Synopsis
In recent years rigorous and robust regional geochemistry has been under-acquired and under-utilised in both precompetitive and mineral exploration programs in South Australia. To address this imbalance this project includes five main components, mainly focused on application in the far west of South Australia:
- Documentation and new regional geochemistry/biogeochemistry methodology
- Coompana regional geochemistry/biogeochemistry characterisation
- Fowler Domain exploration target geochemistry/biogeochemistry pilot study
- Western Gawler Craton plant biogeochemistry rhenium (Re) anomalism follow-up survey
- Acquisition and workflow development for new portable X-ray Fluorescence (pXRF) instrument to be housed at the South Australia Drill Core Reference Library, Tonsley
Background and aims
This project will be one of the first major Geological Survey of South Australia (GSSA) geochemical programs in recent years with the development of new methodologies (eg methodology report) and new technologies (eg new generation pXRF instrument) for new regional geochemistry and biogeochemistry surveys in the far west of South Australia.
A new regional soil geochemistry and plant leaf biogeochemistry survey is proposed for the area of the Coompana magnetic anomaly. The new study will build upon an earlier biogeochemistry pilot study that offered some promise for surficial expression of deep geochemical sources on the southern margin of the Coompana magnetic anomaly. This will include a helicopter access gridded soil and plant biogeochemical sampling program in early 2017 followed by analysis and report compilation.
A pilot study of selected case studies for a range of surficial geochemical sampling media across selected exploration targets in the Fowler Domain will also be tested and assessed as the basis for further regional survey and/or mineral exploration. This will help develop an understanding for the benefits of further geochemical/biogeochemical exploration techniques that have been little used in this region.
A small follow-up program to investigate Re biogeochemical anomalies (100s ppm Re) closely corresponding to deep crustal conductivity structures (shown in the magnetotellurics data) will be resampled and mapped in the area of the western Gawler Craton. This will be compared with a further Re anomaly occurrence also associated with the Paralana Fault in the northeastern Flinders Ranges. This project component has the potential to further illuminate the links between deep crustal conductivity and their geochemical expression and characteristics and, in turn, the use of geochemistry for the extension and follow-up of regional magnetotelluric surveys such as AusLAMP.
Key outcomes
- Regional geochemistry methodology report to provide the benchmark methodology for how the regional geochemistry surveys will be conducted. This report will also be of value to industry when using this data and when planning infill programs.
- Regional geochemistry/biogeochemistry report for Coompana region
- Regional geochemistry/biogeochemistry report for Fowler Domain
- Regional biogeochemistry follow-up on regional Re anomalies with deep crustal structures
- New generation portable X-ray Fluorescence (pXRF) instrument, particularly for use on regional drill core at South Australia Drill Core Reference Library