THADUNA COPPER PROJECT

(Sipa 100% of 936 sq.km.)

Thaduna is situated in PaleoProterozoic rocks in the Gascoyne Region of Western Australia, and along with Ilgarari to the north, and Yerrida to the south, form part of Sipa’s search for copper deposits in Proterozoic rocks.

We have been exploring at Thaduna for seven years, based on the belief that this Region is capable of hosting major copper deposits, like Mt Isa in Queensland (255 million tonnes grading 3.3% Cu), and Nifty in Northwestern Australia (150 million tonnes grading 1.3% Cu).

In part, our area selection was based on the presence of the old copper mines in the district – Thaduna and Green Dragon (on small tenements excised from our ground) and Rooney and Ricci Lee – all of which we believe may be the ‘smoke’ indicating the presence of something ‘major’ nearby.

Thaduna is hosted by sedimentary rocks ascribed to the approximately 2,200 million year old Yerrida Basin, which is bounded to the west by the similarly aged Bryah Basin, and to the north by the Archaean Marymia Dome composed of granite with greenstone enclaves.

The Bryah Basin hosts the newly discovered DeGrussa high grade copper-gold deposits (10.7 million tonnes grading 5.1% Cu and 1.7 g/t Au) and the Peak Hill, Labouchere-Fortnum gold, and the Horseshoe Lights copper-gold, deposits further to the west.  As well the very large Magellan lead deposits, near our Yerrida Project to the south, are in the PaleoProterozoic rocks, whilst the Abbra polymetallic deposit to the northwest is hosted by younger NeoProterozoic rocs. The Marymia greenstones host the seven million ounce Plutonic and Marymia gold deposits.

One characteristic of ‘Great Mineral Provinces’ is that they host multiple commodity deposits, spread over long periods of geological time.

Exploration by Sipa over the last seven years at Thaduna has included geological mapping, detailed airborne magnetic/ radiometric surveys, soil – vacuum – auger – RAB shallow geochemical sampling, deeper RAB and RC drilling, a 1,017 metre diamond core hole (part funded by the WA Government) and an airborne VTEM electromagnetic survey, along with trial ground electromagnetic and Induced Polarisation geophysical surveys.

Thaduna Copper Project on Landsat

Since the Project commenced, Sipa has:

•          collected 3,976 shallow geochemical samples

•          drilled 3,164 RAB/Aircore holes for 52,091 metres

•          drilled 8 RC holes for 1,766 metres

•          drilled one Diamond core hole for 1,017 metres

During the 2010/2011 year, and to time of writing, we have:

•          collected 446 shallow geochemical samples

•          drilled 2,060 RAB/Aircore holes for 36,966 metres

•          drilled the deep Diamond drillhole

Very promising results have recently been received from the Enigma Prospect (Sipa ASX Announcements 19 August and 8 September 2011) in particular, and from the 1470 and Wash Copper Anomalies, along with encouraging results from a deep RC hole at Rooney, and several at Ricky Lee late last year. The figure below is a geochemical image showing copper distribution over part of the property, from shallow geochemical sampling, along with the location of Enigma, 1470 and Wash Anomalies.

Copper Image - part of Thaduna Project

It needs stressing that it is still early days at Thaduna and that there are still many copper geochemical anomalies to be drill tested, as well as large areas within the 1,000 square kilometre property to be systematically geochemically tested.

The geology at Thaduna, whilst still poorly understood, comprises dominantly clastic sedimentary rocks folded into a southwesterly plunging syncline, bounded to the north by the Archaean Marymia Dome along the Goodin-Jenkin Fault (a basin bounding feature). Though outcrop is poor, the overall structure is outlined very well by our recent VTEM, and older GEOTEM, surveys, which emphasise the electrically conductive Johnson’s Cairn black shale unit, both of which outline a synclinal closure just to the east of our ground. The shale is overlain to the west by the mafic-derived Thaduna Greywacke and underlain by coarse sandy clastics. Our deep diamond drill hole, which was sited on a discrete magnetic anomaly, intersected basaltic volcanics below 470 metres, previously unknown in this part of the Yerrida Basin. The old copper mines of the district are fault-controlled and are hosted by the Thaduna Greywacke. The Johnson’s Cairn Shale hosts the old CRAE Johnson’s Cairn Copper-Gold Prospect, which also has strongly anomalous Bi, Te, Ag, Sb, Mo & Ag.

Enigma Copper Anomaly

Enigma, which was first detected in shallow RAB holes (< 20 metres deep) with up to 0.4% Cu on north-south line 77,4500 mE, was followed-up by deeper (average 35 metres) overlapping angled RAB holes that outlined a significant copper anomaly in deeply weathered rock over 900 metres on that line. Minor secondary copper mineralisation was identified in three of the central holes on that line.  The figure above shows that lines 77,4500 mE and 77,5000 mE are at the western end of a six kilometre long northeasterly trending anomaly. 

Deeper Aircore drilling was conducted in July 2011, and intersected a ‘blanket’ of secondary copper mineralisation on 77,4500 mE (see below), and secondary copper and ironstone on 77,5000 mE (see below), as well as very strongly anomalous in Au, Pt, As, Mo, Pb, Sb & Te in THR 3,145, a single hole, on 77,4000 mE, about 500 metres northwest of the main mineralisation.

Enigma Prospect Drill section 77,4500mE

The secondary copper mineralisation is dominantly malachite, but with significant azurite (both copper carbonates). Minor chalcopyrite, a primary copper sulphide, was visually logged, as was native copper. Subsequent microscope (petrology and mineragraphy) work has identified chalcopyrite, along with supergene chalcocite, bornite and covellite.

The host rocks identified to date are dominantly very deeply weathered, conglomeratic to fine grained, sedimentary rocks, with a significant silica-sulphide veining component. Visual, and chemical analysis, shows a strong silica-dolomite. The ironstones on the eastern line are mainly interpreted as gossan, based on visual observations and multi-element analytical data.

Enigma Prospect Drill Section 77,5000mE

Enigma is a very large, and unusual, at least for Western Australia, occurrence of secondary copper. For instance, the original WMC 1980 Nifty secondary copper discovery of 30 million tonnes grading 1.1% was 1 kilometre long by 200 to 300 metres wide. Several of those could fit into the widely-drilled Enigma Prospect. Very importantly though, the primary source could be substantial.

Hole THR 2954, at the 1470 Anomaly, some 10 kilometres southwest of Enigma (see Copper Image, above), returned 30 metres grading 0.6% copper from 10 metres, including 4 metres at 2.4% copper from 24 metres. This hole extends a zone of significant copper reported in Sipa’s December Quarter 2010 ASX Report (30 metres grading 0.5% copper from surface, including 6 metres grading 1% copper from 9 metres) to more than 100 metres of strike.

Hole THR 3003, at the Wash Anomaly some 15 kilometres south southwest of Enigma, returned 30 metres of 0.15% copper from 36 metres, associated with strong carbon and quartz alteration, in bleached greywacke.

In addition, at Rooney in late 2009/2010, 80 metres of carbonaceous, weakly sulphidic, lode returned strongly anomalous copper from 224 metres, being:

•          19 metres @ 0.4% copper (with anomalous silver, arsenic, tellurium, bismuth & molybdenum) including:

•          5 metres @ 1.3% copper from 225 metres.

This intersection was about 200 metres down dip of several previously reported shallow intersections, in narrower though similar lode, like 14 metres of 3.8% copper.

The next phases of exploration at Thaduna will include extensive RC (and some diamond) drilling at Enigma, as well as at the 1470, and Wash Anomalies and at Rooney.