Name: South Arturo mine.

Location: South Arturo is located about 48 km north-west of Carlin, Nevada, in the US.

Mine Owner/s: The South Arturo mine is a joint venture between Barrick Gold Corporation’s wholly owned subsidiary Barrick Gold Exploration (60%) and Premier Gold Mines (40%).

Brief Description: The South Arturo mine is exploiting a Carlin-style disseminated gold deposit using openpit methods, but is now transitioning and expanding to include other openpit and underground deposits.

Mineralisation is found throughout the South Arturo mine area, however, mineral reserves are confined to the Dee pit (Phase 1 – Arturo) and El Niño underground.

El Niño is a high-grade underground deposit being developed out of South Arturo’s completed Phase 2 openpit.

Brief History: Exploration work for barite and gold began in the mine area in 1975. Prospecting exposed barite in several trenches. Cordex Exploration Company conducted exploration activities in the area from 1981 to 1983. While no economic barite was identified, two gold deposits were discovered.

Four major companies – FMC Gold/Meridian Gold Corporation, Dee Gold Mine/Rayrock Mines, GlamisGold, and Barrick – have been responsible for exploration drilling, geological mapping, geophysics and geochemistry that have defined the South Arturo mineralisation.

The Dee openpit mine was put into production by Rayrock in partnership with Dee Gold Mining in 1984. Underground production started in 1999 and continued until December 2000, when openpit and underground operations were shut down and surface facilities were reclaimed.

The South Arturo deposit was discovered by Barrick in July 2005 as a result of drilling beneath the waste disposal facilities of the Dee openpit mine.

The Barrick Dee Mining Venture (BDMV) was established in 1997 when Barrick Gold Exploration entered into an exploration agreement with Dee Gold (then a subsidiary of Glamis), whereby Barrick held 60% and Dee Gold 40%, to explore the Dee mine property outside of the active mining area.

Glamis acquired Rayrock in 1999, and became the operator of the Dee mine. In 2007, Glamis was acquired by Marigold Mining Company, a wholly owned subsidiary of Goldcorp.

In June 2015, Premier completed its acquisition of Goldcorp's 40% interest in the South Arturo mine.

Primary Metals: Gold.

Secondary Metals: Silver.

Geology/Mineralisation: The South Arturo mine is located within the northern Carlin Trend in the Basin and Range physiographic province, in north-eastern Nevada. A sequence of tectonic events have transformed the district into large-scale, north-north-west-trending folds and north-west- to north-east-trending faults, which expose “windows” of the lower tectonic plate rocks within the upper tectonic plate.

The northern Carlin Trend is defined by a north-north-west-trending alignment of gold deposits in a series of these windows. The structural windows in the Carlin Trend from south to north are Carlin, Lynn and Bootstrap. The mine is located within the Bootstrap Window. The oldest formation known near the mine is the Ordovician Hanson Creek dolomite, intersected in a deep drill hole west of the deposit. A 215-m-thick section of Silurian-Devonian Roberts mountains limestone occurs above the Hanson Creek dolomite. The Bootstrap limestone is a grey, massive limestone deposited in a reef margin environment. The Bootstrap limestone is overlain by the Devonian Popovich formation, which is a carbonaceous limestone. The contact between the Popovich formation and Bootstrap limestone is characterised by karst-type dissolution features and brecciation. The upper contact of the Popovich formation grades conformably into the Devonian Rodeo Creek formation. The Rodeo Creek formation comprises siliceous mudstone and silty limestone. The top of the Rodeo Creek is structurally terminated by the Roberts Mountain Thrust and is the top of the lower plate sequence. Upper-plate rocks at the mine consist of a sequence of mudstone, argillite, and bedded cherts of the Vinini, Elder and Slaven Chert formations. The Tertiary Carlin formation, a sequence of tuffaceous sedimentary rocks and air-fall tuff, fills channels and depressions in the Dee mine area. While mineralisation is widespread throughout the South Arturo mine area, there are five zones of high-grade gold mineralization – South Arturo, Dee Deep North, SW Dee, West Button Hill, and Hinge.

Reserves: Total proven and probable reserves as at December 31, 2018, were estimated at 2.84-million tonnes grading 3.01 g/t gold.

Resources: Total measured and indicated resources as at December 31, 2018, were estimated at 9.22-million tonnes grading 1.05 g/t gold. Inferred resources were estimated at 760 000 t grading 1.3 g/t gold.

Mining Method: South Arturo is an openpit and underground operation.

Major Infrastructure and Equipment: Current infrastructure includes an openpit and underground mine, waste-rock storage facilities, roads, a 120 kV powerline with substation, vertical dewatering wells, explosives storage facilities, a fuel bay, and a main gate.

Oxide ore is treated at an oxide mill at Barrick’s Cortez site and the refractory ore is treated at Barrick’s Goldstrike operation.

Prospects: The El Niño underground mine at South Arturo achieved commercial production in October 2019, ahead of schedule and on budget. The construction of the Phase 1 openpit continues.

Barrick is also continuing to conduct drilling programmes to test for possible extensions to the South Arturo mineralisation at depth.

Contact Details:
Premier Gold Mines
Tel + 1 807 346 1390
Email info@premiergoldmines.com
Website https://www.premiergoldmines.com