お知らせ • Aug 11
Tertiary Minerals plc Completes Phase 4 Drill Programme At Target A1 Mushima North Project
Tertiary Minerals plc (AIM: TYM) has completed the Phase 4 drill programme at Target A1, Mushima North Project in Zambia and new preliminary results from portable X-Ray Fluorescence (pXRF) analysis of drill samples. Not all pXRF results are available yet and while they remain subject to confirmation by certified analysis, the results obtained to date appear to support the previously reported near surface Exploration Target of 15-30 million tonnes at 40-60 g/t silver equivalent and also the presence of a higher-grade mineralised zone. Mushima North is located in the prospective Iron-Oxide-Copper-Gold region of Zambia. Target A1 is a polymetallic, silver-copper-zinc prospect located 28km to the east of the historic Kalengwa copper-silver mine which is currently under redevelopment. Phase 4 drilling is now complete, with 3,639m drilled over 39 holes. Higher-grade silver-copper zone presence supported by drill intersections including (downhole widths, true widths unknown): 15m at 0.53% Cu from 100m downhole (26TMNRC-063), including 7m at 0.77% Cu from 101m downhole; 4m at 0.68% Cu from 85m downhole (26TMNRC-065); 8m at 0.62% Cu from 51m downhole (26TMNRC-073). Infill drill hole results continue to support the wider Exploration Target of near surface silver-copper-zinc oxide, with drill intersections including (downhole widths, true widths unknown): 65m at 0.23% Cu from 19m downhole (26TMNRC-069); 83m at 0.16% Cu from 19m downhole (26TMNRC-059). Currently reporting only copper and zinc pXRF results in full, as pXRF is less reliable for silver, but the high-grade zone has yielded values of up to 408 g/t silver and the larger exploration target has yielded values of up to 135 g/t silver in line with expectations. Samples submitted to the certified laboratory and results expected in the coming weeks. Initial metallurgical testwork to commence imminently, followed by the Mineral Resource modelling. The preliminary results from the Company's internal analysis using a pXRF analyser continues to not only support the current extent of the oxide mineralisation contained within the Exploration Target, and in places to potentially extend this, but also the presence of a higher-grade silver and copper zone within the core. The potential extent and tenor of silver mineralisation is not yet being reported as the pXRF results for silver are not sufficiently reliable to indicate average grades over known mineralised extents. Certified, independent laboratory analysis is currently underway to confirm silver values, along with copper and zinc and other potential, important accessory metals including bismuth, antimony and gallium. pXRF results from the remaining 9 holes drilled are expected imminently and include the last of the infill drilling of the current model at Target A1, along with testing for additional mineralisation in the west of Target A1 and at Target A2. The certified laboratory results will be announced on an on-going basis. A total of 39 holes (for 3,639m) Reverse Circulation (RC) drilling were drilled as part of the Phase 4 drill programme. Holes were planned as a series of east-west drill lines spaced approximately 100m apart (north-south). Holes were collared approximately 50m apart along the east-west lines and drilled to vertical depths of up to 128m. This was the maximum depth capability of the drill rig under the drilling conditions, in particular the higher than expected water table and resultant wet samples. Drilling was completed in two passes to allow preliminary results to support a more dynamic drill programme and the updating of our geological model as new data became available. Sampling from the drilling programme was undertaken at 1m intervals and two subsamples were collected from each interval using a riffle splitter: one for potential laboratory analysis, the other for future reference. Samples are being initially analysed on site using a pXRF analyser for copper, zinc and silver. Analysis protocol includes the averaging of two analyses per sample (unprepared sample analysed through a thin plastic sample bag) and the inclusion of Certified Reference Material, blanks and duplicate samples as part of an internal Quality Assurance (QA) procedure. Given the nature of the unprepared sample and point analysis, this method is being used as a preliminary analytical technique to provide an approximate quantitative measure of copper and zinc grades. Samples from selected drill holes based on the initial pXRF results are being sent to the independent laboratory, ALS Global, located in South Africa for analysis for a range of elements using a four-acid digest, method code ME-ICP61 (including silver, copper, zinc, bismuth, antimony and gallium). QA samples (Certified Reference Material, duplicates, blanks) will be inserted and monitored as part of the Quality Assurance Quality Control (QAQC) protocol. Reported drill hole intersection thicknesses are downhole thicknesses and true thicknesses are unknown. Intersections are weighted averages on zinc (using a cut-off grade of 0.2% Zn) or copper (using a cut-off grade of 0.1% Cu) with up to 3m internal dilution. Target A1 is a near surface, tabular body located within the oxide zone and is some 500m long, 300m wide and up to 75m thick (based on a lower cut-off of 25 g/t silver equivalent). However, the mineralisation remains open to the northwest, southwest and at depth and so the full geometry of the mineralisation remains to be determined. The potential for the near surface oxide mineralisation to transition to underlying sulphide mineralisation has yet to be tested. Elevated bismuth (up to 991 g/t), antimony (up to 824 g/t) and gallium (up to 40 g/t) are also associated with the mineralisation, but, as yet, have also not been fully investigated.