Anglesey Mining PLC Parys Mountain Resource Update

 
TIDMAYM 
 
3rd April 2023 
 
                              Anglesey Mining plc 
 
                         ("Anglesey" or "the Company") 
 
                        Parys Mountain Resource Update 
 
Anglesey Mining plc (AIM:AYM), the UK minerals development company, is pleased 
to announce an updated Mineral Resource Estimate ("MRE") for its 100% owned 
Parys Mountain Cu-Zn-Pb-Ag-Au project located on the isle of Anglesey. The 
resource estimates for the White Rock and Engine Zones have been updated on the 
basis of 10 additional drill holes completed in 2022 and a detailed review of 
the previous geological interpretations. 
 
  * Measured resources are now reported at Parys Mountain for the first time in 
    the project's history. The inclusion of 1.3Mt in the highest confidence 
    category of resource provides a very strong base for the next round of mine 
    optimisation work 
  * The combined MRE for the White Rock and Engine Zones, now referred to as 
    Morfa Du, have been reported at 5.72Mt at 0.4% Cu, 2.30% Zn, 1.24% Pb, 28/t 
    Ag and 0.3g/t Au, or 2.0% Copper Equivalent ("CuEq") / 5.6% Zinc Equivalent 
    ("ZnEq") - reported above a cut-off based on a Net Smelter Revenue ("NSR") 
    of US$45.15/t, including 1.6Mt at 2.5% CuEq in the Engine Zone 
  * The Morfa Du Zone has 5.3Mt (93%) of the resource now reporting to the 
    Measured and Indicated ("M&I") categories (23% Measured and 70% Indicated) 
    and contains 213,000t of combined Zn/Pb/Cu, 4.8Moz silver and 48koz gold 
  * The overall MRE for Parys Mountain, including the Northern Copper Zone 
    which has not yet been updated, is reported at 16.1Mt at 1.0% Cu, 1.3% Zn, 
    0.7% Pb, 15g/t Ag and 0.2g/t Au (1.9% CuEq or 5.3% ZnEq) containing 
    486,000t of combined Zn/Pb/Cu, 7.9Moz silver and 86koz gold 
  * The Company will undertake a similar resource update process for the large 
    Northern Copper Zone including additional drilling, which will be the first 
    into this zone since 2008. As detailed in the RNS dated 28 November 2022, 
    the company believes there is substantial upside to the existing resource 
    base of 9.4Mt, relative to the 1969 internal resource of 32.7Mt (which 
    should not be considered compliant with any modern JORC or NI43-101 
    methodologies) 
  * The updated MRE will provide the foundation for the Pre-Feasibility Study, 
    which will incorporate an optimised mine design layout and results from 
    recently commenced metallurgical testwork 
 
Jo Battershill, Chief Executive of Anglesey Mining, commented: "It is very 
pleasing to have finalised the updated Mineral Resource Estimate for Parys 
Mountain, which for the first time includes significant tonnes in the Measured 
category. This update was completed to provide the most robust resource 
estimate going into the next steps of the project's evaluation. The geology and 
resources form the basis for every other subsequent aspect in the evaluation 
phase, from the mine design through to metallurgy and management of tailings. 
The first inclusion of tonnes in the Measured category demonstrates the 
increased level of confidence the team has in the Parys Mountain project." 
 
"The grade-tonnage curve gives us a high-level of confidence that a robust 
economic development is achievable at Parys Mountain, especially given 
metallurgical testwork has demonstrated the ore could be successfully up-graded 
through pre-concentration methods that reject up to 40% of the mined volumes." 
 
"One other benefit of this exercise has been to highlight the outstanding 
exploration potential of the project. Numerous zones have been identified where 
mineralisation could potentially extend beyond the resource boundary. Many 
drillholes contain 'ore-grade' hits that have not been included in the 
estimate. One of these is the shaft pilot hole with intersections including 
5.8m at 2.6% Cu and 3.0m at 3.0% Cu commencing around 20m below the current 
base of the Morris Shaft. We believe that once mining commences at Parys 
Mountain the probability of finding more ore zones is very high, as with all 
Volcanogenic Massive Sulphide deposits." 
 
Parys Mountain Mineral Resource Estimate 
 
The updated JORC compliant Mineral Resource Estimate (MRE) was prepared by 
Micon International and stands at 16.08Mt at 0.98% Cu, 1.32% Zn, 0.71% Pb, 15g/ 
t Ag and 0.17g/t Au (1.9% CuEq or 5.3% ZnEq), as set out in the table below. 
 
Parys Mountain Resources, Combined March 2023 and January 2021 
 
                                     Grades                         Contained Metal 
Classification Tonnes 
                (Mt)    Cu     Zn     Pb     Ag      Au      Cu     Zn     Pb     Ag     Au 
 
                       (%)    (%)    (%)    (g/t)   (g/t)   (kt)   (kt)   (kt)  (Moz)  (koz) 
 
  Measured      1.30   0.33   2.32   1.28    33     0.43    4.3    30.1   16.6   1.36   18.0 
 
  Indicated     3.98   0.37   2.39   1.29    27     0.23    14.7   95.3   51.5   3.47   29.7 
 
  Inferred     10.79   1.29   0.81   0.43     9     0.11   139.4   87.7   46.6   3.05   38.9 
 
Total          16.06   0.98   1.33   0.71    15     0.17    158    213    115    7.9     86 
 
The previous global resource estimate for Parys Mountain (reported in January 
2021) was 16.9Mt at 1.0% Cu, 1.5% Zn, 0.8% Pb, 17g/t Ag and 0.2g/t Au (2.0% 
CuEq or 5.6% ZnEq). 
 
Morfa Du Mineral Resource Estimate 
 
The updated MRE for the Morfa Du Zone, which contains the White Rock and Engine 
Zone ore shoots, comprises 5.72Mt at 0.36% Cu, 2.30% Zn, 1.24% Pb, 28/t Ag and 
0.28g/t Au (2.0% CuEq or 5.6% ZnEq), as set out in the table below. 
 
Morfa Du Zone Resources, March 2023 
 
                                     Grades                         Contained Metal 
Classification Tonnes 
                (Mt)    Cu     Zn     Pb     Ag      Au      Cu     Zn     Pb     Ag     Au 
 
                       (%)    (%)    (%)    (g/t)   (g/t)   (kt)   (kt)   (kt)  (Moz)  (koz) 
 
  Measured      1.30   0.33   2.32   1.28    33     0.43    4.3    30.4   16.7   1.38   18.3 
 
  Indicated     3.98   0.37   2.39   1.29    27     0.23    14.7   95.3   51.4   3.44   29.7 
 
  Inferred      0.45   0.40   1.41   0.65    25     0.25    1.8    6.4    2.9    0.36   3.6 
 
Total           5.72   0.36   2.30   1.24    28     0.28    20.4  131.7   70.9   5.17   51.3 
 
Notes to table: 
 
  * Mineral Resources are based on JORC Code definitions 
  * Operating costs for mining, processing and G&A were modelled at US$45.15/t 
    of mill feed 
  * An Average Value operating cut-off of US$45.15/t has been applied 
  * Payability varies depending on metal (from 70% up to 97.5%) 
  * Metal prices used in the NSR and CuEq calculations were based on US$3,350/t 
    for Zn, US$2,292/t for Pb, US$9,523/t for Cu, US$25.50oz for Ag and US$1850 
    /oz for Au 
  * Recoveries used in the NSR were based on historical metallurgical testwork 
    and the 2,000t bulk sample processed in 1991 (80% to 82% for Zn, 48% to 80% 
    for Cu, 68% to 78% for Pb, 72% for Ag and 25% for Au to concentrate and 40% 
    for Au to gravity) 
  * Dilution allowance of 5% included 
  * CuEq - Copper equivalent was calculated using the formula set out below: 
      + CuEq = (Cu grade % x Cu Recovery) + (Zn grade % x Zn recovery % x (Zn 
        price / Cu price)) + (Pb grade % x Pb recovery % x (Pb price / Cu 
        price)) + (Ag grade g/t / 31.103 x Ag recovery % x (Ag price / Cu 
        price)) + (Au grade g/t / 31.103 x Au recovery % x (Au price / Cu 
        price)) 
  * It is the opinion of Anglesey Mining and the Competent Persons that all 
    elements and products included in the metal equivalent formula have a 
    reasonable potential to be recovered and sold 
  * Density values were calculated using a linear regression of density versus 
    the combined Cu, Pb, and Zn grade 
  * Rows and columns may not add up exactly due to rounding 
 
On a like-for-like basis, the previous resource estimate of the Morfa Du Zone 
was 6.9Mt at 0.44% Cu, 2.70% Zn, 1.40% Pb, 30g/t Ag and 0.24g/t Au (2.2% CuEq 
or 6.2% ZnEq). The updated resource included a robust review of the geology 
resulting in tighter geological constraints being applied, which resulted in 
previous zones of inferred material being removed. However, it is important to 
note that these areas still represent key target zones for future drilling. 
 
The estimation included the application of higher commodity prices than those 
used in the 2021 MRE, which resulted in the incorporation of lower grade 
material within the interpreted mineralised zone. The test for Reasonable 
Prospect of Eventual Economic Extraction (RPEEE) used higher operating cost 
estimates than the 2021 MRE incorporating recent inflationary factors. Details 
of these changes are provided in the notes to the tables. 
 
The following tables show the updated (2023) and previous (2021) mineral 
resource estimates for White Rock. 
 
White Rock Resources, March 2023 
 
                                     Grades                          Contained Metal 
Classification Tonnes 
                (Mt)    Cu     Zn     Pb     Ag      Au      Cu     Zn     Pb     Ag      Au 
 
                       (%)    (%)    (%)    (g/t)   (g/t)   (kt)   (kt)   (kt)   (Moz)   (koz) 
 
  Measured      0.86   0.23   2.29   1.28    22     0.41    2.0    19.7   11.0   0.60    11.2 
 
  Indicated     2.83   0.23   2.18   1.20    22     0.29    6.5    61.7   34.0   2.02    26.4 
 
  Inferred      0.35   0.31   1.61   0.73    29     0.31    0.7    5.6    2.5    0.32     3.4 
 
Total           4.04   0.28   2.30   1.24    28     0.28    9.3    87.1   47.6   2.95    41.1 
 
 
 
White Rock Resources, January 2021 
 
                                     Grades                         Contained Metal 
Classification Tonnes 
                (Mt)    Cu     Zn     Pb     Ag      Au      Cu     Zn     Pb     Ag     Au 
 
                       (%)    (%)    (%)    (g/t)   (g/t)   (kt)   (kt)   (kt)  (Moz)  (koz) 
 
  Measured 
 
  Indicated     4.71   0.25   2.30   1.23    23     0.30    11.8  108.3   57.9   3.48   45.4 
 

  Inferred      1.26   0.28   2.56   1.26    28     0.30    3.5    32.3   15.9   1.13   12.2 
 
Total           5.97   0.26   2.35   1.24    24     0.30    15.3  140.6   73.8   4.62   57.6 
 
Lower tonnages are due to the tighter geological constraints used in the 
interpretation and the higher costs estimates used in the RPEEE. 
 
The following tables show the updated (2023) and previous (2021) individual 
mineral resource estimates for Engine Zone. 
 
Engine Zone Resources, March 2023 
 
                                     Grades                          Contained Metal 
Classification Tonnes 
                (Mt)    Cu     Zn     Pb     Ag      Au      Cu     Zn     Pb     Ag      Au 
 
                       (%)    (%)    (%)    (g/t)   (g/t)   (kt)   (kt)   (kt)   (Moz)   (koz) 
 
  Measured      0.45   0.52   2.38   1.27    53     0.48    2.3    10.5   5.6    0.76     6.8 
 
  Indicated     1.15   0.71   2.92   1.52    39     0.09    8.1    33.6   17.5   1.45     3.4 
 
  Inferred      0.10   0.72   0.73   0.36     9     0.05    0.7    0.7    0.3    0.03     0.1 
 
Total           1.71   0.66   2.65   1.39    41     0.19    11.2   45.2   23.7   2.25    10.5 
 
 
 
Engine Zone Resources, January 2021 
 
                                     Grades                          Contained Metal 
Classification Tonnes 
                (Mt)    Cu     Zn     Pb     Ag      Au      Cu     Zn     Pb     Ag      Au 
 
                       (%)    (%)    (%)    (g/t)   (g/t)   (kt)   (kt)   (kt)   (Moz)   (koz) 
 
  Measured 
 
  Indicated     0.50   1.36   4.94   2.59    92     0.50    6.8    24.7   12.9   1.48     8.0 
 
  Inferred      0.12   1.73   6.73   3.42    70     0.50    2.1    8.1    4.1    0.27     1.9 
 
Total           0.62   1.43   5.29   2.75    87     0.50    8.9    32.8   14.1   1.75     9.9 
 
The increased tonnages and lower grades for Engine Zone has been driven by the 
combination of extending the areas of modelled mineralisation in the 
interpretation and the incorporation of higher commodity prices. 
 
Northern Copper Zone, Garth Daniel and Deep Engine Zone Mineral Resource 
Estimates 
 
The Northern Copper Zone, Deep Engine Zone and Garth Daniel Zone resource 
estimates were not updated during this process and thereby remain unchanged. 
 
Northern Copper Zone Resources, January 2021 
 
                                     Grades                         Contained Metal 
Classification Tonnes 
                (Mt)    Cu     Zn     Pb     Ag      Au      Cu     Zn     Pb     Ag     Au 
 
                       (%)    (%)    (%)    (g/t)   (g/t)   (kt)   (kt)   (kt)  (Moz)  (koz) 
 
  Measured 
 
  Indicated 
 
  Inferred      9.38   1.27   0.38   0.24     5      0.1   120.1   35.6   22.5   1.5    30.2 
 
Total           9.38   1.27   0.38   0.24     5      0.1   120.1   35.6   22.5   1.5    30.2 
 
Garth Daniel Zone Resources, January 2021 
 
                                     Grades                         Contained Metal 
Classification Tonnes 
                (Mt)    Cu     Zn     Pb     Ag      Au      Cu     Zn     Pb     Ag     Au 
 
                       (%)    (%)    (%)    (g/t)   (g/t)   (kt)   (kt)   (kt)  (Moz)  (koz) 
 
  Measured 
 
  Indicated 
 
  Inferred      0.34   1.89   5.78   2.76    66      0.1    6.4    19.7   9.4    0.7    1.1 
 
Total           0.34   1.89   5.78   2.76    66      0.1    6.4    19.7   9.4    0.7    1.1 
 
Deep Engine Zone Resources, January 2021 
 
                                     Grades                         Contained Metal 
Classification Tonnes 
                (Mt)    Cu     Zn     Pb     Ag      Au      Cu     Zn     Pb     Ag     Au 
 
                       (%)    (%)    (%)    (g/t)   (g/t)   (kt)   (kt)   (kt)  (Moz)  (koz) 
 
  Measured 
 
  Indicated 
 
  Inferred      0.62   1.95   4.21   1.90    23      0.2    12.1   26.1   11.8   0.5    4.0 
 
Total           0.62   1.95   4.21   1.90    23      0.2    12.1   26.1   11.8   0.5    4.0 
 
Notes to table: 
 
  * Mineral Resources are based on JORC Code definitions 
  * Operating costs for mining, processing and G&A were modelled at US$39.08/t 
    of mill feed 
  * An NSR operating cut-off of US$48/t has been applied 
  * Payability of 72% applied 
  * Metal prices used in the NSR and CuEq calculations were based on US$2756/t 
    for Zn, US$2,205/t for Pb, US$5512/t for Cu, US$17.50oz for Ag and US$1275/ 
    oz for Au 
  * Recoveries used in the NSR were based on historical metallurgical testwork 
    and the 2,000t bulk sample processed in 1991 (80% to 82% for Zn, 48% to 80% 
    for Cu, 68% to 78% for Pb, 72% for Ag and 25% for Au to concentrate and 40% 
    for Au to gravity) 
  * No allowance was made for dilution 
  * CuEq - Copper equivalent was calculated using the formula set out below: 
      + CuEq = (Cu grade % x Cu Recovery) + (Zn grade % x Zn recovery % x (Zn 
        price / Cu price)) + (Pb grade % x Pb recovery % x (Pb price / Cu 
        price)) + (Ag grade g/t / 31.103 x Ag recovery % x (Ag price / Cu 
        price)) + (Au grade g/t / 31.103 x Au recovery % x (Au price / Cu 
        price)) 
  * It is the opinion of Anglesey Mining and the Competent Persons that all 
    elements and products included in the metal equivalent formula have a 
    reasonable potential to be recovered and sold 
  * Density values were calculated using a linear regression of density versus 
    the combined Cu, Pb, and Zn grade 
  * Rows and columns may not add up exactly due to rounding 
 
Next Steps 
 
From a mineral resource perspective, the Company will embark on a similar 
remodelling and estimation process for the Northern Copper Zone, Garth Daniel 
Zone and Deep Engine Zone over the course of 2023. 
 
Based on the review of the Northern Copper Zone (released in November 2022), 
management believes there is potential to significantly increase the current 
modelled mineralisation envelope with some additional drilling to confirm some 
of the historical intersections and infill to lift the level of confidence. As 
highlighted in the November update, the current resource estimate of 9.4Mt is 
significantly lower than the internally generated historical resource of 32.7Mt 
from 1970. 
 
Recent work also suggests the potential to extend the high-grade Garth Daniel 
shoot both up and down dip and along strike - perhaps connecting with the 
remaining eastern leg of the Deep Engine Zone. 
 
With the completion of the updated MRE for the White Rock and Engine Zones, now 
referred to as Morfa Du, the Company will now focus on upgrading the 2021 PEA 
to a Pre-Feasibility Study. This process will include the following aspects: 
 
  * Re-optimise the underground development with initial focus on the Morfa Du 
    Zone 
  * Include results of ongoing metallurgical testwork into the preliminary 
    engineering designs, with a particular focus on selecting the preferred 
    pre-concentration method 
  * Preliminary engineering designs for the proposed dry-stack tailings 
    management facility 
  * Preliminary engineering designs for the process plant; and, 
  * Updating the site infrastructure plans including decline portal location, 
    temporary mining waste storage location and supply of utilities 
 
The outputs of a Pre-Feasibility Study would be expected to include selection 
of the final mining and processing methods to take forward into a Feasibility 
Study and declaration of a mining reserve. It would also be expected to 
identify any potential requirements for additional resource, geotechnical and 
metallurgical drilling. 
 
The ongoing Environmental Impact and Social Assessment activities and planning 
consent process will progress concurrently with the PFS. 
 
                       MORFA DU MINERAL RESOURCE UPDATE 
 
                                   APPIX 
 
Parys Mountain Geology and Mineralisation 
 
Lenses of massive Zn-Pb-Cu sulphides at the Parys Mountain deposit in Anglesey, 
in North West Wales, occur at and near the contact between Ordovician shales 
and overlying rhyolites. The rhyolites have been dated as Lower Silurian 
(Parrish 1999) and have a thickness of a few hundred metres. These are 
subsequently overlain by Lower Silurian shales. The rhyolites and shales strike 
north-easterly for 2 km to 3 km and dip to the north. 
 
Minor basalts are present, but there are no intermediate rocks. Cu-bearing 
stockwork veins occur in the upper portion of the Ordovician shales, and 
Cu-bearing mineralisation was mined from the Lower Silurian shales in the 18th 
century. Precambrian basement rocks are present to the south and north of Parys 
Mountain. 
 
A commonly accepted model to explain the field relationships at Parys Mountain 
invokes a large synclinal structure with an east-west axis and a northern limb, 
which is overturned to the south. This limb comprises the Northern shales, the 
Northern rhyolites, and part of the Central shales. The Northern shales contain 
overturned graded sandstone beds. In addition, they contain Ordovician 
acritarchs, which in at least one area become younger to the south. 
 
The property scale synclinal axis is inferred to run for the most part through 
the Central shales, which show common evidence of folding and thrusting on a 
variety of scales. To the west, the Central shales pinch out, such that the 
Northern and Southern rhyolites merge. West of this thick rhyolite sequence, 
the northeast striking Penymynydd fault is present. 
 
The mineralisation of Parys Mountain extends for roughly 3 km, striking NNE to 
SSW in a band 1 km wide. It is associated with an ancient volcanic event (late 
Ordovician circa 480 Ma) involving the extrusion of mostly silica rich 
rhyolites and dacite lavas with ash ejection. 
These deposits grade laterally into the shallow water volcanic sediments which 
include siliceous sinter and cherts and also host intrusive rhyolites and later 
dolerites. This volcanic sequence overlies the Parys shales and is in turn 
overlain by later Silurian shales. These beds appear to have been compressed 
into a steep trough shaped structure striking NE to SW and tilted over to the 

SE. The axis is exposed at the ends of the Great Opencast. The region is also 
traversed by the steep NNW to SSE striking cross faults and to the north there 
are older Precambrian schists of the Mona complex, brought up by the Carmel 
head and Corwas thrust faults. 
 
The primary mineralisation is comprised of pyrite (FeS2) which can be seen in 
the slump structures in the exposures at the centre of the Great Opencast, 
indicating formation on the sea floor. This was followed by a phase dominated 
by chalcopyrite (CuFeS2) and then by one dominated by the intimate mixture of 
sphalerite (ZnS) and galena (PbS) with only minor chalcopyrite. This is known 
locally as "Bluestone". 
 
The mineralisation is believed to have formed from exhalations on the sea floor 
analogous to the black smokers seen in other oceans today. The ore deposit is 
thus thought to be of the "Kuroko" type and as such is unique in Britain. 
 
A secondary phase remobilisation occurred during the later Caledonian 
metamorphism and has been dated to be 360 Ma. 
 
Parys Mountain Modelling and Grade Interpolation 
 
Since the previous resource estimation process in 2021, a further campaign of 
infill drilling has been carried out focusing on the White Rock and Engine 
Zone. This campaign included 10 drillholes being completed between December 
2021 and May 2022. Of the 10 holes completed, 8 showed significant mineralised 
intervals which have added further datapoints for the new Mineral Resource 
model. 
 
Chosen samples from these drillholes were also the subject of specific gravity 
analysis (water immersion method), giving additional density data for the 
mineralised intervals to be utilised in the updated Mineral Resource model. 
 
After updating the Parys Mountain drillhole database to include the 2022 
drillholes, cross sections were generated through the White Rock and Engine 
Zones at 50m spacings utilising the Leapfrog Geo software package. Each assay 
within the drillhole database was assigned a raw-insitu-value, calculated using 
the trailing 3-yr average commodity prices. From this, the company selected a 
cut-off of US$45 to generate the 'mineralised envelope'. The cross sections 
were then used to confirm previous interpretative work or updated based on new 
information. 
 
The sectional interpretations were then geo-referenced into their correct 
position within the Leapfrog model, which allowed for the interpretations to be 
digitised using polylines. These polylines were then used to form a mesh, which 
was used as the extents of the new Mineral Resource model. 
 
Further analysis was also completed on the existing assay database used in the 
previous resource model, which found some inconsistencies with historic 
drilling data. These inconsistencies are detailed here: 
 
  * PM126 had no assay data included in the database, however, assays were 
    available between 99.07 - 102.83m and were subsequently included 
  * PM122 was given an incorrect collar location, dip and azimuth. These were 
    corrected within the database 
  * AMC5 assay data for the interval 278.3 - 285.7m should have read 278.3 - 
    278.9m. This was corrected in the database 
  * A53 assay data for the interval 561.8 - 566.6m was identified as being 
    included as an average across the interval. The database was corrected with 
    the addition of the individual assays for each sample length 
  * CZ13 assay data had been input incorrectly with a transposition error. This 
    was corrected in the database 
  * Elevations of some collars had minor inconsistencies with the LiDAR 
    topography data for the area. All hole coordinates were verified by 
    historic maps, then pinned to the LiDAR data to give their accurate 
    elevation. 
 
Interpretation of the data and previous model has resulted in the Engine Zone 
increasing in size and dip extent. Drilling clearly shows the addition of a new 
western 'limb' within the Engine Zone mineralisation. Re-evaluation of the 
historical project data suggests that drilling included in Deep Engine Zone 
(A51A, PM109), and holes within the same vicinity as Deep Engine Zone (PM108, 
A48, PM113, PM107) are likely to be extensions of the Engine Zone. However, 
additional drilling would be required to confirm and expand the resource at 
depth. 
 
Similarly, White Rock has been extended down-dip to encompass the mineralised 
intervals of A51, A51A and the bottom mineralised interval of PM113, none of 
which had previously been included in any of the previous resource models. 
 
For the Morfa Du Zone resource update, five elements were modelled - Cu, Zn, 
Pb, Ag and Au. The higher-grade populations were separately interpreted and 
wireframed. All the domains were interpreted on a section-by-section basis and 
were used to generate solid '3D' wireframes. The same methodology was applied 
for the individual high-grade populations by commodity. 
 
Within the broader mineralised envelope, wireframes were constructed for the 
Engine Zone and White Rock ore bodies based on assay grades, lithological logs, 
and deposit-scale geological information. High- and low-grade domain wireframes 
were modelled for Ag, Au, Cu, Pb, and Zn within the two separate ore bodies. 
 
Drill hole assay data was composited at 2.0m intervals. Exploratory data 
analysis was performed for each domain to validate geostatistical stationarity, 
identify the nature of the contacts between domains, and to inform outlier 
management. 
 
Normal score variograms were modelled for Ag, Au, Cu, Pb, and Zn in the Engine 
Zone and White Rock ore bodies. Data from high- and low-grade domains were 
combined to ensure sufficient pairs of samples for robust variogram modelling. 
The modelled variograms show similar ranges and principal directions for the 
most strongly correlated elements (Ag, Cu, Pb, and Zn) and are orientated 
parallel to the respective ore body. 
 
A rotated block model dipping 50° to the North was constructed with a parent 
block size of 8.0m (X), 8.0m (Y) and 4.0m (Z) with a sub-block size of 2.0m 
(X), 2.0m (Y) and 2.0m (Z). The Ag, Au, Cu, Pb, and Zn grades for each domain 
were interpolated using ordinary kriging in 3 passes with hard boundaries. The 
orientation and anisotropy of the search ellipse was kept constant for the most 
strongly correlated elements (Ag, Cu, Pb, and Zn) and was related to the 
general orientation and range of the modelled variograms. For increasing 
estimation pass number, the size of the search ellipse was increased, and the 
minimum number of samples was decreased to ensure all blocks were interpolated. 
The maximum number of samples was calibrated to match the expected grade 
tonnage curve at the scale of future mining, this was to ensure that there was 
not excessive smoothing of the estimate. Top caps were applied to extreme 
values and for high-grade outlier values restricted search neighbourhoods were 
used. The restricted neighbourhoods ensured that high-grade outlier values only 
informed blocks in close proximity to the composite data, limiting the smearing 
of high-grade data. 
 
In order to assure the quality of the estimate, the block model was validated 
using statistical comparison, visual inspection and swath plot analysis. 
 
The density values were calculated using a linear regression of density versus 
the combined Cu, Pb, and Zn grade. 
 
Parys Mountain Classification and Reporting 
 
Clause 20 of the JORC (2012) Code requires that all reports of Mineral 
Resources must have Reasonable Prospects for Eventual Economic Extraction 
(RPEEE), regardless of the classification of the resource. The Parys Mountain 
deposit has reasonable prospects for eventual economic extraction on the 
following basis: 
 
  * Metallurgical test work by multiple consultants has confirmed that the 
    Parys Mountain mineralisation is amenable to flotation processes; 
  * The cut-off grade adopted for reporting (US$45.15/t NSR) is considered 
    reasonable given the Mineral Resource will most likely be exploited by 
    underground mining methods and processed using flotation techniques 
  * Operating costs for mining, processing and G&A were modelled at US$45.15/t 
    of mill feed; and, 
  * Minerals Resources were constrained by optimised stope shapes 
 
The Preliminary Economic Assessment (PEA) completed in 2021 demonstrated that 
the deposit potentially has a positive net present value (NPV), and that the 
mineralised zone is potentially mineable using underground methods under the 
given economic scenario and parameters. The PEA did not estimate Ore Reserves 
for the deposit. The deposit appears to have reasonable prospects of eventual 
economic extraction under a realistic set of criteria. 
 
The Parys Mountain Mineral Resource has been classified based on the guidelines 
specified in the JORC Code. The classification level is based upon an 
assessment of geological understanding of the deposit, geological and 
mineralisation continuity, drill hole spacing, QA/QC results, search and 
interpolation parameters and an analysis of available density information. The 
MRE is reported by classification in the tables above, and are constrained by 
5.0m (height) x 5.0m (width) x 20.0m (level interval) stope shapes dumped at an 
angle of 50° to the North above an NSR cut-off of US$45/t. 
 
Competent Person 
 
The information in this announcement which relates to the updated resource 
estimate for the Parys Mountain deposit has been approved by Mrs. Liz de Klerk, 
M.Sc., Pr.Sci.Nat., MIMMM who is a professional registered with the South 
African Council for Natural Scientific Professionals (SACNASP) and independent 
consultant to the Company. Mrs. de Klerk is the Senior Geologist & Managing 
Director of Micon International Co Limited and has over 20 continuous years of 
exploration and mining experience in a variety of mineral deposit styles. Mrs. 
de Klerk has sufficient experience which is relevant to the style of 
exploration, mineralisation and type of deposit under consideration and to the 
activity which she is undertaking to qualify as a Competent Person as defined 

in the 2012 Edition of the "Australasian Code for reporting of Exploration 
Results, Exploration Targets, Mineral Resources and Ore Reserves" (JORC Code). 
Mrs. de Klerk is also a "Qualified Person" as defined in the "Note for Mining 
and Oil & Gas Companies" which form part of the AIM Rules for Companies. Mrs. 
de Klerk has reviewed and consented to the inclusion in the announcement of the 
information in the form and context in which it appears. 
 
Glossary of Technical Terms 
 
"Ag"                   chemical symbol for silver 
 
"Au"                   chemical symbol for gold 
 
"Cu"                   the chemical symbol for copper 
 
"CuEq"                 copper equivalent 
 
"cut-off"              the lowest grade value that is included in a Resource 
                       statement. It must comply with JORC requirement 19: 
                       "reasonable prospects for eventual economic 
                       extraction" the lowest grade, or quality, of 
                       mineralised material that qualifies as economically 
                       mineable and available in a given deposit. It may be 
                       defined on the basis of economic evaluation, or on 
                       physical or chemical attributes that define an 
                       acceptable product specification 
 
"grade"                relative quantity or the percentage of ore mineral or 
                       metal content in an ore body 
 
"g/t"                  grammes per tonne, equivalent to parts per million 
 
"Inferred Resource"    that part of a Mineral Resource for which tonnage, 
                       grade and mineral content can be estimated with a low 
                       level of confidence. It is inferred from geological 
                       evidence and assumed but not verified geological and/ 
                       or grade continuity. It is based on information 
                       gathered through appropriate techniques from locations 
                       such as outcrops, trenches, pits, workings and drill 
                       holes which may be limited or of uncertain quality and 
                       reliability 
 
"Indicated Resource"   that part of a Mineral Resource for which tonnage, 
                       densities, shape, physical characteristics, grade and 
                       mineral content can be estimated with a reasonable 
                       level of confidence. It is based on exploration, 
                       sampling and testing information gathered through 
                       appropriate techniques from locations such as 
                       outcrops, trenches, pits, workings and drill holes. 
                       The locations are too widely or inappropriately spaced 
                       to confirm geological and/or grade continuity but are 
                       spaced closely enough for continuity to be assumed 
 
"JORC"                 The Australasian Joint Ore Reserves Committee Code for 
                       Reporting of Exploration Results, Mineral Resources 
                       and Ore Reserves 2012 (the "JORC Code" or "the Code"). 
                       The Code sets out minimum standards, recommendations 
                       and guidelines for Public Reporting in Australasia of 
                       Exploration Results, Mineral Resources and Ore 
                       Reserves 
 
"Measured Resource"    that part of a Mineral Resource for which tonnage, 
                       densities, shape, physical characteristics, grade and 
                       mineral content can be estimated with a high level of 
                       confidence. It is based on detailed and reliable 
                       exploration, sampling and testing information gathered 
                       through appropriate techniques from locations such as 
                       outcrops, trenches, pits, workings and drill holes. 
                       The locations are spaced closely enough to confirm 
                       geological and grade continuity 
 
"Mineral Resource"     a concentration or occurrence of material of intrinsic 
                       economic interest in or on the Earth's crust in such 
                       form, quality and quantity that there are reasonable 
                       prospects for eventual economic extraction. The 
                       location, quantity, grade, geological characteristics 
                       and continuity of a Mineral Resource are known, 
                       estimated or interpreted from specific geological 
                       evidence and knowledge. Mineral Resources are 
                       sub-divided, in order of increasing geological 
                       confidence, into Inferred, Indicated and Measured 
                       categories when reporting under JORC 
 
"MRE"                  mineral resource estimate 
 
"Mt"                   million tonnes 
 
"NSR"                  net smelter revenue 
 
"oz"                   troy ounce (= 31.103477 grammes) 
 
"Pb"                   the chemical symbol for lead 
 
"PEA"                  preliminary economic assessment 
 
"t"                    tonne (= 1 million grammes) 
 
"Zn"                   the chemical symbol for zinc 
 
"ZnEq"                 zinc equivalent 
 
A PDF version of this annoucement with additional diagrams can be viewed or 
downloaded via the following link:  https://www.angleseymining.co.uk/wp-content 
/uploads/2023/04/Parys_Mountain_Resource_Update.pdf 
 
About Anglesey Mining plc 
 
 
Anglesey Mining is traded on the AIM market of the London Stock Exchange and 
currently has 295,220,548 ordinary shares on issue. 
 
Anglesey is developing its 100% owned Parys Mountain Cu-Zn-Pb-Ag-Au deposit in 
North Wales, UK with a reported resource of 5.3 million tonnes at over 4.0% 
combined base metals in the Measured and Indicated categories and 10.8 million 
tonnes at over 2.5% combined base metals in the Inferred category. 
 
 
Anglesey also holds an almost 50% interest in the Grängesberg Iron project in 
Sweden, together with management rights and a right of first refusal to 
increase its interest to 100%.  Anglesey also holds 12% of Labrador Iron Mines 
Holdings Limited, which through its 52% owned subsidiaries, is engaged in the 
exploration and development of direct shipping iron ore deposits in Labrador 
and Quebec. 
 
 
 
 
For further information, please contact: 
 
 
Anglesey Mining plc 
 
Jo Battershill, Chief Executive - Tel: [phone] 
 
John Kearney, Chairman - Tel: [phone] 
 
Davy 
 
Nominated Adviser & Joint Corporate Broker 
 
Brian Garrahy / Daragh O'Reilly - Tel: [phone] 
 
WH Ireland 
 
Joint Corporate Broker 
 
Katy Mitchell / Harry Ansell - Tel: [phone] 
 
LEI: 213800X8BO8EK2B4HQ71 
 
 
 
END 
 
 

(END) Dow Jones Newswires

April 03, 2023 02:00 ET (06:00 GMT)