research program 2
mineral exploration in areas of cover
Predictive geochemistry in areas of transported overburden: Mechanisms of anomaly formation
AMIRA P778
Project Leader : Dr Ravi Anand, CSIRO Exploration and Mining
Start date and duration: March 2006-March 2009 (CRC LEME participation expires 30 June 2008)
Participants : CSIRO Exploration & Mining, CSIRO Land & Water, Adelaide University, Curtin University, and AMIRA - Barrick Gold, BHP Billiton, Cameco Corporation, Inco Resources (Australia) Pty Ltd, Independent Gold NL, Newmont Australia Ltd, SGS Minerals, Tech Cominco Ltd.
Brief project description :
As the discovery rate of world-class mineral deposits continues to decline in Australia and other parts of the world, increased attention is being focused on geochemical exploration methods designed for covered terrains. If definitive, low cost surface or near-surface sampling surveys can be conducted in areas of shallow cover (say <30m), large areas can be tested and expensive unnecessary drilling can be reduced. In order to apply geochemical exploration methods confidently in a given area, or to be able to determine that such techniques are inappropriate, it is necessary that we understand the mechanisms by which surface expressions may form. Explorers will then be better able to decide whether to do further drilling given a specific response at the surface. Research is required that will determine which mechanisms can cause metal migration through post-mineralization cover.
As mineral exploration moves into regions dominated by shallow transported cover, conventional approaches are simply not applicable and thus increasingly there is a need for new innovative approaches to geochemical exploration. However to develop such new approaches there is a major need to identify the operating mechanisms capable of transferring metals from buried mineralization upwards through barren cover to the surface.
Understanding the processes of metal transport through transported overburden requires expertise and experimental techniques from a wide range of disciplines. In the proposed project the researchers will be using a combination of field and analytical techniques derived from soil science, botany, molecular microbiology, geochemistry, plant chemistry, hydrogeochemistry and regolith geology.
The main objective of the proposed project is to determine the mechanism(s) for formation of geochemical anomalies in transported overburden in a variety of Australian environments and, based on these mechanisms, to develop effective and reliable geochemical exploration techniques. The research focus will be on:
• Studies to develop practical sampling strategies and methodologies in areas of transported cover based on biota, soil and gas investigations.
• Experimental and theoretical work on the mechanisms leading to the formation of surface anomalies. This will provide the framework and constraints for the practical sampling methods.
The researchers will apply a range of techniques such as vegetation analysis of various plant species, metal uptake in the rhizosphere (plant-root zone), mass balance studies, in-house lab and greenhouse studies; groundwater geochemistry and redox analysis, microbial characterization including their role in gas generation and mineral-trace element biotransformation (solubilisation/precipitation) throughout the profile, isotope analysis to establishing source of metal in plants and soil, using artificial inserted adsorbent collectors to detect surface geochemical anomalies and utilising other research on soil desorption analysis to test gas migration possibilities. The researchers will use a combination of in situ and in vivo spectroscopic techniques such as synchrotron-based techniques, nanosims, electron microprobe and laser ablation ICP-MS to determine the nano-scale location of metals in vegetation and regolith materials.
Sponsors of the project: BHP Billiton, Cameco Corporation, Teck Cominco, Independence Gold, SGS Minerals, Barrick Gold, Inco and Newmont.
The project will cost AUD$3,040,351 over three years which includes AMIRA International's project development and administration fee but excludes the 10% Goods and Services Tax from Australian based companies. Total cash and in-kind contributions of AUD$1,984,151 (including AUD$255,000 cash from LEME) will be provided by CRC LEME through its core participants: CSIRO (as represented by Exploration & Mining and Land & Water), Curtin University , and Adelaide University . CSIRO would provide an in-kind contribution of $140,946 in the 2008/09 financial year. The balance of AUD$915,254 is obatined from industry through AMIRA. Companies who are members of AMIRA International the individual sponsorship required is AUD$38,100 per annum (exc. GST for Australian based companies) over three years and non-AMIRA members are required to pay a AUD$7,200 per annum surcharge.
Deliverables (outputs) and expected impacts of research (outcomes):
Scientific Deliverables (new scientific advances)
(i) Improved scientific understanding of the mechanisms that are responsible for metal migration through transported cover;
(ii) Guidelines for assessment of which transported regolith environments metal dispersion is possible in and what sample media/techniques are most likely to detect it.
(iii) New cost-effective and practical exploration method(s), with higher reliability and probability of success; (distinction between negative and null result)
(iv) Potential to use new exploration methods in other parts of the world.
Deliverables to Client (Adoption mechanisms)
i. Technical reports describing the work completed at each study site;
ii. Technical report summarizing experimental and theoretical work on sampling strategies, sample preparation and sample analysis;
iii. Final report on mechanistic models to account for observed metal migration or its absence, integrating all aspects of the study including different regolith and palaeo-climatic controls on migration, and variations with respect to different commodity elements.
iv. National and international publications in peer reviewed journals.
Milestones:
May 2006: Commencement of project
May 2007: Interim report on practical sampling strategies and results on mechanisms.
May 2008: Interim Report with emphasis on mechanistic and experimental studies
May 2009 Final Report
Confidentiality requirements - The outcomes will be confidential to sponsors during and up to one year after completion of the three year project, after which researchers have the right to publish.
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