The mining newspaper for Alaska and Canada's North
The mining newspaper for Alaska and Canada's North
International Tower Hill's 10,000-meter drill program hits unexpected zone of high grade ore; metallurgy points to adding a mill
International Tower Hill Mines Ltd. wrapped up a winter drill program at the Livengood gold project about 70 miles north of Fairbanks April 20. The 10,000-meter program that began in February encountered an unexpected area of higher-grade mineralization to the southwest of the 6.7 million-ounce gold resource outlined by previous drilling.
"We are having some good luck in the southwest extension of the deposit. We have run into another higher-grade portion of the deposit," International Tower Hill Mines President and CEO Jeff Pontius told Mining News April 20. "The whole southwest area was a real surprise to us in the fact that we ran into significantly higher-grades than we hit in most of the rest of the deposit with the exception of our Core zone.
Continued encouraging news has prompted the junior explorer to expand its 2009 program at the Interior Alaska gold deposit.
"The tremendous resource growth we achieved in 2008, coupled with numerous highly prospective expansion targets, has fueled the need for an expanded program," Pontius said. "Our primary goals for 2009 will be to maximize the expansion of the Livengood gold deposit, initiate testing of other district-scale targets at the project area and commence initial drill testing of high-grade feeder zone targets at depth."
Higher-grades in the southwest
The previously unexplored Southwest zone, which is easier to drill during the winter months, was the primary focus of the 35-hole winter program at Livengood. International Tower Hill has received assay results from 14 of the 20 holes drilled into the southwest extension of the deposit, revealing an area of higher-grade mineralization that rivals the deposit's Core zone.
MK-RC-0115, the initial hole drilled into the Southwest zone, intersected 68.58 meters grading 1.12 grams per metric ton of gold. The highest grade assay result came from hole MK-RC-0118, which intersected 35.05 meters grading 3 g/t gold and included a 3.05-meter layer that assayed at 24.86 g/t gold. MK-RC-0120, drilled 600 meters south and 400 meters west of the nearest reported 2008 resource hole, intersected 45.7 meters with an average grade of 2.11 g/t gold.
"There is no question that these holes represent a major expansion of the deposit, with grades as good as or better than those found in the Core zone defined last year," said International Tower Hill Vice President of Exploration Russell Myers.
Drill crews also completed 5 infill drill holes to bring continuity to the main ore body and drilled an additional 10 holes in the Northeast zone, an area that the company believes has the potential to greatly expand the size of the deposit. Assay results from the Northeast zone are still pending.
Expanded summer program
Geologists at Livengood have identified about 250 priority targets that they would like to see drilled during the summer program. Pontius said the junior could only drill about half that many with current plans. The CEO, who had just returned from a visit to the project site, is working on yet another expansion of the 2009 exploration program.
"We are looking at possibly increasing the drilling this summer, and we are working on a plan for that now," he said.
Pontius told Mining News that the company plans to add another 5,000 meters to its summer drill program. This expansion would be above and beyond a 5,000-meter expansion that International Tower Hill had announced in early April. It will boost total drilling for 2009 to about 50,000 meters, marking the fourth time the explorer expanded the drill program.
The goal of the 40,000-meter summer program at Livengood, according to Pontius, is to define the deposit's size and to test the extent of its higher-grade component.
The company believes that the higher-grade mineralization encountered in the Southwest zone is on a northeast trend and this suggests that this mineralization will intersect the south end of the currently defined ore body and continue on to the east. Pontius told Mining News that 40 or 50 holes drilled this summer will be in this area.
The company plans to have two or three reverse circulation drills expanding the breadth of the gold deposit, while a single core drill explores for higher-grade feeder zones, which geologists believe will be found at depth.
Metallurgy looks good for a mill
The junior also is excited about metallurgical results coming from the Livengood deposit. On April 15, International Tower Hill reported the latest results to tests which used a combination of grinding, gravity concentration and cyanide leaching of the tails to increase average recoveries to about 89 percent.
The metallurgy results, in combination with discovery of large, higher-grade zones of mineralization, bode well for the possibility of including a mill in the processing circuit. A mill would improve gold recoveries and the economics of the rapidly expanding gold project.
"It certainly looks like, considering the higher-grade component of the deposit, that we will have a milling component to the processing circuit," Pontius said. "That is a positive thing for us because we can get better gold recoveries from the processing circuit."
The ITH President said he estimates about a 0.7 g/t gold cutoff for ore that would be run through the mill, but those numbers will be more definite when the preliminary economic assessment for the Livengood project is complete. The assessment, due in July, will include an updated resource estimate that incorporates results from the winter program, Pontius added.
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.
Reader Comments(0)