Name: Fazenda Brasileiro mine.
Location: The Fazenda Brasileiro mine is located in Bahia state in Brazil, about 180 km north-west of the state capital Salvador.
Holding and Controlling Company: Brio Gold.
Brief Description: Fazenda Brasileiro is an openpit and underground mine with a 30-year operating history of consistent production and reserves replacement.
Brief History: Companhia Baiana de Pesquisa Mineral, the Brazilian federal government geological survey, prospected for alluvial gold along the Itapicurú river in 1969 and 1970.
Base metal-oriented regional stream geochemical surveys were performed in the area by DOCEGEO, the exploration division of Companhia Vale do Rio Doce (CVRD), in 1972.
DOCEGEO/CVRD performed surface exploration programmes from 1976, including significant diamond drilling focusing on the weber belt rocks, that host the Fazenda Brasileiro mine (MFB).
The Fazenda Brasileiro deposit was discovered in the late 1970s by CVRD and production started with an openpit, heap leach gold operation in 1984. Underground operations started in 1988.
In the late 1990s Barrick Gold performed limited work on some properties in the northern Rio Itapicurú greenstone belt (RIGB), which hosts most of the known gold deposits.
Yamana acquired the project from CVRD in August 2003. In December 2014, Brio Gold was established to hold the MFB gold mines, as well as C1 Santa Luz, Pilar and some related exploration concessions, all of which were considered noncore assets within Yamana at that time. On December 23, 2016, Brio Gold became a standalone company in which Yamana currently retains as estimated 85% ownership.
Products: Gold.
Geology/Mineralisation: MFB is located within the RIGB, a 100-km-long, 60-km-wide, north-south-trending volcano-sedimentary belt in the São Francisco Craton.
The structural history of the area is multifaceted, with at least three phases of ductile and ductile-brittle deformation followed by late brittle faulting, which has latterly offset the MFB mineralisation by up to 100 m.
MFB is an epigenetic, structurally controlled and hydrothermally altered Precambrian quartz vein-hosted lode gold deposit that has been subjected to greenschist facies metamorphism.
There is some suggestion of a partial syngenetic origin for the gold because of the anomalous gold content (0.05 g/t gold to 0.10 g/t gold) throughout visibly unmineralised quartz-chlorite schist.
The main mineralisation, in the form of sulphide-bearing quartz veining, is associated with a second deformation event. These multiple vein systems vary in true width from 1.5 m to 40 m, and horizontal mining widths vary from a minimum of 3 m to 40 m.
The veins are generally arcuate, east-west-trending and 40° to 70° south dipping, and have a shallow to moderate mainly east plunge.
Reserves: Total proven and probable reserves as at December 31, 2016, were estimated at 6.62-million tonnes grading 1.96 g/t gold.
Resources: Total indicated resources as at December 31, 2016, were estimated at 2.41-million tonnes grading 3.30 g/t gold.
Total inferred resources as at December 31, 2016, were estimated at 2.55-million tonnes grading 1.91 g/t gold.
Mining Method: Openpit and underground.
Major Infrastructure and Equipment: Openpit mining is undertaken using contractors. The small openpits use air-track drills and backhoe excavators for mining, and highway-type trucks for haulage to the mill.
Access to the underground operation is through a series of declines.
Ore is delivered from the underground mine using articulated 25 t and 35 t Volvo haul trucks.
A 960 000 t/y milling facility, with crushers, a grinding circuit, cyanide leaching and destruction, is used for the recovery of gold.
The MFB also features a paste tailings backfill plant.
The mine also includes a water system that comprises a wellfield, four lined tailings impoundments and power supply from the local grid.
Prospects: Brio Gold completed a large exploration programme at the MFB in 2016, which successfully expanded the resources to replace 2016 production and provide additional future resources.
The 2017 exploration programme is planned to include about 60 000 m of drilling, targeted at the Canto Zone and other high potential areas, near the surface and existing infrastructure. Mineral resource conversion and production will be the focus.
Contact: Brio Gold investor relations.
Contact Details:
Brio Gold
Tel +1 416 860 6310
Email info@briogoldinc.com
Website http://briogoldinc.com