Following Aim-listed Tertiary Minerals’ previous announcement of favourable copper analytical results from sampling of core from historic drill hole RKN800, it has published a separate presentation with a focus on its Mushima North project, in Zambia.

The presentation highlights several targets that have been identified for further exploration.

The two highest-priority targets are Target C1, which is a prominent gravity high defined by BHP Billiton's Falcon airborne gravity survey with a coincident copper soil anomaly.

The wide, low-grade intersection of copper mineralisation recently announced from resampling core from drill hole RKN800 sits on the margin of the gravity anomaly making this an exciting target for follow-up, the company says.

Drill hole RKN800 pre-dates BHP Billiton's gravity survey. The C1 gravity anomaly was designated as an iron-oxide/copper/gold drill target by BHP Billiton, but never tested.

Another important target is Target A1, a 1.7-km-long copper soil anomaly with values up to 350 ppm copper (in portable X-ray fluorescence analysis) defined by 500 m spaced samples and supported by coincident arsenic and zinc anomalies.

This is a target for more conventional Copperbelt-style mineralisation, Tertiary points out.

Tertiary has designed a programme of follow-up exploration which will start with soil sampling to infill the First Quantum Minerals (FQM) 500 m spaced soil data and define drill targets.

Mushima North is one of five projects in Zambia where Tertiary is exploring for copper, and one of two projects which benefit from a technical cooperation and data sharing agreement with copper producer FQM. 

The project lies to the east of the high-grade Kalengwa mine, which was discovered by drill testing a coincident copper soil anomaly and gravity anomaly.

FQM has provided its extensive database for Mushima North, which includes airborne magnetic, electromagnetic and radiometric geophysical data, as well as 500 m spaced reconnaissance soil sample analytical results.

Additional historical data for the area was made available by JAW Consulting of Golden, Colorado, which was commissioned by the company to compile historical data and provide a detailed interpretation and targeting report.

The JAW targeting report has drawn on historical exploration from the 1970s onwards by Roan Consolidated Mines, African Minerals, Zamanglo Prospecting and BHP Billiton. The latter was exploring for iron-oxide/copper/gold deposits, a class of mineral deposit that includes some of the largest in the world, including Olympic Dam in South Australia.