Abstract

Detailed analysis and modeling of regional gravity and magnetic data from the Stuart Shelf around the Olympic Dam iron oxide copper-gold (IOCG) deposit, constrained by geologic observations obtained from deep drill cores, show that the eastern Gawler craton basement at 1.61 to 1.59 Ga consisted of an Archean core with two sequences of successively younger supracrustal rocks stepping out eastward from it. These were overprinted by the tectonothermal Hiltaba event. Forward models of potential-field data show no convincing evidence for the presence of widespread mafic rocks or extensional basin systems developed immediately prior to, or during, IOCG mineralization. The high intrusive level and sill-like geometry of Hiltaba Suite plutons emplaced immediately prior to IOCG mineralization is difficult to explain in terms of a genetic association with a dominantly extensional tectonic setting. Instead, the tectonic setting inferred from the basement architecture during mineralization is one of low-strain shortening, consistent with regional field observations. A case can be made for intrusion of the Hiltaba Suite in localized accommodation zones in an overall orogenic setting. This style of low-strain shortening (<10%) is consistent with maximum rates and volumes of fluid flow in the upper crust, and access of these fluids to a variety of basement rock types to buffer metal-scavenging fluids. This fluid-driving mechanism does not necessitate a role for regional mafic magmatism and volcanism in the formation of IOCG deposits. Modeling of regional gravity and magnetic data is generally applicable to exploration for IOCG systems, and other mineral systems, in covered terranes that have distinctive geophysical signatures resulting from fluid-wall-rock redox geochemical reactions.
Google map showing geographic bounding box with values North bound -29.0 East bound 138.0 West bound 133.0 South bound -34.0
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Product Type/Sub Type

dataset - External Publication - Scientific Journal Paper

Constraints

license
Creative Commons Attribution 3.0 Australia Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

2007

Product Type

dataset

Topic Category

geoscientificInformation

Keywords

External Publication
Scientific Journal Paper
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound
-29.0
East bound
138.0
West bound
133.0
South bound
-34.0

Lineage

Unknown

Digital Transfer Options

onLine

Distributor

Role
distributor
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address

Metadata File Identifier

a05f7892-f9e3-7506-e044-00144fdd4fa6

Metadata Standard Name

ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata

Metadata Standard Version

1.1

Metadata Date Stamp

2010-10-11

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
Related Links
For information on acquiring this product,
please contact the Geoscience Australia Sales Centre via:

fax:
+61 2 6249 9960; or
phone:
1800 800 173 (within Australia);
 
+61 2 6249 9966 (outside Australia).

Please note that support hours are 9 am to 5 pm weekdays