Authors / CoAuthors
Jiang, W. | Duan, J. | Brodie, R.C.
Abstract
As part of Geoscience Australia’s Exploring for the Future Program, Broadband and Audio Magnetotelluric (MT) data were acquired at 131 stations in the East Tennant region, Northern Territory, in 2019. This survey aimed to characterise major crustal structures, to map cover thickness to assist in stratigraphic drill targeting, and to help understand mineral potential in the region. The data package was released in December 2019 (http://dx.doi.org/10.26186/5df80d8615367) and the 3D resistivity model was released in March 2020 (https://pid.geoscience.gov.au/dataset/ga/135011). We applied a probabilistic approach to inverting high-frequency MT data for cover thickness estimation using the 1D Rj-McMCMT code, newly developed in Geoscience Australia. The inversion employs multiple Markov chains in parallel to generate an ensemble of millions of resistivity models that adequately fit the data given the assigned noise levels. The algorithm uses trans-dimensional Markov chain Monte Carlo techniques to solve for a probabilistic resistivity-depth model. Once the ensemble of models is generated, its statistics are analysed to assess the posterior probability distribution of the resistivity at any particular depth, as well as the number of layers and the depths of the interfaces. This stochastic approach gives a thorough exploration of the model space and a more robust estimation of uncertainty than deterministic methods allow. This release package includes the results of probabilistic inversion of Audio Magnetotelluric data at the 131 stations. They can be used to estimate cover thickness for drill site planning, and to map the base of geological basins in the region. Model data files are large, but can be made available on request to clientservices@ga.gov.au.
Product Type
model
eCat Id
144339
Contact for the resource
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Point of contact
Digital Object Identifier
Keywords
- theme.ANZRC Fields of Research.rdf
-
- EARTH SCIENCES
- ( {1} )
-
- HVC_144686
- ( Sub-Topic Category )
-
- Magnetotellurics
- ( Discipline )
-
- Geophysics
- ( Project )
-
- Exploring for the Future
- ( {1} )
-
- Published_External
- ( Project )
-
- East Tennant
Publication Date
2020-09-23T03:33:57
Creation Date
Security Constraints
Legal Constraints
Status
Purpose
Maintenance Information
asNeeded
Topic Category
geoscientificInformation
Series Information
Lineage
East Tennant project is funded by the Exploring for the Future Program.
Parent Information
Extents
[-20.20, -18.60, 135.00, 137.00]
Reference System
Spatial Resolution
Service Information
Associations
Association Type - crossReference
East Tennant Magnetotelluric Survey, Northern Territory, Australia
eCat Identifier - 132016,
UUID - b123934b-9f88-4a01-b88a-e873b09e5116
Association Type - crossReference
Conductivity Model Derived from Magnetotelluric Data in the East Tennant Region, Northern Territory
eCat Identifier - 135011,
UUID - bce5dc4e-db8d-4611-a117-923ce2c9fdef
Source Information