Commonwealth Hill Iron Ore Project (South Australia)

Overview & Exploration

Background 

Apollo Minerals holds 100% interest in three Exploration Licences in the Commonwealth Hill area in central South Australia.

Location

The Commonwealth Hill tenements lie within the Gawler Craton and are centred approximately 90km to the north of Tarcoola in South Australia.  The area is highly prospective for a range of targets including iron ore, copper, gold and uranium.  The Olympic Dam, Prominent Hill and Challenger gold mines are all close to the project area as are a number of iron ore exploration projects.

Geology

The Company's Commonwealth Hill tenements encompass a number of aeromagnetic anomalies which were targeted for possible iron ore resources by the South Australian Department of Mines and Energy (SADME).  Three specific targets were identified for detailed work, being the Sequoia, Wirrida and Gina prospects.

 

At Sequoia, drilling defined an Inferred Resource of 22 million tonnes at 28.4%Fe, with weathering to 45m.  Drilling at Wirrida and Gina failed to locate encouraging iron mineralisation but it did enhance the prospectivity for nickel, copper, platinum-group elements and gold.

 

Apollo Minerals' main target is the Wirrida Complex which was identified as a strong positive total-magnetic-intensity (TMI) anomaly in data collected by the South Australian Department of Mines and Energy (SADME) in 1992-93.  This survey was flown on lines spaced at 400m and at a 75m flight height and is therefore suitable only for identifying broad trends and outlining the location of magnetic units.

 

SADME subsequently investigated the Complex to determine whether potential existed for significant iron ore resources.  In 1995-96 the strong TMI anomalies were followed up with ground magnetics, shallow reverse circulation (RC) drilling, and geochemical, petrological and physical analyses of rocks.

 

Regional Location of Apollo Minerals' Commonwealth Hill Project

 

 

 

Exploration Completed on Apollo Minerals' Tenements

Geophysics

The Complex again attracted attention for iron ore in 2009 when Apollo Minerals' then joint venture partner, Western Plains Resources Limited, commissioned ground magnetic and gravity profiles over the TMI anomalies.  Data was recorded on eight lines spaced at approximately 400m intervals, with station spacing at 10m for the magnetics and 50m for the gravity.

 

 

Location of ground magnetic and gravity profiles completed in 2009

 

The Company has received a report from Southern Geoscience Consultants Pty Limited (SGC) relating to the modelling of ground magnetic data over the Wirrida Complex which lies within Apollo's Commonwealth Hill tenements.

 

SGC has modelled the ground magnetic data to determine the location and orientation of magnetite rich layers within the Complex to assist in the design of an exploration programme to assess the iron ore potential.  Preliminary modelling indicates that the shallow RC drilling completed by SADME in 1995-96 did not intersect the magnetic source rocks and the magnetic susceptibility values recorded in the drill logs would not account for the TMI response observed in the airborne and ground magnetic surveys.

 

The SGC report noted that "The modelling of the ground magnetic data has demonstrated the potential for considerable intersections of magnetite rich layers and the inference of a near surface altered or weathered zone that could possibly contain iron-rich, non-magnetic mineralisation".

 

SGC has recommended a follow-up high resolution, low level airborne magnetic survey, with 100m-spaced lines at a flight height of 15-20m, as the next programme to improve definition of the target zones.

 

Previous work over the Wirrida Complex has also outlined the potential to host base metal and precious metal mineralisation associated with sulphide zoning within the layered intrusion.  This potential will also be assessed in the future with SGC recommending an airborne electromagnetic survey (AEM).