b'Conferences and eventsNewsAEGC 2019: ASEG Honours and AwardsASEG Gold Medal: David ClarkThe ASEG Gold Medal is awarded from time to time for exceptional and highly distinguished contributions to the science and practice of geophysics by a Member, resulting in wide recognition within the geoscientific community. The ASEG President announced at the ASEG Awards Ceremony held at the AEGC in Perth that the ASEG Gold Medal has been awarded in 2019 to David Clark.This award specifically recognises Davids exceptional and distinguished contributions to the profession, both in Australia and internationally, through his leading research, publications and presentations in magnetic petrophysics and its application to magnetic field survey design and magnetic interpretation, over a 40-year period.After graduating from Sydney University in 1974 with a BSc (First Class Honours) majoring in physics, David took a gap two years in London and worked as a scientific staff consultant at the GK Bureau in London, before returning toDavid Clark receiving the Gold Medal from ASEG President Ted Tyne.Australia to work as a Research Assistant in the Department of Geology and Geophysics at the University of Sydneyanomalies, which significantly perturb theof hydrothermal alteration in porphyry for two years. ambient geomagnetic field. Dave showedcopper and iron-oxide copper-gold In 1978 David joined Ken McCrackensthat the effects of self-demagnetisationsystems.CSIRO Division of Mineral Physics as anfrom these strongly magnetic bodiesLater David worked with CSIRO on Experimental Scientist. It was whilst atoriginally led to serious errors, particularlytensor gradiometry in multidisciplinary Mineral Physics that, through Professorin interpreted dip, accounting for theteams collaborating with DSTO, the US Don Emerson at Sydney University, heinitial mis-targeting of drill holes. CorrectStrategic Environmental Research and became involved in a research projectdips were calculated after allowing forDevelopment Program, the Canadian on basic magnetic models incorporatingthe self-demagnetisation. This example,National Research Council and Defence both anisotropy and remanence. Hereand others from this period, served toR&D Canada, developing SQUID-he achieved much, especially his owndemonstrate to exploration geophysicistsbased tensor gradiometer systems for development of equations for modellingthe importance of anisotropy ofsubmarine detection from airborne ellipsoids, on which he was the firstsusceptibility, self-demagnetisation andplatforms. This led to many new to publish in the public domain. Heremanence. mathematical relationships that Dave was awarded an MSc in geophysicsIn conjunction with this work, Dave tookwas able to exploit and bring back into from Sydney University in 1984 for hisup the role in 1986 of Senior Researchgeophysics, including the investigation thesis topic Magnetic properties ofScientist at CSIROs Exploration Division,of multiple-order magnetic gradient pyrrhotite -applications to geology andwhere he specialised in magnetictensors for localisation of a magnetic geophysics. petrophysics and its application todipole and interpretation of magnetic From 1979 to 1992 Dave was the leadmagnetic field survey design andgradient tensor data using eigenvector researcher for four consecutive threegeological interpretation of magneticanalysis and the novel concept of the year internationally supported AMIRAsurveys. normalised source strength and a review projects on the Applications of RockDuring the 1990s and early 2000s, Daveof methods for determining remanent Magnetism to Mineral Exploration,played a leading role on further AMIRAand total magnetisations of magnetic projects that served to demystify manyprojects that integrated petrologysources.magnetic modelling enigmas. Forand petrophysics through his uniqueIn CSIRO Minerals Down Under Flagship example, the anomalies associated withunderstanding of magnetics, petrologyprojects Dave was intimately involved in several mineralised Au-Cu bearing quartz- and alteration systems. These projectstwo main developments: (i)developing magnetites in the Eastern Mt Isa Inlier intypified this period of Daves career andtools for downhole magnetic Queensland give rise to large magneticled to a major review of magnetic effectsmeasurements and (ii) a surface 27 PREVIEW OCTOBER 2019'