by joe mihelcic, geophysicist clearview geophysics inc. ontario exploration & geoscience...

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By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7, 2010

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Page 1: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

By Joe Mihelcic, Geophysicist

ClearView Geophysics Inc.

Ontario Exploration & Geoscience Symposium“New Ideas, Revisiting Past Discoveries”December 7, 2010

Page 2: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Any induced polarization survey that utilizes boreholes to: Inject currentor Measure potentials

Page 3: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Most common scenario is that favourable mineralization intersected in at least one borehole: Test if target is chargeable Quantify in or around borehole Determine Orientation/Direction/Extents Prioritize available geophysics and

drilling data

Page 4: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Many configurations and methods available: Mise-a-la-masse In-hole Pole-dipole and dipole-dipole Hole-to-hole Gradient Etc. etc.

Page 5: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Keep it simple Configure using basic physics Include external data Consider cost/risk vs. benefit/reward

E.g., tomographic mode for mineral exploration?

Page 6: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Favourable mineralization detected in a number of boreholes spread over wide area

Favoured theory suggests overall mineralizatoin plunges towards the northwest

Attempt BHIP to test this theory from borehole with good intersection 158.2 m -193.6 m

Page 7: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Run a simple dipole-dipole detection log to determine if intersected zone is chargeable:

Page 8: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Charge the target zone with Current Electrodes above and below the zone: C1 = 162 m (VG at 176 m) C2 = 225 m

Read potentials on surface Ensure lines at 90 degrees to BH

direction Tie-in to surface BH’s (bush crash)

Page 9: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Axis ‘A’ identified along chargeability trend

Page 10: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Axis ‘A’ identified along chargeability trend

Page 11: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Compare to available geophysics data

Page 12: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Compare to available geophysics data

Page 13: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Compare to available geophysics data

Page 14: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Focused post-processing of previously acquired surface pole-dipole geophysics data Inversion modeling Overlay drilling locations in 3D

Page 15: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,
Page 16: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

- Not available on website download due to size

- Available upon request

Page 17: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

Which boreholes drilled through zone?

Re-examine logs to find anomaly source

Recommend tighter drilling along source axis if favourable intersections already encountered

Page 18: By Joe Mihelcic, Geophysicist ClearView Geophysics Inc. Ontario Exploration & Geoscience Symposium “New Ideas, Revisiting Past Discoveries” December 7,

BHIP requires more customization than standard surface arrays

Inversion modeling useful in some cases, at end of process, especially for 3D visualization

A method to further prioritize surface IP results