Geological and historical aspects and conservation status of the fortifications of the Santos region on the coast of São Paulo State

Abstract

Military fortifications were built at strategic locations in Brazil for the purpose of defending the territory. Currently, many of them are protected by law as representatives of the colonial period and are used for tourist purposes. The aim of this study is to identify the types of stones used in the construction of military fortifications built between sixteenth and twentieth centuries on the coast of São Paulo State within the municipalities of Bertioga, Guarujá and Praia Grande and infer the probable origin of these stones. Identification of the type of material used in these constructions allows a better understanding of the history, culture, technical and geodiversity at the time of their construction. The evaluation of their condition and current use is intended to support actions to which the fortifications may be submitted in order to preserve and maintain the cultural heritage in stone. The fortifications were constructed mainly with granites and gneisses that crop out in the region. Although some of them are listed by the National Institute for Historical and Artistic Heritage (IPHAN) and are the focus of tourism, some of them are deteriorated and require repair in order to conserve and preserve these fortifications, which represent a period in the defense of the State of São Paulo.