CRC LEME
Open File Report 98
ABSTRACT
Progress statement for the Kalgoorlie study area - Argo deposit,
Western Australia
Lintern, M.J. and Gray, D.J.
Investigations from previous AMIRA Projects have indicated that
Au deposits may have geochemical expression throughout the regolith.
In Project 409, knowledge gained from these earlier projects, dominantly
in areas of erosional and relict landforms, is being extended to
determine whether previously developed methods can be applied or
adapted to depositional regimes. In the Kalgoorlie area, the work
programme has been to investigate potential sample media in the
transported regolith above mineralization at a number of dominantly
palaeochannel environments. Specifically, the study has investigated
the presence of:
- Gold in surficial horizons;
- Sub-surface gold in transported overburden;
- Pathfinder elements in transported and relict regolith and bedrock.
This progress statement summarizes the recent investigations undertaken
at the Argo gold deposit (Western Mining Company Ltd) located 25
km south of Kambalda. The Argo site was chosen for further study
for many reasons including the high grade Au mineralization, the
variation in the depth of cover from about 10 m to several tens
of metres, the remoteness of the deposit from potential contributing
upstream sources and the future exposure of the mining pit, allowing
sampling from, and examination of, the pit wall.
The results indicate:
- Soil gold values are generally low (mean <10 ppb) with anomalous
gold contents (>15 ppb) located 200m from mineralization.
- Total, water- and iodide-soluble gold values are not anomalous
over mineralization.
- Gold is associated with the distribution of soil moisture in
the top metre of the profile.
- Gold is associated with calcium in the top metre of the soil
profile.
- Gold in vegetation does not locate mineralization.
- Gold is present in groundwaters over mineralization.
- Tungsten, in a variety of sample media (samples from the transported
overburden, saprolite, bedrock) appears to be a pathfinder for
gold mineralization.
- Lignitic material appears to scavenge gold and is a useful sample
medium in the transported overburden.
More information needs to be gathered from the Argo area. Specifically,
there is a need:
- To extend the auger line(s) to the west and east to establish
true background concentrations. Soil pits may be required to examine
the gold distribution in detail. Furthermore, by extending to
the east, the high proportion of water extractable gold (relative
to total gold) can be investigated.
- To construct a regolith map to put the study site in the context
of the surrounding landforms. The results suggest that there may
be anomalous gold concentrations in a clay pan adjacent to the
Argo deposit.
- To determine the significance of the anomalous total gold results
from the auger traverse on 525800N by examining and sampling a
soil profile(s).
- To analyse lignite from the transported overburden for gold
to determine its significance as a sample medium for gold exploration
in this district.
- To examine the potential of tungsten as a pathfinder for gold
mineralization.
Last updated: Sunday, August 05, 2001 11:51:00
|
