Northstar Gold defines near Surface EM conductor southeast of Cam Copper Mine, Ontario
Northstar Gold Corp. [CSE-NSG; OTC Pink-NSGCF] reported the completion of Pulse-EM surface electromagnetic (EM) and borehole electromagnetic (BHEM) surveys over a 900-metre southeast strike extension of the Cam Copper Mine volcanogenic massive sulphide (VMS) trend, on the 100%-owned Miller copper-gold property 18 km southeast of Kirkland Lake, northeast Ontario.
Cam Copper is a road accessible shaft mine and small-scale, past producer of high-grade ‘direct shipping’ copper ore1,2 that recently returned multiple near-surface high-grade VMS copper drill intercepts.
Crone Geophysics and Exploration recently completed a 3-component, or 3-dimensional surface EM survey that defined a strong near surface conductor with a conductance of 200 Siemens (S), indicating possible massive sulphide mineralization along strike and similar in composition to Cam Copper Mine Zone 2 but with potentially greater thickness.
This potential “Zone 2 Extension Conductor” has a minimum 350-metre strike length and 150 metre depth extent and strikes 319° Az and dips -82 degrees to the northeast. The Zone 2 Extension Conductor is coincidental with several magnetic anomalies located approximately 600 to 900 metres along strike to the southeast of the Cam Copper mine site and could represent the southeast expansion of previously drilled Cam Copper VMS Zone 2 (14.8% copper over 2.5 metres in DDH CC03-23.
Northstar signed a Letter of Intent (LOI) which includes a 6-month lock-up agreement to negotiate acquisition terms with Boston Creek Mines Ltd. for their 100%-owned, 65-hectare Boston Creek Mines property, situated adjacent and northwest of Northstar’s Miller copper-gold property on the historic Boston Creek Copper Trend.
“Northstar continues to advance, enhance and expand the Boston Creek Mines VMS Copper Trend on the Miller copper-gold property by diamond drilling, borehole and surface EM surveys, and strategic acquisition strategies,” stated Brian P. Fowler, P.Geo., President, and CEO of Northstar. “The newly defined, 350 metre near-surface Zone 2 Extension EM Conductor is 750 metres southeast of Northstar’s recent high-grade Zone 2 drill hole copper intercepts at Cam Copper Mine, with signatures potentially representing a large, near-surface VMS deposit. Northstar is positioning to drill test the Zone 2 Extension Conductor later this summer.”
The 200S conductor is characterized by strong late-time channel EM responses indicating persistence to depth and included a STEP response suggesting the presence of highly conductive sulphides within the larger conductive body. In addition to the strongly conductive EM anomaly, additional parallel conductor(s) have also been identified in the footwall and hangingwall of the main conductive body over a strike length of 500 metres; possibly greater as the footwall conductor(s) appear connected to several historic near surface low resistivity IP anomalies along strike to the northwest.
The entire package of conductor(s) could represent stacked lenses of VMS surrounding a sub-seafloor hydrothermal vent area. Previously identified vertical loop electromagnetic (VLEM) conductors present in the hangingwall of the strongly conductive body were also detected in the surface EM survey. The y-component profile section from line 7E highlighted multiple separate and distinctive conductors over a width of 150 metres. Similar Pulse-EM technology and surveys lead to several previous VMS discoveries across Canada, including Hudbay Minerals’ 2003 Lalor VMS deposit discovery in Manitoba.
In addition to the EM survey work, Northstar also completed a 3D inversion of previously collected magnetic data covering the larger Cam Copper area. The subsequent 3D isosurface model of magnetic susceptibility successfully outlined the Zone 2 VMS horizon along with several larger anomalies extending for 900 metres along strike to the southeast of Cam Copper, including one magnetic anomaly only 115 metres to the southeast of the previous DDH CC03-23 intercept grading 14.8% Cu over 2.45m from 116.55m to 119m. A strong historic IP response associated with Zone 2 was modeled between the magnetic anomaly and the hole CC03-23 intercept indicating continuity of Zone 2 along strike towards the southeast. The larger magnetic anomalies located on the Zone 2 VMS horizon that are co-incidental with the newly discovered Zone 2 Extension and footwall EM conductor(s), particularly on line 6E, could represent thicker accumulations of massive sulphides associated with a primary VMS vent area where magnetite stringer zones are common in the footwall sequence.
In early 2024, Northstar previously reported results of a limited prospecting and sampling program covering the southeast extension of the Cam Copper VMS/exhalite trend along the contact with the Round Lake Batholith. The program, while abbreviated due to snow cover, included the collection of 15 grab samples from older workings and gossanous areas. Several semi-massive to massive sulphide samples collected in proximity to the newly discovered large EM conductor(s), and magnetic anomalies returned values in Au (0 – 2.02 g/t Au), Ag (0.15 – 26.9 g/t), Cu (41 ppm – 27,900 ppm), Pb (0.9 ppm – 3340 ppm) and Zn (12ppm – 2070 ppm). These samples, collected from pods or lenses of massive sulphides, represent the surficial expression of distal mineralization along the margins of what is likely a more strongly mineralized VMS envelope highlighted by the strong 200S EM conductor located below the surface and along strike to the southeast of the 2023 sample locations.
A BHEM survey was completed in only 2 of 4 boreholes at Cam Copper (CC01-23 and CC03-23) due to hole blockages and was further hampered by a geomagnetic storm and interference from an adjacent powerline. The initial coil induction survey did, however, identify a STEP response associated with Zone 2, indicating the presence of highly conductive mineralization. A subsequent fluxgate magnetometer survey of hole CC03-23 identified a strong conductor, only 15 metres from the hole, sub-parallel to the hole trace which was later concluded to be a highly conductive cross fault hosting both conductive fault gouge and graphite which channeled current away from both Zone 2 and borehole CC03-23, ultimately preventing full 3D plate modeling of the Zone 2 response. The strong historic IP anomaly and 3D magnetic model of Zone 2 were unaffected by the conductive cross fault.
Northstar intends to follow up on the 2023 Cam Copper trend surface sample and 2024 EM survey targets in the spring of 2024, with a program of prospecting, geological mapping, sampling and a Phase II diamond drill program. Northstar will also conduct surface inspections of historic workings, due diligence of the Boston Creek Mines Property and negotiate acquisition terms.
Northstar’s primary exploration focus is to advance and expand our near-surface, bulk-tonnage gold-telluride and more recently discovered VMS copper mineral deposits on the flagship, 100%-owned Miller copper-gold property.
Cam Copper is a road accessible shaft mine and small-scale, past producer of high-grade ‘direct shipping’ copper ore centred on the historic Boston Creek Copper Trend.
Northstar has recently completed down-hole and grid-scale EM geophysical surveys at Cam Copper Mine to define Phase II drill targets in Q2, 2024.
Northstar is seeking a senior partner to conduct Allied Gold Zone lateral and depth expansion diamond drilling on the Miller property.