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Adelaide, Mar 15, 2007 AEST (ABN Newswire) - The Directors of Alliance Resources Limited ("Alliance") (ASX: AGS) are pleased to announce an exploration update provided by joint venture partner and operator Quasar Resources Pty Ltd ("Quasar") at the Arkaroola Project in South Australia.
Four Mile West
Drilling
Eighteen (18) holes were completed at Four Mile West during February 2007 for a total of 3,107m. The program was designed to reconcile the calibration of the various gamma ray and the prompt fission neutron (PFN) tools used in previous drilling.
The resulting data are currently being assessed for finalisation of the resource estimate.
Soil Survey
A soil survey across Four Mile has commenced. Approximately 400 samples will be collected along four traverses and submitted for multi-element analysis at the completion of the program.
Monitor Wells/Water Bores
Three (3) of the four (4) monitor wells completed at Four Mile West have been set up with pumps and data loggers.
The monitor wells have been set up to test the hydrology and specifically to test the water quality, water depth and flow rates. Water samples have also been sent off to be analysed for chemistry at ANSTO.
Four Mile East
A drilling program of approximately 200 holes has commenced with two rigs at Four Mile East. The program will provide detailed data across mineralisation and interpreted structures on a 200m X 100m grid. This will encompass an area of approximately 3.75 km 2 , including small areas of 100m X 100m drilling to better delineate previously defined higher grade zone of mineralisation.
BACKGROUND ON FOUR MILE DISCOVERY AND CALIBRATION
At Four Mile West sandstone-type mineralization is clearly associated with redox (oxidation-reduction) interfaces and displays a typical roll-front morphology. Potentially economic mineralization extends over an area of 0.8 x 1.25 km oriented northeast to southwest. In the 'tails' of the deposit in the northwest, mineralization between 0.5 to 3 metres thick occurs in two superposed levels vertically separated by about 10 metres of unmineralized sediments. These gradually thicken from northwest to southeast apparently combining into a single terminal zone (the 'nose').
Natural gamma ray logging of equivalent uranium grade is available for all drill holes in the western zone at Four Mile. PFN logging has been carried out in 70% of the holes, directly and independently confirming the uranium intersections over almost precisely the same intervals. Both types of tool were calibrated at the PIRSA Adelaide Model (AMDEL) calibration facility. One cored drill hole with XRF and DNA assays provides a cross check on the calibrations.
Two different down-hole methods and several different down-hole tools have been used to measure uranium grade and equivalent uranium grade at Four Mile West. Gamma equivalent grades are available from all drill holes and a second independent gamma measurement is available from the PFN tools where PFN has been run. The two sets of gamma readings show excellent agreement. The PFN measure of uranium grade is generally the first choice method for grade estimation purposes because it responds directly to uranium and is therefore not affected by disequilibrium.
As has been reported previously there is a significant mismatch between the gamma ray measure of equivalent uranium grade and the PFN measure of uranium grade at Four Mile. Historically, gamma has always 'underestimated' grade for the sediment hosted uranium deposits of the Frome/Curnamona region, commonly explained either as gross one-way disequilibrium, and/or as combinations of disequilibrium and density and formation moisture correction factors which together have historically enabled an approximate 30% overall upgrade of the gamma equivalent grades.
At Four Mile these factors are not sufficient to reconcile the differences between gamma and PFN grades. Two different PFN tools have been used in different holes to measure uranium grade and whereas one PFN tool provides a good match for the core analyses the second tool returned significantly higher grades indicating a tool calibration problem and allowing the possibility for significant grade overestimation for the holes logged with this tool. Although this is likely to be partially compensated by conservatism in the gamma equivalent grade data the issue of grade accuracy is a limiting factor to classification of the resource to inferred status at this stage. The ongoing data validation studies at Four Mile are aimed at resolving the calibration issues and reconciling the different grade measures to allow a resource estimate to be made.
