The use of red pigments linked to burial practices is widely documented in the Iberian prehistoric record and very often it has been traditionally interpreted as a ritual practice entailing the utilisation of local raw materials (iron oxides). Some research works, nevertheless, have also detected the use of red pigments which can only be interpreted as allochthonous. The red pigments spread over a single inhumation in a monumental Megalithic tomb surrounding Valencina de la Concepción Copper Age settlement was studied by means of X-ray diffraction, field emission scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray microfluorescence, micro-Raman and Fourier transform infrared spectroscopies. This approach allowed characterising the red pigments as cinnabar, mixed with tiny amounts of iron oxides. The presence of cinnabar, a product that was necessarily imported, in a context of an exceptional set of grave goods, suggests that the use of cinnabar was linked not only to ritual but also to practices related to the display of social status.
Different Mediterranean Basin limestones, like Calcário Ançã (Portugal), Calcário Lioz (Portugal), Piedra San Cristobal (Spain), Piedra Escúzar (Spain) and Pietra di Lecce (Italy), have been widely used as building materials in the European architecture. The aim of this study was focused on biodeterioration, mainly on evaluation of the primary bioreceptivity of those materials. A set of samples was inoculated with a cultured photosynthetic biofilm under laboratory conditions. Several assessment tools were applied to monitor the colonization overtime of the different lithotypes. After 3 months of incubation the colonization occurred endolithically in some lithotypes, namely Piedra San Cristobal and Piedra Escúzar. Spectrophotometric determination of chlorophyll a was a useful analytical technique to achieve the total amount of photosynthetic biomass on rock substrates, demonstrating that Piedra Escúzar and Calcário Lioz were the highest and lowest bioreceptive lithotypes, respectively. Microscopic and image analyses were essential to understand the stone colonization process and its pattern of distribution. Physical stone parameters and exposure conditions were shown to play an important role in the establishment and development of photosynthetic colonization.
Rocks, either in natural geological outcrops or in stone monuments, are common habitats for a wide variety of microorganisms which colonize both rock surfaces and cracks. Physical properties such as porosity and surface roughness make limestone susceptible to biological colonization, which may induces aesthetic and/or physical and chemical damages. Organisms causing biodeterioration on monuments have usually been controlled by chemical products (biocides). In order to overcome the impact of these substances on the environment, human health and stone substrates, alternative tools such as natural products from plants or microorganisms can be used as an innovative approach for stone conservation. \ud
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In this work, the efficiency of natural biocides (cells free culture filtrates of Trichoderna harzianum and Burkholderia gladioli, as well as glycoalkaloids from spontaneous Solanaceae) was tested under laboratory conditions against a multi-species phototrophic culture developing on Hontoria limestone. Their efficiency was assessed by digital image analysis, in vitro chlorophyll a quantification and confocal laser scanning microscopy. These techniques showed a good correlation, revealing that cells free filtrate of Trichoderma harzianum had an antagonistic action against the multi-species phototrophic culture tested in this work
A laboratory-based methodology was designed to assess the bioreceptivity of glazed tiles. The experimental set-up consisted of multiple steps: manufacturing of pristine and artificially aged glazed tiles, enrichment of phototrophic microorganisms, inoculation of phototrophs on glazed tiles, incubation under optimal conditions and quantification of biomass. In addition, tile intrinsic properties were assessed to determine which material properties contributed to tile bioreceptivity. Biofilm growth and biomass were appraised by digital image analysis, colorimetry and chlorophyll a analysis. SEM, micro-Raman and micro-particle induced X-ray emission analyses were carried out to investigate the biodeteriorating potential of phototrophic microorganisms on the glazed tiles. This practical and multidisciplinary approach showed that the accelerated colonization conditions allowed different types of tile bioreceptivity to be distinguished and to be related to precise characteristics of the material. Aged tiles showed higher bioreceptivity than pristine tiles due to their higher capillarity and permeability. Moreover, biophysical deterioration caused by chasmoendolithic growth was observed on colonized tile surfaces.
a b s t r a c tRock art paintings, and in general mural paintings, are one of the many elements of cultural heritage complex systems. As the different elements of a system have diverse spatial positions, spatial recording allows understanding their interactions. Thus, a useful approach to mural paintings recording is to understand it as a microcartography issue, managing each element of the system as a cartographic coverage.The approach implemented emphasizes the utilization of data obtained by remote sensing techniques for extracting different kinds of information susceptible of being analysed, classified and plotted in a differentiate way by means of the possibility of reducing redundant data by Principal Component Analysis (PCA) and the elaboration of false-colour images from uncorrelated bands.A laboratory model was prepared in order to simulate biodeterioration of rock art. The samples were photographically recorded thereafter under different lighting conditions, and PCA applied to the resulting images. False-colour images obtained by combining Principal Component bands allowed us to reach results similar to those of an unsupervised classification. The method has been applied to Roman mural paintings from one of the tombs of Carmona Necropolis, obtaining good results.
Iberian ‘warrior’ stelae have captured the imagination of researchers and the public for more than a century. Traditionally, stelae were considered ‘de-contextualised’ monuments, and research typically focused on the study of their iconography, paying little or no attention to their immediate contexts. As a result, despite the large number of these stelae known to date (c. 140) and the ample body of literature that has dealt with them, fundamental questions remain unanswered. This paper aims to demonstrate the potential of a multidisciplinary and contextual approach to push forward the research agenda on these monuments through a case study. Firstly, we introduce the Mirasiviene stela and the methods deployed for its investigation, which include a variety of digital imaging techniques, petrography, pXRF, intensive survey and multiscalar spatial analysis. Secondly, we discuss the results in relation to three main topics: stela biography, social practices and landscape context. Comparisons to the well-known nearby Bronze Age and Iron Age site of Setefilla are made throughout the discussion. Ultimately, this paper makes a case for the stelae of Mirasiviene and Setefilla being polyvalent monuments made by local artisans, that served both as landmarks and memorials in connection with dense late second and early first millennium BCE settlement patterns in the region. Probably linked to elites, ‘houses’ or kin groups of this time, stelae were set in symbolically charged places, liminal spaces nearby water, burials and pathways, attracting a range of ritual activities throughout the centuries. The study of the newly discovered Mirasiviene stela shows that multidisciplinary, cutting-edge non-destructive archaeology can shed significant new light on these prehistoric monuments, thus providing a glimpse of what in our opinion is a paradigm shift in the research of similar monuments throughout Europe.
h i g h l i g h t s Fungal bioreceptivity and biodeterioration of historical glazed tiles models was studied. Tile models with two different ageing degrees (pristine and artificially aged) were tested. 12-month laboratory colonization experiment was conducted with the tiles inoculated with fungi. Biogenic calcium oxalate compounds were formed due to fungal biodeterioration. Bioreceptivity and biodeterioration was not correlated with ageing degree.
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