Geochemical Atlas of Australia

The Geochemical Atlas of Australia provides data on 68 mineral elements in sediment samples which were gathered from 1315 sites in 1186 catchments across Australia as part of Geoscience Australia's National Geochemical Survey of Australia project.

At each site two depth intervals were sampled and two grain size fractions were separated from the samples. The shallower sample was from up to 10 centimetres below the surface (Top Outlet Sediment, TOS) and the deeper sample was from 60 to 80 centimetres below the surface on average (Bottom Outlet Sediment, BOS). For each depth, the coarse (<2mm) and fine (<75µm) fractions were used for chemical assays. The samples were prepared and analysed for up to 68 chemical elements using a range of techniques which yielded Total, Aqua Regia soluble and Mobile Metal Ion™ soluble concentrations. Additionally, a bulk split was used for the determination of bulk soil properties. For more detail, please see Caritat et al. (2009, 2010) and Caritat and Cooper (2011a) in the Further reading section below.

Symbology

Map symbology is based on exploratory data analysis principles. A small circle symbol (○) is assigned for data between the minimum and the 25th percentile, a small dot (.) for data between the 25th percentile and the median, a larger dot (*) for data between the median and the 75th percentile and a plus sign (+) for data between the 75th percentile and the maximum. Lower outliers, if present, are assigned a large circle symbol (◯). Upper outliers, if present, are assigned a large solid square symbol (■). For more detail, please see Caritat and Cooper (2011b) in the Further reading section below.

Image preview

All the geochemical and bulk properties maps produced by the NGSA project are listed in the table below. A low-resolution preview of each map can be viewed via the links and the next or previous map of the series can be viewed by clicking the NEXT or PREVIOUS button in the top of the image. The maps can be downloaded in element-related packages (e.g. all the calcium (Ca) maps in one package), or all maps can be downloaded as the National Geochemical Survey of Australia - The Geochemical Atlas of Australia.

Loss on Ignition

• Download all Loss on Ignition maps
• Loss on Ignition TOS coarse map [JPEG 109KB]
• Loss on Ignition TOS fine map [JPEG 109KB]
• Loss on Ignition BOS coarse map [JPEG 109KB]
• Loss on Ignition BOS fine map [JPEG 109KB]

Bulk properties

• Field pH
  • Download all Field pH maps
  • Field pH TOS map [JPEG 109KB]
  • Field pH BOS map [JPEG 109KB]
• pH 1:5
  • Download all pH 1:5 maps
  • pH 1:5 TOS map [JPEG 109KB]
  • pH 1:5 BOS map [JPEG 109KB]
• EC 1:5
  • Download all EC 1:5 maps
  • EC 1:5 TOS map [JPEG 109KB]
  • EC 1:5 BOS map [JPEG 109KB]
• Grain size
  • Download all Grain size maps
  • Sand (2000-20µm) TOS map [JPEG 109KB]
  • Sand (2000-20µm) BOS map [JPEG 109KB]
  • Silt (20-2µm) TOS map [JPEG 109KB]
  • Silt (20-2µm) BOS map [JPEG 109KB]
  • Clay (0-2µm) TOS map [JPEG 109KB]
  • Clay (0-2µm) BOS map [JPEG 109KB]

Further reading

Caritat P de, Cooper M, Lech M, McPherson A and Thun C 2009. National Geochemical Survey of Australia: Sample Preparation Manual. Geoscience Australia Record, 2009/08, 28 pp.

Caritat P de, Cooper M, Pappas W, Thun C and Webber E 2010. National Geochemical Survey of Australia: Analytical Methods Manual. Geoscience Australia Record 2010/15, 22 pp.

Caritat P de and Cooper M 2011a. National Geochemical Survey of Australia: Data Quality Assessment. Geoscience Australia Record 2011/21, 478 pp.

Caritat P de and Cooper M 2011b. National Geochemical Survey of Australia: The Geochemical Atlas of Australia. Geoscience Australia Record 2011/20, 557 pp.

Caritat P de, Cooper M, Jaireth S and Bastrakov E 2011. National Geochemical Survey of Australia: Preliminary Implications for Energy and Mineral Exploration. Geoscience Australia Record, 2011/29, 84 pp.

Wilford JR, Caritat P de, Cooper M and& Minty BRS 2011. National Geochemical Survey of Australia: Comparison of Geochemical and Airborne Radiometric Data. Geoscience Australia Record, 2011/39, 35 pp.