Queensland Review - June 2010
DYL’s Mount Isa District tenement holdings cover ground that is held 100% and tenements subject to the Isa West JV with Xstrata and the Leichhardt JV with Universal Resources.
Figure 1: Mount Isa District Tenements
Key Points
The 2009-2010 period saw a number of significant developments in the Mount Isa District, namely:
- Maiden JORC Code Indicated and Inferred Mineral Resource estimate for the district totalling 3.64 million tonnes at 420 ppm U3O8 for 1,540 tonnes (3.4 Mlbs) of U3O8.
- Potential to increase resources at depth and under cover within the existing tenement package.
- Successful tenderer for the acquisition of Ewen (EPM 14916) and Yamamilla (EPM 14281) tenements from the Receivers and Managers of Matrix Metals Ltd.
-
Signing of a Letter Agreement with Universal Resources Ltd to joint venture EPM 14367, 20 km northeast of Mount Isa.
JORC CODE RESOURCES – JANUARY 2010
The 2008 drill programmes in the Mount Isa district were primarily first-pass-shallow RC holes undercutting selected surface radiometric anomalies with ± 200 metre strike to 50 to 75 metre depth. In some cases infill and undercut holes of the better intercepts were drilled.
The 2009 drill programmes saw a switch to systematic grid drilling on 25 metre spaced sections on 25 metre centres on a number of prospects with a view to delineating JORC Code resources. This was followed by a drill out on 50 metre spaced sections at 50 metre centres to 200 metre vertical depth. A summary of the 2008-2009 drill programmes is given in Table 1.
Table 1: Mount Isa District 2008-2009 Drilling Summary (October 2009)
|
Project |
No. of Holes |
Total Metres Drilled | Project |
No. of Holes |
Total Metres Drilled |
| RC Drilling | Diamond Drilling | ||||
| Ewen EPM 14916 - 2008 | 87 | 9,107 | Queens Gift Project - 2008 | 6 | 969 |
| Queens Gift EPM 15070 - 2008 | 3 | 270 | Isa West Project - 2009 | 7 | 700 |
| Isa West Project - 2008 | 81 | 6,297 | Queens Gift Project - 2009 | 4 | 620 |
| Isa West Project - 2009 | 105 | 11,621 | |||
| Queens Gift Project - 2009 | 29 | 6,467 | |||
| Total | 305 | 33,762 | Total | 17 | 2,289 |
As announced to the ASX (14 January 2010) Coffey Mining Pty Ltd (Coffey) provided DYL with an Indicated and Inferred Mineral Resource estimate for a number of prospects in the Mount Isa District, Queensland.
Using a 300 ppm U3O8 cut-off the Indicated and Inferred Mineral Resource estimate for the Isa West - Thanksgiving, Bambino and Eldorado North Prospects and the Queens Gift and Slance Prospects totals 3.64 million tonne at 420 ppm U3O8 for 1,540 tonne (3.4 Mlbs) of U3O8 (Table 2).
Using a 200 ppm U3O8 cut-off increases the JORC Code resource to 2,430 tonne at 340 ppm U3O8 indicating a significant potential upside available with decreased operating costs, beneficiation and/or increased uranium prices.
Table 2: All Prospects Combined – January 2010 JORC Code Resource Estimate
| Category | Cut-off Grade | Tonnes |
Grade (ppm U3O8) |
Metal (Tonnes U3O8) |
Metal (Mlb U3O8) |
| Inferred | > 300 | 2,020,000 | 440 | 890 | 2.0 |
| Indicated | > 300 | 1,620,000 | 400 | 660 | 1.4 |
| Combined | > 300 | 3,640,000 | 420 | 1,540 | 3.4 |
Note: Figures have been rounded
DYL’s short to medium term strategic objective to outline mineralisation amenable to open pit mining and aggregating 5,000 to 8,000 tonne (11 Mlb to 18 Mlb) of U3O8 as satellites to a future central plant in the Mount Isa area. The medium to long term target is to define 12,000 to 15,000 tonne U3O8 based on feeding a central processing plant from combined open pit and underground operations.
The individual resource estimates for each prospect are in line with that expected from surface mapping and 2008 wide spaced drilling and auger well for the continuation JORC Code resource drilling programmes as part of the short to medium-term strategic plan (2010-2012) to outline 5,000 to 8,000 tonnes of U3O8 in the Mount Isa District at ~ 400 ppm U3O8 grade.
JOINT VENTURES
Within the Mount Isa district DYL carries out exploration on its 100% owned tenements and on two joint venture areas.
In agreement with Mt Isa Mines Ltd, part of the Xstrata Group, DYL can ultimately acquire 100% of the uranium rights over a project area immediately west of the Mt Isa minesite (ASX 21 January 2008). Exploration programmes commenced in March 2008 with first maiden JORC Resources announced in January 2010.
In agreement with Universal Resources Limited, DYL may earn up to 80% interest specifically in uranium and related minerals in the tenement. DYL’s earned interest will not apply to base and precious metals or uranium as a bi-product from a deposit mined principally for its base and/or precious metal resources. (ASX 9 February 2009).
ISA WEST PROJECT (earning 100% of uranium rights from Xstrata)
Isa West JORC Code Drill Programme
Four of fifteen prospects were selected for resource drill-out in 2009, namely Thanksgiving, Bambino, Eldorado North and Turpentine prospects (Figure 2).
Figure 2: Isa West and Leichhardt JV Prospects
The Bambino and Thanksgiving prospects were drilled to approximately 200 metre vertical depth and remain open to depth but closed-off along strike.
Drilling of the Eldorado North prospect was restricted to a first lift of holes with some selective undercuts. The prospect is open to depth below 60 metre and to the south and will be drilled out at the start of the 2010 field season.
Initial RC drilling at the Turpentine prospect indicated a complex structural setting and a decision was made to postpone the RC drilling until two or three short diamond holes could be completed in order to provide ‘structural data/geological interpretation’ ahead of further RC drilling.
The JORC Code resource estimate for Isa West totals 2.33 million tonne at 410 ppm U3O8 for 960,000 tonne U3O8 (Table 3).
Table 3: Isa West Project – January 2010 JORC Code Resource Estimate
| Category |
Cut-off Grade |
Tonnes |
Grade (ppm U3O8) |
Metal (Tonnes U3O8) |
Metal (Mlb U3O8) |
| Thanksgiving Prospect | |||||
| Inferred | > 300 | 660,000 | 470 | 310 | 0.7 |
| Indicated | > 300 | 470,000 | 400 | 190 | 0.4 |
| Combined | > 300 | 1,130,000 | 440 | 490 | 1.1 |
| Bambino Prospect | |||||
| Inferred | > 300 | 670,000 | 370 | 240 | 0.5 |
| Indicated | > 300 | 370,000 | 390 | 140 | 0.3 |
| Combined | > 300 | 1,040,000 | 370 | 390 | 0.9 |
| Eldorado North Prospect | |||||
| Inferred | > 300 | 160,000 | 500 | 80 | 0.2 |
| Combined | > 300 | 160,000 | 500 | 80 | 0.2 |
| Total Isa West | |||||
| Inferred |
> 300 |
1,490,000 | 420 | 630 | 1.4 |
| Indicated | > 300 | 840,000 | 390 | 330 | 0.7 |
| Combined | > 300 | 2,330,000 | 410 | 960 | 2.1 |
Note: Figures have been rounded
ISA NORTH PROJECT
EPM 14916 EWEN - Slance Prospects
A total of 13 RC drillholes for 2,274 metre were drilled at Slance NW in December 2009.
Throughout the RC programme encouraging mineralisation was intercepted mainly to the south of the surface radiometric anomaly i.e. 28 metre at 1,159 ppm U3O8 in hole SLRC 039. The diamond hole at Slance NW further verified this with an intersection of 11 metre at 1,190 ppm eU3O8. The diamond hole at Slance NE also returned strong mineralisation identified in the 2008 drilling programme with an intercept of 23 metre at 1,012 ppm eU3O8.
The current JORC Code mineral resource stands at 460,000 tonnes at 540 ppm U3O8 for 250 tonnes U3O8 (Table 4).
EPM 15070 PROSPECTOR Queen’s Gift Prospect
Four diamond holes were drilled at Queen’s Gift in 2009, totalling 619 metre. These drillholes were located across the prospect and included two diamond tails on original 2007 RC drillholes.
The JORC Code resource estimate for the Queens Gift prospect is based on 2007 and 2009 RC drill data and on 2008 and 2009 diamond drill data and totals 850,000 tonnes at 390 ppm U3O8 for 330 tonnes U3O8 (Table 4).
The style of mineralisation and alteration is the same as that described for the 30,000 tonne U3O8 Valhalla Deposit 30 kilometre to the south.
The Queens Gift Prospect remains the single largest alteration system DYL has drilled to date in the Mount Isa District within which four mineralised lenses have been identified. The intensity and width of the alteration zone and mineralisation give good upside potential to developing resources below 200 metre vertical depth and along strike to both the north and south.
Table 4: Isa North Prospects – January 2010 JORC Code Resource Estimate
| Category |
Cut-Off Grade |
Tonnes |
Grade (ppm U3O8) |
Metal Tonnes (U3O8) |
Metal (Mlb U3O8) |
| Queens Gift | |||||
| Inferred | > 300 | 310,000 | 410 | 130 | 0.3 |
| Indicated | > 300 | 540,000 | 380 | 210 | 0.5 |
| Combined | > 300 | 850,000 | 390 | 330 | 0.7 |
| Slance | |||||
| Inferred | > 300 | 220,000 | 580 | 130 | 0.3 |
| Indicated | > 300 | 240,000 | 490 | 120 | 0.3 |
| Combined | > 300 | 460,000 | 540 | 250 | 0.5 |
| Total Isa North | |||||
| Inferred | > 300 | 530,000 | 480 | 260 | 0.6 |
| Indicated | > 300 | 780,000 | 420 | 330 | 0.7 |
| Combined | > 300 | 1,310,000 | 440 | 580 | 1.3 |
LEICHHARDT JV – EPM 14367 (DYL 51%, earning 80%)
A first pass RC drilling programme of 12 holes for 822 metre was completed at the A25 and Big Dip prospects in early December 2009. The programme achieved the objective of testing a series of north-south trending radiometric anomalies previously identified in historic reports and confirmed by fieldwork carried out by DYL earlier in the year.
A25 Prospect
Seven holes for 474 metre were drilled at A25 prospect. The most intense mineralisation occurred in the northern most hole, A25RC003 in a strongly hematite-albitite-silica-carbonate altered basalt. While stronger mineralisation seems to occur in discontinuous pods throughout the prospect, all of the drill holes intersected the same altered lithology which was up to 35 metre wide.
Big Dip
Five holes for 348 metre were drilled at Big Dip. The most intense mineralisation occurred in the northern most hole, BDRC002 – 6 metre at 918 ppm U3O8 from 42 metre in a strongly hematite-albitite-silica-carbonate altered basalt. The alteration zone is more intense but narrower and less continuous than at the A25 prospect.
The total length of the surface radiometric anomaly is 500 metre. To the north the mineralisation appears to pinch out while in the south it is truncated by a NE trending fault.
2010 EXPLORATION PROGRAMME
With the 2009 JORC Code drill programme successfully outlining indicated and inferred mineral resources of +400 ppm U3O8 to ± 200 metre vertical depth at several prospects, a decision was made to test a number of prospects to 400 metre vertical depth in order to provide information on the continuity, width and importantly grade of mineralisation at depth.
This programme will see several + 500 metre core holes being drilled initially at Isa West and Queens Gift.
The strategic plan for the Mount Isa district also involves fast-tracking surface prospects (reconnaissance RC drilling) to see if they have tonnage-grade potential that could add to the overall Mount Isa JORC Code resource inventory in 2011.