Thaduna Drilling Progress – Enigma Copper Anomaly
- Shallow angle RAB holes outline 900 metre wide anomaly – with up to 27 metres grading 0.3% Cu
- Deeper Aircore drilling, in progress, intersects copper carbonate mineralisation in most holes – below the anomaly described above, and extending it to 1.3 kilometres wide
Sipa is pleased to report the final analytical results from the recent May-June RAB/Aircore drilling programme, as well as visual results from Aircore drilling, which has recently commenced, at the Enigma Copper Anomaly (see Figures 1 to 3). Two, potentially very important, outcomes are:
- a line of 25 angled holes, sited to follow-up wide-spaced shallow vertical holes previously returning up to 0.4% Cu (see Sipa’s 20 June 2011 ASX Announcement), returned highly anomalous copper (for example 27 metres grading 0.3% Cu) over 900 metres width (see Figure2)
- a line of deeper, vertical Aircore holes presently being drilled has now returned visual copper carbonate mineralisation (mainly malachite) over 1.3 kilometres width (see Figure 3). Analytical results are awaited
These developments at Enigma are considered a major step forward for our exploration at Thaduna -particularly given the extent of the visually recognised copper mineralisation.
The results are the product of systematic, iterative exploration – that is, anomalies detected in wide-spaced shallow RAB holes; then followed-up by traverses of angled RAB holes; leading to the current deeper Aircore drilling.
Our challenge is now to find the ‘primary’ source of mineralisation within the very large Enigma Copper Anomaly.
Analytical results have now been received from the last 128 RAB holes of the May-June drilling programme at Thaduna. Significant copper has been intersected at the Enigma, 1470 and Wash Anomalies.
Importantly, the latest results from the 77 4500 East traverse of angled RAB holes at the Enigma Anomaly have extended the width of this Anomaly, from the 600 metres reported to the ASX on 20 June 2011, to 900 metres. These new results are presented in Table 1 and are shown on Figure 2.
Even more importantly, visual logging of 100 metre-spaced vertical Aircore drilling that recently recommenced at Enigma, has recorded secondary copper mineralisation (dominantly the copper carbonate malachite), as a ‘blanket’ beneath the angled RAB traverse described above, over some 1.3 kilometres of width, as shown on Figure 3. This copper mineralisation generally comprises ‘sparse to moderate’ malachite chips in deeply weathered ‘powdery’ rock, with occasional ‘abundant’ malachite intervals. Alteration in
these deeply weathered rocks includes silicification, oxidised (and rarely fresh) sulphides, limonite and clay minerals.
Hole THR 2954, at the 1470 Anomaly, some 10 kilometres southwest of Enigma , returned 30 metres grading 0.6% copper from 10 metres, including 4 metres at 2.4% copper from 24 metres (see Figure 1 & Table 1). 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
Hole THR 3003, at the Wash Anomaly some 15 kilometres south southwest of Enigma, returned 30 metres of 0.15% copper from 36 metres (see Figure 1 & Table 1).
Aircore drilling continues at the Enigma Anomaly, on the traverse of previous angled RAB hole 500 metres east of the 77 4500 East traverse just drilled.