Abstract

Volcanic-related U mineralisation is rare in Australia, with most occurrences restricted to northern Queensland. Deposits associated with volcanic rocks may be very large, as in the case of the Streltsovka Caldera in Russia, and are therefore attractive exploration targets. An assessment of potential for volcanic-related U systems has been undertaken on a continental scale using a GIS-based approach. This has focused on identifying those units or magmatic events which are most favourable for the presence of magmatic-related U systems. Thus, the results do not necessarily identify likely locations of mineralisation, but rather are intended to form the basis for area selection and detailed follow-up work. This map uses surface geology, and therefore no information is given of the potential for these systems undercover. This map applies a mineral systems approach to assessing the potential for volcanic-related U systems, which is translated into mappable geoscientific criteria. The mineral systems model has three components: (1) melt generation; (2) U concentration; and (3) U deposition. Prospectivity criteria for melt generation (1) are the distribution of felsic or alkaline igneous rocks, geochemical criteria indicating high U solubility in the magma (eg., high alkalis or halogens), and rock descriptions suggesting that U is in a form available to leaching by hydrothermal fluids (eg., rocks with a glassy matrix). Uranium concentration (2) is facilitated by fractional crystallisation, which is quantified using Rb/Sr, and exhibits itself in elevated U or high field strength element contents. Uranium deposition (3) is mapped using U2/Th radiometric anomalies. The 'fuzzy logic' method is used to combine the disparate prospectivity criteria developed. The result gives an indication of the potential prospectivity on a scale of 0 to 1. This study confirms the high prospectivity of northern Queensland for volcanic-related U systems. High potential is also indicated in provinces already well-known for U, such as the Pine Creek and Mount Isa regions. Additionally, several areas not currently known for U mineralisation have been identified, including the Gawler Range Volcanics of South Australia and in the Halls Creek region of Western Australia. These potentially represent new districts which may be prospective for volcanic-related U systems. Note that the potential indicated here does not include other 'hybrid-style' systems, which may also have a genetic association with igneous rocks, such as the Olympic Dam IOCG-U deposit.
Google map showing geographic bounding box with values North bound -9.0 East bound 156.0 West bound 110.0 South bound -44.0
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Product Type/Sub Type

dataset - Thematic Map

Constraints

license
Creative Commons Attribution 3.0 Australia Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

2011

Product Type

dataset

Topic Category

geoscientificInformation

Keywords

Thematic Map
mineral exploration
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound
-9.0
East bound
156.0
West bound
110.0
South bound
-44.0

Lineage

Unknown

Digital Transfer Options

onLine

DISTRIBUTION Format

pdf
jpg

Distributor

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

Metadata File Identifier

a05f7892-f972-7506-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

2010-05-19

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
Downloads
For information on acquiring this product,
please contact Geoscience Australia Client Services via:

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