Authors / CoAuthors
de Caritat, P.
Abstract
The National Geochemical Survey of Australia (NGSA) project (www.ga.gov.au/ngsa), part of Geoscience Australia's Onshore Energy Security Program 2006-2011, was carried out in collaboration with all state and territory geological surveys. It delivered Australia's first national geochemical atlas, the underpinning geochemical database, and a series of reports and papers. Catchment outlet sediments (mostly similar to floodplain sediments) were sampled in 1186 catchments covering ~6.2 million km2 or ~81% of the country (on average one sample per 5200 km2). Samples were collected at two depths (0-10 cm and ~60-80 cm), each sieved to two grain size fractions (<2 mm and <75 mm) and analysed for total, aqua regia, and Mobile Metal Ion® element contents; other analyses (pH, electrical conductivity, grain size distribution, spectroscopy, etc.) were also performed. Results to date have been used to: (1) investigate first-order controls on the geochemical makeup of Australian regolith in comparison to Europe; (2) compile preliminary, multi-continental, empirical 'Global Soil' reference values; (3) produce continental-scale soil pH maps; (4) map Fe oxide mineralogy and soil colour; (5) investigate the level and distribution of bioavailable elements in Australia; (6) determine element associations by multivariate statistical methods and compare resulting patterns to independent geoscience datasets; (7) model the distribution of soil carbonate using multiple environmental covariates; (8) assess the potential of the dataset for mineral prospectivity analysis (e.g., for base metals, U, Au and REEs); (9) select salt lakes to be investigated for their potential to host potash, Li and B resources; (10) ground truth, infill and 'correct' airborne radiometric concentration data for K, U and Th; and (11) shed light on the phenomenon of disequilibrium in the radioactive decay chain of U by comparing actual to estimated U concentrations at the continental scale. The NGSA project was Australia's first national-scale geochemical survey, requiring certain strategic decisions to be taken about sampling medium, density, etc. The resulting atlas and dataset have proven useful and applicable to many end-uses, but limitations and challenges exist as in every geochemical survey.
Product Type
nonGeographicDataset
eCat Id
75771
Contact for the resource
Custodian
Owner
Custodian
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
-
- External Publication
- Australian and New Zealand Standard Research Classification (ANZSRC)
-
- Environmental Science and Management
-
- Published_Internal
Publication Date
2013-01-01T00:00:00
Creation Date
Security Constraints
Legal Constraints
Status
Purpose
Maintenance Information
notPlanned
Topic Category
geoscientificInformation
Series Information
Lineage
National Geochemical Survey of Australia (NGSA) Keynote Address Goldschmidt Conference 2013
Parent Information
Extents
[-44, -10, 112, 154]
Reference System
Spatial Resolution
Service Information
Associations
Downloads and Links
Source Information
National Geochemical Survey of Australia (NGSA) 112.0 154.0 -44.0 -10.0