Geoscience Australia and the CO2CRC have constructed a greenhouse gas controlled release facility at an experimental agricultural station maintained by CSIRO Plant Industry at Ginninderra, Canberra. The facility is designed to simulate surface emissions of CO2 (and other greenhouse gases) from the soil into the atmosphere. CO2 is injected into the soil is via a 120m long slotted HDPE pipe installed horizontally 2m underground. This is fitted with a straddle packer system to partition the well into six CO2 injection chambers with each chamber connected to its own CO2 injection line. CO2 was injected into 5 of the chambers during the first sub-surface release experiment (March - May 2012) and the total daily injection rate was 100 kg/d. A krypton tracer was injected into one of the 5 chambers at a rate of 10 mL/min. Monitoring methods trialled at the site include eddy covariance, atmospheric tomography using a wireless networked array of solar powered CO2 stations, soil flux, soil gas, frequency-domain electromagnetics (FDEM), soil community DNA analysis, and krypton tracer studies (soil gas and air). A summary of the findings will be presented. Paper presented at the 2012 CO2CRC Research Symposium, Sunshine Beach, 27-29 November 2012.

As a results of representations made to the Bureau of Mineral Resources by the Australian Aluminium Production Commission during 1948 a brief examination was made in July, 1949, of the area known as Sogeri Plateau which is situated some 24 miles east-north-east of Port Moresby. The object of the inspection was to determine whether any bauxitic laterite was present on the plateau and if so to obtain samples for chemical determination of alumina soluble in caustic soda solution, that is, alumina extractable by the Bayer process. Three car traverses of the area were made - one along the Sogeri-Uberi road, one along the Sogeri-Subitana road and one along the Sogeri-Eilogo road. Two grab samples were collected and sent for analysis. The findings of the examination of the area and the results of the chemical analyses are described in this report.

Soil is a common evidence type used in forensic and intelligence operations. Where soil composition databases are lacking or inadequate, we propose to use publicly available soil attribute rasters to reduce forensic search areas. Soil attribute rasters, which have recently become widely available at high spatial resolutions, typically three arc-seconds (~90 m), are predictive models of the distribution of soil properties (with confidence limits) derived from data mining the inter-relationships between these properties and several environmental covariates. Each soil attribute raster is searched for pixels that satisfy the compositional conditions of the evidentiary soil sample (target value ± confidence limits). We show through an example that the search area for an evidentiary soil sample can be reduced to <10% of the original investigation area. This Predictive Soil Provenancing (PSP) approach is a transparent, reproducible and objective method of efficiently and effectively reducing the likely provenance area of forensic soil samples. <b>Citation:</b> de Caritat, P., Simpson, T. and Woods, B. (2019), Predictive Soil Provenancing (PSP): An Innovative Forensic Soil Provenance Analysis Tool. <i>J Forensic Sci</i>, 64: 1359-1369. https://doi.org/10.1111/1556-4029.14060

We describe a model to predict soil-regolith thickness in a 128,000 ha study area in the central Mt Lofty Ranges in South Australia. The term soil-regolith includes the A, B, and C soil horizons to the lower boundary of the highly weathered bedrock zone (R horizon). The thickness of the soil-regolith has a major control on water holding capacity for plant growth and movement of water through the landscape, and as such, it is important in hydropedological modelling and in evaluating land suitability, e.g. for forestry and agriculture. Thickness estimates also have direct application in mineral exploration and seismic risk assessment. Geology and landscape evolution within the area is complex, reflecting the variable nature of bedrock materials, and the partial preservation of deeply weathered profiles as a consequence of weathering processes dating to the Cenozoic, or possibly older. These characteristics, together with strong climatic gradients across the area, make the study area an ideal location to understand the environmental and landscape evolution controls on weathering depth. The area also features weathered landscape analogues to many parts of southern Australia. We use a digital soil mapping piecewise linear decision tree approach to develop the model to predict soil-regolith thickness. This model is based on relationships established between 714 soil-regolith thickness measurements and 28 environmental covariates (e.g. rainfall, slope, gamma-ray spectrometry). The results establish a correlation R2 of 0.64, based on a 75:25% training:test data split. These results are encouraging, and are a significant advance over soil depth mapping by traditional soil-landscape mapping methods.

The National Geochemical Survey of Australia (NGSA) provides the first national coverage of multi-element chemistry at a continental scale. The NGSA data is an important complement to other national-scale geological and geophysical datasets, particularly the Radiometric Map of Australia. The Radiometric Map of Australia shows potassium (K) measured directly from gamma-rays emitted when 40K decays to argon (40Ar), whereas thorium (Th) and uranium (U) do not emit gamma-rays. Instead, their abundances are inferred indirectly by measuring gamma-ray emissions associated with parent radionuclides (thallium-208 for Th, and bismuth-214 for U) within their radioactive decay chains. Airborne-derived grids provide a continuous prediction of these radioelements across the Australian landscape. In contrast, the NGSA data provide a series of precise single point geochemical measurements of surface (0-10 cm) and near-surface (~60-80 cm depth) unconsolidated catchment outlet sediments.

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.

From 2007 to 2009, the National Geochemical Survey of Australia (NGSA) project collected sediment samples from 1315 sites located in 1186 catchments (~10 % of which were sampled in duplicate) from across Australia. Overbank sediments were chosen as sampling media, with a near-surface sample (Top Outlet Sediment, TOS, from 0-10 cm below the surface) and a bottom sample (Bottom Outlet Sediment, BOS, ~10 cm interval between approximately 60-80 cm below the surface) being collected. The sample sites were selected to be near outlets or spill points of large catchments, so that overbank sediments there could reasonably be assumed to represent well-mixed, fine-grained composite samples of all major rock and soil types present in the catchment. Sample sites and their corresponding sediment samples were subjected to a detailed description and the determination of bulk parameters in the field (texture, moist and dry colour, field pH). This is complemented by a series of laboratory measurements and analyses reported elsewhere. This report documents the complete field dataset and discusses the pH and soil colour data that were collected in the field. At the time of writing, field pH and colour are the only datasets available for all sites. Maps are presented showing the spatial distribution of these data in both TOS and BOS samples. These data will be the basis of further interpretative work.

Global-scale mapping of surface mineralogy is now becoming possible using remote hyperspectral sensing technologies. Global-scale mineral maps have now been generated for Mars using thermal infrared hyperspectral data collected from the Mars-orbiting Thermal Emission Spectrometer (TES- http://jmars.asu.edu/data/), including maps of feldspar, pyroxene, olivine and quartz contents. Other mineral maps of Mars are now being assembled using the recently launched Compact Reconnaissance Imaging Spectrometer (CRISM - http://crism.jhuapl.edu/), including sulphates, kaolinite, illite/muscovite, chlorites, carbonate and water (www.lpi.usra.edu/meetings/7thmars2007/pdf/3270.pdf). In contrast, even though mapping the mineralogy of the Earth's land surface can improve understanding and management of Earth's resources, including: - monitoring of soils (acid sulphate soils, salinity, soils loss and soil carbon); - better characterisation of regolith materials (e.g. transported versus in situ); - discovery of new mineral deposits using alteration vectors; and - more accurate environmental assessments during resource exploitation (baseline mapping, monitoring and closure)

Soil is a ubiquitous material at the Earth's surface with potential to be a useful evidence class in forensic and intelligence applications. Compositional data from a soil survey over North Canberra, Australian Capital Territory, are used to develop and test an empirical soil provenancing method. Mineralogical data from Fourier Transform InfraRed spectroscopy (FTIR) and geochemical data from X-Ray Fluorescence (XRF; for total major oxides) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS; for both total and aqua regia-soluble trace elements) are obtained from the survey's 268 topsoil samples (0–5 cm depth; 1 sample per km2). The simultaneous provenancing approach is underpinned by (i) the calculation of Spearman's correlation coefficients (rS) between an evidentiary sample and all the samples in the database for all variables generated by each analytical method; and (ii) the preparation of an interpolated raster grid of rS for each evidentiary sample and method resulting in a series of provenance rasters (“heat maps”). The simultaneous provenancing method is tested on the North Canberra soil survey with three “blind” samples representing simulated evidentiary samples. Performance metrics of precision and accuracy indicate that the FTIR (mineralogy) and XRF (geochemistry) analytical methods offer the most precise and accurate provenance predictions. Maximizing the number of analytes/analytical techniques is advantageous in soil provenancing. Despite acknowledged limitations, it is concluded that the empirical soil provenancing approach can play an important role in forensic and intelligence applications. <b>Citation:</b> de Caritat, P, Woods, B, Simpson, T, Nichols, C, Hoogenboom, L, Ilheo, A, et al. Forensic soil provenancing in an urban/suburban setting: A simultaneous multivariate approach. <i>J Forensic Sci</i>. 2022; 67: 927–935. https://doi.org/10.1111/1556-4029.14967

A shallow vertical CO2 injection test was conducted over a 21 day period at the Ginninderra Controlled Release Facility in May 2011. The objective of this test was to determine the extent of lateral CO2 dispersion, breakthrough times and permeability of the soil present at the Ginninderra site. The facility is located in Canberra on the CSIRO agricultural Ginninderra Experiment Station. A 2.15m deep, 15cm stainless steel screened, soil gas sampling well was installed at the site and this was used as the CO2 injection well. The CO2 flow rate was 1.6 L/min (STP). CO2 soil effluxes (respiration and seepage) were measured continuously using a LICOR LI-8100A Automated Soil CO2 Flux System equipped with 5 accumulation chambers spaced 1m apart in a radial pattern from the injection well. These measurements were supplemented with CO2 flux spot measurements using a WestSystems portable fluxmeter. Breakthrough at 1m from the injection point occurred within 6 hrs of injection, 32hrs at 2m and after almost 5 days at 3m. The average steady state CO2 efflux was 85 ?mol/m2/s at 1m, 15 ?mol/m2/s at 2m and 5.0 ?mol/m2/s at 3m. The average background CO2 soil respiration efflux was 1.1 - 0.6 ?mol/m2/s. Under windy conditions, higher soil CO2 efflux could be expected due to pressure pumping but this is contrary to the observed results. Prolonged windy periods led to a reduction in the CO2 efflux, up to 30% lower than the typical steady state value.