This report provides background information about the Ginninderra controlled release Experiment 3 including a description of the environmental and weather conditions during the experiment, the groundwater levels and a brief description of all the monitoring techniques that were trialled during the experiment. The Ginninderra controlled release facility is designed to simulate CO2 leakage through a fault, with CO2 released from a horizontal well 2 m underground. Two previous subsurface CO2 release experiments have been conducted at this facility in early and late 2012, which have helped guide and develop the techniques that have been applied herein. The aim of the third Ginninderra controlled release experiment was to further the development of detection and quantification techniques, and investigate seasonal effects on gas migration. Particular focus was given to plant health as a diagnostic detection method, via physical, biochemical and hyperspectral changes in plant biomass in response to elevated CO2 in the shallow root zone. Release of CO2 began 8 October 2013 at 4:45 PM and stopped 17 December 2013 at 5:35 PM. The CO2 release rate during Experiment 3 was 144 kg/d CO2. Several monitoring and assessment techniques were trialled for their effectiveness to quantify and qualify the CO2 that was released. The methods are described in this report and include: - soil gas - eddy covariance - mobile surveys - Line CO2 concentrations - groundwater levels and chemistry - plant biochemistry - airborne hyperspectral - soil flux - electromagnetic (EM-31 and EM-38) - meteorology This report is a reference guide to describe the Ginninderra Experiment 3 details. Only methods are described in this report, with the results of the experiment published in conference papers and journal articles.

The hyperspectral HyLoggerTM instrument for collecting high resolution spectra data of drill core and drilling chips is a widely used and powerful in mineral and energy exploration, including sediment hosted mineralisation and hydrocarbons. It enables mapping of hydrothermal, diagenetic, and weathering assemblages, clarification of stratigraphy, and determination of primary mineralogy. This report presents key results of hyperspectral data from the HyLogger-3TM instrument collected from drilling in the Southern Stuart Corridor (SSC) project area in the Northern Territory conducted as part of Exploring for the Future (EFTF)—an eight year, $225 million Australian Government funded geoscience data and information acquisition program focused on better understanding the potential mineral, energy and groundwater resources across Australia. The results show that HyLogger plots are in most cases in the most effective means of identification of stratigraphic contacts. HyLogger plots are also especially effective and determining the depth and mineralogy of weathering and distinguishing provenance in shallow transported material such as palaeovalley fill and alluvium. Geological observations are however still crucial, especially in determining texture, which cannot be determined by the HyLogger scans or from photographs of chips and core, and in cases where contamination obscures or confuses the spectral signals. Weathering in the SSC can be determined by the appearance of dickite and poorly crystalline kaolinite. This allows a better determination of base of weathering than visual means: generally based of the presence of oxidised iron phases such as goethite and haematite (which are not definitive where the rocks already contained these prior to weathering), or where oxidised iron deposition has not occurred. This aids in depth of weathering mapping from regional AEM data. The ability of the HyLogger to discriminate between swelling (montmorillonite) and non-swelling (kaolinite, dickite) clays is potentially significant in the prediction of aquifer properties and the validation of borehole MR methods. The detection of zones of potential dolomitisation and dedolomisation through mineralogy (presence of dolomite and possible secondary calcite and magnesite, respectively) in carbonate units has the potential to similarly predict properties in carbonate units, through the potential increase in porosity/permeability of the first and decreased porosity/permeability of the second.

<div>Earth observation is a fast and cost-effective method for greenfields exploration of critical minerals at a continental to regional scale. A broad range of optical satellite sensors are now available to mineral explorers for collecting Earth observation information (EOI) at various spatial and spectral resolutions, with different capabilities for direct identification of mineral groups and/or species as well as selected chemical elements. The spectral resolution of many of the latest imaging spectroscopy satellite systems (e.g., PRISMA - https://www.asi.it/en/earth-science/prisma/; EnMap - https://www.enmap.org/; EMIT - https://earth.jpl.nasa.gov/emit/) allow the mapping of the relative mineral abundance and, in selected cases, even the chemical composition of hydrothermal alteration minerals and pegmatite indicator minerals, such as white mica, chlorite and tourmaline. More specialised hyperspectral satellite systems, such as DESIS (https://www.dlr.de/eoc/en/desktopdefault.aspx/tabid-13614/) feature a very high spectral resolution (235 bands at 2.55 nm sampling and 3.5 nm full width half maximum) across parts of the Visible to Near-Infrared (VNIR) wavelength range, opening up the possibility for direct mapping of rare earth elements, such as neodymium. The pixel size of the imaging spectroscopy satellite systems is commonly 30 m, which can be sufficient to map hydrothermal footprints of ore deposits or surface expressions of typical rare element host rocks, such as pegmatites and carbonatites. However, airborne hyperspectral surveys still provide a higher spatial resolution, which can be essential in a given mineral exploration campaign. Selected multispectral satellite systems, such as ASTER (https://terra.nasa.gov/data/aster-data) and WorldView3 (https://resources.maxar.com/data-sheets/worldview-3) do have bands at important wavelength ranges in the shortwave infrared, but not with high enough spectral resolution&nbsp;to clearly identify many indicator minerals for critical minerals deposits. Most publicly available satellite imagery comprises multispectral systems that are focussed on the VNIR, such as Landsat and Sentinel, but which allow the direct identification of only very few mineral groups (mainly iron oxides) and not hydroxylated vector minerals (e.g., white mica, chlorite, tourmaline). This work aims to provide a summary of currently available optical satellite sensors and high-level comparison of their applications for critical minerals exploration. In addition to the spatial and spectral resolution, the impact of, for example, signal-to-noise ratio, striping and band width on accurate mineral and element mapping is discussed. For this, case studies are presented that demonstrate the potential use of the respective sensors for different stages of an exploration campaign and also the opportunities for integration with other geoscience data across scales. This abstract was presented to the 13th IEEE GRSS Workshop on Hyperspectral Image and Signal Processing (WHISPERS) November 2023 (https://www.ieee-whispers.com/)