Geodiversity in Ecclesiastical Construction: a Geotourism Itinerary in the City of Rio de Janeiro

Ecclesiastical geotourism is a branch of urban geotourism since Christian churches have been typically constructed with a wide variety of dimension stones. The geological heritage and the geoscientific dissemination of the lithological types found can reveal information about the spaces’ history, architecture, and culture. As a result, the present study describes the stones used in ten churches in the city of Rio de Janeiro, resulting in an ecclesiastical geotourism itinerary. In addition, information about the weathering of these stones was also studied. The ten churches were selected based on rock diversity, fossil content, and historical and cultural aspects. The primary stones found were limestone (Lioz, Rosso Verona, Negro de Mem Martins, Botticcino), marbles (Jacarandá, Carrara, Bardiglio), augen gneiss (Gnaisse Facoidal), and Leptinite. The fossil content includes rudists (Radiolitides and Caprinula), gastropods (Neoptyxis), ammonoids (Hildoceras), stromatolites, and solitary corals. The main problems observed in the stones were natural weathering over time, pollution and acid rain (on limestone façades), salt efflorescence, biological colonization, black crusts, loss of matrix, graffiti, and mechanical breaks of edges and corners. By disseminating the geodiversity present in these structures, it will be possible to obtain a new approach to these spaces, adding more geotourism value to the city of Rio de Janeiro.