Galna Moody 4In 2004, the Ontario Geological Survey released several airborne geophysical maps, including Maps 81908, 81909, 81914, 81915, 81919 and 81920, in the Lake Abitibi Area. They cover all of RT Mineral's Galna-Moody properties.
In referring to Map 81909, Block A has two magnetic peaks, both displaying similar intensity. There is a gap of lower magnetic intensity between the 2 stronger magnetic peaks that may be related to alteration with the ultramafic intrusive. I see a steep southerly dip to the intrusive. The intrusive is approximately 1875m long and about 300m wide. With a 75m flight line spacing, this magnetic data is quite detailed.
With respect to Map 81908, Block B shows an oval shaped magnetic anomaly that appears to be from a vertical source. Block C appears to be plunging to the east, while Block D is plunging to the west. The latter two magnetic anomalies are very small and exhibit weaker magnetic intensities. Note for Block D that there are 2 magnetic trends that appear to be radial trends away from the main anomaly, one to the ESE and the second to the SE. Could they be related to the main magnetic anomaly?
In referring to the Shaded Image of the Second Derivative of the Magnetic Field and Keating Coefficients (Map 81915), the east side of Block A, in Galna Twp, shows 3 magnetic peaks, with a narrow fourth magnetic trend overlapping one of the other magnetic anomalies. Almost like a 'mini' thrust fault. I suspect that an east west fault zone is the cause. Just over in Moody Twp., where I had previously inferred an alteration zone, there are 2 east west trends in this area. Not sure of an interpretation for this area!!
Map 81914 shows that Block B hasn't changed, while Block C has 2 magnetic anomalies, with the eastern one having weaker magnetic intensity, thus the previous east plunging direction interpretation. Block D has been affected by an east west fault zone, as evident by the displacement of the diabase dyke to the west. Both radial magnetic trends show up much better.
In 2004, Pierre Keating compiled magnetic maps (Maps 81919 and 81920) using one of his software programs to 'interpret' the magnetic data, called Keating Coefficients, outlining potential kimberlites. It shows all 4 blocks of RT Mineral's Galna-Moody property having the potential of being kimberlites. Wouldn't that be nice!!!!
In reference to the Shaded Magnetic Relief Map (Map 81953), it will be noted that Blocks A and B are on trend with each other, so that they probably have a similar host rock. At the same time, Block C seems to be located on the same stratigraphic plane as the magnetic trend to the west, west of the 2 north south diabase dykes. The same goes for Block D. Again, note the magnetic trend west of the north south diabase dykes, on strike with Block D. Knowing what the rock types are west of the diabase dykes will help to determine the host rocks for both Blocks C and D.