Citation

Geoscience Australia provides most of its products for free under a Creative Commons Attribution 4.0 International Licence. We only require that you reference the use of our data or information using the following citation:
Gidley, P.R., 1981. Discrimination of surficial and bedrock magnetic sources in the Cobar area, NSW. BMR Journal of Australian Geology and Geophysics  6:1:71-79. Bureau of Mineral Resources, Geology and Geophysics, Canberra.

Abstract

Known mineral deposits in the Cobar area of NSW are magnetic. Hence, the magnetic method is an important tool in the search for mineral deposits in this area. Unfortunately, widespread occurrences of near-surface magnetic mineral accumulations commonly produce aeromagnetic anomalies similar to those expected from bedrock sources. Work by BMR during 1978 and 1979 has shown that the near-surface response is caused by laterite, which contains concentrations of hematite/maghemite minerals with high magnetic remanence and/or susceptibility. These magnetic minerals usually occur in surface layers up to 10 m thick and exhibit large lateral and vertical variations in magnetic properties over small distances. Frequency domain analysis of both model and field magnetic data shows the spectral signatures of bedrock and near-surface sources to be distinctly different. Hence, spectral techniques may be used to separate the responses of bedrock and near-surface sources which occur at the same locality, if high resolution data are available. A comparison of the response of near-surface and bedrock sources by modelling indicates that, with careful survey design, a magnetic target such as Elura could be detected at a depth of 300 m, even in areas of severe surface magnetic noise.
Google map showing geographic bounding box with values North bound -31.0 East bound 147.0 West bound 145.5 South bound -32.0
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Product Type/Sub Type

nonGeographicDataset - GA Publication - Journal

Constraints

license
Creative Commons Attribution 4.0 International Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

1981

Product Type

nonGeographicDataset

Topic Category

geoscientificInformation

Keywords

GA Publication
Journal
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound
-31.0
East bound
147.0
West bound
145.5
South bound
-32.0

Lineage

Unknown

Digital Transfer Options

onLine

DISTRIBUTION Format

pdf

Distributor

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

Metadata File Identifier

fae9173a-7002-71e4-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

2015-05-19

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

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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).