Timmins5Airborne Geophysics
Map 82053 Magnetic Vertical Gradient
The one thing that stands out to me on this map is the weak donut shaped magnetic anomaly, which has its western side located along the western shore of Dougherty Lake, and the eastern side of this magnetic feature in the middle of the lake. The diameter of the magnetic signature is about 400m. Could this be a sulphide lense above a stringer/stockwork zone, that may be host to a VMS target?
On the eastern portion of RTM's Timmins property, west of Greenoch Lake, there is a NNW trending magnetic trend that could be associated with a diabase dyke. However, since the dyke is the same strike direction as the local lithology, the magnetic anomaly may not be a diabase dyke and should therefore be confirmed on the ground.
Just north of Dougherty Lake, there are 3 small isolated magnetic anomalies that could be of interest!
Map 82047 Magnetic Total Field and Electromagnetics
There are 4 distinct areas of strong GEOTEM conductors, 1 is on Daniel Johannsson's (DJ) property to the southwest, and 3 on RTM's Property. Two on RTM's Property have direct magnetic correlation, while the third conductor near the west shore of Dougherty Lake appears to flank on the western side of the weak donut shaped magnetic anomaly. However, the strong conductor just to the west of Greenock Lake is located very close to what could be a NS diabase dyke, so the magnetics here may be related to a potential diabase dyke, until proven otherwise.
Map 82028 Electromagnetics
As mentioned above, there are 3 strong GEOTEM conductors within RTM's Property, having direct magnetic correlation. It is possible that the east end of the conductor northeast of Dougherty Lake has been disrupted by the major north-south Gibson Lake Road Fault. The DJ property has one conductor just south of Dougherty Lake, and is located very close to the southwestern claim boundary of RT Minerals. The depth is approximately 90 metres. If we presume that the direction of dip of the lithology is towards the east in this area, then it is quite conceivable that the conductor will be dipping into RTM's property, at depth.
A strong conductor, located along the western shore of Dougherty Lake, is correlating with the flank of the broad magnetic feature mentioned above. It's depth has been estimated between 87m and 104m. Note the offset of this conductor, with the one to the south on DJ's property. Could there be an east-west fault here?
The conductor directly northeast of Dougherty Lake is believed to be correlating with Drill Hole TT96-16, while the conductor just to the west of Greenock Lake exhibits good conductivity, appears to have a westerly dip as indicated on the magnetic contour lines, and is estimated to be between 73m and 101m deep. This interpreted westerly dip seems to agree with the synclinal structure that was indicated on Figure 4 in Open File Report 6042.
Assessment File 42A07SE2003/42A07SE2003
In 1998, Geoterrex-Dighem flew a frequency domain helicopter EM and Magnetic survey for International Canalaska Resources Ltd that covered most of this area. The results were mixed, with most EM anomalies graded either 1 or 2 (7 being the top grade), meaning a conductance of less than 5 siemens. The system intercepted the conductor near the west shore of Dougherty Lake, as well as the conductor near the southwest corner of the RTM Property. However, one will note that these two DIGHEM conductors are located approximately 150m west from where the GEOTEM conductors are located. Take a look at the 2 maps, both Map 82028 and the map in Assessment File 42A07SE2003/42A07SE2003.
My explanation on the above. Since the DIGHEM frequency domain EM system doesn't have quite as good a depth of penetration as the GEOTEM time domain EM system, it means that the DIGHEM system will detect conductors closer to surface. The time domain system, having a better depth of penetration ability, will therefore intercept the same conductor, but a little deeper. In this case, somewhat down dip. The latter then would generally give you the direction of dip. With the conductor near the southwestern corner of RTM's Property, plus the conductor near the west shore of Dougherty Lake, the direction of dip will then be to the east.
The DIGHEM EM system did not intercept either the 2 targets north of Dougherty Lake or the strong conductor in the East Block, east of the Gibson Lake Road and west of Greenoch Lake.
There were two weaker GEOTEM conductors intercepted in the northern part of the Timmins Twp Property. One is located just off the west side of the Gibson Lake Road, and a second conductor immediately west of Greenoch Lake, about 200 metres. Both should be investigated.
Observations
Two interesting observations. First, except for DDH 95-1, put down by Royal Oak Mines in 1995, neither the GEOTEM system nor the DIGHEM system intercepted any bedrock conductors in any of the areas where several of the drill holes were put down!!! Second, Drill Hole 95-1, south of Dougherty Lake, was targeting an IP anomaly, and as it turns out, the collar was positioned right over a strong GEOTEM conductor. However, from there, it was drilled to the west!! If we believe that the direction of dip of the lithology in this area is to the east, then they completely missed the airborne conductor. A revisit to the older IP data may be worthwhile in order to explain why the drill hole collar was set up where it was. In the meantime, this conductor is still a viable base metal target, which can be drilled from RTM's Property.