Conductivity Model Derived from Magnetotelluric Data in the East Tennant Region, Northern Territory

Authors / CoAuthors

Jiang, W. | Duan, J.

Abstract

<p>The footprint of a mineral system is potentially detectable at a variety of scales, from the ore deposit to the Earth’s crust and lithosphere. In order to map these systems, Geoscience Australia has undertaken a series of integrated studies to identify key regions of mineral potential using new data from the Exploring for the Future program together with legacy datasets. <p>The recently acquired long-period magnetotellurics (MT) data under the national-scale AusLAMP project mapped a lithospheric scale electrical conductivity anomaly to the east of Tennant Creek. This deep anomaly may represent a potential source region for mineral systems in the crust. In order to refine the geometry of this anomaly, high-resolution broadband and audio MT data were acquired at 131 stations in the East Tennant region and were released in Dec 2019 (http://dx.doi.org/10.26186/5df80d8615367). We have used these high-resolution MT data to produce a new 3D conductivity model to investigate crustal architecture and to link to mineral potential. The model revealed two prominent conductors in the resistive host, whose combined responses link to the deeper lithospheric-scale conductivity anomaly mapped in the broader AusLAMP model. The resistivity contrasts coincide with the major faults that have been interpreted from seismic reflection and potential field data. Most importantly, the conductive structures extend from the lower crust to near-surface, strongly suggesting that the major faults are deep penetrating structures that potentially act as pathways for transporting metalliferous fluids to the upper crust where they can form mineral deposits. Given the geological setting, these results suggest that the mineral prospectivity for iron oxide copper-gold deposits is enhanced in the vicinity of the major faults in the region. <p>This release package includes the 3D conductivity model produced using ModEM code in sGrid format and Geo-referenced depth slices in .tif format.

Product Type

model

eCat Id

135011

Contact for the resource

Point of contact

Commonwealth of Australia (Geoscience Australia)
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia

Point of contact

Resource provider

Digital Object Identifier

https://dx.doi.org/10.26186/135011

Keywords

HVC_144686

theme.ANZRC Fields of Research.rdf

EARTH SCIENCES

( Discipline )

geophysics

( Sub-Topic Category )

magnetotellurics

( Theme )

EFTF

( {1} )

Published_External

( Project )

Exploring For The Future

( Project )

East Tennant

Publication Date

2020-03-23T00:03:02

Creation Date

2020-03-12T11:00:00

Security Constraints

Australian Government Security ClassificationSystem

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence

Access - license

Use - license

Status

completed

Purpose

Maintenance Information

asNeeded

Topic Category

geoscientificInformation

Series Information

Lineage

Geoscience Australia has undertaken integrated studies to identify key regions of mineral potential using new data from Exploring for the Future and legacy data. In July and August 2019, broadband and audio MT data were acquired at 131 stations in the East Tennant region. We have used the high resolution MT data to investigate crustal architecture and to link to mineral potential.

Parent Information

Extents

[-20, -18.5, 135.2, 136.8]

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

Probabilistic Inversion of Audio Magnetotelluric Data in the East Tennant region, Northern Territory, Australia