National Geochemical Survey of Australia
Commenced: July 2007
Completed: June 2011
The Geological Survey of Queensland (GSQ) collaborated with Geoscience Australia and geoscience agencies throughout Australia to conduct a survey of Australia's background geochemical concentration levels and patterns.
The survey involved sampling material derived from natural weathering and transport processes to produce well-mixed, fine-grained samples representing the average composition of large catchments as much as possible.
Sampling targeted outlet sediments, which in most cases are represented by floodplain or overbank sediments. A total of 311 of Queensland's major catchments were sampled, with an average sampling density of 1 site per 5,500km2 in the below image.
Figure 1: Boundaries of major catchments and sample sites for the Queensland component of the National Geochemical Survey of Australia
At each site, outlet sediment was taken from the top 10cm (TOS or top outlet sample) and at a depth of 60cm to 80cm (BOS or bottom outlet sample). Field information such as GPS coordinates, soil colour, pH and land use were measured and recorded. In the laboratory, the samples were dried, split and sieved before being analysed for more than 60 elements and parameters.
You can access the project data, geochemical atlas and reports for Queensland in Queensland Geological Record 2011/08 from QDEX Reports.
You can access the national survey data from Geoscience Australia.