Ashburton Project
1. ASHBURTON COPPER GOLD BASE METALS PROJECT
1.1 LOCATION AND ACCESS
The Ashburton Project is located approximately 60 kilometres south of the Nanutarra-Paraburdoo road on Wyloo and Kooline Stations in the Ashburton Mineral Field, of Western Australia. The centre of the project is approximately 185 kilometres from Paraburdoo and 100 kilometres from Nanutarra.
1.2 TENURE
Athena?s Ashburton Project (Figure 2) covers about 1,020 square kilometres and consists of one Mining Lease (M08/189) 90%, three Exploration Licences (EL08/1641, EL08/1679 and EL08/1680) 100% and a Prospecting License (P08/493) 95%.
1.3 PROJECT GEOLOGY AND MINERALISATION
Athena?s tenements encompass rocks of the Ashburton and Capricorn formations of the Wyloo Group along the northern margin of the west Bangemall Basin. Area selection was driven by studies of the regional geophysics which indicate a number of elements conducive to the formation of large mineral systems. The combination of granitic intrusions, folds and thrust faults is of particular interest as these provide a source of heat and the structures to focus and trap mineralising fluids.
A number of lead, copper and gold occurrences are located within Athena?s project area and anomalous gravity and magnetic responses are evident in the regional data sets. Previous work has largely been confined to surface geochemistry and prospecting along the access corridors with limited follow-up drill testing. The Western Australian Geological Survey?s regional sampling programme has identified geochemical anomalies that warrant follow-up testing.
The region is reasonably remote and rugged and Athena?s tenements have been only lightly explored. Conceptual targets include large orogenic mesothermal saddle-reef and stock-work style gold/base metal deposits comparable to Bendigo and Ballarat in Victoria, Enterprise at Pine Creek in the Northern Territory and Telfer in Western Australia. The Ashburton district was the site of some of earliest gold discoveries recorded in Western Australia but was soon overlooked as discoveries were made at Southern Cross and Coolgardie.
1.4 WORK COMPLETED BY ATHENA
Athena completed a helicopter borne VTEM survey at Kooline in December 2006 and commissioned Hyvista Corporation to fly an orientation hyperspectral survey. The Company has acquired the latest regional magnetic and radiometric data sets flown at 400 metre line spacing for the state government and integrated these, together with most recent aerial photography, in a GIS environment.
In December 2007 Digital Mapping Australia (DiMap) flew high-resolution (10cm) digital aerial photography over an area centred on the Kooline mining area. This data was used to generate high quality seamless digital images and digital terrain models (DTM) to aid outcrop and regolith mapping, and assist with the planning and interpretation of the surface geochemistry surveys.
Rock Chip Sampling
During the year Athena completed extensive rock chip sampling programs aimed at identifying and characterising mineralisation at the silver-lead mines and in adjacent outcrops at Kooline in the Ashburton. The peak results for gold (Au), silver (Ag), lead (Pb), and copper (Cu) from these sampling programs are listed in Table 1. The combined strike length of the three anomalous outcropping trends identified by Athena at Kooline is 11.4 kilometres.
The initial program resulted in the identification of two new anomalous trends with distinct copper-gold and coppergold- lead signatures which are to the north and south of, and run parallel to, the known silver-lead mineralisation. The three trends are labelled ?Gold Zone?, ?Lead Zone? and ?Copper Zone? on figure 3. These zones are also characterised by slightly different orientations and markedly different arsenic and antimony signatures, suggesting that the different styles of mineralisation are not be related.
A second field mapping and rock chip sampling program tested favourable geological positions and historical prospecting sites that were identified during the analysis of the high resolution aerial photography and DTM data.
Rock chip sampling of the remnant mineralisation in the Kooline lead workings shows the area to be characterised by veins of high-grade silver-bearing galena (lead sulphide). The mineralisation varies in width from stingers a few millimetres wide to over 30 centimetres. Records indicate that stopes were developed on lenses of ore up to 2 metres thick and 50-200 meters long. The grades obtained by Athena are consistent with production records for the mines, which produced over 3,600 tonnes of lead and 950 kilograms (30,000 ounces) of silver. Athena has located 130 prospecting pits and shafts that date from the 1950?s, 10 of which have extensive development. None have been drilled tested.
Figure 2
Table 1
| Rock Chip Analyses from Athena?s Ashburton Project Selected Samples and Elements (sorted by location) | |||||||
|---|---|---|---|---|---|---|---|
| Sample | MGA 50East | MGA 50North | Copper (%) | Gold (g/t) | Silver (g/t) | Lead (%) | Mineralised Trend |
| AKCR048 | 442026 | 7443745 | 3.78 | 0.34 | 375 | 42 | Copper Zone |
| AKCR023 | 445076 | 7442573 | 1.63 | 0.31 | 20 | *NSA | Copper Zone |
| AKCR047 | 442132 | 7443764 | 1.49 | 0.21 | 245 | 58 | Copper Zone |
| AKCR045 | 442538 | 7443559 | 0.70 | 0.51 | 280 | 56 | Copper Zone |
| AKCR046 | 442389 | 7443578 | 0.44 | 0.23 | 120 | 46 | Copper Zone |
| AKCR013 | 446320 | 7441999 | 0.29 | 0.41 | 35 | 12 | Copper Zone |
| AKCR044 | 442560 | 7443552 | 0.27 | 0.11 | 225 | 46 | Copper Zone |
| AKCR038 | 444290 | 7442871 | 0.15 | 0.10 | 85 | 42 | Copper Zone |
| AKCR035 | 446186 | 7441136 | NSA | 0.79 | NSA | NSA | Copper Zone |
| AKCR041 | 444973 | 7445336 | NSA | 0.10 | 155 | 59 | Gold Zone |
| AKCR015 | 444566 | 7443542 | NSA | 0.19 | 210 | 43 | Silver-lead Zone |
| AKCR016 | 445304 | 7443878 | NSA | 0.04 | 40 | 37 | Silver-lead Zone |
| AKCR007 | 443591 | 7443844 | 2.15 | 0.56 | 175 | 34 | Silver-lead Zone |
| AKCR060 | 446153 | 7443040 | 2.07 | 0.60 | 580 | 30 | Silver-lead Zone |
| AKCR049 | 442274 | 7445505 | 0.99 | 0.15 | 220 | 68 | Silver-lead Zone |
| AKCR004 | 443554 | 7443569 | 0.43 | 0.32 | 65 | 26 | Silver-lead Zone |
| AKCR052 | 441685 | 7445854 | 0.43 | 0.05 | 30 | 8 | Silver-lead Zone |
| AKCR005 | 443559 | 7443720 | 0.38 | 0.70 | 30 | 5 | Silver-lead Zone |
| AKCR051 | 441541 | 7445930 | 0.24 | 0.18 | 60 | 18 | Silver-lead Zone |
| AKCR056 | 442936 | 7444392 | 0.06 | 0.11 | 140 | 49 | Silver-lead Zone |
| AKCR061 | 445897 | 7443190 | 0.04 | 0.01 | 65 | 21 | Silver-lead Zone |
| AKCR057 | 445376 | 7443407 | 0.02 | 0.13 | 70 | 25 | Silver-lead Zone |
| AKCR059 | 446185 | 7443007 | 0.02 | 0.03 | 120 | 56 | Silver-lead Zone |
| AKCR058 | 446191 | 7443399 | 0.01 | 0.46 | 70 | 31 | Silver-lead Zone |
| *NSA: No Significant Assay | |||||||
The trend referred to in figure 3 as the ?Lead Zone? is centred on the old Kooline mine workings. It extends for approximately 5.6 kilometres in a north-westerly direction. The two kilometre northwest trend defined by samples AKCR049, 051, 052, and 056 has extended the known ?Lead Zone? mineralisation, with the remaining samples extended this zone to the southeast. Samples AKCR048 (0.34g/t Au, 375g/t Ag, 42.5% Pb, 3.78% Cu), AKCR049 (0.15g/t Au, 220g/t Ag, 68.4% Pb, 0.99% Cu), and AKCR060 (0.60g/t Au, 580g/t Ag, 29.9% Pb, 2.07% Cu) confirm the potential for high grade polymetallic mineralisation along this trend.
Athena?s maximum result was 68% lead with 220g/t silver in sample AKCR049. The maximum silver value was 580g/t in sample AKCR060; this sample also contained 30% lead and 2.03% copper. The mean of the assays for all 66 rock chip samples were; 0.17g/t gold, 0.27% copper, 63 g/t silver and 16% lead.
The copper and gold association in the ?Gold? and ?Copper Zones? is particularly encouraging. The zones are located sub-parallel and approximately 1700 metres and 800 metres respectively north and south of the ?Lead Zone?. The maximum copper value obtained by Athena was from this zone in sample AKCR048, which assayed 3.78% copper, 375g/t Silver and 42% lead. Samples AKCR044 to AKCR048 are approximately two kilometres along strike of the area shown as the ?Copper Zone? on figure 3. The outcropping strike length of the ?Copper Zone? is approximately 4.6 kilometres.
AKCR035 assayed 0.79g/t gold and is significant as it is from another parallel structural trend 800m to the south of the ?Copper Zone?. This result, from outside of the area of the historic workings covered by soil sampling, verifies the association between host rock, structure and mineralisation.
Sample AKCR041 (59.1% Pb, 155g/t Ag) was a rock chip from a shear zone within the ?Gold Zone? north of the lead workings. No lead mineralisation had been previously recorded from this area and there are no prospecting pits at this locality. The area surrounding this sample has a distinct ?gold?copper? signature in the soil geochemistry. The ?Gold Zone? has a strike length of 1.2 kilometres in outcrop.
The gold and copper mineralisation at Kooline is associated with quartz veins and stockworks adjacent to shears along fold axes trends east-southeast to west-northwest parallel to the Kooline lead workings. The rock chip surveys encouraged Athena to test below the shallow alluvial veneer that surrounds the lead workings with a soil auger sampling program. The alluvium would have masked mineralisation from historical prospecting methods.
Soil Sampling
In September 2007 Athena carried out an orientation soil geochemical survey at the Kooline lead-silver mines and on three other areas on the Ashburton Project tenements. A follow-up auger soil geochemical sampling program designed to explore for mineralisation under the thin veneer of colluvium and alluvium surrounding these same areas was carried out in May 2008. This follow-up program was an outstanding success. In the first program five hundred soil samples were collected from four target areas. Two of these areas, the Kooline silver-lead and recently identified parallel zone of copper mineralisation, have outcropping quartz veins with visible lead and copper mineralisation. The other two areas had no known mineralisation. The peak assay results for gold, copper and lead are listed in Table 2.
The initial soil sampling program demonstrated that in areas of outcrop soil geochemistry is a cost effective exploration tool and confirmed the three parallel east-west trends first identified in the rock-chip samples. As with the rock samples the northern zone is strongly anomalous in gold; the middle zone, over the lead mines is anomalous in lead and the southern zone is typified by elevated copper and gold.
Figure 3
Figure 4
Figure 5
Figure 6
Table 2
Top Ten assays for selected elements first soil sampling |
|||
|---|---|---|---|
| Rank | Au ppb | Cu ppm | Pb ppm |
| 1 | 331 | 235 | 3800 |
| 2 | 292 | 228 | 3140 |
| 3 | 202 | 156 | 1180 |
| 4 | 184 | 126 | 2265 |
| 5 | 168 | 126 | 1860 |
| 6 | 138 | 130 | 1340 |
| 7 | 121 | 106 | 1310 |
| 8 | 116 | 104 | 1070 |
| 9 | 106 | 102 | 1060 |
| 10 | 91 | 100 | 1060 |
| (Note: 10,000ppm = 1% and 1,000ppb = 1ppm) | |||
The follow-up May 2008 auger soil geochemical sampling program extended the area covered by the soil geochemistry to include extensive areas of shallow sheet wash and colluvium. The soil samples in this latest survey were collected to a maximum depth of 1.7 metres using a power auger mounted on a bob-cat. Hilly terrain and incised drainages not accessible by the bob-cat were excluded from the survey and as a result several anomalous trends remain open. This auger soil survey confirmed and extended the results of Athena?s orientation soil sampling program.
Athena is further encouraged by the fact 634 of the 863 auger holes reached blade refusal in less than 1.5 metres suggesting that the extensive alluvial plains away from the Ashburton River are mostly thin veneers which can be cost effectively explored using this approach.
The top ten assays for gold (Au), copper (Cu) and lead (Pb), together with a statistical summary of the results from the auger survey is provided in Table 3. The locations of the samples for gold, copper and lead anomalies are shown on the attached maps (Figures 4 to 6). Fifty-eight (58) of the 863 samples assayed 10ppb gold or better. The maximum gold assay of 496ppb was again from the ?Gold Zone?, a coincident gold-copper anomaly in the northeast of the survey area. This anomaly was enhanced and extended by the auger survey and now exceeds 1.5 kilometres in length and is open in both the easterly and westerly directions.
A number of anomalous trends are apparent in the data and the majority of these are open along strike. The copper-gold trend in the south of the survey area has also been extended and enhanced. This anomaly, as defined by the 30ppm copper contour, is over 6 kilometres in a northwest-southeast orientation and open in both directions. The peak copper assay (388ppm) came from in the southeast corner of this zone. This anomalous trend intersects with an east-northeast trending copper-gold anomaly that runs along a creek system interpreted to be a structural zone of interest.
The peak lead results are mainly concentrated adjacent to the Kooline lead mining centre, although encouraging results were recorded in the southeast corner of the survey area, coincident with the peak copper assay. This area is covered by thin alluvial sheet wash, which would have masked mineralisation to prospectors in the 1950?s. Similar results were achieved in covered areas along strike of the old lead workings, providing Athena with additional exploration drill targets.
Table 3
Top Ten assays for selected elements from Auger sampling |
|||
|---|---|---|---|
| Rank | Au ppb | Cu ppm | Pb ppm |
| 1 | 496 | 388 | 1260 |
| 2 | 189 | 238 | 1250 |
| 3 | 117 | 154 | 1180 |
| 4 | 80 | 144 | 985 |
| 5 | 62 | 138 | 727 |
| 6 | 43 | 130 | 715 |
| 7 | 36 | 128 | 412 |
| 8 | 33 | 114 | 378 |
| 9 | 30 | 112 | 376 |
| 10 | 28 | 96 | 272 |
| (Note: 10,000ppm = 1% and 1,000ppb = 1ppm) | |||
Airborne Geophysical Survey
UTS Geophysics, the Company?s airborne geophysical contractor, flew a combined high resolution aeromagnetic and radiometric survey on lines 50 metres apart and 30 metres above the ground over the Kooline area (Figure 2). Athena is confident additional exploration targets will be generated when a structural interpretation of the data from this survey, along with the integration of the auger soil geochemistry and known surface gold, copper and lead mineralisation is finalised.
Ground Geophysical Results
Athena employed a geophysical survey contractor to undertake Gradient Array Induced Polarisation (IP) surveys on an initial four grids targeting the previously defined and announced Lead, Copper, and Gold zones (Figure 1). An additional Gradient Array grid was included on the Copper zone to delineate an exciting anomaly highlighted in the initial field results, along with two Dipole-Dipole IP lines over selected results from the survey. The Gradient Array grid has provided a surface plan of the resistivity and chargeability of the underlying geology and the Dipole-Dipole lines give an indication of the depth and direction. The Dipole-Dipole survey has enhanced interpretation of the Gradient Array data and enabled the planned drill holes to be optimally positioned.
Figure 1
Figure 2
The most significant result from the IP survey is the coincidence of historical workings aligning along the edge of the Gradient Array chargeability responses. It is a possibility that the historic mining and prospecting has occurred along the margins of the main zones of mineralisation. The coincident chargeability and resistivity anomalism suggests that the response is due to quartz-hosted sulphides, similar to which is observed in the historic workings. This encouraging response also enables Athena to re-interpret and integrate the previously acquired airborne and ground electromagnetic datasets.
The chargeability response for each of the grids is shown in the attached plans, along with historic workings, anomalous resistivity trends, and target zones. The 800m x 400m Grid 1 was positioned over an area where Athena has previously reported rock chip results of 3.78% Copper; 42.5% Lead; 375g/t Silver. Figure 2 shows a 450m long anomalous zone which is significantly higher in amplitude than that of the mineralisation associated with historic workings. Importantly there are small prospecting pits on the edge of the response with the main part under shallow cover which possibly masked it from historical prospecting. Athena will now target this zone as part of the proposed drilling program. Figure 3 shows the results of original Grid 2 and extension Grid 5. The mineralisation associated with the historic workings is evident as a low amplitude anomaly aligning along the northwest trend. Grid 2 was extended to the northeast to define the anomalous zones shown as drilling targets T4, T5, and T6 on Figure 3.
Figure 3
These chargeable zones align with the major northwest structure defined by the quartz ridge in line with T7. Athena is encouraged by the response in an area previously untested by historic surface prospecting and recent geochemical sampling. A Dipole-Dipole line was positioned over the best Gradient Array anomalism (Line 9400E in Figure 4) to map the vertical extents. The results of the chargeability and resistivity 2D inverted section have provided Athena with exciting new drilling targets. The resistivity high centred on 2625N correlates with the outcropping quartz associated with the northwest structure; however both the resistivity and chargeability anomalies around 2725N are untested and will be targeted in the upcoming drilling program. Grid 3 (Figure 5) was positioned within the main historical lead mining area at Kooline. The historical workings aligning along the edge of the 450m long anomalous chargeability response provided Athena with enough confidence to position a Dipole-Dipole line to test the vertical extents and orientation. Figure 6 shows an exciting chargeability anomaly located to the south of the existing workings which will be drill tested as a priority in the next field season. Figure 7 shows the results of the Gradient Array Grid 4 over the previously defined Gold zone. There are correlating resistivity and chargeability anomalism within the 25ppb gold contour. The previously announced gold auger geochemical sampling results are shown with respect to the chargeability response.
Figure 4
Figure 5
The five Gradient Array grids cover less than 15% of the area of known outcropping mineralisation and historic workings and have provided Athena with additional drillhole targets not previously defined by surface exploration. The Company is excited about applying these IP methods to test the remaining area which has not been explored with modern exploration techniques.
Figure 6
Figure 7
Planned Drilling Program
Athena has planned a 2000 metre reverse circulation (RC) drilling program to test targets identified by the soil geochemistry and previous exploration results.The documentation to obtain relevant departmental approvals has been submitted and the drilling scheduled to be completed during the next exploration field season.