Gawler Calcrete Re-Analysis Project
New release
Phase 2 and 3 calcrete reanalysis project sample locations (.jpg, larger image opens in new window) View a preset map in SARIG showing Calcrete reanalysis (Note: Optiomal performance for SARIG is provided by Google Chrome, Firefox or Safari browsers) |
The aim was to detect gold deposits concealed under cover or in deeply weathered environments. Research undertaken in the late 1980s and early 1990s demonstrated that calcrete is an important, readily identifiable sampling medium (Lintern 1997).
Previously, PIRSA released a CD containing a compilation of the analytical results from some 165 046 calcrete samples contributed either directly or indirectly, by 24 companies and supplemented with additional analyses done by PIRSA. This was well received but the database had a number of unavoidable limitations arising from the diversity of approaches to sampling and analysis.
The samples
The current project is to generate and make available an analytically consistent calcrete data set and by analysing existing samples, rather than colelcting samples afresh, thereby maximising the number of results.
Gold continues to be the chief element of interest in the Gawler Craton but interest in other elements has significantly increased to include such elements as nickel and uranium. In the first phase of this project (2006) the elements gold, arsenic, nickel, copper, uranium, vanadium, silver, tungsten, cobalt, molybdenum, lead, zinc, antimony, bismuth, calcium, platinum, tellurium, gallium, selenium, manganese, cadmium, chromium, iron, magnesium, phosphorus, thallium and thorium were determined for 2692 samples. In the second phase, a further 10 500 calcretes were analysed and the elements rubidium, potassium, cerium, lanthanum and aluminium added to the analytical suite. In this release the results of a further 2400 samples have been added and all phases (15 592 samples) combined in the dataset currently offered for download.
An opportunity for the exploration industry
There remains in the order of half a million laboratory pulp samples potentially available for further analytical work, stored in the PIRSA core library (although not all will prove to be calcretes).
The Geological Survey is now in a position to take requests from the exploration industry to reassay the laboratory pulp samples.
Sample numbers can be submitted to the Manager, Geological Survey of South Australia:
Tim Baker
Email: Tim.Baker@sa.gov.au
Phone: 08 8463 3064
Technical information on the assay methods can be requested from:
Roger Fidler
Email: Roger.Fidler@sa.gov.au
Phone: 08 8463 3124
References
Lintern MJ 1997. Calcrete sampling for gold exploration. MESA Journal 5:5–8. Department of Primary Industries and Resources South Australia, Adelaide.
- Page URL: http://outernode.pir.sa.gov.au/minerals/geological_survey_of_sa/geology/geological_provinces/gawler_craton/gawler_calcrete
- Page Last Modified: May 1, 2012