Product catalogue
Lithospheric architecture and mantle metasomatism linked to iron oxide Cu-Au ore-forming systems: multidisciplinary evidence from the Olympic Dam region, South Australia
The role of lithospheric architecture and the mantle in the genesis of iron oxide copper-gold (IOCG) deposits is controversial. Using the example of the Precambrian Gawler Craton (South Australia), which hosts the giant Olympic Dam IOCG deposit, we integrate recently acquired geophysical data (passive seismic tomography, magnetotellurics) with geological and geochemical data to develop a new interpretation of the lithospheric setting of these deposits. Spatially, IOCG deposits are located above the margin of a mantle lithospheric zone with anomalously high electrical conductivities (resistivity <10 ohm.m, top at ~100-150 km depth), low seismic shear-wave velocities (horizontal component, Vsh <4.6 km/s), and unusually high ratios of compressional- to shear-wave velocities (Vp/Vsh>1.80). The high conductivity cannot be explained by water-bearing olivine-rich rock alone. Relatively fertile and metasomatised peridotitic mantle with additional high-Vp/Vs phases, e.g., clinohumite, hydrous garnet and/or phlogopite, could explain the anomalous velocity and conductivity. The top of this high-Vp/Vsh zone marks a mid-lithospheric discontinuity at ~100-130 km depth that is interpreted to reflect locally orthopyroxene-rich mantle. A sub-Moho zone with high Vp/Vsh at ~40-80 km depth correlates spatially with primitive Nd isotope signatures and arc-related ~1620-1610 Ma magmatism, and is interpreted as the eclogitic root of a magmatic arc. Mafic volcanics contemporaneous with ~1590 Ma IOCG mineralisation have geochemistry suggesting derivation from subduction-modified lithospheric mantle. We suggest that Olympic Dam formed inboard of a continental margin in a post-subduction setting, related to foundering and partial melting of previously refertilised and metasomatised lithospheric mantle. Deposits formed during the switch from compression to extension, following delamination-related uplift and exhumation.
Simple
Identification info
- Date (Creation)
- 2018-07-17T10:00:00
- Date (Publication)
- 2019-11-07T01:54:27
- Citation identifier
- Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/121963
- Cited responsible party
-
Role Organisation / Individual Name Details Author Skirrow, R.G.
Co-author van der Wielen, S.E.
Co-author Champion, D.C.
Co-author Czarnota, K.
Co-author Thiel, S.
- Status
- Accepted
- Point of contact
-
Role Organisation / Individual Name Details Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Point of contact Skirrow, R.G.
Resource provider Resources Division
- Spatial representation type
- Topic category
-
- Geoscientific information
Extent
Extent
))
- Maintenance and update frequency
- As needed
- Keywords
-
-
lithospheric architecture
-
- theme.ANZRC Fields of Research.rdf
-
-
EARTH SCIENCES
-
- Keywords
-
-
Gawler Craton
-
- Keywords
-
-
Olympic Dam deposit
-
- Keywords
-
-
IOCG deposits
-
- Keywords
-
-
mantle metasomatism
-
- Keywords
-
-
tectonic setting
-
- Keywords
-
-
Published_External
-
Resource constraints
- Title
-
Creative Commons Attribution 4.0 International Licence
- Alternate title
-
CC-BY
- Edition
-
4.0
- Access constraints
- License
- Use constraints
- License
Resource constraints
- Title
-
Australian Government Security ClassificationSystem
- Edition date
- 2018-11-01T00:00:00
- Classification
- Unclassified
- Language
- English
- Character encoding
- UTF8
Distribution Information
- Distributor contact
-
Role Organisation / Individual Name Details Distributor Commonwealth of Australia (Geoscience Australia)
Voice
- OnLine resource
-
Link to article
Link to article
- Distribution format
-
-
html
-
Resource lineage
- Statement
-
Not supplied
- Hierarchy level
- Document
Metadata constraints
- Title
-
Australian Government Security ClassificationSystem
- Edition date
- 2018-11-01T00:00:00
- Classification
- Unclassified
Metadata
- Metadata identifier
-
urn:uuid/a04f16e4-1a37-404b-8fd9-b673dff2235b
- Title
-
GeoNetwork UUID
- Language
- English
- Character encoding
- UTF8
- Contact
-
Role Organisation / Individual Name Details Point of contact Commonwealth of Australia (Geoscience Australia)
Voice Point of contact Skirrow, R.G.
Type of resource
- Resource scope
- Document
- Name
-
Geochemistry, Geophysics, Geosystems
Alternative metadata reference
- Title
-
Geoscience Australia - short identifier for metadata record with
uuid
- Citation identifier
- eCatId/121963
- Date info (Creation)
- 2018-05-04T03:37:56
- Date info (Revision)
- 2018-05-04T03:38:12
Metadata standard
- Title
-
AU/NZS ISO 19115-1:2014
Metadata standard
- Title
-
ISO 19115-1:2014
Metadata standard
- Title
-
ISO 19115-3
- Title
-
Geoscience Australia Community Metadata Profile of ISO 19115-1:2014
- Edition
-
Version 2.0, September 2018
- Citation identifier
- https://pid.geoscience.gov.au/dataset/ga/122551