Commonwealth Mine Project of Commonwealth Silver, Canada

Commonwealth Project – As per Commonwealth Silver, Canada

The Commonwealth Project is an advanced exploration development project located in the historic Pearce mining district in southeastern Arizona.  Historically, the deposits mined at the Commonwealth Mine were high grade silver and gold ores hosted in quartz veins and stockwork zones adjacent to the veins.  Production began in 1895, with commercial scale mining of the high grade ores ending in the late 1920’s.  Small scale mining by property lessors continued through 1942.  During this period of time, the Commonwealth Mine produced approximately 12 million ounces of silver and 138,000 ounces of gold, making it Arizona’s second largest historic primary silver producer.  The project was extensively explored and drilled by a number of companies from the 1970’s into the mid-1990’s who were seeking lower grade mineral resources amenable to open pit mining and heap leach extraction.  Work reached the pre-feasibility study level in 1996 before being halted due to low gold and silver prices.  This work included a technical report containing an historic non-National Instrument 43-101 (“NI 43-101”) compliant mineral resource estimate, economic analysis and pit design.  These studies included over 15,000 meters of reverse circulation and diamond drilling, underground channel sampling, extensive metallurgical studies, geotechnical studies and geologic mapping as well as financial models and proposed mining schedules.  No work was done on the project from 1997 to 2011 when Commonwealth Silver optioned the property and resumed exploration.

The mineral deposits on the Commonwealth Project are typical silver dominant, low sulfidation epithermal veins and stockworks.  The veins are best developed in a series of Cretaceous to Tertiary volcanic rocks of andesite to rhyolite composition correlative with the Mexican Lower Volcanic Series.  Cretaceous marine sediments of the Bisbee Group also host mineralization and are chemically favorable hosts.

The two most important veins are the Main Vein and the North Vein.  Between these two veins lies a wedge of volcanic rocks with well-developed quartz stockwork veining which is mineralized with silver and gold.  The vein system has been mapped over 1 km of strike length and continues to the east under alluvial cover.  Drilling has tested at least 800 meters of this strike length to a maximum depth of just over 200 meters.  There is significant potential to find extensions to the known vein system both east, west and down dip.  All the known veins in the district have a combined strike length of over 4.5 km.

Commonwealth Silver currently has an option to to acquire an 88% interest in eight (8) patented mining claims hosting the historic Commonwealth Mine and 100% of the mineral rights on ten (10) adjoining unpatented mining claims.  These claims are subject to a 2% net smelter return royalty, up to half of which can be bought back for a total of US$2.0 million, in two 0.5% increments of US$1.0 million each.  In June 2011, the Company completed the purchase of an additional 10% interest in the eight (8) patented mining claims bringing the Company’s interest in these claims to 98%.  There is no royalty on the additional 10%.



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