Geological and mining heritages in the Seridó UNESCO Global Geopark: Ediacaran to Cambrian mineral deposits revealed by historical mines in Northeast Brazil

Abstract

The coexistence of mining, geoparks, and conservation is an ongoing discussion for the implementation and development of UNESCO Global Geoparks (UGGps). The Seridó UGGp provides a classic example where mining plays a fundamental role in unveiling geological heritage, showcasing positive relationships between mining and the establishment of sustainable territories based on geoconservation. The aim of this paper is to investigate, within two geosites of the Seridó UGGp—Mina Brejuí and Açude Boqueirão—how geological heritage has been showcased in active mines, correlated with cultural mining heritage, and utilized in geotourism and geoeducation. The paper utilizes adapted geological heritage inventories and valuing techniques, integrating cultural aspects of the mining landscape to provide detailed insights into the complex areas of the geosites. Both geosites have been the sites of regionally significant Ediacaran-Cambrian magmatic-hydrothermal deposits since the early 20th century, yielding metallic and non-metallic raw materials during the World Wars up to the present days. The Mina Brejuí geosite boasts one of the best exposures of W–Mo skarn mineralization in South America within its underground galleries. Açude Boqueirão is a mining district with several types of quarries and mines, and its geoheritage is linked to the initial descriptions of the Borborema regional pegmatitic province with Cambrian Ta–Nb, Li–Be, gemstones, and ornamental deposits, and also for the rare deposit of blue tourmaline gemstone. Particularly, the Boqueirão site requires valorization interventions, as its rich mining heritage is threatened by the expansion of the energy sector and illegal artisanal mining. Active mining operations could present a plethora of opportunities that encompass the geopark's concepts of conservation, tourism, and education. Inventories of mining heritage in geoparks serve as alternative sources for geotouristic routes.