David M. Johnson

Personal Information
 

  • Marital status: Married

  • Nationality: Australian

  • Date of Birth: 28th November, 1967

  • Place of Birth: Melbourne, Australia
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    Objective
     

    Senior position as geophysicist involved in grass-roots and near-mine mineral exploration.

    Professional experience
     

    July 1997 – Present Rio Tinto Exploration Brisbane, QLD

    Senior Geophysicist

  • Zinc-Lead Exploration – Prospect scale interpretation of induced polarisation and gravity data. Definition of areas of interest using Tensor Induced Polarisation. Supplementary use of down-hole IP logging to characterise physical properties and confirm effectiveness of drilling. Regional interpretation of GEOTEM and gravity data.
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    January 1995 – July 1997 Western Mining Corporation/Univ. of Utah Townsville, QLD

    Project Geophysicist – Study Leave

  • Selected to take paid Study Leave from Western Mining Corporation.

  • Enrolled in Master of Science program at University of Utah – nominally 30% course-work/70% thesis research.

  • Thesis research involved development of three-dimensional electromagnetic modeling software to simulate the cross-hole electromagnetic response of a highly conductive orebody in a lossy dielectric host.
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    July 1992 – December 1994 Western Mining Corporation Townsville, QLD

    Project Geophysicist – Queensland

  • Copper-Gold Exploration – Supervised major geophysical exploration program in the region surrounding the Ernest Henry FeOx-Cu-Au deposit. Extensive use of induced polarisation, transient electromagnetics, gravity and magnetics on prospects and mine-site sterilisation program. Regional interpretation of gravity and airborne magnetics. Characterisation of Ernest Henry geophysical response and physical properties using detailed surveys and down-hole geophysics (gamma, magnetic susceptibility, conductivity, IP-resistivity, DHTEM). Joint use of geology and down-hole gamma databases to investigate geochemical dispersion halo of Ernest Henry.
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    December 1989 – July 1992 Western Mining Corporation Kalgoorlie, WA

    Geophysicist – North Eastern Goldfields

    • Nickel Exploration – Regional exploration program at Mt Keith following take-over of ACM, involving compilation and assessment of historical data and detailed follow-up of existing prospects. Target generation using airborne magnetics. Extensive use of detailed ground magnetics, down-hole and moving loop TEM. Supported regional nickel exploration programs of Leinster Nickel Operations, Windarra Nickel Project and Exploration Division.

    • Gold Exploration – Project generation using airborne magnetics and reconnaissance geochemical sampling throughout North Eastern Goldfields. Prospect scale interpretation of ground magnetics, with supplementary physical property measurements.

    • Groundwater Exploration and Environmental Investigations – Interpretation of TEM sounding data in palaeochannel environment to identify drill targets. Involved in discovery of large groundwater resource at Leinster Nickel Operations. Limited involvement in definition of structures involved in leakage of contaminated water from tailings dams using TEM.

    Education
     

    January 1995 – July 1997 University of Utah

    Master of Science/Geophysics

    • Thesis topic: Finite Difference Time Domain Modelling of Cross-Hole Electromagnetic Survey Data
     

    January 1986 – December 1989 University of Melbourne

    Bachelor of Science (Hon.)/Geophysics

    • Thesis topic: Three Dimensional Electromagnetic Modelling

    Publications
     

    Johnson, D., Furse, C., and Tripp, A.C., 1998, FDTD Modelling of the Borehole EM Response of a Conductive Ore Deposit in a Lossy Dielectric: 68th Annual SEG Meeting, New Orleans.

    Johnson, D., Cherkaeva, E., Furse, C., and Tripp, A.C., 1999, Cross-borehole delineation of a conductive ore deposit in a resistive host - experimental design: Submitted to Geophysics

    Professional memberships
     

    Society of Exploration Geophysicists (active member)

    Australian Society of Exploration Geophysicists (active member)

    Interests and activities
     

    Flamenco guitar, hiking, canoeing, family history research, cooking, reading

    References
     

    Ian Ledlie, Rio Tinto Exploration +61 7 3362 8248

    Peter Fullagar, Fullagar Geophysics +61 7 3870 1946

    Bill Amann, Outokumpu +61 8 9334 7333