TIDMCCZ
RNS Number : 3650G
Castillo Copper Limited
26 July 2021
26 July 2021
CASTILLO COPPER LIMITED
("Castillo" or the "Company")
Up to 9% copper in Big One Deposit assays plus more visible
mineralisation up to 26m thick
Castillo Copper Limited (LSE and ASX: CCZ), a base metal
explorer primarily focused on copper across Australia and Zambia,
is pleased to report the initial assays for drill-holes
BO_315-317RC returned up to 9.19% Cu and verified extensions to
known mineralisation at the Big One Deposit in Mt Isa's
copper-belt. In addition, visual inspection of samples from
drill-holes BO_322-27RC identified further copper mineralisation,
with the best intercept of 26m found in BO_326RC.
Highlights
-- Initial assays for drill-holes BO_315-317RC verify up to
9.19% Cu and clearly extends known mineralisation - the best
intercepts are summarised below:
o 9m @ 1.42% Cu from 88m including 4m @ 3.06% Cu from 92m &
1m @ 9.19% Cu from 92m (BO_317RC)
o 5m @ 1.06% Cu from 141m (BO_316RC)
o 3m @ 1.22% Cu from 65m (BO_315RC)
-- Encouragingly, visual inspection shows new drill-holes have
potentially intersected copper mineralisation up to 26m - the best
intercepts are shown in Figure 1:
FIGURE 1: BEST INTERCEPTED MINERALISATION
Borehole From (m) To (m) Apparent Thickness
(m)
========= ======= ===================
BO_322RC 57 73.5 16.5
========= ======= ===================
BO_323RC 82 97 15.0
========= ======= ===================
BO_324RC 41 53 12.0
========= ======= ===================
BO_326RC 134 160 26.0
========= ======= ===================
BO_327RC 60 68 8.0
========= ======= ===================
BO_327RC 81 90 8.0
========= ======= ===================
BO_327RC 90 99 9.0
========= ======= ===================
-- Assays for samples from priority drill-holes BO_318RC1 &
BO_326RC, which exhibited visual copper intercepts up to 34m &
26m respectively, should be back shortly as the laboratory is
fast-tracking the analysis
-- Holistically, a closer examination of the initial assay
results by Castillo's geology team, highlights the following
interpretations:
o Factoring the new data points into the preliminary geological
model for the Big One Deposit suggests the underlying system is
larger than initially envisaged;
o There is now increasing evidence that copper mineralisation is
potentially structural as it extends beyond the trachyte/dacite
dyke; and
o Using geophysics has enabled significantly better targeting
and, in turn, optimised the results of the drilling campaign so
far
Simon Paull, Managing Director of Castillo Copper, said: "It is
encouraging there is a strong correlation between visual
mineralisation and the assays, as the Board optimistically looks
forward to receiving further results. Otherwise, the progress of
the drilling campaign is taking shape, especially verification the
underlying copper system at the Big One Deposit is likely to be
larger than our geology team's initial expectations."
ASSAY RESULTS - MORE VISIBLE COPPER MINERALISATION
Encouraging initial assays
The initial assay results for drill-holes BO_315-317RC (Figure
2) are encouraging as up to 9.19% Cu was intersected, while the
intercepts clearly extend known mineralisation.
A summary of the best intercepts is shown below:
-- 9m @ 1.42% Cu from 88m including 4m @ 3.06% Cu from 92m & 1m @ 9.19% Cu from 92m (BO_317RC)
-- 5m @ 1.06% Cu from 141m (BO_316RC)
-- 3m @ 1.22% Cu from 65m (BO_315RC)
FIGURE 2: BIG ONE DEPOSIT - POSITION OF DRILL-HOLES 315RC-17RC
(Available to view on ASX announcement)
There are several interpreted takeaways the geology team has
determined post-analysis of the initial results, including:
-- Incorporating the fresh data points into the preliminary
geological model for the Big One Deposit suggests the underlying
system is larger than initial expectations,
-- There is now demonstrable evidence that Copper mineralisation
is structural as there is increasing evidence that it potentially
extends beyond the trachyte/dacite dyke (refer Figure 3 - cross
section for BO_315RC-316RC); and
-- The use of geophysics has enabled significantly better
targeting and, in turn, delivered drilling and assay results higher
than initially anticipated.
FIGURE 3: CROSS SECTION - DRILL-HOLES 315RC-316RC (Available to
view on ASX announcement)
Drilling down, the assay results verify there is a relatively
strong correlation to the visual estimates of sulphides and
alteration minerals. Notably, there were incremental zones outside
these depths with 1-6m low tenor copper mineralisation ranging from
500-2,500ppm Cu coupled to elevated silver-cobalt levels.
However, consistent with the 2020 drilling campaign, there was
no anomalous lead-zinc found at the Big One Deposit, while weak
gold mineralisation (0.05-0.15 ppm) was apparent, it did not
correlate with the copper zones, rather dolomitic siltstones and
quartzites.
Visual copper mineralisation
Consistent with drill-holes BO_315RC-321RC, visual inspection
shows that all new drill-holes have potentially intersected copper
mineralisation. There are several significant intercepts ranging
from 8m up to 26m (Figure 4 and Appendix A).
Assays for the priority drill-holes, BO_318RC and BO_326RC, with
visual copper intercepts at 34m and 26m respectively, is being
expedited. As such, the results of the analysis should be returned
within the next few weeks.
FIGURE 4: BIG ONE DEPOSIT - QUALITATIVE ASSESSMENT OF DRILLHOLES
322RC-327RC
Borehole From (m) To (m) Apparent Thickness Comments
(m)
BO_322RC 57 73.5 16.5 Dacitic
--------- ------- ------------------- ------------------------------
BO_323RC 8 9 1.0 Dacitic, pervasive orthoclase
--------- ------- ------------------- ------------------------------
BO_323RC 82 97 15.0 Dacitic, some orthoclase
--------- ------- ------------------- ------------------------------
BO_324RC 3 6 3.0 Quartzite
--------- ------- ------------------- ------------------------------
BO_324RC 33 40 7.0 Fractured quartzite
--------- ------- ------------------- ------------------------------
BO_324RC 41 53 12.0 Dacite
--------- ------- ------------------- ------------------------------
BO_325RC 2 4 2.0 Dacite
--------- ------- ------------------- ------------------------------
BO_325RC 45 46 1.0 Dacitic
--------- ------- ------------------- ------------------------------
BO_326RC 5 9 4.0 Dacite
--------- ------- ------------------- ------------------------------
Quartzite with abundant
BO_326RC 27 28 1.0 pyrite
--------- ------- ------------------- ------------------------------
BO_326RC 96 100 4.0 Dacite
--------- ------- ------------------- ------------------------------
BO_326RC 134 160 26.0 Dacite
--------- ------- ------------------- ------------------------------
BO_327RC 60 68 8.0 Dacite
--------- ------- ------------------- ------------------------------
BO_327RC 81 90 8.0 Dacite
--------- ------- ------------------- ------------------------------
BO_327RC 90 99 9.0 Quartzite
--------- ------- ------------------- ------------------------------
Notes:
1. Samples have been taken at 1m intervals
2. Mineralisation estimated from field geologists rock chip estimates
3. Each dyke intersections also characterised by potassic and chloritic alternation
4. True vertical depths will be calculated by Minescape block model procedures
5. A zone of limited mineralisation inferred to be associated
with the dyke was intersected in each drill-hole
Source: CCZ geology team
Next steps
There are several ongoing steps, including:
-- Reporting of the assay results for BO_318-27RC which are due back from the laboratory; and
-- Finalise logistics, access, cultural heritage, and targets
for the drilling campaign at the Arya Prospect.
In addition to this release, a PDF version of this report with
supplementary information and images can be found on the Company's
website:
https://castillocopper.com/investors/announcements/
For further information, please contact:
Castillo Copper Limited +61 8 6558 0886
Simon Paull (Australia), Managing Director
Gerrard Hall (UK), Director
SI Capital Limited (Financial Adviser and
Corporate Broker) +44 (0)1483 413500
Nick Emerson
Luther Pendragon (Financial PR) +44 (0)20 7618 9100
Harry Chathli, Alexis Gore, Joe Quinlan
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 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.
-- 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 Statement
The information in this report that relates to Exploration
Results for "Big One Deposit" is based on information compiled or
reviewed by Mr Mark Biggs. Mr Biggs is both a shareholder and
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.
APPIX A: DRILL-HOLE DATA & LOCATIONS
Location
The location of the drill-holes completed is provided in Figure
A1 below, with a companion sketch map relative to those previously
drilled in the 2020 campaign (Figure A2).
FIGURE A1: LOCATION OF DRILL-HOLES
Site ID Easting Northing Total Grid Azimuth Dip Estimated Type
(GDA94) (GDA94) Depth days
(m)
BO_315RC 335413 7880315 80 320 -58 2.0 Redrill 201RC
========= ========= ======= ============= ==== ========== ===================
BO_316RC 335423 7880298 155 349 -68 1.2 Redrill 202RC
========= ========= ======= ============= ==== ========== ===================
BO_317RC 335394 7880291 125 339 -61 1.5 Redrill 306RC
========= ========= ======= ============= ==== ========== ===================
BO_318RC 335432 7880284 203 333 -73 1.2 Redrill 203RC
========= ========= ======= ============= ==== ========== ===================
BO_319RC 335285 7880268 149 3456 -69 1.5 Redrill 312RC
========= ========= ======= ============= ==== ========== ===================
Abandoned due
to high water
BO_320RC 335312 7880204 83 337.6 -60 1.3 flow
========= ========= ======= ============= ==== ========== ===================
BO_321RC 335232 7880238 137 325 -60 1.3 -
========= ========= ======= ============= ==== ========== ===================
BO_322RC 335185 7880220 131 325 -60 1.2 -
========= ========= ======= ============= ==== ========== ===================
BO_323RC 335160 7880189 131 337.5 -60 1.3 Matched to 325RC
========= ========= ======= ============= ==== ========== ===================
Abandoned due
to faulted ground
BO_324RC 335118 7880197 76 335 -60 1.2 and cavities
========= ========= ======= ============= ==== ========== ===================
BO_325RC 335116 7880296 130 157.4 -60 1.3 Oriented south
========= ========= ======= ============= ==== ========== ===================
Abandoned due
to high water
BO_326RC 335482 7880296 191 325 -60 3 flow
========= ========= ======= ============= ==== ========== ===================
BO_327RC 335333 7880266 173 325 -60 1.5 -
========= ========= ======= ============= ==== ========== ===================
Note:
1. Some locations corrected after loading to database and
plotting extents - compared to previous ASX releases.
Source: CCZ geology team
FIGURE A2: LOCATION OF NEW DRILLING (Available to view on ASX
announcement)
Observations
BO_322RC to 327RC are all new drill-holes either along the dyke
or testing the IP anomalies. Of note is that each of the new
drillholes have intersected the trachyte - porphyritic dacite dyke
and associated mineralisation within and surrounding the dyke.
The mineralisation is characterised by potassic alteration and a
suite of minerals such as orthoclase, epidote, sericite, and
variable iron oxide contents. Note, orthoclase up to 50% of a 1m
interval has been recognised.
Mineralisation within the five drill-holes completed are listed
in Figure A3, again highlighting the mineralised zone extends
outside the wireframe of the igneous dyke. The apparent thickness
of the major mineralised zone varied between 1m up to 26m.
FIGURE A3: QUALITATIVE ASSESSMENT OF DRILLHOLES 322RC TO
327RC
Borehole From To Apparent Orthoclase Epidote Sericite Chalcocite Comments
(m) (m) Thick. (%) (%) (%) (%)
(m)
BO_322RC 57 73.5 16.5 1-10 0 1-2 0-5 Dacitic
===== ===== ========= =========== ======== ========= =========== =========================
Dacitic, pervasive
BO_323RC 8 9 1.0 1-20 1-2 0 3-5 orthoclase
===== ===== ========= =========== ======== ========= =========== =========================
BO_323RC 82 97 15.0 1-10 1-5 0 0-3 Dacitic, some orthoclase
===== ===== ========= =========== ======== ========= =========== =========================
BO_324RC 3 6 3.0 1-5 0 1-3 1-5 Quartzite
===== ===== ========= =========== ======== ========= =========== =========================
BO_324RC 33 40 7.0 1-10 0 0 1-2 Fractured quartzite
===== ===== ========= =========== ======== ========= =========== =========================
Dacite; hole abandoned
BO_324RC 41 53 12.0 2-15 1-5 1-5 1-6 at 76m
===== ===== ========= =========== ======== ========= =========== =========================
BO_325RC 2 4 2.0 5-10 0 0 1-5 Dacite
===== ===== ========= =========== ======== ========= =========== =========================
BO_325RC 45 46 1.0 1-5 1-5 1-5 1-3 Dacitic
===== ===== ========= =========== ======== ========= =========== =========================
BO_326RC 5 9 4.0 5-10 0 0 1-3 Dacite
===== ===== ========= =========== ======== ========= =========== =========================
Quartzite with
BO_326RC 27 28 1.0 0-5 0 1-5 0-1 abundant pyrite
===== ===== ========= =========== ======== ========= =========== =========================
BO_326RC 96 100 4.0 0-5 0-2 1-5 1-3 Dacite
===== ===== ========= =========== ======== ========= =========== =========================
BO_326RC 134 160 26.0 0-25 1-5 0-10 1-6 Dacite
===== ===== ========= =========== ======== ========= =========== =========================
BO_327RC 60 68 8.0 0-10 1-3 0-2 1-5 Dacite
===== ===== ========= =========== ======== ========= =========== =========================
BO_327RC 81 90 8.0 0-15 1-5 0-3 1-5 Dacite
===== ===== ========= =========== ======== ========= =========== =========================
BO_327RC 90 99 9.0 0-20 1-3 0 5-10 Quartzite
===== ===== ========= =========== ======== ========= =========== =========================
Notes:
1. Samples have been taken at 1m intervals
2. Mineralisation estimated from field geologists rock chip estimates
3. Each dyke intersections also characterised by potassic and chloritic alteration
4. True vertical depths will be calculated by Minescape block model procedures
5. A zone of mineralisation inferred to be associated with the
dyke was intersected in each drill hole
Source: CCZ geology team
APPIX B: JORC CODE, 2012 EDITION - TABLE 1
The following JORC Code (2012 Edition) Table 1 is primarily
supplied for the provision of the 3rd release of data for the 2021
Drilling Program at the Big One Deposit.
Section 1 Sampling Techniques and Data
Criteria JORC Code explanation Commentary
Sampling
techniques * Nature and quality of sampling (eg cut channels, * For the 2021 program, samples are taken off a cyclone
random chips, or specific specialised industry for every metre drilled, put through a three tier,
standard measurement tools appropriate to the 87.5/12.5 splitter where approximately 2.5 kg of RC
minerals under investigation, such as down hole gamma chip samples were collected for every metre drilled.
sondes, or handheld XRF instruments, etc). These The remainder was bagged separately and stored in
examples should not be taken as limiting the broad case additional sub sampling is required before the
meaning of sampling. end of the program.
* Include reference to measures taken to ensure sample * Weights recovered from riffle splitting varied
representivity and the appropriate calibration of any between 1-2kg for both the 1970 and 1993 drilling
measurement tools or systems used. programs.
* Aspects of the determination of mineralisation that * For the 2021 program, samples were also composited
are Material to the Public Report. every four metres where visual inspection did not
initially indicate copper mineralisation. All samples
were collected to maximise optimal representation for
* In cases where 'industry standard' work has been done each sample.
this would be relatively simple (e.g., 'reverse
circulation drilling was used to obtain 1 m samples
from which 3 kg was pulverised to produce a 30 g * Each metre sample had an amount removed for washing
charge for fire assay'). In other cases, more and cleaning and sieving then place into metre
explanation may be required, such as where there is allocated chip trays (see Figure A1-1). These chips
coarse gold that has inherent sampling problems. were logged on site by the rig geologists and those
Unusual commodities or mineralisation types (e.g., logs have been saved into a spreadsheet and stored on
submarine nodules) may warrant disclosure of detailed the Company server. Any visible mineralisation,
information. alteration or other salient features were recorded in
the logs. Industry-wide, acceptable, standard
practices were adhered to for the drilling and
sampling of each metre as per the drilling and
sampling Procedures set out before commencement of
the drilling programme.
============================================================ =================================================================
Drilling
techniques * Drill type (e.g., core, reverse circulation, * Reverse Circulation, RC, drilling was utilised for
open-hole hammer, rotary air blast, auger, Bangka, all holes drilled to date at Big One Deposit.
sonic, etc) and details (e.g., core diameter, triple
or standard tube, depth of diamond tails,
face-sampling bit, or other type, whether core is
oriented and if so, by what method, etc).
============================================================ =================================================================
Drill sample
recovery * Method of recording and assessing core and chip * For the 2021 program, within acceptable industry
sample recoveries and results assessed. standard limits, all samples collected were of near
equal mass and recoveries were also within acceptable
limits for RC drilling and all recorded in the daily
* Measures taken to maximise sample recovery and ensure logs. Every effort was made on site to maximise
representative nature of the samples. recovery including cleaning out the sample trays,
splitter and cyclone and ensuring that the drillers
progressed at a steady constant rate for the rig to
* Whether a relationship exists between sample recovery easily complete each metre effectively.
and grade and whether sample bias may have occurred
due to preferential loss/gain of fine/coarse
material.
============================================================ =================================================================
Logging
* Whether core and chip samples have been geologically * For all drilling programs, every metre drilled and
and geotechnically logged to a level of detail to sampled was logged geologically in accordance with
support appropriate Mineral Resource estimation, industry-wide acceptable standard for RC logging and
mining studies and metallurgical studies. the logging was qualitative in nature with every
metre logged. Unfortunately, lithology dictionaries
and descriptions varied between programs. The 2021
* Whether logging is qualitative or quantitative in programs also recorded visible sulphide and carbonate
nature. Core (or costean, channel, etc) photography. concentrations and alteration minerals, such as
orthoclase, epidote, chlorite, and sericite.
* The total length and percentage of the relevant
intersections logged.
============================================================ =================================================================
Sub-sampling
techniques * If core, whether cut or sawn and whether quarter, * For the 2021 program, samples with copper
and sample half or all core taken.
preparation
* Each metre sample had an amount removed for washing
* If non-core, whether riffled, tube sampled, rotary and cleaning and sieving then place into metre
split, etc and whether sampled wet or dry. allocated chip trays. These chips were logged on site
by the rig geologists and those logs have been saved
into a spreadsheet and stored on the Company server.
* For all sample types, the nature, quality, and Any visible mineralisation, alteration or other
appropriateness of the sample preparation technique. salient features were recorded in the logs. Industry
wide, acceptable, standard practices were adhered to
for the drilling and sampling of each metre as per
* Quality control procedures adopted for all the Drilling and Sampling Procedures set out before
sub-sampling stages to maximise representivity of commencement of the drilling programme.
samples.
* Any reporting of significant mineralised intervals
* Measures taken to ensure that the sampling is was on a received mass x interval calculation (i.e.,
representative of the in-situ material collected, weight-averaged).
including for instance results for field
duplicate/second-half sampling.
* Whether sample sizes are appropriate to the grain
size of the material being sampled.
============================================================ =================================================================
Quality
of assay * The nature, quality and appropriateness of the * CCZ's first second (4) RC holes will be assayed by an
data and assaying and laboratory procedures used and whether independent laboratory, ALS in Brisbane Australia.
laboratory the technique is considered partial or total. Methods used were as follows:
tests
* For geophysical tools, spectrometers, handheld XRF o Gold - by method Au-AA25 30g charge (fire Assay
instruments, etc, the parameters used in determining with AAS finish);
the analysis including instrument make and model, o High gold values within oxide zone/supergene zone
reading times, calibrations factors applied and their may need further testing by method Au-SCR21.
derivation, etc. o Copper and 32 other - by method ME-ICP41 (HF-HN03-HCL04
acid digest, HCL leach and ICP-AES finish).
o Over-limit copper (>10,000 ppm [0.01%]) to be re
* Nature of quality control procedures adopted (eg assayed for copper by method Cu-OC62 (HF-HN03-HCL04
standards, blanks, duplicates, external laboratory acid digest, HCL leach and ICP-AES finish).
checks) and whether acceptable levels of accuracy * These analytical methods are considered as suitable
(i.e. lack of bias) and precision have been and appropriate for this type of mineralisation.
established.
* For the current drilling program ALS Brisbane will
analyse all samples. All elements except for gold
were analysed by method ME-MS61 (41 element testing
via Aqua Regia digest then ICP-AES) and with any
copper assays >1%, the copper will be redone using
method Cu-OG46 with ICP-AES. The gold was done by
method AA25. All methods used were both suitable and
appropriate for the styles of mineralisation present
in the Big One Deposit at the time of sampling.
============================================================ =================================================================
Verification
of sampling * The verification of significant intersections by * CCZ's first 3 RC hole assay results from ALS have
and assaying either independent or alternative company personnel. been reviewed by two independent consultant
geologists. Assays from the 2021 drilling program
have yet to be returned.
* The use of twinned holes.
* For current the rock chip sampling, Independent
* Documentation of primary data, data entry procedures, Laboratory assaying by ALS has confirmed, within
data verification, data storage (physical and acceptable limits, the occurrences of high-grade
electronic) protocols. copper inferred from the initial XRF readings.
Laboratory standards and duplicates were used in
accordance with standard procedures for geochemical
* Discuss any adjustment to assay data. assaying.
============================================================ =================================================================
Location
of data * Accuracy and quality of surveys used to locate drill * The first 16 RC holes done by CCZ in 2021 have had
points holes (collar and down-hole surveys), trenches, mine their location surveyed by GPS and will, at the
workings and other locations used in Mineral Resource completion of drilling, be surveyed by differential
estimation. GPS by independent licensed surveyors.
* Specification of the grid system used. * The spatial location for these holes has been
differentially surveyed into MGA94 - Zone 54. Collar
heights are to the Australian Height Datum.
* Quality and adequacy of topographic control.
* The locations of the 1970 drillholes and 1993
drillholes have been determined from georeferencing
several plans and utilizing tables in historical
reports. Location errors for the 1970 drilling is
+/-10m whereas it is about 1/2 that for the 1993
holes.
============================================================ =================================================================
Data spacing
and * Data spacing for reporting of Exploration Results. * The first 16 RC holes were part of a 35-hole program
distribution that was set out on a nominal 100m pattern or to
redrill 2020 holes that were found to be too short.
* Whether the data spacing, and distribution is The 1970 drilling was set at a 30m spacing and the
sufficient to establish the degree of geological and 1993 drilling also at a 50m spacing. At the
grade continuity appropriate for the Mineral Resource completion of all the planned holes, the drillhole
and Ore Reserve estimation procedure(s) and collars will be differentially surveyed by
classifications applied. independent, licensed surveyors and the grid pattern
verified.
* Whether sample compositing has been applied.
============================================================ =================================================================
Orientation
of data * Whether the orientation of sampling achieves unbiased * The current CCZ RC drilling programme (Figure A2-2)
in relation sampling of possible structures and the extent to has had all holes oriented to intersect the
to which this is known, considering the deposit type. mineralised structure/zone subsurface perpendicularly
geological and therefore does not constitute any perceived bias.
structure The typical dip direction of the new drillholes is
* If the relationship between the drilling orientation 335-350 deg (Grid North).
and the orientation of key mineralised structures is
considered to have introduced a sampling bias, this
should be assessed and reported if material. * Rock chip samples have also been taken at areas of
interest from observed mineralisation along the line
of lode of the mineralised dyke, secondary structures
,
and surrounding spoil heaps.
============================================================ =================================================================
Sample
security * The measures taken to ensure sample security. * Each day's RC samples were removed from site and
stored in a secure location off site.
* The RC chip samples taken were securely locked within
the vehicle on site until delivered to Mt Isa for
despatch to the laboratory in person by the field
personnel.
============================================================ =================================================================
Audits or
reviews * The results of any audits or reviews of sampling * This will be done once all 28 holes in CCZ's Stage
techniques and data. 2021 program, and their assay results have been
verified.
* For the historical drilling, the sampling techniques
and the data generated from the Laboratory Assay
results have been peer reviewed by consultant
geologists familiar with the overall Mt Oxide Project
and deemed to be acceptable. To facilitate this, six
(6) sites have twinned drillholes, with the current
drilling spudded immediately adjacent to the
historical 1970, 1993 and 2020 drilling programs.
============================================================ =================================================================
FIGURE B1: DRILLHOLE LOCATION (Available to view on ASX
announcement)
Section 2 Reporting of Exploration Results
(Criteria listed in the preceding section also apply to this
section.)
Mineral
tenement * Type, reference name/number, location and ownership * The following mineral tenures are held 100% by
and land including agreements or material issues with third subsidiaries of Castillo Copper Limited, totalling an
tenure status parties such as joint ventures, partnerships, area of 736.8 km(2) in the "Mt Oxide North Project":
overriding royalties, native title interests,
historical sites, wilderness or national park and
environmental settings. o EPM 26574 (Valparaisa North) - encompasses the Big
One historical mineral resource, Holder Total Minerals
Pty Ltd, granted 12-June-2018 for a 5-year period over
* The security of the tenure held at the time of 100 sub-blocks (323.3Km(2) ), Expires 11-June-2023.
reporting along with any known impediments to o EPM 26462 (Big Oxide North) - encompasses the 'Boomerang'
obtaining a licence to operate in the area. historical mine and the 'Big One' historical mine,
Holder: QLD Commodities Pty Ltd, granted: 29-Aug-2017
for a 5-year period over 67 sub-blocks (216.5Km(2)
), Expires: 28-Aug-2022.
o EPM 26525 (Hill of Grace) - encompasses the Ayra
(previously Myally Gap) significant airborne EM anomaly,
Holder: Total Minerals Pty Ltd for a 5-year period
over 38 sub-blocks (128.8Km(2) ), Granted: 12-June-2018,
Expires: 11-June-2023.
o EPM 26513 (Torpedo Creek/Alpha Project) - Granted
13-Aug-2018 for a 5-year period over 23 sub-blocks
(74.2Km(2) ), Expires 12-Aug-2023; and
o EPMA 27440 (The Wall) - An application lodged on
the 12-Dec-2019 over 70 sub-blocks (215Km(2) ) by
Castillo Copper Limited. The tenure was granted on
the 18(th of) March 2021.
* A check on the tenures in 'application-status' was
completed in 'GeoResGlobe' on the 2(ND) July-2021.
=============================================================== =============================================================================
Exploration
done by other * Acknowledgment and appraisal of exploration by other * Historical QDEX / mineral exploration reports have
parties parties. been reviewed for historical tenures that cover or
partially cover the Project Area in this
announcement. Federal and State Government reports
supplement the historical mineral exploration
reporting (QDEX open file exploration records).
* Most explorers were searching for Cu-Au-U, and,
proving satellite deposit style extensions to the
several small sub-economic copper deposits (e.g., Big
Oxide and Josephine).
* With the Mt Oxide North Project in regional proximity
to Mt Isa and numerous historical and active mines,
the Project area has seen portions of the historical
mineral tenure subject to various styles of surface
sampling, with selected locations typically targeted
by shallow drilling (Total hole depth is
characteristically less than 50m).
* The Mt Oxide North project tenure package has a
significant opportunity to be reviewed and explored
by modern exploration methods in a coherent package
of EPM's, with three of these forming a contiguous
tenure package.
* Various Holders and related parties of the 'Big One'
historical mining tenure (ML8451) completed a range
of mining activities and exploration activities on
what is now the 'Big One' prospect for EPM 26574. The
following unpublished work is acknowledged (and
previously shown in the reference list):
o Katz, E., 1970, Report on the Big One, Mt Devine,
and Mt Martin Mining Lease Prospects, Forsayth Mineral
Exploration NL, report to the Department of Mines,
CR5353, 63pp
o West Australian Metals NL, 1994. Drill Programme
at the "Big One" Copper Deposit, North Queensland for
West Australian Metals NL.
o Wilson, D., 2011. 'Big One' Copper Mine Lease 5481
Memorandum - dated 7 May 2011.
o Wilson, D., 2015. 'Big One' Mining Lease Memorandum
- dated 25 May 2015: and
o Csar, M, 1996. Big One & Mt Storm Copper Deposits.
Unpublished field report.
* The reader of the current ASX Release is referred to
the CCZ's first publication of the 1993 historical
reverse circulation drilling results for additional
diagrams and drilling information ("Historic drill
data verifies grades up to 28.40% Cu from
* The SRK Independent Geologists Report released by CCZ
on the ASX on 28-July-2020 contains further details
on the 'Exploration done by other parties -
Acknowledgment and appraisal of exploration by other
parties' this report is formally titled "A Competent
Persons Report on the Mineral Assets of Castillo
Copper Limited" Prepared as part of the Castillo
Copper Limited (ASX: CCZ, LSE: CCZ) LSE Prospectus,
with the effective date of the 17-July-2020.
=============================================================== =============================================================================
Geology
* Deposit type, geological setting, and style of * The Mt Oxide North project is located within the Mt
mineralisation. Isa Inlier of western Queensland, a large, exposed
section of Proterozoic (2.5 billion- to
540-million-year-old) crustal rocks. The inlier
records a long history of tectonic evolution, now
thought to be like that of the Broken Hill Block in
western New South Wales.
* The Mt Oxide North project lies within the Mt Oxide
Domain, straddling the Lawn Hill Platform and
Leichhardt River Fault Trough. The geology of the
tenement is principally comprised of rocks of the
Surprise Creek and Quilalar Formations which include
feldspathic quartzites, conglomerates, arkosic grits,
shales, siltstones and minor dolomites and
limestones.
* The Project area is cut by a major fault zone,
trending north- northeast - south- southwest across
the permits. This fault is associated with major
folding, forming several tight synclines- anticline
structures along its length.
* The Desktop studies commissioned by CCZ on the
granted mineral tenures described four main styles of
mineralisation account for most mineral resources
within the rocks of the Mt Isa Province (after
Withnall & Cranfield, 2013).
o Sediment hosted silver-lead-zinc - occurs mainly
within fine-grained sedimentary rocks of the Isa Super
basin within the Western Fold Belt. Deposits include
Black Star (Mount Isa Pb-Zn), Century, George Fisher
North, George Fisher South (Hilton) and Lady Loretta
deposits.
o Brecciated sediment hosted copper - occurs dominantly
within the Leichhardt, Calvert, and Isa Super basin
of the Western Fold Belt, hosted in brecciated dolomitic,
carbonaceous, and pyritic sediments or brecciated rocks
proximal to major fault/shear zones. Includes the Mount
Isa copper orebodies and the Esperanza/Mammoth mineralisation.
o Iron-oxide-copper-gold ("IOCG") - predominantly chalcopyrite-pyrite
magnetite/hematite mineralisation within high grade
metamorphic rocks of the Eastern Fold Belt. Deposits
of this style include Ernest Henry, Osborne, and Selwyn;
and
o Broken Hill type silver-lead-zinc - occur within
the high-grade metamorphic rocks of the Eastern Fold
Belt. Cannington is the major example, but several
smaller currently sub-economic deposits are known.
* Gold is primarily found associated with copper within
the IOCG deposits of the Eastern Fold Belt. However,
a significant exception is noted at Tick Hill where
high grade gold mineralisation was produced, between
1991 and 1995 by Carpentaria Gold Pty Ltd, some 700
000 tonnes of ore was mined at an average grade of
22.5 g/t Au, producing 15 900 kg Au. The Tick Hill
deposit style is poorly understood (Withnall &
Cranfield, 2013).
* ROM Resources had noted in a series of recent reports
for CCZ on the granted tenures, that cover the known
mineralisation styles including:
o Stratabound copper mineralisation within ferruginous
sandstones and siltstones of the Surprise Creek Formation.
o Disseminated copper associated with trachyte dykes.
o Copper-rich iron stones (possible IOCG) in E-W fault
zones; and
o possible Mississippi Valley Type ("MVT") stockwork
sulphide mineralisation carrying anomalous copper-lead-zinc
and silver.
* The Mt Oxide and Mt Gordon occurrences are thought to
be breccia and replacement zones with interconnecting
faults. The Mt Gordon/Mammoth deposit is hosted by
brittle quartzites, and Esperanza by carbonaceous
shales. Mineralisation has been related to the Isan
Orogeny (1,590 - 1,500 Ma).
* Mineralisation at all deposits is primarily
chalcopyrite-pyrite-chalcocite, typically as massive
sulphide within breccias.
* At the Big One prospect, West Australian Metals NL
described the mineralisation as (as sourced from the
document "West Australian Metals NL, 1994. Drill
Programme at the "Big One" Copper Deposit, North
Queensland for West Australian Metals NL."):
o The targeted lode / mineralised dyke is observable
on the surface. The mineralisation targeted in the
1993 drilling programmed is a supergene copper mineralisation
that includes malachite, azurite, cuprite, and tenorite,
all associated with a NE trending fault (062(o) to
242(o) ) that is intruded by a porphyry dyke.
o The mineralised porphyry dyke is vertical to near
vertical (85(o) ), with the 'true width' dimensions
reaching up to 7m at surface.
o At least 600m in strike length, with strong Malachite
staining observed along the entire strike length, with
historical open pits having targeted approximately
200m of this strike. Exact depth of mining below the
original ground surface is not clear in the historical
documents, given the pits are not battered it is anticipated
that excavations have reached 5m to 10m beneath the
original ground surface.
o Associated with the porphyry dyke are zones of fractured
and/or sheared rock, the siltstones are described as
brecciated, and sandstones around the shear as carbonaceous.
o The known mineralisation from the exploration activities
to date had identified shallow supergene mineralisation,
with a few drillholes targeting deeper mineralisation
in and around the 200m of strike historical open cut
pits.
o A strongly altered hanging wall that contained malachite
and cuprite nodules. Chalcocite mineralization has
been identified but it is unclear on the prevalence
of the Chalcocite; and
o The mineralisation was amenable to high grade open
pit mining methods of the oxide mineralization (as
indicated by numerous historical open pit shallow workings
into the shear zone).
* Desktop studies commissioned by CCZ and completed by
ROM Resources and SRK Exploration have determined
that the Big One prospect is prospective for Cu, Co,
and Ag.
* Desktop studies commissioned by CCZ have determined
the Boomerang prospect contains:
o Secondary copper staining over 800m of strike length.
o Associated with a major east-west trending fault
that juxtaposes the upper Surprise Creek Formation
sediments against both the underlying Bigie Formation
and the upper Quilalar Formation units.
* At the 'Flapjack' prospect there is the additional
potential for:
o Skarn mineralisation for Cu-Au and/or Zn-Pb-Cu from
replacement carbonate mineralisation, particularly
the Quilalar Formation.
o Thermal Gold Auroele mineralisation is a potential
model due to the high silica alteration in thermal
aureole with contact of A-Type Weberra Granite - related
to the Au mineralisation; and/or
o IOCG mineralisation related to chloride rich fluids.
* At the 'Crescent' prospect there is the additional
potential for:
o Skarn mineralisation for Cu-Au and/or Zn-Pb-Cu from
replacement carbonate mineralisation, particularly
the Quilalar Formation; and/or
o Thermal Gold Auroele mineralisation is a potential
model due to the high silica alteration in thermal
aureole with contact of A-Type Weberra Granite - related
to the Au mineralisation; and
o IOCG mineralisation related to potassic rich fluids.
* At the 'Arya' prospect there is the additional
potential for:
o Supergene mineralisation forming at the surface along
the fault, fault breccia, and the Surprise Creek Formation
'PLrd' rock unit ('Prd' historical).
o Epigenetic replacement mineralisation for Cu (with
minor components of other base metals and gold) from
replacement carbonate mineralisation, particularly
the Surprise Creek Formation.
o Skarn mineralisation for Cu-Au and/or Zn-Pb-Cu from
replacement carbonate mineralisation, particularly
the Surprised Creek Formation.
o Sulphide mineralisation within breccia zones, along
stress dilation fractures, emplaced within pore spaces,
voids, or in other rock fractures; and/or
o IOCG mineralisation related to chloride rich fluids.
* A selection of publicly available QDEX documents /
historical exploration reports have been reviewed,
refer to Section 2, sub-section "Further Work" for
both actions in progress and proposed future actions.
* The SRK Independent Geologists Report released by CCZ
on the ASX on 28-July-2020 contains further details
on the 'Geology - Deposit type, geological setting
and style of mineralisation': this report is formally
titled "A Competent Persons Report on the Mineral
Assets of Castillo Copper Limited" Prepared as part
of the Castillo Copper Limited (ASX: CCZ, LSE: CCZ)
LSE Prospectus, with the effective date of the
17-July-2020.
=============================================================== =============================================================================
Drill hole
Information * A summary of all information material to the * For the current program, all drillhole information
understanding of the exploration results including a was coded to the same formatted spreadsheets used by
tabulation of the following information for all CCZ, being hand-encoded from hard-copy reports, plans,
Material drill holes: and cross-sections.
o easting and northing of the drill * For CCZ's current drilling program, this information
hole collar has been recorded in formatted spreadsheets during
o elevation or RL (Reduced Level the drilling and will be checked and verified at the
- elevation above sea level in metres) conclusion of the current program. The current
of the drill hole collar reported holes (315-317RC) are listed in Appendix 2,
o dip and azimuth of the hole with previous drilling collars listed in the 11(TH)
o down hole length and interception of January ASX release (307-314RC).
depth
o hole length.
* If the exclusion of this information is justified on * A summary of the holes drilled are given at the end
the basis that the information is not Material and of this section.
this exclusion does not detract from the
understanding of the report, the Competent Person
should clearly explain why this is the case.
=============================================================== =============================================================================
Data
aggregation * In reporting Exploration Results, weighting averaging * Queries on some assays are currently pending on CCZ's
methods techniques, maximum and/or minimum grade truncations current drilling program.
(e.g., cutting of high grades) and cut-off grades are
usually Material and should be stated.
* For historical surface sampling, Independent
Laboratory Assay results for soil and rock chip
* Where aggregate intercepts incorporate short lengths samples from the Big One Deposit were averaged if
of high-grade results and longer lengths of low-grade more than one reading or determination was given.
results, the procedure used for such aggregation
should be stated and some typical examples of such
aggregations should be shown in detail. * Copper grades were reported in this ASX release as
per the received laboratory report, i.e., there was
no cutting of high-grade copper results as they are
* The assumptions used for any reporting of metal directly relatable to high grade mineralisation
equivalent values should be clearly stated. styles readily visible in the relevant samples and
modelling has yet not commenced.
* There were no cut-off grades factored into any assay
results reported, however once modelling commences a
high cut-off grade of 10,000ppm or 10% copper will be
used.
=============================================================== =============================================================================
Relationship
between * These relationships are particularly important in the * When available, all mineralised intervals (i.e.,
mineralisation reporting of Exploration Results. >500ppm) have been reported in this and previous ASX
widths and releases as the "as-intersected" apparent thickness
intercept (in metres) and given that most drillholes dip at -60
lengths * If the geometry of the mineralisation with respect to to -70 degrees from the horizontal, true intersection
the drill hole angle is known, its nature should be widths will be calculated during the block modelling
reported. process.
* If it is not known and only the down hole lengths are
reported, there should be a clear statement to this
effect (eg 'down hole length, true width not known').
=============================================================== =============================================================================
Diagrams
* Appropriate maps and sections (with scales) and * This part will be done once CCZ's current drilling
tabulations of intercepts should be included for any program is completed, and all samples have been
significant discovery being reported These should assayed and verified.
include, but not be limited to a plan view of drill
hole collar locations and appropriate sectional
views. * Appropriate diagrams are presented in the body and
the Appendices of the current ASX Release. Where
scales are absent from the diagram, grids have been
included and clearly labelled to act as a scale for
distance.
* Maps and Plans presented in the current ASX Release
are in MGA94 Zone 54, Eastings (mN), and Northing
(mN), unless clearly labelled otherwise.
* A series of cross-sections are being regenerated at
Big One displaying copper analyses in ppm to aid
interpretation and exploration planning.
.
=============================================================== =============================================================================
Balanced
reporting * Where comprehensive reporting of all Exploration * Comprehensive reporting is planned once CCZ's current
Results is not practicable, representative reporting drilling program has all sample queries returned and
of both low and high grades and/or widths should be have been verified.
practiced avoiding misleading reporting of
Exploration Results.
o Appropriate diagrams are presented in the body and
the Appendices of the current ASX Release. Where scales
are absent from the diagram, grids have been included
and clearly labelled to act as a scale for distance.
* A complete comparison of visual mineralisation
estimated by the site geologist is given in Table
A3-1 at the end of the section. All intersected
intervals are apparent thicknesses in metres.
=============================================================== =============================================================================
Other
substantive * Other exploration data, if meaningful and material, * Several airborne EM and magnetic surveys have been
exploration should be reported including (but not limited to): conducted nearby by historical explorers and Castillo
data geological observations; geophysical survey results; Copper has conducted its own surface sampling program
geochemical survey results; bulk samples - size and prior to drilling commencing as noted above. A major
method of treatment; metallurgical test results; bulk IP survey was completed during May 2021 across five
density, groundwater, geotechnical and rock (5) north-east trending survey lines (dipole-dipole
characteristics; potential deleterious or array). Historical work has focussed on drilling and
contaminating substances. geochemical sampling, with no detailed geophysical
data collection. The copper intersected to date
appears to be associated with a NE-SW trending dyke.
It occurs in two zones - oxidised (malachite, azurite,
tenorite, cuprite) and chalcocite. The aim of the IP
survey was to ascertain if the copper mineralisation
intersected to date has a discernible electrical
response (chargeable and / or conductive). If so, it
is hoped that other zones of similar electrical
response can be highlighted to better focus the
upcoming drill program.
As a result of the evaluation of data from the IP surveys
carried out, the following recommendations are made:
* The 2D section models are likely to give the most
accurate representation of the earth's conductivity
and chargeability variations and should be used when
drill targeting. The 3D model output allows trends
and structures to be mapped and may give some
indications of off-line anomalies.
* Treat anomalies on the edge of lines (and at depth)
with caution. Although care was taken to remove
spurious data, some edge effects may persist in the
data. Before testing any anomalies, GeoDiscovery can
check the raw data to verify if a particular anomaly
likely to be real.
* 50m DP-DP is shown to be a cost-effective method to
cover ground relatively quickly and map the
electrical properties of the top 150m or so. If drill
testing the regions of elevated chargeability proves
successful, a larger 100m DP-DP or P-DP campaign may
be considered to cover more ground and to greater
depth.
* Incorporate the 3D and 2D IP models into the
available geological database to determine the extent
to which the chargeable zones may or may not have
been tested, as well as their geological /
stratigraphic significance.
* It is recommended that where IP anomalies occur near
surface, a field visit is undertaken to see if
anomaly can be explained by surficial clays /
lithology.
=============================================================== =============================================================================
Further work
* The nature and scale of planned further work (e.g., * Future potential work is described within the body of
tests for lateral extensions or depth extensions or the ASX Release, and will include:
large-scale step-out drilling).
o Surface gravity and magnetic surveys, and potentially
* Diagrams clearly highlighting the areas of possible downhole EM surveys.
extensions, including the main geological o Diamond Coring.
interpretations and future drilling areas, provided o Block modelling and wireframing.
this information is not commercially sensitive. o Resource Estimation.
=============================================================== =============================================================================
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