1 / 26

Lessons Learnt from Three Massive Sulphides Test Sites

This article discusses the findings and challenges faced in testing three massive sulphide sites, their impact on AEM surveys, and the development of new interpretation tools for geophysical exploration methods.

jackiemiller
Download Presentation

Lessons Learnt from Three Massive Sulphides Test Sites

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lessons learnt from three massive sulphides test sites Li Zhen Cheng, Denis Bois, UQAT Michel Chouteau, Ecole Polytechnique Michel Allard, Noranda (now is Xstrata) David Fountain,Richard S. Smith, Jean Lemieux, Marc A. Vallee, FugroAirborne Surveys Pierre Keating, GSC

  2. Geological provinces in Québec Abitibi greenstone Belt

  3. 600 m 700 nT/s (off time) Py Cu Zn semi-massivesulphide New Insco 800 m Iso

  4. Gallen deposit

  5. pH = 2.3 Aldermac

  6. Summary • Iso-New Insco : simple geometry in a resistive host • Test the performance of MEGATEM system. • Gallen:Main body mined out and residual massive sulphides are submerged in acidic water with surrounded metal fence. • Look at the impact from these unfavourable conditions to AEM surveys. • Aldermac: small and deep pods under tailing dump in a hydrographic basin - conductive overburden. • Challenge for MEGATEM system?

  7. What have been done? • Field tests • Two base frequencies of 90 Hz and 30 Hz • Height attenuation tests • Reverse flight direction tests • Transmitter off • Research • Data processing & visualization • Anomalies classification • Modeling and interpretation

  8. What we have learnt?

  9. L301 L501 90 Hz 30 Hz N Iso copper rich zone 90 Hz 30 Hz

  10. MEGATEM flights over Iso deposit at different altitudes (line 100501) 35000 fT 35000 fT 461 m 461 m Bx Bz 35000 35000 371 m 371 m 35000 35000 274 m 274 m 100000 100000 187 m 187 m 300000 300000 122 m 122 m 250 m 250 m 500 m 500 m 750 m 750 m 1000 m 1000 m

  11. 450 350 channel 6 channel 20 channel 6 overburden conductance = 1.2 S channel 20

  12. 700 nT/s 700 nT/s 0 0 700 nT/s 700 nT/s 0 0 700 nT/s 700 nT/s 0 0 0 0 Basalt Basalt Diorite Diorite 250 250 Diorite Diorite Massive sulphide Massive sulphide Rhyolite Rhyolite 500 500 Dacite Dacite Basalt Basalt 750 750 Andesite Andesite (m) (m) In the down-dip direction In the up-dip direction Bx Bx By By Bz Bz

  13. W E 30 o 60 o 60 o 30 o Plate model: 600 m in width, 800 m in deep extension at 50 m depth X up - dip down - dip Z

  14. a b c d X old X new Z old Z new

  15. 3D modeling tools for EM data interpretation • Maxwell • Plate • LeroiAir • Emigma • MacroAir • ArjunaAir • EmQ • LokiAir (EMIT_Au) (U_Toronto) Thin sheet Polyhedron (PetRos_EiKon) Prism (CSIRO_Au) 2.5 D Sphere (GSS_Au) 3 D

  16. 30 S 20 S 55 S 40 S

  17. Gallen deposit

  18. Gallen deposit

  19. Aldermac deposit

  20. 10000 pT/s dBx/dt dBx/dt 30 Hz 30 Hz 0 10000 pT/s dBz/dt dBz/dt 0 Aldermac deposit Line 401 Line 501 measured measured measured measured 10000 pT/s dBx/dt dBx/dt 0 Thick prism Thick prism 10000 pT/s dBz/dt dBz/dt 0 Thick prism Thick prism 0 3 km 0 3 km

  21. Conclusion The present project to enhance the MEGATEM technology has been a successful collaboration between universities and industry. New objective Develop new interpretation tools for geophysical exploration methods

More Related