The environmental factors impact on the conservation of an historic marine quay--a baseline study.

Changes effected by environmental factors on the biological colonization of an historic marine limestone quay were considered, as a baseline study for the monitoring and test plan definition. Environmental factors play a fundamental role in the deterioration of stone monuments, particularly those located in a marine environment. This eighteenth century quay, situated at the Royal Square of the Portuguese capital, is subject to tidal movement, marine aerosol, high levels of pollution and vibration and is partly submerged in polluted water. Part of the quay was dismantled in 1997 and returned to the river water in 2008; since then, progressive (re)colonization by biological organisms has occurred. By means of periodic photographic registry, from 2010 to 2014, the main alterations and deposits on its surfaces were registered. The present paper discusses and presents a vulnerability assessment and monitoring plan for monuments in a marine environment with a view to establishing a preventive conservation plan.

Elemental mapping of Moroccan enameled terracotta tile works (Zellij) based on X-ray micro-analyses.

The purpose of this work is the elemental mapping of enameled terracotta samples (Zellij), produced between the 13th and 20th centuries in Morocco, collected from five different monuments from Marrakech. These pieces were analyzed by two non-destructive micro X-Ray Fluorescence (XRF) spectrometers, aiming to obtain elemental distribution and elemental composition. From the obtained spectra we have identified the main elements present in the tin-opacified lead glaze. The identification of the decoration colors is based on the different ratios between the fluorescence lines of the main component of the glaze (Pb-Lα line) and the fluorescence lines of the main components of the pigment (Co-Kα, Mn-Kα, Ni-Kα,… lines). The semi-quantitative calculations based on these ratios revealed significant differences between modern and ancient samples.

Study of mural paintings using in situ XRF, confocal synchrotron-µ-XRF, µ-XRD, optical microscopy, and SEM-EDS--the case of the frescoes from Misericordia Church of Odemira.

In this work, we present the results of an analytical method developed for detailed pigment identification, stratigraphy, and degradation of the paint layers of mural paintings applied in the study of the 17th century frescoes from the Misericordia Church of Odemira (Southwest Portugal). In situ X-ray fluorescence spectrometry analyses were performed on three panels of the mural paintings and complemented by colorimetric measurements. The different color areas were also sampled as microfragments (approx. 1 mm2) that were studied as taken or mounted in epoxy resin to expose the different paint layers. The microfragments of paint layers and their cross sections were characterized by optical microscopy and scanning electron microscopy coupled with energy dispersive X-ray spectrometry. Furthermore, elemental analysis was obtained with spatially resolved confocal synchrotron radiation µ-X-ray fluorescence spectrometry performed at ANKA synchrotron FLUO beamline. Occasionally, phase analysis by µ-X-ray diffraction was also performed. Results from the different techniques allowed pigment identification and, in some cases, the evaluation of color changes due to degradation processes and, considering the Southern Portugal geology, the identification of their possible provenance. The pigments used were essentially yellow, brown and red ochres, smalt blue, copper green, and black earths, probably from local sources.

Chemical and mineralogical characterization on glazes of ceramics from Coimbra (Portugal) from the sixteenth to nineteenth centuries.

Chemical, mineralogical and textural characterizations were performed on glazed pieces prepared in laboratory as well as on faiences fragments collected from the existing remains in "Santa Clara-a-Velha" monastery (Coimbra, Portugal). The chemical investigation was carried out using micro X-ray fluorescence (micro-EDXRF) and wavelength dispersive X-ray fluorescence (WDXRF); the mineralogical results using X-ray diffraction (XRD) and the textural profile was obtained by scanning electron microscopy coupled with an energy dispersive spectroscopy system (SEM-EDS). Attention has been drawn to the glaze mineralogical changes during the firing temperature process, where three different types of glazes were submitted to three different firing temperatures (800 degrees C, 900 degrees C and 1,000 degrees C). Under these conditions, it is possible to relate the mineralogical content of the fragments to their firing temperature. Furthermore, we focused our purposes on identifying the technological aspects of the ceramic production in Coimbra, such as the raw materials, manufacture techniques and firing temperature adopted for the glaze. The latter aspect is highly dependent on the ceramic materials. In the framework of a more general project, this survey has as premise the recognition of a pattern, which is thought to be exclusively typical from the region of Coimbra. The perspective developed in the present work is towards reliable archaeometric criteria, which can be used to characterise scientifically the ceramics from Coimbra.