Figure 5Q. Kalgoorlie Golden Mile, Chaffers Area. EagleEye structural geology and lode correlation.
Objective.
To get detailed structural geology at lode scale from the Australia wide magnetics. For instance, I have never seen the magnetics of the Kalgoorlie Superpit or a detailed magnetics of the specific Kalgoorlie mineralised area. There is none on the publicly published free data. We have previously looked at the lodes seen on EagleEye in the entire Superpit and they ‘roughly’ correlated with the published lode positions.
We are now looking at the southern end of the Superpit in more detail to see if the lode positions can be determined at an larger magnification. When I have looked at other mining areas, and particularly the Chixculub crater, https://www.geotreks.com.au/work/giant-ring-structures/chicxulub-impact-20000-x-enlargement-from-original-seismic-tomography/
the more the image was magnified the more detail was seen and the accuracy improved. Will that be the case in the Superpit?
Observations.
The left hand inset is from Finucane and Jensen 1955 paper of the lodes on the Golden Mile. It shows the lodes at the Chaffers Shaft at the 600 foot level (200 m), I worked there from 1973-76 and know them well. In fact the very last hole I drilled underground, between the Chaffers Lode and 4 Lode on Chaffers, got 9 metres at 9 g/t, on the day the mine closed in 1976!
The Australia wide magnetics are nominally at the surface and so there is expected to be a difference in horizontal lode position because of this depth difference. The main lodes are almost vertical and so should be in position with the EagleEye magnetics but the Morrisons lodes dip to the SSW at 80 – 85 degrees and so should show to the south of the magnetics (black) position.
This is actually what is observed. The main NW lodes are almost exactly where the EagleEye enhancement shows them and the 2 Lode and Morrisons lode are to the south of the magnetics position.
Conclusions.
There is very good correlation between the EagleEye enhancement of the Australia wide magnetics and the published lode positions. The offset of the Morrisons Lode and 2 Lode to the south is exactly what is expected.
The termination of lodes on crosscutting NNE – NNW structures observed in the larger scale plan is repeated on this closer scale There is also more bifurcation of lodes on these structures. I don’t remember them being recorded underground or in the pit. A new ore control?? A new pit mapping tool? 🙂 :)!!
A good result and shows what can be achieved with pattern recognition software!
I could go right down to metre scale on these lodes but I think the point is made 🙂 .