Located 80km north‐west of Rockhampton in Central Queensland, the Develin Creek base metals project hosts several copper-zinc-gold-silver volcanic hosted massive sulphide deposits and covers an extensive belt of underexplored prospective host rocks. Mineralisation comprises massive sulphide, stringer and breccia style copper-zinc-gold-silver deposits, hosted by basalts.

The Develin Creek deposits are of a style similar to those currently being mined by Sandfire Resources NL at DeGrussa and Independence Group NL at Jaguar-Bentley, which are both located in Western Australia. These types of deposits typically occur in clusters making them attractive exploration targets.

Drilling completed to date by Zenith at the Sulphide City deposit has returned results including: 5m @ 2.45% copper, 2.14% zinc, 0.4 g/t gold and 30.7 g/t silver and 3m @ 2.63% copper, 0.88% zinc, 0.5 g/t gold and 36.7 g/t silver supporting results from a diamond drill hole completed in 2011 that returned an intersection of 13.2 metres @ 3.3% copper, 4.0% zinc and 0.4g/t gold.

Massive bedded copper-zinc sulphide mineralisation remains open at depth beyond the main Scorpion deposit to the north and north-east, whilst bedded massive sulphide remains open ended to the northwest of the Sulphide City deposit (Figure 1). Incremental resource extensions are likely to the immediate north of the Window resource.

Image module

The Develin Creek project (Figure 3) contains a VMS copper-zinc deposit with an Inferred Mineral Resource (JORC 2012) of: 2.57Mt @ 1.76% copper, 2.01% zinc, 0.24g/t gold and 9.6g/t silver (2.62% CuEq) released to ASX on the 15th February 2015. Upside to resource grades are considered likely with Zenith RC hole twinning previous 1993 percussion hole returning significantly higher copper, zinc, gold and silver grades (300% to 700% higher).  Initial metallurgical testwork results show positive first stage “rougher” recoveries of 90%. The Company holds exploration permits that cover the highly prospective host rocks over 50km north – south.

The Sulphide City mineralisation consists of stockwork, disseminated and massive sulphide mineralisation (Figure 1). The main Sulphide City lens, outlined with a 1% copper equivalent cut-off, has a horizontal projection of about 400m x 150m. The lens varies from 2.5m to 29m in thickness, generally dips 25-30° west-northwest and has been intersected at depths between 80m and 200m. Better historic drill intersections include:

  • DDH-016 14.5m @ 0.6% Cu and 4.3% Zn (includes 2.5m @ 12.0% Zn)
  • DDH-044 11.3m @ 2.1% Cu, 5.9% Zn, 16g/t Ag & 1.21g/t Au
  • PD-052 15.0m @ 3.1% Cu, 2.3% Zn
Image module

Figure 1: Sulphide City Deposit – Cross Section

The Scorpion deposit, 500m south-west of the Sulphide City deposit occurs in a 400m x 200m zone in altered volcanic rocks. The sulphide body, 2.5m – 9.5m thick consists of brecciated massive sulphides and grades up to 6% Cu, 9% Zn, 43g/t Ag and 1g/t Au. Better historic drill results (previously reported) include:

  • DDH-001 21.6m @ 2.5% Cu, 1.5% Zn, 13g/t Ag & 0.5g/t Au (includes 16.2m @ 3.2% Cu, 1.6% Zn)
  • DDH-002 31.6m @ 1.5% Cu, 1.5% Zn, 15g/t Ag & 0.3g/t Au (includes 16.7m @ 2.1% Cu, 2.0% Zn)
  • PD-007 44.0m @ 1.6% Cu, 1.0% Zn, 8g/t Ag & 0.3g/t Au (includes 25.0m @ 2.6% Cu, 1.2% Zn)

The highly weathered Window mineralisation consists of a ~40m thick sub-horizontal supergene blanket of copper mineralisation at 50m depth within a wider zone of stringer style mineralisation. The location and style of mineralisation indicates that the Window Deposit may be the partially eroded footwall stringer zone to the nearby Scorpion massive sulphide lenses. Better historic drilling results from Window (previously reported) include:

  • PD-012 84.0m @ 0.8% Cu (includes 48.0m @ 1.2%)

New Snook Copper Prospect

Geological reconnaissance mapping and soil sampling has outlined a 25m wide zone of gossanous sedimentary (bleached and sheared) rocks over 150m of strike that occur as discrete units enclosed within basalt that are part of the prospective Rookwood Volcanics’ host sequence (ZNC ASX Release 13th May 2020).

The base metal and trace elements within the new rock sample returned highly anomalous results: 7.58% copper, 0.48g/t gold, 7.8g/t silver, 123ppm bismuth, 46ppm molybdenum, 28ppm antimony, 0.13% arsenic, 0.16% lead and 0.3% zinc.  These geochemical results are like those in rock samples taken at surface above the known copper-zinc volcanogenic massive sulphides (VMS) deposits further to the north where Zenith has defined JORC resources of 2.57Mt @ 1.76% copper, 2.01% zinc, 0.24g/t gold and 9.6g/t silver (2.62% CuEq) ZNC ASX release 15th February 2015.

Initial geological reconnaissance mapping and soil sampling has outlined a 25m wide zone of gossanous sedimentary (bleached and sheared) rocks over 150m of strike that occur as discrete units enclosed within basalt that are part of the prospective Rookwood Volcanics host sequence.

Further mapping, sampling and geophysical surveying is required to better define the Snook Copper target.