b'AEGC 2023Short abstractsUsing automated mineralogy to define indicatorThe methodical integration of effectively processed magnetics mineral signatures around the Julimar nickel-copper- images with outcrop, drill hole, gravity survey and other PGE project, Western Australia. datasets can be carried out at typical exploration scales ranging from district - 1:250 000 - all the way to mine - 1:2500. Alexander Walker 1 Brent I. A. McInnes1 and Patrice de Caritat2 A step-wise zooming in approach maximises geological value interpreted from the data and provides elevated confidence in 1 John de Laeter Centre, Curtin University targeting and exploration field activities.2 Geoscience AustraliaIn the Tanami the use of magnetics data integrated with gravity Indicator minerals are those minerals that indicate the presenceand seismic surveys has outlined the geological context for of a specific mineral deposit, alteration or lithology. Their utilityrare earth and gold deposits at 1:250 000 scale by mapping out to the exploration industry has been demonstrated in a rangemajor structural and intrusive features. At the 1:50 000 scale of environments and across multiple deposit types includingthe search space is refined by the mapping of folds, secondary Cu-Au porphyry, Cu-Zn-Pb-Ag VMS and Ni-Cu-PGE. Recentfaults, splays, intersections, terminations, contacts and intrusive developments in the field of SEM-EDS analysis have enabledcomplexities.the rapid quantitative identification of indicator minerals during regional sampling campaigns. Zooming-in further to the Castella - Watts Rise project area to the north of the Lewis Granite we utilise 50 m line spaced Despite the demonstrated utility of indicator minerals formagnetics data to interpret at 1:5 000 scale. We trace the Killi diamond and base metal exploration in Canada, Russia andKilli unconformity, and important cross cutting structures Africa, there are relatively few case studies published fromelevated in REE mineralisation from soil geochemistry. Airborne Australian deposits. We present the results of an indicatorand ground radiometrics across the area highlights associated mineral case study over the Julimar exploration projecturanium anomalism.located 90 km NE of Perth. The Gonneville Ni-Cu-PGE deposit, discovered by Chalice Mining in 2020, is hosted within a ~30 kmIdentifying and quantifying uncertainty inherent in long belt of 2670 Ma ultramafic intrusions within the westernmineral resource estimates.margin of the Yilgarn Craton.Stream sediments collected from drainage channels aroundAndrew Walthothe Gonneville deposit were analysed by quantitativeUncertainty is present in all mineral resource estimates. mineralogy techniques to determine if a unique indicatorResource reporting codes require public reports of mineral mineral footprint exists there. Samples were processed andresources to be classified using terminology required to analysed for heavy minerals using a workflow developedcommunicate confidence in estimates but the criteria on which for the Curtin-GA Heavy Mineral Map of Australia project.this assessment is based are subjective and applied at the Results indicate elevated abundances of indicator mineralsdiscretion of the Competent or Qualified Person responsible for associated with ultramafic/mafic magmatism and Ni- the public report.sulfide mineralisation in the drainages within the Julimar project area, including pyrrhotite, pentlandite, pyrite andMultiple sources of uncertainty are present in:chromite. We conclude that indicator mineral studieshow the continuity of geological features between points of using automated mineralogy are powerful, yet currentlyobservation provided by drilling and geological mapping is underutilised, tools for mineral exploration in Australianinterpreted;environments. estimation of grades and physical attributes of mineralisation are estimated between points of observation;Maximising value from aeromagnetics surveying inthe consistency of geological information available, or the pressing search for cleaner-energy and rare earthwhether adequate data required to inform decisions required materials. to progress projects are available;bias in interpretations introduced by the previous experience Yvonne Wallace 1 Teagan Blaikie1, David Isles1 and Karl Weber2 of technical personnel involved in the project; and,ESG considerations, of which there is increasing awareness 1 Southern Geoscience Consultantsamongst project proponents, investors and other stakeholders.2 PVW Resources LimitedIndividual projects are affected by a unique combination of The generation of insightful working geological mapsfactors that contribute to uncertainty, in the same manner as allows for the identification, follow up and refinement of keydeposit characteristics are a unique expression of the interplay exploration target criteria across all commodities includingof geological factors responsible for their formation. The rare earths, lithium, nickel, lead, copper and uranium. Modernleverage exerted by different sources of uncertainty in the high sensitivity magnetometers combined with low platformoverall context of a project also varies considerably.noise and well refined quality control processes allow for the identification of subtle anomalism within all terrains includingSources of uncertainty inherent in resource estimates have low magnetic contrast sediments. been the subject of considerable research for a number of years, particularly in the oil and gas sector. These techniques At a ballpark average of $10 per line km, the fixed wingare equally applicable in the minerals space. Techniques that acquisition of aeromagnetics data proves as cost effective nowprovide a range of equally probable but unique depictions as it did 30 years ago. Flight line spacing and flight height canof grade within a resource are well understood. Approaches be selected to provide excellent unbiased spatial resolution, andto assess the potential impacts of uncertainty in geological to suit a range of requirements. interpretations are rapidly emerging.149 PREVIEW FEBRUARY 2023'