The Kurnalpi Gold Project is located south east of the old Kurnalpi mine workings about 95 km north east of Kalgoorlie, in the Coolgardie Mineral Field in Western Australia.
The project comprises three separate prospects located to the south east and south of the old Kurnalpi mine workings. These prospects are:
The Kurnalpi area has a history of gold mining, which available records indicate has produced in excess of 580 kg gold (18,650 ounces) from 14,292 tonnes at an average grade of 40.4 g/t gold. During the reporting period for the annual report, exploration work was carried out on Halfway Hill and Colour Dam prospects.
Regional Geology
Regional geology is characterised by elongate north to north north-westerly striking greenstone belts hosted within larger bodies of older gneiss and Late Archaean granitoids.
Recent mapping by the Geological Survey of Western Australia (GSWA) suggest division of the region into domains based on distinct stratigraphic, lithologic and structural features, bounded by regional faults and substantial shear zones such as the prominent Avoca shear.
This feature is readily apparent in the aeromagnetic data. A broad synclinal hinge zone has been identified to the immediate east of the Colour Dam Prospect. The Colour Dam syncline is a complex fold structure comprising a sequence of mafic volcanics overlain by felsic volcanics and fine grained meta-argillites and banded iron formations. The felsic volcanics comprise part of a major eruptive centre, which in the vicinity of Colour Dam was the subject of exploration for volcanogenic massive sulphide (VMS) deposits in the late 1970s.
Kurnalpi North (Halfway Hill Prospect)
The Halfway Hill Prospect is located 3km northwest of the old Kurnalpi townsite and contains exploration licence E28/465. Geological mapping, aeromagnetic and air photograph interpretations of E28/465 area and environs suggest the presence of favourable host rocks and structures carrying gold mineralisation in the Exploration Licence.
The geology of the Halfway Hill Prospect is dominated by a north-north westerly trending suite of mafic and ultramafic rocks bounded by mafic-intermediate volcanic and dolerite-gabbro intrusives.
The western contact of the mafic-ultramafic sequence is bounded by the Avoca Shear; a major structure considered responsible for localising gold mineralisation in the area. Much of the tenement area is covered with colluvium and laterite deposits, effectively masking potential gold mineralisation. Drilling by previous explorers has outlined an Inferred Resource of 300,000t at a grade of 3.0g/t gold. The geological and geophysical information suggests that this initial resource could be expanded by further exploration work.
Halfway Hill Exploration 2006/2007
To further expand the Halfway Hill Prospect's gold resources, Fairstar drilled 2,573m RC percussion along 27 holes in December 2006 and early January 2007. The holes were drilled on east-west fences, spaced 40m apart north-south and with holes spaced at 20m intervals along the fences. Holes were orientated on azimuth 90° and angled at 60° to the horizontal.
The first 40m of each hole was sampled on 4m composites. Below 40m downhole, the hole was sampled on a metre by metre basis.
The significant gold intercepts from Fairstar drilling are given in the table below:
| Drillhole | Location (m) | Gold Grade g/t | ||||
|---|---|---|---|---|---|---|
| Northing | Easting | From | To | Intersection | ||
| BBRC004 | 6622800 | 423480 | 55 | 67 | 12 | 3.14 |
| BBRC007 | 6622840 | 423460 | 54 | 78 | 24 | 1.13 |
| BBRC008 | 6622840 | 423440 | 51 | 68 | 17 | 3.29 |
| Includes | 57 | 64 | 7 | 6.94 | ||
| BBRC011 | 6622880 | 423440 | 51 | 84 | 33 | 2.37 |
| Includes | 51 | 62 | 11 | 3.34 | ||
| 77 | 84 | 7 | 3.57 | |||
| BBRC012 | 6622880 | 423420 | 56 | 59 | 3 | 4.80 |
| 69 | 76 | 7 | 2.52 | |||
| 85 | 89 | 4 | 2.08 | |||
| BBRC013 | 6622880 | 423400 | 58 | 66 | 8 | 1.52 |
| 83 | 89 | 6 | 1.25 | |||
| BBRC016 | 6622919 | 423420 | 84 | 87 | 3 | 1.83 |
| 97 | 100 | 3 | 1.30 | |||
| BBRC017 | 6622919 | 423401 | 80 | 104 | 24 | 2.87 |
| Includes | 80 | 89 | 9 | 5.1 | ||
| BBRC027 | 6623001 | 423343 | 56 | 60 | 4 | 1.13 |
A large percentage of the earlier exploration holes consist of either 2m or 4m composites. These holes are largely RAB holes. Interpretation of the existing drilling shows a possible ore shoot plunging at around 12°–15° to 340°–350° magnetic.
Several holes from the recent drilling terminated in mineralisation. Virtually no fresh rock intercepts exist in the current database. As a consequence no interpretation can be made as to the nature of the primary mineralisation.
Outlook
With the encouraging results of 2006/2007 drilling, a further drilling program of 3,000m of RC percussion and 200m of diamond (tail to RC percussion) for testing deeper extension of mineralising systems is planned. Additionally, re-logging of drill cuttings and sampling of some 4m composites at a metre by metre basis is planned.
An updated inferred resource is currently being modelled by Micromine.
Kurnalpi East (Colour Dam–Anti Dam Prospects)
The Colour Dam-Anti Dam Prospects are located 8 km south east of the old Kurnalpi townsite and cover lands of five tenements (E28/699, P28/789, P28/958, P28/993, and P28/994).
At Colour Dam gold and base metal mineralisation occurs in two distinct styles:
- Shear controlled, sheeted vein array quartz-sulphide-gold mineralisation associated with strong quartz-sericite - pyrite alteration.
- Complex brittle fracture controlled crack seal vein arrays of quartz-sulphide-gold associated with widespread quartz-sericite-pyrite alteration of the propylitically altered host dolerite.
During 1970s Colour Dam and its environs was explored for its base metal potential by companies such as, Amax Exploration (Australia) Inc, Aquitaine Australia Minerals Pty Ltd, and ESSO Exploration and Production Australia Inc. Aquitaine drilled eight diamond drill holes (at wide distances apart) and made eight intersections (in 3 holes) of 1m each with zinc values ranging from 1.1% to 1.9%.
The geology at the Prospect largely comprises a basic to felsic sequence of volcanic and volcano-sedimentary rocks ranging from ultramafic komatiites through tholeiitic basalts and dolerites through andesites to dacitic and rhyodacitic volcanic and volcaniclastic end members overlain by late tuffaceous argillites and banded iron formations.
At Colour Dam, the basic volcanic and volcaniclastic rocks are intensely altered to quartz-sericite-carbonate and pyrite is in association with quartz-sulphide vein arrays developed within shear zones associated with gold mineralisation.
At Colour Dam previous explorers have delineated an Inferred Resource of 121,000t grading 3.3g/t gold which, reportedly, remains open along strike and down dip. Overall, geological, and geophysical information suggests further potential for gold and base metals in the tenement area; exploration is warranted.
Colour Dam Exploration 2006/2007
During January 2007, the area was drill tested by 10 angled RC percussion holes, comprising a total of 863m. Of the 10 holes, three were drilled from the eastern Trial Pit wall angled at 60° towards the west. The objective of these holes was to test the extension of reported gold resource by earlier explorers beneath the eastern pit wall.
This was successfully achieved, albeit with lower gold grades than expected. However, drilling in the Trial Pit area (CDRC001) did intersect some anomalous, but sub-economical (in the present market), zinc values. The area has virtually no regolith cover, and thus holes were sampled on a metre by metre basis from the start.
The remaining 7 holes were drilled (NE of the Trial Pit) to test a geochemical gold-in-soil anomaly. The holes were arranged in three 40m by 40m fences spaced 80m apart with holes angled at 60° towards the east. Assay results of this drilling were disappointing; suggesting the absence of a gold system in the anomaly area.
The significant gold and anomalous zinc value intersections from the RC drilling at Colour Dam are given in the tables below:
| Drillhole | Location (m) | Gold Grade g/t | ||||
|---|---|---|---|---|---|---|
| Northing | Easting | From | To | Intersection | ||
| CDRC001 | 6619781 | 432879 | 18 | 36 | 18 | 1.13 |
| 50 | 53 | 3 | 1.06 | |||
| 55 | 59 | 4 | 2.66 | |||
| CDRC003 | 6619845 | 432881 | 23 | 29 | 6 | 3.97 |
| Includes | 27 | 29 | 2 | 10.6 | ||
| 50 | 56 | 6 | 1.06 | |||
| Drillhole | Location (m) | Grade ppm | Grade (%) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Northing | Easting | From | To | Intersection | Ag | Cu | Pb | Zn | |
| CDRC001 | 6619781 | 432879 | 45 | 47 | 2 | 6.3 | 171 | 817 | 1.35 |
| 56 | 66 | 10 | 5.5 | 247 | 988 | 1.21 | |||
| Includes | 56 | 60 | 4 | 5.7 | 228 | 895 | 1.45 | ||
A review of all the historical and present data indicates that the mineralisation at Colour Dam is associated with an intensely altered shear zone. Moreover, examination of gold mineralisation along cross and long sections suggests some attractive targets; such as down dip and along strike extensions to the main mineralised zone.
As in Halfway Hill, the ore envelope appears to have a northerly plunge which needs drill testing.
Further, the limited base metal assays undertaken by Fairstar confirms the presence of anomalous zinc levels reported by the 1970s base metal explorers. However, the results reported from Fairstar's drilling program, of intersections ranging from 2m to 10m and zinc values between 1.02 % and 2.03% from one location (drillhole), is a first for the area and needs detailed evaluation of its significance as a part of further exploration for base metals in the area.
Outlook
With the positive results of 2006/2007 drilling, further drilling of 2,000m of RC percussion and 100m of diamond (tail to RC percussion) to test for deeper extension of mineralising systems (down plunge targets illustrated in Figure 7) is planned.
Plans are also in place for down-hole survey of selected deeper RC holes to establish their drift. Re-logging of drill cuttings, sampling of some additional drill intersections for base metals, and analysis of all available data to understand the mineralising system(s) of the prospect and environs is also planned.
Currently an updated inferred resource is being modeled with Micromine. First pass results indicate that the 'section area' approach may have overstated the grade reported by earlier work. This will be rigorously modeled over the coming months.
Kurnalpi South
Previous exploration at this project has disclosed that on these tenements a cluster of gold soil and rock chip geochemical anomalies were followed up by several small RC percussion drilling programs which have inadequately tested these anomalies. Aeromagnetic data suggests the presence of greenstone hosted shear zones which may control the development of gold mineralisation. Some of the best RC intercepts from these programs are given below:
| Drill Hole | Down Hole Intersection Width | Assay Grade Gold (g/t) |
|---|---|---|
| KRC 13 | 3m | 7.00 |
| KRC 13 | 3m | 14.20 |
| KRC 32 | 11m | 10.90 |
| KRC 32 | 5m | 5.80 |
| KRC 55 | 2m | 19.60 |
The above intercepts suggest further follow up drill investigation of these is warranted with scope to outline a JORC compliant gold reserve within the untested shear zones and their associated quartz vein arrays.
