{"title":"Quality control in airborne geophysics","authors":"D. FitzGerald","doi":"10.1080/22020586.2019.12072964","DOIUrl":"https://doi.org/10.1080/22020586.2019.12072964","url":null,"abstract":"Summary Onshore exploration technology continues to evolve with the arrival of new airborne instrumentation systems. Central to this has been the need to also evolve quality control processes that ensure useable signal is being captured during the surveying process, even though the true value add occurs at a later time. Gravity gradiometry is now well established, and able to provide independent mapping detail to wavelengths of less than 400 m. Airborne electromagnetic data is also starting to provide cross-sections that are reflecting actual geology bodies in terms of dips and thicknesses. The quality control (QC) technology applied across the industry is not uniform, and sometimes inappropriate for new datatypes being acquired. Government contract specifications can help. Also improved software tools being generally available and having trained operators, is an emerging requirement. This critical aspect includes fit for purpose geophysical gridding.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82496149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Insights on landscape geochemistry and mineral exploration in the Fraser Range, Albany-Fraser Orogen, Western Australia","authors":"G. Alvarez, W. Salama, Tania Ibrahimi, M. LeGras","doi":"10.1080/22020586.2019.12072979","DOIUrl":"https://doi.org/10.1080/22020586.2019.12072979","url":null,"abstract":"Summary The Albany-Fraser Orogen is an emerging recently opened mineral exploration province in Western Australia due to the recent discoveries of the Tropicana-Havana Au system in 2005, and the Nova-Bollinger Ni-Cu deposit in 2015. Simons Hill is located less than 10 km to the SW of the Nova–Bollinger system in the Albany-Fraser Orogen in Western Australia. This study analysed the nature and distribution of the regolith, and its stratigraphy, weathering and depositional history that have led to a variety of residual and transported regolith types. It aims to expand the understanding of the landscape geochemistry associated with Symons Hill in order to provide insights into mineral exploration techniques in this region. Symons Hill is located on a palaeo-topographical high that did not experience the transgression–regression cycles that affected the Albany–Fraser Region for the last 60My. Hence the Simons Hill stratigraphy lacks the marine geochemical influence which is widespread in the Norseman area. The landscape at Symons Hill evolved in a lacustrine/swamp environment. Poor drainage resulted in an extensive, thin (<30m) and homogeneous fine–grained transported cover that displays the same geochemical footprint as the underlying unweathered basement rocks. This cover includes the thicker palaeochannel sequences at the south of the tenement. Most of the transported cover is <5 m thick. Since this cover is the result of local recycling of weathered outcrops, it is an appropriate sampling medium to assess the geochemical composition of the rock at depth. Even if metal geochemical anomalies were displaced laterally, the source of the anomaly at depth is localised, and is most often located within a few 100s of metres from its source. This is a key element to keep in mind when undertaking mineral exploration in the Albany-Fraser Orogen.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82053624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fraccing onshore Australia 2019","authors":"M. Williamson","doi":"10.1080/22020586.2019.12073013","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073013","url":null,"abstract":"Summary Australia is at last seeing common-sense with some of its key politicians at State level moving to remove barriers to the use of fraccing as an exploration and production technique. The most recent and politically important have been the decisions of Western Australia and the Northern Territory to allow fraccing under controlled conditions and apparently strict regulations. Based on publicly available material this extended abstract will explore exactly how far those two Governments are prepared to go in 2019 and the best indications of the areas of regulation and the conditions that will be applied. This abstract will not address any political, social, health or cultural issues focusing only on technical scientific matters including some of the environmental aspects.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84215584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MCNP modelling of a neutron generator and its shielding for PGNAA in mineral exploration","authors":"S. Petrović, M. Carson","doi":"10.1080/22020586.2019.12073186","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073186","url":null,"abstract":"Summary This paper present results of Monte Carlo simulations of shielding design against neutron and gamma-rays from a D-D 2.5MeV neutron generator. The generator will be located in a restricted access laboratory at the Department Of Exploration Geophysics at Curtin University. To protect staff and students from radiation we need to calculate shielding characteristics needed to reduce the effective dose, from the generator, to safe limits. Since operation facility is of limited dimensions, shielding needs to be optimised in terms of it thickness and the cost as well. Shielding calculations were made using the MCNP6.1 Monte Carlo code. We were required by Radiological Council of Western Australia to put sufficient shielding to achieve a conservative dose constraint for non-radiation workers of 0.5 mSv per year or 9.6 μSv in a week. The shielding was modelled as a hollow sphere of varying shielding thickness of borated polyethylene (BPE), concrete and lead (Pb). Our goal was to determine thickness of concrete needed to decrease the effective dose below prescribed limits. We already purchased 15cm thick BPE and 2.2mm Pb slabs. As a result, we concluded that 15cm thick concrete shielding will be enough to safely operate neutron generator. Our neutron generator will be one of the main components of our proposed prompt gamma neutron activation (PGNA) logging-while-drilling (LWD) tool. This tool should be able to reliably identify the major elements of rock units, including the presence of metallic ores. The availability of such real-time information should improve almost every stage of mining and mineral processing.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84374025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rift initiation on Australia’s southern margin: insights from the Bremer Sub-basin","authors":"J. Cunneen, A. Buckingham, C. D’Ercole","doi":"10.1080/22020586.2019.12073180","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073180","url":null,"abstract":"Summary The Bremer Sub-basin occupies a unique position on Australia’s south-west margin. It is influenced by two rift events associated with the breakup of Gondwana: rifting along Australia’s western margin in the Early Cretaceous as well as the southern margin rifting in the Late Cretaceous. The basin is underlain by Proterozoic granites, gneisses and sedimentary rocks of the Albany- Fraser Orogen and the structural fabric of the basin is strongly influenced by the basement architecture. Weaknesses along shear zones localised deformation in the early rift phases, resulting in complex structures including ramp-flat faults and associated extensional folds. The western part of the basin contains reactivated NWtrending shear zones in the basement, which are visible onshore in magnetic data and are shown to extend offshore using satellite gravity data. Strike-slip reactivation of these shear zones resulted in isolated deep depocentres and basement highs. In the central and eastern part of the basin, salt diapirs and associated salt withdrawal and expulsion structures were active during rifting and breakup. The salt is likely Proterozoic in age and is tentatively correlated with salt in the Polda Trough, 1500 km east of the Bremer Sub-basin, which has implications for our understanding of the pre-rift architecture of Australia’s southern margin.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87212878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Gong, D. Fell, R. Hunn, R. Bisley, A. Karvelas, Bee Jik Lim
{"title":"Resolving complex velocity and gas absorption features with fullwaveform inversion in the Taranaki Basin, New Zealand","authors":"Y. Gong, D. Fell, R. Hunn, R. Bisley, A. Karvelas, Bee Jik Lim","doi":"10.1080/22020586.2019.12073076","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073076","url":null,"abstract":"Summary The Western Platform multiclient survey is in the Taranaki Basin, offshore New Zealand. Legacy imaging efforts have suffered due to being unable to overcome the presence of multiple geological challenges. A complex shallow overburden across the survey area, in addition to The Cape Egmont Fault Zone, provide a significant challenge to velocity model building. Shallow gas clouds are also prevalent throughout the survey, impacting imaging at the key zones of interest. To address these challenges, full-waveform and common image point tomography were performed to derive a high-resolution velocity model. Q-FWI was used to derive a detailed Q model representing the shallow gas bodies. In this case study, we demonstrate the successful application of diving-wave FWI, Q-FWI, and FWI using reflection energy to resolve a high-resolution velocity and Q model. This detailed model enabled the final imaging performed with Q-Kirchhoff prestack depth migration to compensate for the complex kinematics and gas-related absorption effects observed in the survey.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85114786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Eromanga oil traps – a multi field post-mortem","authors":"K. Martens","doi":"10.1080/22020586.2019.12072945","DOIUrl":"https://doi.org/10.1080/22020586.2019.12072945","url":null,"abstract":"Summary The purpose of this paper is to examine the remaining oil potential of the Eromanga Basin, specifically in the Cooper region. The key factor is the timing of dominant oil charge. If the oil moved after the late compression and anticlinal structures are critical for commercial success, then the potential is low since almost all these features have been identified and drilled. If the oil moved before the late structuring then except for a few mappable paleostructures, the oil must have been trapped stratigraphically. The late structuring role would then tilt or remobilize the oil locally. If this is the case, then the large unexplored areas of the basin with little or no late structure are just as prospective as the explored structural areas. Additionally, even the discovered oil fields may not be fully appraised as the stratigraphic variability in reservoir has not been fully accounted for. The examination method chosen was to map and postmortem a semi-regional 9000 sq km area with 6 anticlines with numerous oil fields, near successes and dry holes. The area also has extensive 3D seismic. It was found that a strong case could be made that all the oil discoveries were stratigraphically trapped and the late structure only rearranged some of the already trapped oil. This conclusion not only upgrades the future exploration potential of the Basin but points the way to a fundamentally different way of mapping and high grading prospects.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91074470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Betts, R. Armit, C. Tiddy, S. Armistead, L. Aillères
{"title":"Tectonic analysis of regional potential field data","authors":"P. Betts, R. Armit, C. Tiddy, S. Armistead, L. Aillères","doi":"10.1080/22020586.2019.12073022","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073022","url":null,"abstract":"Summary This contribution uses several case studies to illustrate how regional aeromagnetic and gravity data is used to undertake tectonic analysis. Regional aeromagnetic and gravity data is a powerful tool for tectonic analysis because it can be interpreted and modelled at different scales, and it is very effective at imaging different crustal levels. The signal in the data can also be linked to geological features and processes, and importantly, it is amenable to structural analysis, which can be used to inform 3D geometry, kinematics, and overprinting relationships. When combined with geological context the data can constrain tectonic settings and evolutions, and importantly provide context for mineral system analysis. We use examples from the IOCG belts of Proterozoic Australia. We present data from the Mount Woods Inlier in the northern Gawler Craton, to this part of the craton is highly extended, resulting the development of a metamorphic core complex. We then illustrate the tectonic setting for IOCG mineralisation in the Curnamona Province, illustrating how structural analysis of the data provides key constraints on tectonic transport direction.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88934442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Scibiorski, D. Peyrot, Simon Christopher Lang, T. Payenberg, A. Charles
{"title":"Kerogen associations and paleoenvironmental interpretation of the Upper Triassic Mungaroo Formation in the Gorgon Area, Northern Carnarvon Basin, Western Australia","authors":"J. Scibiorski, D. Peyrot, Simon Christopher Lang, T. Payenberg, A. Charles","doi":"10.1080/22020586.2019.12073018","DOIUrl":"https://doi.org/10.1080/22020586.2019.12073018","url":null,"abstract":"Summary Kerogen slides were made from 92 core samples selected from the Upper Triassic Mungaroo Formation in four wells in the Gorgon area of the Northern Carnarvon Basin. The slides were examined to investigate relationships between kerogen assemblages and their depositional environments (“depofacies”). Although the assemblages naturally vary and overlap to an extent, each depofacies has a characteristic kerogen assemblage. Moreover, depofacies which are genetically similar tend to have similar assemblages even though they may have been deposited in different parts of the delta. For example, active channels tend to have similar kerogen assemblages (abundant black-opaque particles, few cuticles, sparse palynomorphs) irrespective of whether they are fluvial, crevasse or distributary channels; in this case, it is inferred that the overwhelming factor in the kerogen assemblages is the high energy level of the environment of deposition, and its consequent inhibition of local vegetation and promotion of mechanical degradation of organic particles.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90797288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Queensland Mining Journal analytics: new information from old data","authors":"Cyril Gagnaire, Neil Constantine, Michael Ball","doi":"10.1080/22020586.2019.12072962","DOIUrl":"https://doi.org/10.1080/22020586.2019.12072962","url":null,"abstract":"Summary The Queensland Mining Journal represents a wealth of information relating to mining activities in the state, from 1800 to the present day. This material has been scanned and made available in the public domain as high-quality image files. We have applied Google Vision optical character recognition, parsed the output JSON files through a domain-specific filter and indexed the content for presentation via an analytics dashboard based on mineralogy and which can be filtered by commodity age and location. The dashboard further incorporates mine site information from Queensland’s Digital Exploration (QDEX) Data System allowing prospective miners to drill down into QDEX content based on mineral occurrence, mine status and deposit size. We plan to build on this activity using Elastic Search to improve our association of content from articles to spatial location. This activity supports individuals and mining companies with an interest in Queensland to rapidly identify locations of interest. It offers a pragmatic approach using freely available information to support the Queensland authorities in attracting investment to their region through lowering the barrier in terms of effort level for companies looking to explore in the state. This comes at a time of heightened competition for investment and could ultimately lead to increased exploration activity and success, resulting in brownfield development of historic prospects and mine sites, minimising environmental impact of new exploration and mining yet generating income for the state through local activity and tax revenue on any mineral extraction.","PeriodicalId":8502,"journal":{"name":"ASEG Extended Abstracts","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77422382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}