The mining newspaper for Alaska and Canada's North
The mining newspaper for Alaska and Canada's North
Constantine Metal Resources Ltd. President and CEO Garfield MacVeigh and the Vancouver B.C.-based junior's Vice President of Exploration Darwin Green returned to Southeast Alaska in 2009 to explore the Palmer project. A copper-rich deposit found in the same belt of late-Triassic volcanic massive sulfide that hosts the precious-metal-rich Greens Creek Mine to the south and the enormous copper-laden Windy Craggy deposit about 35 miles to the northwest.
Raising C$3 million in tough market conditions, Constantine returned to expand the thick zones of massive sulfide mineralization discovered at the South Wall and RW zones in 2007 and 2008.
"We are very pleased to be active and moving forward with a substantial drill program at the copper-rich Palmer project, particularly in a year that has proved extremely difficult for the junior resource sector to secure project financing," MacVeigh said in July. "Palmer is an important new discovery with significant size potential, and we expect 2009 will be an exciting year for the company."
Three mineralized zones
With three rigs churning, Constantine's 2009 drill program at Palmer targeted expanding the footprint of the three thick zones of copper-zinc-silver-gold mineralization discovered at the South Wall target.
Half of the 10 holes drilled at Palmer focused on Zone 1, the uppermost layer of massive sulfide mineralization, and the remaining five holes targeted Zone 2 and Zone 3.
Green told Mining News, "We are taking the drilling out to the west targeting South Wall Zone 1. Zones 2 and 3 are a little deeper and so we are taking those down to depth."
Company geologists deduced that Zone 1 is related to the Main Zone which lies immediately to the southeast of South Wall, while Zone 2 and Zone 3 are of the same age strata as the RW Zone to the northwest.
Two separate discovery holes were drilled on the Palmer Project at the end of the 2007 drill program, one at the RW zone and one at the South Wall. Twelve holes completed in 2008 on the South Wall yielded 17 massive sulfide intersections. Nine of the intersections exceed 20 meters in width.
In late September, Constantine had only received assay results from three of the 10 holes drilled in 2009.
Hole CMR09-23 intersected 21.3 meters grading 2.76 percent copper and 0.50 percent zinc This intersection extends Zone I mineralization 40 meters down dip of CMR08-17, the westernmost drill intersection in the 2008 drill program.
CMR09-24 intersected 9.1 meters with an average grade of 1.90 percent copper, 5.20 percent zinc, 0.30 g/t gold and 26.6 g/t silver, within a broader 18.7-meter-wide zone of mineralization grading 1.16 percent copper, 4.16 percent zinc, 0.30 g/t gold and 29.2 g/t silver, expanding Zone I, 80 meters west and 40 meters updip of CMR08-17.
CMR09-26 intersected 4.0 meters grading 2.09 percent copper, 9.19 percent zinc, 0.22 g/t gold and 22.0 g/t silver. The intersection, located 80 meters down dip and 40 meters west of CMR08-22 is 40 meters deeper than the next deepest Zone 2 intersection.
Complex geology
The geology of the multiple layers of South Wall is complex due to folding and faulting in the area. The 12 holes drilled in 2008, which resulted in 17 mineralized intersections, helped sort the complexity.
Despite the complexities, Green said Constantine's geological model held up to the 2009 drill campaign.
"There is folding, but it is not complicated to the degree you see at Greens Creek," the exploration VP said. "Here, it does seem to be hanging together in terms of having this flat limb that the RW is sitting on, and a steeper limb that the South Wall zones are sitting on, and they appear to be plumbing through the mountain to the other side."
"Overall the model is holding together but it is still fairly early. It is never good to think you understand everything," Green added.
Reunited at Palmer
Though McVeigh and Green may not understand everything about Palmer, they probably know more about the deposit than anybody.
The duo first worked together at Palmer in 1998. At the time McVeigh was president of Rubicon Minerals Corp. and Green was a graduate student earning his master's degree in economic geology from Carleton University in Ottawa.
Green received Carleton's Senate Medal for his graduate work on the Palmer property. His master's thesis, "Geology of Volcanogenic Massive Sulfide Prospects of the Palmer Property, Haines Area, Southeastern Alaska" was sponsored in part by Rubicon.
While MacVeigh was president of Rubicon, that company described the Palmer Project as follows: "The project is located in 'elephant country' and hosts numerous high-grade base-metal showings within rocks that are the same age as the Greens Creek and Windy Craggy deposits." In order to further investigate the mammoth deposit, MacVeigh formed Constantine in 2006.
Green joined his former colleague in Oct. 2008, after spending the previous three years heading up the exploration of Niblack, another Southeast Alaska VMS deposit near Ketchikan.
"With the exciting new developments at Palmer, and after recently reaching several major personal and project milestones at Niblack, it was an opportune time to shift gears and take on the role of VP Exploration at Constantine to help advance the Palmer project," Green said.
First resource
The 10 holes drilled in 2009 will be included in a resource estimate expected to be complete by the end of the year, this will be the first resource calculated for the Palmer project.
To help calculate the resource Constantine had preliminary mineralogical and metallurgical work completed on 2009 drilling. Density measurements have been obtained on split core for all 624 significant assay samples from South Wall and RW zone intersections.
"In a massive sulfide-type deposit, where sulfide content can vary quite a bit, it is really important to characterize the density in detail," Green explained.
The exploration VP said the metallurgy tests are also an important element to estimating the resource of a polymetallic deposit.
Green said future drilling will continue to focus on growing the resource at the South Wall and RW zones.
"We have tested just a small area on one side of the mountain, and we are just trying to trace it into the mountain through to the other side. We know we have massive sulfide on that other side, actually in drill core, 900 meters away," he explained.
Over his more than 16 years of covering mining and mineral exploration, Shane has become renowned for his ability to report on the sector in a way that is technically sound enough to inform industry insiders while being easy to understand by a wider audience.
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