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GRYPHON BANFORA DEPOSIT

 

 

BANFORA DEPOSIT

Project Location and Access

The project is located in the south-west of Burkina Faso, West Africa, in a major gold producing district.

It is easily accessible by paved road to the closer town of Banfora via Bobo Dioulasso (located 100km paved road away).

 

Bobo is linked by a further 360km paved road to Burkina Faso’s capital city Ouagadougou. The main deposit Nogbele is at 4 km about of the Ivory Coast border.

The project is owned 100% by Gryphon Minerals and contains 6 continuous exploration licenses covering approximately 1,200 square kilometers.

 

 

HISTORY

.  Ancients: Gold working site was present in Fourkoura prospect since the times of the Mali Empire.
.  Years 60 to 70: regional prospection and mapping by BRGM
.  BUMIGEB later do regional and detailed soils sampling for base metals exploration and identified gold anomalies at Fourkoura and Nogbele
.  WMC started exploration work on the license from in 1995. The loumana license was granted to WMC Resources in April 1996.
.  Loumana assets was transferred to resolute in April 19999:  Resolute(1999-2004) which does exploration by Geophysics, RAB and RC drilling identified a deposit at Nogbele.
.  Resolute abandoned the Loumana license in 2004 and a new exploration license was granted to local company called Sanembaore Sarl (2004+)
.  Gryphon Minerals come in in 2005 by JV with Sanembaore and start aggressive exploration drilling.
.  December 2010 Gryphon Minerals announce a new discovery at the Samavogo Prospect.
.  March 31, 2011: Gryphon announced inferred resource estimate at the Banfora Gold Project of 29Mt @ 2.1g/t for 2 million ounces.
.  September, 13, 2011: a new gold discovery at Stinger.
.  Resources update on 09-Jul-2012 lead to more than doubling the project’s resource estimate to 4.5 million ounces of gold.
.  The company announced in January 2013 the results of the “BFS” which demonstrate the viability of the Banfora Gold Project. BFS supports an estimate of virgin ore reserves of 1.05 Moz gold and 4.9 Moz resources for the whole Banfora project.

 Project Geology

The banfora project his hosted by the Birimian age Loumana greenstone belt within Burkina Faso. This band of Birimian terrains is constituted geologically of: Intermediate to basic volcanics formations (Basaltes, Andesites) intruded by small granodiorite and gabbro units plus volcanoclastics and sedimentary formations called epizonal schists. Conglomerates levels, quartzites and cherts levels are present as well.

The project area is characterized by a large central volcano sedimentary domain mainly pyroclastic in composition, flanked by two sub-parallel bands of volcanic and hypovolcanic complex.

The first complexe is composed of intermediate to basic metavolcanic Iava intruded in some areas by granitic and gabbro diorite bodies. Lavas are sometimes elongated or totally schistosed in shear zones. The second complex is mainly characterized by the importance of massive intrusions (gabbro) directly associated to granitoid.

The Magmatic breccia complexes with associated pyroclastites-epiclastites covers the center and are made of magmatic breccia with rhyodacitic, andesitic blocs and fragments cemented by a dioritic matrix, or dacitic to rhyodacitic tuffs. Epiclastic rocks are characterized by graphites and tuffites.

 Syn-Tardi events intrusions comprises Amphibole and biotite rich Granidiorite. These are very equigranular massive intrusive in the inner zone, deformed on the edges and mainly conform to schistosity affecting the host volcanic and hypovolcanic rocks. Pink biotite rich granite and Pink granophyre are forming circular intrusive bodies.

- The Gneissic set on the eastern area constitute the great sets peri green rocks belt.

- Major Accident: NNE – SSW: The permit is crossed by a deformation corridor called Fourkoura-Kangoura shear zone. The deformation is brittle to ductile-brittle and develops a dominant schistosity. This zone is characterized by the importance of scattered quartz floats that could come from quartz veinlets in schistosed plans or flat veins.

DEPOSIT TYPES

4 different deposits within 20km radius area constitute the Banfora project resources.

-The Nogbele Deposit is associated with major extensional zones around the northern margin of the Nogbele  granitoid. Mineralization is wrapping around the nose of the Nogbele granodiorite into the surrounding sediments and mafic units with multiple parallel and sub‐parallel zones and lode quartz veins.

-The Fourkoura deposit: is hosted within the more competent zones of a differentiated dolerite and adjacent felsic intrusion which has silica pyrite alteration.

-The Samavogo deposit and the Stinger deposit are structurally controlled deposits located at or in the vicinity of a sheared contact of granitoid with volcano sedimentary package.

MINERALIZATION

The Nogbele Deposit is associated with major extensional zones. It is controlled by two mineralizing structures giving two mineralization orientations:E-W trending zones and NW-SE trending zones.

-         The E-W mineralized zones consist typically of multiple sub‐parallel zones of broad hematite and / or magnetite, silica and pyritic alteration, sericitic schist’s and lode quartz veins. Mineralization is wrapping around the nose of the Nogbele granodiorite into the surrounding sediments and mafic.

-         The NW-SE mineralized zones are shear hosted with little or no quartz veining and strong to moderate hematite, carbonate, sericite and pyritic alteration. These zones are typically higher grade.

Gold is associated with quartz and sulphides basically pyrite. It is also disseminated in pink granite with biotite.

 The Fourkoura Deposit is 7 kilometres from the Nogbele Deposit and is located on the intersection of a major shear corridor and a zoned dolerite intrusive.

At Fourkoura gold mineralization is associated within single and multiple sub parallel sheers with intense silica, iron carbonate, magnetite, pyrite alteration and quartz veining within the dolerite and a felsic intrusive adjacent to the Fourkoura Dolerite.

The Samavogo Deposit is located approximately 20 km to the north-east of the Nogbele Gold Deposit

The mineralisation is over 4,000 metres of a major regional shear zone and trends in a SW-NE direction and is associated with pyrite, sericite, hematite, carbonate and silica alteration within garnet schist and sheared volcanic

Stinger deposit is a new and significant north-east trending mineralized corridor.

Mineralization occurs as multiple stacked zones of shallow mineralization, associated with silica flooded and albite altered hematite dusted intrusive and sediments with fine grained disseminated pyrite and pervasive sericite alteration. Occasional minor milky veins and visible gold are present.

Mineral Resource and Mineral Reserve

The gold resource estimate completed at Banfora Gold Project has been completed by CSA Global based in Perth, Western Australia. Estimation has been conducted in compliance with the N43-101 and JORC code of reporting.

Source: ASX announcement on 31/01/2013

Resource estimate at 0.5 g/t cut off.

Deposit

Category

Tonnage

Grade

Contained Metal

(Mt)

(g/t)

(MOZ)

Total Banfora Gold Project Measured

6.3

1.5

0.31

Indicated

65.9

1.5

3.09

RESOURCES

Total  M & I

72.3

1.5

3.4

0.5 lower cut

Inferred

39.3

1.2

1.49

Total  resources

112

1.4

4.89

Total Banfora Gold Project Proven

2.7

1.77

0.16

RESERVES

Probable

14

1.98

0.89

Total  reserves

16.7

1.95

1.05

NB: Most of the figures are modified from company public data

www.gryphonminerals.com.au

 

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