공시 • Jun 15
Riversgold Limited Announces Assay Results from the Field Campaign Recently Completed At Its Tambourah Lithium Project
Riversgold Limited announced assay results from the field campaign recently completed at its Tambourah Lithium Project in the Pilbara, Western Australia. The mapping program covered approximately 11km (4% of the Tambourah Project), focusing on 2km of the approximately 12km of the western granite/greenstone contact under tenure. No work was conducted on the additional 22km of strike of the eastern granite greenstone contact. A total of 57 rock chip samples were collected, covering a range of geological settings, prospective for economic mineralisation including 29 samples specifically for lithium mineralisation. Over the course of 2 weeks in late April2, the RGL team conducted a mapping and surface sampling campaign at the recently granted and acquired Tambourah Lithium Project located 160km south of Port Headland in the lithium rich Pilbara region of Western Australia. RGL's team covered an area of approximately 11km, representing a very small fraction (4%) of the tenement package. RGL's geologists have identified at least two generations of pegmatite dykes in the area. A first generation (G1) pegmatite dyke, composed of quartz, feldspar, muscovite, and a series of other secondary minerals, does not display obvious lithium bearing minerals. G1 dykes are thicker and more prevalent in the topography. The G1 dykes are mostly parallel to thegranite/greenstone contact of which RGL controls 12km of strike.Second generation pegmatite dykes (G2) have been identified cross cutting the G1pegmatites and contain lithium bearing minerals, in particular lepidolite which is easilyidentified by geologists in the field. On RGL's tenure, the G2 dykes develop along two mainstructural directions, N030 at Bengal and N125 at Ragdoll and Lion.A total of 49 samples of pegmatites were collected: 20 of the G1 pegmatites, and 29 of theG2 pegmatites. G1 pegmatites samples were collected with the view to analyse theircomposition in certain trace elements to find out whether the G1 and G2 pegmatites arerelated. Lion Prospect:The outstanding result is the Lion Prospect where 12 rock chips returned grades between1.49% and 3.14% Li2O, with an average of 2.24% Li2O, over a strike length of 300m in twoparallel pegmatites up to 20m apart. The Lion Prospect is located 200m directly south of theRagdoll prospect.A total of 14 samples were collected over the Lion Prospect during April 2022 by RGL.G1 pegmatites running parallel to the contact between the granitic dome and the greenstonewere interpreted as the oldest and are, in the great majority, visually constituted of a mix offeldspar and "white micas". These older pegmatites are crosscut by the younger G2 lepidoliterich pegmatites striking at 125 over 300m of combined strike length with a variableoutcropping thickness reaching 2m of massive lepidolite crystals.Two samples at Lion were collected within the G1 pegmatites and a total of 12 samples withinthe younger lepidolite rich G2 pegmatites.Assays results for those samples presented low lithium tenor within G1 pegmatites whilelepidolite rich G2 pegmatites presented Li2O values from 1.32% to 3.14%. The assay resultsalso show consistent associated caesium, rubidium and tantalum, all of which are possibleassociated credits when processed.The consistent high grade over the length of the pegmatite indicates the potential of wide andextensive high-grade mineralisation at depth. RGL's recent interpretation of high resolutiongeophysics flown at 25m spacing will be combined with a geochemistry sampling programwhich is due to commence shortly to further develop of the geological model.Ragdoll Prospect:Field work at Ragdoll has led to a reinterpretation of the mineralisation. Older feldspar, micasG1 pegmatites running parallel to the contact are crosscut by lepidolite rich pegmatitesstriking at 125 degrees. Three main lepidolite rich pegmatites were observed and have eachan outcropping strike length of about 100m.Assays results of 12 new samples within those younger G2 pegmatites ranged from 0.94%Li2O to 2.11% Li2O.Bengal Prospect: Bengal Prospect is located within the top north-west corner of the Tambourah tenement. It is constituted by a series of parallel 45 degrees striking pegmatites within the greenstones. Those pegmatites outcrop over an area of 300m x 300m. Mineralisation at Bengal is constituted of silicified lepidolite zones within wider feldspar, micas pegmatites. New rock chip samples over the Bengal Prospect area returned values up to 1.68% Li2O within a newly discovered pegmatite.Figure 3, shows the relative location of RGL's north-west prospects at Tambourah and thelocation of Minrex Resources Limited's (MRR:ASX) recent rock chip sample (MRR040)grading 1.91% Li2O, 376ppm Cs, 65 ppm Ta and 45ppm Nb at their Tambourah SouthProject, as reported on 11 April and 30 May 2022. RGL reported a rock chip (TB031) of1.91% Li2O, 260ppm Cs, 2,180 Rb, 58 ppm Ta and 45ppm Nb, south-east and along strikefrom MRR040.It is evident from Figure 3, that RGL tenements E 45/5721, ELA 45/6213 and ELA 45/6115cover the majority of the greenstone area abutting the Tambourah and Shaw domes. Todate, RGL as explored 7kms of the 11km along the western contact. The 22km long easterncontact has yet to be explored. The RGL exploration team is mobilizing there this month tocommence these activities.To date, Riversgold has only explored 7km out of 34km of prospective contact between thegranites and the greenstone where the LCT rich G1 pegmatites are easily identified in theolder gneiss. Within the 7km mapped contact, the current priority target is the combinedprospect area starting at the yet newly discovered G2 pegmatite to the north, extending southto Ragdoll and then again to Lion. This covers an 800m contact strike length and will likelybe explored as a single large mineralised geological system.While the mineralisation observed was mainly constituted of lepidolite, it is RGL's hypothesisthat, like both Pilbara Mineral's Pilgangoora and Liontown's Kathleen Valley projects, theoutcropping part of the mineralisation is represented by the weathering resistant lepidolitewith less weathering resistant spodumene likely to be present within the fresh greenstonerock at depth.