Introduction
GCR’s 100% owned subsidiary, King Eagle Resources (KER), has a large tenement package covering 876 km2 of prospective Cambrian phosphate units within the Georgina Basin. The tenements contain five major deposits of phosphorite with historically calculated resources of over 500Mt of 15.5% P205. Potential exists for the tenements to contain large low-grade uranium deposits that are formed at shallow depths where meteoric water precipitates uranium in phosphate rich horizons, permeable structures and unconformities.
Late in 2007 a joint venture agreement was signed with Legend International Holdings Inc (Legend). Under the agreements, Legend may earn an 80% interest in phosphate minerals on the tenement package by spending $3 million on exploration and development by 7 December 2012. GCR retains all rights to all other minerals, including uranium. Legend must spend $200,000 on the properties before it may withdraw from the farm-in. Once Legend earns an 80% interest in the phosphate minerals, GCR will retain a 20% interest in the phosphate minerals, free carried to a decision to mine. Legend will routinely assay for uranium as part of its exploration programs on the properties.
Geological Setting and Uranium Deposition Model
The Mount Isa district probably represents one of the most prospective areas in Australia for the discovery of near surface uranium resources and intense uranium exploration is currently being conducted by a numerous companies, including Summit Resources and Deep Yellow.
Newland Resources and Summit are currently conducting a uranium exploration program over 12,000 km2 of the Georgina Basin to the west of the Mount Isa Inlier with tenements surrounding GCR’s. Summit have variously reported JORC compliant resources of 85.3Mlb U3O8 at their Valhalla, Andersons, Bikini, Watta and Skal projects. GCR’s exploration is targeting secondary uranium deposits in reducing environments and associated structural traps within the Georgina Basin.
The Cambrian Georgina Basin in northwest Queensland contains Australia’s largest phosphate resources. These sedimentary phosphorite deposits occur where phosphorous has been precipitated as apatite group minerals in a marine environment. The main phosphate horizon, the Beetle Creek Formation, comprises a series of phosphatic siltstones and cherts overlying limestone and basal sandstone and conglomerate.
The Rimmer Hill uranium-phosphate occurrence, which is located 100km east of Quita Creek and 20km north of Southern Cross Fertilizer Pty Ltd’s current phosphate mining operation, confirms the prospectivity of the phosphorite units to host significant uranium mineralisation. Uranium at Rimmer Hill, which occurs within bedded phosphate sediments, is probably formed by the natural reduction of uranium-bearing fluids by in situ phosphate mineralisation.
Prospect Details
Quita Creek
Legend International continue to work on the phosphate potential in the Quite Creek tenement which contains two large phosphate deposits, Steamboat and Quita Creek.
The tenement is generally covered by these phosphate rich sediments but the basement to these are ultramafics of the Mt Isa western succession which is prospective for Mt Isa style copper mineralisation. The magnetic map of the tenement clearly shows the underlying ultramafics which have been modelled to be around 50m beneath the sediments. A submission has been made to the QLD Government for funding assistance under the Collaborative Drilling Initiative to drill beneath these phosphate-rich sediments to the rocks of the Western Succession. The Initiative is open to all explorers in Queensland and will pay up to $150,000 for direct drilling costs. The program planned for Quita Creek is for four holes totaling 1,000 metres of RC and Diamond drilling for which we could recover $50,000. The drilling program is expected to commence in the second quarter of this year.
Legend recently flew detailed magnetics and radiometrics over the three tenements. KER had the radiometrics remodelled and the results highlight several areas of anomalous uranium as can be seen by the figure opposite. In general colours yellow to red a three to five times the average background value. Some of these anomalous zones are several hunderd metres long. When viewed in conjunction with the topography these zones tend to be located at the same RL which indicates that they are stratigraphically controlled. This bodes well for locating useful uranium mineralisation and these areas will be the first to be worked on once the wet season subsides.
Lily & Sherrin Creeks
The tenement is located approximately 100km northwest of Mount Isa and a covers Cambrian sedimentary basin to the west of the Sybella Granite complex – a potential uranium source.
The property lies 50 km west of the Valhalla and Skal uranium deposits and contains two large phosphorite deposits. The primary target is secondary enrichment occurrences of uranium within the phosphate deposits.
Like in the Quita Creek tenement the new radiometric data has
highlighted several areas with anomalous uranium responses. And like Quita Creek the distribution of these anomalies with respect to topography indicates that they are stratigraphically controlled. While there are fewer anomalies that Quita Creek those that exist are certainly worth following up once we have gained access to the area after the monsoon season.
Highlands Plains
The property is located about 200km northwest of Mount Isa and 90km south of the Westmoreland uranium deposit which contains 21,000 tonnes of U3O8. The tenement also contains phosphorite mineralisation within the Cambrian sedimentary basin. The primary target for GCR is secondary enrichment occurrences of uranium within sedimentary phosphate deposits.
The Legend survey was restricted to the north-western corner of the tenement so the data was not as useful here. However lower resolution data is available from previous explorers and the diagram to the left is a composite image of three radiometric channels with potassium coloured red, throium coloured green and uranium coloured blue. The white areas are where all three components are high and black areas where none of them are high. The preponderence of green and blue in the tenement suggest that thorium and uranium and the dominant components and the areas of blue the most prospective if searching for uranium.
Negotiations with the traditional landowners have been successful and Legend have permission to drill the first phase of 60 RC holes in the phosphate deposit. This work is expected to commence after the monsoon season sometime after March.