This is a result of the company’s on-going near mine reverse circulation (RC) drilling programme, which is intended to identify new resources and increase the geological confidence of the resource base with the goal of enhancing the medium term economics of the mine.
During the last half of 2015, near mine exploration activities continued to build on the results published in the company’s September 18, 2015 press release, with the main focus of RC drilling activities being in the Namoya Summit and Filon B deposits, including infill and step out drilling from previous drill holes.
Additionally, exploration drilling was carried out in the newly-discovered Namoya Summit hanging wall and Filon C targets.
Interim programme update
During the interim period following the September 18th press release, 54 RC drill holes totalling 4 681 m were drilled at Filon B, Namoya Summit Footwall zone, Namoya Summit Main zone, Filon C and Namoya Summit Hanging Wall zone. The significant mineralization intersections from the interim programme include the following:
Namoya Summit & Filon B
- Hole NRC-091 intersected 10 m grading 2.23 g/t Au from 67 m,
- Hole NRC-092 intersected 42 m grading 2.29 g/t Au from 51 m,
- Hole NRC-093 intersected 7 m grading 2.05 g/t Au from surface (2 m of void from 7m to 9 m),
- Hole NRC-107 intersected 15 m grading 2.44 g/t Au from surface (and 5 m of void from 15 m to 20 m),
- Hole NRC-108 intersected 5 m grading 3.23 g/t Au from 17 m,
- Hole NRC-109 intersected 10 m grading 18.48 g/t Au from 34 m, including 1 m of void from 38 m,
- Hole NRC-112 intersected 6 m grading 17.65 g/t Au from 82 m,
- Hole NRC-115 intersected 13 m grading 2.21 g/t Au from 98 m.
Namoya Summit Hanging Wall and Filon C
- Hole NRC-100 intersected 13 m grading 3.41 g/t Au from 12 m,
- Hole NRC-129 intersected 29 m grading 3.84 g/t Au from 52 m,
- Hole NRC-134 intersected 16 m grading 4.16 g/t Au from 34 m,
- Hole NRC-137 intersected 8 m grading 2.27 g/t Au from 57 m.
Commenting on the results at Namoya John Clarke, president and CEO of Banro Corporation, said: “These results continue to indicate the upside potential of the Namoya Summit deposit and demonstrate potential at Filon B area which is known to host very high grade mineralisation.
“We will continue to pursue detailed and careful evaluation of the Namoya Summit deposit, especially at Filon B and the newly discovered Hanging Wall zone, to ensure that we understand these structures and to delineate significant additional resources. These results, together with the previous results, have provided the necessary information to assist with Mineral Resource and Mineral Reserve upgrades at Namoya which are planned for the second quarter of 2016.”
The RC drilling program was undertaken using an in-house Prospector rig. A total of 54 RC holes averaging 87 m were completed for a total of 4 681 m to generate 4 681 RC samples.
All RC samples for assaying were taken consistently at 1 m intervals and were riffle split with one-half of the sample placed in sealed bags and sent to the company’s on-site sample preparation facility.
The samples were then pulverized down to 90% passing 75 microns. Approximately 150 g of the pulverized sample was then sent to the on-site SGS Laboratory (which is independent of the company) where the samples were analysed for gold by fire assay using a 50g charge.
Progress Summary of the drilling programme
After the successful drilling campaign, the mineral resource team will incorporate the drill results from these additional near surface zones into the Namoya Summit reserve with the aim of delivering an enhanced production profile for the commencement of mining at the Namoya Summit in the second half of 2016.
A total of 38 RC drill holes representing 3 324 m were drilled at Filon B, Namoya Summit Footwall zone, and Namoya Summit Main zone. The resource area has been interpreted to have a strike length of 400 m.
It is open to the northwest and southeast, with multiple gold bearing lodes that extend to a depth of 65 m, and exhibits a pinch and swelling characteristic; widths between 2 m and 30 m down-dip.
A northwest – southeast trending zone of new mineralisation (Namoya Summit Hanging Wall zone) has been delineated about 400 m to the northeast of Namoya Summit Main zone. Mineralisation was discovered by trenching and auger drilling over a strike length of almost 700 m and followed up by RC drilling. A total of 11 RC drill holes, representing 861 m have been completed in the area. Significant mineralisation was intersected including holes NRC129, NRC134, and NRC137. Follow up drilling will be undertaken to fully evaluate this new hanging wall mineralized zone.
Within the Namoya Summit Main pit shell, a new east-west mineralized zone, Filon C, was also discovered by trenching and auger drilling. Five RC drill holes totalling 431 m have been completed in the area. Significant mineralisation intersections include hole NRC100. Follow up drilling will be undertaken to fully determine the strike extension of this new mineralised zone.