b'AEGC 2023Short abstractsinfluenced by basement and Moho surfaces from the gravityis well suited for geophysical methods; nickel sulphides are inversion study. Faults were extended beneath the Moho.generally dense, very electrically conductive and chargeable The basement and Moho surfaces guided fault and horizon(King, 2007). In particular, electromagnetic methods are suitable interpretations where no seismic data was available. Whilebecause of a very large conductivity contrast between nickel informed by modern rifting models, this work is not purelysulphides and host rocks. The extreme conductivity of massive model based, interpretations are constrained by previous work. NiS can cause the decay constant of a potential resource to be very large (Smiarowski and Macnae, 2013), necessitating low-This approach has resulted in a western Otway Basin interpretationbase frequency or ground EM surveys. Ground EM surveys can focussed on the Portland Trough. This new work indicates potentialbe time-consuming, very costly, and suffer in difficult to access for a previously unrecognised Late Jurassic or Early Cretaceousterrain.half graben at the base of the Portland Trough. Elevating the prospectivity of the Portland Trough for multiple resources. In the airborne community, much research has focused on decreasing the operating base frequency to improve detection Hydrogen gas storage prospects in the offshoreof targets like massive NiS. In the last 5 years, advances in receiver Gippsland Basin. suspension and receiver construction have made airborne electromagnetic (AEM) low-base frequency operation possible Mark Bunch and greatly improved the ability to explore for NiS. We discuss the changes made to the Helitem, helicopter time domain EM, The Gippsland Basin has been a prolific petroleum producingsystem to enable low base frequency operation at 6.25 Hz.basin that was recently thought to be the ideal end point for a local Carbon Capture and Storage (CCS) value chain. PreviousWe then show an example of a low base frequency Helitem studies have demonstrated sufficient sealing capacity abovesurvey targeting Nickel performed in the Julimar Region of known structural closures to Latrobe Group reservoirs thatWestern Australia. Of particular interest is the detection of could accommodate millions of tonnes of CO 2as petroleumanomalous conductivity outside of the magnetic extent of the production winds down. The aim remains to establish a near- Julimar Complex.shore opportunity for Geological CO 2Sequestration (GCS) with secure sealing capacity to significant closure beneath theApplication of high-resolution airborne EM and threshold depth for sustaining CO 2in a supercritical state. magnetic data for geotechnical information over Another prospective use for Latrobe Group reservoir rocks hastailings facilities, examples from the Quadrilatero emerged. The Hydrogen Energy Supply Chain (HESC) projectFerrifero area, Brazil.began shipping liquefied hydrogen from the Mornington Peninsula to Japan in early 2022. Hydrogen generation methodsDarren Burrows and Adam Smiarowskifor energy supply require intermediary storage systems to smooth the peaks and troughs of supply and demand. TheXcaliburGippsland Basin provides a variety of prospective UndergroundWe present an overview of an ambitious geophysical Hydrogen Storage (UHS) opportunities in the form of knownprogramme undertaken by Vale to characterise both tailings closures to Latrobe Group reservoir units. Sealing capacitystorage facilities (TSF) properties around existing mine sites as to hydrogen gas is approximately equivalent to that ofwell as an exploration programme for iron ore. This resulted in methane meaning closures to natural gas fields should be23 survey blocks being flown. There are a large number of mines viable. However, there are other considerations such as howin Minas Gerais where technical approaches and surviving prone a containment system would be to hydrogen losses byrecords for TSF properties are not at the same standard as at dissolution, chemical reactions or microbial consumption. modern mines. In some cases, there are no records regarding This study evaluates the viability of UHS within the Latrobedam construction. Geophysics presents a non-invasive, cost-Group reservoir system across the Central Deep. The followingeffective method of characterising these dams. However, factors are considered: hydrodynamic modification of closure;in places, ground geophysics is not permitted because of sealing unit thickness and capacity; a threshold depth that isHSE concerns. Also, given the number of mine sites, ground both as shallow as possible but deep enough to limit microbialgeophysics would be an onerous endeavor.hydrogen consumption and ensure competitive hydrogenAirborne geophysics is thus a compelling solution. There density. When these factors are considered together, the mostare two main reasons for airborne acquisition: (1) HSE for prospective known closures for hydrogen storage appear to beconducting ground surveys on top of the existing earth dams those of the Bream and Luderick gas fields. Western parts of theand tailing ponds and (2) speed of acquisition. To properly Marlin and Barracouta fields also show some potential. characterise the site, data must be collected in multiple lines over the dam, pond and the immediate surrounding area.Improving nickel exploration with a purposefully designed airborne electromagnetic system, with anTo characterise the dam, very near surface information is required. Frequency domain EM presents the best available example from Julimar, Western Australia. near-surface sensitivity of airborne geophysical techniques. The Darren Burrows and Adam Smiarowski Resolve system was used due to its wide frequency range of 400 Hz to 140 kHz. In order to enhance sensitivity to magnetic Xcalibur material in the ground, Resolve was flown with a transverse horizontal magnetic gradiometer.Manufacturing of electric vehicles is continuing a remarkable growth rate, necessitating an increase in exploration for nickelTo ensure the correct interpretation of the complete earth and PGEs, as well as other minerals. Nickel (NiS) explorationresponse in these topographically complex settings, the data is FEBRUARY 2023 PREVIEW 84'