic artifacts. The present work reports an example of application of RFID sensors developed in the European project SensMat and dedicated to this issue. The sensors are based on the variation of property of an RFID tag coupled with a sensitive silver thin film exposed to the environment. As it will be described in the paper, such low-cost sensors are interrogated by a commercial reader and provide the environmental corrosivity index and thus the presence of pollutants. The selected case study concerns the monitoring of pollution by H₂S in a building dedicated to conservation and restoration of archeological and historical woods. The ability of sensors to map spatially the corrosivity within buildings is highlighted. Full article

Low-intensity drying is widely believed to protect waterlogged archeological wood against the adverse effects of dimensional alteration and cracking. However, slow drying generates substantial costs for the conservation process. This study compares the effects on conservation of highly-degraded sapwood (SW) and slightly-degraded heartwood (HW) from waterlogged archeological Scots pine wood treated with polyethylene glycol either as a mixture of polyethylene glycol (PEG) 400/4000 or PEG 2000 solution and air-dried using different approaches. The reference air-drying approach, using gradually decreasing air relative humidity (RH), i.e., 96, 86, 75, 66, and finally 44% (multi-stage schedule), was compared to an alternative approach, using constant RH of 44% (single-stage schedule). The Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the decomposition of hydrophilic chemical wood components and revealed differences in the degree of degradation of waterlogged SW and HW. The drying time of PEG-treated waterlogged wood air-dried using a one-stage schedule was shorter compared to the drying time using multi-stage drying. Multivariate analysis (ANOVA) revealed that the drying schedule used after impregnation of waterlogged wood with PEG can have a beneficial effect on wood hygroscopicity and dimensional stability. The drying schedule significantly affected the equilibrium moisture content (EMC) of SW and HW and reduced tangential (S_T) shrinkage of SW. These results show the positive effect of the single-stage alternative drying approach on the dimensional stability of highly-degraded Scots pine SW impregnated with PEG 2000. In the case of slightly-degraded HW, the drying approach did not affect wood preservation. These results can be useful for the conservation of highly-degraded waterlogged Scots pine wood. Full article

Anthropogenic carbonates are pyrotechnological products composed of calcium carbonate, and include wood ash, lime plaster/mortar, and hydraulic mortar. These synthetic materials are among the first produced by humans, and greatly influenced their biological and cultural evolution. Therefore, they are an important component of the archeological record that can provide invaluable information about past lifeways. One major aspect that has been long investigated is the possibility of obtaining accurate radiocarbon dates from the pyrogenic calcium carbonate that makes up most of these materials. This is based on the fact that anthropogenic carbonates incorporate atmospheric carbon dioxide upon the carbonation of hydrated lime, and thus bear the radiocarbon signature of the atmosphere at a given point in time. Since plaster, mortar, and ash are highly heterogeneous materials comprising several carbon contaminants, and considering that calcium carbonate is prone to dissolution and recrystallization, accurate dating depends on the effectiveness of protocols aimed at removing contaminants and on the ability to correctly identify a mineral fraction that survived unaltered through time. This article reviews the formation and dissolution processes of pyrogenic calcium carbonate, and mineralogical approaches to the definition of a ‘dateable fraction’ based on its structural properties. Full article

New technologies are in development regarding the preservation of waterlogged archaeological wood items contaminated with Fe/S species. To this purpose, a bio-based treatment to extract these harmful species before further damages occur is presented. Thiobacillus denitrificans and desferoxamine were employed based on their specific properties to solubilize iron sulfides and uptake iron. The biological treatment was compared with oxidizing and complexing agents (sodium persulfate and ethylene diamine tetraacetate) traditionally used in conservation-restoration. Mock-ups of fresh balsa as well as fresh and archeological oak and pinewood were prepared to simulate degraded waterlogged wood by immersion in corrosive Fe/S solutions. The efficiency of both biological and chemical extraction methods was evaluated through ATR-FTIR and Raman spectroscopies and validated by statistical approach. Results showed that treatments did not affect the wood composition, meaning that no wood degradation was induced. However, the chemical method tended to bleach the samples and after treatment, reduced sulfur species were still identified by Raman analyses. Finally, statistical approaches allowed validating ATR-FTIR results. Full article