The stability of magnetisation in basic igneous rocks

Special demagnetising apparatus was constructed to study the stability of several samples of basic igneous rocks from three localities in eastern Australia, particular emphasis being placed on the reliability of the directions of NRM. The direction of primary magnetisation acquired when the rocks first cooled was determined for samples at all three sites. Mesozoic dolerite from Red Hill Dyke in southern Tasmania has little or no secondary magnetisation and the mean direction of NRM is representative of the Jurassic in Tasmania. There is no evidence of systematic error due to stress or shape, and therefore the direction of NRM is a reliable estimate of the direction of the geomagnetic field at the time of intrusion. Devonian Nethercote basalt from southern New South Wales can be divided into two distinct groups, one in which the NRM is completely unaffected in either direction or intensity by demagnetisation in peak alternating fields of up to 1000 oersteds, and the other in which secondary magnetisation completely masks any primary magnetisation that may be present. Tertiary basalts from southern New South Wales show a wide range of stability. The NRM consists of primary TRM and varying proportionate amounts of secondary magnetisation, which is almost certainly viscous and which was probably acquired in the present Earth's field. The stability shown by the three rock types makes it more probable that previous palaeomagnetic results, which span a long period from Devonian to Tertiary, form a reliable record of the geomagnetic field in Australia.The general effects of alternating demagnetising fields are also discussed and a comparison made between the theoretical predictions and the data obtained.

Simple

Identification info

Date (Publication)
1971-01-01T00:00:00
Citation identifier
Geoscience Australia Persistent Identifier/https://pid.geoscience.gov.au/dataset/ga/119

Cited responsible party
Role Organisation / Individual Name Details
Publisher

Bureau of Mineral Resources, Geology and Geophysics

 Canberra
Author

Stott, P.M.

 1
Name

Bulletin

Issue identification

129

ISBN

0642948143

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

  • Bulletin

Theme

  • geology

Theme

  • magnetics

Keywords

  • AU-NSW

  • AU-TAS

  • AU-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
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Distributor

Commonwealth of Australia (Geoscience Australia)

 Voice
OnLine resource

Download the Bulletin (pdf)

Download the Bulletin (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/a05f7892-7fbf-7506-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

Legacy AGSO BMR Bulletins

Alternative metadata reference

Title

Geoscience Australia - short identifier for metadata record with

uuid

Citation identifier
eCatId/119

Metadata linkage

https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/a05f7892-7fbf-7506-e044-00144fdd4fa6

Date info (Revision)
2018-04-22T08:36:05
Date info (Creation)
1996-10-29T00:00:00

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


Keywords

geology magnetics

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