The Discovery, Production, and Continued Exploration of the SSX Mine Area, Jerritt Canyon, Nevada

Gold exploration was started in the Jerritt Canyon District, 72 km north of Elko,
Nevada by FMC Corporation in the early 1970’s, and has been nearly continuous to
the present time. Gold production commenced on July 4, 1981, and district-wide production
to date from both open pits and underground operations is in excess of 7 million
ounces. The Jerritt Canyon District is located in the central and southern
Independence Range. It is composed of allocthonous quartzite and sicliciclastic rocks
of the Snow Canyon Formation, and autochthonous Ordovician through Devonian
autochthonous rocks exposed in several structural and erosional windows. The
greater SSX area contains two windows of Ordovician through Devonian Hanson
Creek Formation, Roberts Mountains Formation and overlying Snow-Canyon
Formation. Gold occurs mainly in the Hanson Creek units 1 to 4 and in the Roberts
Mountains Formation. Northwest oriented Pennsylvanian basalt dikes that are spatially
associated with mineralization crosscut the SSX area. The SSX (South Saval
Extension) mine was discovered by mapping and geochemical sampling of road cuts
along the Burns Basin/Pattani haul road. Detailed haul road sampling produced a
15 ppb gold anomaly hosted in an N70W oriented dike. Ahole drilled near the margin
of one of the dikes intersected 22 m of 5 g/ton Au. Another in 1992, intersected 25 m of
19 g/ton Au. Aportal was established in 1996. Over 9 km of drift have since been completed,
and approximately 871,000 oz have been produced. Gold mineralization is
hosted within the Silurian-Devonian Roberts Mountains Formation and Ordovician-
Silurian Hanson Creek Formation units 1–3, at depths of 140–300 m below surface.
Mineralization is structurally and stratigraphically controlled at intersections of
northeast and northwest oriented faults, and localized along the N50W oriented
South Boundary fault that was intruded by a 320 ma dike. Older N70W to N50W
fault sets with near vertical dips are offset by younger N10-50E faults with NW and
SE dips and normal to dip-slip displacements. A northeast oriented, fault bounded,
structural high dominates the east portion of the mine and mineralization is constrained
by faults, lithologic contacts, and the South Boundary dike. The central portion
of the mine is an apparent graben where mineralization is constrained by the
South Boundary dike and at least two sets of major northeast oriented faults that
include the SB fault. The SB fault likely extends from Starvation Canyon to the California
Mountain Pit to the northeast. The western portion of the SSX mine is the
newest area of development. Mineralization is associated with a northwest extension
of the South Boundary dike and northeast oriented faults. Other mineralization may
also be associated with faults parallel to the SB fault located further to the west.Exploration opportunities also exist to the north of current mine development on a
dike set that parallels the South Boundary dike, and to the southwest of the South
Boundary dike.