Ruiniform relief in sandstones: the examples of Vila Velha, Carboniferous of the Paraná Basin, Southern Brazil

Abstract

Vila Velha is a remarkable group of natural sculptures in Palaeozoic
sandstones of the Paraná. Basin in Southern Brazil. The sculptures,
which resemble the ruins of an old stone city, have resulted from the
combination of Cenozoic weathering and erosive processes with the existing attributes of the sedimentary rocks (texture, cementing oxides,
sedimentary and brittle structures). A particular geomorphologic setting
with eroded inselbergs, and a differential iron and manganese cementation
during lateritization phases are other factors controlling that
exceptional landscape, the ruiniform relief. Despite being a natural
heritage of inestimable value, Vila Velha is threatened by large-scale
tourism, with severe risks for its conservation.