Two UNESCO sites belong to the Panamanian isthmus. Specifically, on the North coast, examples of military fortifications face the Caribbean Sea: the Fortresses of Portobelo Bay and Fort San Lorenzo (XVII-XVIII cent.); while, on the opposite shore, the first Spanish settlement arises on the Pacific Ocean: the nowadays called Monumental site of Panamá Viejo (XVI cent.). In order to improve the knowledge on the materials characterisation and to evaluate the state of conservation related to the environmental impact, specimens sampled at the sites underwent mineralogical-petrographic, physical and chemical analyses (Stereomicroscope, PLM, XRPD, SEM-EDX, XRF, MIP and IC), highlighting at Panamá Viejo, masonries mainly composed of polygenic breccias, tuffites, basaltic andesites, rhyolites and sporadic rhyodacites. Considering Portobelo fortifications, coral limestones and sandstones have been identified as principal building materials, while basaltic andesite has been observed only at Fuerte de San Fernando. Finally, at Fuerte de San Lorenzo, tuffites and grainstones have been detected in the masonries; these latter ones were mainly utilized for realizing corners (as ornamental parts of the portals and the base blocks). Furthermore, potential quarries of raw materials have been identified and sampled, in order to define the provenance of the stones employed in the fabrication of buildings, and to compare the differences between the preservation of the rocks utilized in the masonries with the outcropping ones. Lastly, this study allowed us to investigate the past, present and future interaction between these materials and the environment, utilizing dose-response functions for evaluating the damages due to the surface recession, salts cycles and biomass growth.
Investigation on construction materials and their environmental interaction at the Panamanian UNESCO sites
CIANTELLI, Chiara;Alessandro Sardella;VACCARO, Carmela;
2017
Abstract
Two UNESCO sites belong to the Panamanian isthmus. Specifically, on the North coast, examples of military fortifications face the Caribbean Sea: the Fortresses of Portobelo Bay and Fort San Lorenzo (XVII-XVIII cent.); while, on the opposite shore, the first Spanish settlement arises on the Pacific Ocean: the nowadays called Monumental site of Panamá Viejo (XVI cent.). In order to improve the knowledge on the materials characterisation and to evaluate the state of conservation related to the environmental impact, specimens sampled at the sites underwent mineralogical-petrographic, physical and chemical analyses (Stereomicroscope, PLM, XRPD, SEM-EDX, XRF, MIP and IC), highlighting at Panamá Viejo, masonries mainly composed of polygenic breccias, tuffites, basaltic andesites, rhyolites and sporadic rhyodacites. Considering Portobelo fortifications, coral limestones and sandstones have been identified as principal building materials, while basaltic andesite has been observed only at Fuerte de San Fernando. Finally, at Fuerte de San Lorenzo, tuffites and grainstones have been detected in the masonries; these latter ones were mainly utilized for realizing corners (as ornamental parts of the portals and the base blocks). Furthermore, potential quarries of raw materials have been identified and sampled, in order to define the provenance of the stones employed in the fabrication of buildings, and to compare the differences between the preservation of the rocks utilized in the masonries with the outcropping ones. Lastly, this study allowed us to investigate the past, present and future interaction between these materials and the environment, utilizing dose-response functions for evaluating the damages due to the surface recession, salts cycles and biomass growth.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
