The updated resource is based on: Revision of the reporting cut-off grade using project specific factors.
Inclusion of recent infill and extension drilling data3.
Inclusion of infill drill data and additional geological information increasing resource classification confidence in a portion of the MRE
Commenting on the issue of the resource estimate,
The updated Mineral Resource Estimate further demonstrates the potential of the
Encouragingly, the resource grade is maintained at the upper end of expectations defined in the Exploration Target4. The cut-off grade changes derived from project specific inputs have been validated as consistent with peer ionic adsorption rare earth projects, further reinforcing our expectations to be a low cost REO producer.
It is particularly noteworthy that Makuutu continues to demonstrate a significantly larger mineral endowment than some peer ionic adsorption clay projects, and with a highly desirable CREO/HREO content and basket potential as recently announced to the market5.'
Cut-Off Grade Evaluation
The initial maiden Mineral Resource Estimate announced by IXR on
As a function of this increase in knowledge of these factors, the resource cut-off grade has been reduced in line with industry peer reporting to 300ppm TREO-Ce2O3. The revised cut-off grade is considered consistent with peer ionic adsorption rare earth element (REE) clay projects using similar processing technologies. The resource reported above this cut-off is considered to have reasonable prospects for eventual economic extraction in accordance with the requirements of JORC (2012) Code.
Resource Classification
Eight infill drill holes were completed in the recent COVID-19 truncated drill program. These holes were spaced 200 metres from existing (2019) 400 metre spaced drill holes within the maiden MRE area. In addition to this recent drilling, the historical RAB drilling7 geological logging has been reclassified and applied to support confidence in the regolith zone boundary definition used in the MRE model.
The resulting data has provided geological and geostatistical support for the resource grade estimation and increased the resource confidence in the drilled areas.
Resource Extension
The maiden resource has been expanded to incorporate two extension holes RRMDD055 and RRMDD056 that were drilled in
Resource Limits
The reported Mineral Resources include only clay and saprolite regolith types with surface hardcap excluded while processing alternatives are tested for this material. The reported Mineral Resources have been assessed against a resource limiting optimisation shell using appropriate marginal cost, metallurgical recovery, and price assumptions. The shell is contiguous across most of the modelled resource and limited primarily by the extent of the model.
Summary of Material Information Used to Estimate the Mineral Resource
The following is a summary of material information used to estimate the Mineral Resource, as required by Listing Rule 5.8.1 and JORC 2012 Reporting Guidelines.
Mineral Tenement and Land Tenure Status
IXR to contribute
During the earn-in phase there are milestone payments, payable in cash or IXR shares at the election of the Vendor, as follows:
At any time should IXR not continue to invest in the project and project development ceases for at least two months RRM has the right to return the capital sunk by IXR and reclaim all interest earnt by IXR.
Geology
The Makuutu deposit is interpreted to be an ionic adsorption REE clay-type deposits like those in
The weathering developed a lateritic regolith with a surface indurated hardcap, followed downward by clay rich zones that grade down through saprolite and saprock to unweathered sediments. The thickness of the regolith is between 10 and 20 metres from surface. The REE mineralisation is concentrated in the weathered profile where it has dissolved from its primary mineral form, such as monazite and xenotime, then adsorbed on to fine particles of aluminosilicate clays (e.g. kaolinite, illite, smectite). This adsorbed REE is the target for extraction and production of REO.
Drilling Techniques and Hole Spacing
Drilling completed at the
Sampling
Sample lengths were determined by geological boundaries with a maximum sample length of 1 metre applied in clay zones and up to 2 metres in laterite zones where core recovery was occasionally low. Where the core contained continuous lengths of soft clay a carving knife was used to cut the core. When the core was too hard to knife cut it was cut using an electric core saw. Using either method, core was initially cut in half then one half was further cut in half to give quarter core. Quarter core was submitted to ALS for chemical analysis using industry standard sample preparation and analytical techniques. Half core was collected for metallurgical test work. Certified reference materials (CRM), analytical blanks, and field duplicates were used as part of the QAQC procedures and were each inserted at a rate of 1:25 samples.
Sample Analysis
All DDH samples were dispatched by air freight direct to ALS laboratory
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