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 

Geologists must resist 'pigheadedness'

Technology advances, ore deposit models fail to trump boots on the ground and keen observation in mineral exploration successes


Last updated 12/19/2010 at Noon

As the last days of the decade tick by, I am tempted to look back on 2010 and distill the year in a few sentences. I'll resist and opt for a bunch of sentences similar to some I recently dumped on the Society of Economic Geologists, an exploration-focused scientific organization of which I am a card-carrying member. Those words prompted more than a few heated responses, both supportive and not so supportive ("You're a pin-head" is the one that will probably stick with me longest).

Some years ago, the brilliant mineral economist and geophyschologist Doug Silver presented his findings regarding the process of mineral discovery in general and more specifically, what it was that led some people or organizations to be more successful than others at discovering mineral deposits? His work showed a propensity for new discoveries of a specific metal to come in distinct waves over finite periods of time.

Deposit types like gold, porphyry coppers, roll-front uraniums and volcanogenic massive sulfides have each had their success waves, sometimes in multiple time events.

The temptation has always been to attribute this discovery bubble to the formulation and efficient application of new ore deposit models that allow explorers to discover more deposits more efficiently.

It seems intuitively obvious that, once a new model is designed, we should become better at discovering mineral deposits because we can apply the awesome power of technology and experience to the process of mineral discovery.

Yet the equally informative exploration geologist Dick Sillitoe once presented the results of a study that concluded that discoveries do not come faster with increasing application of money and technology. His conclusion, one that displeased the clients who had paid for the study, indicated that boots on the ground and keen observation were the most effective ore deposit discovery tools. Technology and experience play important roles but nothing beats first-hand experience.

With some notable exceptions, information generated from a new discovery is eagerly sought by other exploration geologists trying to find the next deposit of this new type. These criteria soon become widely disseminated and often morph into a ore deposit model whose criteria are so restrictive that they apply only to the original ore deposit that actually generated the model! In truth, we would often be time and money ahead if we simply discarded those models immediately upon formulation. In reality, these new models get applied rigorously and, more often than not, unsuccessfully.

So it was no surprise that my left-lateral neurons started firing when I heard of a new psychological study that suggested geologists were much like the populace at large in being somewhat hidebound when it came to pre-conceived ideas.

University of Michigan researcher Brendan Nyhan's new research, entitled "When Corrections Fail: The persistence of political misperceptions," runs to 50 gassy pages and was directed at political campaign psychology.

But the upshot of his findings has wider applications and is both starkly simple and unsettling: humans tend to be more likely to believe things that agree with our pre-conceived ideas, regardless of how unsupportable that idea becomes.

Perhaps equally disturbing, we tend to dismiss those beliefs that do not support our previously formed ideas and accept those beliefs that do support biases.

In some cases, Nyhan's research found that contradictory but correct information, provided after conclusions had been drawn, actually strengthened a person's desire to hold on to their misperceptions, rather than correct them, a phenomena known as the backfire effect.

Psychologists call the process of gathering only that information that agrees with your preconceived convictions "goal-directed information processing" a pleasant sounding bit of euphemistic jargon! In an exploration geologist, we call goal-directed information processing "pig-headedness," a bit harsh perhaps, but bang-on most of the time.

Put another way, we tend to see what we believe.

While Nyhan's research shows that geologists are not alone in sometimes being stubborn, mulish, inflexible and obdurate, we need to be mindful that not all orebodies are created alike and that many of the working models that now exist were created by people thinking outside the box.

Perhaps that sometimes mining critic Mark Twain was correct when he said, "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so."

Western Alaska

Fire River Gold Corp. announced the first results obtained from its 28,000-meter drill program at the Nixon Fork copper-gold mine.

Significant intercepts include N10-007, which returned 37.0 grams per metric ton gold over 3.6 meters, including 77.9 g/t gold over 1.1 meters and hole N10-015, which returned 27.56 g/t gold over 1.4 meters.

N10-007 was drilled in the North Star zone approximately 1,000 meters from the mill, and hole N10-015 was drilled at Southern Cross approximately 680 meters from the mill.

Three zones were targeted for a total of 19 drill holes: Whelan, North Star and Southern Cross.

Four drill holes for a total of 738 meters tested the Whalen, seven drill holes for a total of 767 meters tested the North Star and eight drill holes for a total of 906 meters tested the Southern Cross zone.

All zones tested during the surface drill program have not been mined in the recent past and continue to demonstrate prospective areas that may provide additional mill feed to the mine.

A total of 6,700 meters have been drilled to date, of which 2,400 meters were on surface.

Millrock Resources Inc. announced that it has staked 46,502 acres, or 17,223 hectares, over the Humble property in the Togiak Terrane approximately 80 kilometers, or 50 miles, northeast of Dillingham, Alaska.

The claims cover multiple geophysical targets with coincident surface geochemical anomalies.

Historical drilling and recent geophysical and geochemical surveys indicate the potential for copper-gold-molybdenum porphyry-style mineralization.

The Late Cretaceous magmatic complex that hosts the prospect is comprised of magnetite-rich pyroxenite overprinted by porphyry-style mineralization.

Circular to semi-circular conductive zones, possible sulfide bearing, were detected by airborne geophysical surveys and surround the magnetic anomalies.

Zoned, multi-element, surface geochemical anomalies overly the geophysical targets and are indicative of porphyry mineralization.

The Humble property, also known as the Kemuk prospect, is centered on a strong magnetic anomaly that was identified and drilled by Humble Oil Co. for iron ore in the 1950s.

More recent sampling of the old drill core identified zones of anomalous platinum, ranging between 30 and 105 parts per billion.

A limited drill program is planned for 2011.

Interior Alaska

Silverado Gold Mines Ltd. provided new geochemical sampling results from its Eagle Creek gold-antimony project in the Fairbanks District.

In addition to gold, the vein-faults samples in 2010 host anomalous amounts of silver, antimony, arsenic and bismuth.

Six of the nine test samples from the vein-faults had between 0.142 and 1.30 ounces per ton gold and between 0.25 and 1.5 oz/t silver.

The samples that had the highest bismuth values also had the highest gold values.

Three mineralized vein-fault structures have been identified: Vein-Fault #1 (historic Scrafford mine), Vein-Fault #2 and Vein-Fault #2A. Vein-fault #1 is 9 to 19 feet wide, trends east-west and has been traced on strike for more than 2,200 feet.

The other two vein-faults (Vein #2 and #2A) are northeast-trending mineralized zones that have widths of 5 to 6 feet and strike lengths in excess of 1,000 feet.

Vein-Fault #2A may be the on-strike extension of Vein-Fault #2, but more trenching is required to confirm the actual continuity of the structures.

Corvus Gold Inc. announced initial drilling results from its LMS gold project under option to First Star Resources Inc. During 2010 First Star drilled three diamond core holes totaling 1,103 meters within the Camp Zone area.

The goals of the 2010 drilling program were to: 1) expand the stratiform gold-bearing graphitic quartzite breccias horizon; and 2) confirm the extent of high-grade gold vein feeder zones in the lower gneiss zone.

Intersections in the stratiform breccia zone include 11.6 meters of 3.0 g/t gold and 13.9 g/t silver, including 4.4 meters of 4.9 g/t gold and 19.0 g/t silver in drill hole LM-10-39 and 2.8 meters of 8.2 g/t gold and 4.6 g/t silver, and 9.1 meters of 1.6 g/t gold and 15.4 g/t silver, including 2.1 meters of 4.8 g/t gold and 6.0 g/t silver in drill hole LM-10-38.

Intersections within the feeder vein zone include 3.5 meters of 12.5 g/t gold, including 0.8 meters of 43.9 g/t gold, in drill hole LM-10-39 and 2.9 meters of 12.5 g/t gold and 6.0 g/t silver and 1.5 meters of 4.4 g/t gold and 2.3 g/t silver in drill hole LM-10-38.

These results have highlighted the presence of both gold-silver and silver dominated styles of mineralization on the project.

International Tower Hill Mines Ltd. announced some impressive results from its 65,000-meter 2010 drilling program at their Livengood gold project.

Extensive infill and deep drilling in the southern part of the Core Zone has intersected the highest grade gold mineralization over the largest intercepts to date below the floor of earlier grid drilling.

Significant results include hole MK-RC-0458, which intersected 112 meters of 2.63 g/t gold from what appears to be a broad feeder zone covering an area at least 400 meters by 400 meters and extending into the SW Zone.

Other significant Core zone mineralization included 77.72 meters grading 1.10 g/t gold in hole MK-RC0429, 51.82 meters grading 1.06 g/t gold in hole MK-RC-0433 and 74.67 meters grading 1.29 g/t gold in hole MK-RC-0449.

Higher grade mineralization also was intersected within the upper oxide zone of the deposit with intercepts of 85.3 meters of 1.1 g/t gold in hole MK-RC-0452 and 13.7 meters of 2.6 g/t gold in hole MK-RC-0445.

Full Metal Minerals announced the 2010 drilling results from its 5,096-meter core drilling program at its Fortymile silver-lead-zinc project.

The 2010 exploration program has extended the strike length of massive carbonate-replacement mineralization at the LWM deposit to over 950 meters.

The program at LWM included step-out drilling along strike on 50 meter centers, as well as select infill drilling.

To the southwest, stepout hole LWM10-64 intersected multiple zones, including 5.89 meters true width averaging 7.38 percent zinc, 13.82 percent lead, 0.09 percent copper and 198 g/t silver.

A multi-element soil anomaly continues to the southeast along the Ketchumstuck fault, which controls the replacement mineralization at LWM. Infill hole LWM10-68 intersected 4.40 meters true width averaging 23.71 percent zinc, 23.63 percent lead, 0.07 percent copper and 314 grams of silver per tonne.

The deposit is open to expansion to the northwest.

LWM10-71, which is the northwestern most hole completed to date on the prospect, hit 1.28 meters true width averaging 4.38 percent zinc, 8.74 percent lead, 0.08 percent copper and 121 g/t silver.

At least two subparallel zones of mineralization have been encountered within dolomitized marble host rock, with the primary zone located adjacent to the Ketchumstuck fault zone.

In the southwestern area of LWM, surface oxidation is locally variable in the upper zone.

In some areas, it extends to over 200 meters below surface; the lower zone is typically less oxidized, with primary sulfide minerals commonly located at surface.

In the northeast, surface oxidation is much shallower.

The company is completing an initial metallurgical test work program to be released in the near future.

Other prospects also were explored in the 2010 field program.

At Eva, high-grade surface mineralization may occur as a "chimney" of carbonate replacement mineralization that was missed by surface drilling.

Drill hole EVA10-01 intersection 1.1 meters averaging 2.35 percent lead, 1.43 percent zinc and 70.0 g/t silver, however other shallow holes did not intersected significant mineralization.

At West Eva, broad of zones of anomalous mineralization, particularly silver, was observed within quartz-carbonate stockwork.

No significant mineralization was encountered at the Oscar prospect.

The company is currently planning an aggressive follow-up drilling program for 2011 to expand the LWM deposit.

Alix Resources Corp. announced that it entered into an agreement with Hidefield Gold Ltd. and Mines Trust Co. to acquire up to a 70 percent interest in the Golden Zone gold-silver-copper project in the Chulitna mineral belt.

Exploration work at the project since 1970 includes 136 core holes totaling 18,750 meters, 62 reverse circulation holes totaling 5,500 meters, 121 surface cuts and trenches totaling 5,500 meters and 1,100 meters of underground workings, with well over three quarters of this work done on the Breccia Pipe.

Additionally, several tens of thousands of meters of ground geophysical surveys and a close-spaced helicopter-borne aeromagnetic and electromagnetic surveys have been completed, and over 1500 rock chip samples and 2200 soil samples have been collected on the property.

At a 1.03 g/t gold cut-off, the measured and indicated resources at the project stand at 253,000 ounces of gold, 1,180,000 ounces of silver and more than 6 million pounds of copper at an average grade of 2.81 g/t gold, 13.1 g/t silver and 0.10 percent copper.

The company has begun a revised resource estimate using additional drilling results from Hidefield's 2006 program.

Exploration in 2011 will include follow-up on the Cohio prospect, 10 kilometers south-southwest of the main resource area, where 2006 exploration by Hidefield revealed three consecutive grab samples collected along a roughly 1-kilometer traverse that returned 9.7, 15.0 and 111.0 g/t gold.

Harmony Gold Corp. and Full Metal Minerals Ltd. have agreed to terminate the option agreement made between the two companies relating to the Lucky Shot gold project near Hatcher Pass. Under terms of the exit agreement, Full Metal will return 2 million Harmony common shares and will grant to Harmony 50 percent of all net proceeds derived from the sale of the Lucky Shot mill and equipment. Full Metal also was to make a nonrefundable advance of US$250,000 on the net proceeds on or before Nov. 30. Full Metal is under no obligation to sell the mill; however, in the event it wishes to keep the mill, it shall pay an additional amount of US$250,000 to Harmony on or before June 15, 2012.

Alaska Range

Kiska Metals Corp. reported additional drilling results from its Whistler project.

The company completed a total of 16,594 meters of drilling in 35 holes on the project in 2010.

New drill results include hole WH10-24, drilled at the Raintree West target, which returned 83.0 meters of 1.2 g/t gold, 11.8 g/t silver, 0.06 percent copper, 0.53 percent lead and 1.08 percent zinc within a larger interval that averaged 0.47 g/t gold, 5.4 g/t silver, 0.04 percent copper, 0.23 percent lead and 0.51 percent zinc over 299 meters.

This mineralization is dominated by lead-zinc-bearing veinlets interpreted as late-stage features developed peripheral to high temperature porphyry-style mineralization.

Two additional holes were completed at Raintree West.

Both were collared east of holes WH10-24 and WH09-02 and drilled to the west, intersecting a large fault zone that may bound or offset mineralization to the east.

No significant results were returned from these holes.

Hole IM10-15 was the final hole of the 2010 drilling campaign at the Island Mountain prospect.

This hole tested a new target area of disseminated pyrrhotite mineralization hosted in diorite, with nearby rock samples returning results of 1.9 g/t gold and 0.52 g/t gold.

The hole intersected anomalous gold geochemistry along its entire length primarily with disseminated pyrrhotite in diorite.

However the higher grade intercept of 13.7 meters averaging 3.69 g/t gold corresponds with intense feldspar alteration and local brecciation within an envelope of disseminated magnetite.

A total of 1,305 soil samples and 181 rock samples were collected on Island Mountain in conjunction with detailed and reconnaissance scale mapping.

In the vicinity of the Discovery Breccia, soil and rock sampling has expanded the target area to 2-kilometers by 1.5 kilometers, or 1.24 miles by 0.96 mile, in size as defined in a roughly northwest-oriented gold (>175 parts per billion) and copper (>320 parts per million) soil anomaly encompassing strongly anomalous rock results.

A new north-trending anomaly of the same strength has been defined by a 2 kilometers by 1.2 kilometers, or 1.24 miles by 0.76 mile, gold-copper anomaly north of the Cirque Zone.

Both of these broad anomalies contain zones of much higher soil geochemical response, exceeding 375 parts-per-billion gold and 800 parts-per-million copper.

Additional drilling is planned for 2011.

175 parts per billion) and copper (>320 parts per million) soil anomaly encompassing strongly anomalous rock results. A new north-trending anomaly of the same strength has been defined by a 2 kilometers by 1.2 kilometers, or 1.24 miles by 0.76 mile, gold-copper anomaly north of the Cirque Zone. Both of these broad anomalies contain zones of much higher soil geochemical response, exceeding 375 parts-per-billion gold and 800 parts-per-million copper. Additional drilling is planned for 2011.

320 parts per million) soil anomaly encompassing strongly anomalous rock results. A new north-trending anomaly of the same strength has been defined by a 2 kilometers by 1.2 kilometers, or 1.24 miles by 0.76 mile, gold-copper anomaly north of the Cirque Zone. Both of these broad anomalies contain zones of much higher soil geochemical response, exceeding 375 parts-per-billion gold and 800 parts-per-million copper. Additional drilling is planned for 2011.

Southeast Alaska

The Beard Co. announced that it did not participate in the 2010 exploration at the Yakutat gold project with partner Geohedral LLC. As a result, Beard's interest in the project has been reduced to 24.19 percent. The company indicated that the most recent test work failed to indicate commercial quantities of gold or silver and have shown lower than previously estimated volumes of magnetite and ilmenite in the Black Sands area of the project.

Ucore Rare Metals Inc. announced that it retained Collison Minecon Inc. to complete initial mine scoping, engineering and design work on a prospective heavy rare earth mine and processing facility at the its Bokan - Dotson Ridge project.

The company also announced results from its field exploration efforts at the project in 2010.

The work confirms that the Dotson Zone, with an average aggregate width of approximately 50 meters, contains a minimum of 25 mineralized dikes and veins.

The zone dips steeply to the north, with a delineated strike length of 2,140 meters and a defined vertical extent of 450 meters.

The zone is open both at depth and on strike.

Significant channel sample results from the Dotson zone include 2.04 meters grading 0.507 percent total rare earth oxides, 3.07 meters grading 0.456 percent total rare earth oxides and 7.20 meters grading 0.485 percent total rare earth oxides.

The company expects to release its first-ever industry-compliant resource estimate shortly.


Reader Comments


Powered by ROAR Online Publication Software from Lions Light Corporation
© Copyright 2018