The Barton West Project is located within the Eucla Basin District of South Australia, where a number of Heavy Mineral Sands deposits have been discovered, including the world class Ambrosia and Jacinth deposits currently being developed by Iluka Resources.
Drilling programs completed prior to the current year had outlined a very large area (30 km N-S and up to 15 km E-W) of anomalous heavy mineral sands (HMS) development.
During the year closer spaced drilling was carried out within a 3 km x 3 km area to better facilitate an understanding of the controls and continuity of potentially economic HMS.
TZ Minerals International Pty Ltd (TZMI), internationally acknowledged consultants to the HMS industry, were engaged during the year to carry out a review of the project. Following advice from TZMI, resource estimation was carried out applying the following parameters:
- Interpretation of the continuity of HMS requires accurate definition of level data. Accordingly, Shuttle Radar Topography Mission (SRTM) data were acquired to produce a more accurate digital elevation model.
- Resources should reflect continuity of consistent trends at consistent levels. These trends are mainly interpreted to be palaeo ‘strand lines’. However, there also appears to be an area of significant continuity which is interpreted to represent a ‘lagoonal facies’ development.
- A 2% HMS lower cut off grade was used.
- Overburden ratios have been estimated.
- Mineralogical data is based on ‘modal analyses’ undertaken by Diamantina Laboratories and XRF determinations undertaken by Ultra Trace Laboratories.
The resulting resource estimate is tabulated below:
| Inferred Resources |
Tonnes (million) |
HM (%) |
Overburden Ratio |
| Strand Line Facies |
81.6 |
3.1 |
3.6 |
| Lagoonal Facies |
90.1 |
2.5 |
3.8 |
| TOTAL |
171.7 |
2.8 |
3.7 |
This estimate compromises multiple separate zones as illustrated in the following figure:
Some of the individual strand line zones are detailed in the following table:
| Section |
Tonnes |
HM (%) |
Strip Ratio |
| SL-3 |
19,997,094 |
3.42 |
2.6 |
| SL-5 |
4,686,077 |
2.37 |
1.9 |
| SL-9 |
2,600,292 |
3.12 |
1.8 |
| SL-15 |
8,796,690 |
4.39 |
2.2 |
| SL-26 |
2,474,371 |
2.37 |
2.2 |
| TOTAL |
39,572,002 |
3.42 |
2.3 |
More targeted drilling in the area of these, and the other zones, has the potential to extend and/or link them.
Mineralogical data is based principally based on ‘modal analyses’ undertaken by Diamantina Laboratories.
Mineral assemblage results are quite diverse, as shown in the examples in the following table:
| Zircon (%) |
Rutile (%) |
Leucoxene (%) |
Ilmenite (%) |
Sub-Total |
| 4.0 |
3.0 |
9.8 |
64.9 |
81.7 |
| 8.6 |
4.7 |
21.2 |
48.7 |
83.2 |
| 10.6 |
2.4 |
15.2 |
61.7 |
89.9 |
| 2.4 |
2.7 |
13.8 |
35.3 |
54.2 |
| 15.6 |
6.6 |
7.1 |
62.7 |
92.0 |
| 5.6 |
1.0 |
8.6 |
72.8 |
88.0 |
| 0.4 |
2.7 |
5.8 |
28.2 |
37.1 |
| 20.9 |
5.1 |
13.3 |
54.1 |
93.4 |
| 34.8 |
3.8 |
7.7 |
47.8 |
94.1 |
| 3.2 |
13.7 |
20.1 |
57.0 |
94.0 |
Within the areas of the resource estimates average mineral assemblages were calculated as: Zircon – 10%, Rutile & Leucoxene – 20%, Ilmenite – 60% (indicated to be pseodorutile both by Diamantina’s modal analyses and work carried out by CSIRO.
Summary
The ‘strand line’ resource estimate consists of multiple separate zones, many of which have the potential to become linked with further infill drilling. There is also the potential to define continuity outside of the resource area.
The overall area of mineralisation is large and, apart from the more closely drilled area in the southwest corner (which comprises about 25% of the total area), there are additional indications of more typical strandline development. Drilling is very wide-spaced, so it is quite possible that there are economic accumulations between and below the existing drill holes.
With a better understanding of the geology, it will now be possible to target a more focussed exploration program. |
