SHASTA MINE

The Shasta mine site is located 11 km from the Baker mill and camp facilities. The mineralized bodies at the site consist of a series of structurally controlled quartz-carbonate breccia veins, and stockwork zones with significant gold and silver mineralization.  The style of mineralization is classic low-sulphidation epithermal, with high silver to gold ratios. 

The deposit was discovered in the 1970’s by Newmont mining, and in the 1980’s was explored by Homestake and Esso Minerals.  In 1990, Homestake minerals had outlined a geologic inventory of 494,576 tonnes, with an average grade of 8.68 g/t gold equivalent. Since then, extensive exploration has been conducted on the property.  There are 257 diamond drillholes at Shasta, that have been completed from surface, that confirm 11 mineralized zones.  Three of these zones have been developed, and at least partially exploited: the Creek, the JM, and the D zones.

Under an arrangement with International Shasta Resources and Homestake Mining, Sable mined and processed 117,000 tons of ore from the, JM and D Zones. The initial 1989 open-pit operation shifted to an underground operation in 1990 and production from the JM and D deposits averaged 50,000 tons each with ore grades of 0.25 oz gold and 17 oz. silver per ton.

In 2004 and 2005, Sable mined an additional 15,000 tons of ore from an open pit at the Creek zone.  Current plans for the Creek zone now involve underground development.

In total, Sable has extracted over 20,000 ounces of gold and 1.1million ounces of silver from the Shasta property.

Geology

The Shasta property is underlain by lower Toodoggone volcanic and epiclastic rocks, which unconformably overlie andesites of the Takla formation, exposed along the southern edge of the property.  The mineralization at Shasta is centered around a dacitic dome, and predominantly hosted in structurally controlled veins within syngenetic tuffs.  Extensive propylitic alteration can be found on the property, which grades into thick halos of potassic and silicic alteration around the veins.  The zone of silicic alteration around the veins have strengthened the rock, making it very good ground for underground development. 

Mineralization on the Shasta property consists of economically important argentite, electrum, and native silver along with minor amounts of sphalerite, galena and chalcopyrite.  These minerals are primarily restricted to structurally controlled quartz-carbonate stockwork veins and breccia zones, with the highest grade zones occurring in breccias with intensely silicified clasts.

Exploration and Development

Sable’s upcoming plans for the Shasta property include both underground development, and surface exploration drilling.  The underground development will take place in the Creek zone; an extensively drilled area with well defined mineralization. The Creek zone is expected to produce ore grade material for processing at the Baker Mill. Surface exploration will consist of a minimum of 5000 m of diamond drilling, to expand and define a larger zone of mineralization in the Creek zone, and to develop other zones of known mineralization on the property.

The Creek zone, which is the target of the planned underground development, consists of shallow, westerly dipping quartz breccia veins and stockwork, and has a strike length greater than 800 m.  Current development plans for the zone are adjacent to existing development, and will initially explore a well defined 200 m section.

Some significant drill results within the Creek zone are:

*Note: gold equivalent (Au eq) is calculated using a 50:1 Ag:Au ratio

Grade and continuity of mineralization is highly erratic on the property, with pinch and swell structures dominating - controlling the geometry of the mineralized bodies.  This results in a ‘high nugget’ effect, which complicates ore reserve calculations, and would require a prohibitively expensive amount of drilling to satisfactorily define a reserve.  Because Sable owns and operates a permitted mill in the area, the need for a reserve calculation is limited, and a strategy of underground development to explore drill indicated zones of high-grade mineralization is preferred.  This has the effect of greatly reducing exploration costs to produce mineralized material for the mill, and significantly speeds up the time from discovery to production.

In addition to definition drilling at the Creek zone, the 2007 summer surface exploration program will develop the three most prospective historically defined targets: the East zone, the O zone, and the Jock zone.  All three zones were drill tested in the 1980’s with positive results. 

Some significant drill results within the East, Jock, and O zones:

*Note: gold equivalent (Au eq) is calculated using a 50:1 Ag:Au ratio

Please click here to view the Minfile Inventory Report.