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| Share Name | Share Symbol | Market | Type | Share ISIN | Share Description |
|---|---|---|---|---|---|
| Red Rock Resources Plc | LSE:RRR | London | Ordinary Share | GB00BYWKBV38 | ORD 0.01P |
| Price Change | % Change | Share Price | Bid Price | Offer Price | High Price | Low Price | Open Price | Shares Traded | Last Trade | |
|---|---|---|---|---|---|---|---|---|---|---|
| 0.00 | 0.00% | 0.0575 | 0.055 | 0.06 | 0.0575 | 0.0575 | 0.0575 | 8,339,121 | 08:00:00 |
| Industry Sector | Turnover | Profit | EPS - Basic | PE Ratio | Market Cap |
|---|---|---|---|---|---|
| Iron Ores | 0 | -2.67M | -0.0011 | -0.55 | 1.49M |
From Apr 2019 to Apr 2024
TIDMRRR
RNS Number : 0738Q
Red Rock Resources plc
23 February 2021
Red Rock Resources PLC
Mineral Resource Update
at the Mikei Gold Project, Kenya (JORC, 2012)
Mineral Resource of 723 koz at 1.49 g/t Reported
22 February 2021
Red Rock Resources Plc ("Red Rock" or "the Company"), the natural resource development company with interests in gold, copper/cobalt, manganese and minerals, announces the completion of a Mineral Resource estimate ("MRE") updated to comply with the 2012 edition of the Code published by the Australasian Joint Ore Reserves Committee ("JORC") over parts of Red Rock's exploration license at Mikei, Migori, Kenya comprising the Mikei Gold Project ("MGP"). The supporting documentation (the "Report") was prepared by CSA Global (UK) Limited ("CSA Global").
The Report documents the results of Mineral Resource estimation work initially conducted in 2011 and 2012 and revised in 2021 in order to report the Mineral Resource according to JORC (2012) guidelines. MGP was assessed for reasonable prospects for eventual economic extraction (RPEEE) by applying conceptual benchmarked costs to calculate conceptual reporting pit shells. Any material outside or below the reporting pit shell was updated as "Not Classified" since it did not meet the criteria to be reported as a Mineral Resource.
The total Mineral Resource, for both Inferred and Indicated categories at a 0.5 g/t Au cut-off, is estimated at:
15.13 Mt @ 1.49 g/t Au with contained metal content of 723 koz Au
Key Points
-- MRE covered the five prospect areas covered by the 2012 MRE
-- Application of RPEEE principles required by JORC (2012) led to the exclusion of some previously estimated Mineral Resource areas and a consequent 39% reduction in reported ounces of gold
-- Gold grade of the MRE for the same reason increased by 18% to 1.49 g/t
-- Some material previously stated as Indicated in the oxidised zone has been downgraded to Inferred, reflecting uncertainties relating to the terrain model and the extent of artisanal activity since 2012
-- Detailed recommendations for a first stage step-out drilling programme made to potentially increase the size of the MRE
Red Rock Chairman Andrew Bell comments: "We are delighted to announce an updated Mineral Resource at Mikei, with a higher gold grade. These conceptual pit shells used to test for reasonable prospects of extraction will now act as a springboard for our future exploration which will be focused on Resource enhancement.
After having been for several years prevented from carrying out work on the property while other nearby projects in Tanzania and Kenya progressed, the first necessary steps on our return were to conduct updated baseline and Resource studies, and to prepare an immediate programme to upgrade and extend our Mineral Resource.
Updating our Mineral Resource Estimate to JORC (2012) was essential if we were to make public reference to it, and the exercise of complying with it has been invaluable in two ways.
First, the application of conceptual benchmarked costs to calculate conceptual reporting pit shells ensures that the reported Mineral Resource is aligned with a modern, industry-recognised method of testing for reasonable prospects for eventual economic extraction. This together with the higher grade within the conceptual pit shells enables us to report a Mineral Resource that looks more robust in the context of current gold prices.
Secondly, the exercise of working out what, on the assumptions made, lay outside the pit shell but nearby or along strike showed us where targeted step-out drilling might prove effective in extending the pit, and so gave us our first 14, and mainly shallow, new drill hole locations. These we can test without delay while planning further programmes for infill and step-out drilling and for testing mineralisation at depth.
We now have the opportunity to build on this solid base and it is our belief that the potential for expansion at and around Mikei is strong".
Background
The MGP comprises two prospecting licences which cover approximately 245 km(2) , namely PL/2018/0202 and PL/2018/0203, over the Migori Greenstone Belt, and are located along the northern margin of the Tanzanian Craton. The licences extend 63 km along strike of the belt, which also hosts the Kilimapesa Gold Mine. The North Mara Gold Mine, which is operated by Barrick Gold, is located 30 km to the south of the MGP in Tanzania.
Regional exploration in the project area began in the early 1930s and culminated in the identification and subsequent mining of the Macalder volcanogenic massive sulphide (VMS) base metal mine.
In 2010, Red Rock began the extensive task of file organisation, data digitisation and compilation of available historical data, following which CSA Global performed cross-checks and validation steps prior to loading it into a Structured Query Language (SQL) database using Datashed. During 2011 and 2012, Red Rock undertook an infill drilling programme at all five of the lode gold prospects; MK, Kakula-Kalange-Munyu (KKM), Kakula-Kalange-Munyu West (KW), Nyanza (NZ), and Gori Maria (GM) within PL/2018/0202.
http://www.rns-pdf.londonstockexchange.com/rns/0738Q_1-2021-2-23.pdf [Figure 1: Total field aeromagnetic imagery for the Mikei area collected by Red Rock, with drill collars annotated in yellow and surface structural dip and dip-directions as red triangles]
The Report documents the results of Mineral Resource estimation work initially conducted in 2011 and 2012 and revised in 2021 in order to report the Mineral Resources according to JORC (2012) guidelines. No new data is available since the 2012 report, and as such, those estimates remain valid and disclosure to JORC (2012) is the focus of the Report.
Mineral Resource Estimate and Comparison with Previous Estimate
The Mineral Resource has been estimated using geological models developed by Red Rock and CSA Global. The MRE has been undertaken using ordinary kriging (OK) on volume block models for all prospects. Consideration of natural grade populations, along with top cutting, compositing and variography has been completed for all prospects. This has produced robust 3D grade models for each prospect, that can be used for conceptual mine planning studies and further exploration planning.
The MRE is reported in accordance with JORC (2012) guidelines, following the application of reasonable prospects of eventual economic extraction by means of pit shells supported by conceptual cost and gold price forecast parameters. The Mineral Resource is reported at a cut-off of 0.5 g/t Au.
The JORC Code (2012) defines a Mineral Resource as 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. The location, quantity, grade (or quality), continuity and other geological characteristics of a Mineral Resource are known, estimated, or interpreted from specific geological evidence and knowledge, including sampling. Mineral Resources are subdivided, in order of increasing geological confidence, into Inferred, Indicated and Measured categories.
The Mineral Resource estimate for all MGP prospects is reported according to the JORC (2012) guidelines. The geology for each prospect is broadly understood. Sectional interpretations were undertaken using geological information, structural measurements, and grade relationships. The statistical grade characteristics of the individual prospects are generally well understood, and a reasonable amount of density determinations were conducted to ensure an acceptable level of confidence in the bulk density of the material being reported as Mineral Resources.
Prior to Mineral Resource classification, a review of all historical and modern supporting data was undertaken. CSA Global concluded that there is adequate confidence in both the historical and Red Rock data to classify areas of the Mineral Resource as either Indicated or Inferred. Classification was further reviewed on a prospect-by-prospect basis, following consideration of data quality, data spacing, continuity of mineralised domains, and confidence in the grade estimate.
Where appropriate, a coherent zone of mineralisation, located around the more densely sampled core, was assigned an Indicated classification. The extremities of each block model, that were supported by fewer data and were therefore less reliably informed, were classified as Inferred.
All prospects, except GM, were classified as Indicated and Inferred Mineral Resources. GM was classified as Inferred only, mainly due to the relatively low average RC drill recovery of 62%.
Due to the uncertain lateral extent and depth of artisanal mining at the Mikei prospects, and the lack of topographic data to accurately deplete the Mineral Resource, all oxidised material was classified as Inferred Mineral Resources.
The term "reasonable prospects for eventual economic extraction" (RPEEE) implies a realistic inventory of mineralisation which, under assumed and justifiable technical, economic and development conditions, might, in whole or in part, become economically extractable. The assumption is that the Mikei prospects will be extracted by open pit mining. The MGP block models were assessed for RPEEE by applying conceptual benchmarked costs to calculate reporting pit shells. The following conceptual parameters were applied for open pit mining:
-- Mining cost: US$3/tonne -- Processing cost: US$22/tonne ore -- Pit slope angle: 52deg -- Recovery: 90% -- Royalty: 7% -- Gold price: US$ 1,800/troy ounce.
The Mineral Resource is reported as that material within the RPEEE pit shells, and above a cut-off grade of 0.5 g/t Au. The Mineral Resource is reported as of 18 January 2021 (Table 1).
Table 1: Mineral Resource for the Mikei prospects reported at a cut-off of 0.5 g/t Au, as of 18 January 2021
Hot Features
Premium
Area Indicated Inferred Total
-------------------------- -------------------------- --------------------------
Tonnage Grade Content Tonnage Grade Content Tonnage Grade Content
(Mt) (g/t (koz (Mt) (g/t (koz (Mt) (g/t (koz
Au) Au) Au) Au) Au) Au)
-------- ------ -------- -------- ------ -------- -------- ------ --------
KKM 7.88 1.10 277.8 2.63 1.11 93.5 10.51 1.10 371.3
KW 0.61 1.10 21.6 0.32 1.42 14.7 0.93 1.21 36.3
NZ 1.04 3.96 132.0 0.32 3.17 32.2 1.35 3.78 164.1
GM - - - 1.91 1.37 84.0 1.91 1.37 84.0
MK 0.28 5.48 49.0 0.15 3.83 18.2 0.43 4.91 67.1
------- -------- ------ -------- -------- ------ -------- -------- ------ --------
Total 9.81 1.52 480.4 5.32 1.42 242.6 15.13 1.49 723.0
------- -------- ------ -------- -------- ------ -------- -------- ------ --------
Note:
-- Computational errors may exist due to rounding.
For comparison, there follows the MRE reported in 2012 (Table 2):
Table 2: Mineral Resource for the Mikei prospects reported at a cut-off of 0.5 g/t Au, as of December 2012
Area Indicated Inferred Total
-------------------------- -------------------------- --------------------------
Tonnage Grade Content Tonnage Grade Content Tonnage Grade Content
(Mt) (g/t (koz (Mt) (g/t (koz (Mt) (g/t (koz
Au) Au) Au) Au) Au) Au)
-------- ------ -------- -------- ------ -------- -------- ------ --------
KKM 16.34 1.00 525.3 1.41 1.15 52.1 17.75 1.01 577.5
KW 1.13 1.07 38.9 3.03 1.02 99.4 4.16 1.04 138.2
NZ 1.17 3.73 140.3 1.15 1.70 62.9 2.32 2.72 203.2
GM - - - 3.78 1.16 141.0 3.78 1.16 141.0
MK 0.77 4.05 100.3 0.58 1.76 32.8 1.35 3.07 133.1
------- -------- ------ -------- -------- ------ -------- -------- ------ --------
Total 19.41 1.29 805.0 9.95 1.21 387.1 29.36 1.26 1,192.1
------- -------- ------ -------- -------- ------ -------- -------- ------ --------
The 2021 Mineral Resource utilised the same block models that were used to report the 2012 Mineral Resource. No additional exploration data have been collected at the project since reporting the Mineral Resource in 2012, therefore the grade and density estimates are still valid as they are representative of the available data. Two criteria have been updated to report the 2021 Mineral Resource:
1) Artisanal mining has continued at the Migori prospects since the 2012 Mineral Resource. A detailed topographic survey was not available, such that the block models could be depleted by the mining. Without more detailed information, the assumption is that all artisanal mining has taken place in the oxidised zone. For the 2021 Mineral Resource, all oxidised material that was previously classified as Indicated in 2012, has been downgraded to Inferred. This downgrade represents an 85% decrease in Indicated oxide tonnage, and an 83% decrease in Indicated oxide gold content, to the Inferred category.
2) An industry recognised test for RPEEE was applied to the block models to report the 2021 Mineral Resource. The assumption is that Mineral Resources at the Migori prospects will be extracted by open pit mining. Conceptual mining costs were applied to calculate RPEEE pit shells in which the Mineral Resource was reported.
Recommendations
CSA Global has made the following recommendations for future work at the MGP:
-- Improvements in reliability of collar survey data for historical drilling.
-- Improvements in QAQC protocols and follow up of QAQC results to ensure accurate and precise assay data.
-- Improvements to geological logging such that a reliable geological model for the prospect can be constructed and oxide weathering profiles be developed.
-- High resolution topographic survey to obtain a more detailed DTM for the area, and to accurately deplete the Mineral Resource models. Any underground workings not surveyed by aerial means, need to be assessed with regards to impact on the Mineral Resource.
-- Additional bulk density determination is required, particularly in the oxide and transitionary zones to ensure robust tonnage estimates.
-- Further metallurgical testwork should be undertaken to better characterise material within weathering horizons and domains.
-- In order to improve the confidence (classification) of future MREs at Migori, infill drilling should be considered.
-- Targeted step-out drilling is recommended to potentially increase the size of the Mineral Resource. A preliminary drill plan was compiled to assist in future drill planning (Table 3).
Table 3: Preliminary step-out drill plan
ID X Y Z Depth Dip Azimuth
-------- ---------- ------ ------ ---- --------
CSA_001 646,990 9,888,148 1,277 290 0 60
--------- -------- ---------- ------ ------ ---- --------
CSA_002 647,106 9,888,156 1,279 50 0 60
--------- -------- ---------- ------ ------ ---- --------
CSA_003 646,933 9,888,370 1,287 50 0 60
--------- -------- ---------- ------ ------ ---- --------
CSA_004 646,919 9,888,340 1,286 80 0 60
--------- -------- ---------- ------ ------ ---- --------
CSA_005 644,908 9,889,000 1,252 80 0 60
--------- -------- ---------- ------ ------ ---- --------
CSA_006 644,951 9,889,041 1,250 70 0 60
--------- -------- ---------- ------ ------ ---- --------
CSA_007 644,924 9,889,035 1,250 60 0 60
--------- -------- ---------- ------ ------ ---- --------
CSA_008 644,330 9,889,379 1,220 90 0 50
--------- -------- ---------- ------ ------ ---- --------
CSA_009 644,227 9,889,472 1,214 30 0 55
--------- -------- ---------- ------ ------ ---- --------
CSA_010 644,874 9,889,540 1,240 80 0 60
--------- -------- ---------- ------ ------ ---- --------
CSA_011 644,815 9,889,758 1,241 60 0 50
--------- -------- ---------- ------ ------ ---- --------
CSA_012 641,060 9,890,936 1,162 85 0 60
--------- -------- ---------- ------ ------ ---- --------
CSA_013 641,076 9,890,970 1,163 85 0 60
--------- -------- ---------- ------ ------ ---- --------
CSA_014 640,847 9,891,078 1,165 50 0 60
--------- -------- ---------- ------ ------ ---- --------
Competent Person Statement
The information related to the estimation of Mineral Resources in this release has been compiled by Mr Anton Geldenhuys, MEng, PrSciNat, MGSSA, MGASA of CSA Global (UK) Ltd. He is a member of a recognised professional organisation and has sufficient experience, which is relevant to the style of mineralisation and type of deposit under consideration, and to the activity he is undertaking, to qualify as a Competent Person as defined in the 2012 Edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (The JORC Code) and as defined in the Guidance Note for Mining, Oil and Gas Companies published by AIM.
CSA Global (UK) Ltd has given and not withdrawn its consent to the release of the technical information in this announcement in the form and context in which it appears.
This announcement contains inside information for the purposes of Article 7 of the Market Abuse Regulation (EU) 596/2014 as it forms part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 ("MAR"), and is disclosed in accordance with the Company's obligations under Article 17 of MAR.
For further information, please contact:
Andrew Bell 0207 747 9990 Chairman Red Rock Resources Plc
Scott Kaintz 0207 747 9990 Director Red Rock Resources Plc
Roland Cornish/ Rosalind Hill Abrahams 0207 628 3396 NOMAD Beaumont Cornish Limited
Mark Treharne 0203 700 2500 Broker Pello Capital Limited
JORC Code, 2012 Edition - Table 1
Section 1: Sampling Techniques and Data
(Criteria in this section apply to all succeeding sections)
Criteria JORC Code explanation Commentary
--------------------- -------------------------------------------------------------------------------------------------------------------------------
Sampling Nature and quality of Red Rock (2011 to 2012)
techniques sampling (e.g. cut Diamond (DD) drillholes - core diameter
channels, of 47.6 mm (NQ) and the upper weathered
random chips, or and oxidised portions at 63.5 mm (HQ)
specific and 85 mm (PQ), Core split in half using
specialised industry a diamond core saw along a marked centre
standard measurement line and half core sampled at 1 m lengths
tools appropriate to and submitted for assay.
the minerals under Reverse circulation (RC) drilling -
investigation, RC chips collected for every metre at
such as down hole drill pad. Rods flushed every 3 m on
gamma the completion of a run. Samples then
sondes, or handheld dried and split using a 50:50 riffle
XRF instruments, splitter to produce 1, 2, 3 or 4 m composites
etc.). depending on geology. Final samples
These examples should submitted to the assay laboratory weighed
not be taken as approximately 500 g each.
limiting Historical drilling
the broad meaning of Auvista Minerals NL (Auvista) RC drilling
sampling. - RC chips collected on site at 1 m
Include reference to intervals and initially composited to
measures taken to 4 m samples onsite; later in program
ensure the 1 m samples were taken to the camp
sample representivity prep-facility for compositing.
and the appropriate Kansai Mining Corporation Ltd (KMC)
calibration of any DD drilling - HQ and NQ diameter drill
measurement core split in half using a diamond core
tools or systems saw along a marked centre line. Half
used. core sampled and submitted for assay.
Aspects of the
determination
of mineralisation
that
are Material to the
Public Report.
In cases where
'industry
standard' work has
been
done this would be
relatively
simple (e.g. 'reverse
circulation drilling
was used to obtain 1
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 is
coarse
gold that has
inherent
sampling problems.
Unusual
commodities or
mineralisation
types (e.g. submarine
nodules) may warrant
disclosure of
detailed
information.
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Drilling Drill type (e.g. Red Rock (2011 to 2012)
techniques core, Diamond core diameter was 47.6 mm diameter
reverse circulation, (NQ) and shallow and oxidised upper
open-hole hammer, portions drilled using 85 mm (PQ) and
rotary 63.5 mm (HQ) core diameters.
air blast, auger, Drill core from Kakula-Kalange-Munyu
Bangka, (KKM), Kakula-Kalange-Munyu West (KW)
sonic, etc.) and and Nyanza (NZ) were orientated using
details a Reflex EZ-Trac(TM). None of the drilling
(e.g. core diameter, at Gori Maria (GM) and MK were orientated.
triple or standard Auvista (1994 to 2002)
tube, Pre-1995 - RC drilling using Smith Capital
depth of diamond 10R3H rig fitted with an Atlas Copco
tails, 750 cfm/400 psi compressor. Holes drilled
face-sampling bit or with a 5" (125 mm) Halco face sampling
other type, whether hammer on a 4" (100 mm) RC rod string.
core is oriented and Post-1996 - Smith Capital 14R6H rig
if so, by what mounted on a Sammil 50 truck with an
method, Atlas Copco 960 cfm/360 psi compressor
etc.). and a 4" RC rod string. A second rig
was purchased in March 1997 which was
a modified and improved version of the
first rig with additional air capacity
(1920 cfm/720 psi).
KMC (2002 to 2009)
Boyles BB37 mobile/skid mounted drill
rig with the capacity to drill HW (for
hole portions requiring casing), HQ
and NQ sized drill core. Five holes
still had orientation marks visible
- but method utilised is unknown.
The 592 drillholes used in the Mineral
Resource estimate (MRE) comprised: diamond
core drilling (26%), RC pre-collar and
DD core tails (4%), RC drilling (70%).
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Drill sample Method of recording Red Rock (2011 to 2012)
recovery and assessing core DD recovery was recorded, and no issues
and reported. For the verification drilling,
chip sample drillers made use of drilling fluids
recoveries and shortened drill runs to maximise
and results assessed. core recovery in areas of broken ground.
Measures taken to In the upper weathered and oxidised
maximise parts of the drillholes, larger core
sample recovery and diameters (HQ and PQ) were used.
ensure representative RC recoveries were a concern in NZ due
nature of the to downhole water that resulted in potential
samples. for contamination in the cyclone. In
Whether a GM, poor recoveries were associated
relationship with poor driller experience and procedures
exists between sample and practices. GM average recovery was
recovery and grade 62.3%. All other areas, RC recovery
and averaged 90%.
whether sample bias No relationship between recovery and
may have occurred due grade, therefore no bias was observed.
to preferential Historical drilling
loss/gain Recoveries for historical DD and RC
of fine/coarse drilling not recorded. No information
material. is available regarding how recovery
was maximised for the historical drilling.
Any relationship between grade and recovery
cannot be investigated for the historical
data.
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Logging Whether core and chip Red Rock (2011 to 2012)
samples have been All RC holes were logged at the drill
geologically site by the supervising geologist. All
and geotechnically DD core was logged at the Migori Camp.
logged All logging was done using templates
to a level of detail compiled by CSA Global (UK) Limited
to support (CSA Global). Observations included
appropriate colour, oxidation, texture, grain size,
Mineral Resource mineralisation, alteration, and lithology
estimation, code. All geological logging was recorded
mining studies and on paper and then digitised.
metallurgical 37 of the Red Rock Resources Plc (Red
studies. Rock) DD holes and five of the KMC holes
Whether logging is had orientated structures logged. In
qualitative summary, there were five holes from
or quantitative in KKM, 18 holes from KW and 14 holes from
nature. NZ.
Core (or costean, Rock quality designation (RQD) data
channel, for cored drillholes was recorded.
etc) photography. Historical drilling
The total length and Auvista RC drilling - hard copy data
percentage of the was scanned and captured digitally by
relevant Red Rock. The same database library
intersections logged. was used as for the Red Rock drilling.
No information on KMC logging was available.
Geotechnical logging was not undertaken.
It was not possible to define the nature
of historical logging as qualitative
or quantitative, nor was it possible
to define the total length logged, as
useful logging data was unavailable.
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Subsampling If core, whether cut Red Rock
techniques or sawn and whether Drill core was sawn in half along a
and sample quarter, half or all marked centre line using a DD core saw.
preparation core taken. Same half of the core was consistently
If non-core, whether sampled, and most samples submitted
riffled, tube for assay were 1 m in length.
sampled, RC samples were dried and split using
rotary split, etc and a 50:50 riffle splitter to produce 1
whether sampled wet m, 2 m, 3 m or 4 m composites, depending
or dry. on geology. Final samples submitted
For all sample types, to the assay laboratory weighed approximately
the nature, quality 500 g each.
and appropriateness All Red Rock samples were crushed on
of the sample site and a split sent to ALS Mwanza
preparation where the samples were milled, and pulps
technique. then sent to ALS Johannesburg where
Quality control they were assayed.
procedures Auvista
adopted for all Limited details available regarding
sub-sampling how the samples were split and composited.
stages to maximise The sample preparation was done at an
representivity onsite facility (purchased from Engineering
of samples. and Sampling Systems, Australia in 1995)
Measures taken to with a 10-12 sample per hour capacity.
ensure From 1996, samples were reduced to 170
that the sampling is g pulps before shipment. Samples were
representative of the sent to Analabs Laboratories Pty Ltd
in-situ material (Western Australia) as noted from available
collected, assay certificates. No additional details
including for on the sample preparation are available.
instance KMC
results for field DD drilling - HQ and NQ diameter drill
duplicate/second-half core split in half using a diamond core
sampling. saw along a marked centre line. Half
Whether sample sizes core sampled and submitted for assay,
are appropriate to Sample preparation and analysis done
the at Humac Laboratories in Mwanza. Sample
grain size of the prep using P10 code included drying,
material jaw crushing to --6 mm and cone crushing
being sampled. to -2 mm, and riffle splitting to produce
a 1 kg sample. Sand washing between
samples was used where visible gold
was noted to avoid contamination between
high-grade gold samples.
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Quality The nature, quality Red Rock
of assay and appropriateness Samples were prepared by ALS in Mwanza
data and of the assaying and and assayed by ALS in Johannesburg.
laboratory laboratory procedures The assay methods were:
tests used and whether the * Au-AA26 (5 g fire assay with a AAS finish) for gold
technique is (range 0.01-100 ppm Au)
considered
partial or total.
For geophysical * ME-OG62 (four-acid digest and AES finish) for silver,
tools, copper, lead, and zinc.
spectrometers,
handheld
XRF instruments, etc, Auvista
the parameters used The samples were analysed at Analabs
in determining the in Western Australia in 1996 to 1997.
analysis The 4 m composites were sent for fire
including instrument assay with aqua regia digest from a
make and model, 30 g charge with an AAS finish. Samples
reading >0.15 g/t Au had individual 1 m samples
times, calibrations re-sent for fire assay from a 50 g charge
factors applied and with an AAS finish. Base metal geochemical
their derivation, data was obtained from pressed powder
etc. pellet XRF analyses.
Nature of quality KMC
control Samples were analysed at Humac Laboratories
procedures adopted between March 2001 and January 2010.
(e.g. A straight fire assay was used (gold
standards, blanks, four-method) on a 50 g sample with an
duplicates, AAS finish. High grade-samples were
external laboratory routinely checked at the laboratory
checks) and whether with duplicate and sometimes triplicate
acceptable levels of assays. A set of screen fire assays
accuracy (i.e. lack were carried out on selected samples
of bias) and from the NZ prospect due to the common
precision presence of visible and coarse gold.
have been Gold assays were recorded for drillholes
established. only at Kakula, GM, NZ, and MK. At Macalder,
both copper and silver assays were carried
out in addition to gold using standard
AA procedures (GAR Code). Assays were
usually available within a week of delivery,
allowing regular appraisal of the drilling
program. Several drillholes required
additional core splitting to complete
assaying unsuspected mineralised intercepts.
QAQC protocols
Red Rock
Included insertion of:
* Certified reference materials (CRM) sourced initially
from Gannet Holdings in Perth and later made use of
CRMs sourced from AMIS in Johannesburg.
* Blank materials comprising non-certified alluvial
sand, and later on, blank material sourced from AMIS.
The CRMs and blanks were inserted at
a ratio of approximately 10 per 100
samples.
Duplicate samples comprising field duplicates
prepared on site by crushing the half
core and splitting the sample using
a 50:50 riffle splitter. Inserted at
a ratio of 1 per 20 samples.
Sample pulps were sent to Genalysis-Johannesburg
(now part of the Intertek Group) the
check laboratory. However, due to insufficient
material only 44 of the 646 samples
submitted could be assayed and results
reported. These samples were analysed
by a 50 g fire assay with an AA finish.
Overall, the quality of the results
reported by ALS for the Red Rock drilling
are considered sufficiently accurate
and precise for use in the MRE.
Auvista
The samples were analysed at Analabs.
Scant details were provided on the Auvista
assay results. Procedures indicate that
the following was implemented:
* 1 in 10 samples is a duplicate
* 1 in 20 samples is a triplicate
* 1 in 40 samples is a blank, alternating with a
high-grade standard.
Blanks were barren granite and high-grade
standard samples were made from a Kakula
drill sample which was crushed and thoroughly
mixed homogenised. The average grade
was approximately 1.6 g/t Au. Triplicate
samples were analysed independently
by other labs.
The review of the Auvista QAQC results
found:
* Naming of CRMs (standards) and blanks was not always
consistent. They were named "BLANK", "STD", "STDL",
or "STDH". Two populations of standards ("STD1" and
"STD2") and a blank were identified from these
results.
* Blank results were acceptable.
* STD1 has an acceptable precision, STD2 has a poorer
precision.
* Duplicates and triplicates had an acceptable
correlation, with some outliers at higher grades
indicating that the gold mineralisation was nuggety.
* No lab check results were available.
KMC and Santa Barbara QAQC
The QAQC results from the gold assays
reported from March 2001 to January
2010. Samples were analysed at SGS and
at Humac laboratories. In summary the
following were noted:
* Lab standards: Only a few results available, but no
issues.
* Blanks (client and lab): No issues.
* Field duplicates: Poor correlation, but no
significant bias.
Summary of QAQC samples per company/campaignCompany QAQC Count of % Total % Original Count of % Lab
category samples samples samples lab checks checks
------------ ----------- ----------- ---------- ---------- -----------
Red Rock Samples 10,121 85.69% 100.00%
-----------
Duplicates 670 5.67% 6.62% 1551 13.13%
CRMs 1,020 8.64% 10.08% 909 7.70%
Umpires 44 0.43%
------------------------ ----------- ----------- ---------- ---------- -----------
Total 11,811 100.00%
------------------------ ----------- ----------- ---------- ---------- -----------
Auvista Samples 14,761 91.55% 100.00%
-----------
Duplicates 1,000 6.20% 6.77% 0 0.00%
Triplicates 226 1.40% 1.53% 0 0.00%
CRMs 137 0.85% 0.93% 0 0.00%
------------------------ ----------- ----------- ---------- ---------- -----------
Total 16,124 100.00%
------------------------ ----------- ----------- ---------- ---------- -----------
KMC and
Santa
Barbara Samples 8,034 99.46% 100.00%
-----------
Duplicates 26 0.32% 0.32% 0 0.00%
Triplicates 5 0.06% 0.06% 0 0.00%
CRMs 13 0.16% 0.16% 44 0.54%
------------------------ ----------- ----------- ---------- ---------- -----------
Total 8,078 100.00%
------------------------ ----------- ----------- ---------- ---------- -----------
Notes:
* Samples refers to original samples for assay
* Duplicates refers to field duplicate and lab pulp
splits respectively
* CRMs (standards) and blanks (client and lab
respectively)
* Umpires: Third party assays (not included in total
no. of samples)
* % Total Samples: Percent of total samples (including
QAQC samples) submitted for each company
* % Original samples: Percent of original samples
(excluding QAQC samples) submitted for each company
* % Lab Checks: Percent of total samples (including
QAQC samples) submitted for each company
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Verification The verification of No independent verification sampling
of sampling significant of the available historical drill core
and assaying intersections or RC chips, or Red Rock drill core
by either independent or RC material was done by CSA Global.
or alternative As part of the verification process
company of the historical data, the following
personnel. was done by Red Rock:
The use of twinned * Red Rock drilled and sampled 111 infill holes at MK,
holes. KKM, KW, NZ, and GM. The geological and assay data
Documentation of collected in this exercise was compared with the
primary historical data and found it correlated well with the
data, data entry historical data and thus supported their inclusion in
procedures, the MRE. The infill drilling also served to decrease
data verification, the hole spacing and improve confidence in the MRE.
data
storage (physical and
electronic) * Acquisition and collation of historical exploration
protocols. data by Red Rock into a digital format.
Discuss any
adjustment
to assay data. * Review of the historical databases and sample assay
QAQC data (where available, was done).
* Field confirmation of preserved drillhole collar
positions and resurveying with a Trimble differential
global positioning system (DGPS). Historical collars
had previously used a local grid and subsequent
transformations were unreliable.
* Downhole survey camera shots were re-read and
evaluated on a prospect-by-prospect basis.
* Improved density data was collected.
* Improved metallurgical data was collected.
* An improved digital terrain model (DTM) was generated
for the entire Migori area.
* Where possible, historical assay data were checked
against original lab certificates, downhole graphical
logs, and digital data (stored as .csv files).
The attached report contains a thorough
review of the work done to verify the
historical data.
Where possible, the data was validated
and captured with appropriate metadata,
and all data was stored in a single
database managed by CSA Global and Red
Rock.
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Location Accuracy and quality The Red Rock drillholes were surveyed
of data of surveys used to using a Trimble Pathfinder Pro-XRS differential
points locate DGPS receiver coupled with an L1 GPS/satellite
drillholes (collar differential antenna to collect coordinates
and and provided sub-metre level accuracy.
downhole surveys), Grid system used: UTM36S-ARC1960.
trenches, Historical drillhole coordinates were
mine workings and in a local grid and were transformed
other by Red Rock. All preserved historical
locations used in collars were surveyed by Red Rock (a
Mineral total of 133 were located) and an affine
Resource estimation. transformation applied.
Specification of the The topographic surfaces onto which
grid system used. the drillholes were draped comprised:
Quality and adequacy 25 m x 25 m DTM for KW and NZ, surveyed
of topographic using the onsite Trimble DGPS.
control. 10 m x 10 m DTM was acquired for the
rest of the area during the airborne
geophysical survey in 2010 but has a
less well constrained RL than the DGPS
DTM.
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Data spacing Data spacing for Drilling was done on a semi-regular
and reporting grid over each of the deposits. Drillhole
distribution of Exploration intersections are spaced at between
Results. 35 m and 50 m along-strike (and up to
Whether the data 100 m in places, often around the edge
spacing of individual deposits) and 30-50 m
and distribution is down-dip (in places the spacing may
sufficient to be closer at +/-10-20 m).
establish The infill drilling program by Red Rock
the degree of comprised: Prospect No. of Metres drilled
geological holes
and grade continuity ------- ---------------
appropriate for the KKM 31 3,425.05
Mineral Resource and KW 33 4,292.66
Ore Reserve GM 17 1,808.03
estimation MK 7 963.68
procedure(s) and NZ 23 2,851.88
classifications ---------- ------- ---------------
applied. Total 111 13,341
Whether sample ---------- ------- ---------------
compositing
has been applied. In summary, the drilling used for the
MRE comprised 592 drillholes: Company No. of % total
holes
------- --------
Auvista 394 66.6
KMC 34 5.7
Red Rock 111 18.8
Santa Barbara 52 8.8
Unifario 1 0.2
--------------- ------- --------
Total 592 100
--------------- ------- --------
The drillhole spacing is acceptable
to establish reasonable grade and geological
continuity.
1 m composites were used for the estimation
of gold grade.
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Orientation Whether the The drillholes (Red Rock and historical)
of data orientation were drilled along lines orientated
in relation of sampling achieves at an azimuth of 025deg which is orthogonal
to unbiased sampling of to the northwest-southeast strike of
geological possible structures the deposits. Drillholes were inclined
structure and the extent to at -60deg.
which The drilling was orientated such that
this is known, the mineralisation was intersected orthogonally
considering so that the mineralised widths approximate
the deposit type. true widths.
If the relationship No material sampling bias was identified
between the drilling due to sample orientation.
orientation and the
orientation of key
mineralised
structures is
considered
to have introduced a
sampling bias, this
should be assessed
and
reported if material.
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Sample The measures taken to All drill samples were prepared at Red
security ensure sample Rock's Mikei Camp which was permanently
security. guarded and enclosed by a perimeter
fence. All samples, once prepared, were
then transported directly from the camp
to the laboratory in Mwanza under supervision
of a senior geologist.
ALS took responsibility for the sample
security and transport once the samples
arrived in Mwanza and all samples were
accounted for.
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Audits The results of any As part of the Mineral Resource estimation
or reviews audits process, CSA Global undertook an extensive
or reviews of review of the historical data and associated
sampling protocols, the Red Rock data and protocols
techniques and data. and a comparison of the various datasets
to establish the validity and suitability
of the data for inclusion into the MRE.
------------ --------------------- -------------------------------------------------------------------------------------------------------------------------------
Section 2: Reporting of Exploration Results
(Criteria listed in the preceding section also apply to this section)
Criteria JORC Code explanation Commentary
---------------------------------------------------------- -----------------------------------------------------------
Mineral Type, reference name/number, The project area comprises two prospecting
tenement location and ownership licences, PL/2018/0202 and PL/2018/0203
and land including agreements re-issued on 3 August 2020 under the
tenure or material issues with Mining Act 2016 ("2016 Act"). They are
status third parties such as valid for a period of three years from
joint ventures, partnerships, 3 August 2020 to 2 August 2023. The
overriding royalties, licences are held by Mid Migori Mining
native title interests, Company Limited (Mid Migori) and provides
historical sites, wilderness the holder the right to prospect for
or national park and "Precious Metal Group of Minerals" which
environmental settings. includes gold ( Table 2 ).
The security of the The two licences were previously allocated
tenure held at the time as special prospecting licences (SPL122
of reporting along with and SPL202).
any known impediments Red Rock holds a 100% interest in both
to obtaining a licence licences through the agreements of 2015
to operate in the area. and 2018 with Mid Migori.
No information on royalties etc., native
title interests, historical sites and
wilderness or national park settings
were provided.
-------------- ---------------------------------------------------------- -----------------------------------------------------------
Exploration Acknowledgment and appraisal The MREs for the five prospects is heavily
done by of exploration by other reliant on historical data. Approximately
other parties parties. 81% of the holes used in the MRE were
drilled by historical operators. In
particular, Auvista data constitutes
67% of the holes in the current MRE.
Companies and related work completed
by years:
* 1930s - Discovery of gold in the Migori District and
small-scale mining by colonial individuals and
companies through to the 1950s. Macalder and Nyanza
mines continued producing copper and gold to the
1960s.
* 1940 to 1942 - RM Shackleton completed geological
mapping at 1:125,000 scale which was published in
1946 by the Mining and Geological Department, Kenya
Colony.
* 1959 to 1960 - Hunting Geophysics, McPhar Geophysics
Ltd (AFMAG) and Lundberg Exploration Ltd undertook
airborne electromagnetic and ground geophysical
surveys.
* 1963 - Development at Nyanza mine by the operators of
Macalder mine, including pitting, trenching, ground
geophysics and diamond drilling.
* 1966 - Mining operations ceased at Macalder due to
ore depletion.
* 1964 to 1969 - The UN Special Fund sponsored the BGS
in a program of exploration for mainly base metals
but also for gold. The BGS followed up geophysical
anomalies and carried out geological mapping, surface
geochemistry and limited DD drilling. No significant
gold or base metal prospects delineated, some
anomalies were left untested and only an incomplete
record of this work is available in a report on
copper in Kenya by L.D. Sanders in 1964.
* 1977 - Terra Surveys completed an INPUT airborne
electromagnetic and magnetic survey over the central
part of the Migori Greenstone Belt. Hard copy contour
maps and electromagnetic anomaly plans were
available. Survey data have since been digitally
captured by Leeds University.
* 1979 to 1982 - UN Funds for Natural Resource
Development sponsored consultant, R. Hutchinson, to
review and re-interpret RM Shackleton's work on the
regional geology. A brief geological summary is
available from this work. The UN also commissioned
Hunting Geophysics to re-interpret all the
geophysical surveys in the area. Target areas were
tested with ground geophysics (pulse electromagnetic,
gravity and magnetics), geochemistry, trenching and
3,150 m diamond drilling.
* 1980 to 1986 - Unifario Ores Ltd (UOL) completed work
on the Macalder tailings and NZ area. Work included
trenching, bulk testing of alluvial material, limited
shallow diamond drilling and estimation of Ore
Reserves, but never proceeded into production.
* 1986 - Exploration Consultants International Ltd
(ECI) (originally Unifario) contracted Michael Cotts
International and Mackay and Schnellman to complete a
prefeasibility study on the work completed by UOL. No
reports relating to these studies were located and
were not available for review, however they have been
referred to by both Auvista (1988) and Tanganyika
Gold Ltd (TGL) (Due Diligence, 1997).
* 1988 to 1994 - Migori Gold Mining Company (MGM),
formerly ECI, signed a joint venture agreement with
Santa Barbara (Kenya) Ltd (SBK). SBK funded
approximately 5,000 m of diamond drilling in 39 holes
at MK and GM. SBK engaged MSL to complete this work
as well as MREs for MK. Following this, a stamp mill
and cyanide recovery plant were installed in 1991.
The project was hampered by numerous problems and
only operated for a year. The North Queensland
Company Ltd also conducted a data study on the
projects in 1988 and concluded the projects were a
worthy target but did not engage in any activities in
Kenya.
* 1994 to 2002 - Auvista (a subsidiary of Panorama
Resources NL) entered into a joint venture agreement
with MGM to earn a 60% interest in Migori from an
expenditure of US$2.2 million. Auvista spent
approximately US$5 million from 1994 to 2001. Auvista
completed extensive exploration soil sampling
programs. Following positive soil geochemical results
which focused on the KKM, GM, MK, and NZ targets,
approximately 55,000 m of RC drilling was completed
for over 600 holes at these lode gold prospects
following which Mineral Resources were estimated in
the 1990s. During this time, a regional mapping
exercises was undertaken by consultant geologist, Jim
Thornett over both tenements in 1996. From this
exercise, four 1:25,000 scale solid and outcrop
geology maps were produced covering the two licence
areas. A detailed report also accompanied the maps
and included a list of targets for exploration. These
provided the focus for most of the work completed by
Auvista from that time onwards.
* 1997 to 2002 - TGL completed a due diligence on these
projects following which in 1998 TGL took over
Panorama Resources NL and continued general
exploration across the two licences.
* In 2001 and 2002, TGL cited depreciation of gold
prices as reason for lack of further investment at
Migori.
* 2002 to 2009 - KMC acquired the projects from MGM in
2002. Data was apparently compiled into a digital
format and additional re-assaying completed. An
additional +/-3,500 m of confirmatory DD holes were
drilled at all prospects including some infill
drilling in an attempt to tighten geological models
and produce internal mineral estimates. These
estimates were verified by D.A.S Hopkins of Ddraig
Minerals Developments and publicly released in 2006
in an NI 43-101 Technical Report. Polygonal estimates
with wireframes were used to calculate volumes at
each locality.
* 2009 to present - Red Rock entered into a joint
venture, purchase and sale agreement with KMC.
* 2011 - Red Rock completed an infill drill program,
totalling 111 holes for 13,341 m at KKM, KW, MK, GM,
and NZ.
* 2012 - Red Rock/CSA Global report an updated MRE for
the Migori prospects.
-------------- ---------------------------------------------------------- -----------------------------------------------------------
Geology Deposit type, geological The Migori Belt forms a small part of
setting and style of the Nyanza Greenstone Belt which is
mineralisation. an extensive region of Archean greenstone
rocks within the Tanzanian Craton located
in northern Tanzania, western Kenya,
and southeast Uganda. The Nyanza Greenstone
Belt is divided into the Northern and
Southern Terrains. The Southern Terrain
is predominantly a volcaniclastic suite
(Nyanzian Group) and associated intrusives
while the Northern Terrain is dominated
by the marine metasediments of the Kavirondian
Group.
The host rocks within the tenements
comprise predominately intermediate
to felsic volcanics and associated volcaniclastics,
inter-bedded with subordinate basaltic
to andesitic lavas and siliciclastic
interflow sediments. Generally, the
igneous suite is dominated by intermediate
andesites and rhyolites with an abundance
of crystal tuffs, however Nyanza is
dominated by metabasalts. Intercalated
with these metavolcanics are metasediments
including greywackes and graphitic shales.
Banded Iron formation also occurs throughout
the volcano sedimentary pile and regionally
exploration results appear to highlight
these as future targets for gold exploration.
Two main deposit types are recognised
in the area:
* Volcanogenic massive sulphide (VMS) ascribed to the
historical Macalder Mine.
* Orogenic (lode) gold prospects ascribed to the KKM,
KW, GM, NZ, and MK prospects and also includes those
in the Lake Victoria Greenstone Belt in northwest
Tanzania (to the south of the Nynaza Belt) including
North Mara (Barrick Gold), Golden Pride (Resolute)
and Geita (AngloGold Ashanti).
Lode gold
The Migori belt is host to numerous
quartz vein hosted gold occurrences,
which are exploited by artisanal miners
(KKM, KW, GM, NZ, and MK). These lodes
occur as structurally controlled quartz
stockworks and veins within shear zones.
For most prospects, gold mineralisation
is close to surface.
Gold mineralisation is associated with
emplacement of quartz vein and porphyry
intrusions resulting from granitic intrusions.
This is associated chlorite, sericite
and carbonate alteration assemblages
along with silicification which increases
within the shear zone, particularly
along mineralised zones where quartz
flooding and blue-grey sulphidic quartz
stockworks are associated with maximum
gold grades. Accessory sulphide assemblages
often accompany mineralisation, however
barren assemblages also host sulphides.
Pyrite is the most widespread, with
pyrrhotite also common and minor arsenopyrite.
Each of the five prospects (KKM, KW,
MK, GM, NZ) form individual mineralised
domains that are located within the
main shear zone which has a strike length
of over 7.5 km northwest-southeast,
with KKM located roughly at its centre.
This shear zone forms a large magnetic
low of the same orientation. Between
KKM and GM a pervasive north-northwest
trending kilometre-scale transverse
fault (with apparent dextral movement)
is visible in the magnetic imagery along
which the Macalder VMS deposit is located.
Most lode gold mineralisation occurs
within the shear zone, in close proximity
to the granite-greenstone contact. The
lodes occur as structurally controlled
quartz stockworks and veins within sheared
zones that range between 1 m and 30
m in thickness. These stockwork or vein
systems will often have a plunge along
steeply dipping shear planes and are
generally discontinuous. Structural
studies completed by Olang (2012(3)
) have identified two dominant fault
systems; a north-northwest to south-southeast
dextral strike slip system with a northeast-southwest
conjugating set. En-echelon conjugate
sets are common for shear zone systems
and could account for the high number
of near horizontal down hole orientated
structures.
Generally, lodes are inconsistent in
grade and can be discontinuous between
50 m sections (this is particularly
the case for NZ). However, majority
of the core mineralisation is typically
continuous along a central portion of
each prospect. Maximum grades are associated
with quartz vein stockworks and/or lithological
contacts such as between quartz-eye
porphyries and graphitic shales.
-------------- ---------------------------------------------------------- -----------------------------------------------------------
Drillhole A summary of all information Exploration results not being reported.
information material to the understanding The relative location of the Red Rock
of the exploration results drillholes (RC and DD) are presented
including a tabulation Figure 21 (Section 6.1 ).
of the following information
for all Material drillholes:
* easting and northing of the drillhole collar
* elevation or RL (Reduced Level - elevation above sea
level in metres) of the drillhole collar
* dip and azimuth of the hole
* down hole length and interception depth
* 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 In reporting Exploration Exploration results are not being reported
aggregation Results, weighting averaging as part of this work. No data aggregation
methods techniques, maximum has been used to report Exploration
and/or minimum grade Results.
truncations (e.g. cutting No metal equivalents have been applied.
of high grades) and
cut-off grades are usually
Material and should
be stated.
Where aggregate intercepts
incorporate short lengths
of high-grade results
and longer lengths of
low-grade results, the
procedure used for such
aggregation should be
stated and some typical
examples of such aggregations
should be shown in detail.
The assumptions used
for any reporting of
metal equivalent values
should be clearly stated.
-------------- ---------------------------------------------------------- -----------------------------------------------------------
Relationship These relationships The drilling was orientated such that
between are particularly important the mineralisation was intersected orthogonally
mineralisation in the reporting of so that the mineralised widths approximate
widths Exploration Results. true widths.
and intercept If the geometry of the The drillholes (Red Rock and historical)
lengths mineralisation with were drilled along lines orientated
respect to the drillhole at an azimuth of 025deg which is orthogonal
angle is known, its to the northwest-southeast strike of
nature should be reported. the deposits. Drillholes were inclined
If it is not known and at -60deg.
only the downhole lengths
are reported, there
should be a clear statement
to this effect (e.g.
'downhole length, true
width not known').
-------------- ---------------------------------------------------------- -----------------------------------------------------------
Diagrams Appropriate maps and Relevant figures are provided in this
sections (with scales) report.
and tabulations of intercepts
should be included for
any significant discovery
being reported These
should include, but
not be limited to a
plan view of drillhole
collar locations and
appropriate sectional
views.
-------------- ---------------------------------------------------------- -----------------------------------------------------------
Balanced Where comprehensive No reporting of Exploration Results.
reporting reporting of all Exploration
Results is not practicable,
representative reporting
of both low and high
grades and/or widths
should be practiced
to avoid misleading
reporting of Exploration
Results.
-------------- ---------------------------------------------------------- -----------------------------------------------------------
Other Other exploration data, No other exploration data to report.
substantive if meaningful and material,
exploration should be reported including
data (but not limited to):
geological observations;
geophysical survey results;
geochemical survey results;
bulk samples - size
and method of treatment;
metallurgical test results;
bulk density, groundwater,
geotechnical and rock
characteristics; potential
deleterious or contaminating
substances.
-------------- ---------------------------------------------------------- -----------------------------------------------------------
Further The nature and scale Additional work proposed includes:
work of planned further work * Strategic Mineral Resource definition from infill and
(eg tests for lateral geostatistical drilling, including areas identified
extensions or depth outside the RPEEE pit shell which should be drilled
extensions or large-scale and included into future updates of the RPEEE pit
step-out drilling). shells
Diagrams clearly highlighting
the areas of possible
extensions, including * Additional twinning of historical holes in the
the main geological central zones of each deposit
interpretations and
future drilling areas,
provided this information * Metallurgical testwork to better characterise the
is not commercially weathered and fresh domains
sensitive.
* Re-survey collar positions of all historical holes to
improve reliability
* Improvements to the geological logging to better
define the oxide and fresh domains
* Improvements on the QAQC protocols
* More detailed topographical survey, this should
include the surface artisanal workings
* Volumetric surveys of the underground historic
workings for Mineral Resource depletion
* Additional bulk density sampling of all material,
particularly from the oxide and transition zones
-------------- ---------------------------------------------------------- -----------------------------------------------------------
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 Measures taken to The integrity of the database was tested
integrity ensure that data has by means of importing the data into Micromine
not been corrupted and examining statistics and histograms
by, for example, transcription of variables. Any transcription errors
or keying errors, entered into the digital database from
between its initial hardcopy logs or certificates, would show
collection and its up either as an importing issue into Micromine
use for Mineral Resource (identifies any overlaps or gaps in data),
estimation purposes. or in the statistics and histograms of
Data validation procedures grade values (in the form of unexpected
used. values).
It is evident from analysis of the QAQC
data, that some CRMs and blanks were mislabelled.
These were however identified.
--------------- -------------------------------- -------------------------------------------------------------
Site visits Comment on any site A four-day site visit was completed as
visits undertaken part of CSA Global 's initial review by
by the Competent Person Andrew Chubb (Senior Geologist, CSA Global
and the outcome of who has since left the employ of CSA Global)
those visits. from 11 August 2009, along with Joe Crummy
If no site visits (Consulting Geologist) and Mike Nott (Director,
have been undertaken Red Rock Resources). In September 2011,
indicate why this a second site visit by Thomas Branch (Geologist,
is the case. CSA Global who has since left the employ
of CSA Global) was completed to gain an
understanding of the drill logging and
sampling methodologies of Red Rock's infill
drill program.
No site visit has been undertaken by the
Competent Person as part of the 2021 MRE;
however, there is no material new data
since reporting the 2012 MRE, and the
Competent Person is satisfied to rely
on the previous site visits as both Andrew
Chubb and Thomas Branch are known to CSA
Global and were trusted employees at the
time of the employment.
--------------- -------------------------------- -------------------------------------------------------------
Geological Confidence in (or Geological logging and assay data was
interpretation conversely, the uncertainty used in the interpretation of the geological
of) the geological model. Red Rock provided cross sections
interpretation of of interpreted geology and mineralisation
the mineral deposit. to CSA Global , which formed the basis
Nature of the data of the 2D sectional interpretation undertaken
used and of any assumptions in Micromine.
made. Red Rock geologists generated a suite
The effect, if any, of individual wireframes to model the
of alternative interpretations oxidation surfaces for each prospect.
on Mineral Resource These were created in section view, using
estimation. strings that were snapped to drillhole
The use of geology traces. Weathering and oxidation details
in guiding and controlling for boreholes were taken from Red Rock
Mineral Resource estimation. logging data as well as a relatively well
The factors affecting organised Microsoft Excel database compiled
continuity both of by Auvista from their drillholes. These
grade and geology. two datasets were combined and formed
the basis of Red Rock's interpretation.
These were supplied to CSA Global and
were used to code all blocks below the
topography.
CSA Global calculated potential mining
composites in Datamine (using the COMPSE
process). Composites had a minimum width
of 3 m, allowing for a maximum 2 m of
internal waste. The composites were produced
at a range of lower cut-off grades from
0.1 g/t Au to 2.0 g/t Au.
A statistical review was undertaken of
the composites produced at each lower
cut-off grade. They were reviewed by relative
volume, % dilution, % ore lost and ore
grade. It was decided that the 0.25 g/t
Au composites would best define the boundary
between background gold and potentially
economic gold. This was supported by a
preliminary sectional assessment of the
composites using Micromine.
The 0.25 g/t Au threshold was used as
the boundary for mineralisation, with
the 0.5 and 1 g/t Au composites being
used to guide the mineralised interpretation,
so that higher grade zones were linked
down-dip and along-strike, according to
the current geological and mineralisation
model prepared by Red Rock.
Surveyed artisanal surface workings were
used to guide the extension of mineralised
zones at surface and along strike, where
appropriate.
Mineralised domains for each of the five
deposits were extended halfway between
drillholes at the termination of mineralisation,
in both dip and strike planes.
KKM consists of 17 broadly continuous
(between 200 m and 800 m strike length)
zones which dip steeply to the southwest.
KW and NZ consist of steeply dipping units,
striking southeast-northwest dipping steeply
to the southwest.
GM demonstrates a similar strike orientation
but consisted of two groups of domains
which differ in dip. One set was steeply
dipping to the southwest, the other shallow
dipping to the southwest.
Domain 1 at MK was modelled from a thin
unit of mineralised quartz porphyry. This
unit has been highly brecciated and contains
disseminated sulphide mineralisation.
It is continuous along strike and down
dip. Other domains were based upon quartz
veining and sulphide mineralisation and
are less continuous along-strike and down-dip.
A reasonable amount of confidence can
be placed in the geological interpretation.
CSA Global is not aware of any alternative
interpretations.
Drilling data shows reasonable grade and
geological continuity along strike and
down dip.
--------------- -------------------------------- -------------------------------------------------------------
Dimensions The extent and variability The KKM mineralisation is 2,110 m along-strike,
of the Mineral Resource 270 m deep with lodes occurring across
expressed as length a 320 m wide zone, with the widest continuous
(along strike or otherwise), zone being approximately 80 m in width.
plan width, and depth The Mineral Resource reported in the RPEEE
below surface to the pit shell is 1,770 m along-strike, 190
upper and lower limits m deep and spans a 270 m wide zone.
of the Mineral Resource. The MK mineralisation is 830 m along-strike,
120 m deep with lodes occurring across
a 200 m wide zone, with the widest continuous
zone being approximately 10 m in width.
The Mineral Resource reported in the RPEEE
pit shell is 830 m along-strike in several
pits, 100 m deep and spans a 40 m wide
zone.
The KW mineralisation is 800 m along-strike,
180 m deep with lodes occurring across
a 450 m wide zone, with the widest continuous
zone being approximately 15 m in width.
The majority of the Mineral Resource reported
in the RPEEE pit shell is 450 m along-strike
in several pits, 100 m deep and spans
a 60 m wide zone.
The NZ mineralisation is 680 m along-strike,
200 m deep with lodes occurring across
a 210 m wide zone, with the widest continuous
zone being approximately 20 m in width.
The Mineral Resource reported in the RPEEE
pit shell is 350 m along-strike, 140 m
deep and spans a 200 m wide zone.
The GM mineralisation is 670 m along-strike,
210 m deep with lodes occurring across
a 240 m wide zone, with the widest continuous
zone being approximately 35 m in width.
The Mineral Resource reported in the RPEEE
pit shell is 430 m along-strike, 180 m
deep and spans a 140 m wide zone.
--------------- -------------------------------- -------------------------------------------------------------
Estimation The nature and appropriateness The geological modelling and estimation
and modelling of the estimation were done in Micromine.
techniques technique(s) applied Domain wireframes created in the geological
and key assumptions, interpretation were used to code drillhole
including treatment assays. All assays that were located within
of extreme grade values, the domain wireframes were assigned the
domaining, interpolation appropriate domain code. Data outside
parameters and maximum the domain wireframes were removed from
distance of extrapolation the dataset for the purposes of grade
from data points. estimation.
If a computer assisted Data was separated into the five prospects
estimation method and the classical statistics for each
was chosen include prospect were reviewed. All prospects
a description of computer demonstrated log normal populations for
software and parameters gold. KKM, KW and GM were comprised of
used. a low-grade population (representing an
The availability of acceptable amount of internal waste),
check estimates, previous a medium-grade population (representing
estimates and/or mine the main mineralisation) and a small higher-grade
production records population. NZ and MK had similar low
and whether the Mineral and medium-grade populations, but had
Resource estimate larger high-grade populations, which had
takes appropriate been honoured in specific domains.
account of such data. Prior to undertaking the grade estimation,
The assumptions made all grade data was composited to a uniform
regarding recovery interval length. This was done to prevent
of by-products. potential grade bias in the estimations,
Estimation of deleterious from very long or short intervals. The
elements or other selected composite interval was 1 m, being
non-grade variables the most common sample length for each
of economic significance prospect. Composites were defined downhole,
(e.g. sulphur for with domain boundaries used as a constraint.
acid mine drainage Mean grades of composited and raw data
characterisation). were compared, no evidence of grade bias
In the case of block was observed due to compositing in KKM,
model interpolation, KW, NZ, and GM.
the block size in A review of composited data histograms
relation to the average for each domain suggested that the composite
sample spacing and grade populations were positively skewed
the search employed. and showed a broad range of gold grades,
Any assumptions behind including some extreme high-grade values
modelling of selective (outliers). The requirement to top cut
mining units. was informed by considering the coefficient
Any assumptions about of variation (COV) of gold at each prospect.
correlation between All prospects had a COV greater than 1
variables. (i.e a large spread of grades). Top cuts
Description of how were selected following a review of the
the geological interpretation gold histogram tail disintegration. A
was used to control review and consideration of the percentage
the resource estimates. of metal cut, percentage of data cut and
the resulting mean grade, ensured that
Discussion of basis the top cut applied was not overly severe.
for using or not using Data from the prospects, with the exception
grade cutting or capping. of MK were top cut. KW, GM, and NZ had
The process of validation, top cuts applied to all domain data. KKM
the checking process had a different top cut applied to Domain
used, the comparison 11, as it contained a higher grade population
of model data to drillhole relative to other domains. No top cut
data, and use of reconciliation was applied to MK prospect, due to the
data if available. effect of compositing on the dataset.
This essentially reduced the influence
of high-grade outliers prior to any compositing
step that would have been undertaken.
Separate block models were constructed
for each prospect using 25 m x 10 m x
10 m (E x N x RL) blocks. The parent block
size was chosen to honour current data
spacing and to be a multiple of potential
selective mining unit (SMU) size. Sub
cells were used to honour mineralisation
wireframe boundaries, although estimation
was into the larger parent cells.
Variography was undertaken for each prospect.
Upon completion of domain variography,
the resulting variogram models were cross
validated to assess their reliability.
This validation step was performed in
Micromine.
No assaying of deleterious elements was
done; therefore, it is not possible to
estimate these. Some amount of sulphide
should be expected, and acid mine drainage
studies should be undertaken as part of
future work.
Validation of each estimate was undertaken
to ensure that the grade and tonnage estimates
adequately honour the input data, and
that no significant or material bias in
grade or tonnage is introduced as a result
of the estimation process.
The following validations were undertaken
for each prospect:
* Global - A comparison of global input gold mean grade
vs global output gold mean grade, for each prospect.
On the whole output block model mean grades honoured
the average input mean grades.
* Local - A review of mean input grade and mean output
grade was undertaken on a domain-by-domain basis, for
each prospect. Smaller domains, where resource
volumes are relatively poorly informed by sample data,
exhibit less correlation than those that are better
informed. The main, more continuous domains, which
account for majority of the volume, have block model
grades that honour the input grades used in
estimation.
* Sectional review - Block models for all areas were
reviewed in 2D sections, so that block grade and
composite grade could be compared visually to ensure
that spatially, high-grade blocks correlate with
high-grade composite data, and vice versa.
* Swath plots - Swath plots were prepared for each
prospect. Composite data and block data were
displayed graphically by eastings, northings and RL
slices and compared. The block model grade
distribution honoured the distribution of input
composite grades throughout each model, with the
acceptance of some grade smoothing which was expected
when interpolating grade into blocks from discrete
samples.
--------------- -------------------------------- -------------------------------------------------------------
Moisture Whether the tonnages Tonnages were estimated dry and dry bulk
are estimated on a density was used for the estimation of
dry basis or with tonnages. No information on moisture content
natural moisture, was available.
and the method of
determination of the
moisture content.
--------------- -------------------------------- -------------------------------------------------------------
Cut-off The basis of the adopted A 0.5 g/t Au cut-off was applied for the
parameters cut-off grade(s) or reporting of Mineral Resources. The cut-off
quality parameters is in line with other similar, shallow
applied. gold deposits.
--------------- -------------------------------- -------------------------------------------------------------
Mining Assumptions made regarding The expected method of extraction would
factors possible mining methods, be by open pit mining. To demonstrate
or assumptions minimum mining dimensions reasonable prospects for eventual economic
and internal (or, extraction, conceptual pit shells were
if applicable, external) generated in Whittle software using the
mining dilution. It following parameters:
is always necessary * Mining cost: US$3/t
as part of the process
of determining reasonable
prospects for eventual * Processing cost: US$22/t ore
economic extraction
to consider potential
mining methods, but * Pit slope angle: 52deg
the assumptions made
regarding mining methods
and parameters when * Recovery: 90%
estimating Mineral
Resources may not
always be rigorous. * Royalty: 7%.
Where this is the
case, this should
be reported with an Mineral Resources were reported for mineralisation
explanation of the within these pit shells for each prospect.
basis of the mining
assumptions made.
--------------- -------------------------------- -------------------------------------------------------------
Metallurgical The basis for assumptions Red Rock undertook metallurgical test
factors or predictions regarding work for all prospects at the Migori Project
or assumptions metallurgical amenability. during 2012. Samples were sent to Wardell
It is always necessary Armstrong Mineral Processing Laboratories
as part of the process (Wardell), based in Cornwall in the UK.
of determining reasonable The results from all samples tested from
prospects for eventual NZ, KKM and KKM west, indicate a positive
economic extraction response to gold recovery by cyanide leaching,
to consider potential with further work is required to establish
metallurgical methods, the variable recovery trend evident in
but the assumptions the variability drill-core samples.
regarding metallurgical The test work results on the MK samples
treatment processes clearly demonstrate that the mineralisation
and parameters made is amenable to gold recovery by a modest
when reporting Mineral grind size followed by a cyanide leach
Resources may not in a mild strength cyanide solution at
always be rigorous. low lime consumption.
Where this is the The results from of the samples tested
case, this should from GM suggest a positive response to
be reported with an gold recovery by cyanide leaching for
explanation of the the oxide material, but low recoveries
basis of the metallurgical from the fresh material. The low recoveries
assumptions made. from the fresh material requires additional
test work to establish the reason for
this and a possible process treatment
route for additional recovery.
It appears most of the gold lost to tailings
is associated with sulphide mineralisation.
The sulphide content of each prospect,
and the ratio of gold to sulphur in the
individual samples should be evaluated
in the next phase of work.
The grind testwork appears to show that
the high-grade composites were much harder
and required more power input than the
low-grade samples. This is contrary to
expectations and will be reviewed during
the next phase of test work. Usually,
oxide samples show a lower power input
than for fresh material.
As testwork was only conducted on a single
composite of each style of mineralisation
for each deposit, the results should be
considered indicative that the material
is amenable to processing using conventional
extraction methods. More testwork is required
established a detailed processing flowsheet.
--------------- -------------------------------- -------------------------------------------------------------
Environmental Assumptions made regarding No environmental factors or assumptions
factors possible waste and were considered for the MRE.
or assumptions process residue disposal
options. It is always
necessary as part
of the process of
determining RPEEE
to consider the potential
environmental impacts
of the mining and
processing operation.
While at this stage
the determination
of potential environmental
impacts, particularly
for a greenfields
project, may not always
be well advanced,
the 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 Density determinations were done across
determined. If assumed, the project using the Archimedes method
the basis for the on drill core samples for oxide, transitional
assumptions. If determined, and fresh material.
the method used, whether Density data available by oxidation state
wet or dry, the frequency and prospect: Material type KW GM MK NZ
of the measurements, ---- --- ---- ----
the nature, size and Oxide 22 9 3 9
representativeness --------------- ---- --- ---- ----
of the samples. Transitional 37 19 5 34
The bulk density for --------------- ---- --- ---- ----
bulk material must Fresh 160 64 116 146
have been measured --------------- ---- --- ---- ----
by methods that adequately
account for void spaces The bulk density results were separated
(vugs, porosity, etc.), into prospect and material type. Mean
moisture and differences density values for each group were reviewed;
between rock and alteration the following observations were made:
zones within the deposit. Data populations for oxide and transitional
Discuss assumptions material were low, resulting in lower
for bulk density estimates confidence in the densities of these materials.
used in the evaluation * Oxide material had a lower density than transitional
process of the different and fresh material.
materials.
* Transitional material had a density that was similar
to the fresh material.
KW, MK, and GM material had very similar
density distributions and mean density
values for fresh material, KW and GM had
similar densities for all material types.
Due to the small data populations available
at MK for oxide and transitional material,
and the similarities in the density of
fresh material, the values for oxide and
transitional material for KW and GM were
applied to MK.
NZ had a different density distribution
and slightly higher mean density, which
has been attributed to the increased presence
of basalt in the stratigraphic package.
Further bulk density testing is required
to increase understanding of the bulk
density variability between oxidations
states, geological units, and mineralisation
styles.
Bulk density is expressed as dry density.
The density values are deemed reasonable
for the type of material under consideration.
Bulk density values as assigned to the
block models: Material KW, GM and NZ KKM
type MK
----------- ----- -----
Oxide 2.40 2.40 2.50
-------------- ----------- ----- -----
Transitional 2.75 2.90 2.72
-------------- ----------- ----- -----
Fresh 2.75 2.90 2.72
-------------- ----------- ----- -----
--------------- -------------------------------- -------------------------------------------------------------
Classification The basis for the Classification was reviewed on a prospect-by-prospect
classification of basis, taking the following points into
the Mineral Resources consideration:
into varying confidence * Data quality
categories.
Whether appropriate
account has been taken * Data spacing
of all relevant factors
(i.e. relative confidence
in tonnage/grade estimations, * The geological model
reliability of input
data, confidence in
continuity of geology * The continuity of mineralised domains, along-strike
and metal values, and down-dip
quality, quantity
and distribution of
the data). * The confidence in the grade estimate through
Whether the result consideration of kriging variance, (informed by the
appropriately reflects number of holes and samples used to estimate blocks)
the Competent Person's and the distances between data points and block
view of the deposit. centroid locations used to estimate grade for each
block.
These considerations are all informed
by the search pass (run) from which blocks
were estimated. The lower the run, the
better supported the estimated grade.
The validation of the estimates by means
of comparing statistics, visual comparison
of composite grades vs block grades and
swath plots also inform the confidence
in the estimate.
The classification reflects the Competent
Person's view of the deposit.
--------------- -------------------------------- -------------------------------------------------------------
Audits The results of any CSA Global reviewed the data supplied
or reviews audits or reviews by Red Rock which was used for the MRE.
of Mineral Resource The Competent Person reviewed the 2012
estimates. Mineral Resources which were used as the
basis for the 2021 Mineral Resource.
--------------- -------------------------------- -------------------------------------------------------------
Discussion Where appropriate The estimated block model was classified
of relative a statement of the to reflect the confidence in the Mineral
accuracy/ relative accuracy Resource. Areas classified as Indicated
confidence and confidence level have a reasonable level of confidence
in the MRE using an with regards to local estimates. Areas
approach or procedure classified as Inferred are considered
deemed appropriate global estimates.
by the Competent Person.
For example, the application
of statistical or
geostatistical procedures
to quantify the relative
accuracy of the resource
within stated confidence
limits, or, if such
an approach is not
deemed appropriate,
a qualitative discussion
of the factors that
could affect the relative
accuracy and confidence
of the estimate.
The statement should
specify whether it
relates to global
or local estimates,
and, if local, state
the relevant tonnages,
which should be relevant
to technical and economic
evaluation. Documentation
should include assumptions
made and the procedures
used.
These statements of
relative accuracy
and confidence of
the estimate should
be compared with production
data, where available.
--------------- -------------------------------- -------------------------------------------------------------
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