Authors / CoAuthors
Haynes, M. | Afonso, J.C.
Abstract
<div>Lithospheric structure and composition have direct relevance for our understanding of mineral prospectivity. Aspects of the lithosphere can be imaged using geophysical inversion or analysed from exhumed samples at the surface of the Earth, but it is a challenge to ensure consistency between competing models and datasets. The LitMod platform provides a probabilistic inversion framework that uses geology as the fabric to unify multiple geophysical techniques and incorporates a priori geochemical information. Here, we present results from the application of LitMod to the Australian continent. The rasters summarise the results and performance of a Markov-chain Monte Carlo sampling from the posterior model space. Release KY22 is developed using the primary-mode Rayleigh phase velocity grids of Yoshizawa (2014).</div><div><br></div><div>Geoscience Australia's Exploring for the Future program provides precompetitive information to inform decision-making by government, community and industry on the sustainable development of Australia's mineral, energy and groundwater resources. By gathering, analysing and interpreting new and existing precompetitive geoscience data and knowledge, we are building a national picture of Australia's geology and resource potential. This leads to a strong economy, resilient society and sustainable environment for the benefit of all Australians. This includes supporting Australia's transition to a low emissions economy, strong resources and agriculture sectors, and economic opportunities and social benefits for Australia's regional and remote communities. The Exploring for the Future program, which commenced in 2016, is an eight year, $225m investment by the Australian Government.</div>
Product Type
dataset
eCat Id
147315
Contact for the resource
Resource provider
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Point of contact
Digital Object Identifier
Keywords
- ( Project )
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- EFTF – Exploring for the Future
- ( Project )
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- Lithospheric Geophysics
- ( Project )
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- LitMod
- ( Project )
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- Australia's Resources Framework
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- Lithospheric mantle
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- Markov-chain Monte Carlo
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- Bayesian
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- Peroditite
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- Joint inversion
- theme.ANZRC Fields of Research.rdf
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- Inorganic geochemistryIgneous and metamorphic petrologyStructural geology and tectonicsGeothermics and radiometricsSeismology and seismic exploration
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- Published_External
Publication Date
2023-10-19T23:00:06
Creation Date
Security Constraints
Legal Constraints
Status
completed
Purpose
A web service of raster datasets covering the Australian continent. The rasters summarise the results and performance of a Markov-chain Monte Carlo sampling from the posterior model space. Release KY22 is developed using the primary-mode Rayleigh phase velocity grids of Yoshizawa (2014; "Radially anisotropic 3-D shear wave structure of the Australian lithosphere and asthenosphere from multi-mode surface waves").
Maintenance Information
notPlanned
Topic Category
geoscientificInformation
Series Information
Lineage
<div>The inversion is based on Markov chain Monte Carlo sampling of major oxide compositions within the lithospheric mantle (Al2O3, CaO, FeO, and MgO). Coupled with temperature and pressure profiles, Gibbs free-energy minimisation (e.g. Connolly, 2009) allows estimation of the dominant mineral phases and, subsequently, the forward physical response. The LitMod inversion platform was used to perform a joint inversion of the following observed data: elevation (Whiteway, 2009), Rayleigh-wave phase velocities (Yoshizawa, 2014), surface heat flow (International Heat Flow Commission, 2021), and long-wavelength geoid anomalies (Afonso et al., 2019). The parameterisation consists of 1D vertical columns across the Australian continent, with 1° lateral grid. The crust was divided into three layers: sediments, upper crust and lower crust. As a starting model, the thicknesses of sedimentary sequences were estimated using the Phanerozoic OZ SEEBASE dataset (Frogtech, 2005), and crustal thicknesses were taken from AusMoho2012 (Salmon et al., 2013). Similarly, the lower crust was assumed to comprise half the total crustal thickness, to a maximum of 15 km. Seismic wave speeds and density within the crust were initially set from AuSREM (Salmon et al., 2012). To help ensure that deep mantle structures are not mapped into the lithospheric mantle, we use the GyPSuM reference model (Simmons et al., 2010) to assign lower mantle seismic wave speed and density profiles.</div>
Parent Information
Extents
[-46, -9, 111, 155]
Reference System
WGS 84 / geographic 2D (EPSG: 4326)
Spatial Resolution
Service Information
Associations
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