REG - Rockfire Resources - Maiden JORC Resource at Molaoi
23/05/2022 07:00
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RNS Number : 3995M Rockfire Resources PLC 23 May 2022
The information contained within this announcement is deemed by the Company to
constitute inside information pursuant to Article 7 of EU Regulation 596/2014
as it forms part of UK domestic law by virtue of the European Union
(Withdrawal) Act 2018 as amended.
23 May 2022
Rockfire Resources plc
("Rockfire" or the "Company")
Maiden JORC Resource at Molaoi exceeds expectations
Rockfire Resources plc (LON: ROCK), the gold and base metal exploration
company, is pleased to announce a maiden Mineral Resource estimate ("Mineral
Resource") at its 100%-owned Molaoi zinc deposit in Greece. The Mineral
Resource has surpassed all expectations and demonstrates the quality and
potential of the project.
The resource is reported in accordance with the Joint Ore Reserve Committee
("JORC") Australasian Code (2012) for Reporting of Exploration Results,
Mineral Resources and Ore Reserves.
Highlights
· The inaugural JORC resource estimation for Molaoi has delivered an
Inferred Mineral Resource of:
2.3 million tonnes @ 11 % ZnEq. for 250,000 tonnes of ZnEq.
· This resource uses a 4% low-grade cut, with individual elemental
grades of 9.4 % Zn, 1.7 % Pb and 47 g/t Ag.
· Molaoi currently contains 210,000 tonnes of zinc, 39,000 tonnes of
lead, and 3.5 million ounces of silver.
· Only 1,400 m of a potential strike extent of 7 km has been included
in the resource and the resource remains open at depth and along strike.
· Multiple, parallel mineralised lodes, which are not included in the
resource, are yet to be fully tested. The images of the resource model, which
can be viewed via the link below, demonstrate the quality of zinc intercepts
in parallel lodes which may add materially to the resource in future
estimates.
· Metallurgical flotation test work completed in 1984 resulted in 96%
zinc recovery, 92% lead recovery and 91% silver recovery into a bulk
concentrate. These recovery factors have been applied to the Mineral Resource
to calculate the resulting zinc equivalent tonnes and grade.
· Mineralisation starts at surface. Despite this, and to ensure a
practical estimate is delivered, the top 40 m has been excluded from the
Mineral Resource. Rockfire is planning underground mining only to minimise
social and environmental impacts.
· As mentioned in the Company's RNS on 10 May 2022, one of the world's
critical metals, germanium, is present at potentially commercial grades.
Germanium has not been included in the resource estimate owing to limited
quantitative analysis.
· Molaoi has a capped portal and 700 m long decline which, if
refurbished, may permit access to the top of the sulphide mineralisation.
Molaoi lies within 10 km of the coast, providing excellent access to potential
markets.
· Rockfire plans to undertake resource delineation and extensional
drilling over the next 12 months.
A plan, cross section and long section of the resource model can be viewed by
following the link provided here.
http://www.rns-pdf.londonstockexchange.com/rns/3995M_1-2022-5-23.pdf
(http://www.rns-pdf.londonstockexchange.com/rns/3995M_1-2022-5-23.pdf)
David Price, Chief Executive Officer of Rockfire, commented:
"Our maiden JORC Mineral Resource for Molaoi represents a pivotal milestone
for Rockfire. Management considers Molaoi to be an outstanding base metal
project, which we hope will grow to a globally significant scale. The quality
of the grades and quantity over the first 1,400 m strike extent is testimony
to the potential size of Molaoi, particularly if our planned exploration along
strike proves to be successful.
"We intend to test the entire 7 km of strike which, if similarly mineralised,
could potentially result in a resource much larger than the maiden resource.
Several historical holes drilled along this 5.5 km extension have intersected
high grade zinc, so we know already that zinc is present.
"The project is at an advanced stage, with 173 cored holes having already been
drilled. Resource delineation and extension drilling can commence quickly,
with most preliminary surface exploration techniques having already been
completed by the Greek government. We are working on obtaining the necessary
permits to commence our drilling at Molaoi as quickly as possible.
"Rockfire now has a significant inventory of 100%-owned JORC Mineral Resources
comprising:
ü Molaoi, Greece - 210,000 tonnes of zinc, 39,000 tonnes of lead and 3.5
million ounces of silver
ü Copperhead, Australia - 80,000 tonnes of copper, 9,400 tonnes of molybdenum
and 1.1 million ounces of silver
ü Plateau, Australia - 130,000 ounces of gold and 800,000 ounces of silver
"The Company will inform the market as we continue to build our resource
inventory."
Qualified Person Statement:
The technical information in this announcement is based on information
compiled by Mr Edward Fry, the Exploration Manager of Rockfire Resources plc,
who is a Member of the Australasian Institute of Mining and Metallurgy
(MAusIMM). Mr Fry has sufficient experience relevant to the style of
mineralisation and type of deposit under consideration and to the activity
which has been undertaken to qualify as a "Qualified Person" in accordance
with the AIM Rules Guidance Note for Mining and Oil & Gas Companies. Mr
Fry consents to the inclusion in the announcement of the matters based on
their information in the form and context in which it appears.
For further information on the Company, please
visit www.rockfireresources.com (http://www.rockfireresources.com/) or
contact the following:
Rockfire Resources plc: info@rockfireresources.com
David Price, Chief Executive Officer
Allenby Capital Limited (Nominated Adviser & Broker) Tel: +44 (0) 20 3328 5656
John Depasquale / George Payne (Corporate Finance)
Matt Butlin / Kelly Gardner (Sales and Corporate Broking)
Yellow Jersey PR rockfire@yellowjerseypr.com
Sarah Hollins / Henry Wilkinson Tel: +44 (0) 20 3004 9512
Mineral Resource Details and Parameters
The results of the maiden Molaoi Mineral Resource estimate are detailed in the
Statement of Mineral Resources in Table 1. The Statement of Mineral Resources
is reported in accordance with the requirements of the 2012 JORC code and is
therefore suitable for public reporting.
The Mineral Resource is reported above a cut-off grade of 4 % Zn
Rockfire Resources plc
Molaoi Mineral Resource Estimate as of 20(th) May 2022 (4% Zn cut-off)
Resource Category M t Grades Metal content
Zn EQ %* Zn % Pb % Ag g/t Zn EQ t Zn t Pb t Ag M oz
Inferred 2.3 11 9.4 1.7 47 250,000 210,000 39,000 3.5
* Zn EQ = (0.958 x Zn%) + (0.511 x Pb %) + (0.176 x Ag g/t)
This equation has factored in the historical 1984 metallurgical recoveries
into a concentrate of
95.8% Zn, 91.8 % Pb, and 91 % Ag
Assumed commodity prices (20th May 2022) are Zn $3647 USD/t, Pb $2032 USD/t,
and Ag $21.89 USD/oz
It is the company's opinion that all elements listed above have a reasonable
potential for recovery and sale
The Mineral Resource has been compiled by Edward Fry who is a full-time
employee and shareholder of Rockfire Resources and is a Member of the AusIMM.
Mr. Fry has sufficient experience that is relevant to the style of
mineralisation and type of deposit under consideration and to the activity
that he has undertaken to qualify as a Competent Person as defined in the JORC
Code.
All Mineral Resources figures reported in the table above represent estimates
at May 2022. Mineral Resource estimates are not precise calculations, being
dependent on the interpretation of limited information on the location, shape
and continuity of the occurrence and on the available sampling results. The
totals contained in the above table have been rounded to two significant
figures to reflect the relative uncertainty of the estimate. Rounding may
cause some computational discrepancies. Mineral Resources do not demonstrate
economic viability.
The Mineral Resource has been estimated in accordance with the 2012 Edition of
the 'Australasian Code for Reporting of Exploration Results, Mineral Resources
and Ore Reserves' prepared by the Joint Ore Reserves Committee of The
Australasian Institute of Mining and Metallurgy, Australian Geoscientists and
Minerals Council of Australia (The JORC Code 2012).
A detailed discussion of the Mineral Resource estimation methodology and
parameters is detailed below:
· The Mineral Resource has been calculated using historical drill hole
information. The drilling occurred between 1979 and 1988, over numerous
campaigns by the Greek Government, with a total of 173 cored drill holes. The
original drill hole assays have been validated by Rockfire through the
re-analysis of precise sampling intervals of the original drill core.
· Ordinary Kriging ("OK") was used to estimate the block grades using
Micromine software. The OK estimation utilised modelled variograms based on
flattened and realigned mineralisation sample and block positions.
· Parent block size is 2.5 m by 2.5 m by 2.5 m.
· Linear grade estimation was deemed appropriate due to the
geological/mineralisation continuity and a low Coefficient of Variation of
0.89.
· The Mineral Resource estimate has been constrained by the wireframed
mineralisation, which is a hard boundary and does not incorporate external
waste.
· The Molaoi Mineral Resource area extends over a north-south strike
length of approximately 1400 m (from 4,076,845 mN to 4,078,257 m N), has a
maximum plan width of approximately 280 m (from 665,080 mE to 665,358 mE) and
includes a 330 m vertical window between 185 m RL to -145 m RL.
· The Mineral Resource estimate is reported above a Zn cut-off grade of
4%.
· The mineral Resource is classified as 100% inferred. This is based on
data quality, sample spacing, and mineralisation continuity.
Notes to Editors
Rockfire Resources plc (LON: ROCK) is a mineral exploration company with a
portfolio of 100%-owned gold and copper projects in Queensland Australia and a
high-grade zinc deposit in Greece.
§ The Plateau deposit in Queensland has a JORC resource of 130,000 ounces of
gold and 800,000 ounces of silver.
§ The Copperhead deposit in Queensland has a JORC resource of 80,000 tonnes
of copper, 9,400 tonnes of molybdenum and 1.1 million ounces of silver.
§ The Molaoi deposit in Greece has a JORC resource of 210,000 tonnes of zinc,
39,000 tonnes of lead and 3.5 million ounces of silver.
1. JORC Code, 2012 Edition - Table 1
1.1. Section 1 Sampling Techniques and Data
Criteria JORC Code explanation Commentary
Sampling techniques · Nature and quality of sampling (eg cut channels, random chips, or · The historical drill sampling was exclusively sourced from diamond
specific specialised industry standard measurement tools appropriate to the drilled holes. The drill core sampling is assumed to be of an adequate
minerals under investigation, such as down hole gamma sondes, or handheld XRF quality.
instruments, etc). These examples should not be taken as limiting the broad
meaning of sampling. · The historical drill core was half sampled.
· Include reference to measures taken to ensure sample representivity · The mineralized zone is characterized by massive to semi-massive
and the appropriate calibration of any measurement tools or systems used. sulphides (sphalerite, galena, pyrite). This zone is surrounded by a
disseminated sulphide zone. Both of these zones are easily visible and
· Aspects of the determination of mineralisation that are Material to discernible from unmineralized host rock within the historical drill core,
the Public Report. making the determination of mineralized material fairly straight forward.
· In cases where 'industry standard' work has been done this would be · The historical diamond drill core sampling was based on geological
relatively simple (eg 'reverse circulation drilling was used to obtain 1 m intervals, with a minimum sample length of 0.1 m and a max of 2.0 m.
samples from which 3 kg was pulverised to produce a 30 g charge for fire
assay'). In other cases more explanation may be required, such as where there · The historical diamond drill core was cut in half, with half core
is coarse gold that has inherent sampling problems. Unusual commodities or sent off to analysis and the remaining half stored in appropriately marked
mineralisation types (eg submarine nodules) may warrant disclosure of detailed core trays at a secure Greek government facility.
information.
Drilling techniques · Drill type (eg core, reverse circulation, open-hole hammer, rotary · The historical drilling is composed entirely of unoriented diamond
air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or drilled core of PQ and NQ size.
standard tube, depth of diamond tails, face-sampling bit or other type,
whether core is oriented and if so, by what method, etc).
Drill sample recovery · Method of recording and assessing core and chip sample recoveries and · The historical diamond drill core recovery is recorded in a digital
results assessed. database.
· Measures taken to maximise sample recovery and ensure representative · The method of core preparation, core measurement, or sample
nature of the samples. maximization techniques were not recorded or have not been delivered by the
Greek Government to Rockfire Resources plc.
· Whether a relationship exists between sample recovery and grade and
whether sample bias may have occurred due to preferential loss/gain of · No correlation exists between sample recovery and sample grade.
fine/coarse material.
Logging · Whether core and chip samples have been geologically and · Historical geological logs for a portion of the drill holes have been
geotechnically logged to a level of detail to support appropriate Mineral found and translated from Greek. They are of sufficient detail to support a
Resource estimation, mining studies and metallurgical studies. Mineral Resource estimation.
· Whether logging is qualitative or quantitative in nature. Core (or · The core logging is considered qualitative in nature.
costean, channel, etc) photography.
· Only a portion of the logs have been provided to Rockfire from the
· The total length and percentage of the relevant intersections logged. Greek Government. These logs represent ~30 % of the relevant drill holes,
being 2760.9 m of the 9447.2 drill meters. The geological logs demonstrate
good relationship between the sulphide rich zones and the historical drill
assays.
Sub-sampling techniques and sample preparation · If core, whether cut or sawn and whether quarter, half or all core · The core was cut and ½ core was sent for analysis. The core in
taken. places have been further samples with the remaining material stored in well
labelled plastic bags within the core trays.
· If non-core, whether riffled, tube sampled, rotary split, etc and
whether sampled wet or dry. · No information exists regarding the nature, quality, or
appropriateness of the historical sampling method beyond what can be inferred
· For all sample types, the nature, quality and appropriateness of the from the remaining core which has been located by Rockfire Resources.
sample preparation technique.
· No information exists regarding the quality control procedures.
· Quality control procedures adopted for all sub-sampling stages to
maximise representivity of samples. · No information exists regarding the quality assurance procedures
· Measures taken to ensure that the sampling is representative of the · The sample sizes are appropriate given the
in situ material collected, including for instance results for field massive/semi-massive/disseminated sulphide nature of the mineralization.
duplicate/second-half sampling.
· Whether sample sizes are appropriate to the grain size of the
material being sampled.
Quality of assay data and laboratory tests · The nature, quality and appropriateness of the assaying and · The assaying was completed by an Italian government laboratory (ITMI)
laboratory procedures used and whether the technique is considered partial or based in Rome, no comment can be made regarding the appropriateness of the
total. assaying method beyond what can be inferred from the resampling program which
found a good correlation between the historical and resampled Zn assays. The
· For geophysical tools, spectrometers, handheld XRF instruments, etc, resampling demonstrated a precision of approx. 10%. As such the historical
the parameters used in determining the analysis including instrument make and data is considered as being appropriate for use in this Mineral Resource
model, reading times, calibrations factors applied and their derivation, etc. Estimate.
· Nature of quality control procedures adopted (eg standards, blanks, · No records exist regarding the assay method used or the quality
duplicates, external laboratory checks) and whether acceptable levels of assurance/quality control procedures enacted.
accuracy (ie lack of bias) and precision have been established.
Verification of sampling and assaying · The verification of significant intersections by either independent · The historic drill results have been verified by Rockfire personnel.
or alternative company personnel. The historical drill core was located at a government facility in Athens and
select intervals were resampled and sent to ALS for verification analysis.
· The use of twinned holes.
· No twinned holes have been drilled by Rockfire at this stage.
· Documentation of primary data, data entry procedures, data
verification, data storage (physical and electronic) protocols. · The original hard copy databases were scanned and presented to
Rockfire resources. These databases were then digitized and validated by
· Discuss any adjustment to assay data. Rockfire personnel. All drill data is stored in a Micromine based system.
Manual backups are completed to both separate hard-drive and cloud based
services.
· No adjustment to assay data was completed.
Location of data points · Accuracy and quality of surveys used to locate drill holes (collar · The accuracy of the drill hole database is unable to be determined at
and down-hole surveys), trenches, mine workings and other locations used in this point. The data has been translated from local grid system into UTM
Mineral Resource estimation. WGS84. The drill data has been matched with difference sources of data to
provide the best location fit. This fit corresponds well with the surveyed
· Specification of the grid system used. underground development completed by the Greek Government.
· Quality and adequacy of topographic control. · UTM WGS 84
· The topographic control has been extracted from Google Earth. This is
considered adequate for the Mineral Resource Estimate classification applied.
Data spacing and distribution · Data spacing for reporting of Exploration Results. · Drill hole spacing was typically completed on a 50m along strike and
50 m down dip basis.
· Whether the data spacing and distribution is sufficient to establish
the degree of geological and grade continuity appropriate for the Mineral · The drill hole spacing is sufficient to establish the geological and
Resource and Ore Reserve estimation procedure(s) and classifications applied. grade continuity for the Mineral Resource Estimate classification.
· Whether sample compositing has been applied. · Samples were composited to 1 m lengths prior to estimation.
Orientation of data in relation to geological structure · Whether the orientation of sampling achieves unbiased sampling of · Drill orientations were designed to intersect any geological contacts
possible structures and the extent to which this is known, considering the or mineralized zones at a high angle. Typical drilling is vertical or inclined
deposit type. to the west. The historical drilling was completed by the Greek Government,
which reduces the inclination to cluster drilling around high grade areas. As
· If the relationship between the drilling orientation and the such, the drilling is well spaced and the sampling is considered as being
orientation of key mineralised structures is considered to have introduced a unbiased.
sampling bias, this should be assessed and reported if material.
Sample security · The measures taken to ensure sample security. · No information exists regarding the nature, quality, or
appropriateness of the historical sample security.
Audits or reviews · The results of any audits or reviews of sampling techniques and data. · No information exists regarding the nature, quality, or
appropriateness of the historical sampling reviews.
1.2.
1.3. Section 2 Reporting of Exploration Results
(Criteria listed in the preceding section also apply to this section.)
Criteria JORC Code explanation Commentary
Mineral tenement and land tenure status · Type, reference name/number, location and ownership including · The Mineral Resource Estimation is for the Molaoi Deposit located in
agreements or material issues with third parties such as joint ventures, the Laconia Municipality in Greece. Molaoi is covered by the exploration and
partnerships, overriding royalties, native title interests, historical sites, mining lease 'M1 (Molaoi Apidia).
wilderness or national park and environmental settings.
· Rockfire Resources plc owns 100 % of the Project through its
· The security of the tenure held at the time of reporting along with subsidiary Hellenic Minerals IKE.
any known impediments to obtaining a licence to operate in the area.
Exploration done by other parties · Acknowledgment and appraisal of exploration by other parties. · The historical exploration work was completed by the Greek Government
geological department "IGME", towards the end of the exploration phase a joint
venture with a company called "METBA" was established. IGME completed the
generative exploration work (e.g., stream sediment sampling, soil sampling,
drilling, metallurgy, underground drive development, resource estimations).
METBA completed high level technical studies and feasibility studies.
Geology · Deposit type, geological setting and style of mineralisation. · The Molaoi deposit was initially considered as being a zinc dominant
'Kuroko style" Volcanogenic Massive sulphide (VMS) system. Debate as to the
validity of the VMS model is ongoing. There is a significant body of evidence
which suggests that these Zinc VMS deposits are actually structurally
controlled hydrothermal systems (possibly intrusion related). The geological
and structural studies indicate a complex setting of andesite lavas and tuffs
along with clay-carbonate sediments and numerous fault breccias which have
undergone at least three folding events. At least one folding event is noted
as being isoclinal. Given the structural complexity and the relatively good
level of continuation (+1400 m long) of the zinc mineralized zones it is
unlikely that the mineralization is primary in nature, as suggested by the VMS
model. As such, the hydrothermally derived model (possibly intrusion related)
is adopted. The mineralized zones are typically hosted in fault breccias and
are represented by massive/semi-massive sulphides surrounded by zones of
disseminated sulphides. The sulphides consist of sphalerite, galena, and
pyrite. The primary elements of interest are Zn, Pb, Ag, and Ge. Low levels of
cadmium have been recorded within the deposit, it is unclear as whether or not
Cd is a credit or a detriment to the mineralization at this stage.
Drill hole Information · A summary of all information material to the understanding of the · Exploration results are not being reported.
exploration results including a tabulation of the following information for
all Material drill holes: · All appropriate information has been included within the appendices.
No drill hole information has been excluded.
o easting and northing of the drill hole collar
· There are a small number of historical drill holes that do not
o elevation or RL (Reduced Level - elevation above sea level in metres) of the contain any assay data. Additionally, there are historical drill holes which
drill hole collar have been displayed in late-stage cross section which have not been detailed
in the database provided by the Greek Government to Rockfire Resources plc.
o dip and azimuth of the hole Some of the drill holes that do not contain assay data are proximal to drill
holes that do contain assay data. As such these holes have been ignored for
o down hole length and interception depth the Mineral Resource Estimation.
o hole length.
· If the exclusion of this information is justified on the basis that
the information is not Material and this exclusion does not detract from the
understanding of the report, the Competent Person should clearly explain why
this is the case.
Data aggregation methods · In reporting Exploration Results, weighting averaging techniques, · Exploration results are not being reported.
maximum and/or minimum grade truncations (eg cutting of high grades) and
cut-off grades are usually Material and should be stated. · N/A, as a Mineral Resource Estimate is being reported.
· Where aggregate intercepts incorporate short lengths of high grade · The individual grades are estimated, from this a zinc equivalent has
results and longer lengths of low grade results, the procedure used for such been calculated. The assumptions used are;
aggregation should be stated and some typical examples of such aggregations
should be shown in detail. Ø Zinc price $ 3647 USD/t, Lead price $2032 USD/t, Silver price 21.89 USD/oz
(dated 16(th) May 2022
· The assumptions used for any reporting of metal equivalent values
should be clearly stated. Ø Historical flotation metallurgical test work show significant recoveries
into a concentrate. The recoveries into the concentrate are 95.8 % for Zn,
91.8 % for Pb, and 91 % for Ag.
Ø It is the company's opinion that all the elements included in the metal
equivalent have a reasonable potential to be recovered and sold.
Relationship between mineralisation widths and intercept lengths · These relationships are particularly important in the reporting of · The drill lines and drill hole orientations have been orientated to
Exploration Results. intercept the mineralization as close to 90 degrees as possible.
· If the geometry of the mineralisation with respect to the drill hole · The drill holes have been orientated either vertical or due west. The
angle is known, its nature should be reported. deposit strikes due north and generally dips 40-60 degrees to the east.
· If it is not known and only the down hole lengths are reported, there
should be a clear statement to this effect (eg 'down hole length, true width
not known').
Diagrams · Appropriate maps and sections (with scales) and tabulations of · Relevant diagrams have been included within the Mineral Resource
intercepts should be included for any significant discovery being reported Estimate report main body.
These should include, but not be limited to a plan view of drill hole collar
locations and appropriate sectional views.
Balanced reporting · Where comprehensive reporting of all Exploration Results is not · N/A as a Mineral Resource Estimate is being reported.
practicable, representative reporting of both low and high grades and/or
widths should be practiced to avoid misleading reporting of Exploration
Results.
Other substantive exploration data · Other exploration data, if meaningful and material, should be · Results were estimated from drill hole assay data, with geological
reported including (but not limited to): geological observations; geophysical logging used to guide the interpretation.
survey results; geochemical survey results; bulk samples - size and method of
treatment; metallurgical test results; bulk density, groundwater, geotechnical · Historical metallurgical test work has been completed at the Molaoi
and rock characteristics; potential deleterious or contaminating substances. deposit, further details are located in Section 3.
· Bulk Density calculates have been completed by Rockfire Resources
plc, further explanation is detailed in Section 3.
Further work · The nature and scale of planned further work (eg tests for lateral · Follow up diamond drilling planned, which will be designed to twin
extensions or depth extensions or large-scale step-out drilling). historical holes and to extend/infill the resource area.
· Diagrams clearly highlighting the areas of possible extensions, · Additional metallurgical test work may be undertaken on the fresh
including the main geological interpretations and future drilling areas, drill samples.
provided this information is not commercially sensitive.
· Additional bulk density calculations of the mineralized zone and the
waste rock will be completed.
1.4. Section 3 Estimation and Reporting of Mineral Resources
(Criteria listed in section 1, and where relevant in section 2, also apply to
this section.)
Criteria JORC Code explanation Commentary
Database integrity · Measures taken to ensure that data has not been corrupted by, for · No information exists regarding the nature, quality, or
example, transcription or keying errors, between its initial collection and appropriateness of the historical data validation.
its use for Mineral Resource estimation purposes.
· Rockfire performed initial drill audits in Micromine. Rockfire
· Data validation procedures used. checked collar coordinates, hole depths, hole orientation, assay data overlaps
and duplicate data. Errors were found in the collar file which were documented
and amended.
· There are a small number of historical drill holes that do not
contain any assay data. Additionally, there are historical drill holes which
have been displayed in late stage cross section which have not been detailed
in the database provided by the Greek Government to Rockfire Resources plc.
Some of the drill holes that do not contain assay data are proximal to drill
holes that do contain assay data. As such these holes have been ignored for
the Mineral Resource Estimation.
· There are assay values in the digital database which are represented
by a -1 value. Some of these assay results were resampled and analysed by
Rockfire at ALS. The -1 values were found to contain above detection results
(e.g., -1 original assay result for Cd returning 988 ppm Cd during the
resampling). This implies that the -1 values represent unassayed values as
opposed to below detection assays.
Site visits · Comment on any site visits undertaken by the Competent Person and the · No site visit was completed by the Competent Person as he fell ill
outcome of those visits. with COVID 19 and was unable to leave Australia for the organised site visit.
Other Rockfire personnel have visited sit and have noted the presence of
· If no site visits have been undertaken indicate why this is the case. historical small scale mining pits, gossanous material at surface, and have
located the cement sealed exploration decline.
Geological interpretation · Confidence in (or conversely, the uncertainty of) the geological · There is a relatively high degree of geological uncertainty with the
interpretation of the mineral deposit. geological model at this stage. This is because there have only been approx.
30% of the logs provided by the Greek Government to Rockfire Resources.
· Nature of the data used and of any assumptions made. Regardless of this, the geological logging has clearly shown that mineralized
zones are located within sulphide rich fault zones. At the main section of the
· The effect, if any, of alternative interpretations on Mineral deposit, the mineralization exists as three parallel zones. The main zone has
Resource estimation. been modelled in this Mineral Resource and correlates well with the current
geology and the historical 1985 modelling of the mineralisation. This provides
· The use of geology in guiding and controlling Mineral Resource a proxy validation of the geological interpretation and mineralization model.
estimation.
· The geological logs and drill hole assays have been used to model the
· The factors affecting continuity both of grade and geology. mineralisation. The assumptions made are that both the assay values and
geological logs are reliable and sufficient.
· The effect of alternative interpretations will modify the Mineral
Resource significantly. As only one of the three repetitions has been modelled
in this Resource Estimation, if a model were to cherry pick the high-grade
mineralisation zones from each layer into a single layer, then this would
significantly increase the grade and size of the single layer of
mineralization. To avoid this issue, the spatial continuation of each layer
has been preserved, i.e., the model has avoided abrupt of significant changes
in orientation which would favour a higher-grade higher-tonnage
interpretation.
· Where the geological logs were noted, they were used to model the
mineralization. From these points, the mineralisation model was extended
section by section to identify the most likely points continuation of the
mineralization.
· The largest factors impacting mineralisation continuation are
structural in nature. The modelling has identified numerous faults, these
faults were noted or mapped at surface and have been used to explain grade
domains (abrupt changes in the orientation of planar mineralisation).
Additionally, interference folding has been identified within the
mineralization model.
Dimensions · The extent and variability of the Mineral Resource expressed as · The Molaoi Mineral Resource area extends over a north south strike
length (along strike or otherwise), plan width, and depth below surface to the length of ~1400 m (from 4,076,845 mN to 4,078,257 m N) has a maximum plan
upper and lower limits of the Mineral Resource. width of ~280 m (from 665,080 mE to 665,358 mE) and includes the ~330 m
vertical window from (185 m RL to -145 m RL)
Estimation and modelling techniques · The nature and appropriateness of the estimation technique(s) applied · Ordinary Kriging (OK) was used as the estimation method. The OK
and key assumptions, including treatment of extreme grade values, domaining, estimation utilized variograms for Zn, Pb, and Ag. Given the narrow vein
interpolation parameters and maximum distance of extrapolation from data nature of the deposit an arbitrary 2 m was allocated to the variogram Axis 3
points. If a computer assisted estimation method was chosen include a for each element. The estimation was run using Micromine software in three
description of computer software and parameters used. passes. Linear grade estimation was deemed appropriate due to the low
coefficient of variation for the Zinc (CoV 0.89). Maximum extrapolation of
· The availability of check estimates, previous estimates and/or mine wireframes was 50 m beyond the last drill intersect along strike and down dip.
production records and whether the Mineral Resource estimate takes appropriate This is approximately equal to the drill hole spacing. Extreme grade values
account of such data. were truncated. The truncation points were based on reviewing the statistical
distribution (histogram, probability plot, cumulative frequency curve) of the
· The assumptions made regarding recovery of by-products. modelled grade values to find the most logical top cut value. Comparisons
between a zone-by-zone estimation and an all-in flattened model were made.
· Estimation of deleterious elements or other non-grade variables of Given that the mineralisation is most likely a single mineralised fault zone
economic significance (eg sulphur for acid mine drainage characterisation). that has subsequently undergone multiple phases of folding and faulting, the
flattened model estimation technique was applied. This then allowed the
· In the case of block model interpolation, the block size in relation incorporation of all the relevant data points for the Resource Estimation as
to the average sample spacing and the search employed. opposed to being limited to the data points within the zoned area. The
resulting model visually looks more appropriate and is considered as being a
· Any assumptions behind modelling of selective mining units. more accurate estimation. Evaluation of the two OK models revealed no
significant difference in the global Mineral Resource Estimate. As such, the
· Any assumptions about correlation between variables. flattened estimation model was utilized.
· Description of how the geological interpretation was used to control · A historical Non-JORC Mineral Resource Estimate was completed by The
the resource estimates. Greek Government.
· Discussion of basis for using or not using grade cutting or capping. · No assumption regarding deleterious elements have been made.
· The process of validation, the checking process used, the comparison · A single concentrate containing zinc, lead, and silver is considered
of model data to drill hole data, and use of reconciliation data if available. at this stage. Additional work is required to quantify the levels of cadmium
and germanium within the concentrate.
· The parent block size is 2.5 m N/S/Z this is in relation to a 50 m
drill spacing. The blocks have not been rotated due to the requirement of
flattening the zones for grade interpretation. This is also the reason for the
relatively small parent block size.
· No assumption regarding the SMU have been made. It is worth noting
that a review of peer zinc SMUs indicate that a 2.5 m N/S/Z size is
sufficient.
· Zinc and lead have a moderate correlation, zinc and silver have a
strong correlation, and silver and lead have a strong correlation.
· The deposit mineralization was constrained by wireframe solids
constructed using a nominal 2% Zn+Pb+Ag cut-off grade with a minimum downhole
length of 1 m. The wireframes were applied as hard boundaries.
· Statistical analyses were carried out on data from the four modelled
zones. Top cuts were determined by reviewing the statistical distribution
(histogram, probability plot, cumulative frequency curve) of the modelled
grade values. Zinc grades within the model were cut to 36.26 % (3 data points
removed, 1.6 %), lead values were cut to 7.19 % (1 data point 0.53 %), and
silver values were cut to 136.08 g/t (6 data points, 3.2 %).
· Validation of the model was completed by comparing the model to an
IDW model and the grade tonnage average of the wireframe sets.
Moisture · Whether the tonnages are estimated on a dry basis or with natural · Tonnages and grades were estimated on a dry in-situ basis.
moisture, and the method of determination of the moisture content.
Cut-off parameters · The basis of the adopted cut-off grade(s) or quality parameters · The Mineral Resource Estimate has been constrained by the wireframed
applied. mineralization envelope and is undiluted by external waste. The Estimate is
reported using a cut-off grade of 4 % Zinc. This was based on a review of peer
Zinc deposit Mineral Resource Estimates.
Mining factors or assumptions · Assumptions made regarding possible mining methods, minimum mining · Underground mining with concentration via flotation and transporting
dimensions and internal (or, if applicable, external) mining dilution. It is the concentrate for out of country processing is envisioned by the company. As
always necessary as part of the process of determining reasonable prospects no dilution is incorporated into the model a relatively high cut-off grade of
for eventual economic extraction to consider potential mining methods, but the 6% was used to buffer the effects of possible dilution. To discuss possible
assumptions made regarding mining methods and parameters when estimating mining methods at this stage is premature. Many factors need to be considered
Mineral Resources may not always be rigorous. Where this is the case, this when proposing mining methods, these factors include but are not limited to
should be reported with an explanation of the basis of the mining assumptions the following: -
made.
Ø Mineralisation continuity,
Ø Level of mineralisation orientation change,
Ø Mineralisation dip (dip angle > than angle of repose),
Ø Mineralisation competency,
Ø Mineralisation thickness,
Ø Wall rock competency,
Ø Mechanisation type, &
Ø Environmental and social limitations.
The mineralisation displays good continuity with a large level of orientation
change (anastomosing, faulted, and folded). This requires a mining method that
can adjust swiftly to changes in orientation. The mineralisation dip is
between 45 and 70 degrees. The Wall rock competency and the angle of repose is
unknown and could provide problems with stoping mining methods. The Cut and
Fill mining method may be possible depending on favourable results in the
above mentioned unknow parameters.
Metallurgical factors or assumptions · The basis for assumptions or predictions regarding metallurgical · Historical metallurgical test work has indicated significant
amenability. It is always necessary as part of the process of determining recoveries of the sulphides into a concentrate. The recovery values are 95.8 %
reasonable prospects for eventual economic extraction to consider potential for Zn, 91.8 % for Pb, and 91 % for Ag. Historical metallurgical test work of
metallurgical methods, but the assumptions regarding metallurgical treatment the oxide/transition material shows varying and inconclusive results. As such
processes and parameters made when reporting Mineral Resources may not always only the fresh sulphide ore has been incorporated within the Mineral Resource
be rigorous. Where this is the case, this should be reported with an Estimate.
explanation of the basis of the metallurgical assumptions made.
Environmen-tal factors or assumptions · Assumptions made regarding possible waste and process residue · To discuss detailed environmental factors or assumptions at this
disposal options. It is always necessary as part of the process of determining stage is premature. An entirely underground operation where it is possible to
reasonable prospects for eventual economic extraction to consider the place waste rock as back fill into the stope is conceivable. The ore can be
potential environmental impacts of the mining and processing operation. While concentrated using the flotation method and could be process out of country at
at this stage the determination of potential environmental impacts, existing facilities. No open pit mining is proposed and this is reflects by
particularly for a greenfields project, may not always be well advanced, the the top 40m (from surface) being excluded from the Mineral Resource Estimate.
status of early consideration of these potential environmental impacts should
be reported. Where these aspects have not been considered this should be
reported with an explanation of the environmental assumptions made.
Bulk density · Whether assumed or determined. If assumed, the basis for the · Bulk Density measurements where completed on the resampled drill core
assumptions. If determined, the method used, whether wet or dry, the frequency by ALS laboratories by using the water immersion technique. When evaluated,
of the measurements, the nature, size and representativeness of the samples. the data indicated a relationship between the sample weight and Bulk Density
result up to ~700 g. As such all data under 700 g was discounted. The interval
· The bulk density for bulk material must have been measured by methods weighted average of the Bulk Density calculations for the samples greater than
that adequately account for void spaces (vugs, porosity, etc), moisture and 700 g is 2.95.
differences between rock and alteration zones within the deposit.
· The data above 700 g was then plotted against the zinc values, this
· Discuss assumptions for bulk density estimates used in the evaluation highlighted several anomalous samples which were removed from the input data.
process of the different materials. Post cleaning, the correlation coefficient was very strong (0.92) with an R(2)
(shared variance) of 0.842 (84.2%). As density is predicted to be dynamic
throughout the deposit, the equation Y = 0.284x + 2.5481 was used to populate
the block Bulk Density data, as opposed to a single 2.95 SG value for the
entire fresh rock deposit.
Classification · The basis for the classification of the Mineral Resources into · The Mineral Resource Estimate reported here is in compliance with the
varying confidence categories. 2012 Edition of the 'Australasian Code for Reporting of Exploration Results,
Mineral Resources, and Ore Reserves' by the Joint Ore Reserves Committee
· Whether appropriate account has been taken of all relevant factors (JORC). The Mineral Resource is classified as 100% Inferred based on the
(ie relative confidence in tonnage/grade estimations, reliability of input missing data, uncertain quality controls of the data, the sample spacing, and
data, confidence in continuity of geology and metal values, quality, quantity mineralization continuity.
and distribution of the data).
· The input data is comprehensive in its coverage of the mineralization
· Whether the result appropriately reflects the Competent Person's view and does not favour or misrepresent the in-situ mineralization. A moderate
of the deposit. level of geological confidence exists. Acquiring the missing geological logs
is an important recommendation.
· The Mineral Resource Estimate appropriately reflects the view of the
Competent Person.
Audits or reviews · The results of any audits or reviews of Mineral Resource estimates. · Internal review of the Mineral Resource Estimate has been completed
by Rockfire Resources plc. This review consisted of running through each step
of the Resource Estimation process with the Rockfire CEO and visually
inspecting the final product.
Discussion of relative accuracy/ confidence · Where appropriate a statement of the relative accuracy and confidence · The mineralization geometry and continuity has been adequately
level in the Mineral Resource estimate using an approach or procedure deemed interpreted to reflect the applied classification of inferred Mineral
appropriate by the Competent Person. For example, the application of Resource. The data quality is sufficient to support the interpretation. The
statistical or geostatistical procedures to quantify the relative accuracy of use of an Italian government laboratory (ITMI) for the historical results have
the resource within stated confidence limits, or, if such an approach is not been validated by the resampling completed by Rockfire Resources who utilized
deemed appropriate, a qualitative discussion of the factors that could affect Australian Laboratory Services (ALS). ALS generated reasonably similar Zn
the relative accuracy and confidence of the estimate. results with a precision of ~10%. Finding the missing historical drill hole
logs is a priority for Rockfire and will help improve the confidence in the
· The statement should specify whether it relates to global or local Mineral Resource Estimate.
estimates, and, if local, state the relevant tonnages, which should be
relevant to technical and economic evaluation. Documentation should include · The Mineral Resource statement relates to the global estimate of
assumptions made and the procedures used. tonnes and grade for the fresh rock component only.
· These statements of relative accuracy and confidence of the estimate · No production data exists for the project.
should be compared with production data, where available.
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