Geo‐mining heritages of the Mariana anticline region, southeast of Quadrilátero Ferrífero‐MG, Brazil : qualitative and quantitative assessment of Chico Rei and Passagem mines.

Abstract

The main gold deposit discoveries in Minas Gerais during the colonial period occurred in the Mariana Anticline region, southeast of the Quadrilátero Ferrífero. Since then, it has been the target of gold extraction and exhaustively studied, which

has given the region great signifcance. This paper describes and makes a quantitative assessment of Chico Rei and Pas- sagem geo-mining heritages. These geo-mining sites show the important geological processes of the earth’s crust during the

Paleoproterozoic and Neoproterozoic, and the gold mining history, through its methods and techniques used in two distinct historical periods. Gold deposits occur along the main mineralized zone on the stratigraphic levels of the Caraça and Itabira groups. In the Chico Rei Mine, gold mineralization occurs mainly as quartz-sulfde veins hosted in the itabirites of Cauê Formation. Its operation marks the colonial period, where slave labor was used to mine gold with rudimentary techniques

and also when geological knowledge was not satisfactory. In the Passagem Mine, gold mineralization is stratiform tourma- linites and quartz-tourmaline-sulfde veins hosted in Batatal Formation. The Passagem Mine, created in 1819, represents

the imperial period, marked by the opening of the Brazilian ports, bringing geological knowledge and new techniques for decadent gold production, through its greatest exponent in the region, the Baron of Eschwege. The quantitative evaluation of the Chico Rei and Passagem mines using the GEOSSIT platform shows us that the two geosites have international scientifc relevance, national relevance for educational and tourist use, and low risk of degradation.