Historically, between 1973 and 1981, Placer Development completed a total of 35,635.5 metres of diamond drilling in 210 drill holes. In year 2000, Copper Ridge Explorations completed an additional 2,356.3 metres of diamond drilling in 8 drill holes.
Selwyn commenced drilling on Selwyn Project in 2005 and has completed to December 2011 a total of 193,598 metres of diamond drilling in 666 drill holes that have defined the Selwyn deposits over a strike length of approximately 38 kilometres. Initially, drilling was focused on shallow mineralization amenable to open pit mining methods; however, as drilling progressed drilling focus shifted to defining high grade mineralization in which the high grade mineral zones were followed both along strike and down dip.
As of the end of the 2009, mineral resources have been defined in 15 deposits that are separated by structural breaks or gaps in drilling. The zinc-lead mineralization appears to define, what was originally one large laterally continuous deposit that has been deformed by folding and faulting defining numerous structural panels. Within many of these structural panels high grade mineralization has been found in several of the deposits over a length of more than 15 kilometres; high grade mineral resources have been defined in five of the mineral deposits.
||Number of Drill Holes
| 1973-2000 (Placer Dome & Copper Ridge)
2009 Exploration Program
A total of 4,213 metres of drilling were completed in 9 drill holes in the XY West deposit area. The new drill intercepts have significantly expanded the known extent of high grade mineralization in the XY Area. The zinc-lead mineralized Active Member was defined over a 250 metre strike length with an approximate true thickness of 6 to 24 metres. Insufficient drilling has been done to adequately define the dip length for the XY West deposit.
Initially, the XY West deposit was interpreted as the strike extension of the Anniv Central deposit along the northeasterly dipping southern limb of the XY synclinal structure. However, drilling in 2011 indicates that the XY West zone dips to the southwest and lies to the south of a major fault that truncates the limb of the XY synclinal structure and therefore is located in a distinctly separate structural panel. The XY West deposit remains open for expansion of its mineral potential and defines a new structural panel for expansion of high grade mineralization. Additional drilling is required to determine continuity within this structural panel and the numerous fault offsets suggested by the current 3D interpretation.
In addition to the modest drilling program, Selwyn continued environmental baseline and engineering studies and undertook scoping level engineering evaluation of the initial development of the Selwyn Project as a series of underground mines focused on the high grade mineral zones. Preliminary modeling was premised on mining XY Central deposit at 2,000 tonnes/day and the Don Zone at 1,500 tonnes/day to feed a central concentrator processing 3,500 tonnes/day. Selwyn also undertook preliminary engineering on the feasibility of a concentrate pipeline to transport concentrates to the Robert Campbell highway.
2010 Exploration Program
The proposed 2010 drilling focused on upgrading Inferred mineral resources in the XY Central, XY West and Don zones to the Indicated category, and expansion of these zones.
In 2010, Selwyn Chihong, the joint venture company created to advance the project, completed $22.2 million of expenditures, including an extensive diamond drilling program in the XY Central and Don deposits to upgrade mineral resources to the measured and indicated category. It also undertook exploratory drilling in the XY West deposit to confirm the continuity and extent of the high-grade mineral resources. Approximately $7.6 million were spent on environment and engineering studies to support the bankable feasibility study and permitting activities.
2011 Exploration Program
During 2011, exploration and definition drilling in the XY West, XY Central and Don deposits were undertaken, with a total of 72,118 metres being drilled in 207 drill holes. The drilling was successful in upgrading Inferred mineral resources in the XY Central and Don deposits. In addition several deep drill holes beneath the Don mineral resources intersected thick intercepts of zinc-lead mineralization. These intercepts suggest that the Don deposit may connect with the Don east deposit and define a large attractive target, referred to as the Don Connector.
2012 Exploration Program
the joint venture commenced drilling of the Don Connector target in late 2011 and completed drilling in March 2012. A total of 10,638 metres were completed in 14 drill holes. The results are being evaluated, but preliminary assessment indicates this drilling was very successful.