b'Geophysics in CSIRONewsCSIRO: Mapping 3-component magnetic field data alongside core segmentsCSIRO Mineral Resources, in conjunction with the MINEX CRC, are investigating how best to recover information from petrophysical measurements for integration with magnetic field studies and application to mineral exploration. Our first study area is the Cobar Region, where mineralisation is associated with large volumes of pyrrhotite, which is anomalously conductive and chargeable and has substantial remanent magnetisation (in the monoclinic form).A major challenge in applying petrophysical data to magnetic field studies arises from the scale differences between the volumes sampled in petrophysical measurements, and the volumes responsible for the measured geophysical field expressions. We are trying the bridge that gap with high volume petrophysical measurements made with a newly developed mobile petrophysics laboratory. However, for remanent magnetisation studiesFigure 1.An early feasibility test of mapping 3-component magnetic field data alongside core.upscaling using conventional measurements is difficult, timeremanent magnetisation, which changesreduced sampling for this will be guided consuming and expensive. A possiblesubstantially with the rotations. from the mapping of magnetisation solution being developed and testedalong the core. We also hope to gain new by CSIRO is a methodology using aWe expect these results to provide a moreinsights into the structural controls on 3-component magnetometer run inrepresentative estimate of the total coreore formation in the Cobar region from a fibreglass track of square sectionmagnetisation, and will compare resultsmagnetic fabric studies on the pyrrhotite alongside oriented segments of corewith conventional remanent magnetisationusing anisotropy of magnetic susceptibility to map its magnetic field (Figure 1).measurements. Extraction of some samples(AMS) measurements.Repeat measurements followingfor conventional measurement is still rotations of the core allow separation ofrequired to provide demagnetisationClive Foss induced magnetisation, which changesanalysis of the stability and genesis ofCSIRO Mineral Resources only slightly with the rotations fromthe magnetisation, but we hope that theClive.Foss@csiro.auFree subscription to Preview online Non-members of the ASEG can now subscribe to Preview online via the ASEG website. Subscription is free. Just go to https://www.aseg.org.au/publications/PVCurrent to sign up. You will receive an email alert as soon a new issue of Preview becomes available. Stay informed and keep up-to-date by subscribing now!!NB: ASEG Members dont need to subscribe as they automatically receive an email alert whenever a new issue of Preview is published.AUGUST 2022 PREVIEW 26'