June Technical Talk

Speaker: Mike McMillan, MSc Candidate & Staff Geophysicist at Newmont Mining Corporation.

Title: Enhancing resolution of 3D-EM inversion models through a co-operative geophysical approach with drilling constraints.

Date: Tuesday June 25th, 2013

Time: 4:30pm

Location: 4th Floor Conference Room, Room 451, 409 Granville (UK Building at Granville and Hastings)

GoToMeeting Details:

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Abstract:

When multiple electromagnetic (EM) geophysical datasets are collected over a common area, and drilling information is available, the goal of a geophysicist is to produce a consistent three dimensional resistivity inversion model which fits the given datasets and adheres to the drilling. This feat is usually easier said than done. At the Antonio high sulfidation gold deposit in Peru, time-domain airborne EM, controlled-source audio-magnetotelluric (CSAMT) and induced-polarization (IP) data were gathered and inverted in 3D to recover a large resistor related to gold hosted silica alteration. However variations between the 3D models were observed which further motivated a subsequent co-operative method in which all the geophysics data collectively worked together to produce one consistent resistivity model. This approach was tackled in a few different ways, and some examples are shown with synthetic datasets that quantitatively demonstrate the improved resolution achieved in 3D inversion models by implementing co-operative inversion methods. These routines were then used on field data, and with the addition of physical properties from drill-holes, one resistivity model consistent with all geophysics and drilling information ensued which helped further image the gold rich resistive zone.

POST-TALK: Those interested are encouraged to head to Moose’s Downunder after the talk.