Wrap Text
Orion updates Mineral Resources at the Flat Mines Area, Okiep Copper Project
Orion Minerals Limited
Incorporated in the Commonwealth of Australia
Australian Company Number 098 939 274
ASX share code: ORN
JSE share code: ORN
ISIN: AU000000ORN1
Orion updates Mineral Resources at the Flat Mines Area, Okiep Copper Project
Other historical mines and prospects also being modelled, with potential to deliver further resource growth
• A review of the geological interpretation at Flat Mine (Nababeep), including eight holes drilled by Orion,
has resulted in improved definition of the mineralised zones.
• Mineral Resources at Flat Mine (Nababeep) are 0.6 Mt at 1.0% Cu for 6,000 tonnes of contained copper,
comprising an Indicated Resource of 0.3 Mt at 1.07% Cu and an Inferred Resource of 0.3 Mt at 1.0% Cu.
• This brings the total Mineral Resources within the Flat Mines Area of the Okiep Copper Project to 11.5 Mt
at 1.3% Cu for 152,000 tonnes of contained copper.
• Previously announced Mineral Resources were 9.4 Mt at 1.3% Cu for Flat Mine North, Flat Mine East and
Flat Mine South and 1.5 Mt at 1.3% Cu for Jan Coetzee Mine and Nababeep Kloof Mine.
• Other historical mines and prospects are currently being modelled, with the potential to deliver further
growth in the OCP Mineral Resource.
Orion's Managing Director and CEO, Errol Smart, commented:
"Confidence in the Flat Mines Mineral Resource estimate has been improved by recent drilling and the Flat Mine
Nababeep Mineral Resource is modelled for consideration as an underground mining project with large open
stopes including significant internal dilution.
"Our success in Mineral Resource estimation at Flat mines, following our validation drilling is providing growing
confidence in the extensive historical Newmont and Goldfields data that we acquired for the Okiep District.
Ongoing digitisation and modelling is allowing us to rank the surrounding mineralised bodies and consider
Reasonable Expectation of Eventual Economic Extraction with the objective of targeting bodies with qualities
that could provide rapid growth in production scale and extension of mine life for prioritised infill and validation
drilling.
"This report is the culmination of an intense twelve-month program and has been a very valuable demonstration
of the ability to rapidly establish Mineral Resources in a rapidly executed, cost effective drilling program. We
have several mineralised bodies with similar historical scale and density of historic drilling that we are prioritising
for similar programs as just completed."
Orion Minerals Limited (ASX/JSE: ORN) (Orion or Company) is pleased to report an update in the Mineral Resource
estimate for Flat Mine (Nababeep) (FMNb) that forms part of the Okiep Copper Project (OCP), located in the
Northern Cape Province of South Africa, following a detailed review of the geology and remodelling of the
deposit.
The Indicated and Inferred Mineral Resources, as stated in Table 1 below, have been re-estimated for the FMNb
deposit, and now are 0.6 Mt grading 1.0% Cu for 6,000 tonnes of contained copper (Table 1).
Together with the previously reported Mineral Resources for Flat Mine North (FMN), Flat Mine East (FME) and Flat
Mine South (FMS) (refer ASX/JSE release 28 August 2023) of 9.4 Mt grading 1.3% Cu including a Measured and
Indicated Mineral Resource of 7.4 Mt grading 1.35% Cu (Table 2) and an Inferred Mineral Resource for Jan
Coetzee Mine and Nababeep Kloof Mine (refer ASX/JSE release 29 March 2021) of 1.5 Mt grading 1.3% Cu (Table
2), this latest resource estimate revises the total Mineral Resource at the OCP to 11.5 Mt grading 1.3% Cu for
152,000 tonnes of contained copper (Table 2). The total Measured and Indicated Mineral Resource at the OCP
has increased from 7.4 Mt grading 1.35% Cu to 7.7 Mt grading 1.34% Cu.
The Mineral Resource estimation is based on historical drilling data and Orion drill holes and is estimated by a
Competent Person and classified in accordance with the 2012 Edition of the Australian Code for Reporting of
Exploration Results, Mineral Resources and Ore Reserves (JORC Code (2012)) with supporting information in
Appendices 1 and 2.
Updated FMNb Mineral Resource
Following an extended period of detailed review resulting in an increased understanding of the local geology
and the controls on mineralisation, a new interpretation was completed for the FMNb deposit. The new
interpretation has significantly improved the definition of the estimation domains at FMNb and has due
consideration of JORC Code (2012) guidelines for requirements of RPEEE (Reasonable Prospects of Eventual
Economic Extraction) using underground mining methods for the more diluted but continuous blocks.
The changes to the resource models decreased the total Mineral Resource at FMNb from 1.0 Mt (Inferred
category) grading 1.4% Cu (refer ASX/JSE release 29 March 2021) to 0.6 Mt grading 1.0% Cu, including Indicated
Resources of 0.3 Mt grading 1.07% Cu and Inferred Resources of 0.3 Mt grading 1.0% Cu. This change is a direct
result of adjustments to the resource model due to the increase in understanding of the geology and
mineralisation models.
The FMNb Mineral Resource shown in Table 1 is based on drilling data available for the Flat Mines Southern African
Tantalum Mining (Pty) Ltd (SAFTA) Mining Right NC30/5/1/2/2/10150MR (refer ASX/JSE releases 29 March 2021, 3
September 2024, 17 December 2024). The Mineral Resources are reported in accordance with the JORC Code
(2012), with supporting information provided in Appendices 1 and 2.
Several other historical mines and prospects are currently being modelled, with the potential to deliver further
growth in the OCP Mineral Resource.
Table 1: Mineral Resource Statement for the Flat Mine (Nababeep).
Measured Indicated Inferred
Mine / Prospect
Tonnes % Cu t Cu Tonnes % Cu t Cu Tonnes % Cu t Cu
Flat Mine (Nababeep) - - - 300,000 1.07 3,000 300,000 1.0 3,000
*Numbers may not add up due to rounding in accordance with the JORC Code (2012) guidance.
Resources are reported at a 0.5% Cu cut-off grade.
Figure 1: SAFTA prospecting and mining rights showing prospects with previously reported (yellow) and updated (grey) Mineral Resources.
Table 2: Total Mineral Resource Statement for the Flat Mines Area of the OCP.
Measured Indicated Inferred
Mine / Prospect
Tonnes % Cu t Cu Tonnes % Cu t Cu Tonnes % Cu t Cu
Flat Mine (Nababeep) - - - 300,000 1.07 3,000 300,000 1.0 3,000
Jan Coetzee Mine - - - - - - 1,000,000 1.4 14,000
Nababeep Kloof Mine - - - - - - 500,000 1.2 6,000
Flat Mine North 440,000 1.13 5,000 940,000 1.42 13,000 200,000 1.5 4,000
Flat Mine East - - - 3,400,000 1.37 47,000 1,000,000 1.0 9,000
Flat Mine South - - - 2,600,000 1.35 35,000 800,000 1.6 13,000
Total 440,000 1.13 5,000 7,200,000 1.36 98,000 3,900,000 1.3 49,000
*Numbers may not add up due to rounding in accordance with the JORC Code (2012) guidance.
Resources are reported at a 0.7% Cu cut-off grade for FMN, FME, FMS, Jan Coetzee and Nababeep Kloof. Resources are reported at a
0.5% Cu cut-off grade for FMNb.
Geology and Geological Interpretation
The Okiep copper deposits are orogenic-type copper deposits hosted in mafic to ultra-mafic intrusive bodies in
the western part of the Namaqua Complex, South Africa. Mines in the Okiep Copper District (OCD) produced
106 Mt at 1.7% Cu since the 1900s1. Production in the OCD came from both underground and surface workings.
Copper deposits in the Okiep district are generally hosted by east-trending mafic/ultramafic dykes and sills. Some
1,700 of these intrusions occur in the district. A structural control on intrusives in the form of 'steep structures' or
monoclinal folds is well established. Copper mineralisation occurs as disseminations of chalcopyrite and bornite
with local massive sulphide concentrations within and adjoining mafic intrusive bodies.
Mineralisation at FMNb is hosted by shallow, sub-surface bodies within a continuous mafic intrusive. The
mineralised bodies have an overall strike of 270m and a steep dip of 80° towards the north to vertical. The
mineralised bodies are offset by two faults, the FMNb West Fault and the FMNb East Fault. The West Fault has a
dip of approximately 65° to the east and the East Fault has a dip of approximately 65° towards the west. The two
faults converge at a depth of approximately 210m, effectively terminating the known mineralisation (Figure 2).
The bulk of the known mineralisation is located between the two faults and is referred to as the Main Mineralised
Zone with a strike at surface of approximately 200m and an average width of around 25m. The mineralised body
is offset 60m to the south by the West Fault where mineralisation appears to narrow to approximately 5m width
and extends approximately 30m beyond the fault. The East Fault offsets the mineralisation approximately 35m to
the north in a sinistral sense, where it extends eastwards at an average width of approximately 10m. The
mineralisation east of the East Fault has a short strike on surface of approximately 10m but the strike extends to
approximately 100m downdip due to the shallow west dip of the East Fault (Figure 2).
The deposit was mined in the Main Mineralised Zone in the 1950s, accessed by a 155m deep, 3m by 2m sized
vertical shaft, and five main levels of development 100 feet (approximately 30m) apart. A larger eastern stope
and a smaller western stope, according to historical production reports, extracted 141,000 tonnes of ore material
(refer ASX/JSE release 29 March 2021).
Drilling Techniques
Drilling at FMNb was undertaken during two distinct periods: from 1947 to 1978 by O'Okiep Copper Company
(OCC) and in 2024 by Orion.
A total of 55 surface diamond drill holes totalling 15,263m and 116 holes underground diamond drill holes
comprising 2,785m are captured in the historical drilling database. All historical drilling was at AX core size.
A further nine NQ diamond drill holes totalling 959.47m were drilled by Orion in 2024 (refer ASX/JSE releases 17
December 2024 and 3 September 2024 2). Eight of these holes were targeted on the known mineralisation, while
one hole (OFMD170) was targeted on a geophysical anomaly. The eight holes intersecting the mineralisation
were used to update the geological interpretation and were used in the update of the Mineral Resource
estimate.
Sampling and Sub-Sampling Techniques
Historical OCC diamond drill holes were sampled as whole core. There is limited information available on
sampling techniques. Samples were taken over two-metre intervals adjusted to accommodate geological
contacts. OCC submitted whole core to the laboratory, except for a 5-10cm piece of core left as a reference.
Sampling was carried out under the supervision of OCC geologists.
Historical samples were prepared at the OCC on-mine laboratory in Nababeep. No official records are available
for laboratory procedures for the OCC laboratory. Core samples were reportedly crushed and split prior to
1Lombaard A.F,, in Annhauser C.R., and Maske S. (eds). The Copper Deposits of the Okiep Copper District, Namaqualand in Mineral Deposits
of Southern Africa. 1982 pp 1421 - 1445.
2 Orion's 2024 Flat Mines drilling information is extracted from the reports entitled 'Okiep Confirmation Drilling Successfully Completed' and
'Strong New Copper Intercepts Indicate Significant Additional Potential of Flat Mine South – Okiep Project' dated 3 September 2024 and 17
December 2024, respectively, and available to view on https://www.orionminerals.com.au/download-category/2024-asx-jse-
announcements/. Orion confirms that it is not aware of any new information or data that materially affects the information included in the
original market announcement. Orion confirms that the form and context in which the Competent Person's findings are presented have not
been materially modified from the original market announcement.
analysis. In the Competent Person's opinion, the sampling and sub-sampling are fit for the purpose of classifying
an Indicated and Inferred Mineral Resource. The OCC successfully operated copper mines in the district for more
than 50 years and had a proven record of converting resources to reserves.
Orion's 2024 sampling was carried out using industry-standard procedures. NQ-size diamond drill cores were
longitudinally split in half using a diamond core cutting machine. Half core was cut to quarter core where
duplicates were taken. One-metre sample lengths were taken in most cases in the mineralised zones, with two-
metre sample lengths generally taken in poorly mineralised zones and sections of internal waste. Sample lengths
were varied to honour geological and mineralisation boundaries.
Sample Analyses
Historical OCC drill samples were analysed at the OCC on-mine laboratory in Nababeep. No official records are
available for laboratory procedures for the OCC laboratory. Core samples were reportedly assayed for copper
content by atomic absorption techniques. No certified reference material, blanks and duplicates were inserted,
however the OCC laboratory inserted in-house standard reference material with each batch. In the Competent
Person's opinion, the sample analyses are fit for the purpose of classifying an Indicated and Inferred Mineral
Resource.
All 2024 Orion drill samples were analysed by an appropriate high-grade aqua regia ICP-AES method, ALS code
ME-ICP41a. Samples where assays returned >5% Cu were re-assayed by aqua regia digestion and ICP-AES
method, ALS code MEOG-46. Samples were assayed for gold by fire assay and AAS, ALS code AU-AA25 method.
Appropriate quality control was undertaken, and the accuracy and precision of the geochemical data is
considered acceptable. In the Competent Person's opinion, the sample analyses are fit for the purpose of
classifying an Indicated and Inferred Mineral Resource.
Estimation Methodology
The following estimation methods were applied:
• Mineralisation often occurs as discrete mineralised lenses within and normally following the general trend
of a broader mafic intrusive body. With the irregular intrusive nature of the mafic rocks and mineralisation
it can be difficult to correlate individual lenses between sections and drill holes and in many cases
modelling of estimation domains was only feasible by grouping the lenses into a broader envelope
including internal waste and resulting in a lower copper grade.
• Estimation domains were delineated by creating interpreted strings along successive vertical sections. A
0.5% Cu cut-off grade was selected for the outer limit of the estimation domain. From visual observation,
using a cut-off grade above 0.5% Cu, the mineralisation lacks the required continuity to construct a viable
domain for resource estimation and, as a result, significant portions of internal waste have been included
in the mineralisation envelope.
• In addition, in some areas, the 0.5% Cu cut-off was lowered (often in sections where all grades are below
0.5% Cu but still anomalous and in the mafic lithologies associated with the mineralisation) in order to
maintain continuity and a viable domain for resource estimation. Modelling of internal 'waste pillars'
(mostly associated with granitic inclusions within the mafic bodies) as a separate domain for estimation
was not possible due to difficulties in correlating internal waste zones between drill holes over any significant
distance.
• Extrapolation distances were maintained at halfway between drill holes with mineralisation above the cut-
off grade and drill holes where no significant mineralisation was intersected, or terminated at modelled
structures. With the generally high density of drill hole information this extrapolation distance did not exceed
15m.
• Many of the internal waste zones in the historical drill holes are unsampled and have been assigned a value
of half the detection limit.
• No differentiation was made between the oxide and sulphide mineralisation as generally the oxide
component is insignificant within the Flat Mines deposits. The oxides extend to a depth of approximately
4m on average.
• Copper assay values were capped to 10% Cu and this was applied to 3 samples. Sample lengths were
composited to 1m. A block model with cell sizes of 2m (X) x 2m (Y) and 2m (Z) was used with no sub-celling.
The composite data were used to estimate the block grades using Inverse Distance Squared (IDW²).
• The mineralised zone was separated into three domains:
- West of the West Fault.
- The Main Mineralised Zone between the West Fault and the East Fault.
- East of the East Fault.
• Search ellipses of dimensions 60m x 60m x 10m oriented in line with the general strike for each of the three
domains were used to estimate blocks in each domain. The search ellipse size was guided by the range of
the variogram. A minimum of two drill holes was required for block estimation.
• Bulk Densities (t/m3) for Orion drill holes were determined using the water displacement method. There
were no bulk densities measured for historical holes. Densities were assigned to the historical holes by proxy
to lithological units using measurements from Orion holes at FMNb, FMN, FME and FMS. Block densities were
calculated using IDW². The orientation and radius of the search ellipse used was the same as for copper.
In the Competent Person's opinion, the estimation methodologies are suitable for the type of deposit and nature
of the data and can be used to classify the estimate in accordance with the JORC Code (2012).
Resource Classification
The Resource classification has been carried out in accordance with the JORC Code (2012).
The resources are classified as Indicated and Inferred. Cognisance was taken of the potential uncertainties
related to mineralised envelope delineation and therefore the associated volume estimation, as well as that this
resource estimation is partly based on historical data.
The resource classification has increased relative to the previous FMNb Mineral Resource (Refer ASX Release 29
March 2021) in areas tested by Orion's 2024 confirmation drilling.
The geological models are considered by the Competent Person to be defined to an acceptable level and
there is sufficiently accurate data to produce block estimates. In areas where there is a limited number of
samples resources are defined as Inferred.
With the relatively high density of information, extrapolation for both Indicated and Inferred Resources was at
the halfway point between drill holes with mineralisation above the cut-off grade and drill holes where no
significant mineralisation was intersected or terminated at modelled structures. With the generally high density
of drill hole information this extrapolation distance did not exceed 15m. The differentiation between Indicated
and Inferred Resources was largely based on the coverage of Orion 2024 drill holes and the proximity of historical
underground workings (Figure 3).
Although there is a moderate level of uncertainty associated with the estimation of bulk densities at FMNb,
the common lithologies associated with the mineralisation have a relatively narrow range of density values.
Areas in the Main Mineralised Zone above the historical mine workings were defined as Indicated. There are six
Orion holes spread along the 200m strike which intersected mineralisation and broadly confirmed the zones and
grades defined by the historical drilling.
Areas in the Main Mineralised Zone below the upper limits of historical mine workings were defined as Inferred.
While there is a good density of historical drill hole information, and development and stopes have been defined
for depletion purposes, none of the Orion drill holes intersected this area. Furthermore, historical workings are
based on 1950s information and have limitations in accuracy and while the host formations are competent, there
may be a degree of caving or scaling from the historical stopes.
West of the West Fault, there are no Orion drill holes and a lower density of historical information and this area
was defined as Inferred. East of the East Fault there is a higher density of historical information and two Orion drill
holes, and this area was defined as Indicated.
Twin and infill drilling will be required to increase the confidence and upgrade the Inferred Resources. Drilling
should also include probe holes to investigate the extent of the underground workings, all in the area of Inferred
Resources. The results conform to the view of the Competent Person.
Cut-off Grades
A cut-off grade of 0.5% Cu was used for the Mineral Resource Statement that corresponds with RPEEE using
today's economics. This is based on the break-even grade estimated for the 2025 Definitive Feasibility Study (DFS)
study released contemporaneously with this report.
Mining, Metallurgical Methods and Modifying Factors
The deposit is considered suitable for potential underground mining operations.
Historically mined areas (stopes) shown on mine survey plans were excluded from the resource. 141,000 tonnes
of ore are recorded to have been historically mined (refer ASX/JSE release 29 March 2021).
No historical metallurgical test results are available. However, the geology and mineralisation at FMNb is of a
similar style to other deposits in the immediate vicinity (FMN, FME, FMS) where extensive metallurgical testwork
has been done and will be reported in the current DFS.
Future Activities
Some twin and in-fill drilling will be required to increase the confidence and upgrade the Inferred Resources.
For and on behalf of the Board.
Errol Smart
Managing Director and CEO
28 March 2025
ENQUIRIES
Investors Media JSE Sponsor
Errol Smart – Managing Director & Nicholas Read Monique Martinez
CEO
Denis Waddell – Chairman Read Corporate, Australia Merchantec Capital
T: +61 (0) 3 8080 7170 T: +61 (0) 419 929 046 T: +27 (0) 11 325 6363
E: info@orionminerals.com.au E: nicholas@readcorporate.com.au E: monique.martinez@merchantec.com
Competent Persons Statement
The information in this report that relates to Mineral Resources is based on information compiled by Mr Paul Matthews
(Pr.Sci.Nat.), a Competent Person who is a member of the South African Council for Natural Scientific Professionals, a
Recognised Professional Organisation (RPO). Mr Matthews is a full-time employee of Orion. Mr Matthews has sufficient
experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being
undertaken to qualify as a Competent Person as defined in the 2012 Edition of the JORC Code. Mr Matthews consents to the
inclusion in this announcement of the matters based on his information in the form and context in which it appears.
References to Previous Reports
Information on the Flat Mine North (FMN), Flat Mine East (FME), and Flat Mine South (FMS) Mineral Resources is extracted from
the report entitled 'Orion upgrades Mineral Resources at the Flat Mines Area, Okiep Copper Project as BFS nears completion'
dated 28 August 2023 and available to view on https://www.orionminerals.com.au. Orion confirms that it is not aware of any
new information or data that materially affects the FMN, FME and FMS Mineral Resources included in the original market
announcement and that all material assumptions and technical parameters underpinning the estimates in the relevant
market announcement continue to apply and have not materially changed. Orion confirms that the form and context in
which the Competent Person's findings are presented have not been materially modified from the original market
announcement.
Information on the Jan Coetzee Mine and Nababeep Kloof Mine Mineral Resources is extracted from the report entitled
'Orion further expands Mineral Resources at the Okiep Copper Project, Flat Mines Area' dated 29 March 2021 and available
to view on https://www.orionminerals.com.au. Orion confirms that it is not aware of any new information or data that
materially affects the Jan Coetzee Mine and Nababeep Kloof Mine Mineral Resources included in the original market
announcement and that all material assumptions and technical parameters underpinning the estimates in the relevant
market announcement continue to apply and have not materially changed. Orion confirms that the form and context in
which the Competent Person's findings are presented have not been materially modified from the original market
announcement.
Disclaimer
This release may include forward-looking statements. Such forward-looking statements may include, among other things,
statements regarding targets, estimates and assumptions in respect of metal production and prices, operating costs and
results, capital expenditures, mineral reserves and mineral resources and anticipated grades and recovery rates, and are or
may be based on assumptions and estimates related to future technical, economic, market, political, social and other
conditions. These forward-looking statements are based on management's expectations and beliefs concerning future
events. Forward-looking statements inherently involve subjective judgement and analysis and are necessarily subject to risks,
uncertainties and other factors, many of which are outside the control of Orion. Actual results and developments may vary
materially from those expressed in this release. Given these uncertainties, readers are cautioned not to place undue reliance
on such forward-looking statements. Orion makes no undertaking to subsequently update or revise the forward-looking
statements made in this release to reflect events or circumstances after the date of this release. All information in respect of
Exploration Results and other technical information should be read in conjunction with Competent Person Statements in this
release (where applicable). To the maximum extent permitted by law, Orion and any of its related bodies corporate and
affiliates and their officers, employees, agents, associates and advisers:
• disclaim any obligations or undertaking to release any updates or revisions to the information to reflect any change in
expectations or assumptions;
• do not make any representation or warranty, express or implied, as to the accuracy, reliability or completeness of the
information in this release, or likelihood of fulfilment of any forward-looking statement or any event or results expressed
or implied in any forward-looking statement; and
• disclaim all responsibility and liability for these forward-looking statements (including, without limitation, liability for
negligence).
The Orion Mineral Resources updates at the Flat Mines Area Okiep Copper Project, including supporting information
provided in Appendix 1 and 2 thereof, is available on Orion's website at:
https://www.orionminerals.com.au/download-category/2025-asx-jse-announcements/
Date: 28-03-2025 12:35:00
Produced by the JSE SENS Department. The SENS service is an information dissemination service administered by the JSE Limited ('JSE').
The JSE does not, whether expressly, tacitly or implicitly, represent, warrant or in any way guarantee the truth, accuracy or completeness of
the information published on SENS. The JSE, their officers, employees and agents accept no liability for (or in respect of) any direct,
indirect, incidental or consequential loss or damage of any kind or nature, howsoever arising, from the use of SENS or the use of, or reliance on,
information disseminated through SENS.
Sharenet Sites 
