Pogo District heats up
Majors, juniors and prospectors position for exploring gold-rich area
Last updated 2/4/2018 at 6:36am
As gold exploration cools globally, the search for the precious metal is once again heating up in the larger Pogo Mine region of Interior Alaska.
One of the reasons this region continues to be a hotbed of gold exploration is Sumitomo Metal Mining Pogo LLC’s success in finding and expanding new deposits of high-grade gold on its Pogo Mine property, which anchors the Goodpaster Mining District.
Another dozen promising prospects found beyond the borders of the Pogo Mine claims add to the intrigue of an area that stretches for some 70 miles along the Alaska Highway southeast of Fairbanks.
Over the past year, global miners, junior explorers and prospectors have expanded known deposits, discovered new ones, consolidated land positions and assembled geological data – all in the search for another Pogo or Fort Knox mine in this gold-rich region of the Interior.
Sumitomo Metal Mining Pogo – a partnership between Sumitomo Metal Mining Company (85 percent) and Sumitomo Corp. (15 percent) – invested roughly US$15 million on exploration in the immediate Pogo Mine area during 2015, making this the largest exploration program in Alaska this year.
Pogo General Manager Chris Kennedy told those attending the Alaska Miners Association Fall Convention in Anchorage that the exploration targeted nine areas “under our headframe” at Pogo.
While the high-grade underground gold mine does not sport a headframe in the classical sense of the term, the mill facilities do happen to be positioned on an island at the vertex of three high-grade gold deposits – Liese, North Zone and East Deep.
Pogo began operation in 2006 by mining Liese, a zone immediately west of the mill.
In 2010, SMM Pogo discovered East Deep, a twin to Liese that lies immediately east of the mill.
Geological and metallurgical evidence indicates that the Liese and East Deep zones were once a single body of gold-rich mineralization split by a wedge of gold-barren igneous rock (diorite) on which the mill now sits.
The discovery of East Deep – a deposit that is geologically and geochemically similar to the ore-body on which Pogo was founded – has been a boon for the Interior Alaska mine.
SMM Pogo began developing East Deep in 2012 and has mined more than 731,000 tons out of the deposit since 2013. It was not until this year, however, that infrastructure was established to the point that the company considered development complete.
North Zone, a group of higher grade vertical veins to the north of the mill, likely served as a conduit to deliver gold mineralized fluids to the flat-lying Liese and East Deep zones.
This year SMM Pogo had nine drills focused on the discovery and expansion of targets surrounding the mill, including the northern end of the East Deep deposit, North Zone and Pogo South, a southerly expansion of the Liese zone.
Kennedy said this work included some 219,500 feet of exploration drilling – 174,000 feet from surface and 45,500 feet underground – and about 103,000 feet of definition drilling.
Ultimately, the goal is to replenish the gold mined out of reserves at Pogo this year.
Though not all of the results are in, Kennedy said it looks “very, very good” that this year’s drilling will not only replenish about 340,000 ounces of gold expected to be mined at Pogo this year, but also will add to the mine’s life.
On the Brink
Stone Boy Inc., the exploration company credited with discovering the Liese deposit at Pogo, continues to seek new deposits in the larger Pogo area.
Owned by subsidiaries of Sumitomo Metal Mining (95 percent) and Sumitomo Corp. (5 percent), Stone Boy has been exploring Interior Alaska since 1991 and currently holds four properties in the general area of the Pogo Mine – Ink, Monte Cristo, Skippy and Shaw.
Over the past three years, the Ink claims, located about 15 miles (24 kilometers) southeast of Pogo, has been the Japanese firm’s primary focus, including a US$1.3 million program completed in 2014. This work has been completed in partnership with Japan Oil, Gas and Metals National Corporation (JOGMEC), which holds an 18.23 percent interest in the property.
Yuki Beppu, the geologist in charge of Sumitomo Metal Mining America’s exploration in Alaska, told the AMA convention crowd that exploration at Ink has focused on the Brink Core Zone, a bulk-tonnage gold deposit more akin to Fort Knox than the high-grade Pogo mine located about 21 miles (34 kilometers) to the northwest.
In the Brink deposit, Stone Boy has drilled 29 drill holes (8,903 meters) to date. This work has traced the core zone over an area measuring at least 500 meters wide, 1,700 meters long and to a depth of 500 meters. The best hole, DH13-30, cut 514.4 meters averaging 0.427 g/t gold.
Stone Boy’s other promising gold property, Monte Cristo, is located some 40 miles (64 kilometers) west of Pogo.
The Naosi zone, a gold-silver-antimony prospect within the larger Monte Cristo properties, had previously been one of the primary exploration targets of the Stone Boy project. In 2011, the partners released results from drilling Naosi, including intercepts of 7.8 g/t gold, 19.7 g/t silver and 0.1 percent antimony over 7.92 meters; and 22.83 meters grading 4.2 g/t gold, 48 g/t silver and 0.17 percent antimony.
From 2008 through 2012, Stone Boy drilled 84 holes (16,670 meters) at Naosi, outlining the deposit for about 1,500 meters along strike and to a depth of about 500 meters.
Beppu offered an invitation to companies interested in joining the search for another gold mine in the Pogo region.
“Sumitomo Metal Mining is seeking a partner for the Stone Boy project,” said Beppu, who is based in Vancouver B. C.
Pogo district knowledge
He said the Naosi deposit shares a lot of similarities to LMS, a project that Millrock Resources Inc. was given the option to acquire under a larger agreement to acquire Corvus Gold Inc.’s assets in the Pogo area.
As part of the agreement, Millrock acquired West Pogo gold property, which covers the projection of a favorable structure that passes through the Pogo Mine about two miles to the east.
The biggest part of the deal, however, is an extensive geological database from nearly two decades of exploration that Anglogold-Ashanti and International Tower Hill Mines carried out in the Goodpaster Mining District where the Pogo gold mine is located.
The acquisition of the proprietary database and Pogo West property is part of a collaborative agreement with a yet-to-be-named major mining company to seek out high-grade gold deposits in Alaska.
Millrock Chief Exploration Officer Philip St. George said, “With the acquisition of the Anglogold-Ashanti database, our company will have the most comprehensive store of geological knowledge on this district. We will have a distinct competitive advantage for generating new grassroots exploration targets for high-grade gold deposits with our strategic partner.”
If Millrock and its un-named partner decide to further consolidate their holding along the structural trend that hosts Pogo, they may be interested in Aurora Resources’ Money Rock property, a group of claims just north of Pogo West.
Stone Boy’s Shaw project also is part of the block of state mining claims found along the structural trend that hosts the Pogo Mine, located just a couple of miles to the southeast.
As part of its deal with Corvus, Millrock also had the first right of refusal to acquire LMS, a gold prospect about 25 miles southwest of the Pogo Mine.
Back in the game
After spending the last year quietly consolidating a 26,639-acre land position immediately north of Stone Boy’s Monte Cristo property, Great American Minerals Exploration Inc. is gearing up for a US$2 million drill program on its Uncle Sam property in 2016.
“Game,” as the company is commonly known, is no stranger to the Pogo region. In fact, the privately held Nevada corporation first discovered gold on the Uncle Sam property in 1998 and has held onto a position in the region ever since.
Over the past 17 years, Kennecott Exploration, Stone Boy, Millrock and Crescent Resources Corp. have confirmed an intrusive-related gold district that covers more than 30 square miles.
“It is a fantastic district,” Pat Smith, an independent director of Great American Minerals, told the AMA gathering.
Smith, headed Kennecott’s Alaska exploration programs for more than two decades. During this tenure, Kennecott cut deals with Game and others in the region to explore Uncle Sam for three years.
One area of particular interest is Lone Tree where Kennecott Exploration hit “some fantastic intercepts of low grade,” according to Smith.
One hole drilled by Kennecott, USC-011, cut 19.2 meters averaging 2.03 g/t gold at the Lone Tree target.
While intrigued by some long intercepts of low-grade gold in the Lone Tree area, Smith said the best grades have been cut in the Wolf Zone, located in the southern portion of the property just north of Stone Boy’s Monte Cristo.
Millrock and Crescent drilled four holes at Wolf in 2011, all of which cut decent gold mineralization.
WLF-001 cut 2.74 meters averaging 3.63 g/t gold, WLF-002 cut 11.46 meters averaging 4.86 g/t gold, WLf-003 cut 3.05 meters averaging 3.27 g/t gold and WLF-004 cut 2.13 meters averaging 1.81 g/t gold.
Looking to jump back into the gold exploration game, Great American Minerals has re-acquired the properties that make up its historical holdings at Uncle Sam.
“Just in the last year, Game has been able to consolidate the entire claim group we had back in the Kennecott days,” Smith explained.
Game has a budget of US$2 million to fund a phase 1 drill program planned for 2016.
Northern Empire Resources Corp. – a prospect generator with early-stage gold properties in Alaska and Nunavut and a silver property in Mexico – has consolidated a large 60,000-acre (24,282 hectares) gold property in the Richardson District, just a couple miles southwest of the Uncle Sam and Monte Cristo properties.
Like the other properties in the region, Richardson is prospective for intrusive-related gold deposits similar to the high-grade gold found at Pogo, located 45 miles to the east, and at Fort Knox, roughly 85 miles to the northwest.
An estimated 118,640 oz. of placer gold and 2,357 oz. of lode gold have been mined in the Richardson District since 1905.
“Richardson is one of the few gold exploration properties in Alaska which is road accessible, bound on two sides by high transmission power lines, located in an mining friendly jurisdiction, and host to multiple, large gold footprints,” Northern Empire Chairman John Robins summarized.
Northern Empire has divided the enormous land package it has accumulated in the area into two projects – Hilltop and Richardson.
Early in 2015, Northern Empire optioned Hilltop, a portion of the larger Richardson property, to Sonoro Metals Corp.
The partners said the trenching, and soil and rock sampling carried out at Hilltop has confirmed and expanded the footprint of known gold mineralization at this 31,720-acre property.
Highlights from the program include channel samples returning up to 19.45 g/t gold and rock grab samples grading as high as 26.55 g/t gold.
Sonoro President and CEO Kenneth MacLeod said, “The exploration results from both phase 1 and 2 at Hilltop have exceeded our expectations and support our belief that the Richardson Gold District will emerge as one of the most exciting areas for gold exploration in Alaska as we advance this project.”
Northern Empire, meanwhile, completed an independent exploration program on the Richardson property that stretches southeast from Hilltop.
The work program at Richardson primarily focused on sampling in and to the north of Democrat Pit, the site of a 70,000-short-ton bulk sampling program in 1988 that is reported to have produced 2,000 oz. of gold.
Highlights from 23 rock samples collected in and around Democrat Pit include: 71.2 g/t gold and 48.6 g/t silver; 4.6 g/t gold and 111 g/t silver; and 2 g/t gold and 233 g/t silver.
Robbins said the high-grade silver and gold collected from outcrop has refined Northern Empire’s exploration plans for the 2016 season.