Abenab Trend - Christiana Mine

The Abenab Trend is marked by a series of V-Pb-Zn occurrences located near the contact between the Auros Shale and Maieberg Dolomites. The Abenab West and Okurundu mines are located on this contact position and represent the highest priority targets. Approximately 40km strike extent of this highly prospective trend lies within The Company’s EPL3543.

Numerous untested soil geochemical anomalies have been generated along the contact through systematic soil sampling and field mapping.

Christiana Prospect

The Christiana Prospect is the extension and unmined portion of the Abenab West mine, which was the largest historic mine located in Golden Deep’s Grootfontein Base Metal Project (Figure 1). The Abenab area historically produced 150,000t of Vanadium, Lead and Zinc concentrates. Production figures from Abenab West indicate that 88,000t of Vanadium, Lead and Zinc concentrates were produced from 540,000t of underground ore. The workings extend over 800m of strike and to a depth of at least 380m below surface.
 

 

Figure 1 - Simplified geology of the Abenab Trend

CHRISTIANA MINERALISATION

Recent Fieldwork by Golden Deeps’ geologists has shown that much of the upper two levels of the Christiana Mine are easily accessible for mapping and sampling. The 50ft level (15m below surface) and the 100ft level, (30m below surface) were sampled.
Three styles of mineralisation have been observed by Golden Deeps at Christiana:

• “Zinc Reef” - comprising high-grade willemite (zinc silicate) mineralisation,
• descloizite (lead vanadate) mineralisation, and
• disseminated primary sphalerite (zinc) and galena (lead) mineralisation.

The three styles of mineralisation appear to be closely associated with each other and are often intercalated.

The underground development is in very good condition and is safe to work in (Figure 8) Natural ventilation is also excellent as numerous vent rises to surface produce a natural air flow. With much of the necessary capital development is already in place, mining costs could be relatively low if the operation was to be reactivated.
 

Figure 2 – Cross cut on the 50ft level ending in descloizite-bearing breccia mineralisation. Note the stable ground conditions within the workings.

Underground Channel Sampling

The underground workings at the Christiana Mine consist of a series of ‘strike drives’ developed on 50ft (15m) spaced levels along a footwall shale contact. Cross-cuts are developed out to the north to access the interpreted ore position. The levels are linked to the surface by the centrally located Malcolm Shaft (Figure 4).

The mine workings were sampled by running channels or continuous rock chips along the backs (roof) of the cross-cuts. This provided a representative cross section through the mine stratigraphy and the mineralisation.

Approximately 320 metres of strike was sampled on the 50ft level (15m below surface). The channel samples have returned highly anomalous zinc, lead and vanadium mineralisation. This is extremely encouraging, given that many of the cross-cuts do not reach the interpreted ore position. As such, most of the sampling is located on the periphery of the main ore zone.

Some of the better results of the sampling are as follows:

50FT LEVEL

ABUG0012    11m @ 4.45% Pb+Zn (3.64% Zn and 0.81% Pb) and 0.27% V2O5
including           1m @ 14.27% Pb+Zn (11.2% Zn and 3.07% Pb) and 0.64% V2O5

ABUG0019    29m @ 4.53% Pb+Zn (4.22% Zn and 0.31% Pb) and 0.09% V2O5
including           6m @ 14.01% Pb+Zn (13.08% Zn and 0.93% Pb) and 0.28% V2O5

ABUG0020    15m @ 7.34% Pb+Zn (6.74% Zn and 0.60% Pb) and 0.19% V2O5
including           4m @ 18.80% Pb+Zn (18.36% Zn and 0.44% Pb) and 0.03% V2O5

ABUG0021    12m @ 5.36% Pb+Zn (3.08% Zn and 2.28% Pb) and 0.85% V2O5
including           1m @ 28.35% Pb+Zn (8.65% Zn and 19.70% Pb) and 7.02% V2O5

ABUG0022     44m @ 22.11% Pb+Zn (20.39% Zn and 1.72% Pb) and 0.53% V2O5
including          25m @ 33.39% Pb+Zn (31.06% Zn and 2.34% Pb) and 0.76% V2O5

ABUG0027        3m@ 15.93% Pb+Zn and 0.04% V2O5

ABUG0034      10m @ 10.39% Pb+Zn (9.51% Zn and 0.88% Pb) and 0.08% V2O5

ABUG0036      10m @ 4.96% Pb+Zn (4.44% Zn and 0.52% Pb) and 0.13% V2O5
including             3m @ 11.05% Pb+Zn (10.55% Zn and 0.50% Pb) and 0.00% V2O5





Figure 3 – 50ft level flitch plan showing channel sample locations and recent geological mapping.

CHANNEL SAMPLING

Sampling included all accessible underground development on three mine levels down to the 200ft level as well as open pits and surface exposures, identifying wide zones of high grade mineralisation The channel sampling spacing of 20m roughly matches the underground cross-cut spacing and provides a high level of sampling detail for the planning of future exploration programmes.

Approximately 500 metres of strike has now been effectively sampled at surface and on the 50ft, 100ft and 200ft levels. Almost every channel sample has returned highly anomalous zinc, lead and vanadium mineralisation.

The results are extremely encouraging as they indicate the following;

These results demonstrate the enormous potential of the Christiana Prospect.

Some detail of the better results of the channel sampling are as follows:

Surface

ABCS0008    47m @ 4.52% Pb+Zn (4.37% Zn and 0.15% Pb) and 0.02% V2O5
including        11m @ 15.30% Pb+Zn (14.94% Zn and 0.36% Pb) and 0.02% V2O5

ABCS0010    20m @ 3.84% Pb+Zn (3.03% Zn and 0.81% Pb) and 0.26% V2O5
including          5m @ 12.02% Pb+Zn (9.49% Zn and 2.54% Pb) and 0.88% V2O5

ABCS0023    16m @ 10.03% Pb+Zn (9.84% Zn and 0.19% Pb) and 0.02% V2O5

ABCS0024    10m @ 14.34% Pb+Zn (14.15% Zn and 0.20% Pb) and 0.01% V2O5
including          3m @ 33.58% Pb+Zn (33.28% Zn and 0.3% Pb) and 0.01% V2O5

Figure 4 - Ultra high resolution aerial photography overlain by new surface channel sampling results. Open pit outlines are shown in grey and interpreted mineralisation footprint in red.

Nosib Block

Figure 5 - Azurite mineralisation in underground exposure at Nosib Block Mine

The historic Nosib copper mine is located on the western end of the Abenab-Nosib Trend. Three levels of the historic Nosib Block copper/lead mine were accessed from the No2 Shaft during 2013 (Figure 6 and Figure 7).

Mapping and channel sampling has located high grade copper at the historic Nosib Block underground mine, which is located on the Abenab-Nosib trend, approximately 30km west of Christiana. The Nosib Block mine was developed on three levels, down to a depth of approximately 50m in over 200m of tunnels. The workings are contained within a fine grained sandstone unit showing signs of copper mineralisation. The Company’s geologists have re-opened the historic mine, and undertaken mapping and sampling of the extensive three level, two shaft mine system.

High grade copper, lead, vanadium and silver are hosted in a sequence of tillites, conglomerates and feldspathic sandstones (mine sequence) in contact with massive dolomites to the north (hanging wall) and basement granites to the south (footwall).

An important aspect of the mineralisation style at Nosib Block is the consistency in grade and width. It is therefore considered that Nosib Block has very good potential for future exploration success.

Most of the copper mineralisation remains in situ in the areas accessed so far. Level 1, 20m below surface, Level 2, 40m below surface and Level 3, 60m below surface have been accessed, mapped and sampled from No. 2 shaft. Broad zones of strong copper, lead, vanadium and silver have been encountered on all levels.

Channel sample results from Level 1 include:

• NOUG0001 6 m @ 9.30% Cu, 4.72% Pb & 7.92 g/t Ag
• NOUG0002 13m @ 2.32% Cu, 7.06% Pb, 6.85 g/t Ag
• NOUG0005 6 m @ 1.51% Cu, 10.59% Pb, 7.15 g/t Ag & 1.12% V2O5
• NOUG0004 9 m @ 1.37% Cu, 10.37% Pb & 14.4 g/t Ag
• NOUG0006 6 m @ 1.38% Cu, 4.19% Pb, 3.53 g/t Ag, 0.45% Zn & 1.09% V2O5
• NOUG0003 16 m @ 0.68% Cu, 6.58% Pb & 5.5 g/t Ag
• NOUG0010 13m @ 1.99% Cu, 5.56% Pb, 2.30% V2O5, 20.56 g/t Ga

Channel sample results from Levels 2 and 3 include:

• NOUG0012 8 m @ 2.86% Cu, 3.13% Pb, 5.56 g/t Ag & 0.56% V2O5
• NOUG0018 6m @ 2.50% Cu, 40.00g/t Ag & 16.8g/t Ga
• NOUG0020 9m @ 3.10% Cu, 11.33g/t Ag, 10.84% Pb, 3.12% V2O5 & 94.95g/t Ga

Several intersections contain anomalous levels of gallium, germanium and zinc, which show a similar metal association to the Tsumeb deposit located 26km to the northwest (30MT @ 4.3% Cu, 10% Pb, 3.5% Zn, 100g/t Ag and 50g/t Ge). This metal association has strong implications for the exploration and development potential of Nosib Block.

In excess of 1,600m of strike have been identified to date containing several high priority exploration targets, in particular the “Pinch Out” structure, 600m east of No 2 shaft and the No 3 shaft area, 400m west of No 2 shaft (Figure 5).
 

Figure 6- Plan view of the Nosib Mine workings. To the east the pinch out position is shown and the potential sandstone host is shown extending to the west.

The No 2 shaft and associated underground workings were recently surveyed. 3D models of the underground workings were built. This allowed the accurate positioning of the channel samples within the drives. 3D grade shells of the mineralisation have been generated (Figure 6). The 3D modelling shows high grade continuity from surface to over 60m below surface. The mineralisation remains open in all directions.

Figure 7– View looking WNW showing the underground workings in blue and 4% Cu Equivalent (CuEq)* 3D model in red. CuEq grade is calculated by combining the metals of interest based on their prices. In this case Cu% + (Zn% x 0.25) + (Pb% x 0.25) + (Ag ppm * 0.00625) + (V2O5% * 1.695) + CuEq%. It is used as a visualisation tool only and is required at Nosib Block due to the poly metallic and strongly zoned nature of the mineralisation. In this situation a CuEq grade provides a better picture of the overall geometry of the mineralisation than using copper grade on its own.