Comparative analysis of coatings on granitic substrates from urban and natural settings (NW Spain)

Sanjurjo-Sánchez, Jorge; Romaní, Juan Ramón Vidal; Alves, Carlos

doi:10.1016/j.geomorph.2011.09.008

Cited by 24 publications

(16 citation statements)

References 39 publications

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“…Rock coatings can form due to biological (Garcia-Vallès et al 1997;Tani et al 2003), physical (Dixon et al 2002, Durocher andSchindler 2011), and chemical processes Sanjurjo-Sánchez, Romaní, and Alves 2012). Three essential processes are required for the development of rock coatings: erosion of an exposed rock surface; transportation of coating components to the host rock surface; and biogeochemical barriers that prevent post-deposition movement of coating components (Dorn 1998).…”

Section: Formation Of Black Coatings Near Base Metal Smeltersmentioning

confidence: 99%

A Landsat-based study of black rock coatings proximal to base metal smelters, Sudbury, Ontario, Canada

Malcolm

Leverington

Schindler

2015

International Journal of Remote Sensing

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Past emission of metal-bearing particulate matter, sulphur dioxide (SO 2 ), and sulphuric acid by base metal smelters in the Sudbury region led to widespread loss of vegetation, contamination of soils, and formation of black coatings on rock surfaces. These black coatings formed through the incorporation of smelter-borne particulate matter into the partly dissolved uppermost layers of siliceous minerals on exposed rock, and are characterized by high heavy-metal content. This study involved assessment of the reflectance properties of black coatings in the Sudbury region, and determination of the geographic distribution of coatings through supervised classification of reflectance data derived from a Landsat Enhanced Thematic Mapper Plus (ETM+) image. Classifications involved the use of the Spectral Angle Mapper (SAM), Maximum Likelihood, and Feedforward Backpropagation Neural Network algorithms. The reflectance spectra of black coatings in the Sudbury region are relatively flat and featureless, and are characterized by reflectance values less than~13% across the visible, nearinfrared, and short-wave infrared. Spectral properties are similar to those of magnetite, a spinel-group mineral known to be present in Sudbury coatings. The presence of carbon-rich soot particles may be an important influence on the reflectance properties of coatings. SAM classification results are characterized by the widespread mislabelling of uncoated urban and open-pit sites as mantled by black coatings, and neural network results problematically mislabel some uncoated wetland sites as coated. Results generated by the Maximum Likelihood algorithm most usefully depict the distribution of exposed black coatings in the Sudbury region. The mapping of black coatings using remote-sensing methods can provide useful information on the spatial character of environmental degradation in the vicinity of smelters, and should be helpful in the monitoring of environmental recovery where emissions have been reduced or eliminated.

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Section: Formation Of Black Coatings Near Base Metal Smeltersmentioning

confidence: 99%

A Landsat-based study of black rock coatings proximal to base metal smelters, Sudbury, Ontario, Canada

Malcolm

Leverington

Schindler

2015

International Journal of Remote Sensing

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“…1), sometimes called 'pathologies' that can be referred to by different designations (see ICOMOS 2008). These decay features could be related to colour and textural changes resulting in the development of diverse types of coatings (Sanjurjo-Sánchez et al 2012). One of the most (in)famous types of coatings is the so-called black crusts (Fig.…”

Section: Pollutants Sources and Decay Processesmentioning

confidence: 99%

Decay effects of pollutants on stony materials in the built environment

Sanjurjo-Sánchez

Alves

2011

Environ Chem Lett

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This review discuss the effects that pollutants have on stony materials applied on the built environment, illustrating different macroscopical products (pathologies) that can affect historical and modern architectural works. The impact of the decay processes is related to the susceptibility of the materials, environmental conditions and the kind of pollutants that degrade building materials. Here are reviewed the main decay processes resulting from the actions of gases, particulate matter and solutions (from wet deposition to capillary rising and including circulating waters such as run-off), showing that besides atmospheric pollution, also pollutants rising from the ground can cause important deterioration on building materials. Following, the use of tracers is considered for the study of pollutant sources and migration, including neoformation minerals (that might also constitute markers of environmental conditions) and chemical tracers, giving special attention to isotopic tracers, namely to proposals regarding the use of some stable and radioactive isotopes for the study of pollutants that have strong potential but have not been tested yet are also presented. At the end of this chapter, some final considerations are made on the problem of durability assessment of materials in the built environment and also on the use of tracers to assess the origin of damaging compounds in the built environment.

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“…From the characterization of the above covering layers and our observations [5][6][7][8][10][11][12], we can state that the components of most of the covering layers on the granite surfaces are partly related to the surrounding environment and clearly formed from exogenic materials, but also include some of the underlying granite minerals [6,11,12]. Thus, they are not necessarily related to the natural ageing of the rock surfaces and the present term patina is not applicable.…”

Section: Discussion and Final Remarksmentioning

confidence: 99%

“…Sampling of coatings on buildings was performed in a similar manner to that described in Prieto et al [5] and Sanjurjo-Sánchez et al [6]. Because covering layers on building surfaces and façades are highly variable, analytical studies and techniques cannot be standardized.…”

Section: Case Studiesmentioning

confidence: 99%

Covering Layers on Granite Buildings of Northwestern Iberian Peninsula: When Observable Characteristics and Lab Characterization Do Not Match

2020

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Illustrated glossaries on stone pathologies help to describe deterioration forms in built heritage without resorting to any laboratory analyses. In this way, terms such as crust, deposit, and soiling which according to ICOMOS-ISCS: Illustrated Glossary on Stone Deterioration Patterns may include exogenic material, a patina which results from ageing of the material in an endogenous process, and a film included under the broad term of a coating layer in the glossary, can be macroscopically identified on site. However, a definition on the basis of characteristics only observable with the naked eye (without further analysis in the laboratory) is certainly complicated, and if in addition, the case studies are on granitic rock (a major building stone used across Europe), the picture becomes even more complicated. The intention of this brief report is to engender an open, constructive debate about the casuistry of the covering layers on granite (a poorly reactive and less porous rock) and the difficulty of using the ICOMOS nomenclature on them.

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Comparative analysis of coatings on granitic substrates from urban and natural settings (NW Spain)

Cited by 24 publications

References 39 publications

A Landsat-based study of black rock coatings proximal to base metal smelters, Sudbury, Ontario, Canada

A Landsat-based study of black rock coatings proximal to base metal smelters, Sudbury, Ontario, Canada

Decay effects of pollutants on stony materials in the built environment

Covering Layers on Granite Buildings of Northwestern Iberian Peninsula: When Observable Characteristics and Lab Characterization Do Not Match

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