Redan (Earning 51%) Burta (100%)- NSW Hawsons Iron Project

The Hawsons Iron Project area is located about 60km south of Broken Hill. It is relatively close to the major Australian E-W railway line and Adelaide - Broken Hill road as shown. A high tension power line  runs about 30km east of the project. The city of Broken Hill is a mining town with a good mining culture, strong workforce, air, road and rail connections to Adelaide and Sydney.

The tenements cover an extensive airborne magnetic anomaly. The project area is covered by two exploration tenements (Figure 1). To the south, Burta (EL 7208) is 100%-owned by Carpentaria. The Redan tenement (EL 6979) to the north is a joint venture (JV) with Perilya Broken Hill Limited (ASX: PEM) where Carpentaria can earn a 51% interest initially with the expenditure of $825,000 (Refer to December 2008 ASX Quarterly Report for detail).

Figure 1 : Location

Review of previous work by Carpentaria indicated that in 1960, Enterprise Exploration Co. Pty. Ltd. (the precursor to CRA Exploration) undertook channel rock sampling over a large area of outcropping NeoProterozic rocks interpreted to be components of the Braemar Ironstone (Yudnamunta Subgroup of the Adelaide Fold Belt) located to the east of Hawson’s Knob. Iron (Fe) concentrations ranging from 36.4% to 49.1% in relatively fine grained banded magnetite-hematite-quartz rocks were reported. Enterprise did not undertake any further work at the prospect.

Geological mapping, Niton, XL3t, X-ray Fluorescence (Niton XRF) quantitative micro-analyser  analysis, and multi-element geochemical sample locations  within the outcropping section of  iron formation  are shown in Figure 2. These results are comparable and suggest the iron concentration of the exposed iron formation increases northward towards the concealed high-amplitude core of the regional magnetic anomaly. Niton XRF analyses in excess of 45% iron and magnetic susceptibility exceeding 0.5 SI units are recorded in the northern end of the outcropping iron formation exposures where it is considered that folding increases the volume of magnetite.

Figure 2: Niton XRF results from rock and float samples from the iron formation  Conventional geochemical sample locations also shown.

An intense high-amplitude core magnetic anomaly shown in Figure 3 to the north west of the high iron Niton XRF concentrations does not outcrop but modeling of the magnetic data indicates that it represents an intense shallow magnetic source dipping to the south west. Elsewhere in the tenements a  number of large but discrete magnetic anomalies suggest further concentrations of magnetite not yet tested. These anomalies are shown in Figure 3 and depict the fence of oh holes drilled to test the “core” magnetic anomaly.

Figure 3: Regional Airborne Magnetic Image - highlighting area for magnetite drill testing - brown line, anomalous magnetic areas in yellow and region of sampling and mapping.

Drill Results

In July 2009 a total of 606m of Reverse Circulation drilling was carried out in three drill holes across the core anomaly (see figure 4). Table 1 shows details of the drilling.

Table 1:  Drill hole collar information    * MGA Zone 54, Based on hand held GPS

Figure 4: Drill hole location over total magnetic intensity image (GDA94 Zone 54)

Drilling encountered a thick magnetite siltstone units dipping approximately 45 degrees to the southwest in all holes (see figure 5).

Figure 5 Schematic cross section with units determined by Davis Tube Recovery (DTR) results and concentrate grades shown.

Davis Tube Recovery Results

Davis Tube Recovery tests are a test undertaken on samples from the drill hole that apply a magnetic field to the sample. Attract the magnetite and removes all the non magnetic material (waste). The results are presented as a percentage weight of total sample of the magnetic material (DTR) which is then assayed and presented as percent iron (% Fe) and other common deleterious elements.

The Davis Tube Recovery results confirm geological observations of the drill chips that thick magnetite mineralisation has been discovered at the Hawsons Iron Project. Best results from the drilling for intervals carrying no internal waste using a 20 wt% DTR cut are:

RC09BRP01:  4m @ 24.65% DTR with a DTR grade (DTRG) of 70.6% Fe from 194m.

RC09BRP02:  14m @ 21.86% DTR with DTRG of 69.7% Fe from 163m
                        13m @ 20.33% DTR with DTRG of 70.1% Fe from 183m

These highlighted intersections are contained within a wide envelope of magnetite mineralisation (Figure 5 – cross section) averaging 18.0 percent recovered  DTR concentrate. The summary table below shows the drill intersections with a recovered DTR concentrate greater than or equal to 18 percent.

The quality of the recovered concentrate (DTRG) at the standard 38 micron grind used by the laboratory is excellent, with the average for all composites analysed being:

The DTRG indicates the concentrate is composed of a pure iron magnetite with negligible silica and other deleterious elements.

Exploration Target

The magnetic Unit 3 intersected by drilling, is one of five parallel units within the Hawsons core anomaly identified in aeromagnetic data (Figure 6).  Based on the drilling and modelling of the aeromagnetic data it is interpreted by the Company that magnetic Unit 3 represents an exploration target1 of: 

100 - 115 million tonnes at 20 - 21% DTR with a DTRG  of 69 - 71% Fe to 400m
(50 – 60 million tonnes at 20 – 21% DTR with a DTRG of 69 – 71%  Fe to 250m)

415 - 480 million tonnes at 18 - 19% DTR with a DTRG of 69 - 71% Fe to 400m
(200 – 220 million tonnes at 18 – 19% DTR with a DTRG of 69 – 71%  Fe to 250m)

The exploration targets for magnetic Unit 3 are based on a tabular bedding interpretation and assumptions outlined in the table below.

¹ The term "Target" should not be misunderstood or misconstrued as an estimate of Mineral Resources and Reserves as defined by the JORC Code (2004), and therefore the terms have not been used in this context. It is uncertain if further exploration or feasibility study will result in the determination of a Mineral Resource or Mining Reserve.

Figure 6: “Tilt” Filter of Aeromagnetic Data  -  highlights magnetic units
interpreted to be magnetite units

Additional Hawsons Potential

The other four magnetic units within the core Hawsons anomaly have not been tested by drilling and it is clear there is a very large tonnage potential within these units and in other large magnetic features identified in the project area (Figure 7 and 8).

Figure 7: Zoom of  “Tilt” over “core anomaly” showing interpreted
magnetite units with drill holes shown in yellow

In Figure 7 four additional magnetic units are shown and can be interpreted as :

Unit 3   -  2.3 kms strike length
(Exp’ Target 1   :  50 – 60 mt @ 20 – 21% DTR , 69 -71% Fe ) see above
Unit 1   ~  2.0 kms  strike length
Unit 2   ~  2.5 kms  strike length
Unit 4   ~  2.0 kms strike length
Unit 5   ~ 1.75 kms strike length

Thus the Core Anomaly is considered to have a 10.5 strike kms  of potential magnetite units i.e. 4.5 times that of unit 3.

Elsewhere in the regional  magnetic image (figure 3) an additional four high potential magnetite units can be interpreted. These anomalies are considered to contain substantial volumes of magnetite and have never been drill tested.  To gain an estimate of this potential a conservative interpretation of the strike length from each anomaly is given below:

Core         10.5 strike kms length   (as shown above)
T         ~  5.5 kms  strike length
Fold      ~  7.0 kms  strike length
South L’  ~  9.0 kms strike length
Wonga     ~  ?  Large - est. 10 kms

This equates to a total in excess of  42  kms strike potential of possible magnetite bearing host rocks.

The results from the exploration work to date when combined with the airborne magnetic data suggests  a large tonnage potential, of clean magnetite concentrate. Even though the DTR grade is only moderate, the conceptual mine plan for Unit 3 indicates a simple open cut with a low waste to ore. Good infrastructure including rail, power and proximity to Broken Hill as a service centre will be of great importance to this project. 

Further exploration work is to be undertaken to better understand the grade of other magnetic targets, establish an inferred resource at Unit 3 and scope out potential  mining and processing techniques and  transport costs of a product to market.