Minas Gerais, Brazil
Operator : Equinox Gold (100%)
Sustainability : 2020 ESG Report
Acquisition Date : May 27, 2020 (Effective date: January 1, 2020)
Terms : 1% NSR royalty
The RDM mine is located in Minas Gerais State, Brazil, about 560 kilometres north of the state capital city of Belo Horizonte. The mine area covers approximately 22,600 ha and is accessible by air and road. Vale discovered the Riachos Dos Machados deposit in 1986. CVRD operated the property as an open pit gold mine and heap leach operation until its closure in 1997. The RDM mine remained idle from 1997 until October 2008, when Carpathian gold acquired the mineral rights to the RDM mine and started prospecting and exploration and restarted the mine in March 2014. It was acquired by Brio Gold in April 2016 and subsequently acquired by Leagold in May 2018. The operation is a conventional open pit mine with a 7,000 t/d carbon-in-leach (CIL) plant.
The RDM mine commenced production in early 2014. Average life of mine production at RDM is estimated to be approximately 98,000 ounces of gold per year over a nine-year mine life. For 2020, Equinox Gold expects RDM to produce between 50,000-55,000 oz of gold at AISC of $1,000-$1,050 per ounce of gold sold.
GEOLOGY AND MINERALIZATION
The RDM gold deposit occurs in the north-south trending Araçuaí Fold- Thrust Belt along the eastern margin of the São Francisco Craton, a major Archean-age basement block which underlies more than one million square kilometres in eastern Brazil. The Araçuaí Fold Belt is 15 km to 45 km wide and consists of a series of meta-volcanic/meta-sedimentary rocks of late Archean to late Proterozoic age.
The principal host for the gold mineralization is the quartz-muscovite schist of the Riacho dos Machados Group. The mineralization occurs in a belt of hydrothermally-altered rock developed along a district-scale shear zone. Mineralization occurs in the hydrothermal/shear zone and gold grades are closely related to the sulphide content, especially arsenopyrite.