GSWA has responded to the COVID-19 pandemic by reprioritising its 2020–21 work program, to aid economic recovery and stimulate the exploration industry. Our response includes a program of webinars to help continue to support Western Australia’s explorers.
Please register in advance via the links below. Recordings of previous webinars are available below.
Dr Sara Jakica, Senior Geologist - Mapping Through Cover 29 October 2021
In predominantly arid Western Australia, paleochannels contain sand-dominated intervals that host water that is of potential interest to farmers, explorers and indigenous people. In many cases, the depth of the paleochannel marks the depth of cover above potentially prospective bedrock. The Cenozoic-era Yangibana paleochannel, composed dominantly of sands and clays, is incised into the Proterozoic granitic basement of the Gascoyne Province. This study demonstrates how the integration of different geophysical methods can improve the currently available paleochannel maps of Western Australia. The methods used in this study add depth information to the paleochannel geometry and increase its resolution.
Angela Riganti, Content Manager 24 September 2021
So-called ‘scientific gentlemen’ were poorly regarded in the early days of the Colony of Western Australia. Their role in the discovery of gold in the young Colony was eventually recognized, and so the Geological Survey of Western Australia (GSWA) was established in 1888. We will explore the captivating history and events that contributed to the founding of one of Western Australia’s oldest institutions. Come along as we take a look at some of the significant milestones achieved in the GSWA’s 133-year-long history.
Simon Johnson, Director Regional Geoscience 30 July 2021
The Geological Survey of Western Australia (GSWA) reprioritized its 2020–21 work program due to the impact of travel and operational restrictions imposed by the COVID-19 pandemic. By using its extensive geoscience datasets, GSWA’s Accelerated Geoscience Program (AGP) has delivered over 100 new interpretive datasets across all areas of geoscience in key regions of the State, as well as increasing accessibility and searchability to key State exploration databases. These products were designed to accelerate our understanding of the regions’ geology, mineral and energy prospectivity, to open up new areas that were previously considered unprospective, and to stimulate the exploration industry.
Oxygen isotopes trace the origins of Earth’s earliest continental crust
Yongjun Lu, Senior Geochronologist Isotope Acquisition 25 June 2021
How continents formed is vigorously debated in the Earth Science community. Although geologists know that water was an essential ingredient for continent formation, many have proposed this water would have come from the Earth’s surface via subduction zones, as on the modern Earth. However, new research led by the Geological Survey of Western Australia in collaboration with Curtin University, The University of Western Australia, Geoscience Australia and international specialists, shows that this water could actually have come from the mantle. This suggests that Earth may have once operated very differently than it does today, and contained more primordial water than previously thought. This research has been published in the journal Nature.
Physical property changes and geophysical signatures of mineral systems
Richard Chopping, Manager Geoscience Mapping Through Cover 21 May 2021
The passage of heat and mineralizing fluids to create a mineral system change the mineralogy of the rocks they interact with. This not only produces both the ore and the distal mineralogical changes characteristic of the system but, in turn, affects the physical properties of those rocks. As geophysical responses are the product of the physical properties of the rocks beneath the survey area, the mineralization changes can produce geophysical signatures.
3D structural modelling of the southern Perth Basin
Charmaine Thomas, Senior Geologist/Geophysicist 23 April 2021
A new 3D geological model of the southern Perth Basin including the offshore was released in 2019, and is the culmination of a project reinterpreting stratigraphic horizons and faults in seismic and drillhole data. The study area stretches from the Rockingham area in the north to Augusta in the south, and extends westwards into the offshore portion of the basin including offshore petroleum wells and as far east as the Darling scarp. The seismic interpretation and geomodel capture some important aspects of this part of the basin, including the immense throw on the Darling Fault (> 12 km in places), the deepening of the basin offshore, and the multiple phases of Gondwanan extension and rifting allowing thick packages of sediment to accumulate.
Geoheritage: protecting Western Australia’s rock stars
Dr Sarah Martin, Paleontologist 19 March 2021
Western Australia is endowed with an impressive array of geological and geomorphological features, from the world’s oldest terrestrial materials and oldest evidence for life, through ancient reefs, dinosaur footprints, meteorite impact sites, vast cave systems and spectacular gorges. These sites are an important part of the State’s heritage, being closely intertwined with Western Australia’s rich biological diversity, and human stories and history. Distributed widely across the State and varying greatly in size and scale, sites must be adequately identified and carefully managed to ensure these unique localities are accessible to future generations.
Despite considerable public knowledge of the needs for and mechanisms of biological and cultural conservation, there is far less awareness of geological heritage and conservation. This talk aims to introduce the concept of geoheritage, explain how these sites are identified and managed within the State of Western Australia, and suggest ways in which we can all be involved in protecting WA’s rock stars!
Potential for Neoproterozoic subsalt helium resources in Western Australia
Peter Haines, Basins Custodian 26 February 2021
Lower Neoproterozoic (c. 800 Ma) salt is widespread in the Officer and Amadeus Basins, and possibly the Murraba Basin. Although older preserved salt is known, these occurrences probably represent the oldest basin-scale salt seal in the world. This has implications not only for trapping subsalt hydrocarbons where a subsalt source rock is present, but also for basement-sourced helium. Two subsalt wells in the Northern Territory demonstrate this play type with gas flows containing 6% and 9% He, but both suffered from poor reservoir quality. Similar plays are likely in Western Australia, with good potential for subsalt reservoirs.
Western Australia’s wealth of microbialites
Heidi Allen, Paleontologist 11 December 2020
Western Australia is renowned for its wealth of microbialites, with living and fossil examples in relatively close proximity allowing comparative study. Living microbialites are best known from the World Heritage Area of Shark Bay, but have also been documented from a series of inland lakes including Lakes Thetis and Clifton. Western Australian fossil microbialites span the geological time scale from Paleoarchean to Recent, with the Strelley Pool and Dresser Formation stromatolites perhaps the most notable of these early records.
In this webinar, Paleontologist Heidi Allen will take you on a tour of significant Western Australian microbialite localities and explain how these tiny but mighty microbes helped shape the course of life on our planet.
Waukarlycarly 1 deep stratigraphic drilling
Leon Normore, Senior Geologist 20 November 2020
Following on from the 872 km onshore Kidson Sub-basin seismic survey is the 2680.5 m Waukarlycarly 1 deep stratigraphic well. This stratigraphic drilling provided continuous core from 580 to 2585 m throughout the Canning Basin stratigraphy and into highly weathered pre-Canning basement rocks, before final total depth into fresh, slightly metamorphosed dolomite. Wireline logs and a vertical seismic profile have also been completed for downhole correlation of well to seismic. This project has been funded by Geoscience Australia’s Exploring for the Future initiative and the Geological Survey of Western Australia’s Exploration Incentive Scheme.
A snapshot of the EIS Co-funded Drilling program: Rounds 1 to 17
Dr Charlotte Hall, EIS Coordinator 23 October 2020
After 10 years of the Western Australian Exploration Incentive Scheme Co-funded Drilling program, a short-term study has provided a snapshot of the statistics, results and impact of the program.
From Round 1 in 2009 to June 2019 when Round 19 projects completed drilling, 482 projects had been drilled across the State. Over 8767 drillholes, for a total of 847 km, are now supplying additional geological knowledge to de-risk exploration targeting and assist research. Diamond holes stored in a state core library number 677 and 43% of these holes, regardless of hole length, have been sampled by researchers providing an important add-on value. Thirty-five projects are reported as a reflection of the ‘success’ of the co-funding with several projects now operating, or in mine planning and feasibility stages.
GSWA's 20/21 Accelerated Geoscience Program
Jeff Haworth, Executive Director 2 October 2020
The advent of the COVID-19 pandemic has meant travel restrictions and a subsequent negative impact on exploration in Western Australia. The Geological Survey of Western Australia (GSWA) has therefore had to rethink its program for the 2020–21 financial year, to provide data and information quickly to enable the exploration industry to recover.
A recent Association of Mining and Exploration Companies (AMEC) report showed 72% of explorers had no investment and half the METS Engineering Group (METS) companies had ceased exploration operations. In addition to this, share prices for over half these companies has dropped 25–50%. The GSWA Accelerated Geoscience program will get information quickly to explorers to use and incentivise the METS sector. An increase of $5 million to the Exploration Incentive Scheme for geophysics acquisition will further stimulate the co-funded drilling program. The program will assist the critical minerals sector.
Seismic monitoring in the Wheatbelt
Dr Ruth Murdie, Senior 3D Geophysicist 25 September 2020
Southwest Australia has the highest level of seismicity in the whole of the continent, yet this is not an area where, geologically, we would expect earthquakes. GSWA is installing three new seismic monitoring stations in and around the Wheatbelt in order to better locate the numerous small earthquakes that happen on a regular basis.
Permanent seismic stations operated by Geoscience Australia automatically locate some of the larger of these events, but the sparsity of the national monitoring network means that the locations obtained are very poor. These new stations double the number in the region and should result in better locations, better identification of potential fault lines and seismic hazard.
Au–Cu mineralization at Obelisk, northern Paterson Orogen
Dr Paul Duuring, Senior Geologist 4 September 2020
A project update for a collaborative study with industry that examines the style and controls on Au-Cu mineralization at the Obelisk deposit in the northern Paterson Orogen.