The identification of multiple new high-grade copper targets at American West Metals’ Cyclone prospect in Canada has the company contemplating its potential for resource growth at its wider Storm project.
The company’s recent moving loop electromagnetic (MLEM) survey at the Somerset Island site in Nunavut has unveiled what it says are “outstanding” new copper targets that include likely extensions in most directions to Cyclone’s existing 12.1-million-tonne JORC copper resource.
New EM anomalies have also been identified over 1000m along strike from the Chinook deposit (2.2 million tonnes at 1.5 per cent copper) and also around the previous 2023 discoveries at the Thunder, Lightning Ridge and Gap prospects. Management believes it indicates strong potential for extensions to known high-grade copper mineralisation.
American West revealed late last month that it had kicked off its new season’s exploration at Storm and that the MLEM survey was already underway. It also said its track-mounted reverse-circulation (RC) drilling had begun, focusing on historical EM targets close to Storm to identify near-surface, high-grade copper mineralisation.
With the latest MLEM results starting to come in, the tracked rig will likely be parked in about the right place to go on to drill and verify the new MLEM targets as they come to light. A second RC rig is also on its way to the site, while two diamond rigs are already stationed there.
American West Metals managing director Dave O’Neill said: “The scale and strength of some of the new anomalies, and the low false positive rate when using EM systems at Storm, make them compelling targets that are ready to be drilled. The MLEM data has reinforced our belief in the outstanding growth potential of the project and that further zones of high-grade copper mineralisation exist in unexplored areas.”
Management says its MLEM survey is rapidly advancing, with about 22.7 line kilometres of the survey being completed at Storm. The immediate focus is on priority areas to expand higher-grade copper resources and identify new targets for drilling, working west along the southern margins of the graben.
The copper mineralisation at Storm is primarily chalcocite, a copper sulphide with 79.8 per cent copper content and it can occur as massive sulphides in breccias and veinlets. It is accompanied by minor chalcopyrite, another copper sulphide with 34.5 per cent copper content, which occurs on the margins of the mineralisation.
It means that with the MLEM only detecting higher-grade copper mineralisation at Storm, it is possible the potential copper endowment of the area around the EM targets could be higher than indicated from the mere scale of the anomalies. That further highlights the potential for additional resource expansion.
Once the westerly component of the work has been completed, the survey will then work eastwards to complete the survey lines laid out east from Chinook towards the Blizzard and Tornado prospects.
EM is an effective targeting tool at Storm where sulphides are semi-massive to massive because they contrast strongly with the dolomitic host rocks that have no EM response.
The correlation of EM anomalism with the strike trends of the graben points to the strong potential for further discoveries of high-grade copper sulphides in similar settings along the margins of the graben to those known at the current Thunder, Lightning Ridge, Chinook, and Corona copper deposits. About 10km of the graben faults remain under-explored in the southern Storm area alone.
With all of the conductive EM anomalies correlating with high copper grades intersected in drilling, they continue to be compelling targets that may either represent extensions to known deposits or completely new ones. The ongoing MLEM surveys will continue to screen the broader Storm area, with follow-up surveys over some of the preliminary conductors to help filter drill targets.
Planning is also complete and preparations are ongoing for a suite of environmental monitoring and survey activities during this year.
And finally, studies are progressing on a range of beneficiation and processing methods applicable to a variety of ores from the Cyclone and Chinook deposits, while other mining and development investigations continue.
It is encouraging that American West has identified such a solid correlation between geophysical anomalism and mineralisation that translates directly to drill targets, as it is quite rare.
It means the company should be able to efficiently put together a pipeline of targets to be brought quickly to preliminary resource levels and also stage a series of prefeasibility studies into the near to medium future – an important factor given the seasonal limits on field exploration.
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By Doug Bright
