Osino Significantly Increases Size of Total Gold Resource Adds 0.9 Moz Inferred Mineral Resource From Ondundu Gold Project, Namibia
- Total Ondundu gold project maiden resource estimate of 26 million tonnes (Mt) at anaverage grade of 1.13 g/t Au for a total of 0.9 million ounces (Moz) of gold in the Inferred mineral resource category (0.5 g/t cut-off).
- Osino’s total Namibian gold resource inventory now stands at 2.77 Moz (Measured and Indicated) and 1.14 Moz (Inferred).
- Ondundu is Namibia’s oldest known gold deposit with a history of mining and exploration by various operators dating back to German colonial times from 1917.
- The deposit is known for its coarse and nuggety gold mineralization, which gives rise to narrow high grade gold intersections which are complex to model but represent potential upside which Osino aims to demonstrate with larger sample size and infill drilling which will commence shortly.
- Recently completed metallurgical test work confirms excellent amenability to gravity concentration with the potential to produce a low volume, high-grade gravity concentrate with the potential for onward road transportation and processing at Osino’s PFS-stage Twin Hills gold development project, 130 km’s by road to the south east.
VANCOUVER, British Columbia, Oct. 27, 2022 (GLOBE NEWSWIRE) — Osino Resources Corp. (TSXV:OSI) (FSE:RSR1) (OTCQX:OSIIF) (“Osino” or “theCompany”) is pleased to announce a maiden mineral resource estimate (“MRE”) for Osino’s Ondundu Gold Project comprising 26 million tonnes (Mt) at an average grade of 1.13 g/t Au for a total of 0.9 million ounces (Moz) of gold in the Inferred mineral resource category (0.5 g/t cut-off).
Ondundu is 100% owned by Osino and is located approximately 130 km northwest of Osino’s flagship Twin Hills Project in Namibia. Osino completed the acquisition of Ondundu from B2Gold Corp. (“B2Gold”) on July 21, 2022.
Heye Daun, Osino’s President & CEO commented:“We are very pleased with the completion of this maiden resource estimate at Ondundu, which adds almost a million ounces of gold at 1.13g/t and significantly increases the size potential of our combined Namibian gold portfolio. Ondundu is the oldest known gold deposit in Namibia, with a history of small-scale gold production and historical technical work by a range of operators, including most recently B2Gold. These operators recognized Ondundu’s significant potential due to its extremely coarse and nuggety nature of gold mineralization. Given the nature of the deposit, we believe that there is potential to improve the grade and size of the deposit with additional drilling and using larger sample volumes. This will be tested with a limited RC drill program which is about to commence. Our vision of delivering a feasible mining and process route involving gravity pre-concentration at Ondundu with subsequent processing at Twin Hills is now one step closer to fruition.”
The mineral resource was estimated from approximately 46,500m of diamond core (“DD”) and reverse circulation (“RC”) drilling, which was completed by previous operators, but mainly B2Gold between 2015 and 2020 but was never converted into a code-compliant MRE. Drill collars were spaced on various grids from 25m to 100m on surface and inclined at 60° at an azimuth of 70°.
Gold mineralization occurs along a continuous 2.1km strike length and within a 200m wide corridor, although this width is not necessarily mineralized throughout. Gold mineralization is modeled to a depth of approximately 320m below surface. The mineral resource has reasonable prospects for eventual economic extraction based on conceptual mining costs and parameters, and a gold price of US$1800/oz.
Ondundu Project Location
The Ondundu Gold Project is located in north-central Namibia approximately 270km northwest of Windhoek and 130km northwest of the Company’s Twin Hills Gold Project (Figure 1). It lies within EPL 3195 which has an area of 10,386.5 hectares.
Figure 1: Ondundu Gold Project location relative to Osino’s Namibian ground holdings
The Ondundu Project area has a long history of mining and exploration since its discovery in 1917. Between 1922 and 1964 approximately 20,000 ounces of gold were recovered by small scale miners.
Systematic exploration commenced in the 1980’s and the first documented drilling was carried out by Tsumeb Corporation Ltd (TCL) (1980-1985), with similar programs by Goldfields Ltd (1985-1990) and Westport Resources Namibia (Pty) Ltd (2005-2010). The first major drilling campaign was conducted by Angus Mining Ltd in 2010 and 2011. B2Gold’s involvement in the project commenced in 2015 and they were responsible for the majority of drilling at the Project until 2021.
The drilling database was consolidated by CSA Global from an Access database which was supplied to Osino by B2Gold. The data was validated and some collars verified in the field by the responsible qualified person (QP).
The validated database totals 74,832m of drilling from 854 holes and 5,166m of trenching (Table 1 and Figure 3). DD holes range from 22m to 650m in depth, while RC holes range from 20m to 202m in depth. Most of the drillholes were oriented at 70° azimuth and 60° dip.
Drillholes were generally sampled at one-meter intervals. A subset of this data, approximately 46,500m of mostly DD, was used for the mineral resource estimate.
Table 1: Drilling and trenching database
|1985-1990||Goldfields / TCL||6*||1,729|
Note: * including deepening of 2 existing TCL DD holes. DD is diamond core drilling, RAB is rotary air blast drilling, RC is reverse circulation drilling, RCDD is reverse circulation pre-collar drilling with diamond core tails, and TRCH is trenching
Geological logging and sampling methodology were reviewed for drill core (B2Gold campaign) at the Ondundu core yard by the QP in accordance with National Instrument 43-101 (“NI 43-101”) requirements and was deemed to be reasonable and acceptable.
The Project is located in the Northern Zone of the Damara Orogen in Namibia, about 15 km north of the Autseib/Otjohorongo Fault. The Project area is underlain entirely by meta-sedimentary rocks of the Kuiseb Formation of the upper Swakop Group, comprising schistose quartz feldspar mica meta-greywacke and meta-pelite rocks, which are often calcareous. The rocks in the Project area are metamorphosed to greenschist facies.
The main geological feature in the Project area is the low amplitude Ondundu anticline, a major north-trending antiformal fold which plunges approximately 30° to the south. Parasitic folds within the regional anticline have concentrated gold mineralization mainly in bedding parallel veins. The Ondundu anticline and its parasitic folds have an axial planar slaty cleavage which trends north to north-northeast and dips steeply west.
The main mineralization from Margarethental in the north to Razorback in the south (the Ondundu Main Zone or OMZ), occurs on the steep west facing limb of a parasitic syncline-anticline pair (previously termed the “Common Limb”) on the eastern limb of the southeastern part of the Ondundu anticline (Figure 2). The other limbs of the syncline-anticline pair are shallow dipping.
The Common Limb is anomalous in the Project area in its steep dip, although other deflections in bedding which have smaller limb lengths and overall amplitude do occur and have similar dips. These steep limb dips reflect local accommodation of high strain which correspond with hydrothermal fluid flow and gold mineralization.
The two most prominent areas of gold bearing veins are at Razorback and Margarethental with clustered sets of quartz veins which could be controlled by underlying shear zones that appear to step in an en-echelon pattern in the Geolex North area (Figure 2).
Figure 2: Ondundu Main Zone and Common Limb (Source: B2Gold mapping and interpretation data)
Mineral Resource Estimate
The Ondundu deposit is known for its coarse, nuggety gold mineralization, which gives rise to narrow high grade gold intersections. The style of gold mineralization at Ondundu, hosted primarily within narrow quartz carbonate veins, is thus quite different to the broad disseminated nature of the mineralization at the Twin Hills Gold Deposit. The narrow gold intersections at Ondundu are inherently difficult to model in three dimensions, unlike the wide and more coherent nature of mineralization at Twin Hills. Like many similar coarse gold deposits, sampling at Ondundu requires routine screen fire assays and will benefit from large sample volumes to adequately capture the coarse and irregular nature of the gold.
It is noteworthy that most of the drillholes used in this Maiden Mineral Resource Estimate for Ondundu are from diamond core drilling of a relatively small core diameter, specifically NQ core size with a nominal core diameter of 47.6mm. The uncertainty in the modelling at Ondundu is therefore amplified by the small sample volumes, as well as the relatively low drilling density available at present.
Osino believes that larger sample volumes and increased drilling density may improve the confidence in the modelling and has the potential to improve the overall resource. Consequently, additional large diameter reverse circulation and larger (HQ) core diameter drilling will commence on the project later this year.
Figure 3: Plan view showing part of the drilling database indicated by collar location and type in the Ondundu area
B2Gold did assess this to some extent, but only drilled 2 twin RC holes (1 each at Margarethental & Razorback) and concluded: “… RC is less sensitive to grade variability in the upper and lower grade range, this potentially could have advantages in modelling the deposit due to potentially better grade continuity with RC.”
Gold mineralization was interpreted and modelled from a combination of structural and assay data for each of the Ondundu mineralization domains (Figure 3). The shear zone mineralization, hosted in sandstones, siltstones and a mix thereof, dips from 80° east to vertical and ranges from a few meters to 50m in thickness.
The bedding plane mineralization is less continuous and parallel to the local bedding plane (255° dip direction at 60° dip) within the Common Limb. A 0.4g/t Au threshold was used to manually code mineralized intersections into either shear zone or bedding plane mineralization. The modelled mineralization includes mineralized intersections, with the geometry guided by local structural trends.
The cross sections depict the mineralization at the two main targets, Razorback and Margarethental (Figure 4). The cross sections are oriented to align with the plane of the closest-spaced drilling and to illustrate the geometry and orientation of the mineralization.
The mineral resource reporting pit shell at US$1800/oz is included in the sections below for reference purposes (Figure 5 and Figure 6). The conceptual pit shell represents reasonable prospects for eventual economic extraction (RPEEE) by open pit mining.
Figure 5: Razorback section looking north showingmineralization and coded intersections (refer toFigure 4)
Figure 6: Margarethental section looking northshowing mineralization and coded intersections (refer to Figure 4)
Gold grade was estimated using ordinary kriging from 2m composites into 25m x 25m x 5m (XYZ) blocks. Estimated grades were validated by means of global statistics and swath analyses. Bulk density was determined using an Archimedes-type technique on core and assigned to the model based on oxidation/weathering such that oxidized material was assigned a density of 2.60 t/m3, transitional material 2.67 t/m3 and fresh rock 2.75 t/m3.
Reasonable Prospects for Eventual EconomicExtraction
CIM Definition Standards for Mineral Resources and Mineral Reserves states that a mineral resource is a concentration or occurrence of solid material of economic interest in or on the Earth’s crust in such form, grade or quality and quantity that there are reasonable prospects for eventual economic extraction (RPEEE).
To satisfy the requirement of RPEEE by open pit mining, reporting pit shells were determined based on conceptual parameters and costs and assuming a gold price of US$1800/oz. Based on preliminary test work results, gold recovery is planned to be achieved by crushing, coarse milling, gravity separation and intensive leaching of gravity concentrate. The lateral extent of the reporting pit shells and gold grade distribution in the resource block model is shown in the diagram below (Figure 7).
Figure 7: Plan view showing material in theUS$1800/oz reporting pit shell above 0.5g/t Au
Mineral Resource Classification
Material within the reporting pit shell was classified according to mineral resource confidence categories defined in CIM Definition Standards for Mineral Resources and Mineral Reserves. Data quality and quantity, geological and grade continuity, and confidence in the grade and density estimates were considered when classifying the mineral resource.
The mineral resource is classified as Inferred and is classified up to a drill spacing of 100m on strike and 50m on section, although the main areas of Razorback and Margarethental are typically supported by drilling spaced at 25m x 25m and 50m x 25m respectively. No mineral resource is classified more than 50m beyond the last line of drilling. It is reasonable to expect that the majority of Inferred mineral resources could be upgraded to Indicated mineral resources with infill drilling.
Mineral Resource Statement
The mineral resource is that material within the US$1800/oz reporting pit shell above a 0.5g/t Au cut-off grade. The mineral resource estimate has an effective date of 7 October 2022 (Table 2), and a corresponding technical report disclosing the mineral resource estimate in accordance with NI 43- 101 will be prepared by CSA Global (Pty) Ltd for the Company. The Company will file the technical report on SEDAR under its profile at www.sedar.com within 45 days of the date of this news release.
Table 2: Mineral Resource for the Ondundu GoldProject at a 0.5 g/t Au cut-off as at 7 October 2022
Notes on mineral resource reporting:
- Figures have been rounded to the appropriatelevel of precision for the reporting of mineralresources.
- Mineral resources are stated as in situ drytonnes. All figures are in metric tonnes.
- The mineral resource has been classified under the guidelines of the CIM Definition Standards for Mineral Resources and Mineral Reserves and adopted by the CIM Council, andprocedures for classifying the reported mineral resources were undertaken within the context of the Canadian Securities Administrators NI 43-101.
- The mineral resource is reported within aconceptual pit shell determined using a goldprice of US$1,800/oz and conceptualparameters and costs to support assumptions relating to reasonable prospects for eventual economic extraction:
- 4% royalty (3% government royalty and1% export levy)
- Selling costs of US$2.75/oz
- Mining costs of US$2.00/t ore andUS$1.85/t waste, with additional costattributed to depth below surface
- Processing and rehandling costs ofUS$8.15/t run of mine ore
- G&A cost of US$4.00/t run of mine ore
- Slope angle of 48° in weathered rock and55° in fresh rock
- 90% gold recovery from CIL circuit
- Mineral resources that are not MineralReserves do not have demonstrated economicviability.
Cut-off Grade Variation
The estimated block model was tabulated at various cut-off grades (Table 3). This tabulation does not represent a mineral resource in any way and only serves to illustrate the nature of the mineralization and sensitivity to various cut-offs.
Table 3: Classified block model within theUS$1800/oz reporting pit shell at various cut-offgrades
|Cut-Off Grade||Tonnes||Grade||Troy Ounces|
|(g/t Au)||(millions)||(g/t Au)||(millions)|
Gold Price Sensitivity
The estimated block model was subject to RPEEE scenarios at various gold prices (Table 4). This tabulation does not represent a mineral resource in any way and only serves to illustrate the sensitivity of gold price on the RPEEE pit shell.
Table 4: RPEEE sensitivity relative to gold price at a 0.5 g/t Au cut-off
|Gold Price||Tonnes||Grade||Troy Ounces|
Osino collected mineralised material from multiple Ondundu cores and combined 24 such samples into eight bags which were subsequently combined further into two composite samples, for gravity tests conducted in Johannesburg. The aim was to generate two composites with significant differences in gold grade and mineralogy, and this objective was achieved.
After comprehensive assays of the two samples, extended gravity recovery gold evaluation (EGRG) tests were carried out according to the following procedure. Gold recovery at each stage of milling as well as ultimate gold recovery to concentrate was recorded.
The raw test results were modelled by Gravity Concentrators Africa (GCA) using a simulation package to predict the likely recovery of gold in a commercial installation using primary jigging of relatively coarse material followed by centrifugal concentrators in closed circuit with a mill. The modelling of results from the tests conducted on the two samples suggested that after milling to 80% passing 75 micron, gold recovery in the range of 70-80% to gravity concentrate (containing less than 2% of the solid feed to the circuit) could be achieved.
GCA’s report noted that further work will be needed at a later stage of development to ensure that the samples for this preliminary testwork were representative.
Quality Assurance / Quality Control
The assay data derived from B2Gold drilling campaigns were verified by means of QA/QC which included the insertion of certified reference materials, blanks, and duplicates into sample batches sent for sample preparation and analysis. The results of the QAQC program were reviewed by the QP. Use of the geological data for mineral resource estimation and reporting is approved by the QP.
Qualified Person’s Statement
The mineral resource estimate was carried out by Mr. Anton Geldenhuys (MEng), a registered Professional Natural Scientist (SACNASP, membership number 400313/04) of CSA Global (Pty) Ltd., who is an independent Qualified Person (QP) as defined by CIM Definition Standards for Mineral Resources and Mineral Reserves in accordance with NI 43-101. Mr. Geldenhuys is a geoscientist and is qualified as a geologist (Honours) and engineer (Masters) and has over 21 years of relevant industry experience. Mr. Geldenhuys is a member in good standing of the South African Council for Natural Scientific Professions (SACNASP) and has sufficient experience relevant to the commodity, style of mineralization and activity which he is undertaking to qualify as a QP under NI 43-101. Mr. Geldenhuys has reviewed and approved the scientific and technical information in this news release.
About Osino Resources
Osino is a Canadian gold exploration and development company focused on the fast-tracked development of our Twin Hills Gold Project (“Twin Hills”) in central Namibia. Twin Hills is at an advanced stage of exploration and development with more than 220,000m of drilling completed on the project since its grassroots discovery by Osino with various advanced development studies underway.
Osino has a large ground position of approximately 6,900km2 located within Namibia’s prospective Damara sedimentary mineral belt, mostly in proximity to and along strike of the producing Navachab and Otjikoto Gold Mines. The Company is actively exploring a range of gold prospects and targets along the belt by utilizing a portfolio approach geared towards discovery, targeting gold mineralization that fits the broad orogenic gold model.
Our core projects are favorably located north and north-west of Namibia’s capital city Windhoek. By virtue of their location, the projects benefit significantly from Namibia’s well-established infrastructure with paved highways, railway, power and water in close proximity. Namibia is mining-friendly and lauded as one of the continent’s most politically and socially stable jurisdictions. Osino continues to evaluate new ground with a view to expanding our Namibian portfolio.
Further details are available on the Company’s website at https://osinoresources.com/
On Behalf of The Board of Directors
Chief Executive Officer, President, and Director
Osino Resources Corp.
Julia Becker: Investor Relations Manager
Tel: +1 (604) 785 0850
Cautionary Statement Regarding Forward-Looking Information
This press release contains “forward-looking information” within the meaning of applicable Canadian securities legislation. Forward-looking information includes, without limitation, statements regarding the use of proceeds from the Company’s future plans or prospects of the Company, including prospects for economic recoverability of mineral resources. Generally, forward-looking information can be identified by the use of forward-looking terminology such as “plans”, “expects” or “does not expect”, “is expected”, “budget”, “scheduled”, “estimates”, “forecasts”, “intends”, “anticipates” or “does not anticipate”, or “believes”, or variations of such words and phrases or state that certain actions, events or results “may”, “could”, “would”, “might” or “will be taken”, “occur” or “be achieved”. Forward-looking statements are necessarily based upon a number of assumptions that, while considered reasonable by management, are inherently subject to business, market and economic risks, uncertainties and contingencies that may cause actual results, performance or achievements to be materially different from those expressed or implied by forward-looking statements. Although the Company has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking information, there may be other factors that cause results not to be as anticipated, estimated or intended. There can be no assurance that such information will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking information. Other factors which could materially affect such forward-looking information are described in the risk factors in the Company’s most recent annual management’s discussion and analysis which is available on the Company’s profile on SEDAR at www.sedar.com. The Company does not undertake to update any forward- looking information, except in accordance with applicable securities laws.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this press release.