b'AEGC 2021Short abstractsin a Kalman filter, compared to using GNNS and gravimeterSome of the noble gas isotopes (20Ne, 22Ne, 36Ar, 38Ar) contain data alone. The project also produced gravity data at sub-mGalsignatures characterising mantle fluids or meteoric waters, noise levels using the NDL and gravimeter data, even withoutwhile radiogenic isotopes (4He, 21Ne, 40Ar, 136Xe) allow the including GNNS data in the Kalman filter. assessment of fluid ages. Measurements from fluid inclusions indicate the origin of the fluids the mineral precipitated from, 148: Attenuation of ice-sheet reverberations inuseful to characterize the genesis of ore bodies, and provide evidence about different stages of the evolution of minerals teleseismic P-wave receiver functions or rock formations, such as pressure-temperature conditions Mr Dale Harpley 1 and Dr Steve Hearn2 during formation and provenance, evolution history and ages of geofluids.1 Velseis The new vacuum mineral crushing system uses the same fully 2 Velseis Pty Ltd automated noble gas analysis system used for groundwater Teleseismic P-waves receiver functions (PRFs) in ice-coveredsamples since 2016, which since 2019 operates with a High-regions are contaminated by reverberations within the iceResolution Noble Gas Mass Spectrometer (Helix MC Plus). sheet. The density contrast at the ice-bedrock boundary causesThe preparation system purifies the noble gas fractions and these events to appear with very high amplitudes on the PRFs.measures the rare isotope ratios in groundwater and pore fluids, The crustal conversion events which are commonly used forincluding 3He/4He 21Ne/20Ne and the stable isotopes of xenon.identifying lithospheric structure are concealed by these iceAn external getter system added this financial year will enable reverberations. the measurement of samples from natural gas or crude oil The measured lag-times (time with respect to the initialfor their noble gas content and isotopic composition. Such P arrival) of the ice phases provide an opportunity formeasurements characterise the origin of the noble gases a Generalised Linear Inversion (GLI) to predict ice-layer(mantle, crustal, meteoric) and radiogenic time scales of fluid parameters (thickness, P- and S-wave velocities). The ice- movement and can assess the extent of water contact of the phase lag-times can be matched to a synthetic ice-layer PRFhydrocarbon phases. This information is not available with other created with the Thomson-Haskell matrix formalism. Nonconventional methodologies and characterizes the migration uniqueness is overcome using constraints on the body-wavepathways of the hydrocarbon fluids before and during velocities. accumulation in hydrocarbon reservoirs.A non-causal Wiener filter is designed to compress the ice-layer model PRF into a peak at zero-time. When applied to150: Yaour seismic survey: Defining a complex 3D a synthetic ice-crust model PRF, ice phases are significantlystructural framework with high resolution seismic datareduced, and crustal phases are shifted to lag-times of an ice-free crust PRF. In theory, the filter assumes that the PRF of aMr Graeme Hird1, Dr Peter Turner2, Dr Greg Turner 1 and multi-layered earth is the convolution of individual layer PRFs.DrDoug Jones2The receiver function does not strictly satisfy this assumption1 HiSeis Pty Ltdand some noise is produced. However, the signal-to-noise of2 Perseus Mining Ltdfiltered crustal-phase events is significantly improved. The filtering of real-data stacked PRFs is successful at attenuatingHiSeis conducted a high-resolution 3D seismic survey over the ice-phase events. It is possible to identify the Ps conversionYaour gold deposit in Cte dIvoire in early 2020 for Perseus from the Moho. Mining. The survey extended over a 3 km x 6 km area and These two algorithms provide a practical approach to predictingimaged the geology to depths beyond 4 km. A 20 km 2D ice and crustal thicknesses in ice-covered regions, such asseismic survey complementing the 3D survey was acquired Antarctica and Greenland. For example, at Concordia Base,to provide broad context for the 3D survey and test for similar Antarctica, our GLI algorithm predicts ice thickness of 3.15 km,structural settings beyond the main survey area.within 4% of measurements from core data. Wiener filtering ofThe Yaour deposit is hosted within a thick basalt sequence PRFs suggest crustal thickness of around 43 km. comprised of massive and pillow basalts. The basalt is not magnetic and therefore magnetic surveying provides limited 149: Noble gases: a versatile exploration tool for water,structural insight into the Yaour mineral system. The seismic minerals and hydrocarbons survey clearly images a series of low-angle east and north dipping thrust faults, linking structures between thrusts and a Dr Axel Suckow 1, Dr Cornelia Wilske2, Dr Christoph Gerber1, Drconjugate set of sub-vertical faults.Alec Deslandes1, Mr Punjehl Crane1 and Dr Dirk Mallants1 The highest grade gold discovered to date at Yaour is found in 1 CSIRO Land and Water the low-angle east-dipping faults and the seismic shows how 2 University of Adelaide these continue beyond current drilling.Noble gases are applied as a standard tool in AustralianIn our paper we will show how the faults at Yaour are imaged groundwater research since the CSIRO noble gas facility wentvia several mechanisms: These are:into operation in 2016. We expand this facility to supportReduced rock competency associated with the disruption of mineral and hydrocarbon exploration. the rock mass proximal to the faults;A new vacuum mineral crushing system in operation since 2020Alteration haloes proximal to the faults, where mineralising allows the measurement of noble gases and their stable isotopefluids are interpreted to have utilised the permeability composition in fluid inclusions entrapped in mineral grains.enabled by faults; andAUGUST 2021 PREVIEW 88'