b'AEGC 2023Short abstractsSeismic guided minerals exploration. Newmonts Bulk Leach Extractable Gold (BLEG) stream sediment sampling technique was developed over the 1980s Tony Marsh, Sian Bright, Kevin Jarvis, Jai Kinkela, Andrewand 1990s as an efficient and reliable low-level regional Pethick, Greg Turner and Sasha Ziramov reconnaissance screening tool. As gold is a notoriously difficult element to analyse in stream sediments due to highly variable HiSeis field duplicates, the technique was engineered to achieve Large areas of prospective mineral regions are buried byacceptable reproducibility of results at the lowest detection regolith cover. This presents a huge opportunity for minerallimits available at the time. Amongst several discoveries, exploration as new technologies emerge to address thisNewmont BLEG is credited for revealing the world class Batu challenge. New techniques must be able to image buriedHijau Cu-Au porphyry system in Indonesia (Maula and Levet, geological structures in adequate detail for geologists to make1996).informed decisions about the presence of suitable structures toMore recently, exploration has trended away from a focus on host a mineral deposit. Potential field methods provide a broadoutcropping systems into the cryptic world of undercover scale exploration picture but lack the resolution provided bytargeting. This focus has seen Newmonts next generation active source seismic surveys. of geochemical tools emerge; Deep Sensing Geochemistry Whilst the high resolution and significant depth of investigation(DSG) and Terrain Mapping Geochemistry (TMG). Although of seismic surveys has long been known, a significantDSG was first named publicly in 2013, these techniques were impediment to the uptake of seismic techniques in mineralsdeveloped following years of internal and external research exploration has been the complexity of the outputs. We addressin fine fraction geochemistry, applied field geochemical this in two ways. Firstly, we use new seismic processing andand regolith control, and advances in analytical laboratory velocity model building workflows specifically tailored forcapabilities using ultrapure digestions and instrumentation hardrock environments. These provide considerable uplift overpushing elemental detection limits below crustal legacy seismic data sets as well as high quality new subsurfaceabundance.imaging results. Secondly, using these high-fidelity results, weExplorers today are experiencing a geochemical renaissance use new automated, data-driven workflows to provide morewhere these tools, leveraging applied geochemistry geological outputs which can be used to inform key aspects offundamentals are integrated with other advanced minerals systems at multiple scales. exploration tools and datasets to deliver the next generation New automated interpretation techniques adapted from theof discoveries.oil and gas industry using machine learning and artificial intelligence are now being applied to mineral 3D data sets for automatic fault detection. Along with this, seismic inversionBest practices for ultra-high resolution magnetic and is now being successfully employed to generate robust 3Dradiometric statewide merging.rock and rock property volumes incorporating all available drillhole control. The combination of these two approachesSam Matthewsresults in a comprehensive 3D geologic model of structure and stratigraphy at a resolution rarely seen in the mineralsGeological Survey of New South Walesindustry. Statewide geophysical merges are typically created and Our paper will present multiple case histories of how thesemaintained using regional government-funded surveys. The approaches are transforming the way seismic is being usedproducts typically have grid cell sizes between 40-50 m due to advance geological understanding and accelerate mineralto typical regional survey line-spacing falling in the 200-250 exploration under cover. m range. On a statewide scale these products provide an excellent overview of regional geological features. However, any geophysical survey flown at less than 200 m line-spacing has The next generation of surface geochemistry;the finer details aliased out.understanding what that means for covered exploration - a Newmont perspective. Since 2020, the Geological Survey of NSW has been updating and iterating the statewide magnetic merge, and in 2022 Simon Marshall, Sarah Rice and Jeffrey Bigelow released the first updated version of the statewide radiometric merge. These products are created at grid cell sizes of 25 and Newmont 50 m respectively. This accommodates a large suite of high-resolution company surveys flown at 100 m line-spacing As Newmont passes its centenary year, an opportunity isor better. There is a significant improvement in resolution, presented to reflect on a long history of commitment towith four times the data density of the products they are exploration, innovation and technology. Newmonts 102-superseding.year journey has populated the gold explorers toolbox with geophysical techniques as notable as induced polarisation;Geophysical merging is a complicated technique which can however, the parallel story of the development of industry- be enhanced by following a series of best practices in the leading geochemical techniques is untold. Although therepreparatory stages. With a fully documented procedure, are no silver bullets in gold exploration, a 40-year effort byseamless iterations upon existing products with newly acquired Newmonts geochemistry team with a focus on samplingdata are made possible. Additionally, high-resolution statewide theory, data integration, and aggressive field programmes hasproducts form the base layer of even higher resolution regional resulted in proprietary geochemical exploration tools which areproducts, as the Geological Survey of NSW is performing over still seeing active development and deployment. focus regions for critical mineral study.FEBRUARY 2023 PREVIEW 118'