Name of the Mine
Mara Rosa mine.

Location  
Goiás state, in Brazil.

Mine Owner/s  
Hochschild Mining.

Brief Description  
Mara Rosa is a long-life mining asset located in a mining-friendly jurisdiction.

Brief History  
Hochschild acquired the Mara Rosa project from Amarillo Gold Corporation in April 2022. Construction started shortly thereafter. The mine achieved first production in the first half of 2024. The operation has a more than ten-year life-of-mine.

Primary Metals/Minerals  
Gold.

Secondary Metals/Minerals  
Not stated.

Geology/Mineralisation  
The Mara Rosa district is situated within the Goiás Magmatic Arc (GMA) – a 100-km-wide, north-east-trending granite-greenstone terrane that extends about 700 km – which forms part of the Tocantins physiographic province, an intercratonic mobile belt that separates the Amazonas and São Francisco cratons, located to the north-west and south-east respectively. 

The geology in the Mara Rosa district is principally delineated by three north-east-striking, moderately to steeply north-west-dipping belts of metamorphosed volcanosedimentary and associated intrusive rocks. These belts, referred to as the Western, Central, and Eastern belts, are separated by broad zones of tonalitic orthogneiss. The Eastern belt is bounded to the south-east by the Rio dos Bois fault, which also defines the south-eastern limit of the GMA.

Mara Rosa primarily covers the Eastern belt greenstone assemblage, with some coverage of the Western and Central belts as well. The Eastern belt has a maximum thickness of 6 km, generally strikes to the north-east, and dips moderately to steeply to the north-west.

It occurs in a regional thrust that probably acted as one of the primary dewatering conduits during the Neo-Proterozoic Brasiliano orogeny. The geophysical, geological, and geochemical data available demonstrate that this deposit occurs within a 50 km structural corridor and localised within shear zones associated with potassium alteration and lower order gold-telluride mineralisation.

Reserves  
Total proven and probable reserves as at December 31, 2023, were estimated at 23.81-million tonnes grading 1.2 g/t gold.

Resources  
Total measured and indicated resources as at December 31, 2023, were estimated at 3.3-million tonnes grading at 1.1 g/t gold and 83 g/t silver equivalent. Inferred resources were estimated at 100 000 t grading 0.52 g/t gold and 39 g/t silver equivalent.

Type of Mine
Openpit.

Mining Method  
Conventional truck-and-shovel methods.

Major Infrastructure/Equipment  
The mine includes a processing plant, restaurant, offices, workshops, a control room, laboratory, gatehouse, filter plant and site substation.

Prospects  
Near-mine programmes are in place to discover another more than one-million gold-ounce resource by 2030.

Contact Details 
Hochschild Mining
Tel +44 203 709 3260
Email info@hocplc.com

Sources
Amarillo Gold. Website: https://amarillogold.com/

Hochschild Mining. Website: https://www.hochschildmining.com/
Hochschild Mining. Full year 2023 results (March 13, 2024)