Search results for "Crusts"

Petrographic and geochemical characterization of the Middle‒Upper Jurassic Fe–Mn crusts and mineralizations from Monte Inici (north-western Sicily): …

2021

AbstractFe–Mn concretions and mineralizations, associated with condensed horizons and hardground, are significant archives in ancient carbonate rocks. Their petro-chemical study allows an assessment of the palaeoenvironmental context in which they were formed also connected to their biotic or abiotic origin. At the western side of the Monte Inici (Fornazzo section, north-western Sicily) a well exposed outcrop of condensed pelagic limestones (Rosso Ammonitico facies: Middle‒Upper Jurassic) is well-known and thoroughly studied. In this section, the base of the Rosso Ammonitico facies consists of a very condensed level rich in fossils with a variable thickness deposited from the early Bathonia…

BIOCLEANING

2017

Cleaning is one of the first and most important steps in conservative restora- tion intervention, as it removes the unwanted layers of dirt and deposit from the surface of an artefact. It must be done selectively, however, by adapting the cleaning operation to the different zones and removing successive layers of deposit without acting directly on the original materials of the surface. Generally, cleaning protocols are based on chemical or physical procedures with potential negative effects for restorers’ health and/or for the materials constituting the artworks. As an alternative, solvent gels, rigid gels and resin soaps can be used for selective cleaning. In recent decades, biological cle…

Environmental impact on historical monuments: The black crusts of the Venice lagoon

2020

Black crusts are typical decay forms on calcareous rocks in polluted urban environments. Their origin is due to “sulphation” reaction of calcium carbonate substrates (CaCO3), as a consequence of pH value decrease caused by SO2 in the polluted atmosphere. They can be therefore defined as a passive air pollution sampler. For the purpose of this work, samples from the historic center of Venice were analyzed. The city of Venice suffers in particular maritime and industrial pollution (Marghera industrial zone). By means of minero-petrographic and geochemical analyses, it was possible to obtain information on the mineralogy of the crust and its interaction with the underlying substrates, other th…

Características de las costras físicas y biológicas del suelo con mayor influencia sobre la infiltración y la erosión en ecosistemas mediterráneos

2010

28 páginas, 4 figuras, 5 tablas.

Natural and anthropogenic sources of total suspended particulate and their contribution to the formation of black crusts on building stone materials …

2012

Blackening and disaggregation of exposed surfaces of stone monuments are well-known effects of stone decay taking place in polluted urban environments all over the world. This paper aims to assess the contribution of natural and anthropogenic sources of total suspended particulate (TSP) causing permanent damage (black crusts) to the stone monuments of Catania (Sicily), one of the most popular ‘‘cities of art’’ of southern Italy. Atmospheric pollution of Catania, a typical Mediterranean coastal town, is mainly contributed by vehicle exhaust emissions rather than industrial ones. Episodically, the city also suffers gaseous and ash emissions (plumes) from the nearby Mount Etna volcano. Thus, t…

Morphological determination of the phototrophic community composition of biological soil crusts in coastal sand dunes in northern Germany

2022

This dataset comprises the microbial community composition of biological soil crusts in north-German sand dunes. For this we obtained enrichment cultures of phototrophic microorganisms, by placing fragments of biocrusts of the same Petri dishes as used for sequencing, in Petri dishes with Bold Basal (1N BBM) agarized medium (Bischoff and Bold 1963). Cultures were grown under standard laboratory conditions: with a 12-hour alteration of light and dark phases and irradiation of 25 μmol photons m-2 s-1 at a temperature 20 ± 5 ºС. Microscopic study of these raw cultures began in the third week of cultivation. Morphological examinations were performed using Olympus BX53 light microscope with Noma…

Multidisciplinary Approach for Evaluating the Geochemical Degradation of Building Stone Related to Pollution Sources in the Historical Center of Napl…

2020

Natural stones have represented one of the main building materials since ancient times. In recent decades, a worsening in degradation phenomena related mostly to environmental pollution was observed, threatening their conservation. The present work is focused on the minero-petrographic and geochemical characterization of black crust (BC) samples taken from the historical center of Naples, after selecting two pilot monumental areas. The latter were chosen based on their historical importance, type of material, state of preservation and position in the urban context (i.e., high vehicular traffic area, limited traffic area, industrial area, etc.). The building materials used and their interact…

A multi-analytical approach for the characterization of black crusts on the facade of an historical cathedral

2020

Abstract This study focuses on the characterization of black crusts collected from the Monza cathedral located in the homonymous city (N Italy), a hot spot from the point of view of the atmospheric pollution. Black crusts and substrate marble specimens were analyzed by a multi-analytical approach including X-ray Diffraction (XRD), Fourier Transform-Infrared spectroscopy (FT-IR), Stereomicroscopy (SM), Polarized Light Microscopy (PLM), High Resolution Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy (HRSEM-EDX) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP/MS). The characterization of the carbon fraction (organic carbon, OC, and element…

Contribution of total suspended particulate (TSP) to the formation of black crusts on building materials in urban enviroments of Sicily (Italy)

2011

Metals distributions within black crusts sampled on the facade of an historical monument: The case study of the Cathedral of Monza (Milan, Italy)

2019

This research deals with the characterization of black crusts collected from Dome of Monza. Black crusts (BC) can be formed as a result of different chemical and physical reactions between the stone surface and environmental factors (such as gaseous pollutants, aerosol particulate matter and its specific chemical constituents-the carbonaceous fraction and the metals); therefore, they are considered as a passive sampler of pollutants. The specific focus of the current work is the study of the metals and their distribution within the samples. To characterize BC, several techniques were used such as: HRSEM-EDX, IC and LA-ICP/MS. This integrated approach allowed us to gain information about the…