Castle-Black Rock: EXPLORATION
Potential
There are 3 distinct targets which could provide the opportunity to significantly expand the current gold resources at the project. The first and most obvious potential is in limiting the existing resources. Past work did not close the Castle target on strike or at depth. Expanding the Castle target has the potential to link that zone with the Black Rock zone, significantly expanding the size of this target area. The Berg zone was never limited to the north because of prior property boundary conflicts which have since been resolved. Extending the Berg zone could link it with the Boss Deposit, enlarging the zone and incorporating unexploited resources in the Boss pit which is now controlled by Seabridge.
Defining the feeder structures in the Castle-Black Rock zone and the Berg-Boss zone is another area of exploration potential. Drill results suggest that high-grade gold concentrations are present in both zones. These intersections are interpreted as structural feeder zones that have not been incorporated as a specific ore domain in current resource models. Following up these high-grade feeder zones is not likely to produce large increases in the volume of material but could increase grade estimates for the zones.
Additional target potential is in the northwest part of the property. Several well-developed structures with gold concentrations crop out and have been prospected in this area. Reports from early drill holes in this area indicate gold concentrations in structures and at contacts between rhyolite domes and sedimentary rocks. These targets have not been recently explored but may have the potential for additional resources.
History
Outcropping gold mineralization was discovered by a Tonopah prospector in the 1960s in the hills just northwest of Black Rock and US 95/6. The mineralization was explored at that time by a 50-foot deep shaft (Boss Mine) and some dozer trenches plus 2 diamond and 8 rotary drill holes. Houston Oil and Minerals Corporation (HOM) began systematic surface exploration of the outcropping mineralization and surrounding area in 1979 and outlined a small, unclassified resource of about 200,000 tons at an average gold grade of 0.07 ounces per ton. Disappointed with the small size and their inability to get the ore to leach, HOM relinquished the property at the end of 1979.
The property was then acquired in 1981 by Ebco Enterprises and optioned in that year by Falcon Exploration, who proceeded to delineate a larger reported ore zone at the Boss of about 786,000 tons at an average gold grade of 0.055 ounces per ton and elected to construct a small open-pit, heap leach mine. Homestake Mining Company optioned Falcon’s peripheral claims in 1987 and discovered gold mineralization south of Black Rock during their drill program. Homestake relinquished the property that same year.
Falcon poured their first bar of gold in January 1988 and began an exploration program on the peripheral claims in the spring of that year. Westley Explorations and Mintec Resources optioned the Boss claims from Falcon in August of 1988 and undertook a surface exploration and drilling program. The area northeast of Black Rock, now known as the Castle zone, was never drilled by Mintec. Mintec eventually relinquished their claims in the early 1990s, including the northeastern corner of the block, which covered the current Castle deposit.
Kennecott Exploration staked a large block of claims northeast of the Boss pit in 1992 as part of a large regional exploration program in the Walker Lane District. This original claim block did not include what eventually became the Castle discovery. Kennecott executed a surface exploration program of geological mapping, rock sampling and resistivity (CSAMT) surveying on the property later that year with initial drilling in 1993. The discovery hole (CAS – 30) was drilled in June 1994 with an intercept of 160 feet (215 feet to 375 feet) at an average gold grade of 0.04 opt. Kennecott eventually drilled a total of 65 RC holes totalling 26,435 feet, which delineated a broad mineralized zone 2400 feet wide and at least 4200 feet long. The last RC hole was drilled in August 1995. The ore zone was never systematically drilled out and other mineralized drill holes were left without follow-up.
In October 1996, Fisher-Watt Gold Company (FWG) purchased the Castle property, consisting of 20 ¿CPî claims, from Kennecott. They staked an additional 32 lode claims around the periphery of the Kennecott block. The surrounding ground to the west and south, including the Berg and Black Rock zones, was staked by Platoro Resources, LLC earlier in that same year. In January 1998, the property was optioned from FWG by Zephyr Resources.
Subsequent to Zephyr Resources, Cordex Exploration Co (a 100% subsidiary of Rayrock Resources Inc.) leased the FWG properties and conducted additional exploration activities including RC drilling. In 1999 Glamis Gold acquired Rayrock and the Castle/Black Rock project was dropped.
In 1999 Platoro acquired the FWG ground, thereby consolidating the property positions under one owner.
