REG - Castillo Copper Ltd - Assays boosts confidence - exceptional 38.9% MREO
15/02/2023 07:16
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RNS Number : 9326P Castillo Copper Limited 15 February 2023
15 February 2023
CASTILLO COPPER LIMITED
("Castillo", or the "Company")
Diamond core TREO assay boosts confidence; exceptional 38.9% MREO
Castillo Copper Limited (LSE and ASX: CCZ), a base metal explorer primarily
focused on copper across Australia and Zambia, is delighted with the latest
assays results for the Tors Tank and Fence Gossan Prospects, as collectively
they materially increase confidence in the shallow, clay-hosted, Rare Earth
Element ("REE") discovery across the central part of the BHA Project's East
Zone (Appendix A).
HIGHLIGHTS:
· The assay results for diamond core from TT_005DD - undertaken at the
Tors Tank Prospect (refer Appendix A) - significantly boosts confidence in the
shallow, clay-hosted, rare-earth element discovery(1), with the best
intercept:
o 13m @ 1,550ppm Total Rare Earth Oxides ("TREO") from 5m
o Notably, high value Magnetic REO (Nd+Pr+Dy+Tb) represented an exceptional
38.9% of the TREO grade vs 25% peer average(2)
· Re-assays of 4m composite samples at Tors Tank and Fence Gossan to 1m
provided greater clarity on the underlying geology, whilst delivering further
evidence of an extensive, shallow REE mineralisation system - the best
intercepts comprise:
o 17m @ 1,605ppm TREO from 2m and 1m @ 3,236 TREO from 19m (FG_003RC)
o 10m @ 1,013ppm TREO from 49m (FG_001RC)
o 6m @ 1,480ppm TREO from 7m (FG_004RC)
o 5m @ 1,598ppm TREO from 14m (TT_002RC)
o 4m @ 1,342ppm TREO from 28m (FG_004RC)
o 2m @ 3,491ppm TREO from 7m (TT_003RC)
· Assays for circa 70% of the recent hand auger surface sampling
campaign across Fence Gossan delineated a sizeable 4.5km(2) anomalous area for
REE mineralisation:
o A preliminary interpretation suggests there are several more prime targets
to test-drill that could potentially extend known mineralisation between the
Fence Gossan and Tors Tank Prospects
· A fuller interpretation will be released once all the assay results
for the auger sampling campaign and drill-holes RT_002-004RC are received from
the laboratory
Dr Dennis Jensen, Managing Director of Castillo Copper, said: "The Board is
delighted with the latest results, especially the diamond core assay at Tors
Tank and exceptional MREO value, as it increases confidence in the underlying
REE system. In addition, the hand auger surface sampling campaign is proving
to be a treasure trove of insights, with several new targets now on the radar.
The Board looks forward to receiving the remaining assays and charting the
next phase of the exploration campaign."
ASSAYS BOOST REE CONFIDENCE AT BROKEN HILL
Diamond core
Drill-hole TT_005DD, which produced diamond core from the Tors Tank Prospect
(refer Figure 1), returned an excellent assay result, with the best intercept:
13m @ 1,550ppm TREO from 5m.
More significantly, the high value Magnetic REO, which comprises in-demand
REEs (Nd+Pr+Dy+Tb), represented an exceptional 38.9% of the TREO grade which
is well above the 25% average among the peer group(2).
FIGURE 1: TORS TANK DIAMOND CORE FROM 5.3-11.8M (TT_OO5DD)
Source: CCZ geology team
Re-assays: Tors Tank and Fence Gossan
To gain greater insights of the underlying geology at Tors Tank and Fence
Gossan, the 4m composite samples were re-assayed to 1m - with the best results
highlighted in Figure 2, with up to 3,491ppm TREO recorded. Interpreting the
re-assays provides clearer evidence that there is an extensive, shallow REE
mineralisation system across the centre of the BHA Project's East Zone (refer
Appendix A).
FIGURE 2: BEST "RC" INTERCEPTS TORS TANK / FENCE GOSSAN
Hole From (m) To (m) Width (m) TREO (ppm) MREO (%)
TT_001RC 25 27 2 1,048 27.1%
TT_002RC 14 19 5 1,598 29.1%
TT_003RC 4 11 7 890 34.6%
12 13 1 1,103 28.4%
15 17 2 3,491 24.6%
FG_001RC 8 20 12 907 31.0%
49 59 10 1,013 24.7%
FG_002RC 11 16 5 1,065 28.9%
FG_003RC 2 19 17 1,605 28.6%
19 20 1 3,236 28.9%
FG_004RC 7 13 6 1,480 28.9%
28 32 4 1,342 22.9%
Source: CCZ geology team
Surface sampling: Fence Gossan
Around 70% of the hand auger surface sampling assays for the Fence Gossan
Prospect have been returned. Pleasingly, the assays delineate a sizeable
(circa 4.5km(2)) anomalous REE zone - refer to Figure 3 below.
Surface readings indicate anomalous areas to the south, south-west and
north-west of the four recent cobalt-focussed Fence Gossan drill-holes which
suggest possible higher mineralisation in these zones than identified in the
drill-holes (Figure 3).
Having reconciled these findings and performed a statistical analysis, the
geology team believe surface sample readings with Ce > 100ppm is a likely
indicator of higher grade REE mineralisation at depth. As such, these are
interpreted to be prime targets for test-drilling that could extend known
mineralisation between the Tors Tank and Fence Gossan Prospects.
FIGURE 3: SURFACE MAPPED LITHOLOGY VS CERIUM CONTOURS (PPM)
Note: Coordinates in MGA94 - Z54; scale range cerium contours 20-230ppm.
Source: CCZ geology team / ALS Laboratory
For further information, please contact:
Castillo Copper Limited +61 8 6558 0886
Dr Dennis Jensen (Australia), Managing Director
Gerrard Hall (UK), Chairman
SI Capital Limited (Financial Adviser and Corporate Broker) +44 (0)1483 413500
Nick Emerson
Gracechurch Group (Financial PR) +44 (0)20 4582 3500
Harry Chathli, Alexis Gore, Henry Gamble
About Castillo Copper
Castillo Copper Limited is an Australian-based explorer primarily focused on
copper across Australia and Zambia. The group is embarking on a strategic
transformation to morph into a mid-tier copper group underpinned by its core
projects:
· A large footprint in the Mt Isa copper-belt district, north-west
Queensland, which delivers significant exploration upside through having
several high-grade targets and a sizeable untested anomaly within its
boundaries in a copper-rich region.
· Four high-quality prospective assets across Zambia's copper-belt
which is the second largest copper producer in Africa.
· A large tenure footprint proximal to Broken Hill's world-class
deposit that is prospective for zinc-silver-lead-copper-gold and platinoids.
· Cangai Copper Mine in northern New South Wales, which is one of
Australia's highest grading historic copper mines.
The group is listed on the LSE and ASX under the ticker "CCZ."
Competent Person's Statement
The information in this report that relates to Exploration Results and Mineral
Resource Estimates for "BHA Project, East Zone" is based on information
compiled or reviewed by Mr Mark Biggs. Mr Biggs is a director of ROM
Resources, a company which is a shareholder of Castillo Copper Limited. ROM
Resources provides ad hoc geological consultancy services to Castillo Copper
Limited. Mr Biggs is a member of the Australian Institute of Mining and
Metallurgy (member #107188) and has sufficient experience of relevance to the
styles of mineralisation and types of deposits under consideration, and to the
activities undertaken, to qualify as a Competent Person as defined in the 2012
Edition of the Joint Ore Reserves Committee (JORC) Australasian Code for
Reporting of Exploration Results, and Mineral Resources. Mr Biggs holds an
AusIMM Online Course Certificate in 2012 JORC Code Reporting. Mr Biggs also
consents to the inclusion in this report of the matters based on information
in the form and context in which it appears.
References
1) CCZ ASX Release - 23 November 2022
2) Nelson, S. "Rare earths rush showed no signs of abating in Q4
2022" 6 February 2023. Available at:
https://www.proactiveinvestors.com.au/companies/news/1005217/rare-earths-rush-showed-no-signs-of-abating-in-q4-2022-1005217.html
APPENDIX A: BHA PROJECT'S EAST ZONE
FIGURE A1: BHA PROJECT's EAST ZONE - REE EXPLORATION FOOTPRINT
Source: CCZ geology team
FIGURE A2: BHA PROJECT
Source: CCZ geology team
APPENDIX B: REE RESULTS / TREO CONVERSION FACTOR
FIGURE B1: TORS TANK / FENCE GOSSAN - 1M INTERSECTIONS >500PPM TREO
Hole From (m) To (m) Apparent Ag Th (ppm) U (ppm) TREO (ppm)1 TREO-Ce (ppm) LREO (ppm) HREO (ppm) CREO MREO
Width (m) (g/t) (%) (%)
FG_001RC 3 4 1 0.05 20.2 7.1 864 511.78 751.75 112.58 26.5% 30.1%
8 20 12 0.07 7.7 13.0 907 539.26 788.62 118.24 26.3% 31.0%
49 59 10 0.03 11.1 17.0 1,013 595.88 860.49 152.98 24.9% 24.7%
FG_002RC 3 5 2 0.11 8.2 10.7 637 363.49 554.22 83.20 24.5% 26.3%
6 10 4 0.07 15.6 7.1 711 411.55 622.39 88.89 24.2% 27.2%
11 16 5 0.02 8.8 17.6 1,065 643.95 910.78 154.51 26.7% 28.9%
FG_003RC 2 19 17 0.08 14.3 19.6 1,605 1011.78 1378.22 226.81 26.7% 28.6%
19 20 1 0.11 1.8 47.6 3,236 2441.30 2079.08 1156.99 40.3% 28.9%
59 60 1 0.04 8.7 25.1 808 546.46 632.71 175.40 31.3% 26.0%
FG_004RC 7 13 6 0.21 18.4 10.4 1,480 863.25 1299.89 179.81 25.2% 28.9%
28 32 4 0.13 19.4 28.2 1,342 762.43 1185.14 156.78 21.9% 22.9%
48 57 9 0.08 9.7 24.1 848 477.63 736.43 111.69 23.2% 24.3%
61 63 2 0.07 17.3 7.8 782 432.64 689.41 92.71 22.0% 23.4%
TT_001RC 25 27 2 0.17 4.3 15.7 1,048 755.07 668.01 380.03 41.0% 27.1%
39 40 1 0.05 19.2 1.7 752 396.02 705.28 46.97 20.1% 25.8%
41 42 1 0.04 22.0 1.9 624 310.71 583.08 40.87 19.6% 24.7%
43 44 1 0.04 9.0 3.8 747 437.58 677.48 69.66 23.7% 29.0%
47 48 1 0.09 19.6 3.2 684 374.60 627.57 56.59 18.2% 20.3%
49 51 2 0.07 32.5 3.6 676 379.43 595.53 80.57 22.5% 23.6%
TT_002RC 14 19 5 0.72 0.9 7.4 1,598 959.58 1235.37 363.60 31.5% 29.1%
TT_003RC 4 11 7 0.23 1.2 8.6 890 586.78 708.95 181.16 32.8% 34.6%
12 13 1 0.08 1.8 14.0 1,103 676.16 805.70 297.95 34.6% 28.4%
15 17 1 0.14 1.8 15.0 3,491 3072.18 1281.72 2209.34 59.3% 24.6%
TT_005DD 5 18 13 0.38 3.0 12.4 1,550 1150.56 1123.35 427.05 40.1% 38.9%
67 68 1 0.12 6.8 8.2 722 443.76 599.73 122.88 30.5% 31.2%
TT_004RC n/a n/a
Notes:
1. TT_001RC 39-52m composite also reports 6,388 ppm Ba (Barium);
TT_003RC 1,140 ppm Ba.
2. Two of the Lanthanum (La) assay from FG_003R returned >500ppm
were re-analysed (514 and 527ppm, respectively).
3. Verification has been undertaken by ROM Resources personnel.
4. Sample results from ALS method ME-ICP81.
Source: ALS Adelaide
TREO conversion factor
Conversion of elemental analysis (REE parts per million) to stoichiometric
oxide (REO parts per million) was undertaken by ROM geological staff using the
below (Figure B2) element to stoichiometric oxide conversion factors.
FIGURE B2: ELEMENT - CONVERSION FACTOR - OXIDE FORM
Rare Earth Element Factor for Conversion Rare Earth Oxide Common Form
Ce 1.2284 CeO(2)
Dy 1.1477 Dy(2)O(3)
Er 1.1435 Er(2)O(3)
Eu 1.1579 Eu(2)O(3)
Gd 1.1526 Gd(2)O(3)
Ho 1.1455 Ho(2)O(3)
La 1.1728 La(2)O(3)
Lu 1.1371 Lu(2)O(3)
Nd 1.1664 Nd(2)O(3)
Pr 1.2083 Pr(6)O(11)
Sm 1.1596 Sm(2)O(3)
Tb 1.1762 Tb(4)O(7)
Tm 1.1421 Tm(2)O(3)
Y 1.2699 Y(2)O(3)
Yb 1.1387 Yb(2)O(3)
Source: CCZ geology team
Rare earth oxide is the industry accepted form for reporting rare earths. The
following calculations are used for compiling REO into their reporting and
evaluation groups:
· TREO (Total Rare Earth Oxide) = La(2)O(3) + CeO(2) + Pr(6)O(11) +
Nd(2)O(3) + Sm(2)O(3) + Eu(2)O(3) + Gd(2)O(3) + Tb(4)O(7) + Dy(2)O(3) +
Ho(2)O(3) + Er(2)O(3) + Tm(2)O(3) + Yb(2)O(3) + Y(2)O3 + Lu(2)O(3).
· TREO-Ce = TREO - CeO(2)
· LREO (Light Rare Earth Oxide) = La(2)O(3) + CeO(2) + Pr(6)O(11) +
Nd(2)O(3) + Sm(2)O(3)
· HREO (Heavy Rare Earth Oxide) = Eu(2)O(3) + Gd(2)O(3) + Tb(4)O(7) +
Dy(2)O(3) + Ho(2)O(3) + Er(2)O(3) + Tm(2)O(3) + Yb(2)O(3) + Y(2)O(3) +
Lu(2)O(3)
· CREO (Critical Rare Earth Oxide) = Nd(2)O(3) + Eu(2)O(3) + Tb(4)O(7)
+ Dy(2)O(3) + Y(2)O(3)
· MREO (Magnetic Rare Earth Oxide) = Pr(6)O(11) + Nd(2)O(3) + Sm(2)O(3)
+ Gd(2)O(3) + Tb(4)O(7) + Dy(2)O(3).
Total Rare Earth Oxides (TREO):
To calculate TREO an oxide conversion "factor" is applied to each rare-earth
element assay.
The "factor" equates an elemental assay to an oxide concentration for each
element. Below is an example of the factor calculation for Lanthanum (La).
Relative Atomic Mass (La) = 138.9055
Relative Atomic Mass (O) = 15.9994
Oxide Formula = La(2)O(3)
Oxide Conversion Factor = 1/ ((2x 138.9055)/(2x 138.9055 + 3x 15.9994)) Oxide
Conversion Factor = 1.173 (3 decimal places)
APPENDIX C: DRILLHOLE COORDINATES AFTER SURVEY
All drill-holes have now been surveyed, with coordinates showing only 0.5-4m
errors in X and Y compared to the initial GPS readings (Figures C1-3). The
total program consisted of 1,568m of RC and 137.7m of HQ diamond core.
FIGURE C1: TORS TANK SURVEYED DRILL COLLARS
HoleID Easting (GDA94) Northing (GDA94) AHD (m) TDepth (m) Grid Azimuth Dip Horizontal Hole Type Start End
TT_001RC 571356 6451399 191.2 120 193.1 -63.1 RC 30-Sep-22 1-Oct-22
TT_002RC 571473 6451248 191.4 108 188.6 -63.0 RC 1-Oct-22 2-Oct-22
TT_003RC 571421 6451278 193.1 140 192.1 -62.5 RC 2-Oct-22 3-Oct-22
TT_004RC 571230 6451498 189.9 120 186.8 -66.1 RC 3-Oct-22 4-Oct-22
TT_005DD 571427 6451276 193.0 137.7 187.2 -60.8 DDH 11-Oct-22 17-Oct-22
625.7
Source: CCZ geology team
FIGURE C2: FENCE GOSSAN SURVEYED DRILL COLLARS
HoleID Easting (GDA94) Northing (GDA94) AHD (m) Tdepth (m) Grid Azimuth DipH Hole Type Start End
FG_001RC 576347 6453786 171.2 126 191.8 -64.9 RC 4-Oct-22 7-Oct-22
FG_002RC 576547 6453751 169.1 110 195.2 -65.2 RC 7-Oct-22 8-Oct-22
FG_003RC 576696 6453833 167.7 160 193.7 -67.9 RC 8-Oct-22 9-Oct-22
FG_004RC 575998 6453831 173.7 120 188.2 -64.2 RC 9-Oct-22 10-Oct-22
516
Source: CCZ geology team
FIGURE C3: REEFS TANK SURVEYED DRILL COLLARS
HoleID Easting Northing AHD (m) TD Azimuth DipH Type Start Finish
RT_001RC 574106.703 6456242.501 179.7 120 188.0 -62.1 RC 10/10/2022 11/10/2022
RT_002RC 574120.601 6455468.441 188.1 204 189.2 -65.3 RC 9/11/2022 10/11/2022
RT_003RC 573418.409 6455244.784 191.7 120 186.4 -63.7 RC 10/11/2022 14/11/2022
RT_004RC 573726.282 6454924.984 186.6 120 190.2 -61.5 RC 14/11/2022 15/11/2022
564
Source: CCZ geology team
Figures C4 and C5 show a cross-section of the extent of downhole distribution
of cobalt and cerium at Tors Tank. Most of the major occurrences are at
<50m depth.
FIGURE C4: TORS TANK - COBALT (PPM)
Notes:
1. View looking north-west.
2. Vertical exaggeration 2:1
Source: CCZ geology team
FIGURE C5: TORS TANK CERIUM (PPM)
Source: CCZ geology team
At Fence Gossan, a downhole cross-section shows the distribution of the rare
earth element cerium (ppm), especially highlighting the anomalous zones near
surface and a second zone at about 50m depth. The high REE zones appear in
extremely weathered clays derived from mostly pegmatite.
FIGURE C6: FENCE GOSSAN CERIUM (PPM)
Source: CCZ geology team
APPENDIX D: JORC CODE, 2012 EDITION - TABLE 1
Section 1: Sampling Techniques and Data
Criteria JORC Code explanation Commentary
Sampling techniques Nature and quality of sampling (e.g., cut channels, random chips, or specific Diamond Drilling (DDH)
specialised industry standard measurement tools appropriate to the minerals
under investigation, such as down hole gamma sondes, or handheld XRF Diamond drilling of HQ diameter (TT_005DD) was completed to 137.7m recently in
instruments, etc.). These examples should not be taken as limiting the broad the completed program and was located 5m away from a RC hole already drilled
meaning of sampling. (TT_003RC).
Include reference to measures taken to ensure sample representivity and the Reverse Circulation ('RC') Drilling
appropriate calibration of any measurement tools or systems used.
RC drilling at Fence Gossan was used to obtain a representative sample by
Aspects of the determination of mineralisation that are Material to the Public means of riffle splitting with samples submitted for analysis using the
Report. above-mentioned methodologies.
In cases where 'industry standard' work has been done this would be relatively Four (4) reverse circulation (RC) holes for a total of 516m have been
simple (e.g., 'reverse circulation drilling was used to obtain 1 m samples completed at the Fence Gossan Prospect.
from which 3 kg was pulverised to produce a 30g charge for fire assay'). In
other cases, more explanation may be required, such as where there is coarse Four (4) RC holes were completed at Reefs Tank for a total of 564m.
gold that has inherent sampling problems. Unusual commodities or
mineralisation types (eg submarine nodules) may warrant disclosure of detailed At Tors Tank, four (4) RC holes for a total of 625.7m (including the cored
information. hole) were completed.
The RC drilling technique was used to obtain a representative sample by means
of a cone or riffle splitter with samples submitted for assay by mixed acid
digestion and analysis via ICP-MS + ICP-AES with anticipated reporting a suite
of 48 elements (sulphur >10% by LECO).
Drilling techniques Drill type (e.g., core, reverse circulation, open-hole hammer, rotary air Historical drilling consisted of auger, rotary air blast, reverse circulation,
blast, auger, Bangka, sonic, etc.) and details (e.g. core diameter, triple or and NQ, BQ, and HQ diamond coring. One cored hole of HQ (61mm) diameter was
standard tube, depth of diamond tails, face-sampling bit or other type, completed at Tors Tank after all the RC holes had been completed.
whether core is oriented and if so, by what method, etc.).
Diamond drilling will be completed with standard diameter, conventional HQ and
NQ with historical holes typically utilizing RC and percussion pre-collars to
an average 30 metres (see Drillhole Information for further details).
Drill sample recovery Method of recording and assessing core and chip sample recoveries and results Reverse Circulation ('RC') Drilling - Reverse circulation sample recoveries
assessed. were visually estimated during drilling programs. Where the estimated sample
recovery was below 100% this was recorded in field logs by means of
Measures taken to maximise sample recovery and ensure representative nature of qualitative observation.
the samples.
Reverse circulation drilling employed sufficient air (using a compressor and
Whether a relationship exists between sample recovery and grade and whether booster) to maximise sample recovery.
sample bias may have occurred due to preferential loss/gain of fine/coarse
material. Historical cored drillholes by North Broken Hill, CRA , and Pasminco were well
documented and generally have >90% core recovery.
No relationship between sample recovery and grade has been observed.
Logging Whether core and chip samples have been geologically and geotechnically logged The drilling that did occur was completed to modern-day standards. The
to a level of detail to support appropriate Mineral Resource estimation, preferred exploration strategy in the eighties and early nineties was to drill
mining studies and metallurgical studies. shallow auger holes to negate the influence of any Quaternary and Tertiary
sedimentary cover, and then return to sites where anomalous Cu or Zn were
Whether logging is qualitative or quantitative in nature. Core (or costean, assayed. In this program at all three areas holes were completed to varying
channel, etc) photography. depths ranging from 100-160m.
The total length and percentage of the relevant intersections logged. No downhole geophysical logging took place; however, measurements of magnetic
susceptibility were taken at the same 1m intervals as the PXRF readings were
taken.
Sub-sampling techniques and sample preparation If core, whether cut or sawn and whether quarter, half or all core taken. Core samples will be hand-split or sawn with re-logging of available
historical core indicating a 70:30 (retained: assayed) split was typical. The
If non-core, whether riffled, tube sampled, rotary split, etc and whether variation of sample ratios noted are considered consistent with the
sampled wet or dry. sub-sampling technique (hand-splitting).
For all sample types, the nature, quality, and appropriateness of the sample No second half samples will be submitted for analysis, but duplicates have
preparation technique. been taken at a frequency of 1:20 in samples collected.
Quality control procedures adopted for all sub-sampling stages to maximise It is considered water planned to be used for core cutting is unprocessed and
representivity of samples. unlikely to have introduced sample contamination.
Measures taken to ensure that the sampling is representative of the in-situ Procedures relating to the definition of the line of cutting or splitting are
material collected, including for instance results for field not available. It is expected that 'standard industry practice' for the
duplicate/second-half sampling. period was applied to maximize sample representivity.
Whether sample sizes are appropriate to the grain size of the material being Quarter core will be submitted to ALS for chemical analysis using industry
sampled. standard sample preparation and analytical techniques.
The sample interval details and grades quoted for cored intervals described in
various maps in the main section are given in previous ASX releases (Castillo
Copper 2022a, b, c, d, e, f).
Quality of assay data and laboratory tests The nature, quality and appropriateness of the assaying and laboratory The following rare earth elements were analysed using ME-MS61R Sample
procedures used and whether the technique is considered partial or total. Decomposition is by HF-HNO(3)-HClO(4) acid digestion, HCl leach (GEO-4A01).
The Analytical Method for
For geophysical tools, spectrometers, handheld XRF instruments, etc, the
parameters used in determining the analysis including instrument make and
model, reading times, calibrations factors applied and their derivation, etc.
Silver is shown below:
Nature of quality control procedures adopted (eg standards, blanks,
Element Symbol Units Lower Limit Upper Limit
duplicates, external laboratory checks) and whether acceptable levels of Silver Ag ppm 0.01 100
accuracy (i.e. lack of bias) and precision have been established.
Inductively Coupled Plasma - Atomic Emission Spectroscopy (ICP - AES)
Inductively Coupled Plasma - Mass Spectrometry (ICP-MS)
Aprepared sample (0.25 g) is digested with perchloric, nitric, hydrofluoric,
and hydrochloric acids. The residue is topped up with dilute hydrochloric acid
and analysed by inductively coupled plasma atomic emission spectrometry.
Following this analysis, the results are reviewed for high concentrations of
bismuth, mercury, molybdenum, silver, and tungsten and diluted accordingly.
Samples meeting this criterion are then analysed by inductively coupled
plasma-mass spectrometry. Results are corrected for spectral interelement
interferences.
Four acid digestions can dissolve most minerals: however, although the term
"near total" is used, depending on the sample matrix, not all elements are
quantitatively extracted.
Results for the additional rare earth elements will represent the acid
leachable portion of the rare earth elements and as such, cannot be used, for
instance to do a chondrite plot.
Geochemical Procedure
Element geochemical procedure reporting units and limits are listed below:
Element Symbol Units Lower Limit Upper Limit
Molybdenum Mo ppm 0.05 10 000
Sodium Na % 0.01 10
Niobium Nb ppm 0.1 500
Nickel Ni ppm 0.2 10 000
Phosphorous P ppm 10 10 000
Lead Pb ppm 0.5 10 000
Rubidium Rb ppm 0.1 10 000
Rhenium Re ppm 0.002 50
Sulphur S % 0.01 10
Antimony Sb ppm 0.05 10 000
Scandium Sc ppm 0.1 10 000
Selenium Se ppm 1 1 000
Tin Sn ppm 0.2 500
Strontium Sr ppm 0.2 10 000
Tantalum Ta ppm 0.05 100
Tellurium Te ppm 0.05 500
Thorium Th ppm 0.2 10 000
Titanium Ti % 0.005 10
Thallium Tl ppm 0.02 10 000
Uranium U ppm 0.1 10 000
Vanadium V ppm 1 10 000
Tungsten W ppm 0.1 10 000
Element Symbol Units Lower Limit Upper Limit
Yttrium Y ppm 0.1 500
Zinc Zn ppm 2 10 000
Zirconium Zr ppm 0.5 500
Dysprosium Dy ppm 0.05 1 000
Erbium Er ppm 0.03 1 000
Europium Eu ppm 0.03 1 000
Gadolinium Gd ppm 0.05 1 000
Holmium Ho ppm 0.01 1 000
Lutetium Lu ppm 0.01 1 000
Neodymium Nd ppm 0.1 1 000
Praseodymium Pr ppm 0.03 1 000
Samarium Sm ppm 0.03 1 000
Terbium Tb ppm 0.01 1 000
Thulium Tm ppm 0.01 1 000
Ytterbium Yb ppm 0.03 1 000
Inductively Coupled Plasma - Atomic Emission Spectroscopy (ICP - AES)
Inductively Coupled Plasma - Mass Spectrometry (ICP-MS)
A prepared sample (0.25 g) is digested with perchloric, nitric, hydrofluoric,
and hydrochloric acids. The residue is topped up with dilute hydrochloric acid
and analysed by inductively coupled plasma atomic emission spectrometry.
Following this analysis, the results are reviewed for high concentrations of
bismuth, mercury, molybdenum, silver, and tungsten and diluted accordingly.
Samples meeting this criterion are then analysed by inductively coupled
plasma-mass spectrometry. Results are corrected for spectral interelement
interferences.
Four acid digestions can dissolve most minerals: however, although the term
"near total" is used, depending on the sample matrix, not all elements are
quantitatively extracted.
Results for the additional rare earth elements will represent the acid
leachable portion of the rare earth elements and as such, cannot be used, for
instance to do a chondrite plot.
Geochemical Procedure
Element geochemical procedure reporting units and limits are listed below:
Element Symbol Units Lower Limit Upper Limit
Molybdenum Mo ppm 0.05 10 000
Sodium Na % 0.01 10
Niobium Nb ppm 0.1 500
Nickel Ni ppm 0.2 10 000
Phosphorous P ppm 10 10 000
Lead Pb ppm 0.5 10 000
Rubidium Rb ppm 0.1 10 000
Rhenium Re ppm 0.002 50
Sulphur S % 0.01 10
Antimony Sb ppm 0.05 10 000
Scandium Sc ppm 0.1 10 000
Selenium Se ppm 1 1 000
Tin Sn ppm 0.2 500
Strontium Sr ppm 0.2 10 000
Tantalum Ta ppm 0.05 100
Tellurium Te ppm 0.05 500
Thorium Th ppm 0.2 10 000
Titanium Ti % 0.005 10
Thallium Tl ppm 0.02 10 000
Uranium U ppm 0.1 10 000
Vanadium V ppm 1 10 000
Tungsten W ppm 0.1 10 000
Element Symbol Units Lower Limit Upper Limit
Yttrium Y ppm 0.1 500
Zinc Zn ppm 2 10 000
Zirconium Zr ppm 0.5 500
Dysprosium Dy ppm 0.05 1 000
Erbium Er ppm 0.03 1 000
Europium Eu ppm 0.03 1 000
Gadolinium Gd ppm 0.05 1 000
Holmium Ho ppm 0.01 1 000
Lutetium Lu ppm 0.01 1 000
Neodymium Nd ppm 0.1 1 000
Praseodymium Pr ppm 0.03 1 000
Samarium Sm ppm 0.03 1 000
Terbium Tb ppm 0.01 1 000
Thulium Tm ppm 0.01 1 000
Ytterbium Yb ppm 0.03 1 000
Element Symbol Units Lower Limit Upper Limit
Aluminum Al % 0.01 50
Arsenic As ppm 0.2 10 000
Barium Ba ppm 10 10 000
Beryllium Be ppm 0.05 1 000
Bismuth Bi ppm 0.01 10 000
Calcium Ca % 0.01 50
Cadmium Cd ppm 0.02 1 000
Cerium Ce ppm 0.01 500
Cobalt Co ppm 0.1 10 000
Chromium Cr ppm 1 10 000
Cesium Cs ppm 0.05 500
Copper Cu ppm 0.2 10 000
Iron Fe % 0.01 50
Gallium Ga ppm 0.05 10 000
Germanium Ge ppm 0.05 500
Hafnium Hf ppm 0.1 500
Indium In ppm 0.005 500
Potassium K % 0.01 10
Lanthanum La ppm 0.5 10 000
Lithium Li ppm 0.2 10 000
Magnesium Mg % 0.01 50
Manganese Mn ppm 5 100 000
Laboratory inserted standards, blanks and duplicates were analysed per
industry standard practice. There was no evidence of bias from these
results.
Verification of sampling and assaying The verification of significant intersections by either independent or · None of the drillholes have been twinned, as they are historical
alternative company personnel. holes.
The use of twinned holes. · Conversion of elemental analysis (REE parts per million) to
stoichiometric oxide (REO parts per million) was undertaken by ROM geological
Documentation of primary data, data entry procedures, data verification, data staff using the below (Table D1-1) element to stoichiometric oxide conversion
storage (physical and electronic) protocols. factors
(https://www.jcu.edu.au/news/releases/2020/march/rare-earth-metals-an-untapped-resource
Discuss any adjustment to assay data. (https://www.jcu.edu.au/news/releases/2020/march/rare-earth-metals-an-untapped-resource)
)
Table D1-1: Element -Conversion Factor -Oxide Form
Ce 1.2284 CeO2
Dy 1.1477 Dy2O3
Er 1.1435 Er2O3
Eu 1.1579 Eu2O3
Gd 1.1526 Gd2O3
Ho 1.1455 Ho2O3
La 1.1728 La2O3
Lu 1.1371 Lu2O3
Nd 1.1664 Nd2O3
Pr 1.2083 Pr6O11
Sm 1.1596 Sm2O3
Tb 1.1762 Tb4O7
Tm 1.1421 Tm2O3
Y 1.2699 Y2O3
Yb 1.1387 Yb2O3
Rare earth oxide is the industry accepted form for reporting rare earths. The
following calculations are used for compiling REO into their reporting and
evaluation groups:
TREO (Total Rare Earth Oxide) = La2O3 + CeO2 + Pr6O11 + Nd2O3 + Sm2O3 + Eu2O3
+ Gd2O3 + Tb4O7 + Dy2O3 + Ho2O3 + Er2O3 + Tm2O3 + Yb2O3 + Y2O3 + Lu2O3.
TREO-Ce = TREO - CeO2
LREO (Light Rare Earth Oxide) = La2O3 + CeO2 + Pr6O11 + Nd2O3 + Sm2O3
HREO (Heavy Rare Earth Oxide) = Eu2O3 + Gd2O3 + Tb4O7 + Dy2O3 + Ho2O3 + Er2O3
+ Tm2O3 + Yb2O3 + Y2O3 + Lu2O3
CREO (Critical Rare Earth Oxide) = Nd2O3 + Eu2O3 + Tb4O7 + Dy2O3 + Y2O3
MREO (Magnetic Rare Earth Oxide) = Pr6O11 + Nd2O3 + Sm2O3 + Gd2O3 + Tb4O7 +
Dy2O3.
Total Rare Earth Oxides (TREO):
To calculate TREO an oxide conversion "factor" is applied to each rare-earth
element assay. The "factor" equates an elemental assay to an oxide
concentration for each element. Below is an example of the factor calculation
for Lanthanum (La):
o Relative Atomic Mass (La) = 138.9055
o Relative Atomic Mass (O) = 15.9994
o Oxide Formula = La(2)O(3)
o Oxide Conversion Factor = 1/ ((2x 138.9055)/(2x 138.9055 + 3x 15.9994))
Oxide Conversion Factor = 1.173 (3dp)
None of the historical data has been adjusted.
Location of data points Accuracy and quality of surveys used to locate drill holes (collar and In general, locational accuracy does vary, depending upon whether the
down-hole surveys), trenches, mine workings and other locations used in historical surface and drillhole samples were digitised off plans or had their
Mineral Resource estimation. coordinated tabulated. Many samples were originally reported to AGD66 or
AMG84 and have been converted to MGA94 (Zone 54)
Specification of the grid system used.
The holes are currently surveyed with handheld GPS, awaiting more accurate
Quality and adequacy of topographic control. DGPS survey. It is thus estimated that locational accuracy therefore varies
between 2-4m until the more accurate surveying is completed. This assessment
was confirmed once the holes were surveyed by DGPS from GMC Surveying.
The quality of topographic control (GSNSW 1 sec DEM) is deemed adequate for
the purposes of the exploration drilling program.
Data spacing and distribution Data spacing for reporting of Exploration Results. The average sample spacing from the current drilling program across the tenure
varies per prospect, and sample type, as listed in Table D1-2, below:
Whether the data spacing and distribution is sufficient to establish the
degree of geological and grade continuity appropriate for the Mineral Resource Table D1-2: EL 8434 Drillhole Spacing
and Ore Reserve estimation procedure(s) and classifications applied.
Prospect Drillholes Completed RMS Drillhole Spacing (m)
The Sisters Not yet
Whether sample compositing has been applied. Iron Blow Not Yet
Tors Tank 4 127
Fence Gossan 4 208
Ziggy's Hill n/a n/a
Reefs Tank 1
The Datamine software allows creation of fixed length samples from the
original database given a set of stringent rules.
Orientation of data in relation to geological structure Whether the orientation of sampling achieves unbiased sampling of possible Historical drill holes at the BHAE are typically drilled vertically for auger
structures and the extent to which this is known, considering the deposit and RAB types (drilled along section lines) and angled at -55˚ or -60˚ to
type. the horizontal and drilled perpendicular to the mineralised trend for RC and
DDH (Figure D1-3 and D1-4).
If the relationship between the drilling orientation and the orientation of
key mineralised structures is considered to have introduced a sampling bias, Drilling orientations are adjusted along strike to accommodate folded
this should be assessed and reported if material. geological sequences. All Fence Gossan holes were designed to drill toward
grid south at an inclination of 60 degrees from horizontal.
The drilling orientation is not considered to have introduced a sampling bias
on assessment of the current geological interpretation.
Geological mapping by various companies has reinforced that the strata dips
variously between 5 and 65 degrees.
Sample security The measures taken to ensure sample security. Sample security procedures are considered 'industry standard' for the current
period.
Samples obtained during drilling completed between 4/10/22 to the 10/10/22
were transported by exploration employees or an independent courier directly
from Broken Hill to ALS Laboratory, Adelaide.
The Company considers that risks associated with sample security are limited
given the nature of the targeted mineralisation.
Audits or reviews The results of any audits or reviews of sampling techniques and data. No external audits or reviews have yet been undertaken.
Inductively Coupled Plasma - Atomic Emission Spectroscopy (ICP - AES)
Inductively Coupled Plasma - Mass Spectrometry (ICP-MS)
A prepared sample (0.25 g) is digested with perchloric, nitric, hydrofluoric,
and hydrochloric acids. The residue is topped up with dilute hydrochloric acid
and analysed by inductively coupled plasma atomic emission spectrometry.
Following this analysis, the results are reviewed for high concentrations of
bismuth, mercury, molybdenum, silver, and tungsten and diluted accordingly.
Samples meeting this criterion are then analysed by inductively coupled
plasma-mass spectrometry. Results are corrected for spectral interelement
interferences.
Four acid digestions can dissolve most minerals: however, although the term
"near total" is used, depending on the sample matrix, not all elements are
quantitatively extracted.
Results for the additional rare earth elements will represent the acid
leachable portion of the rare earth elements and as such, cannot be used, for
instance to do a chondrite plot.
Geochemical Procedure
Element geochemical procedure reporting units and limits are listed below:
Element Symbol Units Lower Limit Upper Limit
Molybdenum Mo ppm 0.05 10 000
Sodium Na % 0.01 10
Niobium Nb ppm 0.1 500
Nickel Ni ppm 0.2 10 000
Phosphorous P ppm 10 10 000
Lead Pb ppm 0.5 10 000
Rubidium Rb ppm 0.1 10 000
Rhenium Re ppm 0.002 50
Sulphur S % 0.01 10
Antimony Sb ppm 0.05 10 000
Scandium Sc ppm 0.1 10 000
Selenium Se ppm 1 1 000
Tin Sn ppm 0.2 500
Strontium Sr ppm 0.2 10 000
Tantalum Ta ppm 0.05 100
Tellurium Te ppm 0.05 500
Thorium Th ppm 0.2 10 000
Titanium Ti % 0.005 10
Thallium Tl ppm 0.02 10 000
Uranium U ppm 0.1 10 000
Vanadium V ppm 1 10 000
Tungsten W ppm 0.1 10 000
Element Symbol Units Lower Limit Upper Limit
Yttrium Y ppm 0.1 500
Zinc Zn ppm 2 10 000
Zirconium Zr ppm 0.5 500
Dysprosium Dy ppm 0.05 1 000
Erbium Er ppm 0.03 1 000
Europium Eu ppm 0.03 1 000
Gadolinium Gd ppm 0.05 1 000
Holmium Ho ppm 0.01 1 000
Lutetium Lu ppm 0.01 1 000
Neodymium Nd ppm 0.1 1 000
Praseodymium Pr ppm 0.03 1 000
Samarium Sm ppm 0.03 1 000
Terbium Tb ppm 0.01 1 000
Thulium Tm ppm 0.01 1 000
Ytterbium Yb ppm 0.03 1 000
Element Symbol Units Lower Limit Upper Limit
Aluminum Al % 0.01 50
Arsenic As ppm 0.2 10 000
Barium Ba ppm 10 10 000
Beryllium Be ppm 0.05 1 000
Bismuth Bi ppm 0.01 10 000
Calcium Ca % 0.01 50
Cadmium Cd ppm 0.02 1 000
Cerium Ce ppm 0.01 500
Cobalt Co ppm 0.1 10 000
Chromium Cr ppm 1 10 000
Cesium Cs ppm 0.05 500
Copper Cu ppm 0.2 10 000
Iron Fe % 0.01 50
Gallium Ga ppm 0.05 10 000
Germanium Ge ppm 0.05 500
Hafnium Hf ppm 0.1 500
Indium In ppm 0.005 500
Potassium K % 0.01 10
Lanthanum La ppm 0.5 10 000
Lithium Li ppm 0.2 10 000
Magnesium Mg % 0.01 50
Manganese Mn ppm 5 100 000
Laboratory inserted standards, blanks and duplicates were analysed per
industry standard practice. There was no evidence of bias from these
results.
Verification of sampling and assaying
The verification of significant intersections by either independent or
alternative company personnel.
The use of twinned holes.
Documentation of primary data, data entry procedures, data verification, data
storage (physical and electronic) protocols.
Discuss any adjustment to assay data.
· None of the drillholes have been twinned, as they are historical
holes.
· Conversion of elemental analysis (REE parts per million) to
stoichiometric oxide (REO parts per million) was undertaken by ROM geological
staff using the below (Table D1-1) element to stoichiometric oxide conversion
factors
(https://www.jcu.edu.au/news/releases/2020/march/rare-earth-metals-an-untapped-resource
(https://www.jcu.edu.au/news/releases/2020/march/rare-earth-metals-an-untapped-resource)
)
Table D1-1: Element -Conversion Factor -Oxide Form
Ce 1.2284 CeO2
Dy 1.1477 Dy2O3
Er 1.1435 Er2O3
Eu 1.1579 Eu2O3
Gd 1.1526 Gd2O3
Ho 1.1455 Ho2O3
La 1.1728 La2O3
Lu 1.1371 Lu2O3
Nd 1.1664 Nd2O3
Pr 1.2083 Pr6O11
Sm 1.1596 Sm2O3
Tb 1.1762 Tb4O7
Tm 1.1421 Tm2O3
Y 1.2699 Y2O3
Yb 1.1387 Yb2O3
Rare earth oxide is the industry accepted form for reporting rare earths. The
following calculations are used for compiling REO into their reporting and
evaluation groups:
TREO (Total Rare Earth Oxide) = La2O3 + CeO2 + Pr6O11 + Nd2O3 + Sm2O3 + Eu2O3
+ Gd2O3 + Tb4O7 + Dy2O3 + Ho2O3 + Er2O3 + Tm2O3 + Yb2O3 + Y2O3 + Lu2O3.
TREO-Ce = TREO - CeO2
LREO (Light Rare Earth Oxide) = La2O3 + CeO2 + Pr6O11 + Nd2O3 + Sm2O3
HREO (Heavy Rare Earth Oxide) = Eu2O3 + Gd2O3 + Tb4O7 + Dy2O3 + Ho2O3 + Er2O3
+ Tm2O3 + Yb2O3 + Y2O3 + Lu2O3
CREO (Critical Rare Earth Oxide) = Nd2O3 + Eu2O3 + Tb4O7 + Dy2O3 + Y2O3
MREO (Magnetic Rare Earth Oxide) = Pr6O11 + Nd2O3 + Sm2O3 + Gd2O3 + Tb4O7 +
Dy2O3.
Total Rare Earth Oxides (TREO):
To calculate TREO an oxide conversion "factor" is applied to each rare-earth
element assay. The "factor" equates an elemental assay to an oxide
concentration for each element. Below is an example of the factor calculation
for Lanthanum (La):
o Relative Atomic Mass (La) = 138.9055
o Relative Atomic Mass (O) = 15.9994
o Oxide Formula = La(2)O(3)
o Oxide Conversion Factor = 1/ ((2x 138.9055)/(2x 138.9055 + 3x 15.9994))
Oxide Conversion Factor = 1.173 (3dp)
None of the historical data has been adjusted.
Location of data points
Accuracy and quality of surveys used to locate drill holes (collar and
down-hole surveys), trenches, mine workings and other locations used in
Mineral Resource estimation.
Specification of the grid system used.
Quality and adequacy of topographic control.
In general, locational accuracy does vary, depending upon whether the
historical surface and drillhole samples were digitised off plans or had their
coordinated tabulated. Many samples were originally reported to AGD66 or
AMG84 and have been converted to MGA94 (Zone 54)
The holes are currently surveyed with handheld GPS, awaiting more accurate
DGPS survey. It is thus estimated that locational accuracy therefore varies
between 2-4m until the more accurate surveying is completed. This assessment
was confirmed once the holes were surveyed by DGPS from GMC Surveying.
The quality of topographic control (GSNSW 1 sec DEM) is deemed adequate for
the purposes of the exploration drilling program.
Data spacing and distribution
Data spacing for reporting of Exploration Results.
Whether the data spacing and distribution is sufficient to establish the
degree of geological and grade continuity appropriate for the Mineral Resource
and Ore Reserve estimation procedure(s) and classifications applied.
Whether sample compositing has been applied.
The average sample spacing from the current drilling program across the tenure
varies per prospect, and sample type, as listed in Table D1-2, below:
Table D1-2: EL 8434 Drillhole Spacing
Prospect Drillholes Completed RMS Drillhole Spacing (m)
The Sisters Not yet
Iron Blow Not Yet
Tors Tank 4 127
Fence Gossan 4 208
Ziggy's Hill n/a n/a
Reefs Tank 1
The Datamine software allows creation of fixed length samples from the
original database given a set of stringent rules.
Orientation of data in relation to geological structure
Whether the orientation of sampling achieves unbiased sampling of possible
structures and the extent to which this is known, considering the deposit
type.
If the relationship between the drilling orientation and the orientation of
key mineralised structures is considered to have introduced a sampling bias,
this should be assessed and reported if material.
Historical drill holes at the BHAE are typically drilled vertically for auger
and RAB types (drilled along section lines) and angled at -55˚ or -60˚ to
the horizontal and drilled perpendicular to the mineralised trend for RC and
DDH (Figure D1-3 and D1-4).
Drilling orientations are adjusted along strike to accommodate folded
geological sequences. All Fence Gossan holes were designed to drill toward
grid south at an inclination of 60 degrees from horizontal.
The drilling orientation is not considered to have introduced a sampling bias
on assessment of the current geological interpretation.
Geological mapping by various companies has reinforced that the strata dips
variously between 5 and 65 degrees.
Sample security
The measures taken to ensure sample security.
Sample security procedures are considered 'industry standard' for the current
period.
Samples obtained during drilling completed between 4/10/22 to the 10/10/22
were transported by exploration employees or an independent courier directly
from Broken Hill to ALS Laboratory, Adelaide.
The Company considers that risks associated with sample security are limited
given the nature of the targeted mineralisation.
Audits or reviews
The results of any audits or reviews of sampling techniques and data.
No external audits or reviews have yet been undertaken.
SECTION 2: REPORTING OF EXPLORATION RESULTS
Criteria JORC Code explanation Commentary
Mineral tenement and land tenure status Type, reference name/number, location and ownership including agreements or EL 8434 is located about 28km east of Broken Hill whilst EL 8435 is 16km east
material issues with third parties such as joint ventures, partnerships, of Broken Hill. Both tenures are approximately 900km northwest of Sydney in
overriding royalties, native title interests, historical sites, wilderness or far western New South Wales (Figures D2-1 and D2-2 in Appendix A &B,
national park and environmental settings. above).
The security of the tenure held at the time of reporting along with any known EL 8434 and EL 8435 were both granted on the 2(nd of) June 2016 to Squadron
impediments to obtaining a licence to operate in the area. Resources for a term of five (5) years for Group One Minerals. On the 25(th
of) May 2020, Squadron Resources changed its name to Wyloo Metals Pty Ltd
(Wyloo). In December 2020 the tenure was transferred from Wyloo Metals to
Broken Hill Alliance Pty Ltd a 100% subsidiary company of Castillo Copper
Limited. Both tenures were renewed on the 12(th of) August 2021 for a
further six (6) years and are due to expire on the 2(nd of) June 2027.
EL 8434 lies across two (2) 1:100,000 geology map sheets Redan 7233 and
Taltingan 7234, and two (2) 1:250,000 geology map sheets, SI54-3 Menindee, and
SH54-15 Broken Hill in the county of Yancowinna. EL 8434 consists of one
hundred and eighty-six (186) units) in the Adelaide and Broken Hill
1:1,000,000 Blocks covering an area of approximately 580km(2).
EL 8435 is located on the 1:100,000 geology map sheet Taltingan 7234, and the
1:250,000 geology map sheet SH/54-15 Broken Hill in the county of
Yancowinna. EL 8435 consists of twenty-two (22) units (Table 1) in the
Broken Hill 1:1,000,000 Blocks covering an area of approximately 68km(2).
Access to the tenures from Broken Hill is via the sealed Barrier Highway.
This road runs north-east to south-west through the northern portion of the EL
8434, passes the southern tip of EL 8435 eastern section and through the
middle of the western section of EL 8435. Access is also available via the
Menindee Road which runs north-west to south-east through the southern section
of the EL 8434. The Orange to Broken Hill Rail line also dissects EL 8435
western section the middle and then travels north-west to south-east slicing
through the eastern arm of EL 8434 (Figure D2-1).
Figure D2-1: EL 8434 and EL 8435 General Location Map
Exploration done by other parties Acknowledgment and appraisal of exploration by other parties. Explorers who were actively involved over longer historical periods in various
parts of EL8434 were: - North Broken Hill Ltd, CRAE Exploration, Major Mining
Ltd and Broken Hill Metals NL, Pasminco Exploration Ltd, Normandy Exploration
Ltd, PlatSearch NL/Inco Ltd/ EGC Pty Ltd JV and the Western Plains Gold
Ltd/PlatSearch/EGC Pty Ltd JV.
A comprehensive summary of work by previous explorers was presented in Leyh
(2009). However, more recently, follow-up field reconnaissance of areas of
geological interest, including most of the prospective zones was carried out
by EGC Pty Ltd over the various licenses. This work, in conjunction with a
detailed interpretation of aeromagnetic, gravity plus RAB / RC drill hole
logging originally led to the identification of at least sixteen higher
priority prospect areas. All these prospects were summarized in considerable
detail in Leyh (2008). Future work programs were then also proposed for each
area. Since then, further compilation work plus detailed geological
reconnaissance mapping and sampling of gossans and lode rocks has been carried
out.
A total of 22 prospects were then recognised on the exploration licence with
at least 12 occurring in and around the tenure.
With less than 45% outcropping Proterozoic terrain within the licence, this
makes it very difficult to explore and is in the main very effectively
screened from the easy application of more conventional exploration
methodologies due to a predominance of extensive Cainozoic cover sequences.
These include recent to young Quaternary soils, sands, clays and older more
resistant, only partially dissected, Tertiary duricrust regolith covered
areas. Depth of cover ranges from a few metres in the north to over 60
metres in some areas on the southern and central license.
Exploration by EGC Pty Ltd carried out in the field in the first instance has
therefore been heavily reliant upon time consuming systematic geological
reconnaissance mapping and relatable geochemical sampling. These involve a
slow systematic search over low outcropping areas, poorly exposed subcrops and
float areas as well as the progressive development of effective regolith
mapping and sampling tools. This work has been combined with a vast amount
of intermittently acquired past exploration data. The recent data
compilation includes an insufficiently detailed NSWGS regional mapping scale
given the problems involved, plus some regionally extensive, highly variable,
low-level stream and soil BLEG geochemical data sets over much of the area.
There are also a few useful local detailed mapping grids at the higher
priority prospects, and many more numerous widespread regional augers, RAB,
and percussion grid drilling data sets. Geophysical data sets including ground
magnetics, IP and EM over some prospect areas have also been integrated into
the exploration models. These are located mainly in former areas of moderate
interest and most of the electrical survey methods to date in this type of
terrain continue to be of limited application due to the high degree of
weathering and the often prevailing and complex regolith cover constraints.
Between 2007 and 2014 Eaglehawk Geological Consulting has carried out detailed
research, plus compilation and interpretation of a very large volume of
historic exploration data sourced from numerous previous explorers and dating
back to the early 1970's. Most of this data is in non-digital scanned form.
Many hard copy exploration reports (see references) plus several hundred plans
have been acquired from various sources, hard copy printed as well as
downloaded as scans from the Geological Survey of NSW DIGS system. They also
conducted field mapping, costean mapping and sampling, and rock chip sampling
and analysis.
Work Carried out by Squadron Resources and Whyloo Metals 2016-2020
Research during Year 1 by Squadron Resources revealed that the PGE-rich,
sulphide-bearing ultramafic rocks in the Broken Hill region have a
demonstrably alkaline affinity. This indicates a poor prospectivity for
economic accumulations of sulphide on an empirical basis (e.g., in comparison
to all known economic magmatic nickel sulphide deposits, which have a
dominantly tholeiitic affinity). Squadron instead directed efforts toward
detecting new Broken Hill-Type (BHT) deposits that are synchronous with basin
formation. Supporting this modified exploration rationale are the EL's
stratigraphic position, proximity to the Broken Hill line of lode, abundant
mapped alteration (e.g., gahnite and/or garnet bearing exhalative units) and
known occurrences such as the "Sisters" and "Iron Blow" prospects.
The area overlies a potential magmatic Ni-Cu-PGE source region of
metasomatised sub-continental lithospheric mantle (SCLM) identified from a
regional targeting geophysical data base. The exploration model at the time
proposed involved remobilization of Ni-Cu-PGE in SCLM and incorporation into
low degree mafic-ultramafic partial melts during a post-Paleoproterozoic plume
event and emplacement higher in the crust as chonoliths/small intrusives -
Voisey's Bay type model. Programs were devised to use geophysics and
geological mapping to locate secondary structures likely to control and
localise emplacement of Ni-Cu-PGE bearing chonoliths. Since EL8434 was
granted, the following has been completed:
• Airborne EM survey.
• Soil and chip sampling.
• Data compilation.
• Geological and logistical reconnaissance.
• Community consultations; and
• Execution of land access agreements.
Airborne EM Survey
Geotech Airborne Limited was engaged to conduct an airborne EM survey using
their proprietary VTEM system in 2017. A total of 648.92-line kilometres
were flown on a nominal 200m line spacing over a portion of the project area.
Several areas were infilled to 100m line spacing.
The VTEM data was interpreted by Southern Geoscience Consultants Pty Ltd, who
identified a series of anomalies, which were classified as high or low
priority based on anomaly strength (i.e., does the anomaly persist into the
latest channels). Additionally, a cluster of VTEM anomalies at the "Sisters"
prospect have been classified separate due to strong IP effects observed in
the data. Geotech Airborne have provided an IP corrected data and
interpretation of the data has since been undertaken.
Soil and Chip sampling
The VTEM anomalies were followed up by a reconnaissance soil sampling
programme. Spatially clustered VTEM anomalies were grouped, and follow-up soil
lines were designed. Two (2) VTEM anomalies were found to be related to
culture and consequently no soils were collected. Two (2) other anomalies
were sampled which were located above thick alluvium of Stephens Creek and
were therefore not sampled. A line of soil samples was collected over a
relatively undisturbed section at Iron Blow workings and the Sisters Prospect.
One hundred and sixty-six (166) soil samples were collected at a nominal 20cm
depth using a 2mm aluminum sieve. Two (2) rock chips were also collected
during this program. The samples were collected at either 20m or 40m spacing
over selected VTEM anomalies. The samples were pulverised and analysed by
portal XRF at ALS laboratories in Perth.
Each site was annotated with a "Regolith Regime" such that samples from a
depositional environment could be distinguished from those on exposed
Proterozoic bedrock, which were classified as an erosional environment. The
Regolith Regime groups were used for statistical analysis and levelling of the
results. The levelled data reveals strong relative anomalies in zinc at VTEM
anomaly clusters 10, 12 and 14 plus strong anomalous copper at VTEM 17.
Geology Deposit type, geological setting, and style of mineralisation. As the strata is tightly folded, the intersected cobalt-rich layers are
overstated in terms of apparent thickness, however the modelling software
calculates a true, vertical thickness. Cobalt mineralisation is commonly
associated with shears, faults, amphibolites, and a quartz-magnetite rock
within the shears, or on or adjacent to the boundaries of the Himalaya
Formation. In general, most of the cobalt and rare earth element - rich layers
have a north-northwest to north strike.
REE enrichment generally occurs as a 5 to 10-metre-thick zone between the
completely weathered layer and strongly weathered layer and it is targeted for
commercial mining (Figure D2-2). Compared to other REE deposits,
regolith-hosted rare earth element deposits are substantially low-moderate
grade (containing 0.05-0.3 wt.% extractable REEs). Nevertheless, due to its
easy extraction method, low processing costs and large abundance, the
orebodies are generally economic to be extracted (Duuring, (2020); Kanazawa
and Kamitani (2006); and Murakami, H.; Ishihara (2008)).
Figure D2-2: Weathering Profile over REE - Rich Granite
https://en.wikipedia.org/wiki/Regolith-hosted_rare_earth_element_deposits
(https://en.wikipedia.org/wiki/Regolith-hosted_rare_earth_element_deposits)
Weathering profile of regolith hosted REE deposits shown above, the legend is:
(A) Humic layer. (B) Completely weathered layer. (C) Strongly weathered layer.
(D) Weathering front. (E) Unweathered rock.
Most of the REE found in cerium monazite (Ce (PO(4))) which always contains
major to minor amounts of other REE (Nd, La, Pr, Sm etc) replacing Ce. Also,
the mineral often contains trace amounts of U and Th (coupled with Ca). This
will be collaborated with XRD and or SEM analysis.
Drill hole Information A summary of all information material to the understanding of the exploration Header information about all drillholes completed at Reefs Tank, Tors Tank and
results including a tabulation of the following information for all Material Fence Gossan have been tabulated in this release in Appendix C.
drill holes:
o easting and northing of the drill hole collar
o elevation or RL (Reduced Level - elevation above sea level in metres) of
the drill hole collar
o dip and azimuth of the hole
o down hole length and interception depth
o hole length.
If the exclusion of this information is justified on the basis that the
information is not Material and this exclusion does not detract from the
understanding of the report, the Competent Person should clearly explain why
this is the case.
Data aggregation methods In reporting Exploration Results, weighting averaging techniques, maximum No metal equivalents have been reported. Rare earth element results have
and/or minimum grade truncations (e.g., cutting of high grades) and cut-off been converted to rare earth oxides as per standard industry practice
grades are usually Material and should be stated. (Castillo Copper 2022f).
Where aggregate intercepts incorporate short lengths of high-grade results and No compositing of assay results has taken place, but rather menu options
longer lengths of low-grade results, the procedure used for such aggregation within the Datamine GDB module have been used to create fixed length 1m assay
should be stated and some typical examples of such aggregations should be intervals from the original sampling lengths.
shown in detail.
The rules follow very similarly to those used by the Leapfrog Geo software in
The assumptions used for any reporting of metal equivalent values should be creating fixed length samples.
clearly stated.
Relationship between mineralisation widths and intercept lengths These relationships are particularly important in the reporting of Exploration A database of all the historical borehole sampling has been compiled and
Results. validated. It is uncertain if there is a strong relationship between the
surface sample anomalies to any subsurface anomalous intersections due to the
If the geometry of the mineralisation with respect to the drill hole angle is possible masking by variable Quaternary and Tertiary overburden that varies in
known, its nature should be reported. depth from 0-15m. The mineralisation appears to be secondary enrichment in
the regolith clays and extremely weathered material derived from
If it is not known and only the down hole lengths are reported, there should quartzo-feldspathic pegmatites.
be a clear statement to this effect (e.g., 'down hole length, true width not
known').
Diagrams Appropriate maps and sections (with scales) and tabulations of intercepts Current surface anomalies are shown on maps released on the ASX (Castillo
should be included for any significant discovery being reported These should Copper 2022d, 2022e, 2022f and 2022g). All historical surface sampling has
include, but not be limited to a plan view of drill hole collar locations and had their coordinates converted to MGA94, Zone 54.
appropriate sectional views.
Balanced reporting Where comprehensive reporting of all Exploration Results is not practicable, All recent laboratory analytical results have been recently reported (see
representative reporting of both low and high grades and/or widths should be Castillo Copper 2022a, b, c, d, e, f, and g) for assay results.
practiced to avoid misleading reporting of Exploration Results.
Regarding the surface and sampling, no results other than duplicates, blanks
or reference standard assays have been omitted.
Other substantive exploration data Other exploration data, if meaningful and material, should be reported Historical explorers have also conducted airborne and ground gravity,
including (but not limited to): geological observations; geophysical survey magnetic, EM, and IP resistivity surveys over parts of the tenure area but
results; geochemical survey results; bulk samples - size and method of this is yet to be fully georeferenced (especially the ground IP surveys).
treatment; metallurgical test results; bulk density, groundwater, geotechnical Squadron Resources conducted an airborne EM survey in 2017 that covers Iron
and rock characteristics; potential deleterious or contaminating substances. Blow and The Sisters, but not the southern cobalt and REE prospects.
REFERENCES
Biggs, M. S., 2021a, Broken Hill Alliance, NSW Tenure Package Background
Geological Information, unpublished report to BH Alliance Pty Ltd, Sep 21,
30pp.
Biggs, M. S., 2021b, EL 8434 and EL 8435, Brief Review of Surface Sample
Anomalies Lithium, Rare Earth Elements and Cobalt, unpublished report to BH
Alliance Pty Ltd, Nov 21, 18pp.
Biggs, M.S., 2022a, BHA Cobalt Modelling and Mineral Resource Estimate Update,
unpublished memo for Castillo Copper by ROM Resources.
Biggs, M.S., 2022b, Broken Hill BHA Tenures Update, Castillo Copper,
unpublished memo prepared by ROM Resources, Mar 22, 5pp
Biggs M.S., 2022c, Geological Briefing Paper, Iron Blow Prospect, East Zone,
BHA Project (BHAE), Broken Hill, NSW, ROM Resources, prepared for Castillo
Copper Limited, August 2022
Burkett R.D., 1975, Progress Report on Exploration Licenses 780, 781, 782 and
783, Broken Hill Area, NSW for the six months to 23rd November 1975, North
Broken Hill Limited for the NSW Geological Survey, (GS1975-328)
Castillo Copper Limited, 2020, ASX Release Acquisition enhances BHT
(zinc-silver-lead) and IOCG (gold-copper) prospectivity at Broken Hill, 1st
October 2020.
Castillo Copper Limited, 2022a, ASX Release Battery metal drill-hole assays
unlock BHA East Zone potential / lithium update, 5th January 2022.
Castillo Copper Limited, 2022b, ASX Release Strategic focus to develop
significant cobalt mineralisation potential at BHA Project, 9th February 2022.
Castillo Copper Limited, 2022c, ASX Release High grade platinum confirmed at
BHA Project, 9th March 2022.
Castillo Copper Limited, 2022d ASX Release Diamond core tests demonstrate
high-grade cobalt-zinc potential at Broken Hill, 21 March 2022
Castillo Copper Limited, 2022e ASX Release, Drilling hits targeted cobalt
zones & wide pegmatite intercepts at Broken Hill 12 October 2022
Castillo Copper Limited, 2022f ASX Release, Drilling hits more wide pegmatite
intercepts at Broken Hill, 24 October 2022
Castillo Copper Limited, 2022g ASX Release, Completed auger sampling campaign
targets 6.5km(2) REE mineralisation zone, 23 December 2022
Duuring, P 2020, Rare-element pegmatites: a mineral systems analysis:
Geological Survey of Western Australia, Record 2020/7, 6p.
Kanazawa, Y.; Kamitani, M., 2006, "Rare earth minerals and resources in the
world". Journal of Alloys and Compounds. 408: 1339-1343.
doi:10.1016/j.jallcom.2005.04.033
Lees, T.C., 1978, Progress Report on Farmcote Exploration Licenses 780 and
782, Farmcote Area, Broken Hill, NSW for the six months to 23RD November 1978,
North Broken Hill Limited for the NSW Geological Survey, (GS1978-043)
Leyh, W.R., 1976, Progress Report on Exploration Licence, No. 846 Iron Blow
-Yellowstone Area, Broken Hill, New South Wales for the six months period
ended 29th June 1976, North Broken Hill Limited, Report GS1976-198, Jul 76,
88pp
Leyh, W.R., 1977a, Progress Report on Exploration Licence, No. 846 Iron Blow
-Yellowstone Area, Broken Hill, New South Wales for the six months period
ended 29th December 1976, North Broken Hill Limited, Report GS1976-198, Feb
1977, 24pp
Leyh W.R., 1977b, Progress Report on Farmcote Exploration Licenses 780 and
782, Farmcote Area, Broken Hill, NSW for the three months to 5th March 1977,
North Broken Hill Limited for the NSW Geological Survey, (GS1977-078)
Leyh W.R., 1977c, Progress Report on Farmcote Exploration Licenses 780 and
782, Farmcote Area, Broken Hill, NSW for the three months to 23rd May 1977,
North Broken Hill Limited for the NSW Geological Survey, (GS1977-078)
Leyh W.R., 1978, Progress Report on Farmcote Exploration Licenses 780 and 782,
Farmcote Area, Broken Hill, NSW for the three months to 27 October 1978, North
Broken Hill Limited for the NSW Geological Survey, (GS1977-078)
Leyh W.R., 1978 Progress Report on Exploration Licenses 1099 and 1100 for the
six months to 27 October 1978, North Broken Hill Limited for the NSW
Geological Survey, (GS1978-407)
Leyh, W.R., 1990, Exploration Report for the Third Six Monthly Period ended
12th June 1990 for EL 3238 (K Tank), Broken Hill District, New South Wales for
the six months period, Pasminco Limited, Report GS1989-226, Jun 90, 22pp
Leyh, W.R., and Lees T.C., 1977, Progress Report on Exploration Licence, No.
846 Iron Blow -Yellowstone Area, Broken Hill, New South Wales for the six
months period ended 29th June 1977, North Broken Hill Limited, Report
GS1976-198, Jul 77, 35pp
Leyh, W.R., and Larson P.D., 1981, Final Report for the Third Six Monthly
Period ended 12th June 1990 for EL 3238 (K Tank), Broken Hill District, New
South Wales for the six months period, Pasminco Limited, Report GS1989-226,
Jun 90, 22pp
McConachie, G.W., 1997, EL 4792 Redan, Annual Report for the period ending
19/2/1997, Normandy Exploration Limited, unpublished report to the GSNSW, RIN
00002672
Main, J.V., and Tucker D.F., 1981, Exploration Report for Six Month Period 8th
November 1980 to 7th May 1981, EL 1106 Rockwell, Broken Hill, NSW, CRA
Exploration Pty Ltd, GS1980-080, Jul 1981, 40pp
Mohoney, M., 2018, BHA Broken Hill Project Position Paper, Squadron Resources
Pty Ltd., Unpublished report, Mar2018, 8pp
Mortimer R., 2017, Re-interpretation of VTEM Profiles Broken Hill Area,
unpublished report by Southern Geoscience Consultants for Squadron Resources
Pty Ltd, Oct 17.
https://en.wikipedia.org/wiki/Regolith-hosted_rare_earth_element_deposits
Murakami, H.; Ishihara, S., 2008, REE mineralization of weathered crust and
clay sediment on granitic rocks in the Sanyo Belt, SW Japan and the Southern
Jiangxi Province, China". Resource Geology. 58 (4): 373-401.
doi:10.1111/j.1751-3928.2008.00071.x.
Segnit, E.R. (1946) Barium-feldspars from Broken Hill, New South Wales.
Mineralogical Magazine, 27, 166-174.
Squadron Resources Pty Ltd, 2018, Broken Hill Project Status, August 2018,
unpublished confidential presentation by Squadron Resources,
Timms, P.D., and Groves A.J., 2003, Exploration Licence 4846, The Sisters,
Annual Report to 29th May 2003, Endeavour Minerals Pty Ltd., RIN
Willis, I.L., Brown, R.E., Stroud, W.J., Stevens, B.P.J., 1983, The Early
Proterozoic Willyama Supergroup: stratigraphic subdivision and interpretation
of high to low-grade metamorphic rocks in the Broken Hill Block, New South
Wales., Geological Society of Australia Journal, 30(2), p195-2
Further work The nature and scale of planned further work (e.g., tests for lateral It is recommended that:
extensions or depth extensions or large-scale step-out drilling).
· The remaining non-sampled zones within the Core Library
Diagrams clearly highlighting the areas of possible extensions, including the drillholes, BH1, BH2, and DD90-IB3 in the north of the tenure group be
main geological interpretations and future drilling areas, provided this relogged and sampled. DD90-IB3 had 21-87m retested recently and is a good
information is not commercially sensitive. candidate for hyperspectral logging.
· A program of field mapping and ground magnetic, IP or radiometric
surveys be planned and executed at Fence Gossan. Mapping of pegmatite
outcrops is a high priority.
· Complete rehabilitation of the 2022 BHAE drilling campaign that
comprised mostly RC drilling. An application supporting an ESF2 lodgment is
yet to be approved by the NSW Resource Regulator
· Depending upon the results of the proposed geophysical surveys
above, the next drilling program will specifically target the air coring
technique over the known cobalt and REE mineralisation downdip to at least 30m
depth at all three prospects. That proposed drilling program is also
designed to increase the resource confidence of the REE to an Exploration
target or Inferred Resources to the standard of the 2012 JORC Code.
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