Beyond canyons and waterfalls: geomorphological units as geoheritage of Caminhos dos Cânions do Sul Geopark, Southern Brazil

Abstract

<p>Geoheritage comprises a wide range of abiotic elements to which values ​​are assigned. Part of this natural diversity is of geomorphological origin, encompassing mainly geoforms with scientific, turistic, educational and cultural values - the geomorphosites. However, the geomorphological units in which they are inserted are usually considered just as their scenery, that is, they are recognized as geoheritage almost exclusively features in a more detailed scale. Geopark territories where the landscape is an important component of the heritage, the insertion of geomorphological compartmentation is fundamental to understand it. The Caminhos dos Cânions do Sul Geopark (CCSG), located in southern Brazil, is a mosaic of landscapes marked by the presence of a large escarpment that separates other relief units that encompass sites of geomorphological, paleontological and stratigraphic origin of local to international relevance. Canyons, waterfalls, residual hills and ruiniform reliefs are examples of geomorphological sites linked to the different existing compartments. Here we aim to discuss, based on the values ​​of geodiversity, the geomorphological compartments present in the CCSG as part of its geoheritage. The geomorphological subdivision of the CCSG includes five units: (i) the basaltic escarpment of Serra Geral, which separates the (ii) Campos Gerais Plateau from (iii) the Patamares da Serra Geral, intermediate relief between the escarpment and the (iv) Colluvium -Alluvial and (v) Coastal Plains.</p><p>The scientific value, central to the evaluation of geoheritage, has its main attributes in the components of representativeness, integrity and paleogeographic value. All geomorphological compartments are very representative of their morphogenesis and morphodynamics: (i) the Serra Geral escarpment, for example, is strongly dissected, with steep and straight slopes and deep valleys, often in the form of canyons; (ii) the colluvial-alluvial plain, which stands out for the presence of coalescent alluvial fans, whose genesis is linked to the occurrence of mass movements and torrential processes on the escarpment; sometimes also presents river terraces linked to in relative sea-level quaternary fluctuations. The paleogeographic value can also be recognized by the presence of residual hills and interdigitated spurs in the colluvial-alluvial and coastal plains along the entire CCSG territory, which attest to the erosive retreat of the Serra Geral escarpment. Integrity, in turn, is ensured by the coverage area of ​​a relief compartment, especially in inhospitable terrain, such as escarpments. Finally, additional values, such as aesthetics, can be recognized by the scenic beauty provided by the strong topographical contrast between plateau-escarpment or escarpment-plains. In this way, it is understood that it is possible to propose geosites or establish geopanoramic points for observation, being fundamental for the appreciation of one of the main elements of CCSG's geoheritage – the landscape.</p>