Product catalogue
Inferred Magnesium Number Maps for the Bulk Lithospheric Mantle Beneath Australia
<div>Raster datasets of inferred magnesium number for the bulk lithospheric mantle across the Australian continent. The magnesium number is an elemental ratio, defined by Mg / (Mg + Fe), which correlates to the relative enrichment or depletion in incompatible elements. Oxide concentrations are inferred in from thermo-chemical inverse modelling of Rayleigh phase velocities, surface heat flow, geoid anomalies, and topography. The magnesium number rasters summarise the results of a Markov-chain Monte Carlo sampling of the posterior model space from an ensemble of plausible candidate models. Model release 'FR23' is developed using primary-mode Rayleigh phase velocity grids adapted from Fishwick & Rawlinson (2012; "3-D structure of the Australian lithosphere from evolving seismic datasets"). Model 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"). All models are products of the Exploring for the Future program.</div>
Simple
Identification info
- Date (Creation)
- 2023-11-25T07:00:00
- Date (Publication)
- 2023-11-29T21:41:12
- Citation identifier
- Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/149092
- Citation identifier
- Digital Object Identifier/https://dx.doi.org/10.26186/149092
- Cited responsible party
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Role Organisation / Individual Name Details Publisher Commonwealth of Australia (Geoscience Australia)
Voice Author Haynes, M.
Internal Contact Author Afonso, J.C.
External Contact
- Purpose
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Maps of inferred magnesium number for the bulk sub-continental lithospheric mantle across Australia. The magnesium number is an elemental ratio, defined by Mg / (Mg + Fe), which correlates to the relative enrichment or depletion in incompatible elements. Oxide concentrations are inferred in these models from inverse modelling of Rayleigh phase velocities, surface heat flow, geoid anomalies, and topography. The inversions assume peridotite lithologies within the lithospheric mantle.
- Status
- Point of contact
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Role Organisation / Individual Name Details Resource provider Minerals, Energy and Groundwater Division
External Contact Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Point of contact Haynes, M.
Internal Contact
- Spatial representation type
- Topic category
-
- Geoscientific information
Extent
))
- Maintenance and update frequency
- Not planned
Resource format
- Title
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Product data repository: Various Formats
- Protocol
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FILE:DATA-DIRECTORY
- Name of the resource
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Data Store directory containing the digital product files
- Description
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Data Store directory containing one or more files, possibly in a variety of formats, accessible to Geoscience Australia staff only for internal purposes
- Project
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EFTF – Exploring for the Future
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- Project
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Australia’s Resources Framework
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- Project
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Lithospheric Geophysics
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- Project
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LitMod
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- Keywords
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Magnesium number
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- Keywords
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Metasomatism
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- Keywords
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SCLM
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- Keywords
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Sub-Continental Lithospheric Mantle
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- Keywords
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Peridotite
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- theme.ANZRC Fields of Research.rdf
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Igneous and metamorphic petrology
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Resource geoscience
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Seismology and seismic exploration
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- Keywords
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Published_External
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Resource constraints
- Title
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Creative Commons Attribution 4.0 International Licence
- Alternate title
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CC-BY
- Edition
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4.0
- Addressee
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Role Organisation / Individual Name Details User Any
- Use constraints
- License
- Use constraints
- Other restrictions
- Other constraints
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© Commonwealth of Australia (Geoscience Australia) & Macquarie University 2023
Resource constraints
- Title
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Australian Government Security Classification System
- Edition date
- 2018-11-01T00:00:00
- Classification
- Unclassified
- Classification system
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Australian Government Security Classification System
Associated resource
- Association Type
- Was derived from
- Title
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Thermo-chemical inversion of the Australian lithospheric mantle (FR23)
- Citation identifier
- 147926
- Citation identifier
- 925a4194-d032-4da3-b727-09a843014388
Associated resource
- Association Type
- Was derived from
- Title
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Thermo-chemical inversion of the Australian lithospheric mantle (KY22)
- Citation identifier
- 147315
- Citation identifier
- 1f32f30e-96a0-40ee-a15d-aa7be49350a2
- Language
- English
- Character encoding
- UTF8
Distribution Information
- Distributor contact
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Role Organisation / Individual Name Details Distributor Commonwealth of Australia (Geoscience Australia)
Voice facsimile
- OnLine resource
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Download Maps (zip) [1.0 MB]
Download Maps (zip) [1.0 MB]
- Distribution format
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tif, jpg, txt, png - zip
- File decompression technique
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unzip
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Resource lineage
- Statement
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<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 (Fishwick & Rawlinson, 2012; 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. The magnesium number maps report an elemental ratio which can be calculated from the published LitMod results according to MgO/40.304 * (MgO/40.304 + FeO/71.844)^(-1).</div>
Reference System Information
- Reference system identifier
- EPSG/WGS 84 / geographic 2D (EPSG: 4326)
Metadata constraints
- Title
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Australian Government Security Classification System
- Edition date
- 2018-11-01T00:00:00
- Classification
- Unclassified
Metadata
- Metadata identifier
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urn:uuid/c4659ea2-fbc8-4045-821f-b8700a6494b4
- Title
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GeoNetwork UUID
- Language
- English
- Character encoding
- UTF8
- Contact
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Role Organisation / Individual Name Details Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Point of contact Haynes, M.
Internal Contact
Type of resource
- Resource scope
- Dataset
Alternative metadata reference
- Title
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Geoscience Australia - short identifier for metadata record with
uuid
- Citation identifier
- eCatId/149092
- Date info (Creation)
- 2023-11-29T21:25:01
- Date info (Revision)
- 2023-11-29T21:25:01
Metadata standard
- Title
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AU/NZS ISO 19115-1:2014
Metadata standard
- Title
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ISO 19115-1:2014
Metadata standard
- Title
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ISO 19115-3
- Title
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Geoscience Australia Community Metadata Profile of ISO 19115-1:2014
- Edition
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Version 2.0, September 2018
- Citation identifier
- http://pid.geoscience.gov.au/dataset/ga/122551