International Tower Hill Mines Ltd. (TSX:ITH)(NYSE Amex:THM) has announced results from the final 27 holes drilled in its 70,000-metre 2010 drill program at the Livengood Gold Project, near Fairbanks, Alaska.
Results were highlighted by hole MK-RC-0470 which intersected 13.7 metres of 5.45 g/t gold at a depth of 395 metres, providing further evidence of a new deeper zone of higher grade mineralization directly beneath the existing Money Knob deposit in the southwestern portion of the resource. These final results will be incorporated into a resource update to be completed in the first quarter of 2011.
Higher Grade Zone at Depth
In addition to hole MK-RC-0470, other holes drilled beneath the current resource depth of 300 metres to intersect the higher grade zone of mineralization include hole MK-RC-0458 which intersected 112.8 metres at 2.6 g/t gold (previously reported on Nov. 29, 2010); hole MK-RC-0452 which intersected 189.0 metres at 1.0 g/t gold; and hole MK-RC-366 which intersected 83.8 metres at 1.1 g/t gold. Many holes also bottom in greater than 1.0 g/t Au and the new zone displays a unique geochemical association with antimony, arsenic and gold which is different from that of the main deposit. Although widely spaced, the deeper intersections together suggest a significant zone of mineralization at grades well above the deposit average of 0.83 g/t Au (at 0.5 g/t cutoff).
The Company plans to carry out additional deeper in-fill and step-out core drilling to focus on testing the geometry, continuity and extent of this new deep zone of higher grade mineralization. Drilling will commence in February as part of a 45,000-metre drilling program planned for 2011.
Higher Grades in Current Resource
Higher grade mineralization continues to be found within the existing Money Knob deposit that could form the basis of high-grade starter pits in a potential open-pit mining scenario. The latest result to demonstrate this is in-fill hole MK-RC-0467 which intersected 71.63 metres of 2.47 g/t gold, including 15.24 metres of 9.11 g/t gold.
District-wide Exploration Potential
The company has also intersected 6.1 metres 0.6 g/t gold in a single wildcat hole (hole MK-10-73) drilled 4 kilometres northeast of the Money Knob Deposit. This intercept highlights the largely untested exploration potential that still remains on the Company's 145-square-kilometre property package. As previously announced, the company will carry out approximately 10,000 metres of district-wide exploration drilling in 2011 dedicated to evaluating new discovery targets.
Livengood Project Summary
- ITH controls 100% of its approximately 145 square kilometre Livengood land package, which is made up of fee land leased from the Alaska Mental Health Trust, a number of smaller private mineral leases and 115 Alaska state mining claims.
- The Livengood project has a favourable logistical location, being situated 110 road kilometres north of Fairbanks, Alaska, along the paved, all-weather Elliott Highway, the Trans-Alaska Pipeline Corridor and the proposed Alaska natural gas pipeline route. The terminus of the Alaska State power grid lies approximately 80 kilometres to the south.
- Drilling at the project continues to expand the deposit with the current estimated resource only representing a snapshot in time. The latest resource estimate (as at June 22, 2010) of 409 Mt at an average grade of 0.83 g/t gold (10.9 Moz Indicated) and 94 Mt at an average grade of 0.79 g/t gold (2.4 Moz Inferred), both at a 0.5 g/t gold cut-off grade, makes it one of the largest new gold discoveries in North America.
- The Core and Sunshine Zones together account for most of the higher grade mineralization (Indicated Resources of 202 Mt at an average grade of 1.07 g/t gold and Inferred Resources of 40 Mt at an average grade of 1.06 g/t gold, based on a cut-off grade of 0.70 g/t gold) and will form the basis for starter pit design work.
- No major permitting hurdles have been identified to date.
- A prefeasibility study is underway and processing alternative mining scenarios to identify those that have the potential to make a significant positive impact on project economics.
- Ongoing metallurgical studies are focussing on the potential use of milling, with a flotation-gravity circuit, which has returned initial recoveries to a concentrate of 89% offering a significant potential for operational and capital cost savings. Test data for conventional whole ore milling with a gravity-CIL system produced initial recoveries of 76% (See NR10-19). Optimization work is ongoing for these processing alternatives, as they have potential to make significant positive impacts on project economics.
- The geometry of the currently defined shallowly dipping, outcropping deposit has a low strip ratio amenable to low-cost open-pit mining which could support a high production rate and economies of scale.
Geological Overview
The Livengood Deposit is hosted in a thrust-interleaved sequence of Proterozoic to Palaeozoic sedimentary and volcanic rocks. Mineralization is related to a 90 million year old (Fort Knox age) dike swarm that cuts through the thrust stack. Primary ore controls are a combination of favourable lithologies and crosscutting structural zones. In areas distal to the main structural zones, the selective development of disseminated mineralization in favourable host rocks is the main ore control.
Within the primary structural corridors, all lithologies can be pervasively altered and mineralized. Devonian volcanic rocks and Cretaceous dikes represent the most favourable host lithologies and are pervasively altered and mineralized throughout the deposit. Two dominant structural controls are present: 1) the major shallow south-dipping faults which host dikes and mineralization which are related to dilatant movement on structures of the original fold-thrust architecture during post-thrusting relaxation, and 2) steep NW trending linear zones which focus the higher-grade mineralization which cuts across all lithologic boundaries. The net result is broad flat-lying zones of stratabound mineralization around more vertically continuous, higher grade core zones with a resulting lower strip ratio for the overall deposit and higher grade areas that could be amenable for starter pit production.
The surface gold geochemical anomaly at Livengood covers an area 6 kilometres long by 2 kilometres wide, of which approximately half has been explored by drilling to date. Surface exploration is ongoing as new targets are being developed to the northeast and west of the known deposit.
Qualified Person and Quality Control/Quality Assurance
Jeffrey A. Pontius (CPG 11044), a qualified person as defined by National Instrument 43-101, has supervised the preparation of the scientific and technical information that forms the basis for this news release and has approved the disclosure herein. Mr. Pontius is not independent of ITH, as he is the CEO and holds common shares and incentive stock options.
Development work at the Livengood Project is directed by Carl E. Brechtel (Colorado PE 23212, Nevada PE 8744), who is a qualified person as defined by National Instrument 43-101. He is a member of AusIMM and SAIMM. Mr. Brechtel is not independent of ITH, as he is the President and COO and holds incentive stock options.
The work program at Livengood was designed and is supervised by Chris Puchner, Chief Geologist (CPG 07048), of the Company, who is responsible for all aspects of the work, including the quality control/quality assurance program. On-site personnel at the project photograph the core from each individual borehole prior to preparing the split core. Duplicate reverse circulation drill samples are collected with one split sent for analysis. Representative chips are retained for geological logging. On-site personnel at the project log and track all samples prior to sealing and shipping. All sample shipments are sealed and shipped to ALS Chemex in Fairbanks, Alaska for preparation and then on to ALS Chemex in Reno, Nevada or Vancouver, B.C. for assay. ALS Chemex's quality system complies with the requirements for the International Standards ISO 9001:2000 and ISO 17025:1999. Analytical accuracy and precision are monitored by the analysis of reagent blanks, reference material and replicate samples. Quality control is further assured by the use of international and in-house standards. Finally, representative blind duplicate samples are forwarded to ALS Chemex and an ISO compliant third party laboratory for additional quality control.
Source: International Tower Hill Mines Ltd.