Golden Deeps intersects thick mineralisation at historic Nosib Block copper-vanadium mine

Initial drilling at the historic Nosib Block mine in Namibia has intersected thick intervals of copper mineralisation, including semi-massive copper-sulphides, for owner Golden Deeps (ASX: GED).

The diversified explorer confirmed that 13 of a total 15 reverse circulation (RC) holes completed for 958m encountered copper and carbonates of malachite, azurite, sulphides and tennantite.

The intersections included up to 33m of downhole mineralisation averaging 13m aggregate thickness, open at depth and along an 80m length.

One hole hit a 5m interval of semi-massive copper sulphides from 10m downhole (8.6m below surface).

High-grade discovery

Nosib Block was a high-grade, copper-vanadium discovery, located 16km west of Khusib Springs in Namibia’s Otavi Mountain Land.

From 1917 to 1920, the project’s No 2 shaft was developed on three levels to a depth of 120m but was never mined.

Golden Deeps’ geologists have since accessed the levels and taken underground channel samples from the drive walls.

The company is currently exploring between the levels to a depth of approximately 60m to 80m below surface and 80m along strike.

Drilling is testing the vicinity of previous underground channel sample intersections which included 6m at 9.3% copper, 4.72% lead, 7.92 grams per tonne silver; and 6m at 1.51% copper, 10.59% lead, 7.15g/t silver and 1.12% vanadium.

Golden Deeps said the Nosib Block mineralisation shows “good continuity and remains in-situ” primarily because the areas between the development drives were not mined.

Khusib Springs drilling

Nosib is the second key target area to be drill tested following completion of the first phase of drilling at the Khusib Springs high-grade copper-silver mine, which produced 300,000 tonnes at 10% copper and 584g/t silver from 1996 to 2003.

Golden Deeps drilled 10 holes for 331m at Khusib, targeting high-grade copper-silver mineralisation adjacent to historic stopes and up plunge from orebodies mined underground but not stoped to surface.

The company intersected copper mineralisation (malachite, azurite and tennantite) in two holes drilled into the up-dip extensions of the deposit near shallow surface workings.

Historic intersections in these areas include 4.5m at 35.19% copper, 3.67% lead, 2.23% zinc and 2090.91g/t silver from 30m; and 14m at 8.12% copper, 0.75% lead, 0.52% zinc and 385.06g/t silver from 37m.

Khusib Springs is considered analogous with the historic Tsumeb mine, 40km to the northwest, which produced 30 million tonnes of ore grading 4.3% copper, 10% lead and 3.5% zinc for 91 years from 1905.

Remnant mineralisation

Last year, Golden Deeps engaged South African consultancy Shango Solutions to validate previous exploration and mining data from Khusib Springs and delineate remnant copper mineralisation and strike extensions to the deposit.

Shango found zones of copper-silver mineralisation on the margins of the mined stopes as well as at depth, possibly left behind due to low grades in the prevailing low copper price environment.

Golden Deeps said the unmined ore is in the footwall between the developed levels at a depth of 50m and “could easily be mined by open pit”.

There is also potential for extensions to the defined ore zones along strike and down plunge.

Deeper targets – including the discovered but not mined Khusib Deeps – will be drill tested in future programs with the objective of finding copper-silver deposits of similar grade to historic results.