Ediacaran turbidites as geoheritage: Potential of the Itajaí Basin, Southern Brazil

Abstract

Discovery and inventory of geoheritage remain urgent tasks for Brazil. Investigations in the state of Santa Catarina have allowed to realize the uniqueness of exposures of the Ediacaran turbidites of the Itajaí Basin. Their outcrops along the federal highway BR-470 in the valley of the Itajaí-Açu River have been examined to establish four geoheritage sites (geosites), namely Apiúna, Bergamota, Colibri, and Ibirama. Each of them has been studied in regard to the geological context and geoheritage properties. Geological descriptions and the related genetic interpretations of each geosite are provided. It appears that they represent different parts and different aspects of the regional Ediacaran turbidite system. The key localities are true geosites, which can be neither be combined into a single lengthy geosite nor considered as fully separate objects due to their evident similarity. For such kinds of geoheritage, a new idea of geosite series is proposed. The studied geosite series is dominated by sedimentary and paleogeographical geoheritage types, and it can be ranked nationally (the global rank is not excluded). The geosites are linear and point (punctual) sites, and most of them are artificial. A potential danger to them is linked to road maintenance, but there may also be damages from rockfalls, vegetation expansion, and irresponsibility of occasional visitors (rock graffiti and waste storage). A conservation plan should be developed to address these issues. This geosite series demonstrates significant potential for geological research and education linked to the Ediacaran world and turbidite sedimentation. Additionally, it can be exploited efficiently for training university students and company employees in dealing with turbidite hydrocarbon reservoirs. Further geoheritage exploration in the Itajaí Basin and the entire Santa Catarina State is recommended.