Kaskara Copper-Lead-Vanadium Prospect
The Kaskara prospect lies on the Lucas Post Trend on EPL 3542 (SBR 70%). Kaskara was initially targeted in 2009, and was the product of a dedicated program of project generation and prospecting.
Initial exploration outlined an area of outcropping mineralisation covering over 900 metres of strike and hosting a number of high-grade base metal gossans that returned results of up to 23% copper, 35% Lead, 34% Zinc and 3% Vanadium. It is important to note that Kaskara shows many structural and mineralogical similarities to the nearby Tsumeb copper deposit, (24.9 Mt @ 5.5% Cu, 11.8% Pb and 171 gpt Ag).
RC drilling on the peak of the Kaskara hill, next to the Harasib III pit, January 2013
Drill testing of Kaskara has proven challenging due to the nature of the mineralisation in the oxide zone above the identified sulphide geophysical target at depth. The oxide mineralisation at Kaskara is particularly fine grained and is easily washed away by the addition of water during diamond drilling, resulting in little or no return of sample. This has resulted in Sabre utilising dry drilling techniques.
Gossan & Pit Sampling
Outcropping oxide mineralisation at Kaskara occurs in gossans throughout the mineralised corridor, covering at least 900 metres of strike, but the mineralisation in the Harasib III pit is located 200 metres outside of this corridor. Importantly the Harasib III mineralisation coincides with the southern edge of the extensive IP anomaly detected at depth below Kaskara.
Channel sampling of mineralisation at the base of the Harasib III pit has returned high-grade lead-vanadate mineralisation including:
KKUG0023 21 metres @ 4.79% Lead, 2.00% V2O5 and 0.21% Copper
KKUG0024 4 metres @ 8.71% Lead, 3.69% V2O5 and 0.47% Copper
These results show that the eastern vertical wall of the Harasib III pit is highly mineralised to the base of the workings, 18 metres below surface, and is expected to continue vertically downwards before grading into sulphide mineralisation at depth.
The old headframe at Kaskara, used to access the underground workings on the northern side of the deposit.
In 2011 Sabre discovered previously unknown and inaccessible underground drives within the mine workings at Kaskara. Broad zones of massive Pb-V-Cu mineralisation were encountered in this network of underground workings.
Some exceptional results were returned from channel sampling of these drives, including:
KKUG0003 13 metres @ 5.59% Lead, 2.31% V2O5 and 0.32% Copper
KKUG0019 22 metres @ 4.16% Lead, 1.81% V2O5 and 0.26% Copper
The massive mineralisation in the oxide zone occurs as continuous sub-vertical shoots extending from surface to a depth of more than 45 metres below surface. This sampling shows that the mineralised body is thickening with, and remains open at depth.
Diagrammatic/ Idealised cross-section of Kaskara (Harasib III pit on the peak of the hill).
RC Drilling 2012-13
The nature of the mineralisation at Kaskara prevents effective diamond drilling in the oxide zone. This style of oxide mineralisation is largely peculiar to this area of southern Africa and is also observed in other locations in the OML associated with significant sulphide ore bodies such as the Tsumeb copper deposit to the north and the Abenab & Berg Aukas Lead-Zinc deposits to the east.
Sabre sought advice on the drilling of this mineralisation, with the aim of testing the identified sulphide target at depth. The mineralised oxides must be drilled dry utilising appropriate levels of air pressure and lift to keep drill holes dry and ensure sample return. A highly experienced and respected local drilling company, specialising in Reverse Circulation (RC) drilling was contracted to undertake the initial RC drilling program at Kaskara and commenced drilling early in the fourth quarter of 2012.
The Reverse Circulation (RC) drilling at Kaskara commenced in late October 2012. A total of thirty four holes (KKRC0018-0051) were drilled across the outcropping mineralised zone. The results show that Sabre has successfully intercepted broad zones of mineralisation at Kaskara, that extend to depth.
Significant intercepts included:
KKRC0020 19.00 m @ 1.01% Pb+Zn, 0.26% V2O5 & 0.10% Cu from Surface
And 10.00 m @ 1.28% Pb+Zn, 0.09% V2O5 & 0.05% Cu from 114.00 m
KKRC0027 12.00 m @ 2.41% Pb+Zn, 0.73% V2O5 & 0.24% Cu from 31.00 m
KKRC0028 11.00 m @ 1.10% Pb+Zn, 0.21% V2O5 & 0.06% Cu from 56.00 m
KKRC0031 18.00 m @ 1.16% Pb+Zn, 0.27% V2O5 & 0.09% Cu from Surface
And 21.00 m @ 1.09% Pb+Zn, 0.21% V2O5 & 0.07% Cu from 107.00 m
KKRC0032 35.00 m @ 1.17% Pb+Zn, 0.11% V2O5 & 0.31% Cu from 157.00 m
KKRC0035 16.00 m @ 1.01% Pb+Zn, 0.28% V2O5 & 0.07% Cu from 155.00 m
KKRC0036 23.00 m @ 1.17% Pb+Zn, 0.11% V2O5 & 0.06% Cu from 190.00 m
And 10.00 m @ 1.14% Pb+Zn, 0.34% V2O5 & 0.15% Cu from 234.00 m
KKRC0038 16.00 m @ 4.28% Pb+Zn, 1.30 % V2O5 & 0.26% Cu from 54.00 m
KKRC0045 10.00 m @ 5.39% Pb+Zn, 1.57% V2O5 & 0.16% Cu from 19.00 m
A number of drill holes were targeted below the oxide zone at Kaskara to test the IP anomaly identified at depth. These holes extended below 200 metres vertically, with the deepest hole (KKRC0033) drilled to a vertical depth of over 280 metres. However, these deep holes continued to intersect friable oxide mineralisation, which caused significant problems with drill holes collapsing thus preventing the holes from being completed. Drilling did not fully test the source of the IP anomaly. These deeper drill holes have now been ‘cased’ and will be used to undertake down hole geophysics.
Kaskara is a large mineralised system, including extensive surface mineralisation and significant mineralised intercepts in drilling. The deep IP target at Kaskara remains only partially tested and requires down hole geophysics, together with digital modelling, to help better target the source of the anomaly at depth prior to exploration recommencing on the prospect.