Predictive Discovery Ltd (ASX:PDI) continues to intersect broad, high-grade gold from resource definition drilling at its 4.2-million-ounce Bankan Gold Project in Guinea, raising the probability of lifting the current resource estimate.
A total of 1,266 holes for 42,877 metres have been drilled between April to the end of August 2022 in near-mine aircore and power auger drilling, and from August 1 to mid-September 2022 in infill diamond drill and reverse circulation (RC) drilling.
New deeper DD results 200 metres below the current NE Bankan pit shell showed further continuity of gold mineralisation and grade outside the current 3.9-million-ounce resource.
The aircore and auger drilling results, all within 3 kilometres of the current NE Bankan and Bankan Creek discoveries, have provided additional shallow and near-term deposit targets that have potential to add additional resource ounces to the Bankan Gold Project.
NE Bankan Drill Plan, including new DD and RC results (red) overlain previous results and high-grade zone, including the deepest DD hole completed to date (blue).
Rich geology
Predictive managing director Andrew Pardey said: “The drill results reported today are a combination of targeting the high-grade zone beneath the NE Bankan optimised resource pit shell, combined with the RC grade control drilling program adding to and improving the quality of Bankan’s 4.20million-ounce inferred resource. Also included is aircore and auger drilling, targeting potential nearby ‘feeder’ deposits.
“The company’s understanding of Bankan’s rich geology has accelerated substantially with 10 active drill rigs on site, up from four at the beginning of the year.
"Results to date correlate with our geological model of the orebodies discovered to date, whether it be the shallow oxide or the high-grade zone extending well below the current NE Bankan optimised resource pit shell.
"We remain on track to deliver on the 60,000-metre RC and diamond campaigns and have commenced the work on the detailed scoping study due to be completed in the second half of 2023.”
Diamond drilling
Drilling at NE Bankan is targeting the plunge extension of the high-grade shoot and upgrading the resource classification to indicated. The Bankan Project currently has an inferred resource of 79.5 million tonnes at 1.63 g/t gold for 4.2 million ounces.
There are currently 10 active drill rigs on site with four diamond, two multi-purpose diamond/RC, one RC, one aircore and two power auger drill rigs, all conducting various resource development and exploration programs across the Bankan Project.
Better results from six DD-holes totalling 3,022 metres include:
- 22 metres at 2.41 g/t gold from 68 metres and 7 metres at 7.11 g/t from 166 metres;
- 17 metres at 1.69 g/t from 582 metres;
- 30.52 metres at 3.55 g/t from 723 metres, including 9 metres at 7.98 g/t, and 16 metres at 6.14 g/t from 832 metres, and 7.6 metres at 3.17 g/t from 887 metres;
- 28 metres at 1.26 g/t from 229 metres;
- 1-metre at 60.2 g/t from 30 metres, and 15 metres at 1.75 g/t from 133 metres; and
- 22.8 metres at 3.52 g/t from 404 metres, including 6 metres at 7.48 g/t from 412 metres, and 14 metres at 1.58 g/t from 430 metres, and 8 metres at 1.81 g/t from 502 metres.
Cut core high-grade specimens.
Additional drilling has been planned up-dip and south along strike to follow up on the strong intercept.
RC drilling
RC drilling completed 77 holes for 6,181 metres to investigate the short-range variability of the high-grade mineralisation within the upper fresh and oxide horizons of the main shoot.
Results from this program will be used to determine the drill spacing required to convert the current inferred resource to the indicated category and provide input into the scoping study now underway.
Some of the better results include:
- 28 metres at 3.31 g/t gold from 33 metres;
- 45 metres at 2.31 g/t from 2 metres;
- 42 metres at 2.04 g/t from 33 metres;
- 27 metres at 4.51 g/t from 8 metres; and
- 18 metres at 4.98 g/t from 6 metres
More good news
A total of 109 shallow aircore holes for 5,312 metres returned several significant intercepts, namely 50 metres at 0.58 g/t, 12 metres at 1.24 g/t and 14 metres at 0.96 g/t. The results confirm the presence of the NE Bankan-style mineralisation on exactly the same structural setting within the tonalite.
Some 1,074 auger holes totalling 28,362 metres were drilled on the main prospects between the NE Bankan and Bankan Creek resources areas.
Infill drilling around the eastern footwall of the NE Bankan shear zone picked up gold anomalism along the main Mafic Basalt-Tonalite contact east of the current pit shell with 10 metres at 10.53 g/t and 6 metres at 1.3 g/t, indicating mineralisation is potentially on the contact heading southwest along the interpreted strike extension.
Keeping busy ahead
A new NE Bankan program for DD and RC drilling will be designed to deliver a high conversion of resources from inferred to indicated categories.
Six DD rigs remain on double shift, while a second EDM2000 deep hole rig is expected to arrive in the fourth quarter of 2022. The final 3,916 metres of the NE Bankan resource RC drilling program are expected to be completed in October.
Over at Bankan Creek, some 1,280 metres of RC drilling is expected to be completed in the first quarter of next year.
Work on the regional as well as the near-mine exploration program will also keep Predictive very preoccupied. The latter will include testing the near-resource surface prospects and infill aircore sections linking NE Bankan North southward to join with the NE Bankan northern pit mineralisation.