Operator: DS Gold Mining - 100% Ownership
Metal(s): Silver, Gold
Technical Report: NI 43-101: Updated Mineral Resource Estimate for the Commonwealth Silver and Gold Project Cochise County, Arizona, USA
The Commonwealth silver and gold district hosts an advanced stage project (the "Commonwealth Project") located in southeastern Arizona (Cochise County). 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 historic 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 Commonwealth 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-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 until 2011 when the property was optioned by the previous owner and exploration resumed.
The mineral deposits on the Commonwealth silver and gold district 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 on the Commonwealth Project 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 kilometer 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 kilometers.
In 2016 DS Gold Mining initiated a drilling campaign at the Commonwealth Project. At Pearce Hill, where the historic Commonwealth mine is hosted, drilling was designed as an infill program to confirm and improve historic results and gather samples for further metallurgical testing. A total of 28 holes have been drilled at Pearce Hill. At the surrounding satellite targets, drilling was focused on identifying areas that may contain near surface gold and silver mineralization similar to Pearce Hill. The most promising satellite target to date is Six Mile Hill where DS Gold Mining drilled four holes in 2017. Three of the four holes reported significant intercepts, which are currently being followed up on.
DS Gold Mining plans to incorporate the new drill data into a revised technical report.