Exploration

Billiton explored the Mumbwa licence area during the mid to late 1990's. The following conclusions were derived from the mapping, geophysics, geochemistry and drilling completed.

The Kitumba region contains a large, and in the areas tested so far, low-grade copper or copper-gold bearing, breccia system comparable in size to the Olympic Dam Breccia Complex.

Geological, textural and geophysical data support the presence of intensive leaching and oxidation of the upper portions of the breccia systems, particularly where silicification is weak.

Geophysical and geological data support the presence of a large, potentially supergene enriched zone at the base of the oxidised zone (~250-500m). However, this target and theory has not been adequately tested.

The geological structure of the target area is not well understood and a better understanding of this may assist in focusing further exploration.

A better understanding of the geophysical properties of the rocks in the Kitumba targets is required for the effective placement of further drill holes.

A Falcon^TM survey provides the best means of providing a better understanding of the geological structures and the geophysical properties of the Mumbwa licence area.

It has been demonstrated from BHP Billiton's internal interpretation work carried out on Olympic Dam (South Australia) that it may be possible to discriminate the major mineralised systems in an IOCG province using 3D inversion of regional gravity and magnetic data.

The Falcon^TM data complements the existing geological, geophysical and geochemical data. The data was analysed for related vertical gravity gradient ("GDD") and magnetic anomalies that may indicate the presence of IOCG style mineralisation. The targets were ranked based upon the GDD signal amplitude, a real extent, related magnetic signature, as well as anomalous uranium signatures and their location with respect to mineral occurrences and favourable drill results. Interpretation culminated in a total of 23 anomalies being identified by the Falcon^TM survey, of which 11 priority drill targets were sited from for drilling.

In 2006/2007, Phase 2 of the exploration program completed drilling 8 holes totalling 4105.17m, of which drillhole S36-001 intersected 655m at 0.46% copper. This drill hole terminated in mineralisation at 697.4m, and the drill rig did not have the capacity or drill rods to progress further. The average depth of drillholes from the Phase II drilling program were in excess of 500m depth.

In 2007/2008, Phase 3 of the exploration program was initiated, proposing to core drill 8,000m from a planned 20 hole program. Drilling commenced in January 2008, utilising two drilling rigs to follow up on encouraging results identified during the previous Phase 2 drilling campaign. The proposed drill holes are listed, and provide the proposed hole depths and trend of the drillholes.

Phase 3 Mumbwa JV Drilling Program - 2008
#	Hole ID	Dip (degrees)	Azimuth (degrees)	Proposed Depth (m)	Easting (m)	Northing (m)	Results Received
1	S36_007	-70	090	700	479,353	8,374,450	Yes
2	S36_009	-70	090	700	479,153	8,374,450	Yes
3	S36_010	-70	090	800	478,952	8,374,050	Yes
4	S36_014	-70	090	700	479,151	8,373,650	Yes
5	S36_008	-70	090	700	479,352	8,374,050	Not Sampled
6	S36_002	-70	090	700	480,137	8,374,453	Yes
7	S36_011	-70	090	700	479,351	8,373,650	Yes
8	S36_016	-70	090	400	479,153	8,374,253	Yes
9	S36_020	-70	090	400	479,253	8,374,253	Yes
10	S36_021	-70	090	400	479,353	8,374,253	Yes
11	S36_017	-70	090	400	479,153	8,373,853	Yes
12	S36_015	-70	090	400	479,253	8,374,053	Yes
13	S36_018	-70	090	400	479,253	8,373,853	Yes
14	S36_012	-70	090	400	479,350	8,373,250	Yes
15	S36_004	-70	090	400	479,553	8,374,453	Yes
16	S36_003	-70	090	400	479,153	8,374,653	Yes
17	S36_005	-70	090	400	479,353	8,374,653	Yes
18	S36_006	-70	090	400	479,153	8,374,853	Yes
19	S36_013	-70	270	400	479,553	8,374,053	Yes
20	S36_019	-70	090	400	479,353	8,373,853	Yes
			TOTAL	10,200

Phase III Results
Laboratory results from completed drillholes have been progressively received by Blackthorn Resources since August 2008. Currently analytical results from 16 drillholes were received. A summary of drill intersections are as follows:

S36-007
    • 5 metres @ 0.92 g/t Au between 176 to 181 metres;
    • 33 metres @ 0.23 % Cu; 0.53 g/t Au between 188 to 221 metres;
       • including 9 metres @ 0.36 % Cu between 208 to 217 metres, 
       • including 5 metres @ 0.93 g/t Au between 195 to 200 metres,
       • including 4 metres @ 0.70 g/t Au between 213 to 217 metres.
    • 26 metres @ 0.19 % Cu ; 0.82 g/t Au between 234 to 260 metres; 
       • including 12 metres @ 1.23 g/t Au between 239 to 251 metres, 
       • including 10 metres @ 0.29 % Cu between 240 to 250 metres.
    • 21 metres @ 0.26 g/t Au between 327 to 348 metres;
    • 7 metres @ 0.67 g/t Au between 543 to 550 metres;
       • including 2 metres @ 1.13 g/t Au between 543 to 545 metres.
    • 15 metres @ 0.5 % Cu between 622 to 638 metres.

S36-009
    • 2 metres @ 1.42 % Cu between 274 to 276 metres;
    • 3 metres @ 1.00 % Cu between 720 to 723 metres;
    • 2 metres @ 1.19 % Cu between 747 to 749 metres.

S36-010
    • 10 metres @ 1.37% Cu between 364 to 374 metres;
       • including 2 metres @ 3.75 % Cu between 368 to 370 metres.
    • 22 metres @ 0.39% Cu; 0.06g/t Au between 388 to 410 metres;
       • including 14 metres @ 0.46% Cu between 396 to 410 metres,
       • including 2 metres @ 0.31 g/t Au between 396 to 398 metres.
    • 40 metres @ 0.61% Cu; 0.04g/t Au between 422 to 462 metres;
       • including 14 metres @ 0.83% Cu between 422 to 436 metres, 
       • including 4 metres @ 1.63% Cu between 426 to 430 metres,
       • including 18 metres @ 0.65% Cu between 440 to 458 metres,
       • including 2 metres @ 1.02% Cu between 444 to 446 metres.
    • 18 metres @ 0.25% Cu between 486 to 504 metres;
       • including 2 metres @ 0.41 % Cu between 501 to 503 metres.
    • 4 metres @ 0.59% Cu between 622 to 626 metres;
    • 12 metres @ 0.55% Cu; 0.12 g/t Au between 642 to 654 metres;
       • including 2 metres @ 1.23% Cu between 652 to 654 metres,
       • including 2 metres @ 0.29 g/t Au between 652 to 654 metres.
    • 2 metres @ 0.50% Cu between 827 to 829 metres;
       • including 1 metre @ 0.83% Cu between 828 to 829 metres.

To view the Table of Results for S36-010, please click here

S36-014 
    • 2 metres @ 0.38% Cu between 85 to 87 metres;    
    • 1 metres @ 0.65% Cu between 118 to 119 metres;  
    • 6 metres @ 0.95% Cu between 154 to 160 metres;
       • including 3 metres @ 1.57% Cu between 157 to 160 metres;
    • 33 metres @ 0.43% Cu between 224 to 257 metres;
       • including 2 metres @ 0.49 % Cu between 224 to 226 metres,
       • and 2 metres @ 047% Cu between 231 to 233 metres,
       • and 15 metres @ 0.65% Cu between 242 to 257 metres,
         • including 1 metre @ 1.21% Cu between 243 to 244 metres,
         • and 1 metre @ 1.02 % Cu between 252 to 253 metres.
    • 9 metres @ 0.60% Cu between 263 to 272 metres;
       • including 5 metres @ 0.85% Cu between 267 to 272 metres,
         • and 1 metre @2.69% Cu between 270 to 271 metres.
    • 3 metres @ 0.35% Cu between 278 to 281 metres;
    • 7 metres @ 0.38% Cu between 309 to 316 metres;
       • including 2 metres @ 0.67% Cu between 310 to 312 metres.
    • 39 metres @ 0.51% Cu between 329 to 368 metres;
       • including 1 metre @ 1.04% Cu between 329 to 330 metres,
       • and 1 metre @ 1.31% Cu between 339 to 340 metres,
       • and 2 metres @ 1.04% Cu between 346 to 348 metres,
       • and 1 metre @ 1.02% Cu between 350 to 351 metres,
       • and 1 metre @ 1.06% Cu between 353 to 354 metres,
       • and 2 metres @ 0.74% Cu between 358 to 360 metres,
       • and 2 metres @ 0.76% Cu between 366 to 368 metres.
    • 18 metres @ 0.44% Cu between 372 to 390 metres;
       • including 4 metres @ 0.97% Cu between 380 metres to 384 metres,
       • and 1 metre @ 1.01% Cu between 389 to 390 metres.
    • 3 metres @ 0.26% Cu between 402 to 405 metres;
    • 2 metres @ 0.61% Cu between 423 to 425 metres;
    • 4 metres @ 0.29% Cu between 431 to 435 metres;
    • 3 metres @ 0.28% Cu between 462 to 465 metres;
    • 2 metres @ 0.38% Cu between 468 to 470 metres;
    • 3 metres @ 0.32% Cu between 528 to 531 metres;

To view the Table of Results for S36-014, please click here

S36-016  
    • 4 metres @ 0.36 % Cu between 88 and 92 metres;    
    • 2 metres @ 0.28 % Cu between 102 and 104 metres;    
    • 164 metres @ 0.60 % Cu between 114 and 278 metres;    
       • including 16 metres @ 0.28 % Cu between 114 and 130 metres,
       • and 2 metres @ 0.32 % Cu between 134 and 136 metres,
       • and 25 metres @ 0.40 % Cu between 139 and 164 metres,
       • and 24 metres @ 0.66 % Cu between 166 and 190 metres,
       • and 86 metres @ 0.75 % Cu between 192 and 278 metres,
          • including 6 metres @ 3.23 % Cu between 242 and 248 metres.
    • 56 metres @ 0.54 % Cu between 290 and 346 metres;    
       • including 18 metres @ 0.83 % Cu between 290 and 308 metres,
          • including 2 metres @ 3.99 % Cu between 305 and 307 metres,
       • and 12 metres @ 0.53 % Cu between 310 and 322 metres,
       • and 8 metres @ 0.59 % Cu between 325 and 333 metres,
       • and 9 metres @ 0.30 % Cu between 337 and 346 metres.
    • 8 metres @ 0.30 % Cu between 367 and 375 metres;    
    • 2 metres @ 0.33 % Cu between 387 and 389 metres;    
    • 5 metres @ 0.75 % Cu between 394 and 399 metres;    
    • 1 metre @ 0.45 % Cu between 402 and 403 metres;    
    • 1 metre @ 4.13 % Cu between 423 and 424 metres.

To view the Table of Results for S36-016, please click here

S36-015  
    • 3 metres @ 0.30 % Cu between 129 and 132 metres;    
    • 10 metres @ 0.51 % Cu between 143 and 153 metres;    
       • including 3 metres @ 0.94 % Cu between 143 and 146 metres.
    • 47 metres @ 0.47 % Cu; 0.03 g/t Au between 184 and 231 metres;    
       • including 6 metres @ 0.44 % Cu between 184 and 190 metres,
       • and 7 metres @ 0.45 % Cu between 192 and 199 metres,
       • and 2 metres @ 0.44 g/t Au between 199 and 201 metres,
       • and 4 metres @ 0.52 % Cu between 201 and 205 metres,
       • and 17 metres @ 0.58 % Cu between 208 and 225 metres,
       • and 3 metres @ 0.85 % Cu between 228 and 231 metres.
    • • 9 metres @ 0.58 % Cu between 262 and 271 metres;    
       • including 2 metres @ 0.93 % Cu between 264 and 266 metres,
       • and 2 metres @ 1.00 % Cu between 268 and 270 metres.

S36-017  
    • 4 metres @ 0.31 % Cu between 62 and 66 metres;    
    • 2 metres @ 0.35 % Cu between 74 and 76 metres;   
    • 2 metres @ 0.29 % Cu between 82 and 84 metres;    
    • 12 metres @ 0.38 % Cu between 110 and 122 metres;   
       • including 3 metres @ 1.36 % Cu between 161 and 164 metres,
       • and 3 metres @ 2.26 % Cu between 166 and 169 metres,
       • and1 metre @ 1.16 % Cu between 172 and 173 metres.
    • 20 metres @ 1.01 % Cu between 177 and 197 metres;    
       • including 12 metres @ 1.37 % Cu between 177 and 189 metres,,
       • and 1 metre @ 1.60 % Cu between 194 and 195 metres.
       • and 2 metres @ 0.44 g/t Au between 199 and 201 metres,
    • 228 metres @ 1.47 % Cu between 203 and 431 metres;    
       • including 78 metres @ 0.78 % Cu between 203 and 281 metres;
       • and 50 metres @ 4.29 % Cu between 285 and 335 metres,
       • and 87 metres @ 0.67 % Cu between 344 and 431 metres.
    •  1 metre @ 0.32 % Cu between 448 and 449 metres.
    •  4 metres @ 0.50 % Cu between 452 and 456 metres.
    •  1 metre @ 0.32 % Cu between 462 and 463 metres.

In August 2008, Blackthorn Resources and BHP Billiton negotiated a revised joint venture agreement which have a number of operational and commercial benefits to both JV partners. The original agreement involved Blackthorn Resources fully funding the first 3 phases of exploration work from a 5 phase program, in order to earn a 70% interest in the Project.

The revised agreement has reduced the total drilling required by Blackthorn Resources to 8,000m, and introduced two additional phases of exploration, allowing for a more thorough assessment of the lease area. It was agreed by the JV partners that additional drilling is warranted to adequately define the scale and scope of the Project to commence studies of the feasibility of developing the area into a mining operation.  

Under the new terms, BHP Billiton retained an option to fully fund the final 2 phases (Pre-Feasibility and Feasibility Studies). In doing so BHP Billiton would have earned back an additional 20% and 30% respectively, leading ultimately to a JV where BHP Billiton holds 80% and Blackthorn Resources 20%. Each party would then share in future project costs and benefits on a pro-rata equity basis.