• Product catalogue
  •  
  •  
  •  

Kimberlite and kimberlitic intrusives of southeastern Australia: a review

Fifteen widely separated occurrences of kimberlite and kimberlitic rocks are now known in southeastern Australia. Those that have been satisfactorily dated isotopically give ages ranging from Permian to Late Jurassic. Field relations indicate that all the occurrences post-date the Proterozoic. Location of the kimberlite intrusions appears to be related to a number of general, structural factors such as the presence of folds, faults and lineaments. Most intrusives are located in belts of present-day seismic activity. The kimberlitic intrusions of New South Wales and Victoria are also associated with a broad zone of epeirogenic uplift, and coincide with the mean migration path of a postulated Cainozoic hot-spot. A number of these features are younger than the age of kimberlitic intrusion, and any causal relationships are unclear. The classification of these generally altered rocks as "kimberlitic" is partly based on their mode of emplacement, and particularly on the presence of crust/mantle inclusions. Compared to African kimberlitic magmas, the southeastern Australian examples have lower incompatible element contents. These differences are interpreted as representing slightly greater degrees of partial melting of a four-phase Iherzolite assemblage at shallower depths than typical African kimberlite magma. Projections of chemical data onto planes within the CaO-MgO-Al2O3-SiO2 system, and comparisons with experimental data, suggest that the magmas were generated at about 65 km depth. Observed fractionation trends of the kimberlitic magma compositions are consistent with minor olivine, and possibly orthopyroxene, fractionation. Upper-mantle nodules in some of the intrusives include spinel, garnet-spinel, and garnet Iherzolite; rare griquaite nodules are found in one pipe at Jugiong. Crustal nodules include garnet clinopyroxenite, eclogite, websterite, and felsic granulite. Most of the mafic crustal nodules are of basaltic composition, and may represent slightly altered, high-pressure, metamorphic equivalents of erupted basalt types, as well as cumulates from basalt magma. None of the salic nodules correspond to the type of source or restite hypothetically involved in granite genesis. P-T estimates for the nodule assemblages give a maximum source of ~ 70 km, and temperatures of ~ 1240°C. They also indicate unusually high geotherms at the time of pipe generation, and the calculated geotherms all exceed the estimated mean oceanic geotherm. The abnormally high geothermal gradient implied by most of these data intersects the graphite-diamond stability curve at considerably higher temperatures and pressures than those indicated by the nodules. If the P-T conditions indicated by these calculations represent a steady-state rather than a transient geotherm, then it is unlikely that diamondiferous kimberlites of Permian or younger age exist in most of southeastern Australia. An exception is the Eurelia (South Australia) province, where the rocks are considered on other evidence to have been formed at depths > 125 km. The combined results of seismic and kimberlitic nodule studies give a coherent model of the crust-upper mantle structure in southeastern Australia. The presence of basaltic lower crust in granulite facies produces mineralogical phase changes that can account for the gradual change in P-wave velocity across the crust-mantle interface without the development of a Moho.

Simple

Identification info

Date (Publication)
1979-01-01T00:00:00
Citation identifier
Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/81003

Cited responsible party
Role Organisation / Individual Name Details
Publisher

Bureau of Mineral Resources, Geology and Geophysics

Canberra
Author

Ferguson, J.

1
Author

Arculus, R.J.

2
Author

Joyce, J.

3
Name

BMR Journal of Australian Geology and Geophysics

Issue identification

4:3:227-241

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
  • ACT

  • NSW

  • QLD

  • SA

  • TAS

  • VIC

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-6fc8-71e4-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/81003

Metadata linkage

https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/fae9173a-6fc8-71e4-e044-00144fdd4fa6

Date info (Revision)
2018-04-20T06:08:35
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
Read here the full details and access to the data.

Associated resources

Not available


  •  
  •  
  •