The Cahill Formation - host to uranium deposits in the Alligator Rivers Uranium Field, Australia

All the uranium deposits of the Alligator Rivers Uranium Field of Australia, which between them contain a quarter of the worlds reasonably assured uranium resources, are strata-bound within the Cahill Formation. Three of the four economic deposits are more or less conformable within a lower member near the base of the formation, which contains carbonate and carbonaceous rocks. The formation forms a poorly exposed but continuous folded belt, 5 km or more wide, over an area of about 15 000 square kilometres. Exposure is sparse, the rocks are generally deeply weathered, and knowledge of the stratigraphy of the unit is based largely on the results of shallow stratigraphic drilling. Quartzo-feldspathic and micaceous metasediments are the dominant rock types in the Cahill Formation as a whole, and they have been metamorphosed to the amphibolite grade (staurolite-almandine subfacies). The unit appears to unconformably overlie the Archaean-Lower Proterozoic granite-gneiss-migmatite Nanambu Complex and the Lower Proterozoic psammo-pelitic Mount Partridge Formation, and is overlain, in places unconformably, by the Fisher Creek Siltstone. It grades into the migmatite-gneiss-granite terrain of the Nimbuwah Complex in the north-east. The formation is a facies equivalent of the Koolpin Formation (host to uranium mineralization in the South Alligator Valley uranium field) to the south, and, in places, was separated from it during deposition by a basement high of Mount Partridge Formation. The carbonate-carbonaceous sequence was probably deposited under shallow near-shore shelf conditions, along with considerable admixed terrigenous material. The upper part of the formation represents a period of transgression over the shelf. Uranium was concentrated under reducing conditions which developed locally in many places within the carbonate shelf. Subsequent concentration and reconstitution took place a number of times, the main period being during 1800 m.y. regional metamorphism and deformation. Mobilization of uranium away from the carbonate-carbonaceous sequence took place only under high temperature and pressure conditions such as those attending formation of the Nimbuwah Complex, where the metal was relocated in favourable low pressure structures.

Simple

Identification info

Date (Publication)
1976-01-01T00:00:00
Citation identifier
Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/80899

Cited responsible party
Role Organisation / Individual Name Details
Publisher

Bureau of Mineral Resources, Geology and Geophysics

 Canberra
Author

Needham, R.S.

 1
Author

Stuart-Smith, P.G.

 2
Name

BMR Journal of Australian Geology and Geophysics

Issue identification

1:4:321-333

Point of contact
Role Organisation / Individual Name Details
Custodian

Corp
Owner

Commonwealth of Australia (Geoscience Australia)
Custodian

Commonwealth of Australia (Geoscience Australia)

 Voice
Topic category
  • Geoscientific information

Extent

N
S
E
W


Maintenance and update frequency
Unknown

Resource format

Title

Product data repository: Various Formats

Website

Data Store directory containing the digital product files

Data Store directory containing one or more files, possibly in a variety of formats, accessible to Geoscience Australia staff only for internal purposes

Keywords

  • GA Publication

  • Journal

Keywords

  • NT

Australian and New Zealand Standard Research Classification (ANZSRC)

  • Earth Sciences

Keywords

  • Published_External

Resource constraints

Title

Creative Commons Attribution 4.0 International Licence

Alternate title

CC-BY

Edition

4.0

Website

http://creativecommons.org/licenses/

Access constraints
License
Use constraints
License

Resource constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

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

Journal article (pdf)

Journal article (pdf)

Distribution format

  • pdf

Resource lineage

Statement

Unknown

Hierarchy level
Non geographic dataset
Other

GA Publication

Description

Source data not available.

Metadata constraints

Title

Australian Government Security ClassificationSystem

Edition date
2018-11-01T00:00:00
Website

https://www.protectivesecurity.gov.au/Pages/default.aspx

Classification
Unclassified

Metadata

Metadata identifier
urn:uuid/fae9173a-6f60-71e4-e044-00144fdd4fa6

Title

GeoNetwork UUID

Language
English
Character encoding
UTF8
Contact
Role Organisation / Individual Name Details
Point of contact

Commonwealth of Australia (Geoscience Australia)

 Voice

Type of resource

Resource scope
Document
Name

AGSO BMR Journal

Alternative metadata reference

Title

Geoscience Australia - short identifier for metadata record with

uuid

Citation identifier
eCatId/80899

Metadata linkage

https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/fae9173a-6f60-71e4-e044-00144fdd4fa6

Date info (Revision)
2018-04-20T06:10:23
Date info (Creation)
2014-06-03T00:00:00

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

 
 

Spatial extent

N
S
E
W



Provided by

Access to the portal

Associated resources

Not available