b'AEGC 2021Short abstractsThis outcome points to further airborne data being acquiredelement of several mineral systems. In particular, the data reveal and included in future national grids. Data from airborne surveysconductivity anomalies at lower crustal and lithospheric mantle acquired by non-government organisations that meet size anddepths that show remarkable spatial correlations with major quality criteria will also be considered for inclusion. suture zones and known gold and copper deposits (e.g. Ernest Henry Mine and The Granites gold mine). These correlations 227: Analysis of teleseismic earthquakes on nodalprovide evidence that large-scale, highly conductive features may control the localisation of mineral deposits in these regions. seismic surveys These results also identify regions with similar features in several Dr Steve Hearn 1, Mr Bodee Bignell2, Mr John McMonagle1 andother under-explored areas that may be prospective for minerals.Dr Shaun Strong11 Velseis Pty Ltd 229: Diagenetic controls on the reservoir quality of 2 University of Queensland organic-rich shales of the Mesoproterozoic Velkerri Formation (Beetaloo Basin)In the past few years, nodal sensors have emerged as the default for seismic exploration. These systems record continuously, andDr Claudio Delle Piane 1, Mr Colin MacRae2, Dr William Rickard3, hence record a range of passive events. Although the sensorDr Vincent Crombez1, Dr Moinudeen Faiz4 and Dr David, N. is designed for higher-frequency events, with appropriateDewhurst4pre-processing it is possible to extract high quality records of teleseismic (distant) earthquakes which are of potential interest1 CSIRO Energy, Deep Earth Imagingin analysis of the crust and upper mantle near the receivers.2 CSIRO Mineral ResourcesAspects of the pre-processing are of interest. Cross-correlations3 Curtin Universityof the earthquake P-wave reveal inter-node time variations4 CSIRO Energywhich resemble statics contours from conventional reflectionDespite more than a decade of sustained production in the processing. Examination of time-distance variation across theU.S., extracting hydrocarbons from unconventional reservoirs nodal array provides an estimate of apparent slowness of theremains an enormous economic, engineering and scientific arriving P-wave. This is useful for confirmation of theoreticalchallenge. This challenge results from these geological travel-time models, and for inferring basement dip. Becausematerials being highly heterogeneous and poorly characterised. of the large channel counts in modern surveys, stacking theEfficiently extracting resources from such reservoirs requires teleseismic event can provide significant improvement ina detailed knowledge of where porosity is located within the signal-to-noise. We have used stacked nodal records to infilltarget units and how this evolved after deposition during between recordings made at permanent seismographs insediment burial and thermal maturation, in order to predict Queensland. Relative travel-time residuals are of order 1-2 s.rock property distributions across sedimentary basins and the Teleseisms arriving from different azimuths produce conflictingexpected response to reservoir stimulation.relative-residual patterns. However, ray-path back projection to upper-mantle depths reveals coherent delay patterns. TheThis contribution focuses on the organic rich intervals of the observations would be consistent with velocity variationsprospective Velkerri Formation from the Beetaloo Sub-basin of order 10% occurring in the depth zone 200-300km. This(Northern Territory), part of the greater McArthur Basin. Due to supports lateral variation in the degree of development of antheir age (Proterozoic, ca. 1.3-1.4 Ga), burial history and proximity upper-mantle low-velocity zone, with low velocities resultingto faults and magmatic intrusions, the organic-rich units from increased temperature and partial melting. currently targeted as potential hydrocarbon reservoirs can be locally affected by diagenetic geochemical alteration that cannot be predicted based on our understanding of more modern 228: Lithospheric resistivity structures and mineralanalogues. Specifically, we show how intervals of intense prospectivity from AusLAMP data in northern Australia diagenetic quartz cementation are widespread throughout the Beetaloo Basin and preferentially affect the organic-rich intervals Mr Jingming Daun of the Velkerri Formation. Quartz cementation manifests as a Magnetotellurics (MT) data allow geoscientists to investigatepervasive nano-crystalline matrix interspersed with clays and is the link between mineralisation and lithospheric-scale featuresinferred to have positive effects on reservoir quality properties and processes. Given the importance of these data, Geosciencelike stiffness and potential for porosity preservation.Australia, state/territory geological surveys and academia haveThis presentation will focus on the quantitative characterization acquired long-period MT data across the Australian continentof quartz cement via the integration of micro and nano-structural under the Australian Lithospheric Architecture Magnetotelluricanalysis, geochemical and petrophysical logging as well as Project (AusLAMP). We use AusLAMP data in northern Australiasequence stratigraphy, to discuss our ability to predict diagenetic to demonstrate the power of the MT method as a mappingeffects on the bulk physical properties of the sediments.tool for lithospheric-scale features that aids in identifying prospective areas for mineral exploration undercover.230: Deciphering the building blocks of the eastern AusLAMP data that were collected in northern AustraliaNorth Australia Cratonunder Geoscience Australias Exploring for the Future (EFTF) programme cross many under-explored and covered regions.Dr Karen Connors 1, Dr Janelle Simpson2 and Mr Dominic Brown3We utilise AusLAMP data as a first-order reconnaissance survey to resolve large-scale lithospheric architectures. The highly1 PESAconductive structures imaged by MT data map the pathways2 ASEGof large-scale palaeo-fluid migration, which is an important3 Geological Survey of Queensland101 PREVIEW AUGUST 2021'