More exploration approved at Icy Cape
Alaska Mental Health Trust Land Office officials are spending the winter reviewing the results of last year’s drilling campaign and preparing for another at their Icy Cape heavy mineral prospect.
Those results were promising enough for the Alaska Mental Health Trust Authority Board of Trustees to approve $3 million in October to spend on more exploratory drilling next year, according to Trust Land Office Executive Director Wyn Menefee.
The Icy Cape prospect is a long stretch of coastline about 75 miles northwest of Yakutat in Southeast Alaska owned by the trust at the entrance of Icy Bay that appears to hold world-class deposits of several heavy minerals. The entirety of the area is roughly 48,000 acres and stretches for more than 30 miles along the Gulf of Alaska coast.
“We have a lot more to do in the sense that we didn’t cover any of the western portion of the property,” Menefee said in an interview. “We also need to do some more on the eastern side of the property. There’s just more to do before you have a better picture of where everything’s located.”
Trust Land Office leaders have stressed that they are still in the preliminary exploration phase of evaluating the prospect but early drilling samples from the broad delta at the point of the cape indicate the ore there could be up to 40 percent heavy minerals.
Overall, an average of 26 percent of the sands are heavy minerals, according to the Trust Land Office’s 2016 annual report.
The minerals of value in the “ore” — which is mostly old beach sands — are roughly equal portions of epidote and garnet in the areas of highest concentration with small amounts of zircon and even gold.
Epidote and zircon are semiprecious gemstones. Garnet has also been used as a gemstone for hundreds of years, but more recently the hard mineral has been put to use as an industrial abrasive on sandpapers and in sandblasting applications. It is also used in water filtration; garnet’s small pores allow for the passage of liquid while catching some contaminants.
If developed, the Trust property would be the only source for garnets on the West Coast, Land Office officials have said.
The Trust Land Office manages roughly 1 million acres of land across Alaska for real estate and resource development purposes, the proceeds of which go to fund the Alaska Mental Health Trust Authority’s work to benefit Alaskans with mental health and addiction challenges.
Menefee said there is a misconception about the project that mining Icy Cape heavy minerals would literally mean digging up the beach.
Much of the area is forested, he added, and portions of it have been logged.
“It’s the course of time that creates these sandy forelands; so even though they are considered beach sands, it’s not the beach,” he said.
The sands that comprise the substrate are the result of two sediment patterns coming from opposite directions, those materials that have eroded and washed down from the steep mountain faces above and sediments that tidal and wave action have pushed up to the shoreline.
Most of that drilling has been done right from the logging roads that are already there, Menefee said. The area also has an airstrip.
The drilling activity — and any future mine — doesn’t and won’t resemble the hard rock mines many people associate with the industry.
Most of the drilling is to less than 100 feet down and it’s done with a sonic drill rig that uses vibration, not water, to make its way down.
“It just vibrates its way down. We may go 75 to 100 feet, something like that, and then we take out the sand core samples,” Menefee described. “It’s a pretty low-intensity drilling program.”
Because it’s a placer deposit, the mine would be “much more akin to gravel operations,” he added.
Accordingly, the minerals would be sorted either using water, gravity, vibration, magnets or a combination of the processes, Menefee said, noting there is no need for chemical leaching.
Trust Land Office revenues have varied greatly over its 22 years of existence, as money from timber and land sales and other resource projects has come and gone.
Since 2011, its annual revenue has been between about $9 million and $16 million.
Income from an Icy Cape mine — either as a royalty-collecting passive landowner or an active partner — could multiply the Trust Land Office’s annual revenue several times over and continue for decades, leaders have said.
Menefee also emphasized that development is still a long ways off, saying it’s “way too preliminary” to even forecast a development or partnership structure and what role the trust would play in that.
“I think that likely we are going to have anything from a few to several more years (of exploration) and a lot depends on the results of our drilling, the distribution of what we find,” he said. “It’s hard to tell right at the moment how long that (drilling) program will last before we would move towards an actual mine.”
Between exploration and development the Trust Land Office might also demonstrate the viability of the prospect with prototype sorting equipment, depending on what potential mining company partners want to see, Menefee said as well.
The simplicity of the operation and the fact that it’s all on trust, or state, land means federal permits and the often lengthy and costly environmental impact statement review process won’t be needed, according to Menefee.
However, he again noted that permitting a full mine operation is a long ways off.
“We are attempting to keep the communities and the public informed of where we’re going. We just held public meetings in Cordova and Yakutat and we intend to keep doing that after each field season to let people know where we’re at,” Menefee said.
Elwood Brehmer can be reached at [email protected].