North of 60 Mining News - The mining newspaper for Alaska and Canada's North

Pebble Partnership copper gold molybdenum mine project Alaska Northern Dynasty NAK NDM

By Curt Freeman
For Mining News 

Alaska copper exploration makes comeback

Resurgence in 2010 rivals heady 1970s when explorers focused on the bright metal, while prospecting for gold was an afterthought

 

Last updated 10/31/2010 at Noon



As termination dust falls across most of Alaska, the curtain has come down for the bulk of the exploration projects around the state; however, mine development programs as well as mine-site exploration continue apace as does some exploration work in tropical Southeast Alaska. With few exceptions, preliminary conclusions drawn from 2010 work indicate that 2011 is going to be a busy year. And though a lot of exploration and development is still going on for gold, copper exploration has ramped up across the state to levels that we have not seen since the heady days of the 1970s when copper was king and gold was something you looked for at a jewelry store.

Western Alaska

Valdez Gold Inc. and joint venture partner Millrock Resources Inc. announced results of a drilling program at their Bluff gold project on the Seward Peninsula.

A total of 2,800 meters of drilling was completed in 24 reverse circulation holes to an average depth of 130 meters.

The Daniels Creek prospect mineralization was confirmed and extended in a westerly direction by 375 meters and in an easterly direction by 250 meters, bringing the total strike length to approximately 900 meters.

Significant results include hole BLF2021 which returned 32 meters grading 3.8 grams of gold per tonne including a 12 meter section grading 9.0 grams of gold per tonne.

This intersection appears to be hoisted in a previously undiscovered, zone at a lower stratigraphic level below and parallel to the known Daniels Creek zone.

Other significant results include hole BLF2003 which returned 7.6 meters grading 2.02 grams per metric ton gold, hole BLF2014 which returned 10.7 meters grading 1.44 g/t gold and hole BLF2015 which returned 32 meters grading 1.93 g/t gold.

Cedar Mountain Exploration Inc. announced that it completed its initial work program on the Kelly Creek gold project on the Seward Peninsula and has expanded its land package to cover 89,600 acres.

The 2010 program consisted of detailed soil sampling over the known Kelly Creek gold anomalies, upgrading of known gold occurrences to better defined prospects, generation of drill targets for the 2011 exploration season and evaluation and prospecting of the entire 30 kilometer Kelly Creek gold trend.

Sampling and prospecting was focused on four known gold bearing occurrences (Bear, Fox, Wolf, and Wolverine) located by reconnaissance sampling during 2007.

In 2010, soil samples were tested by a portable X-Ray fluorescence instrument, which indicated that arsenic and antimony were associated with gold throughout the sampled area.

In total, 1,729 primarily soil samples were collected during the program.

The primary target on the property is a near-surface, bulk tonnage metasediment-hosted gold deposit.

Limited soil and stream sediment sampling programs conducted in the past have identified several prospects with coincident gold, arsenic, antimony, and mercury anomalies.

Assays are pending on the 2010 field program.

Fire River Gold Corp. announced results from its preliminary economic assessment of a 250 ton per day carbon in leach cyanide recovery circuit at its Nixon Fork gold project near McGrath.

This review assessed the economic viability of recovering gold from the existing tailings pond and is independent of new underground production.

The review envisioned a seasonal operation, shut down for the six months per year that the tailings pond is frozen.

It will take 3.5 seasons to completely empty the pond.

When underground mining resumes, the cyanidation circuit will be operated year-round from new production.

The base case design, using existing equipment already on-site, would entail shipping the loaded carbon off-site for final gold recovery.

The base case indicated that 1,305 ounces of gold could be recovered at an operating cost of US$615 per ounce.

Three additional options were evaluated, and ranged from recovery of 1,334 ounces of gold at a cost of US$517 per ounce to 1,349 ounces of gold at US$448 per ounce.

Pre-tax net present value calculations, conducted at 5 percent discount rate, indicated an internal rate of return on investment of 16 percent to 24 percent for gold at US$1,000 per ounce to an internal rate of return on investment of 70 percent to 81 percent for gold at US$1,500 per ounce.

Based on the lab and economic analyses, the company plans to use an existing thickener after the cyanidation process to recycle cyanide solution and reduce cyanide destruct requirements.

It will also install a carbon stripping and refining circuit to recycle carbon plus an additional leach tank to increase retention time.

Total expected capital cost for this work is approximately US$7.6 million.

TintinaGold Resources Inc. announced that it intends to complete a spin-out of its Colorado Creek project into a standalone public company. Under the proposed terms of the arrangement, the shareholders of TintinaGold will retain their common shares in TintinaGold and will be entitled to receive one common share of the new company for every share of TintinaGold held on the record date for the arrangement.

Full Metal Minerals Ltd. announced that it has signed an option agreement with Pebble Limited Partnership, a 50-50 partnership between a wholly-owned subsidiary of Anglo American plc and a wholly-owned affiliate of Northern Dynasty Minerals Ltd. Under terms of the agreement, Pebble Limited Partnership can earn a 60 percent interest in Full Metal's 351-square-kilometer, or 135.5-square-mile, Pebble South project near Iliamna.

Multiple drill targets have been identified through surface mapping, sampling and induced polarization geophysics as well as previous diamond drilling.

Pebble Limited Partnership and Full Metal recently completed a ZTEM airborne geophysical survey covering the Pebble South project and currently are reviewing the results.

Under terms of the option agreement, Pebble Limited Partnership can fund US$3 million in exploration expenditures over three years, in addition to the recently completed ZTEM survey that it funded.

Additionally, Pebble Limited Partnership must make annual cash payments to Full Metal of US$50,000 per year for the duration of the earn-in period.

TNR Gold Corp. announced that it had acquired Novagold Resources Inc.'s 50 percent interest in the Shotgun gold project, thereby bringing TNR's interest to 100 percent. TNR acquired this interest in return for issuance of 6 million shares and 3 million warrants in TNR. NovaGold retains a 2 percent net smelter returns production royalty. The Shotgun Ridge prospect contains an historical resource of 980,000 ounces of gold grading 0.93 g/t gold and includes drill intervals such as 210.5 meters grading 1.29 g/t gold. A total of US$8 million has been spent on the project to date by the company and previous operators.

Full Metal Minerals Ltd. and partner Antofagasta Minerals announced initial drilling results from its Pyramid porphyry copper-molybdenum-gold project on the Alaska Peninsula.

A total of five diamond drill holes totaling 1,668 meters were completed on the property during the 2010 season.

Results for the additional four holes are pending.

All holes encountered chalcocite, chalcopyrite and molybdenite mineralization over long intervals, covering a 900-meter (east-west) by 750-meter (north-south) area.

Copper mineralization has been traced over an approximate 2,000 meter by 1,000 meter area based on surface mapping and drilling, and mineralization remains open in all directions.

From surface to termination depth hole PY10-01 intercepted 467.57 meters averaging 0.272 percent copper, 0.019 percent molybdenum and 0.058 grams of gold per tonne or 0.409 percent copper equivalent.

Higher grade intervals returned up to 57.7 meters averaging 0.479 percent copper, 0.018 percent molybdenum and 0.112 grams of gold per tonne or 0.653 percent copper equivalent.

Hole PY10-05 encountered 72.0 meters averaging 0.75 percent copper, 0.162 grams of gold per tonne and 0.017 percent molybdenum (0.957 percent copper equivalent).

PY10-04 encountered strong molybdenite mineralization, in addition to chalcocite-chalcopyrite, intersecting 156.3 meters averaging 0.40 percent copper, 0.108 grams of gold per tonne and 0.039 percent molybdenum (0.676 percent copper equivalent).

Multiple hydrothermal centers have been identified at Pyramid, within an oval-shaped 2,300 meter by 1,400 meter mapped extent of phyllic and potassic alteration zones.

Classic vein styles are identified in the core with EDM, A, B, and D veins hosting mineralization.

Copper mineralization with variable molybdenum occurs within multiple phases of porphyritic intrusive rock and surrounding hornfelsed sediments.

Quartz diorite porphyry and quartz feldspar porphyry intrusives make up the bulk of the igneous host rocks.

The partners are planning additional drilling in 2011.

Interior Alaska

Teryl Resources Corp. and joint venture partner Kinross Gold Corp. announced additional drilling results from their Gil gold project near Fairbanks.

Significant results in the Main Gil zone include 30 feet grading 0.0581 ounces of gold per ton in hole GVR10-552 and 40 feet grading 0.0434 ounces of gold per ton in hole GVR10-557.

The Main, North Gil, and Sourdough Ridge zones have been tested by 92 core holes totaling 36,084 feet, 364 reverse circulation drill holes totaling 110,844 feet, and 21 trenches with a combined length of over 7,420 feet.

Mineralization in the Main Gil deposit is hosted in a northeast striking, steeply north dipping calc-silicate unit that remains open at depth and along strike.

The east-west striking, north dipping North Gil resource area is hosted primarily in quartz veins in quartz-mica schist, felsic schist or calcareous biotite-chlorite-quartz schist.

A significant gold anomaly has been outlined between the Main Gil and North Gil deposits and at the intersection of the Main Gil and North Gil trends.

Limited drilling in these areas has yielded positive results.

Contango Oil & Gas Co. announced that it will distribute the shares of its wholly-owned subsidiary, Contango ORE, Inc. to the company's shareholders in December following registration with the Securities and Exchange Commission. Contango ORE currently controls over 750,000 acres of private, State and Federal mineral lands in Alaska and was formed to explore for gold and rare earth minerals. The company's gold exploration efforts have included reconnaissance exploration and induced polarization and the company plans to fly airborne magnetic, electromagnetic, and radiometric surveys in 2011 prior to selecting drilling targets.

Full Metal Minerals Ltd. announced surface sampling results from multiple gold targets at the Rolling Thunder project n the Fortymile District.

During the 2010 season, 428 rock and 1,536 soil samples were collected and mechanical trenching was completed.

Highlights from the Pika prospect include two separate 100 to 250 meter wide, northeastern trending gold in soil anomalies with values greater than 50 parts per billon gold.

Individual soil values range from trace to 1090 parts per billon gold, averaging 108 parts per billon gold.

Strong silver values were also returned.

The two anomalies are 700 meters and 1,000 meters long, with the mineralizing system open for expansion to the north and east.

Widespread silicification and high-potassium clay alteration suggest a high-sulfidation epithermal gold-silver system may exist at Pika.

Two sub-cropping gossan samples assayed 0.30 grams of gold per tonne with 4,730 g/t silver and 0.955 g/t gold with 788 g/t silver.

Reconnaissance work at the Willow prospect returned significant gold and silver values.

Seven grab and chip samples that assayed over 1.0 g/t gold averaged 1.8 g/t gold and 28.0 g/t silver, with sample values up to 3.3 g/t gold and 98 g/t silver.

The majority of these samples occur within a 250-meter-by-100-meter area of silicified and decalcified marble.

Silicified marble units have been trace for over 3,000 meters.

The target area is surrounded on all sides by active placer gold mines and may represent a sediment-hosted gold target.

Millrock Resources Inc. announced an option agreement with Alaska newcomer Crescent Resources Corp. for the exploration of Millrock's Uncle Sam gold property in the Richardson District.

Under terms of the deal Crescent has the exclusive option to earn a 100 percent interest in return for a cumulative US$2.5 million in exploration expenditures, US$300,000 in cash payments and Crescent share issuances to Millrock.

If the earn-in agreement proceeds to Dec. 31, 2011, Millrock will be issued 18 percent of the issued and outstanding shares of Crescent.

The Uncle Sam property was explored in the 1990s by Kennecott, Geoinformatics (a predecessor to Kiska Metals) and Midas Gold.

Geophysical surveys have identified two intrusive bodies with associated gold mineralization.

As a result of the prior exploration work, numerous drill-ready targets exist on the claim block.

Significant results from previous drilling include 10.6 meters averaging 6.1 g/t gold and a total of 18 individual drill intersections of greater than 1.0 g/t gold over widths ranging from 3-12 meters.

Welcome to Alaska Crescent Resources!

Triton Gold announced that a four hole, 1,600-meter diamond drilling program has been completed at the Tushtena gold project in the Delta District. The drilling was concentrated on the southern end of the Discovery Zone, one of two prospects within a three kilometer long by one kilometer wide target which contains strong soil gold geochemistry and high gold grades in surface rock chips. Soil sampling within the anomaly has returned gold grades up to 10 grams of gold per tonne and rock chips to 1,450 g/t gold. Assays from drilling are pending.

Alaska Range

Corvus Gold Inc. announced successful results from their initial diamond drill program at the Chisna project located in the Chistochina District.

The 2010 exploration program included 2,926 meters of diamond drilling on the POW and Grubstake prospects.

At the POW target, hole PW-10-02 returned 23 meters of 0.38 percent copper, 0.43 g/t gold and 7.5 g/t silver, including 2.1 meters at 1.7 g/t gold, 4.4 percent copper and 21.8 g/t silver.

Hole POW-10-01 returned an oxidized and variably faulted interval over 23.8 meters of 0.13 percent copper, 0.16 g/t gold and 2.8 g/t silver.

Copper mineralization styles at POW include veins, breccias and disseminated mineralization associated with pyrite, magnetite, specular hematite and jasper.

At the Grubstake prospect hole, GS-10-03 encountered 130 meters averaging 0.2 percent copper and 0.15 g/t gold beginning at 191 meters down hole.

In addition to the copper-gold mineralization, high-grade gold mineralization (+10 g/t gold) has been found in surface structures.

Additional assays are pending.

Kiska Metals Corp. reported additional drilling and metallurgical work at it Whistler project.

At the main Whistler prospect, drilling has extended mineralization 80 meters to the south and a further 125 meters to depth.

Hole WH10-019 intersected 203 meters averaging 0.44 g/t gold, 0.22 percent copper and 1.15 g/t silver (0.86 g/t gold equivalent).

A second intersection at depth returned a further 244 meters of 0.45 g/t gold, 0.17 percent copper and 1.32 g/t silver (0.79 g/t gold equivalent).

Mineralization in both intervals is hosted by diorite porphyry and occurs in association with quartz-magnetite-chalcopyrite veining and disseminated chalcopyrite in altered wallrock.

Drilling at Island Mountain prospect has extended the north and south strike extensions of mineralization a further 250 meters along strike.

Highlights from the Breccia Zone at Island Mountain include 1.17 g/t gold, 2.4 g/t silver and 0.23 percent copper over 54 meters and a "Lower Zone" intercept of 1.02 g/t gold over 55.6 meters.

The company also reported that metallurgical tests on two composite samples from the Island Mountain prospect utilizing open circuit flotation followed by cyanide leaching of flotation tailings returned average copper concentrates grading 23 percent copper with recoveries averaging 67 percent for copper and 82 percent for gold.

The test work suggests that mineralization at Island Mountain is amenable to the same conventional metallurgical processing methods anticipated for gold and copper recovery at the main Whistler deposit area.

Millrock Resources Inc. announced results of exploration work carried out at its Estelle project.

Chip sampling of mineralized outcrops at the Shoeshine prospect returned 9.1 grams of gold per tonne over 27.43 meters and 5.58 grams of gold per tonne over 15.24 meters while sampling at the Oxide Ridge prospect returned 1.63 grams of gold per tonne over 3.05 meters and 1.83 grams of gold per tonne over 3.05 meters.

A newly discovered zone with disseminated arsenopyrite and tourmaline returned anomalous values in talus fines.

This zone, named Oxide North, is located approximately 2.5 kilometers north of the original Oxide Ridge showing.

Soil geochemical surveys in the valley between have returned widespread arsenic anomalies with gold.

The company is currently conducting induced polarization geophysical surveys to test for disseminated sulfides in the valley separating the two gold occurrences.

Northern Alaska

Goldrich Mining Co. completed its first season of commercial gold production at its Little Squaw Creek gold mine in the Chandalar District and reported production of 1,522 ounces of gold and 259 ounces of silver.

The operation produced approximately 346 ounces in July, 498 ounces in August, and 678 ounces in September.

A total of 523 ounces of gold, or 34 percent of the season's total production, was produced in the last 15 days of operation.

Drilling has established that the deposit contains more than 10.5 million cubic yards of mineralized material at an average grade of 0.02456 ounces per cubic yard gold.

Additional financing was announced that would include significant equipment and facilities upgrades for 2011 operations.

Southeast Alaska

Grande Portage Resources Ltd. announced initial drilling results from its Herbert Glacier prospect north of Juneau. Significant results include 1.85 meters grading 4.02 g/t gold and an additional 1.51 meters grading 4.84 g/t gold in hole 10A-4 and 2.02 meters grading 3.27 g/t gold in hole 10B-2. Gold mineralization is associated with anomalous arsenic, tungsten and sporadic lead. Additional drilling and assay results are pending.

Ucore Rare Metals Inc. announced drilling results from its Bokan Mountain rare metal project.

During 2010, the company drilled a total of 3,770 meters in 18 holes.

Thirteen of these were infill holes in the Dotson zone.

In addition, three holes were drilled at the Sunday Lake zone to test mineralization along the intrusive contact of the Bokan complex, and two reconnaissance holes were completed within the Geoduck Zone to the south of Kendrick Bay.

To supplement this effort, 45 trenches were channel sampled along the Dotson Zone, an induced polarization geophysical survey was conducted at the Sunday Lake Zone and the company completed an airborne radiometric survey of the area, followed by regional mapping and prospecting.

Significant results from the drilling include 1.98 meters grading 0.83 percent light rare earths and 0.65 percent heavy rare earths in hole LM10-76, 1.88 meters grading 0.83 percent light rare earths and 0.89 percent heavy rare earths in hole LM10-77 and 1.84 meters grading 1.05 percent light rare earths and 0.66 percent heavy rare earths in hole LM10-80.

Assays on other holes are pending.

The company also updated their conceptual resource model for the Dotson zone.

The revised model indicates an estimated 3.5 million to 6.5 million metric tons with grades ranging from 0.76 percent to 1.42 percent total rare earth oxides.

The model also indicates that heavy rare earth elements comprise approximately 40 percent of the total rare earth content in the Dotson zone.

 

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