Koongie Park Project WA
Anglo Australian Resources NL 100%
The Koongie Park project, an advanced copper - zinc project consisting of 2 mining leases, two exploration licences and 15 prospecting licences is located 25km south-west of Halls Creek in the Kimberley region of Western Australia. The Company believes record base metal prices have profoundly improved the development economics of the project making it one of the better undeveloped base metal projects in Australia. The Company is proceeding with a Pre- Feasibility Study to maximise the value of the project and to facilitate its early development.
The project area covers several base metal prospects, which occur along a 15km contact of a volcano-sedimentary sequence. The area has been explored since 1972, with the discovery of several zinc-copper-lead-silver deposits, the main prospects being Sandiego and Onedin. Other known identified prospects include Atlantis, Gosford and Rockhole.
Upwards of $8.5 million has been spent by explorers on the project. Anglo Australian Resources has been associated with the property since 1989 and it is now wholly owned. In 1996-1997 Lachlan Resources N L, in joint venture with the Company, carried out extensive resource-definition type drilling and developed excellent geological and structural interpretations for both deposits. More recently Anglo Australian Resources NL, who has funded exploration on the project on a sole basis since 2002 and has completed an exploration program to collect material for metallurgical testwork, update the geological model, upgrade the resources to JORC standard and undertake an engineering assessment.
Regional Geology
The Koongie Park Project is located in the Halls Creek orogen formed in the Palaeoproterozoic due to the interaction of the Kimberley Craton to the northwest and the North Australian Craton to the east. The Palaeoproterozoic plutonic rocks and volcano-sedimentary sequence of the Halls Creek orogen have been defined as the Lamboo Complex. The Lamboo Complex has been divided in an Eastern, Central and Western tectonostratigraphic terrane and the Koongie Park Formation is located in the Central Terrane.
The Koongie Park Formation (1843+/-2Ma) postdates the Tickelara Metamorphics which consists of mafic volcanics, siltstones and mafic-ultramafic intrusions, thought to represent an oceanic island arc – backarc basin above a southeast-dipping subduction zone, or an ensialic basin along the margin of the Kimberley Craton above a northwest-dipping subduction zone (Sheppard et al., 1999).
In the project area, the Koongie Park Formation consists of a steeply dipping, highly deformed, sequence of spheroidal, felsic lavas, argillic sediments, volcanoclastics and various intercalated chemical sediments. In the south western part of the project area, the Koongie Park Formation is gradational into greywackes and sandstones similar to the Olympio Formation.
The sequence has been metamorphosed to green schist facies grade and four generations of folding have been documented. The first phase of isoclinal folding can often be recognised in the mineralised prospects and may have thickened the sulphide mineralisation. The main interpreted NE-SW trending double plunging antiform, with Rockhole and Onedin, is inferred to be related to an F3 fold event. Further to the south, at Atlantis and Mt Angelo prospects, NS trending F2 folds can be seen. Later shearing has affected the Sandiego and Onedin prospects and appears to have remobilised some of the sulphides.
The Koongie Park Formation consists of three members being from the base upwards, the Coolibah Tuff Member, the Camp Shale Member with a carbonate dominated lower portion known as the Mimosa Sub-Member and the Weldons Creek Lava Member.
Mimosa Sub-Member - hosts most of the base metal sulphide mineralisation and is characterised by its abundant carbonate content and consists of intercalated chert, chloritic schist, banded magnetite or pyrrhotite-chlorite rock, black shales (locally pyritic), impure dolomite, calc-silicates, with fine grained andesitic lavas and volcanoclastics. The carbonate at Onedin shows relics of glassy textures indicative of a hydrothermal system probably operating in a sea floor environment.
Camp Shale Member - forms the hanging wall to the mineralisation, and consists of a monotonous sequence of cleaved siltstones, and sericitic meta-siltstone which is carbonaceous at the base, and interbedded with fine grained andesitic to dacitic volcanoclastics and lavas, with rare thin (cm-dm) chert- BIF interbeds, which are locally mineralised.
Weldons Creek Lava Member - generally massive and coherent spherulitic dacite-rhyolite lava flows, aphyric to slightly quartz phyric, with minor thin banded iron formations and cherts. Interbedded siltstones and sandstones occur towards the top of the sequence.
Dolerite and granite bodies outcrop along the western and south margins of the Koongie Park prospect areas. In the east, granite intrudes the lower Coolibah Tuff Member of the Koongie Park Formation.
The Deposits
The Sandiego deposit is a steeply plunging tabular mineralised zone that has been drilled on 40m sections over a strike length of 120m to a depth of 500m, and remains open at depth. Its substantial potential is illustrated by the 1996 drillhole SRCD 7 roughly in the middle of the deposit which intersected 77m @ 1.65% Cu, 1.48% Pb. 9.7% Zn, 60.7 g/t Ag and 0.54 g/t Au (200-277m) and 20m @ 3.2% Cu, 0.05% Pb, 0.14% Zn, 16 g/t Ag and 0.31 g/t Au (292-312m). Recently metallurgical test hole SRCD24 confirmed the high tenor of the mineralisation within the middle of the deposit with intersections of 6.2m @ 2.14% Cu, 462g/t Ag, 41.6m @ 10.89% Zn and 29m @ 0.6% Cu, 621g/t Co.
The Onedin deposit is more complex in shape due to tight folding of the host stratigraphy. It is best described as mostly a rod-shaped plunging mineralised zone, but a high-grade horizontal component to the mineralisation is also recognised. Recently metallurgical test hole ORCD45, drilled down the plunge of the mineralisation, confirmed the geological model with outstanding intersections of 42m @ 0.7% Cu, 1.76%Pb, 15.68%Zn, 146ppm Co, 109g/t Ag (125 - 169m), 13m @ 1.93% Cu, 1.81%Pb, 13.46%Zn 143ppm Co, 146g/t Ag (178 – 191m) and 9m @ 0.56% Cu, 5.3%Pb, 7.65%Zn, 126ppm Co, 104g/t Ag (206-215m).
Resource Estimation
FinOre Mining Consultants (part of the CSA Australia Group) were commissioned by Anglo Australian Resources NL to undertake geological modelling of the Sandiego and Onedin Deposits and estimation of Mineral Resources to be reported in accordance with the JORC Code.
The Sandiego Mineral Resource was estimated using ordinary kriging applied to designated wireframes which were created at cut-offs of > 3.0% Zn and > 0.8% Cu. The Mixed Domain occurs where an overlap exists which contains both high-grade zinc and copper. Virtually all the Mineral Resource is classified as an Indicated Resource.
Table 1. Indicated and Inferred Resources at Sandiego
|
SUB TYPE |
LODE |
Tonnes |
Zn (%) |
Cu (%) |
Pb (%) |
Ag (g/t) |
Au (g/t) | |
|
|
|
Zinc Zone |
115,000 |
12.8 |
0.48 |
0.93 |
77.7 |
0.3 |
|
|
OXIDE |
Copper Zone |
86,000 |
0.94 |
2.23 |
0.48 |
70.5 |
0.3 |
|
|
|
Mixed Zone |
61,000 |
9.31 |
1.52 |
0.93 |
75.1 |
0.4 |
|
|
|
Total |
262,000 |
8.08 |
1.3 |
0.78 |
74.7 |
0.3 |
|
|
|
Zinc Zone |
375,000 |
9.74 |
0.49 |
0.71 |
35.5 |
0.3 |
|
INDICATED |
TRANSITION |
Copper Zone |
103,000 |
1.29 |
3.43 |
0.12 |
33.8 |
0.3 |
|
|
|
Mixed Zone |
131,000 |
9.34 |
1.53 |
0.46 |
48.5 |
0.3 |
|
|
|
Total |
609,000 |
8.2 |
1.21 |
0.56 |
38 |
0.3 |
|
|
|
Zinc Zone |
646,000 |
6.32 |
0.34 |
0.64 |
18.9 |
0.2 |
|
|
PRIMARY SULPHIDE |
Copper Zone |
696,000 |
0.97 |
2.39 |
0.07 |
6.7 |
0.3 |
|
|
|
Mixed Zone |
55,000 |
5.49 |
2.36 |
0.15 |
7 |
0.2 |
|
|
|
Total |
1,402,000 |
3.62 |
1.44 |
0.33 |
12.3 |
0.2 |
|
|
TOTAL |
|
2,280,000 |
5.4 |
1.3 |
0.5 |
26.4 |
0.3 |
|
|
|
|
|
|
|
|
|
|
|
|
|
Zinc Zone |
- |
- |
- |
- |
- |
|
|
INFERRED |
TRANSITION |
Copper Zone |
40,000 |
0.1 |
1.6 |
0.7 |
18.4 |
0.2 |
|
|
|
Mixed Zone |
10,000 |
4.4 |
1.3 |
0.2 |
6.7 |
0.2 |
|
|
|
Total |
50,000 |
1.3 |
1.4 |
0.6 |
15 |
0.2 |
Note differences may occur due to rounding errors
The Zinc Zone is open at depth. The Copper Zone is open at depth and possibly to the north.
The Onedin Mineral Resource was was initially estimated using ordinary kriging applied to designated wireframes which were created at cut-offs of > 3.0% Zn and > 0.8% Cu. Recently it has been recognised that a lower cut-off grade could be applied to reflect cut off grades that may be applicable to an open pit operation treating oxide and transition ore by leaching methodologies. The Mixed Domain occurs where an overlap exists which contains both high-grade zinc and copper. The entire Onedin Mineral Resource is classified as an Indicated Resource.
Table 2. Indicated Resources at Onedin - April 2008 update
CLASSIFICATION SUB TYPE LODE Tonnes Zn (%) Cu (%) Pb (%) Ag (g/t) Au (g/t) INDICATED OXIDE Zinc Zone 20,000 5 0.3 0.8 18.6 0.1 Copper Zone 940,000 0.8 0.9 1.2 18.1 0.2 Mixed Zone 270,000 3.7 1.0 1.3 24.9 0.1 Total 1, 240,000 1.5 0.9 1.2 19.4 0.2 TRANSITION Zinc Zone 460,000 6.7 0.2 0.9 22.2 0.1 Copper Zone 860,000 1.4 1.2 1.2 29.8 0.2 Mixed Zone 450,000 5.6 1.4 1.4 38.9 0.2 Total 1,770,000 3.8 1.0 1.2 30.1 0.2 PRIMARY SULPHIDE Zinc Zone 500,000 5.0 0.3 0.4 25.8 0.1 Copper Zone 130,000 2.6 1.9 0.5 27.2 0.1 Mixed Zone 70,000 5.3 1.9 0.6 47.9 0.1 Total 700,000 4.6