Gryphon Minerals - High Grade Drill Results - Phase 2 Drilling - Banfora
Burkina Faso focused gold explorer, Gryphon Minerals (ASX:GRY), has released shallow high grade drill intercepts from the Banfora Gold Project, including 21m at 3.9g/t Au and 14m at 4.0g/t Au. These results will feed into the CIL plant study, being driven by the merger with Teranga Gold Corp.
- Multiple high grade drill results received from phase one drilling completed during the May-June Reverse Circulation (RC) drill program at the Nogbele Deposit, Banfora Gold Project
- Numerous high grade drill results have confirmed the plunge potential and robustness of high grade gold domains at the Nogbele deposit including the following RC results from infill and extensional drilling:
Nogbele Nangolo Domain
21m @ 3.9 g/t from 50m in BNRC4804
14m @ 4.0 g/t from 16m in BNRC4807
5m @ 6.6 g/t from 42m in BNRC4806
7m @ 4.6 g/t from 5m in BNRC4808
Nogbele North Domain 4
2m @ 69.6.5 g/t from 74m (including 1m @ 130 g/t) in BNRC4591
2m @ 10.2 g/t from 52m in BNRC4594
2m @ 6.5 g/t from 85m in BNRC4572
2m @ 5.7g/t from 68m in BNRC4574
Nogbele West Domain
9m @ 2.7 g/t from 10m and 8m @ 12.9 g/t from 49m in BNRC4587
5m @ 2.0 g/t from 66m and 6m @ 3.2 g/t from 98m in BNRC4585
- Significant new strike extension highlighted at South-West Tahiti Zone with results extending known mineralisation a further 180 metres to the NorthWest along strike. Shallow oxide RC results include:
10m @ 1.1 g/t from 17m and 31m @ 1.5 g/t from 47m in BNRC4600
23m @ 1.9 g/t from 5m in BNRC4597
13m @ 1.1 g/t from 15m in BNRC4599
- Follow up drilling is underway with 2 rigs (1 RC rig & 1 DD rig) operating on double shift. Results will be made available at the earliest opportunity.
Gryphon Minerals Limited (ASX:GRY) is pleased to provide an update on its exploration activities at the Banfora Gold Project in Burkina Faso, West Africa. Drilling completed during May/June focussed on advancing the high grade lodes at the Fourkoura and Nogbele Gold deposits to potentially increase the reserve grade and provide additional reserve growth.
Steve Parsons Managing Director of Gryphon Minerals said “We are extremely encouraged by these latest drill results from the Nogbele deposit at the Banfora Gold Project. We have now commenced a resource and reserve conversion drill program which will be used to update the Feasibility Study for a Carbon In Leach processing plant. The recent placement by Teranga Gold Corporation has enabled us to fast track the drilling and engineering studies for completion early in 2017 with anticipated commencement of construction and development later that year.”
Nogbele Deposit RC Drilling Results
Results have now been received from all drilling completed during the May/June Reverse Circulation (RC) drill program at the Nogbele and Fourkoura Deposits. In total 827 metres of drilling was completed at Fourkoura (refer ASX 13/7/2016 for results1) and 3,470 metres of drilling at Nogbele. Current work is focussing on the refinement and extension of the high grade domains hosted within the project with the potential to improve the Carbon-In-Leach (CIL) economics and reserve inventory. The drilling will be incorporated into a new resource estimate due for completion to accompany the scheduled Feasibility Study for a CIL operation in first half of 2017.
The drilling program has successfully reinforced the geological model at the Nogbele-Nangolo, North and West Deposits and at the Fourkoura North Deposit area confirmed shallow high grade plunging mineralisation with potential to further extend known mineralisation at depth. Drilling has also highlighted the potential for a significant strike extension (>180m along strike mineralisation intercepted) of the Tahiti Pit at Nogbele South with material expected to be closer to the average grade of the current resource over downhole widths up to 30 metres.
Nogbele South Deposit-Tahiti Zone Strike extension
Nogbele South covers two parallel north-west trending structures that are host to a series of discretely plunging orebodies. Mineralisation at Nogbele South is generally hosted in an alteration of the host Nogbele Granite associated with pervasive micro-cataclasis of the host granite and strong Fe-carbonate, sericite pyrite alteration, generally devoid of quartz veining. Mineralisation is controlled by the interactions of sheared segments of mafic to lamprophyric dykes which have been resheared and carbonate altered. These zones are generally defined by a consistent grade tenor and a well defined plunge within the fault plane.
The Tahiti structure is the western of the two main faults and has been tested over approximately 1.6 kilometres. Mineralisation dips steeply towards the north-east and plunges steeply to the south-east within the fault.
Recent auger traverses testing beneath an untested gold in soil anomaly on the northern strike, defined a potential 200 metre long coherent +100ppb gold in saprolite anomaly extending known mineralisation. This anomaly has been followed up with shallow RC drilling intersecting significant alteration and veining consistent with known zones of mineralisation at the deposit. These new results included the following intercepts:
BNRC4600 10m @ 1.1 g/t from 17m and 31m @ 1.5 g/t from 47m
BNRC4597 23m @ 1.9 g/t from 5 m
BNRC4599 13m @ 1.1 g/t from 15m
BNRC4801 10m @ 1.1 g/t from 17m
Drilling at the prospect was terminated before the end of the planned program due to ground conditions causing frequent hammer blockages in the RC. A follow up program of 1,000 m of diamond drilling is currently being prepared at the prospect to convert the new zone into the resource inventory. Sample recovery weights and moisture content logging indicate the drilling difficulties have not materially compromised the reliability of the reported intervals. A total of 8 holes for 552 m of drilling were completed at Tahiti North.
Photo of previously announced diamond drilling at the Tahiti Structure, BNRCD0830 core in photo assays 11.35 g/t for the metre and is part of interval of 25m @ 1.6 g/t (refer ASX 24/7/20091). Fe-carbonate replacement of the original granite.
The new results extend known strike of the deposit 180 metres north of the previous resource boundary. The Tahiti North deposit was covered in the 2014/15 grade control drilling (refer ASX 6/5/20151) with results from this drilling to also be included in the resource update scheduled for H1/ 2017. There is a reasonable potential for these results to expand the current Tahiti Structure reserves with a reduced strip ratio associated with the extension in strike.
Selection of significant results form 2014 grade control drilling not included in the current public resource:
OPRC3406 19 m @ 6.3 g/t from 7m
OPRC2862 16m @ 6.8 g/t from 7m
OPRC2838 25m @ 3.4 g/t from 1m
OPRC3425 18m @ 4.3 g/t from 12m
OPRC3428 20m @ 3.3 g/t from 0m
OPRC3426 24m @ 2.4 g/t from 6m
OPRC2863 12m @ 4.0 g/t from 0m OPRC2846 17m @ 2.8 g/t from 17m
Refer to figure 3 below for a plan of the location of the new drilling relative to the 2013 CIL Definitive Feasibility Study Pit outline design (refer ASX 7/3/2012, 6/5/20151).
Nogbele- Nangolo Deposit
The Nangolo Zone is located only 2 kilometres west of the proposed CIL plant site and is situated in the major Northwest trending structural corridor that is associated with significant mineralisation within the central Nogbele Granite. Nangolo itself is hosted within the adjacent pluton to the Nogbele Granite and is tonalitic in composition.
Mineralisation at Nangolo is associated with sericite, carbonate, pyrite alteration of the Nangolo Tonalite with significant quartz carbonate veining hosting the higher grades. Mineralisation is characterised by discrete high grade tenor with visible gold observable in the vein material and forms an east trending main zone currently intercepted over 400 metres of strike. The mineralisation is hosted in an east-west linkage between two north-west trending fault segments. This is a very similar structural setting to the bulk of the lode style mineralisation within the adjacent Nogbele pluton.
Recent drilling focussed on infilling the interpreted up-dip and down dip plunge of the high grade shoot and testing footwall structures in the eastern pit area. A total of 12 holes for 942 m of drilling was completed at Nangolo.
Currently reported results from the RC drill program included:
BNRC4804 21m @ 3.9 g/t from 50m
BNRC4807 14m @ 4.0 g/t from 16m
BNRC4806 5m @ 6.6 g/t from 42m
BNRC4808 7m @ 4.6 g/t from 5m
BNRC4812 10m @ 2.4 g/t from 23m
BNRC4816 9m @ 2.6 g/t from 94m
The recent results from Nangolo are summarised on the long section shown in Figure 5, results have reinforced the interpreted high grade shoot and indicate potential for further in pit resources below the intercept in BNRC4816 (9m @ 2.6 g/t gold) where mineralisation is steepening. This suggests previous step back drilling has failed to intercept the main ore lode. Importantly recent results indicate the potential to improve the current resource grade with greater selectivity applied to the main ore shoot which has been very robust in drill testing.
Previously released results from the Nangolo Deposit include: (refer ASX 16/3/2009, 21/8/2009, 23/3/20101):
BNRC0574 9m @ 9.9 g/t from 39m
BNRC0959 20m @ 3.0 g/t from 69m
BNRC0784 8m @ 8.7 g/t from 108m
BNRC1201 7m @ 11.2 g/t from 89m
BNRC1207 8m @ 10.1 g/t from 67m
BNRC1231 16m @ 5.3 g/t from 82m
Further diamond drilling is planned for phase 2 follow up to be undertaken in the current program. The drilling will be designed to test for mineralisation down plunge, provide further geological control on the main fault and to test the central area between the two ore shoots.
Long section of the eastern main ore shoot at Nangolo, the western high grade shoot is around 75 m to the west of the displayed long section with a total strike of 400m. Intersections are annotated from new drilling marked by the stars and existing drilling as circles as metres of intercept/average grade of intercept. The main plunge of the ore shoot is associated with a steepening of the ore shoot as indicated by the structural contours and the main lode is truncated to the east by a North-west trending fault.