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Geosite ID: PSt05 Name: Serra de Dentro Thematic category: Litology and sedimentology |
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Municipality: Porto Santo Civil parish: Porto Santo Location area: 0.1-10 ha Coordinates(1):33°04'52.10'' N 16°18'33.90'' W Altitude: 87 m Accessibility: Easy Distance to nearest paved road: 0 m Conditions of observation: Good (1) Coordinates of the geosite and / or the best viewpoint |
Brief description
The extensive deposits of greenish clay that arise here are locally designated "Salão" or "Massapez". They are smectitic clays that result from the alteration of submarine volcanoclastic materials (hyaloclastits) that were formed during the seamount stage. These deposits are cut and traversed by a large network of dark basaltic dykes that act as a supporting structure that minimizes the impacts of erosion. The presence of metamorphic aureoles is evident in the contact zones between the dikes and the clay. These sedimentary structures are rich in clayey and silty components and present desiccation cracks or shrinkage due to water evaporation. This is a place of both regional and national relevance, given the origin, nature and chemical composition of the clay deposits, unique in Portugal. The "Salão" is part of the popular architecture of Porto Santo because it was used, for decades, in the typical coverage of the "houses of salão" before the introduction of ceramic tiles.
Relevant notes
Visiting a site of geological interest is the sole responsibility of the user.
The user must take precautions when visiting the site, taking into account the conditions of the terrain, weather conditions and other hazards, so that they do not create situations that put themselves or others at risk.
The user must respect private property. Access to private areas requires prior authorization from the owners.
The user must respect natural heritage, keeping it intact. The impact of your actions should be minimal.
How to Cite
FERREIRA, M. R. (2014). Património Geológico da Ilha do Porto Santo e Ilhéus Adjacentes (Madeira): Inventariação, Avaliação e Valorização como Contributo para a Geoconservação. Dissertação de Mestrado em Vulcanologia e Riscos Geológicos. Departamento de Geociências da Universidade dos Açores. In: https://geodiversidade.