The Layered Geology of Australia web map service is a seamless national coverage of Australia’s surface and subsurface geology. Geology concealed under younger cover units are mapped by effectively removing the overlying stratigraphy (Liu et al., 2015). This dataset is a layered product and comprises five chronostratigraphic time slices: Cenozoic, Mesozoic, Paleozoic, Neoproterozoic, and Pre-Neoproterozoic. As an example, the Mesozoic time slice (or layer) shows Mesozoic age geology that would be present if all Cenozoic units were removed. The Pre-Neoproterozoic time slice shows what would be visible if all Neoproterozoic, Paleozoic, Mesozoic, and Cenozoic units were removed. The Cenozoic time slice layer for the national dataset was extracted from Raymond et al., 2012. Surface Geology of Australia, 1:1 000 000 scale, 2012 edition. Geoscience Australia, Canberra.

An integrated, multi-scale hydrogeophysical, hydrogeochemical and hydrogeological systems approach has been used to map and assess shallow (<100m) aquitards in unconsolidated alluvial sediments beneath the Darling River floodplain. The study integrated data from an airborne electromagnetics (AEM) survey (over an area of 7,500 km2), with targeted ground electrical surveys, borehole lithological and geophysical data (induction, gamma and nuclear magnetic resonance (NMR)), hydrogeological and hydrogeochemical data obtained from a 100 borehole (7.5 km) drilling program. AEM mapping has confirmed the near-ubiquitous presence of a relatively thin (5-10m) lacustrine Blanchetown Clay aquitard overlying the primary Pliocene fluvial aquifer. Mapping has revealed variations in Blanchetown Clay extent and thickness, with a complex sub-surface distribution. Variations in the elevation of the top of the Blanchetown Clay (20-80m AHD) are attributed partly to neotectonics, including warping, discrete fault offsets, and regional tilting. The aquitard properties of the Blanchetown Clay are demonstrated by hydrograph responses in overlying and underlying aquifers, by wetting profiles observed in drillcore, core moisture data, NMR, induction and gamma logging, laboratory permeameter measurements on cores, and hydrogeochemical data. AEM and induction logs indicate, in some areas, a decrease in electrical conductivity at the centre of the clay rich aquitard. Core moisture data and NMR logs of total water collected through the clay aquitard can show reduced water contents in the aquitard centre, although below the water table. These data also indicate that the clay aquitard can be partially saturated both from the top and the bottom. NMR provides good relative measurements of water contents in the aquitards, however, an inter-echo spacing of 2.5 ms in the Javelin tool limited the amount of water detectable in smaller pore spaces, leading to an underestimate of the water content in muds. While further research is required into factors influencing NMR responses, analysis of NMR responses when integrated with AEM signatures, and other hydrogeological and hydrochemical data, has helped identify zones of aquitard leakage and 'seals' for potential managed aquifer recharge (MAR) sites.

A review of mineral exploration trends, activities and discoveries in Australia in 2020

No abstract available

Part of the Kalimantan 1:250 000 Geological/Geophysical mapping series prepared BMR in cooperation with Pusat Penelitian dan Pengembangan Geologi (Indonesia).

No abstract available

Part of the Kalimantan 1:250 000 Geological/Geophysical mapping series prepared BMR in cooperation with Pusat Penelitian dan Pengembangan Geologi (Indonesia).

Surface water availability limits managed aquifer recharge (MAR) opportunities in inland Australia, however new mining and energy developments (e.g. coal seam gas and shale gas) have increased the range of available source waters for MAR. Furthermore, in northern Australia, recent studies have shown that shallow aquifers may not experience seasonal 'fill and spill', and hence have greater potential for enhanced recharge than previously realised. Economic factors generally limit MAR investigations to shallow (<200m depth) groundwater systems near existing infrastructure. However, in the near-surface environment, MAR storage potential lies in shallow palaeo-channel and alluvial fans systems. Sands deposited in marine environments have a more restricted distribution, but generally have more consistent hydraulic properties. Some of the challenges for MAR projects in inland Australia include: 1. There is a general paucity of relevant spatial and temporal hydrogeological data; 2. Hydrogeological and hydrogeochemical processes in Australia's shallow aquifer systems are generally poorly understood at all scales relevant to MAR assessments; 3. Many of Australia's inland depositional landscapes are characterised by fining-upwards sedimentary systems, limiting surface infiltration options; 4. Palaeo-channel systems are difficult investigative targets, with highly variable hydraulic properties; 5. Confining aquitards (lacustrine or marine clays) have a restricted distribution, and are poorly understood; 6. Post-depositional weathering of sedimentary sequences is significant but highly variable, modifying hydraulic and geochemical properties, with implications for aquifer clogging potential; 7. Faults in sediments and geological basement may be MAR targets and/or play a role in recharge, but their distribution and hydraulic properties are poorly understood; 8. Water quality in aquifers (e.g. salinities and trace metals), important for recovery efficiencies, is poorly understood. Overall, there are significant scientific, technical, economic and social challenges to be overcome to develop MAR options in inland Australia. However, a stringent national risk assessment framework greatly assists with guiding the investigative effort required to assess proposed schemes.

No abstract available

No abstract available