b'AEGC 2023Short abstractson an OcTree mesh, which allows us to refine in the area ofresource potential. Fender Geophysics used a ZZgeo Universal interest without drastically increasing the size of the mesh. We64 resistivity meter to acquire resistivity profiles over 20 of then explore warm-starting and sensitivity-based weighting asthe tailings dams. Resistivity data were post-processed and solutions for recovering more geologically plausible structures. underwent inversion using the Res2Dinv software. Most of the tailings were highly resistive and provided a significant contrast Pre-stack seismic inversion for windfarm applications. to the underlying alluvium. Dam depths estimated from the resistivity survey were up to 5m and agreed well with numerous Esben Dalgaard trenches that had been dug throughout the survey area. The success of the ERT survey over the tailings indicates that the SolidGround technique may be useful for identifying additional tailings The production of offshore windfarms has increased worldwide.deposits that are not easily identified in the LiDAR data.A thorough understanding of the subsurface geotechnical conditions is crucial for the windfarm development as theseApplication of wireline petrophysical data in conditions impacts how the windmill foundations shall bequantitative stress and geotechnical analysis for constructed. Ultra high resolution seismic (UHRS) data isstability risk assessment.key in the process of developing a qualitative geotechnical ground model. Seismic post-stack procedures has previouslyRoland Dashti and Joe Dwyerbeen presented (Vardy, 2015) to obtain quantitative models. UHRS data quality in the pre-stack domain have been throughWSGa great evolution in the recent years (Duarte etal., 2017)Stability assessment of the geological structures is a critical allowing for pre-stack methods to be explored. To exploit thetask in any excavation activity in mining. Conventionally, this full potential of the UHRS data applying AVO inversion foris done based on the geometrical analysis of the geological a quantitative interpretation of geotechnical properties is afeatures using failure models and applying either empirical or promising procedure to get an improved understanding of thelaboratory measured rock strength parameters. In conventional geotechnical ground conditions. Seismic AVO inversion hasanalysis, the rock strength parameters involved are often been an effective procedure for quantitative interpretation inover-conservative and the orientation and magnitude of the the oil and gas industry for several years (Buland etal., 2008). in-situ stresses are often overlooked. In this study, continuous A field case is demonstrated to show how improved seismicdownhole petrophysical and geological data are integrated to processing in the pre-stack domain of UHRS together with AVOevaluate the in-situ stress quantitatively both in magnitude and inversion can aid in forming a quantitative ground model. Basedorientation. The results of this study are then combined with on the UHRS inversion results we present a method to predictstructural interpretations of the geological features observed geotechnical CPT properties like cone resistance, sleeve frictionin borehole televiewer plots to identify the most vulnerable and porewater pressure. These results can help the geotechnicalfeatures to shear failure. These features, which include all planar engineer in solving various problems. The results can aidand sub-planar fractures, faults and bedding contacts are called foundation design and installation calculations. The results cancritically stressed features. The study presents a complementary also help to make a more informed geotechnical field campaignworkflow to assess the failure risk in mining excavation planning. activities. By incorporating continuous in-situ collected data from multiple boreholes, the workflow also provides Geotechnical domaining of the rock mass, which is of significant Mapping historical tailings dams using electricalvalue in any mining geotechnical evaluation.resistivity tomography: A case study from the Tommy Burns mine, North Queensland. Airborne and ground induced polarisation integration: James Daniell 1 Matt Haindl2, Andrew Walsh2 and Andrew Sloot1 New insights for exploration.1 Fender GeophysicsFrancesco Dauti 1 Andrea Viezzoli2, Isla Fernandez3, Jim Royall4 2 Dover Castle Metals and Gianluca Fiandaca1Tommy Burns is a tin/tungsten mine located approximately 1001 The EEM Team for Hydro & eXploration, Department of Earth km south-west of Cairns. The Tommy Burns mine was mined upSciences Ardito Desio, University of Milano, Italy until the mid-1980s with the grade of ore reaching 13% near the2 Emergo srl surface with decreasing Sn and increasing W at depth. LiDAR3 Geognosia sll data from Tommy Burns indicates that there are approximately4 Pan Global Resources Inc20 tailings dams on site ranging in size from 25 000 m2 to 200 m2. Additional dams may also exist but are thought toThe Iberian Pyrite Belt is one of the oldest mining districts still be comparatively old and eroded and therefore not easilyin productions in the world. It hosts the largest concentration identified in the LiDAR data. Sand tailings from the Tommyof massive sulphide deposits worldwide and still presents a Burns mine are known to contain significant concentrations ofhuge mineral potential. As consequence, in the last two years tin. Accurate mapping of the depth and extent of the tailingsthe exploration in the region has increased dramatically also dams could be used to inform resource estimates and lead toin order to supply the raw materials request for the European the possible future reprocessing of these materials. green energy transition. Despite all the work carried out so far in the region it remains severely underexplored often Dover Castle Metals contracted Fender Geophysics torequiring detailed knowledge for the large variability of physical undertake an Electrical Resistivity Tomography (ERT) surveyproperties associated to the mineralisation. As consequence, of the tailings dams to measure their depth and assess theirfrom a geophysical point of view, the general characteristics its FEBRUARY 2023 PREVIEW 90'