An assessment protocol of speleological relevance for natural underground cavities in different Brazilian lithotypes is presented here based on geodiversity elements. The protocol, whose development is based on geoconservation guidelines, aims to contribute to better national speleological legislation regarding determination of speleological relevance. For this purpose, four elements of geodiversity present in natural cavities are considered: their set of geological features (geoforms), their development patterns (shape), dimensions, and hydrological elements. In order that the protocol can be applied in a judicious way, nine analytical parameters are conceptualized here with their weights and contributions numerically defined. The protocol should not, however, be seen as definitive, but a proposal subject to review and update.
