The Casino deposit is unusual amongst Canadian porphyry copper
deposits in having a well-developed enriched blanket of secondary
copper mineralization similar to that found in deposits in Chile
and the southwestern United States, such as the Escondida and
Morenci deposits. Unlike other Canadian porphyry deposits, the
Casino deposit’s enriched copper blanket was not eroded by glacial
action. At Casino, weathering during the Tertiary Period leached
the copper from the upper 70 m of the deposit, forming the leached
cap, and re-deposited it
lower in the deposit, forming the supergene enrichment zones. This
created a layer-like sequence consisting of an upper leached zone
up to 70 m thick, where all sulphide minerals have been oxidized
and copper removed, resulting in a bleached, limonitic leached cap
containing residual gold. Beneath the leached cap is a zone up to
100 m thick of secondary copper sulphide mineralization, primarily
chalcocite and minor covellite, and including thin, discontinuous
units of supergene copper oxide mineralization directly underlying
the leached cap. The copper grades of the enriched, blanket-like
zone can be up to twice that of the underlying unweathered hypogene
zone of primary copper mineralization, the latter comprising
pyrite, chalcopyrite and lesser molybdenite. The hypogene copper
mineralization is persistent at depth, extending more than 600 m
below surface, and beyond the deepest drill holes.
In 2009, Quantec Geoscience Limited of Toronto, Ontario performed
Titan-24 DC/IP surveying,
as well as an MT survey over the entire grid. MT surveys provide
high resolution and deep penetration (to 1 km), and the Titan DC/IP
survey provides reasonable depth coverage to 750 m.
In 2010, all of Pacific Sentinel’s historic drill core stored at
the Casino Property was re-logged to provide data for the new
lithological and alteration models.
In 2011 Western focused on geotechnical, metallurgical and baseline
environmental studies, but also drilled several exploration holes,
prior to changing its name to Western Copper and Gold Corp
(Western), and creating its wholly owned subsidiary, Casino Mining
Corporation (CMC) late that year. In 2011, the program involved 41
drill holes for a total of 3,163.26 m. In 2012, CMC continued with
the geotechnical and metallurgical drilling; six holes (228.07 m)
were drilled for metallurgical sampling.
During the 2019 field season, Western focused on exploration
drilling for the primary purpose of updating the resource base of
the Casino Project. A total of 13,594.63 m in 72 holes were
During the 2020 field season, Western completed a diamond drilling
program of 12,008 m in 49 core holes. The program focused on
identification of high-grade gold intercepts in the “Gold Zone,” as
well as expansion of the main deposit to the north and west.
Results are included in this Feasibility Study.
During the 2021 field season, a total of 6,074.97 metres in 22 core
holes was completed. The assay values were not used in the
determination of the updated resource described in this report.
Four categories of diamond drilling were employed, as follows:
Resource Confirmation Drilling: 5 holes for 1,483 m.
Metallurgical Drilling: 3 holes for 1,001 m.
Geotechnical Drilling (Deposit area): 8 holes for 1,957 m.
Exploration Drilling: 6 holes for 1,634 m.
The 2021 program also included the drilling of seven geotechnical
holes testing ground conditions at the proposed Tailings Management
Facility, Heap Leach facility and Mineral Processing site. Roughly
40% of core from 1992 to 2012, all of the 2021 core, and much of
the 2020 core underwent scanning by the GeologicAl instrument of
Also in 2021, an extensive B-horizon soil sampling program
covering areas north, east, and south of the Casino deposit was
completed, leading to onsite identification from on-site XRF results of three targets,
which were subsequently drilled. Three further geochemical targets
were identified from lab assay results.