The 2009 Exploration Program at the MAN, Alaska project included a new ZTEM airborne survey (Z axis Tipper Electromagnetic system), extensive geological mapping and a proprietary fluxgate time domain ground EM surveys (full waveform streaming multi sensor fluxgate array). The 2009 geophysical programs (ground fluxgate TEM, ZTEM, and BHEM) were considered a great success. These very compelling geophysical targets, are the best discovered to date on the MAN property and the foundation for a productive 2010 exploration program.
3D inversions of aeromagnetic data, as well as several widely spaced deep drill holes show a consistent presence of abnormally thick ultramafic bodies with localized deep feeders. Last year’s results add to the evidence that the MAN property is the main intrusive centre for Triassic magmatism that generate the extensive nickel, copper and PGE (platinum group elements) bearing ultramafic intrusions and coeval lavas within the Alaska, Yukon and BC, segments of the Wrangelia terrain. Drill results to date come from the holes targeted using the proprietary ground time domain EM survey (TEM), in conjunction with the new ZTEM airborne survey and previous ground gravity and VTEM airborne surveys.
Interpretation of the 2009 MAN drilling results assays indicates the presence of a disseminated NI-Cu PGE (platinum group elements) concentration build up extends beyond 600 meters in DDH PNI-09-024 and over 1000 meters in DDH PNI-09-025. Geophysical surveys show that these conductive bodies are associated with the strongest Fluxgate TEM anomalies on the property, in addition, strong responses to the BHEM surveys indicates late channel (high conductance channels) conductivity build up beneath the drill holes.
The surveys described below were used to model the interpretation of conductive anomalies on the property. The analysis concludes that the anomalies are deep, large and very compelling.
- ZTEM Survey – has for the first time identified at depth the shape structure, and conductive zones of the mafic and ultramafic intrusions.
- Ground TEM – proprietary long time constant, time domain electromagnetic surveys allowed for deep search (> 800 meters) for high conductance bodies commonly associated with Ni-Cu sulphides that have been missed by previous surveys methodologies.
- Ground and Airborne Magnetic Survey’s – these survey’s help to define the magnetic bodies below surface that often correlate to the ultramafics and mafic rocks on the property. In addition, UBC 3D inversions and Euler 3D inversions are employed to help determine the location of the form, internal structure, and deep kneels or feeder dykes associated with the intrusive bodies.
- BHEM Survey – a borehole electromagnetic survey is performed down the drill hole to detect conductive anomalies within, beside and below the drill hole to aid in the correlation with the new high priority, long time constant, surface TEM survey results constraining more accurate location of the conductor.
One of the most exciting targets from the 2009 geophysical program was the identification of the location for drill-hole PNI-09-025 based on the initial results from the TEM surveys. The hole was drilled to a depth of 1066 metres and terminated due to the limitations of the drill. The BHEM (down hole geophysical survey) showed an increasingly large response towards an anomaly below the hole’s final depth.
Low-frequency borehole electromagnetic surveys (BHEM) were carried out in five of the 2009 drill holes, as well as seven older drill holes. A number of moderate to strong off-hole conductors were detected and are being evaluated as follow-up drill targets for the 2010 program. Three holes (07-001, 09-023 and 09-025) show anomalous increases in late time channels indicative of deep conductors below the base of the holes. These deep conductive zones correlate with high-priority long time-constant surface TEM anomalies.
Extensive geophysical work was conducted concurrent to the drilling program. In particular, a new ground time domain EM system (full waveform streaming multisensor fluxgate array), was deployed extensively through the latter half of the exploration season. This was the first instance of this technology being used in North American nickel exploration. This ground based EM technology developed by Dr. Mark Shore (Magma Geosciences Inc.) provided Pure Nickel exploration team with the ability to collect low-noise late time data under challenging conditions and identify electromagnetic anomalies at greater than 800 metres depth.
Dr. Mark Shore is going to represent example of using of lower frequencies induction coil, SQUID and fluxgate sensors on the nearest PDAC in Toronto: http://www.pdac.ca/pdac/conv/2010/pdf/presentations/ts-mark-shore.pdf.