TIDMAURA
RNS Number : 8441P
Aura Energy Limited
14 February 2023
14 February 2023
Major Resource Upgrade at Aura Energy's Tiris Project
KEY POINTS:
* 52% increase in Measured and Indicated Resources to
29.6 Mlbs U(3) O(8) , 62.1Mt at 216 ppm U(3) O(8) at
a 100ppm grade cut-off.
* Global Mineral Resource Estimate (MRE) of 58.9 Mlbs
U(3) O(8,) 113Mt at 236 ppm U(3) O(8) at a 100ppm
grade cut-off.
* Near-term exploration targets identified to further
grow the Tiris resource.
* Tiris Reserves estimate with the updated expanded
Feasibility imminent
==================================================================
Aura Energy Limited (ASX: AEE, AIM: AURA) is pleased to announce
that the Resource Upgrade program undertaken in 2022 has increased
the Measured and Indicated (M&I) Resources at the Tiris Project
("Tiris or the "Project") from 19.5 Mlbs to 29.6 Mlbs, 62.2Mt at
216ppm U(3) O(8) at a 100ppm cut-off .
The significance of the Resource upgrade is that it enables Aura
to update the 2019 Tiris Definitive Feasibility Study (DFS) [1]
project work, assessing the potential to increase the production
rate based on the increased M&I resource. This work is expected
to be released before the end of Q1 2023.
Aura's Tiris Project differs from other near-term projects in
that the carnotite is mostly ultrafine, micron scale in grain size
enabling the separation of the uranium without crushing and
grinding as demonstrated in the 2019 DFS(1) . In the DFS(1)
production averaged 800,000 lbs U(3) O(8) per year with a capital
cost of USD 74.8 million and C1 costs of USD 25.43/lb U(3) O(8) .
Aura is confident that our existing fast-to-market development
strategy will be accentuated in the updated DFS as a result of the
economies of scale on the capital and operating costs using a
modular expansion of the Tiris Project.
Commenting on the increased MRE, Aura Energy Managing Director
Dave Woodall said:
"The significant increase of our M&I resources confirms our
confidence that the Tiris province which we believe has great
expansion potential. Our immediate focus is now to work with our
Mauritanian stakeholders, offtake providers, investors and
financing partners to progress towards a decision to Mine in Q3
CY2023, a target construction timeline of Q4 CY2023, and first
production expected in late 2024 or early 2025.
"Our exploration success is creating a strong platform for
growth for Aura's shareholders and our Mauritanian partners, and an
exciting new zero-carbon energy source for an increasingly
energy-hungry world."
Figure 1 - Location of the Tiris Project Global Mineral
Resource
Upgraded Measured and Indicated Resource
The program successfully delivered an additional Measured and
Indicated resource of 23.0Mt at 200ppm U(3) O(8) containing 10.1Mlb
U(3) O(8) at 100ppm U(3) O(8) cut-off grade. The detail of the
upgraded resource across the project areas and the previous
resources are shown in Tables 1 and 2. The drilling program
completed in 2022 comprised 1,746 holes (1,680 air-core and 66
diamond-core holes) at an average depth of 7m, from 11,600m of
drilling.
Mineral Resource Estimate Mineral Resource Estimate % Change
February 2022 [2] February 2023
==================== =============== ==================================
Resource Location Category Tonnes U(3) O(8) U(3) O(8) Tonnes U(3) O(8) U(3) O(8) Tonnes U(3) O(8)
(Mt) (ppm) (Mlbs) (Mt) (ppm) (Mlbs) (Mt) (Mlbs)
=============== ======== =========== =========== ======== =========== =========== ======== ===========
Hippolyte North Measured 5.7 225 2.8 8.0 236 4.2 40% 50%
=============== ======== =========== =========== ======== =========== =========== ======== ===========
Indicated 6.5 217 3.1 5.8 217 2.8 -11% -10%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Inferred 7.4 281 4.6 4.7 212 2.2 -36% -52%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Sub-Total 19.6 245 10.5 18.5 224 9.1 -6% -13%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Hippolyte Marie
& West Inferred 8.2 310.0 5.6 8.2 310 5.6 0% 0%
=============== ======== =========== =========== ======== =========== =========== ======== ===========
Hippolyte South Indicated 4.8 192 2.0 4.6 192 2.0 -4% 0%
=============== ======== =========== =========== ======== =========== =========== ======== ===========
Inferred 3.1 176 1.2 2.7 176 1.1 -13% -8%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Sub-Total 7.9 177 3.2 7.4 186 3.0 -6% -6%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Lazare North Measured 1.1 284 0.7 1.0 282 0.6 -9% -14%
=============== ======== =========== =========== ======== =========== =========== ======== ===========
Indicated 10.6 229 5.4 10.1 229 5.1 -5% -6%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Inferred 3.9 210 1.8 3.7 210 1.7 -5% -6%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Sub-Total 15.6 224 7.9 14.8 228 7.4 -5% -6%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Lazare South Measured 3.4 239 1.8 8.6 233 4.4 153% 144%
=============== ======== =========== =========== ======== =========== =========== ======== ===========
Indicated 2.6 219 1.3 5.2 226 2.6 100% 100%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Inferred 9.1 214 4.3 4.8 222 2.3 -47% -47%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Sub-Total 15.1 225 7.4 18.6 228 9.3 23% 26%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Sadi Measured 11.5 189 4.8
=============== ======== =========== =========== ======== =========== =========== ======== ===========
Indicated 4.5 240 2.4 7.4 200 3.2 64% 33%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Inferred 14.8 266 8.7 10.3 228 5.2 -30% -40%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Sub-Total 19.3 301 11.1 29.2 206 13.2 51% 19%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Total Tiris East
Resource Measured 10.2 235 5.3 29.1 218 14.0 185% 164%
=============== ======== =========== =========== ======== =========== =========== ======== ===========
Indicated 29.0 248 14.2 33.1 215 15.6 14% 10%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Inferred 46.5 254 26.2 34.5 237 18.0 -26% -31%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Total 85.7 242 45.7 96.6 224 47.7 13% 4%
==================================== ======== =========== =========== ======== =========== =========== ======== ===========
Oum Ferkik Resource Inferred 16.4 305 11.2 16.4 305 11.2 0% 0%
=============== ======== =========== =========== ======== =========== =========== ======== ===========
Total Tiris Project Resource 102.1 253 56.9 113.0 236 58.9 11% 4%
======== =========== =========== ======== =========== =========== ======== ===========
Table 1 - Comparison of Tiris Project Global Mine Resource
Estimate at 100ppm U(3) O(8) cut-off (3)
Tiris Uranium Project Summary
The Tiris Uranium Project is in North-eastern Mauritania (Figure
2), approximately 1,200km northeast of Nouakchott. Access is via
Zouérat, 744 km by bitumen road and then a further 700km on hardpan
desert roads. The MRE is based on drilling conducted on two Mineral
Exploration permits held 100% by Aura Energy: 562B4 Oum Ferkik,
2365B4 Oued EL Foule Sud, and on two Exploitation permits: 2492C4
Oued El Foule, 2491C4 Ain Sder held by Tiris Ressources SA (85%
Aura Energy). Oum Ferkik is under application for conversion to an
Exploitation Permit, with Oued EL Foule Sud under application for
renewal and is expected to be processed by Q2 2023.
Regional Geological Setting
The Tiris Uranium Project lies in the north-eastern part of the
Reguibat Craton, an Archaean (>2.5 Ga) and Lower Proterozoic
(1.6-2.5 Ga) aged complex composed principally of granitoids,
meta-sediments and meta-volcanics. The resources lie within
Proterozoic portions of the craton. This part of the craton
generally consists of intrusive and high-grade metamorphic rocks of
amphibolite facies grade. In addition to the Archaean and
Paleoproterozoic basement rocks, two principal types of Cainozoic
surficial sediments occur:
-- Hamada: sand and outwash fan material.
-- Cailloutis: flat lying calcrete layers, typically 1 to 3
metres thick, in places partially silicified, which in this area
stand out as small mesas up to a few metres above the surrounding
land surface.
Figure 2: Regional geology of Mauritania; red dots are Aura
uranium resources
Several small uranium occurrences were known in the Reguibat
Craton from exploration during the 1950's. These vein deposits such
as that at Bir En Nar, point to the existence of a poorly explored
uranium province. Economically significant calcrete-type uranium
deposits had not been reported in Mauritania prior to Aura's
discoveries.
All the resource zones lie beneath flat land surfaces covered by
surficial hamada and thin aeolian sand deposits. This shallow
overburden largely covers the basement rocks, which only appear as
scattered outcrops. Refer to Figure 4.
Figure 4 : Typical landscape within Tiris Project area, trench
illustrating soft sandy overburden with gravelly calcrete
beneath
Mineralisation
The uranium resources generally lie either within weathered,
partially decomposed red granite or in colluvial gravels developed
on or near red granites. Small portions occur in other rock types
such as meta-volcanics and meta-sediments. The resources are
believed to have developed within shallow depressions or basins,
where colluvial material has accumulated in desert sheet wash
events. The pebbles within the gravels are generally unweathered
fragments washed in from the nearby exfoliating granites and other
crystalline rocks, mixed with sand, silt, calcrete, gypsum and
yellow uranium vanadates.
This mineralised veneer of relatively unconsolidated material is
typically less than 5 metres in thickness, although locally it can
occur up to 12 metres in depth. It forms continuous deposits on the
plains or occurs in depressions amongst granite outcrops.
It is inferred that the deposits were formed by near-surface
leaching of uranium from the uraniferous red granites by saline
groundwaters during the wet Saharan "pluvial" periods. There have
been several periods over the past 2.5 million years, the most
recent ending only 5,900 years ago. Evaporation during the
subsequent arid periods caused the precipitation of uranium
vanadates, along with calcium, sodium and strontium carbonates,
sulphates and chlorides.
Although the Tiris mineralisation is associated with calcium
carbonates, it differs from other well-known calcrete uranium
deposits such as Langer Heinrich and Yeelirrie, in that they are
river valley-fill deposits. The Tiris deposits have formed in
shallow depressions in unconsolidated and uncemented gravels and in
partially decomposed granites. In Namibia and Western Australia,
the mineralisation is typically within calcareous clays or massive
hard calcrete which forms below the water table, often at several
levels related to the changing positions of the water table.
In contrast, Aura's Tiris deposits are believed to be pedogenic
calcrete occurrences that formed in the vadose zone by capillary
action above the permanent water table.
The host material at Tiris is granitic gravel or weathered
granite containing powdery calcium carbonate (calcrete) and
sulphates. The gravels and weathered granite occur at surface or
under a very thin (<30 cm) veneer of wind-blown sand and form
laterally continuous, single, thin sheets overlying fresh rock,
usually granite. This offers the opportunity for easy, low-cost
mining with little or no crushing.
The uranium mineralisation occurs principally as carnotite K(2)
(UO(2) )(2) (VO(4) )(2) .1-3H(2) O) and possibly some of the
chemically-similar calcium uranium vanadate, tyuyamunite Ca(UO(2)
)(2) (VO(4) )(2) .5-8H(2) O) in varying proportions. In this
report, "carnotite" refers to any mineral in the
carnotite-tyuyamunite series. The carnotite occurs as fine dustings
and coatings on granite or granite mineral fragments, and on the
surfaces or partly within the calcite cement that forms the patches
of calcrete. The carnotite is mostly ultrafine, micron scale in
grain size.
The carnotite is distributed erratically in numerous patches and
strings over short distances. Collectively it occurs in pods of
mineable size, some of which extend for several kilometres in a
horizontal direction.
Drilling techniques, hole spacing and mapping
Approximately 5,519 drill holes were used in this Resource
Estimate using predominantly air core drilling with diamond
drilling programs in 2017 and 2022 utilising triple tube PQ core
allowing grade estimation by both chemical analysis and downhole
gamma logging for validation purposes. In 3,113 (56%) of these,
U(3) O(8) grade was determined by downhole gamma logging with
disequilibrium factor applied, and in the remainder (44%), U(3)
O(8) grade was determined by chemical assay.
In most cases Measured Resources are based on 50m x 50m spaced
drill holes, Indicated Resources are based on 100m x 100m spaced
holes, and Inferred Resources on 100m x 200m spaced holes. For the
2022 drilling, the drill spacing for Measured Resources was
undertaken at 50m x 50m or 70m by 70m spacing. In 2017, three 100m
x 100m squares were drilled at 12.5m hole spacing in both N-S and
E-W directions to investigate grade anisotropy. In 2022, a further
two such detailed patterns were drilled. Variography constructed by
the resource consultants confirmed that the drill spacings are
appropriate for the Resource classifications.
The calcrete mineralisation is flat lying to sub-horizontal so
vertical holes were drilled, intersecting the mineralisation at a
high angle. The collars are spaced in a grid pattern to provide
adequate coverage of the mineralisation.
To account for solid outcrop in the resource statements,
geological outcrop mapping was undertaken in the field by Aura
Geologists for a portion of the work, and where field data was not
available the outcrop was digitised from Worldview 3-HD Satellite
Imagery to 15 cm resolution provided by Geoimage Pty Ltd. The
digitised shapes will be field checked in future field programs.
The inferred resource in Hippolyte Zones c, e, f, g was reported on
zero outcrop, and these will be updated in future reports.
Logging and Sampling.
For drilling programmes prior to 2017, all drilled material
provided by the AC rig was collected in its entirety in 1m
intervals except for the first metre which was sampled in 0.5m
intervals. All intervals were geologically logged.
For aircore drilling, AC drill cuttings were riffle split on
site to extract samples for assay, with the diamond drill core
lengths measured to an accuracy of 1 cm immediately on removal from
the core barrel to determine & record core recovery. After
transportation to the core yard in Nouakchott, the depths were
marked on the core at 1-metre intervals and recovery data was
checked again. Assays taken from the PQ core were compared against
downhole gamma information from the same hole. Table 1 in the
appendices contains all the information material to understand the
estimates of Mineral Resources.
For holes drilled from 2017 onwards, uranium concentrations were
measured by downhole total count gamma logging, which was converted
to equivalent uranium grades (eU(3) O(8) ) by applying calibration
information, an air correction and minor smoothing. A check was
undertaken on the disequilibrium between U238 and its
gamma-emitting daughter products. To test for radioactive
disequilibrium, 343 pulped-core samples were sent to Australian
Nuclear Science and Technology Organisation (ANSTO). Results were
compiled and interpreted by D Wilson of 3D Exploration.
Disequilibrium factors were produced in two different ways. The
first was based on laboratory measurements made at ANSTO, which
suggested a disequilibrium factor of 1.29. The second was a
comparison of drill core assay results against downhole gamma
logging which suggested a conversion factor of 1.16. When the
apparent underestimation of grade by ICP analysis (in comparison to
the more accurate DNA analysis) by 7% is taken into consideration
the drill hole assay data imply a conversion factor of 1.24. Aura
personnel decided a disequilibrium factor of 1.25 was appropriate
and applied this to convert raw gamma eU(3) O(8) grades to U(3)
O(8) grades.
Sample analysis and QAQC
Duplicates, blanks, and standards were inserted in the assay
sample stream at regular intervals. The drill core was cut in half
longitudinally by a diamond saw. For each half-metre of core,
half-core was bagged for assay. This task was completed in 2017 by
ALS Laboratories and in 2022 by MMM Laboratories in Nouakchott,
under the supervision of an Aura Geologist.
2011/12 AC drill samples were submitted to Stewart Laboratories
sample preparation facility near Zouérat in Mauritania. Samples
were crushed by jaw crusher to -12mm and 1kg was riffle split for
pulverising to +85% passing 75 microns. An 100g split was bagged
and sent to Stewart Laboratories in Ireland for analysis by pressed
pellet XRF. Previous analysis comparing different analytical
methods (XRF, ICP, DNC) had indicated that XRF is an accurate
method on this material, if an x-ray band is selected for
measurement that is not affected by the presence of strontium, and
this was done. This method will measure total uranium.
For the diamond core drilled in 2017, bagged 1/2 core was
prepared by ALS Laboratories Nouakchott by Method Prep 22 (Crush to
70% less than 6mm, pulverize entire sample to better than 85%
passing 75 microns). A 100g sample of pulp was split off using a
mini-riffle splitter. For diamond core drilled in 2022, sample
preparation was completed by MMM Laboratories in Nouakchott, using
the same method as for the 2017 core samples, except the 100g
sample of pulp was split off using rotary splitter. Sample pulps
were forwarded by air to ALS in Ireland for uranium analysis by ALS
Method U-MS62 (U by ICP-MS after four-acid digestion) which
provides near total extraction. ROL-21 agitation was carried out on
the pulps before selecting assay aliquot.
Downhole gamma logging was performed by 2 down-hole Auslog gamma
sondes utilising an A075 Natural Gamma Tool. Drill holes were gamma
logged as soon as possible after drilling to avoid radon build-up.
Each borehole was logged in both directions to verify consistency.
Logging speed was 2 metres per minute, with a sample interval of
1cm. At least one hole was re-logged after each 20 holes as a
repeatability check. A reference hole was established and relogged
every 2 days as a check on consistency. Gamma logging procedures
& interpretation were supervised by consultant David Wilson who
qualifies as a Competent Person in these matters.
QAQC procedures for the 2011/12 AC drilling involved submission
of 1 QAQC sample in every 5 samples, comprised of: field duplicates
every twelve samples, blanks every 31 samples, umpire assays every
11 samples, certified reference material every 129 samples. Umpire
analysis was carried on 427 sample intervals. For each of these the
original pressed pellet XRF sample assayed by Stewart Labs was
re-assayed by ICP by Stewart Labs. Each of these samples was also
assayed by XRF and by ICP by ALS Labs. Accuracy & precision
were within acceptable limits. QAQC procedures for the 2017 and
2022 diamond drilling comprise, submission of one standard, blank
and field duplicate every 25 samples. In each set of 25 samples, a
blank was inserted at every tenth position, standard at every
twentieth position and field duplicate every 25th position.
Accuracy & precision were within acceptable limits.
Estimation Methodology
The uranium resource estimates for the ore zones Hippolyte,
Hippolyte South, Lazare North, Lazare South and Sadi were conducted
by H&S Consultants (HSC). These estimates were based on a
combination of downhole radiometric logging and chemical analyses
of drillhole samples. This update incorporates recent infill
drilling completed during 2022 in three areas - Hippolyte North
Zone 3, Lazare South and Sadi - as well as updating existing (2018)
models for Lazare North and the rest of Hippolyte (North and South)
with recent digitising of outcrops from aerial photographs.
The uranium resource estimates for the ore zones Marie,
Hippolyte West, Oum Ferkik East, Oum Ferkik West deposits were
based on chemical analyses of drillhole samples. These estimates
were undertaken by Oliver Mapeto from Coffey Mining and
Associates.
Hippolyte North, Hippolyte South, Lazare North, Lazare South and
Sadi Resources determined by H&S Consultants Pty Ltd.
The Mineral Resources reported here occur in five separate areas
(Hippolyte North, Hippolyte South, Lazare North, Lazare South and
Sadi) within a rectangle around 32 km north-south and 42 km
east-west. The upper limit of the mineralisation occurs at surface
and the uranium mineralisation generally forms thin shallow
horizontal tabular bodies ranging in thickness from 1 to 12 m,
hosted in weathered granite and granitic sediments. Resources reach
a maximum depth of 14 m below surface. Differentiation of the
weathered granite from granitic sediments is unreliable from AC
sample returns. A purely geological model of the Tiris deposits has
not been produced. While the interpretation of the mineralisation
as flat lying tabular bodies is undisputed, alternative
interpretations of the geology are unlikely to significantly impact
estimated resources. The lateral extents of the mineralisation are
poorly defined and additional drilling around the edges of the
deposits may indicate that mineralisation is more limited than
currently interpreted.
HSC created surfaces representing the base of the estimates to
limit the extrapolation of grades into volumes that had no data.
This is important at Tiris as there is a general decrease in
uranium grades with depth. These surfaces nominally represent the
top of the less-weathered granite, where AC drilling could
penetrate no further. The base surfaces were produced using the
locations of the end of the deepest assay from each drill hole.
Where drill holes were very close, within around 15 m, the
shallower point was generally removed.
Areas of obvious outcrop were excised from the MRE assuming a
dip of 45 degrees between weathered granite/granitic sediments and
the less-weathered granite. The extent of outcrop/subcrop and its
relationship to free-digging mineralisation is somewhat uncertain
but a conservative approach has been taken to minimise this
risk.
The proportion of each block between the topographic and base
surfaces, as well as the proportion of outcrop, were assigned to
the block model and used to weight the reported estimates.
The continuity of both grade and geology are affected by the
extent of weathering of the granitic host and the distribution of
granitic sediments with respect to outcrop. The continuity does not
appear to be affected by faulting.
The uranium concentrations were estimated by recoverable
Multiple Indicator Kriging (MIK) using the GS3 geostatistical
software. The uranium grades at the Tiris deposits exhibit a
positively skewed distribution and therefore show reasonable
sensitivity to a small number of high grades. MIK is considered an
appropriate estimation method for the uranium grade distribution at
the Tiris deposits because it specifically accounts for the
changing spatial continuity at different grades through a set of
indicator variograms at a range of grade thresholds. It also
reduces the need to use the practice of top cutting. While no
top-cuts were applied, the average of the mean and median grades
was applied to the top indicator class to address any potential
extreme values.
Only U (3) O (8) was estimated. No assumptions were made
regarding the correlation of uranium with any other variable. No
deleterious elements or other non-grade variables of economic
significance were estimated. No assumptions were made regarding the
recovery of by-products. Uranium was assumed to be the only element
present in economically significant concentrations, although
vanadium is known to occur with the uranium in the main ore mineral
carnotite and could potentially be recovered.
All drill hole intervals were composited to 0.5m for
estimation.
The five deposits were subdivided into a number of subzones for
estimation, with conditional statistics generated for each of the
subzones. All class grades used for estimation of the mineralised
domains were derived from the class mean grades, except the top
indicator class. The Recoverable MIK technique employed by HSC in
this case requires a set of 14 variogram models, one for each of
the fourteen grade bins used. A set of variogram models were
created for Subzones of the Hippolyte North, Lazare South and Sadi
deposits. These variogram models were applied to Subzones that did
not have sufficient data to generate reliable models. Table 1, in
the appendices, in accordance with Listing Rule 5.8.1 contains all
information material to understand the estimates of Mineral
Resources.
All of the resources reported here have been estimated on the
assumption that the deposits will be mined by open pit.
Recoverable MIK allows for block support correction to account
for the change from sample size support to the size of a mining
block. This process requires an assumed grade control drill spacing
and the assumed size of the Selective Mining Unit (SMU). The
variance adjustment factors were estimated from the U (3) O (8)
metal variogram models assuming a minimum SMU of 10x10x0.5m (east,
north, vertical) with high quality grade control sampling on a
10x10x0.5m pattern (east, north, vertical).
The application of the variance adjustments to the resource
estimates is expected to provide estimates of recoverable resources
without the need to apply additional mining dilution or mining
recovery factors. Internal dilution, that is, within the SMU unit
is accounted for. If a larger SMU size or a broader grade control
drill pattern is implemented the selectivity assumed in the
reported resources may not be realised.
The 2023 Tiris Mineral Resource upgrade varies from the previous
mineral resource due to:
-- Additional drilling throughout the project area.
-- Geological outcrop mapping completed for all zone, excluding
Hippolyte Zones c, e, f, g and excised from the MRE assuming a dip
of 45 degrees between weathered granite/granitic sediments and the
less-weathered granite.
Hippolyte West, Oum Ferkik West and Oum Ferkik East Resources
determined by Oliver Mapeto (Coffey Mining).
Mineralisation forms flat lying tabular bodies ranging in
thickness from 1 to 12m with some internal waste patches occurring
within the mineralisation envelope. In places, the top of
mineralisation is covered by sand or waste overburden. Ore surfaces
representing the top and base of the mineralisation using a grade
cut-off of 100ppm U(3) O(8) were generated across all project areas
and mineralised zones. The top and base of ore surfaces were used
as hard boundaries to control grade estimation.
The grade varied significantly within the drill hole
intersections. In some zones, pods of low-grade mineralisation
occur showing moderate continuity of both grade and geology. The
mineralisation is recent and unaffected by faulting.
The Mineral Resource Estimates applied a lower a cut-off grade
of 100ppm across all project areas. The Marie ore zone occurs in an
area 1.2km east-west and 6km north-south. This region is comprised
of six separate zones that range in plan dimensions from 200m to
1.2km wide and 500m to 1.4km long. The Hippolyte W zone occurs in
an area 0.8km east-west and 2.0km north-south. This region is
comprised of three separate zones that range in plan dimensions
from 150m to 400m wide and 400m to 1.0km long. Oum Ferkik West
occurs as a single zone with dimensions of 1.6km east-west and
2.5km north-south. Oum Ferkik East occurs in an area 2.0km
east-west and 2.0km north-south. This region is comprised of six
separate zones that range in plan dimensions from 150m to 400m wide
and 400m to 1.2km long.
Uranium concentrations were estimated using the Ordinary Kriging
estimation method. The sample database has assay samples at a
nominal 1m sample interval. Some samples were sampled at 0.5m
interval using overburden-ore contact depending on thickness of
topsoil (sand). 2m sample composites were created for grade
estimation.
Area specific high-grade assay top cuts were applied to minimise
grade smearing. The top-cut values were chosen by assessing the
high-end distribution of the grade population within each zone and
selecting the value at which the distribution became erratic.
Each zone was divided into subzones for grade estimation. The
subzones were based on solids defined using a 100ppm lower U(3)
O(8) grade cut-off. In addition, upper cut-off grade specific to
the ore zones were applied. Each zone was coded and only samples
within the same matching zone code were used in estimation.
Additional estimation parameters were applied as follows:
A three-pass estimation strategy was adopted to estimate the U
(3) O (8) grades. The estimation search parameters are shown below
for estimation run pass 1, 2 and 3. The short first axis of the
search ellipse is vertical.
Pass 1. 300x200x6m search, 8-24 samples
Pass 2. 360x250x6m search, 6-24 samples
Pass 3. 600x400x6m search, 4-24 samples
Drill hole drill spacing is generally on a regular grid of
approximately 100x200 m. Parent block model size was 50 x 50x 2m.
Sub-block size 5 x 5 x 0.5m. The vertical dimension was chosen to
reflect the anisotropy of the mineralisation and the downhole data
spacing.
Block model grade estimates were validated using a statistical
comparison of block model grades against drill composite grades by
zone, visual check of cross sections, transverse, and long
sections, plan views of grade distribution, along with comparison
of block model and drill data grade distribution using
histograms.
The resources reported here have been estimated on the
assumption that the deposits will be mined by open pit mining
method. Analysis was done for grade continuity and variography.
However, in some cases, no reliable variogram structure could
defined on a zone-by-zone basis. The global variogram was assumed
as this could have been affected by lack of data due to limited
extend of the individual mineralised zones.
The selected sub-blocks were appropriate for minimum selective
mining unit.
The metallurgical test work information supplied to the
consultant is based on reports by H & S Consultants Pty Ltd,
which indicates that the Tiris deposits are amenable to a process
of crushing, screening and an alkaline carbonate leach in order to
recover uranium. Bench scale test work indicates that a significant
upgrade in uranium and decrease in sulphate concentrations can be
achieved through screening.
No deleterious elements or other non-grade variables of economic
significance have been identified or estimated.
Resource Classification
The relative accuracy and confidence level in the Mineral
Resource estimates are in line with the generally accepted accuracy
and confidence of the nominated JORC Mineral Resource categories.
This has been determined on a qualitative, rather than
quantitative, basis, and is based on the estimator's experience
with several deposits at NPM and similar deposits elsewhere. The
main factors that affect the relative accuracy and confidence of
the estimate are the drill hole spacing and the style of
mineralisation.
The Mineral Resource estimates for Marie, Hippolyte W, Oum
Ferkik West and Oum Ferkik East were based on drill hole drill grid
spacing, mineralisation and grade continuity, the grade estimation
search pass used to estimate the block. All mineral Resource
estimates estimated in 2011 were classified as Inferred. The
relative accuracy and confidence level in the Mineral Resource
estimates are in line with the generally accepted accuracy and
confidence of the nominated JORC CODE (2012) Mineral Resource
categories. This has been determined on both qualitative and
quantitative basis. The main factor that affects the relative
accuracy and confidence of the Mineral Resource estimate is sample
data density and high variability in uranium grades. Confidence in
mineralisation continuity is moderate. Most blocks were estimated
in estimation run Pass 1 and 2.
Bulk Density
Tonnages are estimated on a dry weight basis. The moisture
constant was not determined. Dry bulk density of diamond drill core
was measured at the ALS facility in Nouakchott using an immersion
method (Archimedes principle) on selected PQ diamond drill core
intervals ranging in size from 10 to 30cm. Competent pieces of
drill core were selected on a nominal interval of 50cm. The samples
chosen are believed to be representative of the surrounding rock
type. All density samples are wrapped in cling film to avoid water
absorption. A total of 412 density measurements have been taken
from drill core at the Tiris deposits with values ranging from 1.50
to 2.66t/m (3) and averaging 2.13t/m (3) . Measured density values
show that there is a reasonable correlation between density and the
depth of the sample. A regression was used to assign densities to
each block in the block model based on the depth below surface.
The Mineral Resource estimates for Marie, Hippolyte W, Oum
Ferkik West and Oum Ferkik East used an average density of 2.0/g/cc
dry bulk density based on tests done by Aura Energy. This was
considered realistic for material and ore in similar ore deposits.
Tonnages are estimated on a dry weight basis. The moisture constant
was not determined.
Cut-Off Grade
A cut-off of 100ppm U (3) O (8) cut off is used to report the
resources as it is assumed that ore can be economically mined at
this grade in an open pit scenario. This cut-off is relatively low
compared to operating uranium mines, but metallurgical test work
indicates that a significant upgrade in uranium and decrease in
sulphates can be achieved by a simple screening process.
This ASX Release is authorised by the Aura Energy Board of
Directors.
The information contained within this announcement is deemed by
the Company to constitute inside information as stipulated under
the Market Abuse Regulations (EU) No. 596/2014 ('MAR') which has
been incorporated into UK law by the European Union (Withdrawal)
Act 2018. Upon the publication of this announcement via Regulatory
Information Service ('RIS'), this inside information is now
considered to be in the public domain.
For further information, please contact:
David Woodall Paul Ryan
Managing Director and CEO Citadel-MAGNUS
Aura Energy Limited Investor & Media Relations
info@auraenergy.com.au pryan@citadelmagnus.com
+61 409 296 511
SP Angel Corporate Finance LLP WH Ireland Limited
(Nominated Advisor and Joint Broker) (Joint Broker)
David Hignell Jessica Cave
Kasia Brzozowska Andrew de Andrade
+44 (0) 203 470 0470 +44 (0) 207 220 1666
----------------------------
About Aura Energy (ASX: AEE, AIM AURA)
Aura Energy is an Australian-based minerals company that has
major uranium and polymetallic projects with large resources in
Africa and Europe. The Company is now focused on uranium production
from the Tiris Project, a major greenfields uranium discovery in
Mauritania.
Aura also completed a capital estimate update for the Tiris
Definitive Feasibility Study, to reflect current global pricing,
with these 2021 figures reconfirming Tiris as one of the lowest
capex, lowest operating cost uranium projects.
In October 2021, the Company entered a US$10m Offtake Financing
Agreement with Curzon, which includes an additional up to US$10m
facility, bringing the maximum available under the agreement to
US$20m.
In 2022, Aura will continue to transition from a uranium
explorer to a uranium producer, to capitalise on the rapidly
growing demand for nuclear power as the world continues to shift
towards a decarbonised energy sector.
Disclaimer Regarding Forward-Looking Statements
This ASX announcement (Announcement) contains various
forward-looking statements. All statements other than statements of
historical fact are forward-looking statements. Forward-looking
statements are inherently subject to uncertainties in that they may
be affected by a variety of known and unknown risks, variables and
factors which could cause actual values or results, performance, or
achievements to differ materially from the expectations described
in such forward-looking statements. The Company does not give any
assurance that the anticipated results, performance, or
achievements expressed or implied in those forward-looking
statements will be achieved.
Notes to Project Description
The Company confirms that the material assumptions underpinning
the Tiris Uranium Production Target and the associated financial
information derived from the Tiris production target as outlined in
the Aura Energy release dated 18 August 2021 for the Tiris Uranium
Project Definitive Feasibility Study continue to apply and have not
materially changed.
The Company confirms that it is not aware of any new information
or data that materially affects the information included in the
relevant market announcement and that all material assumptions and
technical parameters underpinning the estimates in the relevant
market announcements continue to apply and have not materially
changed.
Concerning the Resource statements, there is a low level of
geological confidence associated with the inferred mineral resource
and there is no certainty that further exploration work will result
in the determination of indicated measured resource or that the
production target will be realised.
Competent Persons
The Competent Person for the portion of the 2023 Tiris Mineral
Resource Estimate and classification relating to the Hippolyte,
Hippolyte South, Lazare North, Lazare South and Sadi deposits is Mr
Arnold van der Heyden of H&S Consulting Pty Ltd. The
information in the report to which this statement is attached that
relates to the 2023 Mineral Resource Estimate is based on
information compiled by Mr van der Heyden. Mr van der Heyden has
sufficient experience that is relevant to the resource estimation
to qualify Mr van der Heyden as a Competent Person as defined in
the 2012 edition of the 'Australasian Code for Reporting of
Exploration Results, Mineral Resources and Ore Reserves'. Mr van
der Heyden is an employee of H&S Consultants Pty Ltd, a Sydney
based geological consulting firm. Mr van der Heyden is a Member and
Chartered Professional of The Australasian Institute of Mining and
Metallurgy (AusIMM) and consents to the inclusion in the report of
the matters based on his information in the form and context in
which it appears.
The Competent Person for the portion of the 2023 Tiris Vanadium
Resource Estimate and classification relating to all other deposits
within the resource (Marie, Hippolyte West, Oum Ferkik East, Oum
Ferkik West deposits) is Mr Oliver Mapeto, an independent resources
consultant. The information in the report to which this statement
is attached that relates to the 2018 Resource Estimate is based on
information compiled by Mr Mapeto. Mr Mapeto has sufficient
experience that is relevant to the resource estimation to qualify
Mr Mapeto as a Competent Person as defined in the 2012 edition of
the 'Australasian Code for Reporting of Exploration Results,
Mineral Resources and Ore Reserves'. Mr Mapeto is a Member of The
Australasian Institute of Mining and Metallurgy (AusIMM) and
consents to the inclusion in the report of the matters based on his
information in the form and context in which it appears.
The Competent Person for drill hole data and for integrating the
different resource estimates prior to September 2022 is Mr Neil
Clifford. The information in the report to which this statement is
attached that relates to compiling resource estimates and to drill
hole data is based on information compiled by Mr Neil Clifford. Mr
Clifford has sufficient experience that is relevant to the style of
mineralisation and type of deposit under consideration and to the
activity which he is undertaking to qualify Mr Clifford as a
Competent Person as defined in the 2012 edition of the
'Australasian Code for Reporting of Exploration Results, Mineral
Resources and Ore Reserves'. Mr Clifford is a consultant to Aura
Energy. Mr Clifford is a Member of the Australasian Institute of
Geoscientists. Mr Clifford consents to the inclusion in the report
of the matters based on his information in the form and context in
which it appears.
The Competent Person for drill hole data and for integrating the
different resource estimates from September 2022 is Dr Michael
Fletcher. The information in the report to which this statement is
attached that relates to compiling resource estimates and to drill
hole data is based on information compiled by Dr Michael Fletcher.
Dr Fletcher has sufficient relevant experience in the preparation
and compilation of exploration data across a broad range of
deposits 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'. Dr Fletcher is a
consultant to Aura Energy and a full-time employee of GeoEndeavours
Pty Ltd. Dr Fletcher is a Member of the Australasian Institute of
Geoscientists and consents to the inclusion in the report of the
matters based on his information in the form and context in which
it appears.
The Competent Person for interpreting downhole gamma
information, disequilibrium analysis and assay results is Mr David
Wilson. Mr Wilson has sufficient experience that is relevant to the
style of mineralisation and type of deposit under consideration and
to the activity which 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'. Mr Wilson is a consultant to Aura Energy and is a
full-time employee of 3D Exploration. Mr Wilson is a Member of the
Australasian Institute of Geoscientists and consents to the
inclusion in the report of the matters based on his information in
the form and context in which it appears.
APPIX 1
JORC Code 2012
Table 1 Appendix 5A ASX Listing Rules
2023 Tiris Vanadium Resource Estimate
Section 1 Sampling Techniques and Data
(Criteria in this section apply to all succeeding sections)
Criteria JORC Code explanation Commentary
===========================================================================
Sampling
techniques * Nature and quality of sampling (e.g. cut channels, -- The data on which this resource
random chips, or specific specialised industry estimate is based is from 6
standard measurement tools appropriate to the field sampling programs:
minerals under investigation, such as down hole gamma 1. An air-core (AC) drilling
sondes, or handheld XRF instruments, etc). These program in 2010/11 with grade
examples should not be taken as limiting the broad estimation by chemical analysis
meaning of sampling. of drill samples
2. An AC drilling program at
Lazare in 2012 with grade estimation
* Include reference to measures taken to ensure sample by chemical analysis of drill
representivity and the appropriate calibration of any samples
measurement tools or systems used. 3. An AC drilling program at
Sadi in 2015 with grade estimation
by chemical analysis of drill
* Aspects of the determination of mineralisation that samples
are Material to the Public Report. 4. An AC drilling program in
2017 with grade estimation by
downhole gamma logging
* In cases where 'industry standard' work has been done 5. An AC drilling program in
this would be relatively simple (e.g. 'reverse 2022 with grade estimation by
circulation drilling was used to obtain 1 m samples downhole gamma logging
from which 3 kg was pulverised to produce a 30 g 6. Diamond drilling (DD) programs
charge for fire assay'). In other cases, more in 2017 and 2022 with grade
explanation may be required, such as where there is estimation by both chemical
coarse gold that has inherent sampling problems. analysis of core and by downhole
Unusual commodities or mineralisation types (eg gamma logging, for validation
submarine nodules) may warrant disclosure of detailed purposes.
information. -- The 2011/12 drilling was
the basis of 2 previous Resource
Estimation exercises (ASX release:
announcement 14 July 2011 "First
Uranium Resource in Mauritania
- 50 million pounds", & ASX
release: 16 July 2014 "Reguibat
Uranium Project Scoping Study
Complete). The 2018 resource
estimation exercise has been
aimed at upgrading a substantial
portion of Inferred Resource
to a higher resource category.
-- The 2011/12 drillhole spacing
was predominantly 100m x 200m.
A portion of the 2012 drilling
was at a spacing of 50m x 100m
drilled to define Indicated
Resources. The 2017 drilling
was predominantly at a spacing
of 50m x 50m to define Measured
Resources.
-- AC drill cuttings were riffle
split on site to extract approx.
2 kg samples for assay for the
downhole intervals 0 to 0.5m,
0.5 to 1.0m, 1 to 2m, & thereafter
in 1m intervals to end of hole.
-- Down hole gamma logging in
2017 and 2022 was by 2 down-hole
Auslog gamma sondes operated
by Poseidon Geophysics (Pty)
Ltd based in Gaborone Botswana
using 3 geophysicists employed
by Poseidon geophysics
-- The 2 sondes (serial numbers
T093 and T272) were sent to
the Department of Environment,
Water & Natural Resources, Adelaide
South Australia for calibration
prior to the surveys in both
2017 and 2022.
-- Geological outcrop mapping
was undertaken in the field
by Aura Geologists for a portion
of the work, and where field
data was not available the outcrop
was digitised from Worldview
3-HD Satellite Imagery to 15
cm resolution provided by Geoimage
Pty Ltd. The digitised shapes
will be field checked in future
field programs. The inferred
resource in Hippolyte Zones
c, e, f, g still need to be
digitised.
Drilling -- AC drilling in all programs
techniques * Drill type (eg core, reverse circulation, open-hole prior to 2022 was conducted
hammer, rotary air blast, auger, Bangka, sonic, etc) by Wallis Drilling of Perth
and details (eg core diameter, triple or standard WA using a Mantis drillrig with
tube, depth of diamond tails, face-sampling bit or NQ size bit (outer diameter
other type, whether core is oriented and if so, by 75.7 mm) except for the 2015
what method, etc). program which used HQ size bit
(OD 96mm). Diamond drilling
(DD) was carried out by Capital
Drilling Mauritanie SARL utilising
triple tube PQ coring (122.6
mm outer diameter bit, 85 mm
diameter core). In 2017, 1484
vertical drillholes were gamma
logged of which 1428 were AC
drillholes and 56 were cored
diamond drillholes.
-- In 2022, AC drilling was
conducted by Sahara Natural
Resources (Guinea) using a 650
model DTH cum-rotary rig. PQ
triple-tube diamond drilling
was conducted by Tayssir Drilling
1742 vertical drillholes were
gamma logged of which 1676 were
AC holes and 66 were cored diamond
holes.
Drill sample -- For the 2010, 2011, 2012
recovery * Method of recording and assessing core and chip Aircore programs, no sample
sample recoveries and results assessed. recovery information is available.
-- 2015 AC drilling the total
drill return for each sample
* Measures taken to maximise sample recovery and ensure interval was bagged and weighed
representative nature of the samples. to an accuracy of approximately
0.25 kg to estimate sample recovery.
The assay results for the 2015
* Whether a relationship exists between sample recovery drilling are considered inaccurate
and grade and whether sample bias may have occurred due to loss of fine uranium-bearing
due to preferential loss/gain of fine/coarse carnotite during the drilling
material. process, on the basis of 63
holes which were later gamma
logged which indicated that
eU3O8 grades were approx. 3
times greater than assay grades
Since 2015, 35% (205) of the
2015 collars had another hole
drilled within 15 metres and
a downhole gamma survey undertaken.
-- Efforts were made to minimise
dust loss, eg in most holes
the first metre was drilled
without applying compressed
air, and thereafter minimum
air necessary to lift the sample
was applied. In view of the
ultrafine grain size of the
uranium mineral carnotite, even
where high recoveries were recorded,
it is possible that some carnotite
was lost in dust emitted from
the drill rig cyclone. resulting
in underestimation of uranium
grade
-- 2017 and 2022 AC drillholes
were not physically sampled,
and downhole gamma surveys were
completed for grade measurement.
-- All drillcore was transported
in covered core trays to Nouakchott
for geological logging, density
determination, and core cutting.
-- Drillcore lengths were measured
to an accuracy of c. 1 cm immediately
on removal from the core barrel
to determine & record core recovery.
After transportation to the
core yard in Noakchott, the
depths were marked on the core
at 1 metre intervals and recovery
data was checked again. 81%
of core samples have a recovery
of 95% or greater, and 85% of
core samples have a recovery
of 90% or greater.
-- Given the ultra-fine-grained
nature of the carnotite mineralisation,
loss of uranium is likely in
any core runs recording less
than 100% recovery, and even
where 100% recovery is recorded
it is possible some loss of
carnotite may have occurred.
Logging
* Whether core and chip samples have been geologically * In 2011/12/15 AC drilling each sample interval was
and geotechnically logged to a level of detail to geologically logged by an onsite geologist and drill
support appropriate Mineral Resource estimation, logs were uploaded to Aura's database managed by
mining studies and metallurgical studies. Reflex Hub in Perth. A sample of sieved & washed
chips for each sample interval was retained in chip
trays for reference. In 2017 and 2022 AC drilling.
* Whether logging is qualitative or quantitative in only the bottom hole sample was geologically logged,
nature. Core (or costean, channel, etc) photography. and a sample retained in chip trays.
* The total length and percentage of the relevant * Drillcore was photographed, geologically logged and
intersections logged. logs were recorded on Aura's logging template and
uploaded to Aura's database.
* In 2011/12/17 drilling, 385 density measurements
(which included 25 duplicate determinations) were
taken on drillcore by ALS Laboratories in Nouakchott
under the supervision of Aura's geologist. In 2022,
174 density measurements were taken on drill core by
MMM Laboratories SARL in Noakchott, under the
supervision of an Aura Geologist.
* Database management was undertaken by Reflex Hub in
Perth prior to July 2019, and by Earth SQL in
Melbourne after that date.
Sub-sampling
techniques * If core, whether cut or sawn and whether quarter, * 2011/12/15 AC drill samples were riffle split on site
and sample half or all core taken. to provide a minimum 2 kg sample for assay and a
preparation duplicate split for reference and possible umpire
analysis.
* If non-core, whether riffled, tube sampled, rotary
split, etc and whether sampled wet or dry.
* Duplicates, blanks, and standards were inserted in
the assay sample stream at regular intervals as
* For all sample types, the nature, quality and detailed in the next section.
appropriateness of the sample preparation technique.
* Drillcore from 2017 was cut in half longitudinally by
* Quality control procedures adopted for all diamond saw by ALS Laboratories after marking up by,
sub-sampling stages to maximise representivity of and under the supervision of, an Aura geologist. This
samples. task was completed in 2022 by MMM Laboratories in
Noakchott, under the supervision of an Aura
Geologist.
* Measures taken to ensure that the sampling is
representative of the in-situ material collected,
including for instance results for field * For each half-metre of core, half-core was bagged for
duplicate/second-half sampling. assay.
* Whether sample sizes are appropriate to the grain * Given the fine-grained nature of the uranium minerals
size of the material being sampled. these sample sizes are appropriate.
Quality
of assay * The nature, quality and appropriateness of the * 2011/12 AC drill samples were submitted to Stewart
data and assaying and laboratory procedures used and whether Laboratories sample preparation facility near
laboratory the technique is considered partial or total. Zouérat in Mauritania (In 2012 Stewart
tests Laboratories became part of ALS Laboratories).
Samples were crushed by jaw crusher to -12mm and 1kg
* For geophysical tools, spectrometers, handheld XRF was riffle split for pulverising to +85% passing 75
instruments, etc, the parameters used in determining microns. An c. 100g split was bagged and sent to
the analysis including instrument make and model, Stewart Laboratories in Ireland for analysis by
reading times, calibrations factors applied and their pressed pellet XRF. Previous analysis comparing
derivation, etc. different analytical methods (XRF, ICP, DNC) had
indicated that XRF is an accurate method on this
material, if an x-ray band is selected for
* Nature of quality control procedures adopted (eg measurement that is not affected by the presence of
standards, blanks, duplicates, external laboratory strontium, and this was done. This method will
checks) and whether acceptable levels of accuracy measure total uranium. 2015 AC drill samples were
(i.e. lack of bias) and precision have been submitted to ALS Laboratories sample preparation
established. facility in Nouakchott Mauritania. Samples were
crushed by jaw crusher to -12mm and 1kg was riffle
split for pulverising to +85% passing 75 microns. An
c. 100g split was bagged and sent to ALS Global in
Ireland for analysis by ALS method MC-ICP61 after
4-acid digestion. This method will measure near total
uranium.
* For diamond core drilled in 2017, bagged 1/2 core was
prepared by ALS Laboratories Nouakchott by Method
Prep 22 (Crush to 70% less than 6mm, pulverize entire
sample to better than 85% passing 75 microns). An c.
100g sample of pulp was split off using mini-riffle
splitter, placed in sample envelope and forwarded by
air to ALS in Ireland for uranium analysis by ALS
Method U-MS62 (U by ICP-MS after 4 acid digestion). 4
acid digestion provides near total extraction.
* For diamond core drilled in 2022, sample preparation
was completed by MMM Laboratories in Noakchott.
Samples were crushed to 70% less than 6mm, pulverize
entire sample to better than 85% passing 75 microns.
An c. 100g sample of pulp was split off using rotary
splitter, placed in sample envelope and forwarded by
air to ALS in Ireland for uranium analysis by ALS
Method U-MS62 (U by ICP-MS after 4 acid digestion).
ROL-21 agitation was carried out on the pulps before
selecting assay aliquot. 4 acid digestion provides
near total extraction.
* Downhole gamma logging was performed by 2 down-hole
Auslog gamma sondes comprising:
* DLS5 Winch Controller
* W600-1 12V Portable Winch
* A075 Natural Gamma Tool
* Logging procedures involved:
* Drill holes were gamma logged as soon as possible
after drilling to avoid radon build-up.
* Each borehole logged in both directions to verify
consistency.
* Logging speed: 2 metres per minute
* Sampling interval: 1 cm
* At least one hole was re-logged after each 20 holes
as a repeatability check.
* A reference hole was established and relogged every 2
days as a check on consistency.
* Gamma logging procedures & interpretation were
supervised by consultant David Wilson who qualifies
as a Competent Person in these matters.
* QAQC procedures for the 2011/12 AC drilling comprised,
on average:
* Field duplicates assays: 1 in every 12 samples
* Blanks: 1 in every 31 samples
* Umpire assays: 1 in every 11 samples Umpire analysis
was carried on 427 sample intervals. For each of
these the original pressed pellet XRF sample assayed
by Stewart Labs was re-assayed by ICP by Stewart
Labs. Each of these samples was also assayed by XRF
and by ICP by ALS Labs.
* Certified Reference material: 1 in every 129 samples
* Total QAQC samples: 1 in every 5 samples
Accuracy & precision were within
acceptable limits.
* QAQC procedures for the 2017 and 2022 diamond
drilling comprise, submission of one standard, blank
and field duplicate every 25 samples. In each set of
25 samples, a blank was inserted at every tenth
position, standard at every twentieth position and
field duplicate every 25(th) position.
* 190 sample pulps sent to ANSTO Minerals at Lucas
Heights for U determination by Delayed Neutron Count,
serving as the Umpire analysis.
* Certified reference standards at 128, 264, and 550
ppm were purchased from African Mineral Standards,
South Africa. Blanks were prepared from sand
collected near the University of Noakchott, that had
been scanned with a hand-held spectrometer.
Verification -- Approximately 5519 drillholes
of sampling * The verification of significant intersections by were used in this Resource Estimate.
and assaying either independent or alternative company personnel. In 3113 56%) of these, U grade
was determined by downhole gamma
logging, and in the remainder
* The use of twinned holes. (44%), U grade was determined
by chemical assay. Diamond drillholes
were both gamma logged and chemically
* Documentation of primary data, data entry procedures, assayed for validation purposes.
data verification, data storage (physical and The holes drilled in 2015 were
electronic) protocols. excluded from the resource estimate.
-- To test for radioactive disequilibrium
343 samples were sent to Australian
* Discuss any adjustment to assay data. Nuclear Science and Technology
Organisation (ANSTO) in Australia
for equilibrium determinations.
Results were compiled and interpreted
by D Wilson of 3D Exploration.
Disequilibrium factors were
produced in two different ways.
The first was based on laboratory
measurements made at ANSTO,
which suggested a disequilibrium
factor of 1.29. The second was
comparison of drill core assay
results against downhole gamma
logging which suggested a conversion
factor of 1.16. When the apparent
under estimation of grade by
ICP analysis (in comparison
to the more accurate DNA analysis)
by 7% is taken into consideration
the drill hole assay data imply
a conversion factor of 1.24.
Aura personnel decided a disequilibrium
factor of 1.25 was appropriate
and applied this to convert
eU3O8 grades to U3O8 grades.
A factor of 1.25 needs to be
applied to all raw gamma grades
to provide the correct U grade.
All drillhole data recorded
was uploaded to Aura's online
database managed by Reflex Hub
during the programs prior to
July 2019 and managed by Earth
SQL after that date. Analyses
were forwarded directly from
the laboratories to the database
manager for incorporation in
the database.
Location -- 2011/12 drillhole collars
of data * Accuracy and quality of surveys used to locate drill were surveyed by handheld GPS
points holes (collar and down-hole surveys), trenches, mine with reported accuracy of +/-
workings and other locations used in Mineral Resource 3 metres.
estimation. -- All 2017 and 2022 drillhole
collars were surveyed by differential
surveying conducted by IRC-Magma
* Specification of the grid system used. (ISO 9001-2015) to an accuracy
of +/- 20 cm in all dimensions.
-- The grid projection used
* Quality and adequacy of topographic control. is UTM WGS84 Zone 29N.
-- An independent check comparing
data gathered prior to 2022
to topography was undertaken
by PhotoSat of Vancouver, using
satellite data provided to an
accuracy of +/- 20 cm, confirming
the quality and adequacy of
topographic control.
Data spacing -- Drillholes were spaced in
and * Data spacing for reporting of Exploration Results. different programs at 50m x
distribution 50m, 50m x 100m, 100m x 100m
or 100m x 200m.
* Whether the data spacing, and distribution is -- In most cases Measured Resources
sufficient to establish the degree of geological and are based on 50m x 50m spaced
grade continuity appropriate for the Mineral Resource drillholes, Indicated Resources
and Ore Reserve estimation procedure(s) and are based on 100m x 100m spaced
classifications applied. holes, and Inferred Resources
on 100m x 200m spaced holes.
-- Downhole gamma data was composited
* Whether sample compositing has been applied. into 0.5m intervals.
-- Three 100m x 100m areas were
drilled at 12.5m spacing in
both N-S & E-W directions for
geostatistical purposes and
to examine variability. Variography
constructed by the resource
consultants confirmed that the
drill spacings are appropriate
for the Resource classifications.
Resource classification was
done by the independent resource
consultants with no input from
Aura.
-- For the 2022 drilling, the
drill spacing for Measured Resources
was undertaken at 50m x 50m
or 70 by 70 metre spacing.
Orientation -- In 2017, three 100m x 100m
of data * Whether the orientation of sampling achieves unbiased squares were drilled at 12.5m
in relation sampling of possible structures and the extent to hole spacing in both N-S and
to which this is known, considering the deposit type. E-W directions to investigate
geological grade anisotropy. This indicated
structure a weak NW-SE trend to the mineralisation.
* If the relationship between the drilling orientation The drilling pattern employed
and the orientation of key mineralised structures is is considered appropriate for
considered to have introduced a sampling bias, this the mineralisation orientation.
should be assessed and reported if material. In 2022, a further two such
detailed patterns were drilled.
-- The calcrete mineralisation
is flat lying to sub-horizontal
so vertical holes were drilled,
intersecting the mineralisation
at a high angle.
-- The collars are spaced in
a grid pattern so provide adequate
coverage of the mineralisation,
demonstrating a broad NW_SE
linearity to the mineralisation.
Sample -- Sample collection was supervised
security * The measures taken to ensure sample security. by geologists. Samples were
transported as soon as practicable
to independent sample preparation
facilities.
-- The core samples were transported
to the processing facility in
Noakchott where they were logged,
and sample selection was undertaken
by geologists. The core trays
were then transported to MMM
laboratories in Noakchott for
cutting, sampling and sample
preparation. The pulped samples
were sent to ALS Ireland for
analysis.
-- Approx.67% of drillholes
were assayed by downhole gamma
logging and for these, sample
security is not relevant.
Audits -- Resource estimation in 2012
or reviews * The results of any audits or reviews of sampling was conducted by Oliver Mapeto
techniques and data. of Coffey Mining. This was independently
reviewed and confirmed by Wardell
Armstrong International in 2016.
The 2021 Resource Estimate at
Sadi was done by Oliver Mapeto
acting then as an independent
consultant. The 2018 resource
estimate, and the 2023 Resource
Estimate have been carried out
by independent consulting group
H&S Consultants Pty Ltd. All
of these consulting groups have
reviewed and endorsed the sampling,
grade estimation and QAQC procedures.
============= ============================================================ ================================================================
Section 2 Reporting of Exploration Results
(Criteria listed in the preceding section also apply to this
section)
Criteria JORC Code explanation Commentary
===============================================================
Mineral -- The Resource Estimates
tenement * Type, reference name/number, location and ownership are based on drilling conducted
and land including agreements or material issues with third on 2 mineral exploration permits
tenure status parties such as joint ventures, partnerships, held 100% by Aura Energy:
overriding royalties, native title interests, 562B4 Oum Ferkik, 2365B4 Oued
historical sites, wilderness or national park and EL Foule Sud, and on 2 Exploitation
environmental settings. permits: 2492C4 Oued El Foule,
2491C4 Ain Sder held by Tiris
Ressources SA. Oued EL Foule
* The security of the tenure held at the time of Sud is currently under application
reporting along with any known impediments to for renewal. Tiris Ressources
obtaining a licence to operate in the area. SA is owned 85% by Aura Energy
subsidiary, Aura Energy Mauritania
and 15% by ANARPAM, a Mauritanian
Government entity.
-- Aura has completed an Environmental
and Social Impact Assessment
which concluded there are
no known issues arising from
native title, historical sites,
environmental or third-party
matters which are likely to
materially affect exploitation.
Exploration -- Aura is unaware of any
done by * Acknowledgment and appraisal of exploration by other prior exploration on these
other parties parties. areas, other than governmental
data gathering projects such
as the PRISM-II Mauritania
Minerals Project (USGS)
Geology -- The mineralisation is of
* Deposit type, geological setting and style of the calcrete uranium style.
mineralisation. It occurs within Proterozoic
rocks of the Reguibat Craton.
The mineralisation is developed
within near surface altered
and weathered granites, and
within shallow colluvium lying
on granite or adjacent metasediments.
Drill hole -- Specific drillhole data
Information * A summary of all information material to the is not relevant to the reporting
understanding of the exploration results including a of this resource estimation
tabulation of the following information for all because the topography is
Material drill holes: not significantly variable,
and all holes are vertical,
drilled almost perpendicular
1. easting and northing to sub-horizontal mineralisation
of the drill hole collar at depth of less than 10 metres.
2. elevation or RL (Reduced
Level - elevation above
sea level in metres) of
the drill hole collar
3. dip and azimuth of
the hole
4. down hole length and
interception depth
5. 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 * In reporting Exploration Results, weighting averaging * Data aggregation methods are summarised in the
methods techniques, maximum and/or minimum grade truncations Resource Estimate report by H&S Consultants which
(eg cutting of high grades) and cut-off grades are this table accompanies.
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 -- All drillholes on which
between * These relationships are particularly important in the the resource estimate is based
mineralisation reporting of Exploration Results. were vertical and approximately
widths and perpendicular to the thickness
intercept of the sub horizontal mineralisation.
lengths * If the geometry of the mineralisation with respect to
the drill hole angle is known, its nature should be
reported.
* 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 -- Refer to the ASX announcement
* Appropriate maps and sections (with scales) and which this table accompanies.
tabulations of intercepts should be included for any
significant discovery being reported 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 practicable, representative reporting
of both low and high grades and/or widths should be
practiced to avoid misleading reporting of
Exploration Results.
Other -- Metallurgical testwork
substantive * Other exploration data, if meaningful and material, is ongoing. Information on
exploration should be reported including (but not limited to): processing has been reported
data geological observations; geophysical survey results; in ASX announcement: 29 July
geochemical survey results; bulk samples - size and 2019 "Tiris Uranium Definitive
method of treatment; metallurgical test results; bulk Feasibility Study Completed".
density, groundwater, geotechnical and rock -- ASX Release 23(rd) June
characteristics; potential deleterious or 2022 confirms average 550%
contaminating substances. upgrading of uranium with
simple screening in test-work.
Further -- In the Oued El Foule and
work * The nature and scale of planned further work (eg Oued El Foule Sud tenements
tests for lateral extensions or depth extensions or drilling is planned to test
large-scale step-out drilling). smaller radiometric anomalies
that have not been drilled,
and several larger anomalies
* Diagrams clearly highlighting the areas of possible that have only been assessed
extensions, including the main geological by wide-spaced drill lines
interpretations and future drilling areas, provided that show promising results.
this information is not commercially sensitive.
=============== =============================================================== ========================================================
Section 3. Estimation and Reporting of Mineral Resources -
PART 1
Note this Section 3 has been prepared by H&S Consultants and
relates to the Hippolyte North, Hippolyte South, Lazare North,
Lazare South, and Sadi Resources
Criteria JORC Code explanation Commentary
==================== ======================================================================= =======================
Database integrity Aura's resource
* Measures taken to ensure that data has not been database
corrupted by, for example, transcription or keying was managed by Reflex
errors, between its initial collection and its use Hub
for Mineral Resource estimation purposes. during the programs
prior
to July 2019 and
* Data validation procedures used. managed
by Earth SQL after
that date.
Analyses were
forwarded directly
from the laboratories
to
the database manager
for
incorporation in the
database.
H&SC conducted some
basic
checks for internal
inconsistencies
such as overlapping
intervals,
records beyond end of
hole
depth, unassayed
intervals
and unrealistic drill
hole
data.
==================== ======================================================================= =======================
Site visits The Competent Person
* Comment on any site visits undertaken by the for
Competent Person and the outcome of those visits. the recent Mineral
Resource
Estimate (MRE) has not
* If no site visits have been undertaken indicate why visited
this is the case. the Tiris deposits due
to
time and budget
constraints.
H&SC bases its view of
the
geological setting and
mineralisation
on drill hole data,
discussions
with Aura geologists
and
on information in
technical
reports.
Representatives
of Coffey Mining and
Wardell
Armstrong
International
conducted
site visits in Aril
2012
and May 2016
respectively.
==================== ======================================================================= =======================
Geological The uranium
interpretation * Confidence in (or conversely, the uncertainty of) the mineralisation
geological interpretation of the mineral deposit. generally forms thin
shallow
horizontal tabular
* Nature of the data used and of any assumptions made. bodies
ranging in thickness
from
* The effect, if any, of alternative interpretations on 1 to 12 m hosted in
Mineral Resource estimation. weathered
granite and granitic
sediments.
* The use of geology in guiding and controlling Mineral Differentiation of the
Resource estimation. weathered
granite from granitic
sediments
* The factors affecting continuity both of grade and is unreliable from AC
geology. sample
returns. A purely
geological
model of the Tiris
deposits
has not been produced.
H&SC created a surface
representing
the base of the
estimates
in order to limit the
extrapolation
of grades into volumes
that
had no data. This is
important
at Tiris as there is a
general
decrease in uranium
grades
with depth. This
surface
nominally represents
the
top of the
less-weathered
granite, where AC
drilling
could penetrate no
further.
The base surface was
produced
using the locations of
the
end of the deepest
assay
from each drill hole.
Where
drill holes were very
close,
within around 15 m,
the shallower
point was generally
removed.
Areas of obvious
outcrop
were excised from the
MRE
assuming a dip of 45
degrees
between weathered
granite/granitic
sediments and the
less-weathered
granite.
The vast majority of
the
recent drill collar
locations
were surveyed using a
Differential
Global Positioning
System
(DGPS). H&SC used the
locations
of all drill hole
collars
that had been located
with
the DGPS to create a
wireframe
representing the
topographic
surface. The
elevations of
all drill holes that
had
been located using a
handheld
GPS were then derived
from
this topographic
surface.
At the time that the
estimates
were completed, no
topographic
survey data were
available.
The proportion of each
block
between the
topographic and
base surfaces, as well
as
the proportion of
outcrop,
were assigned to the
block
model and used to
weight
the reported
estimates.
The interpretation of
the
mineralisation as flat
lying
tabular bodies is
undisputed.
The lateral extents of
the
mineralisation are
poorly
defined and additional
drilling
around the edges of
the deposits
may indicate that
mineralisation
is more limited than
currently
interpreted.
The extent of
outcrop/subcrop
and its relationship
to free-digging
mineralisation is
somewhat
uncertain but a
conservative
approach has been
taken to
minimise this risk.
Alternative
interpretations
of the geology are
unlikely
to significantly
impact estimated
resources.
The continuity of both
grade
and geology are
affected
by the extent of
weathering
of the granitic host.
The
continuity does not
appear
to be affected by
faulting.
==================== ======================================================================= =======================
Dimensions The Mineral Resources
* The extent and variability of the Mineral Resource reported
expressed as length (along strike or otherwise), plan here occur in five
width, and depth below surface to the upper and lower separate
limits of the Mineral Resource. areas (Hippolyte
North, Hippolyte
South, Lazare North,
Lazare
South and Sadi) within
a
rectangle around 32 km
north-south
and 42 km east-west.
All
mineralisation forms
flat
lying tabular bodies
ranging
in thickness from 1 to
12
m.
The Mineral Resources
at
Hippolyte North at a
cut-off
of 100 ppm U3O8 occur
in
an area 6 km east-west
and
5.5 km north-south.
This
region is comprised of
several
separate areas that
range
in plan dimensions
from 500
m to 1.1 km wide and
500
m to 2.2 km long. The
upper
limit of the
mineralisation
occurs at surface and
the
reported resources
reach
a maximum depth of 11
m below
surface.
The Mineral Resources
at
Hippolyte South at a
cut-off
of 100 ppm U3O8 occur
in
an area 5.6 km
east-west
and 5.4 km
north-south. This
region is comprised of
three
isolated areas each
with
a north-south length
of around
1.3 km and an
east-west length
that ranges 400 m to
1.1
km. The upper limit of
the
mineralisation occurs
at
surface and the
reported
resources reach a
maximum
depth of six metres
below
surface.
The Mineral Resources
at
Lazare North at a
cut-off
of 100 ppm U3O8 occur
in
an area 4.5 km
east-west
and 2.4 km
north-south. This
region is comprised of
three
isolated areas. The
smallest
of these areas has an
east-west
length of 900 m and a
north-south
length of 550 m. The
largest
area has an east-west
length
of 2.2 km m and a
north-south
length of 1.8 km. The
upper
limit of the
mineralisation
occurs at surface and
the
reported resources
reach
a maximum depth of 12
m below
surface.
The Mineral Resources
at
Lazare South at a
cut-off
of 100 ppm U3O8 occur
in
an irregular shape
with an
east-west length of
5.5 km
and a north-south
length
of 2.7 km. The largest
area
has an east-west
length of
2.2 km m and a
north-south
length of 1.8 km. The
upper
limit of the
mineralisation
occurs at surface and
the
reported resources
reach
a maximum depth of 10
m below
surface.
The Mineral Resources
at
Sadi at a cut-off of
100
ppm U3O8 occur in an
irregular
NNW trending area with
an
east-west length of 5
km
and a north-south
length
of 9 km. The upper
limit
of the mineralisation
occurs
at surface and the
reported
resources reach a
maximum
depth of 14 m below
surface.
==================== ======================================================================= =======================
Estimation and New estimates were
modelling * The nature and appropriateness of the estimation generated
techniques technique(s) applied and key assumptions, including for Hippolyte North -
treatment of extreme grade values, domaining, Zone
interpolation parameters, maximum distance of 3, Lazare South and
extrapolation from data points. Sadi
deposits. Existing
estimates
* The availability of check estimates, previous for the remainder of
estimates and/or mine production records and whether Hippolyte
the Mineral Resource estimate takes appropriate North, Hippolyte South
account of such data. and
Lazare North were
updated
* The assumptions made regarding recovery of using recent outcrop
by-products. mapping
to excise areas that
may
* Estimation of deleterious elements or other non-grade not be amenable to
variables of economic significance (e.g. sulphur for free digging.
acid mine drainage characterisation). The uranium
concentrations
were estimated by
* In the case of block model interpolation, the block recoverable
size in relation to the average sample spacing and Multiple Indicator
the search employed. Kriging
(MIK) using the GS3
geostatistical
* Any assumptions behind modelling of selective mining software. The uranium
units. grades
at the Tiris deposits
exhibit
* Any assumptions about correlation between variables. a positively skewed
distribution
and therefore show
* Description of how the geological interpretation was reasonable
used to control the resource estimates. sensitivity to a small
number
of high grades. MIK is
* Discussion of basis for using or not using grade considered
cutting or capping. an appropriate
estimation
method for the uranium
* The process of validation, the checking process used, grade
the comparison of model data to drill hole data, and distribution at the
use of reconciliation data if available. Tiris
deposits because it
specifically
accounts for the
changing
spatial continuity at
different
grades through a set
of indicators
variograms at a range
of
grade thresholds. It
also
reduces the need to
use the
practice of top
cutting.
All drill hole
intervals
were composited to 0.5
m
for estimation.
No top-cuts were
applied
but the average of the
mean
and median grades was
applied
to the top indicator
class
to address any
potential
extreme values.
The five deposits were
subdivided
into a number of
Subzones
for estimation, with
conditional
statistics generated
for
each of the Subzones.
All
class grades used for
estimation
of the mineralised
domains
were derived from the
class
mean grades, except
the top
indicator class.
Only U(3) O(8) was
estimated.
No assumptions were
made
regarding the
correlation
of uranium with any
other
variable. No
deleterious
elements or other
non-grade
variables of economic
significance
were estimated.
The base surface
created
to represent the top
of the
less-weathered granite
was
used to limit the
extrapolation
of grades into volumes
that
had no data.
The proportion of
outcrop
was estimated for each
block
based on digitising
provided
by Aura and used to
deplete
the MRE on the
assumption
that this material
cannot
be dug freely.
No assumptions were
made
regarding the recovery
of
by-products. Uranium
was
assumed to be the only
element
present in
economically
significant
concentrations,
although
vanadium is known to
occur
with the uranium in
the main
ore mineral carnotite
and
could potentially be
recovered.
The Recoverable MIK
technique
employed by H&SC in
this
case requires a set of
14
variogram models, one
for
each of the fourteen
grade
bins used. A set of
variogram
models were created
for Subzones
of the Hippolyte
North, Lazare
South and Sadi
deposits.
These variogram models
were
applied to Subzones
that
did not have
sufficient data
to generate reliable
models.
Most deposits have
areas
that have been drilled
on
50x50 m or 70x70 m
grids
whereas the Hippolyte
South
areas have only been
drilled
on a 100x100 m grid.
Separate
block models were
created
for Hippolyte North,
Lazar
North, Lazar South,
Hippolyte
South and Sadi
deposits.
Nominal downhole
sampling
interval is 0.5 m.
Drill
hole grade data were
composited
to 0.5 m intervals.
The block
dimensions were 50 x
50 m
in plan view and 1 m
vertically.
The plan dimensions
were
chosen as it is the
nominal
drill hole spacing
(preferable
for MIK estimation).
The
vertical dimension was
chosen
to reflect the
anisotropy
of the mineralisation
and
the downhole data
spacing.
The minimum selective
mining
unit size is assumed
to be
10x10x0.5 m.
A three-pass search
strategy
was used to estimate
the
U3O8 grades at each of
the
deposits. Each pass
required
a minimum number of
samples
with data from a
minimum
number of octants of
the
search ellipse to be
populated.
Discretisation was set
to
5x5x2 points in X, Y
and
Z respectively. The
search
criteria are shown
below.
The last short axis of
the
search ellipse is
vertical.
1. 80x80x2.0m search,
16-48
samples, minimum 4
octants
2. 160x160x2.0m
search, 16-48
samples, minimum 4
octants
3. 240x240x3.0m
search, 8-48
samples, minimum 2
octants
The maximum distance
of extrapolation
of the reported
estimates
from drill hole data
points
is limited to around
220
m.
The Hippolyte North
and Lazar
North deposits were
estimated
by Mr. Mapeto of
Coffey Mining
in 2011. Lazar South
was
estimated by Mr.
Mapeto in
2012. H&SC has access
to
these block models and
considers
that the current
Mineral
Resource Estimate
takes appropriate
account of these
models.
Significant additional
drilling
has occurred since
these
estimates were
produced so
the volume and
confidence
category have
increased.
Reasonably large
differences
exist between the
current
and previous estimates
due
to differences in
estimation
methodologies.
No check estimates
were produced.
No mining has occurred
on
the Tiris deposits so
mine
production data were
unavailable
for comparison.
The final H&SC block
model
was reviewed visually
by
H&SCa, and it was
concluded
that the block model
reasonably
represents the grades
observed
in the drill holes.
H&SC
also validated the
block
model statistically
using
histograms, boxplots,
scatter
plots and summary
statistics.
==================== ======================================================================= =======================
Moisture Tonnages are estimated
* Whether the tonnages are estimated on a dry basis or on
with natural moisture, and the method of a dry weight basis.
determination of the moisture content. The moisture
constant was not
determined.
==================== ======================================================================= =======================
Cut-off parameters A cut-off of 100 ppm
* The basis of the adopted cut-off grade(s) or quality U3O8
parameters applied. cut off is used to
report
the resources as it is
assumed
that ore can be
economically
mined at this grade in
an
open pit scenario.
This cut-off
is considered to be
relatively
low compared to
operating
uranium mines, but
metallurgical
test work indicates
that
a significant upgrade
in
uranium and decrease
in sulphates
can be achieved by a
simple
screening process.
==================== ======================================================================= =======================
Mining factors or All of the resources
assumptions * Assumptions made regarding possible mining methods, reported
minimum mining dimensions and internal (or, if here have been
applicable, external) mining dilution. It may not estimated
always be possible to make assumptions regarding on the assumption that
mining methods and parameters when estimating Mineral the
Resources. Where no assumptions have been made, this deposits will be mined
should be reported. by
open-pit.
Recoverable MIK allows
for
block support
correction
to account for the
change
from sample size
support
to the size of a
mining block.
This process requires
an
assumed grade control
drill
spacing and the
assumed size
of the Selective
Mining Unit
(SMU). The variance
adjustment
factors were estimated
from
the U3O8 metal
variogram
models assuming a
minimum
SMU of 10x10x0.5
metres (east,
north, vertical) with
high
quality grade control
sampling
on a 10x10x0.5 metre
pattern
(east, north,
vertical).
The application of the
variance
adjustments to the
resource
estimates is expected
to
provide estimates of
recoverable
resources without the
need
to apply additional
mining
dilution or mining
recovery
factors. Internal
dilution,
that is, within the
SMU unit
is accounted for. If a
larger
SMU size or a broader
grade
control drill pattern
is
implemented the
selectivity
assumed in the
reported resources
may not be realised.
==================== ======================================================================= =======================
Metallurgical The metallurgical test
factors or * The basis for assumptions or predictions regarding work
assumptions metallurgical amenability. It may not always be information supplied
possible to make assumptions regarding metallurgical to H&SC
treatment processes and parameters when reporting indicates that the
Mineral Resources. Where no assumptions have been Tiris
made, this should be reported. deposits are amenable
to
a process of crushing,
screening
and an alkaline
carbonate
leach in order to
recover
uranium. Bench scale
test
work indicates that a
significant
upgrade in uranium and
decrease
in sulphate
concentrations
can be achieved
through screening.
No penalty elements
identified
in work so far.
No other assumptions
have
been made.
==================== ======================================================================= =======================
Environmental Aura has informed H&SC
factors or * Assumptions made regarding possible waste and process that
assumptions residue disposal options. It is always necessary as an Environmental and
part of the process of determining reasonable Social
prospects for eventual economic extraction to Impact Assessment has
consider the potential environmental impacts of the been
mining and processing operation. While at this stage completed which
the determination of potential environmental impacts, concluded
particularly for a greenfields project, may not there are no known
always be well advanced, the status of early issues
consideration of these potential environmental arising from native
impacts should be reported. Where these aspects have title,
not been considered this should be reported with an historical sites,
explanation of the environmental assumptions made. environmental
or third-party matters
which
are likely to
materially
affect exploitation.
H&SC
therefore assume that
there
are no known unusual
aspects
of the Tiris deposits
that
may lead to adverse
environmental
impacts beyond what is
expected
from a mining
operation.
Waste rock and process
residue
is expected to be
disposed
of in the areas
surrounding
the deposits and
processing
facility in a
responsible
manner and in
accordance
with all mining lease
conditions.
==================== ======================================================================= =======================
Bulk density Dry bulk density of
* Whether assumed or determined. If assumed, the basis diamond
for the assumptions. If determined, the method used, drill core was
whether wet or dry, the frequency of the measurements, measured at
the nature, size and representativeness of the the ALS facility in
samples. Nouakchott
using an immersion
method
(Archimedes principle)
on
selected PQ diamond
drill
core intervals ranging
in
size from 10 to 30 cm.
Competent
pieces of drill core
were
selected on a nominal
interval
of 50 cm. The samples
chosen
are believed to be
representative
of the surrounding
rock type.
All density samples
are wrapped
in cling film to avoid
water
absorption. A total of
412
density measurements
have
been taken from drill
core
at the Tiris deposits
with
values ranging from
1.50
to 2.66 t/m3 and
averaging
2.13 t/m3.
Measured density
values show
that there is a
reasonable
correlation between
density
and the depth of the
sample.
A regression was used
to
assign densities to
each
block in the block
model
based on the depth
below
surface.
==================== ======================================================================= =======================
Classification The classification is
* The basis for the classification of the Mineral based
Resources into varying confidence categories. on the search pass
used to
estimate the block.
* Whether appropriate account has been taken of all In some cases, the
relevant factors (i.e., relative confidence in blocks
tonnage/grade estimations, confidence in continuity at surface were
of geology and metal values, quality, quantity and populated
distribution of the data). in a later search pass
than
blocks immediately
* Whether the result appropriately reflects the below,
Competent Person's view of the deposit. as these blocks did
not meet
the minimum search
criteria
due to the fact that
there
are no samples above
the
topography. In order
to alleviate
this, the minimum
search
pass from a column of
blocks
was propagated
upwards.
Pass one nominally
equates
to Measured Resources,
pass
two translates to
Indicated
Resources and Pass
three
equates to Inferred
Resources.
This scheme is
considered
by H&SC to take
appropriate
account of all
relevant factors,
including the relative
confidence
in tonnage and grade
estimates,
confidence in the
continuity
of geology and metal
values,
and the quality,
quantity
and distribution of
the data.
The classification
appropriately
reflects the Competent
Person's
view of the deposit.
==================== ======================================================================= =======================
Audits or reviews This Mineral Resource
* The results of any audits or reviews of Mineral estimate
Resource estimates. has been reviewed by
Aura
personnel. The
estimation
procedure has also
been internally
reviewed by H&SC. No
material
issues were identified
as
a result of these
reviews.
No independent
external audits
have been completed on
the
Mineral Resource
estimates.
==================== ======================================================================= =======================
Discussion of The relative accuracy
relative accuracy/ * Where appropriate a statement of the relative and
confidence accuracy and confidence level in the Mineral Resource confidence level in
estimate using an approach or procedure deemed the Mineral
appropriate by the Competent Person. For example, the Resource estimates are
application of statistical or geostatistical considered
procedures to quantify the relative accuracy of the to be in line with the
resource within stated confidence limits, or, if such generally
an approach is not deemed appropriate, a qualitative accepted accuracy and
discussion of the factors that could affect the confidence
relative accuracy and confidence of the estimate. of the nominated JORC
Mineral
Resource categories.
* The statement should specify whether it relates to This
global or local estimates, and, if local, state the has been determined on
relevant tonnages, which should be relevant to a
technical and economic evaluation. Documentation qualitative, rather
should include assumptions made and the procedures than
used. quantitative, basis,
and
is based on the
* These statements of relative accuracy and confidence estimator's
of the estimate should be compared with production experience with a
data, where available. number
of deposits at NPM and
similar
deposits elsewhere.
The main
factors that affect
the relative
accuracy and
confidence of
the estimate are the
drill
hole spacing and the
style
of mineralisation.
The estimates are
local,
in the sense that they
are
localised to model
blocks
of a size considered
appropriate
for local grade
estimation.
The tonnages relevant
to
technical and economic
analysis
are those classified
as Measured
and Indicated Mineral
Resources.
This deposit remains
unmined
so there are no
production
records for
comparison.
==================== ======================================================================= =======================
Section 3. Estimation and Reporting of Mineral Resources -
PART 2
Note: This Section 3 has been prepared by Oliver Mapeto and
relates to the Hippolyte zones C, E, F, G (Marie, Hippolyte
West), Ferkik East & Ferkik West Resources
Criteria Explanation Deposit Specific Information
================ ================================================================ ==================================
Database Aura's database was managed
integrity * Measures taken to ensure that data has not been by the independent organisation
corrupted by, for example, transcription or keying Reflex Hub, based in Perth.
errors, between its initial collection and its use The consultant conducted
for Mineral Resource estimation purposes. data validation checks including
comparing assay certificates
to database records and
* Data validation procedures used. a variety of checks for
internal inconsistencies
such as overlapping intervals,
records beyond end of hole
depth, unassayed intervals,
and unrealistic drill hole
data. Additional checks
included collar details
checks. Unrealistic RL on
historical data based on
new survey data were adjusted
using nearest neighbour.
================ ================================================================ ==================================
Site visits Site visit to the project
* Comment on any site visits undertaken by the area was conducted by the
Competent Person and the outcome of those visits. Consultant in April 2012
(Coffey Mining). No site
visit was conducted during
* If no site visits have been undertaken indicate why the recent 2015 Sadi South
this is the case. extension drilling campaign.
However, based on previous
site visit the consultant
is familiar with geological
setting and mineralisation
style.
================ ================================================================ ==================================
Geological The uranium mineralisation
interpretation * Confidence in (or conversely, the uncertainty of) the generally forms shallow
geological interpretation of the mineral deposit. horizontal tabular bodies
ranging in thickness from
1 to 12m hosted in weathered
* Nature of the data used and of any assumptions made. granite, granitic sediments,
and calcrete. Differentiation
of the weathered granite
* The effect, if any, of alternative interpretations on from granitic sediments
Mineral Resource estimation. is unreliable from AC sample
returns. A purely geological
model of the Tiris deposits
* The use of geology in guiding and controlling Mineral has not been produced.
Resource estimation. The material above the top
of ore is waste largely
made of loose sandy material.
* The factors affecting continuity both of grade and The base of ore defines
geology. the top of consolidated
material, harder going into
unmineralized granite basement.
Ore surfaces representing
the top and base of the
mineralisation using a grade
cut-off of 100 ppm U308
were generated across all
project areas and mineralised
zones. The top and base
of ore surfaces were used
as hard boundaries to control
grade estimation.
A lower cut-off grade of
75 ppm U308 was used to
model the Sadi South. Due
to the nature of the
mineralisation,
the change in lower cut-off
grade had marginal changes
on the mineralised volumes.
The grade varied significantly
within the drill hole
intersections.
At the time that the estimates
were completed, the natural
topographical surface was
not available. The 2012
drill data had no topographic
survey data available. Most
of the 2015 and 2017 drill
collar locations were surveyed
using a Differential Global
Positioning System (DGPS).
The consultant used drill
hole collars that had been
located with the DGPS to
create a wireframe representing
the topographic surface.
The elevations of all drill
holes with no survey were
then interpolated using
the nearest neighbour.
The interpretation of the
mineralisation as flat lying
tabular bodies was defined
with high confidence by
the top and base of ore
surfaces.
In some zones, pods of low-grade
mineralisation occur showing
moderate continuity of both
grade and geology. The
mineralisation
is recent and unaffected
by faulting.
================ ================================================================ ==================================
Dimensions The Mineral Resource as
* The extent and variability of the Mineral Resource reported in the 2011 Resource
expressed as length (along strike or otherwise), plan estimate lie in the following
width, and depth below surface to the upper and lower areas, Sadi South, Sadi
limits of the Mineral Resource. North, Marie, Hippolyte
W, Hippolyte E, Oum Ferkik
West and Oum Ferkik East.
Sadi South resource has
since been updated following
infill and extension drilling
campaign in 2015.
The Mineral Resources estimates
applied a lower a cut-off
grade of 100 ppm U3O8 was
applied across all project's
areas.
Marie occurs in an area
1.2 km east-west and 6 km
north-south. This region
is comprised of six separate
zones that range in plan
dimensions from 200m to
1.2 km wide and 500 m to
1.4km long.
Hippolyte W occurs in an
area 0.8 km east-west and
2.0 km north-south. This
region is comprised of three
separate zones that range
in plan dimensions from
150m to 400m wide and 400
m to 1.0km long
Hippolyte E occurs in an
area 3.0 km east-west and
4.0 km north-south. This
region is comprised of three
separate zones that range
in plan dimensions from
150m to 600m wide and 400
m to 600m long.
Oum Ferkik West occurs as
a single zone with dimensions
of 1.6 km east-west and
2.5 km north-south.
Oum Ferkik East occurs in
an area 2.0 km east-west
and 2.0 km north-south.
This region is comprised
of six separate zones that
range in plan dimensions
from 150m to 400m wide and
400 m to 1.2km long
Mineralisation forms flat
lying tabular bodies ranging
in thickness from 1 to 12m
with some internal waste
patches occurring within
the mineralisation envelope.
In places, there the top
of mineralisation is covered
by sand or waste overburden.
================ ================================================================ ==================================
Estimation The uranium concentrations
and * The nature and appropriateness of the estimation were estimated using the
modelling technique(s) applied and key assumptions, including Ordinary Kriging estimation
techniques treatment of extreme grade values, domaining, method.
interpolation parameters, maximum distance of Sample database has assays
extrapolation from data points. samples at a nominal 1m
sample interval. Some samples
were sampled at 0.5m interval
* The availability of check estimates, previous using overburden-ore contact
estimates and/or mine production records and whether depending on thickness of
the Mineral Resource estimate takes appropriate topsoil (sand).
account of such data. 2m sample composite were
created for grade estimation.
Area specific high-grade
* The assumptions made regarding recovery of assays top cuts were applied
by-products. to minimise grade spearing.
The top-cut values were
chosen by assessing the
* Estimation of deleterious elements or other non-grade high-end distribution of
variables of economic significance (e.g. sulphur for the grade population within
acid mine drainage characterisation). each zone and selecting
the value at which the
distribution
* In the case of block model interpolation, the block became erratic
size in relation to the average sample spacing and Each zone was divided into
the search employed. subzones for grade estimation.
The subzones were based
on defined solid using a
* Any assumptions behind modelling of selective mining 100ppm lower U308 grade
units. cut-off. Each zone was coded
and only samples within
the same matching zone code
* Any assumptions about correlation between variables. were used in estimation.
Additional estimation parameters
were applied as follows:
* Description of how the geological interpretation was A three-pass estimation
used to control the resource estimates. strategy was adopted to
estimate the U(3) O(8) grades.
The estimation search parameters
* Discussion of basis for using or not using grade are shown below for estimation
cutting or capping. run pass 1, 2 and 3. The
short first axis of the
search ellipse is vertical.
* The process of validation, the checking process used, Pass 1. 300x200x6m search,
the comparison of model data to drill hole data, and 8-24 samples
use of reconciliation data if available. Pass 2. 360x250x6m search,
6-24 samples
Pass 3. 600x400x6m search,
4-24 samples
In addition, upper cut-off
grade specific to the ore
zones were applied.
Vanadium is a potential
by-product and vanadium
oxide (V(2) O(5) ) has been
estimated for the mineral
resources using the
stoichiometric
V(2) O(5) /U(3) O(8) ratio
for carnotite group minerals.
These V(2) O(5) values represent
potentially recoverable
vanadium in carnotite and
not total vanadium occurring
in mineralisation, which
is significantly higher
in almost all cases. These
potentially recoverable
V(2) O(5) values are based
on the analysis of a substantial
database of available sample
data and represent average
values that may be conservative.
This procedure relies on
the correlation between
uranium and vanadium in
carnotite group minerals,
which are the only uranium
minerals identified to date
at Tiris.
No deleterious elements
or other non-grade variables
of economic significance
have been identified or
estimated.
Vanadium resource was estimated
using the stoichiometric
V(2) O(5) /U(3) O(8) ratio
for carnotite group minerals
as discussed above
Drill hole drill spacing
is generally regular grid
approximately 100x 200m
over 2.5 x1.4km
Parent block model size
was 50 x 50x 2m
Sub-block size 5 x 5 x 0.5m
The vertical dimension was
chosen to reflect the anisotropy
of the mineralisation and
the downhole data spacing.
A three-pass search strategy
was used to estimate the
U(3) O(8) grades in Sadi
South 2021 Mineral Resource
update. Each pass required
a minimum number of samples
with data from a minimum
number of samples in the
search ellipse to be populated
with discretistion 5x5x2.
The search criteria are
shown below. The short first
axis of the search ellipse
is vertical.
Pass 1. 250x250x12m search,
12-24 samples
Pass 2. 350x350x12m search,
8-24 samples
Pass 3. 500x500x12m search,
6-24 samples
Block model grade estimates
were validated using the
following methods:
Statistical comparison of
block model grades against
drill composite grades by
zone
Visual check of cross sections,
transverse, and long sections
Plan views of grade distribution
Comparison of block model
and drill data grade distribution
using histograms
================ ================================================================ ==================================
Moisture Tonnages are estimated on
* Whether the tonnages are estimated on a dry basis or a dry weight basis. The
with natural moisture, and the method of moisture constant was not
determination of the moisture content. determined.
================ ================================================================ ==================================
Cut-off A cut-off of 100 ppm U(3)
parameters * The basis of the adopted cut-off grade(s) or quality O(8) cut off is used to
parameters applied. report the resources as
it is assumed that ore can
be economically mined at
this grade in an open pit
scenario. This cut-off is
considered to be relatively
low compared to operating
uranium mines, but metallurgical
test work indicates that
a significant upgrade in
uranium and decrease in
sulphates can be achieved
by a simple
Mineralisation occurs as
a Uranium vanadate mineral
and there is potential of
recovery of vanadium as
by product which justifies
a lower U308 grade cut-off
based on information supplied
to the Consultant following
recent leaching test work
on the Tiris Uranium Project
on uranium and Vanadium.
================ ================================================================ ==================================
Mining The resources reported here
factors * Assumptions made regarding possible mining methods, have been estimated on the
or assumptions minimum mining dimensions and internal (or, if assumption that the deposits
applicable, external) mining dilution. It may not will be mined by open pit
always be possible to make assumptions regarding mining method.
mining methods and parameters when estimating Mineral Analysis was done for grade
Resources. Where no assumptions have been made, this continuity and variography.
should be reported. However, in some cases,
no reliable variogram structure
could defined on a zone
by zone basis. The global
variogram was assumed as
this could have been affected
by lack of data due to limited
extend of the individual
mineralised zones.
Parent block model size
was 50 x 50x 2m
Sub-block size 5 x 5 x 0.5m
The selected sub-blocks
were appropriate for minimum
selective mining unit.
================ ================================================================ ==================================
Metallurgical The metallurgical test work
factors * The basis for assumptions or predictions regarding information supplied to
or assumptions metallurgical amenability. It may not always be the consultant is based
possible to make assumptions regarding metallurgical on reports by H&SC which
treatment processes and parameters when reporting indicates that the Tiris
Mineral Resources. Where no assumptions have been deposits are amenable to
made, this should be reported. a process of crushing, screening
and an alkaline carbonate
leach in order to recover
uranium. Bench scale test
work indicates that a significant
upgrade in uranium and decrease
in sulphate concentrations
can be achieved through
screening.
No penalty elements identified
in work done to date.
No other assumptions have
been made.
Metallurgical test work
on Tiris ore has shown that
about 55% to 58% of vanadium
was also extracted during
the alkaline leach. The
V(2) O(5) /U(3) O(8) ratios
for the final leach liquor
are close to the carnotite
V(2) O(5) /U(3) O(8) ratio,
indicating that effectively
only vanadium from carnotite
is being leached under these
conditions. To date, no
vanadium extraction test
work has been carried out
for the recovery of vanadium
from the pregnant leach
solution, so further work
is required to demonstrate
that a marketable vanadium
product can be produced
on a commercial basis.
No further assumptions have
been made.
================ ================================================================ ==================================
Environmental Aura completed an Environmental
factors * Assumptions made regarding possible waste and process and Social Impact Assessment
or assumptions residue disposal options. It is always necessary as which concluded there are
part of the process of determining reasonable no known issues arising
prospects for eventual economic extraction to from native title, historical
consider the potential environmental impacts of the sites, environmental or
mining and processing operation. While at this stage third-party matters which
the determination of potential environmental impacts, are likely to materially
particularly for a greenfields project, may not affect exploitation. The
always be well advanced, the status of early consultant therefore assumes
consideration of these potential environmental that there are no known
impacts should be reported. Where these aspects have unusual aspects of the Tiris
not been considered this should be reported with an Uranium deposits that may
explanation of the environmental assumptions made. lead to adverse environmental
impacts beyond what is expected
from a mining operation.
Waste rock and process residue
is expected to be disposed
of in the areas surrounding
the deposits and processing
facility.
================ ================================================================ ==================================
Bulk density The Mineral Resource estimates
* Whether assumed or determined. If assumed, the basis for Marie, Hippolyte W,
for the assumptions. If determined, the method used, Oum Ferkik West and Oum
whether wet or dry, the frequency of the measurements, Ferkik East used an average
the nature, size, and representativeness of the density of 2.0/g/cc dry
samples. bulk density based on test
done by Aura Energy. This
was considered realistic
for material and ore similar
ore deposits.
In the August 2021 Sadi
South resource update, an
average density value of
2.1g/cc dry bulk density
was applied based on previous
work as reported by H &
S Consultants
================ ================================================================ ==================================
Classification The Mineral Resource estimates
* The basis for the classification of the Mineral for Marie, Hippolyte W,
Resources into varying confidence categories. Oum Ferkik West and Oum
Ferkik East were based on:
Drill hole drill grid spacing
* Whether appropriate account has been taken of all Mineralisation and grade
relevant factors (i.e., relative confidence in continuity
tonnage/grade estimations, confidence in continuity The grade estimation search
of geology and metal values, quality, quantity, and pass used to estimate the
distribution of the data). block.
All mineral Resource estimates
estimated in 2011 were classified
* Whether the result appropriately reflects the as Inferred.
Competent Person's view of the deposit. Regions where grade was
assigned an average grade
due to insufficient drill
data or isolated drill holes
were not classified.
================ ================================================================ ==================================
Audits This Mineral Resource estimates
or reviews * The results of any audits or reviews of Mineral for Marie, Hippolyte W,
Resource estimates. Oum Ferkik West and Oum
Ferkik east are based on
2011 models and these were
reviewed internally by Coffey
Mining Consultants. No material
issues were identified as
a result of these reviews.
================ ================================================================ ==================================
Discussion The relative accuracy and
of relative * Where appropriate a statement of the relative confidence level in the
accuracy/ accuracy and confidence level in the Mineral Resource Mineral Resource estimates
confidence estimate using an approach or procedure deemed are in line with the generally
appropriate by the Competent Person. For example, the accepted accuracy and confidence
application of statistical or geostatistical of the nominated JORC CODE
procedures to quantify the relative accuracy of the (2012) Mineral Resource
resource within stated confidence limits, or, if such categories. This has been
an approach is not deemed appropriate, a qualitative determined on both qualitative
discussion of the factors that could affect the and quantitative basis.
relative accuracy and confidence of the estimate. The main factor that affects
the relative accuracy and
confidence of the Mineral
* The statement should specify whether it relates to Resource estimate is sample
global or local estimates, and, if local, state the data density and high variability
relevant tonnages, which should be relevant to in uranium grades. Confidence
technical and economic evaluation. Documentation in mineralisation continuity
should include assumptions made and the procedures is moderate. Most blocks
used. were estimated in estimation
run pass 1 and 2.
In regions where the geology
* These statements of relative accuracy and confidence and mineralisation are continuous
of the estimate should be compared with production and grade was estimated
data, where available. in estimation run pass 1,
the confidence in the grade
estimates is high and the
resource was classified
as indicated. The rest of
the resource estimated was
classified as inferred.
Some blocks were not estimated
due to insufficient drill
data particularly at the
margins of the mineralised
pods. Block not estimated
in were assigned an average
grade and these blocks were
not classified.
Closer spaced drilling is
necessary prior to detailed
mine planning studies to
increase confidence in the
mineralisation variability.
There is no record available
of historical production
data.
================ ================================================================ ==================================
[1] ASX & AIM Release: Tiris Uranium Definitive Feasibility
Study completed, 29 July 2019
[2] ASX & AIM Release 16 February 2022 "Aura Defines
Vanadium JORC Resource at Tiris Uranium Project
(3) Totals may vary due to rounded figures.
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