Geodiversidade da cidade do Natal (RN): valores, classificações e ameaças

Abstract

Geodiversity of the planet is understood by all abiotic resources that make up the nature: soils, minerals, rocks, rivers, lakes, landscapes and natural phenomena such as weathering and magmatism. From this, researchers have focused their studies under this new perspective of geosciences since the 1990s, also taking advantage of the multidisciplinary allowed by geodiversity and disseminating the geological content through the society. In Brazil, the use of the geodiversity term began in the 2000s and has been intensified over the recent years, also applied to the interpretations of the abiotic resources’ use in cities, such as on monuments, streets and buildings. In Natal, capital of Rio Grande do Norte, besides the beautiful landscapes composed by beaches, dunes, cliffs, rivers, wetlands and lakes, there are many records of uses of geodiversity’ resources, especially of rocks in buildings and monuments, historical and recent, and on the first streets of the city. It’s noted the use of sedimentary rocks, such as calciferous and ferruginous sandstones, igneous, especially granite taken from the nearby town Macaíba, and metamorphic, as the marbles related to the Jucurutu Formation. Throughout the history of the city, running through more than 400 years, geodiversity is present since the beginning of the local mapping, dating back to the Dutch occupation period, in which the natural environment was portrayed faithfully. The studies developed in this work addresses the geodiversity of Natal that occurs naturally, in situ, or along with the local cultural heritage, ex situ, in the city’s region. Descriptions of the geodiversity values are made, according to ecosystem services, as defined by Murray Gray, as well as classification of these occurrences, natural or not, according to their values and areal extent. It’s also made some considerations on the major threats to geodiversity that may result on the removal of their characteristics and occurrences in the city.