Friday, March 30, 2012

World Class Gold Discovery - The 2009 PDAC Thayer Lindsley Award in Economic Geology

Finding a world-class gold deposit is a rare, historical, event indeed. To actuate such an event requires much detective work, individuals with open minds, several pairs of field boots, a strong will, curiousity to find what's over the next hill, a frontiersman spirit and one of the biggest guns available!
The PDAC's Thayer Lindsley Award is the most coveted award in the world of mining.  It's nothing like the Nobel Peace Prize: one has to earn the Thayer Lindsley award.

Those mama-boys who survive behind desks, kissup at staff meetings with their clean underwear, spit-shined shoes, perfumed underarms and clean shaving faces are not men of this caliber – it requires a frontiersman mindset, living in solitude, the dangers of the wild that may include wrestling bears, kicking snakes off outcrops, suffering swarm after swarm of blood-sucking mosquito's and black flies, fighting mountain lion or two for road kill just to get a get to a treasure that the rest of us can only dream of.  Yet, seven geologists from North America did this in the 1980s.

The 2009 Prospectors and Developers Association of Canada’s conference in Toronto, Canada, attracted more than 20,000 mining industry delegates to what is considered the largest mining conference in the world. The 2012 PDAC Conference is anticipated to attract nearly 30,000 members: more people than most towns in North America, more people than in any city in the entire state of Wyoming! Each year, the PDAC honors some of the greatest economic geologists in history with the Thayer Lindsley Award. An award that carries the namesake of one of the greatest geologists in North America. Thayer Linsley (1882-1976), was inducted into the Canadian Mining Hall of Fame and considered by many to be the greatest mine finder in history. Those who follow in his footsteps are presented a prestigious award at the PDAC Conference each year in memory of this great geologist.

In 2009, the PDAC Thayer Lindsley Award was shared by a group of seven geologists from the now defunct Western Gold Exploration and Mining Company (WestGold) along with mine developers from NovaGold (who came much later) for discovery of a major international gold deposit in Alaska.
To put this discovery into proper prospective, all we need to do is look at a few of the great gold mines in North America. The great Homestake gold mine in Lead, South Dakota produced 39.8 million ounces of gold over 100 years. At today’s gold price of $1,700 per ounce – this would amount to nearly $68 billion in gold. But much of the gold was sold for $20 to $35/ounce. Homestake was discovered in 1876 and produced gold for more than 100 years until it closed in 2002 after the mine had reached a depth of more than 8,000 feet.
Another great gold deposit, Cripple Creek in Colorado, was found in 1890. Up through 2005, the district produced an astounding 23.5 million troy ounces of gold. And the great gold districts of Nevada, which typically is listed as the largest gold producer in North America, also produced considerable gold, but this is misleading in that the individual mines of the state produce less gold than the great Homestake. So the Homestake ore body is the model economic geologists shoot for.

In Canada, several gold mines of note, such as the Giant Mine near Yellowknife, produced about 7 million ounces of gold from 1948 to 2004; the Golden Giant mine north of Lake Superior produced 6 million ounces during its lifetime. The great Con mine in the Yellowknife greenstone belt of Canada, produced about 5 million ounces of gold.

In the late 1980s, WestGold began a grass roots exploration in Alaska, hunting for the so-called ‘Elephant’ or giant gold deposit in Alaska. The company also imported the Bima Dredge to Nome to mine gold from the Bering Sea. A 14-story dredge, one of the largest ever constructed. It was the perfect senario - mining gold offshore at Nome to finance the search for lode gold inland. Its the stuff TV shows are made of.

WestGold hired a crew of consulting geologists to search for a lode deposit in Alaska. Dr. Paul Graff led the crew and was well known for exploration in Wyoming and Chile. He, Mark Bronston and Richard Garnett decided to bring in Dan Hausel from Laramie, Wyoming.

At that time, Hausel had already discovered a new gold district likely to compete with Cripple Creek, started a couple of gold rushes, mapped several gold and diamond districts in the Cowboy state including greenstone belts with potential for gold, and would go on to find several dozens of gemstone deposits to rival any in the world. Hausel would later leave Wyoming in disgust due to corupt politics that others said could compete with Chicago.  Hausel had planned to live out his life at the Geological Survey at University of Wyoming, but took early retirement in 2006 for ethical and moral reasons to leave Wyoming to the Thermopolis political gang. It was a sad day for Wyoming: hundreds of anomalies, mineral deposits and more than a 1,000 square kilometers were mapped by Hausel who lifted Wyoming from a territorial status in geology to a state filled with gems, diamonds, gold and other resources. He would go on to write about many of these deposits in more than a thousand books, papers, maps and abstracts producing more scientific documents that the entire survey.

So the group of geologists headed off to Alaska. In the Snow Gulch – Donlin Creek area in the middle of nowhere of the Kuskokwim Mountains of southwestern Alaska had produced a couple of tiny, rough, cornflake-shaped gold flakes with ragged edges. This was a major clue. This gold does not transport more than a few feet from its source. Thus, this was a target.

On the nearby hillsides, the group found gold associated with arsenopyrite, secondary silica, and stibnite in an intrusive belt that was traced for more than 5 miles! Something that was unheard of.  Gold was recovered from in Omega, Lewis, Quartz, Ruby, Snow and Queen Gulches, drainages that all cut Donlin Creek felsites (the gold-bearing host rock).

But this giant gold mine ended the career of a gold company. Problems in management left the company in fragmented, and the property was left for someone else to pick up.  Abd like most great gold discoveries, the geologists almost never receive any gold - just a few dollars for their work.

Years later, NovaGold picked up the gold discovery. Based on the 2009 plans of NovaGold, the property will be one of the largest gold mines in the world by 2015. Mine permit applications were submitted in 2009 and construction was to begin by 2012. The WestGold group had identified a group of felsic sills and dikes hosting gold in quartz veinlets and breccias with higher values associated with arsenopyrite and stibnite that intrude a thick sequence (>5000 feet) of folded graywacke, sandstone, and shale.

NovaGold reports mining is anticipated at 1.5 million ounces per year from ore that averages 0.07 to 0.08 troy ounce per tonne.

The WestGold crew who made this discovery was unable to attend the 2009 meeting with the exception of Richard Garnett who accepted the award for his group (two of which have since been laid to rest). Each person listed on the award provided as much input to this discovery as everyone else.

The 2009 Thayer Lindsley Award for an International Mineral Discovery was chiseled in granite. It states that the award was “Presented by the Prospectors and Developers Association of Canada to the exploration team of WestGold for its part in the discovery of the Donlin Creek gold deposit, Alaska”.  In alphabetical order - Mark Bronston, Richard Garnett, Paul Graff, Dan Hausel, Bruce Hickok, Toni Hinderman, Robert Retherford.  It is notable that three of the individuals who made this world-class gold discovery had spent much time in Wyoming.

1988 Field Crew at Donlin Creek-Snow Gulch Alaska showing three of the gold discoverers. Standing far left is Robert Rutherford and far right is Dr. Paul Graff. Sitting on the right is Dan Hausel (photo courtesy of Dan Hausel).

All seven of these geologists now walk in the footsteps of Thayer Lindsley.  Years later, Richard Garnett increased his fame by being part of a discovery team on a major nickel deposit in Canada and W. Dan Hausel had already found a Cripple Creek-type gold deposit in Wyoming. He is known for many discoveries of other gold, diamond, and colored gemstone deposits.