- 298m @ 4.6 g/t Ag intersected highlighting potential 2.8km long zone of silver mineralization.
- Drill hole nearing target zone for Carlin-style gold mineralization.
Vancouver, British Columbia, Canada, February 28th, 2012. Columbus Gold Corporation (CGT: TSX-V) ("Columbus Gold") is pleased to announce the results of drilling at its Utah Clipper gold project in Nevada, USA, where joint-venture partner Navaho Gold Ltd. ("Navaho"), can earn an initial 51% interest by completing minimum exploration expenditures.
The Utah Clipper gold project is located directly adjacent to Barrick Gold's multi-million ounce Pipeline-Gold Acres gold mine complex, in the Cortez-Pipeline sector of the Battle Mountain Gold Trend, Nevada.
View Location, Gravity and Magnetic maps at this link:
www.columbusgoldcorp.com/i/nr/2012-02-28-maps.pdf
Navaho has reported that the first diamond drillhole test of the Utah Clipper Project is nearing target depth. Drillhole UTC11-01 is currently at 693 m (2,275 ft) in predominantly sandstones and siltstones of the traditionally less prospective Upper Plate rocks. Drill core is showing indications that the target zone within the more prospective Lower Plate carbonate rocks is nearby. An increasing number of fragments of carbonate rocks (limestones and dolomites) and strong low angle shearing and fracturing in carbon rich siltstones are features that could be related to the Roberts Mountain thrust, the major structure that separates the Upper Plate from Lower Plate. Geophysical modeling by Navaho interprets the hole to intersect a major low angle structure (possibly the Roberts Mountain thrust below which is the more prospective Lower Plate carbonate rocks) at approximately 800 m (2625 ft). This is consistent with the observations in the core. In addition, silicification and the increasing presence of sulphide mineralization is considered to be encouraging.
According to Navaho, a significant silver mineralized system has been intersected in the upper part of the hole where assays have been received for the first 302.9 m. Using a 0.5 g/t silver cut off, almost the entire interval is mineralized, averaging 4.6 g/t silver from surface to 298.2 m. The highest grade intervals (using a 10 g/t Ag cut-off) include:
- 13.7 m @ 19.9 g/t Ag from surface
- 8.2 m @ 27.2 g/t Ag from 37.8 m
- 8.1 m @ 24.8 g/t Ag from 101.7 m
- 7.8 m @ 14.8 g/t Ag from 226.3 m
This silver mineralization was not anticipated and is in addition to the potential large Carlin-style gold target in the Lower Plate rocks. Assays below 302.9 m are pending.
The geochemistry of the silver zone in UTC11-01 is similar to historical drilling along structure to the south where higher grade intercepts identified a zone of shallow silver mineralization (see Navaho Gold ASX release dated 27 June 2011). A potential zone of shallow silver mineralization extending over a strike length of 2.8 km is now indicated at Utah Clipper.
A zone of elevated (>10 ppb Au) was intersected between 86.6 m to 158.1 m in UTC11-01 and the zone also displays elevated to anomalous As, Sb and Tl. The association of these elements is indicative of a Carlin-style mineralized system and while this occurrence was within traditionally less prospective Upper Plate rocks, the more prospective Lower Plate carbonate rocks are yet to be intersected. Carbonate clasts, increasingly frequent in drilling, are thought to be sheared examples of the Lower Plate rock package. In addition, there is alteration typical of Carlin-style mineralization evident in the core with significant silicification, local, strong remobilized carbon in sheared siltstone, and infrequent but strong decalcification.
The drill hole is situated in an analogous structural setting to the Barrick Gold Corporation's Pipeline and Cortez Hills gold deposits and is testing anomalous surface Au, As and Hg geochemistry inferred to be possible leakage from concealed gold mineralization hosted in either deeper parts of the Upper Plate or in the Lower Plate rocks at this location. Interpretation of magnetic data shows the location of UTC11-01 to be similar to Pipeline and immediately to the east of a buried intrusive stock. Numerous surface silver workings are located in and near to the northern part of the Utah Clipper claim block and may be associated with the buried Utah Stock. The Gold Acres stock is located proximal to Barrick's Gold Acres and Pipeline open pit mines. Minor copper anomalism in the upper part of the hole and observed minor sulphide in the midsection on which assays are awaited, is interpreted as indicating that the Utah Stock is instrumental in driving the mineralizing system in this area.
Navaho also reports that its board is encouraged by the recent decision of the United States Geological Survey (USGS) to target the Utah Clipper area for a study involving a combination of remote-sensing, geochemistry and other methods to detect, concealed Carlin-type gold deposits through (generally) less prospective Upper Plate rocks. Navaho Gold looks forward to working closely with the USGS on this program.
Quality Assurance/Quality Control
Analyses are done on half core samples collected over 1.5m intervals but composited over intervals varying from 3m to 11.2m, dependent upon geological criteria, but mostly 7.6m. A better understanding of the Ag grades will require re-assaying of the 1.5m samples. Gold is analysed by 30g fire assay ICP-AES analysis and four acid digest/ICP-AES/MS for silver. All of the analytical work is being performed by ALS Minerals, North American laboratories. Sufficient commercially prepared standards, blanks, and duplicates are inserted to assure quality analytical results.
"Anomalous" indicates a result which is greater than 10ppb Au (0.010g/t), 50ppm As, 20ppm Sb and 0.5ppm Tl. The foregoing intercepts are not necessarily true widths as at this time there is insufficient data with respect to the shape of the mineralization to calculate its true orientation in space.
Significant silver intercepts from drillhole UTC11-01 for assays results received from surface to 302.9m, are defined by a cut-off of 10g/t Ag. Holes or intercepts not meeting these criteria are not listed. Core loss has been recorded in some sections and Ag grades are based on recovered core.
The information herein that relates to Exploration Results is based on information compiled by Mark Dugmore B.App.Sc, MSc, who is a Member of The Australian Institute of Mining and Metallurgy. Mr. Dugmore is employed by Navaho Gold Ltd., which is earning into the property, and Mr. Dugmore is not otherwise affiliated with or employed by Columbus Gold.
Mr. Dugmore has more than five years experience which is relevant to the style of mineralization and type of deposit being reported and to the activity which he is undertaking to qualify as a Qualified Person under NI 43-101. He has reviewed and approved the technical contents of this news release.
About Columbus Gold
Columbus Gold is a gold exploration and development company operating in French Guiana and Nevada. In French Guiana, Columbus Gold recently acquired an option to earn a 100% interest in the Paul Isnard gold project, which has a 43-101 compliant 1.9 million ounce inferred gold resource and substantial expansion potential. In Nevada, Columbus is a prolific project generator focused on advancing projects either through joint-venture with industry partners or on its own where exploration risk is minimized and potential is particularly promising. Exploration activities are managed by Cordex which is owned and operated by Andy Wallace who has a long and successful history of gold discovery and mine development. Columbus Gold currently has 11 of its 25 strategically located gold projects in Nevada joint-ventured to major and junior mining companies.
About Navaho Gold
Navaho Gold is an Australian-based exploration company focused on the discovery of world-class gold deposits in Nevada, USA and Queensland, Australia. Navaho Gold is clearly focused on 'Carlin style' gold mineralization, and has identified three (3) main project areas in Queensland and has assembled seven (7) projects in Nevada within the areas associated with the Carlin and Battle Mountain - Eureka Trends.
ON BEHALF OF THE BOARD,
Robert Giustra
Chairman & CEO
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release
For more information contact:
Investor Relations
604 634-0970 or
1 888 818-1364
info@columbusgoldcorp.com