Ammaroo Phosphate Resource Update
Perth, Dec 9, 2014 AEST (ABN Newswire) - Rum Jungle Resources Limited (
ASX:RUM) is pleased to announce an updated Ammaroo Phosphate resource estimate. This upgrade is the result of the reconciliation of identified cultural exclusion zones that has recently been conducted in conjunction with the Central Land Council.
Estimated resources now total 1.145 billion tonnes P2O5 at an average grade of 14% P2O5 using a 10% cut-off or 348 Mt at 18% using a 15% cutoff.
The tonnage at 10% cut-off resource has increased by 10 million tonnes from the previous September 2014 estimate. All of this increase is within the Measured Resources and represents a tonnage increase of 8% for this category.
These updated estimates reflect reconciliation of cultural exclusion zones as determined by the Central Land Council. The underlying model has not been changed from the one used for the September estimates.
The current estimates are based on data from RC and diamond drilling completed by Rum Jungle Resources (RUM) and Central Australian Phosphate (CEN) since 2010. The study database comprises 3,372 RC and 88 diamond holes for 108,462 metres of drilling. The estimates include Measured, Indicated and Inferred resources as estimated by independent consultants MPR Geological Consultants Pty Ltd and are reported accordance with JORC 2012 guidelines. The break-down of the resource estimates is given in Table 1 in link below. The figures in this table are rounded to reflect the precision of the estimates and include rounding errors.
As shown in Figure 1 in link below, cultural exclusion zones determined by Traditional Owners and the Central Land Council have been excluded from the resource estimate. Future resource drilling activities will be restricted by these zones.
Resources were estimated by Ordinary Kriging of one-metre downhole composited assay grades from RC and diamond drilling within mineralised domain wireframes interpreted from phosphate assays and geological logging. Two models, A and B, were constructed.
Model A, which is used for reporting estimates at P2O5 cut off grades of 10% and higher is based on a mineralised envelope capturing zones of continuous mineralisation grading more than approximately 10% P2O5 with a comparatively small internal higher grade domain interpreted at nominally 23% P2O5 cut off.
Model B, which is used for reporting estimates at 5% cut off is based on mineralised domains capturing zones of continuous mineralisation grading more than approximately 5% P2O5. The Model B domains comprise a main envelope covering most of the resource area, and a subsidiary shallower zone at Limestone Bore which contributes around 2% of the model estimates. The Model B domains extend over approximately 42 km of strike with an average width of approximately 3.8 km, and an average thickness of around 10.5 m. The estimates extend to around 70 m depth, with approximately 95% from depths of less than 45 m.
All estimates include a density of 1.7 t/bcm on the basis of 183 immersion density measurements of drill core from 43 diamond holes in the west of the resource.
For cut offs of up to 15% P2O5, estimates for mineralisation with consistent drill hole spacing of up to 100 m by 100 m and 200 m by 200 m are classified as Measured and Indicated respectively and estimates for more broadly sampled areas within generally 300 m of drilling are classified as Inferred. Classification of estimates at higher cut offs reflects the reduction in continuity with increasing cut off grade as described in Appendix 1. Model estimates for broadly sampled areas more than generally 300 m from drill holes have been used for estimation of Exploration Targets.
The Limestone Bore area includes approximately 4 km of potential mineralised strike tested by a single traverse of 200 m to 400 m spaced RC holes as shown in blue in Figure 1 in link below. This area has insufficient drilling for estimation of Mineral Resources. Broadly spaced drilling in this area suggests the presence of an Exploration Target of around 50 Mt to 100 Mt at 8% to 10% P2O5 at a cut off grade of 5% P2O5, and 10 to 20 Mt at 12% to 15% P2O5 at a cut off of 10% P2O5. These estimates are based on broad spaced drilling. The potential quantities and grades are conceptual in nature. There has been insufficient exploration to estimate a Mineral Resource and it is uncertain that future exploration will result in estimation of a Mineral Resource. If further drilling were to be undertaken, 30 or more or holes at 50 metres deep would be required to infill to the standard 400 m x 400 m pattern used for estimation of Inferred resources.
The Exploration Target estimates are derived from portions of the Ordinary Kriged model with approximately 200 m to 400 m by 2 km spaced drilling trimmed to cultural exclusion zones with appropriate factoring and rounding to generate a range of tonnages and grades.
The pre-feasibility study conducted by Worley Parsons was completed prior to this resource upgrade and has been announced previously.
To view figures and tables, please visit:
http://media.abnnewswire.net/media/en/docs/ASX-RUM-416436.pdf
About Verdant Minerals Ltd
Verdant Minerals Ltd's (ASX:VRM) strategic intent is to create shareholder value through the discovery, development and operation of fertiliser and industrial mineral projects, located in close proximity to existing transport infrastructure, with a primary focus on the Northern Territory of Australia.
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