Ascertaining the degradation state of ceramic tiles : a preliminary non-destructive step in view of conservation treatments

Conserving the cultural heritage is a general concern and the use of non-destructive techniques to characterize ancient materials is important. Serious deterioration effects in environmentally exposed ancient glazed ceramic tiles arise from the development of micro-organisms (algae/fungi) within the pore system. Subsequent biodegradation processes are particularly harmful once the decorated glaze is damaged by exfoliation/detachment. Three case studies will be addressed: Portuguese polychrome decorated tiles from the interior of two churches (16th–17th century) and from the outdoor of a Palace (18th century). Small tile fragments were directly irradiated in a wavelength-dispersive X-ray fluorescence spectrometer for glaze chemical characterization and subsequently irradiated in a powder diffractometer to assess the phase constitution of both glaze and ceramic body. Cleaning and conserving these ancient cultural artifacts involve a decontamination process applying innovative non-destructive techniques. The present work is intended as a contribution to diagnose the actual degradation state of ancient tiles in view of future decontamination actions using gamma radiation

Diagnosis of pathologies in ancient (seventeenth-eighteenth centuries) decorative blue-and-white ceramic tiles : Green stains in the glazes of a panel depicting Lisbon prior to the 1755 earthquake

Decorative panels of ceramic glazed tiles comprise a valuable cultural heritage in Mediterranean countries. Their preservation requires the development of a systematic scientific approach. Exposure to an open-air environment allows for a large span of deterioration effects. Successfully overcoming these effects demands a careful identification of involved degradation processes. Among these, the development of micro-organisms and concomitant glaze surface staining is a very common effect observed in panels manufactured centuries ago. This paper describes a study on the nature of green stains appearing at the surface of blue-and-white tile glazes from a large decorative panel with more than one thousand tiles, called Vista de Lisboa that depicts the city before the destruction caused by the 1755 earthquake. The characterization of green-stained blue-and-white tile glazes was performed using non-destructive X-ray techniques (diffraction and fluorescence spectrometry) by directly irradiating the surface of small tile fragments, complemented by a destructive scanning electron microscopy (SEM) observation of one fragment. Despite the green staining, analytical X-ray data showed that no deterioration had occurred irrespective of the blue or white color, while complementary SEM-EDX data provided chemical evidence of microorganism colonization at the stained glaze surface

Rare earth elements - Source and evolution in an aquatic system dominated by mine-Influenced waters

Acid mine drainage (AMD), formed by the instability of sulfides, typically generates acidity and releases potentially toxic elements and sulfate to the environment, among other pollutants. An example is the group of rare earth elements (REE) that may have high toxic behavior. This toxicity leads to degradation of soils, water reservoirs and rivers, promoting serious risks for the ecosystems. So, the main goal of the present work is to study the hydrochemical properties of a system with mine-influenced waters during the rainy season, focusing on the origin, evolution/behavior, and concentration of REE. The study area is the São Domingos mining complex, located in one of the largest metallogenetic provinces in the world (Iberian Pyrite Belt), known by the evidences of AMD contamination. The obtained results reveal extraordinarily low pH (0.4), high electrical conductivity, reaching 26,200 μS/cm, and high values of sulfate and acidity. Regarding the REE, the determined concentration exceeded that observed in normal pH of neutral freshwaters by 2-3 times the order of magnitude. The results revealed that Y and Ce are distinguished in practically all sampled sites, due to its higher concentrations, with maximum values of 221.8 and 166.9 μg/L. In general, the concentrations increase as the water pH decreases. The statistical analysis indicates that REE elements may have a common origin, mutual dependence, and similar behavior during transport with typical AMD elements and composition of host rocks. Most samples show enrichment in middle REE (MREE) (Gdn/Lun), like the classic signature of AMD. In turn, colloids and AMD-precipitates may be participating in the incorporation of these elements. Therefore, due to potential risk of impacts on ecosystems, REE are a topic of relevant interest for future studies in order to assist monitoring processes and help government decisions related to water quality management.Patricia Gomes acknowledges FCT (Science and Technology Foundation, Portugal) by the research fellowship under the POCH (Programa Operacional Capital Humano) supported by the European Social Fund and National Funds of MCTES (Ministerio da Ciencia, Tecnologia e Ensino Superior) with reference SFRH/BD/108887/2015. This work was co-funded by FCT through projects UIDB/04683/2020, UIDP/04683/2020 and Nano-MINENV 029259 (PTDC/CTAAMB/29259/2017) . The authors are grateful to the anonymous reviewers for their valuable contributions to improving the manuscript

Produção e consumo de cerâmica islâmica em Lisboa: conclusões de um projecto de investigação

Peer reviewe

Thorium and Uranium distribution in a passive system for mine water treatment

The abandoned Jales mining area is a sulphide-rich deposit (Northeast of Portugal). Acid mine drainage resulted from oxidation of sulphides is treated in a passive system with wetlands. The present work studies the thorium and uranium behaviour in the water and in the fine fractions of wetland soils throughout the passive treatment system. The evaluation of the efficiency of the all system was done determining metals concentration variation in the creek water upstream and downstream of the treated effluent discharge. The results point to higher efficiency to retain Th after summer than after winter. The opposite was found for uranium, which increases significantly in the creek water after summer and, in a lower extent, after winter. Also, Th and U have a tendency to increase in the fine fractions of the wetlands soils after summer, which can be explained by the longer water-soil contact/lower water dynamics. Nevertheless uranium has a much higher tendency to be in solution as revealed by a high concentration in the porewater of wetland soils. A relation of these actinides behaviour with the Fe and Mn distribution is not clear.- Thanks are given to EDM, S.A. for providing access to the water treatment plant, FCT (Portuguese Science and Technology Foundation, UID/Multi/04349/2013, and COMPETE 2020 (Programa Operacional da Competitividade e Internacionalizacao), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145-FEDER-007690 and project Nano-MINENV number 029259

Geochemial patterns and firing technology research on ceramic glazed tiles from the 17th-20th centuries (Lisbon region, Portugal)

A set of 17th – 20th century glazed tiles supplied by the Department of Cultural Heritage tile collection, Lisbon City Hall, is studied in this work. The tiles were described and classified in a chronological point of view and analytical work includes chemical and mineralogical characterization of the ceramic bodies and mortars by instrumental neutron activation analysis and X-ray diffraction. Most tile bodies consist mainly of quartz, gehlenite and calcite in variable proportions; commonly these main phases are accompanied by high temperatures phases, namely wollastonite or diopside, pointing to a Ca- or Mg-rich raw material, and mullite (in one sample) indicating the use of non-carbonated raw materials. Small amounts of K-feldspar and hematite are present in most tiles, whereas analcime, plagioclase, vaterite and cristobalite are found in just a few samples. Chemical composition points to a certain homogeneity within 18th century tile bodies; the 20th century samples analysed are heterogeneous and have a different rare earth elements (REE) pattern, two are enriched in the first transition row elements, pointing to higher amounts of ferromagnesian minerals, and the other has lower amounts of Na, Fe, Cr and Co, and higher of Cs, light rare earth elements (LREE), Th and U suggesting high aluminium silicates content. The 17th century samples have a more heterogeneous chemical composition and higher contents of As and Na, which is explained by the presence of analcime. The ancient tiles have a general depletion of chemical elements, probably due to a dilution effect of the higher calcite content. The mortars are all lime rich, but the 20th century ones have a general enrichment in all elements, and more k-feldspar and mica.info:eu-repo/semantics/publishedVersio

A haliêutica no Período Romano: a fábrica da Casa do Governador da Torre de Belém

A partir de uma intervenção arqueológica de contrato realizada pela ERA-Arqueologia S. A. no lugar da Casa do Governador da Torre de Belém, em Lisboa, foi identificada uma grande unidade de produção de preparados de peixe da Época Romana. A relevância do local suscitou a criação de um projecto de investigação, que obteve financiamento da FCT, que tem por objectivo estudar o sítio em si, no contexto da economia do estuário do Tejo e, em âmbito mais lato, a sua inserção nas rotas atlânticas de circulação de produtos no Período Romano. A abordagem multidisciplinar desenhada pretendeu estabelecer as melhores estratégias para encontrar respostas ao questionário científico elaborado. Assim, para além do estudo arqueológico da unidade de produção propriamente dita (fases de construção, remodelação, transformação e abandono), da natureza dos artigos ali fabricados, pelo estudo arqueozoológico do remanescente da produção e da inserção da unidade de produção de preparados de peixe na economia do estuário do Tejo, mediante a identificação arqueométrica da(s) origem(ns) das ânforas ali encontradas, particularmente as produzidas na Lusitânia. Apresenta-se um ponto de situação das investigações em curso, incidindo, em primeiro lugar, nos aspectos relacionados com a estrutura da unidade de produção e os seus ciclos de ocupação. Como sempre sucede nestes casos, estamos mais bem informados sobre as fases finais de laboração do que sobre as etapas iniciais, razão pela qual se ensaiaram algumas acções de datação de sedimentos e argamassas. O conjunto dos restos faunísticos começou a ser tratado, designadamente, a ictiofauna e a malacofauna. Pretende-se determinar a natureza dos produtos fabricados. É já claro que estamos perante um artigo que usava esmagadoramente a sardinha e os indicadores da malacofauna evidenciam também a recolecção de algumas espécies, presumivelmente alimentos destinados ao consumo de quem ali laborava, embora se não possa excluir o seu uso na confecção dos artigos produzidos na unidade. Afastada ficou a possibilidade desta recolecção se destinar a uma actividade subsidiária de tinturaria. De entre o conjunto das ânforas, presumivelmente utilizadas para transportar os artigos alimentares produzidos, é possível afirmar que são provenientes de olarias do baixo Tejo, embora seja igualmente clara a presença de uma nova olaria ainda não identificado. A continuidade do estudo incidirá na abordagem arqueométrica da cerâmica comum, para além da continuação das acções em curso que procurarão caracterizar a inserção da unidade de produção nos quadros regionais e globais da província e Império Romano. O Projecto PTDC/HAH/74057/2006 resulta de uma parceria entre o Centro de Arqueologia da Universidade de Lisboa (Uniarq), o Grupo de Geoquímica Aplicada & Luminescência no Património Cultural (GeoLuC) do Instituto Tecnológico e Nuclear (ITN) e a empresa ERA-Arqueologia.In the context of a contract excavation done at Casa do Governador da Torre de Belém, Lisbon, a large Roman fish processing factory was found. The site’s relevance originated a multidisciplinary research project funded by FCT (the Portuguese national agency for research) aiming to study the archaeological site in the context of Tagus’ estuary economy in Roman times, but also in the wider context of the Atlantic foodstuffs production and diffusion. Besides the site’s archaeological study (building phases, transformations and abandonment) we aim to know the nature of the product made (by the archaeozoological study of the processing remains) and also the insertion of the factory within the Tagus estuary’s economy, by the archaeometric study of the local amphorae used to transport the final product. The paper presents the actual research achievements, such as the issues related with the occupation phases and chronology, as usual in these sites we have an overrepresentation of the latter phases and less information about the ancient ones, that’s why we essay some dating methods on mortar samples and sediments by OSL. The archaeozoological research begins with ictiofaunal and malacofaunal remains aiming to understand the nature of the products processed at the factory. It is clear that in Late Antiquity a fish condiment based on sardine was made and all the malacofaunal remains suggest a small recollection activity perhaps just related to the local workers consumption. No signs were found for any other complementary dyeing activity related to the factory. The archaeometric study of local amphorae found at the factory and presumably related to the transport of the fish condiments produced there, allows the conclusion that they came from several of the already known potteries from the lower Tagus but it was possible to identify a new unknown pottery centre. Future research will deal with the archaeometric study of common ware and the analysis of the local, regional and global insertion of Tagus estuary’s fish condiment production within the Roman Empire. The PTDC/HAH/74057/2006 Project is a joint researche project from Centro de Arqueologia da Universidade de Lisboa (Uniarq) Grupo de Geoquímica Aplicada & Luminescência no Património Cultural (GeoLuC) from Instituto Tecnológico e Nuclear (ITN) and Era-Arqueologia S.A. enterprise.info:eu-repo/semantics/publishedVersio

The adaptation of the main floor of the Palace Melo e Abreu (18th century) to an infirmary of the old asylum of mendicity: history and tile panels compositional characterization

Due to its sunny location and mild climate, the hill of Sant'Ana in Lisbon was, since early times, the place of construction of religious and civil buildings. In the eighteenth century, near the former Santo António dos Capuchos Convent (later Hospital – HSAC), a Baroque palace was erected and later on rebuilt by the Melo e Abreu family (later Condes de Murça in the 19th century), whose noble rooms were decorated by a set of high quality tiles, concerned with iconographic and plasticity aspects. The transfer of the Melo e Abreu family to the parish of Santos-o-Velho and subsequent founding of the Asilo da Mendicidade, allowed the purchase of the building in order to expand the assistance space. Currently, the palace serves hospital’s needs, with all the constraints resulting from the cohabitation between cultural heritage and professional medical care day life. Thus, Palace Melo e Abreu is a good case study, not only for the functional changes that it has been subjected to, but also for the rehabilitation measures for structural restoration and conservation made over time. For the assessment of its importance in terms of both heritage and scientific history, we will present an interdisciplinary study, including History of Art and Archaeometry; In this work (together with the history of the adaptation of the main floor of the Palace Melo e Abreu to an infirmary of the old asylum of mendacity) a first stage of the archaeometric approach is presented, comprising the compositional characterization (chemical and mineralogical) of both mortar and glazed tile body of selected panels. We believe that this paper will promote a deep reflection about the safeguard and future heritage policies of this kind of Lisbon's hospitals.info:eu-repo/semantics/publishedVersio