Abstract

Geoscience Australia and State and Territory Geological Surveys have systematically surveyed most of the Australian continent over the past 40 years using airborne gamma-ray spectrometry to map potassium, uranium and thorium elemental concentrations at the Earth's surface. However, the individual surveys that comprise the national gamma-ray spectrometric radioelement database are not all registered to the same datum. This limits the usefulness of the database as it is not possible to easily combine surveys into regional compilations or make accurate comparisons between radiometric signatures in different survey areas. To solve these problems, Geoscience Australia has undertaken an Australia-Wide Airborne Geophysical Survey (AWAGS), funded under Geoscience Australia's Onshore Energy Security Program, to serve as a radioelement baseline for all current and future airborne gamma-ray spectrometric surveys in Australia. The AWAGS survey has been back-calibrated to the International Atomic Energy Agency's (IAEA) radioelement datum. We have used the AWAGS data to level the national radioelement database by estimating survey correction factors that, once applied, minimize both the differences in radioelement estimates between surveys (where these surveys overlap) and the differences between the surveys and the AWAGS traverses. The database is thus effectively levelled to the IAEA datum. The levelled database has been used to produce the first 'Radiometric Map of Australia' - levelled and merged composite potassium (% K), uranium (ppm eU) and thorium (ppm eTh) grids over Australia at 100m resolution. Interpreters can use the map to reliably compare the radiometric signatures observed over different parts of Australia. This enables the assessment of key mineralogical and geochemical properties of bedrock and regolith materials from different geological provinces and regions with contrasting landscape histories. The Radiometric Map of Australia is available as a free PDF or JPG (2nd edition). The gridded digital data which underpins the Radiometric Map of Australia is available free of charge for download using the Geophysical Archive Data Delivery System (GADDS). Because the grids are large (approximately 5.5 GB each), users planning to access entire grids at full resolution should contact <a href="mailto:minerals@ga.gov.au">minerals@ga.gov.au</a> to arrange alternative means of acquiring the digital data.
Google map showing geographic bounding box with values North bound -10 East bound 156 West bound 108 South bound -42
Related Links
Web Services
Please note that you will require specialised software to use the web service(s) provided in the following link(s):

Product Type/Sub Type

nonGeographicDataset

Constraints

Creative Commons Attribution 4.0 International Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

2010-01-01T00:00:00

Product Type

nonGeographicDataset

Topic Category

geoscientificInformation

GA Catalogue Number

70791 Product http://www.ga.gov.au/metadata-gateway/metadata/record/70791/

Keywords

Geophysical Map
gamma pixel
gamma spectroscopy
geophysics
AU
Geophysics

Resource Language

Resource Character Set

Resource Security Classification

Geographic Extent

North bound
-10
East bound
156
West bound
108
South bound
-42

Lineage

Unknown

Digital Transfer Options

onLine hardcopy

Distributor

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

Source Description

Source data not available.

Metadata File Identifier

a05f7892-f8c2-7506-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 SECURITY CLASSIFICATION

Metadata Contact

Role
pointOfContact
Organisation Name
Commonwealth of Australia (Geoscience Australia)
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
Related Links
Web Services
Please note that you will require specialised software to use the web service(s) provided in the following link(s):