The mineral deposits along the Carlin Trend form a suite of deposits known as Carlin-type. Carlin deposits comprise stratabound disseminated gold mineralization hosted by Silurian-Devonian carbonate rocks that have been metamorphosed to varying extents. The deposits are hydrothermal in origin and are usually structurally controlled.

Gold deposits of the Leeville underground Complex are hosted by lower Paleozoic carbonates of the Devonian Rodeo Creek Formation (Drc), Devonian Popovich Formation (Dp), and Siluro-Devonian Roberts Mountains Formations (SDrm), and a series of highly altered, undifferentiated dikes cross cutting stratigraphy.

Gold mineralization is controlled by a combination of lithology and structure. Intrusive rocks occur as dikes and sills, and locally host mineralization. Lithologic hosts include Rodeo Creek, Popovich, and Roberts Mountains Formations that vary between sub-horizontal to moderately folded. Mineralized material consists of 60 – 90% quartz, 5 - 20% kaolinite, 1 - 17% carbonate, and 3 – 7% pyrite. Gold mineralization in the Leeville complex is wholly refractory.

The Carlin Complex has three major operating underground mines including Goldstrike underground, Leeville and the Portal Mines (including Pete Bajo and Exodus/Northwest Exodus). All mines utilize drift and fill and/or long-hole stoping and are accessed by shaft or portals.

The mining method primarily used on the West Leeville orebody is longhole stoping with typical stopes of dimension 30.5 metres (100 ft) long, 9.1 metres (30 ft) wide and 18.3 metres (60 ft) high. The mining methods employed at the Turf orebody are longhole stoping and underhand cut and fill, depending on what geotechnical constraints allow. Stope geometries for the Turf orebody follow the same constraints as the West Leeville orebody. In the cut and fill areas of the Turf orebody, 4.6 to 5.2 metres (15 to 17 ft) wide primary and secondary drifts will be cut in four 4.6 to 6.1 metres (15 to 20 ft) high lifts, designated A-D.

The Four Corners orebody is designed to be mined with the same methods as those being used on the Turf orebody, but a geotechnical evaluation is being performed to determine mining method improvement. The maximum stope dimensions for the Four Corners orebody have been set at 30.5 metres (100 ft) long, 6.1 metres (20 ft) wide, and 24.4 metres (80 ft) high. In Four Corners orebody cut and fill areas, only 20-ft wide primary drifts will be cut in 4.6 to 6.1 metres (15 to 20 ft) high lifts, A-D.

The Leeville Complex utilizes three forms of backfill:
• Ce ........

- subscription is required.