TIDMCCZ
RNS Number : 2182Z
Castillo Copper Limited
20 May 2021
20 May 2021
Please click the following link to view the figures and
illustrations included in the below announcement:
https://wcsecure.weblink.com.au/pdf/CCZ/02376342.pdf
CASTILLO COPPER LIMITED
("Castillo" or the "Company")
Geophysics survey extends potential mineralisation and
identifies new targets at Big One Deposit
Targets include a significant untested bedrock conductor that is
materially larger than the high-grade anomaly drilled in 2020
Castillo Copper Limited (LSE and ASX: CCZ), a base metal
explorer primarily focused on copper across Australia and Zambia,
is pleased to announce that preliminary interpretations of the
inaugural IP survey at the Big One Deposit have identified multiple
new prospective anomalies along line of lode, including a
significant untested bedrock conductor to the north.
Highlights
-- Increased the potential structural targets across the Big One
Deposit - compelling evidence that significant incremental
mineralisation is located along fault structures rather than
constrained within the trachyte dyke
-- Findings from Line 3 - which is 700m long (Figure 1) -
highlight a significant untested bedrock conductor north of the
line of lode that is materially larger than the high-grade anomaly
drilled in 2020
-- Further, three more untested prospective anomalies along Line
3 were discovered south of the line of lode which collectively
bolster the Big One Deposit's exploration potential
-- Reconciling the IP survey results with all legacy drilling
has boosted the geology team's understanding of the system apparent
at the Big One Deposit:
o Several drill holes need to be extended to deeper depths to
enhance the probability of intersecting underlying copper
mineralisation; and
o New locations and orientations are being made to the next
phase of the drilling campaign - which is due to commence shortly -
in order to achieve optimal results
Figure 1: Line 3 - Newly Identified Bedrock Conductors - refer
to link above
Simon Paull, Managing Director of Castillo Copper, said: "We are
very excited by these geophysics results, which significantly
enhance the exploration potential of the Big One Deposit. The IP
survey provides compelling evidence that known mineralisation
extends beyond the line of lode both to the north and to the south.
This includes an untested bedrock conductor that is significantly
larger than the high-grade anomaly we drilled in 2020. We now have
several new high-priority structural targets for the next phase of
drill testing which is set to commence shortly."
Geophysics Campaign
The recent IP survey comprised six lines, ranging from 500-700m
long, and spaced nominally 200m apart over the 1,200m line of lode
which has been subject to three drilling campaigns over the past
five decades (Figure 2 - refer to link above).
The primary objective of the campaign was to identify massive
new sulphide bedrock conductors along the strike extent and extend
known mineralisation. Further, the geology team wanted geophysical
insights into several known yet under-explored nearby anomalies
that included previously mapped gossanous outcrops to the
north-east of the 2020 drilling campaign and scattered historical
surface stream sediment and rock chip sampling.
Figure 2: Line locations transversing Big One Deposit- refer to
link above
Encouraging Results
In reviewing the results from the IP survey, Line 3 delivered
the most compelling new insights, summarised as follows:
-- A significant, untested bedrock conductor was identified
circa 200m north of the line of lode where last year's high-grade
discovery was located (refer to Figure 1 in link above). Notably,
the newly discovered target is materially larger than the anomaly
intersected in 2020 which produced the following nearby intercepts
(between Lines 2 and 3):
o 303RC: 40m @ 1.64% from (fm) surface incl: 11m @ 4.40% fm 24m,
5m @ 7.34% fm 28m & 1m @ 16.65% fm 29m
o 301RC: 44m @ 1.19% Cu fm surface incl: 14m @ 3.55% fm 27m, 3m
@ 10.88% fm 37m & 1m @ 12.6% fm 37m
-- In addition, south of the line of lode along Line 3, are
three more untested anomalies that build on the Big One Deposit's
exploration potential
One of the key value-add insights was reconciling the geophysics
findings with all legacy drilling results. This enhanced the
geology team's understanding of the underlying system and helped to
identify the following:
-- It is apparent the mineralisation is dictated by emplacement
along structures and not the dyke, as there appears to be
significant chargeability anomalies away from the trachyte dyke,
following lineaments or structural trends
-- Initial observations are that historical drilling in the
southern region has not tested areas of elevated chargeability
(either too shallow or wrong location)
-- Not all chargeable anomalies will reflect mineralisation -
typically clays, uneconomic sulphides and some lithologies such as
shales can give chargeable responses - but certainly the results
from Lines 2 and 3 give some confidence that zones of elevated
chargeability in this region are of interest as drill tested
anomalies have shown significant copper mineralisation
-- The next phase of the drilling campaign, which is due to
commence shortly, is being realigned to intersect newly identified
targets and bolster the chances of achieving optimal results
Next Steps
There are several concurrent next steps that Castillo's teams
are working on:
-- The geophysicist consultant will prepare a 3D model of the IP
survey findings from the Big One Deposit
-- The upcoming drilling campaign will soon be finalised ahead
of the team moving to site to commence work
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:
-- The Mt Oxide project 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: PROSPECTS WITHIN THE MT OXIDE PROJECT
FIGURE A1: MT OXIDE PROJECT - refer to link above
APPIX B: APPIX B: JORC CODE, 2012 EDITION - TABLE 1
The following JORC Code (2012 Edition) Table 1 is primarily
supplied for the provision of explaining the IP Survey 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, * No additional surface or drilling samples have been
random chips, or specific specialised industry collected or assayed as this release talks to the
standard measurement tools appropriate to the recently completed IP ground geophysical survey.
minerals under investigation, such as down hole gamma
sondes, or handheld XRF instruments, etc). These
examples should not be taken as limiting the broad
meaning of sampling.
* Include reference to measures taken to ensure sample
representivity and the appropriate calibration of any
measurement tools or systems used.
* Aspects of the determination of mineralisation that
are Material to the Public Report.
* In cases where 'industry standard' work has been done
this would be relatively simple (eg 'reverse
circulation drilling was used to obtain 1 m samples
from which 3 kg was pulverised to produce a 30 g
charge for fire assay'). In other cases, more
explanation may be required, such as where there is
coarse gold that has inherent sampling problems.
Unusual commodities or mineralisation types (e.g.,
submarine nodules) may warrant disclosure of detailed
information.
================================================================= =========================================================================
Drilling * No new drilling has taken place.
techniques * Drill type (e.g., core, reverse circulation,
open-hole hammer, rotary air blast, auger, Bangka,
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 * No drilling nor samples were taken.
recovery * Method of recording and assessing core and chip
sample recoveries and results assessed.
* Measures taken to maximise sample recovery and ensure
representative nature of the samples.
* Whether a relationship exists between sample recovery
and grade and whether sample bias may have occurred
due to preferential loss/gain of fine/coarse
material.
================================================================= =========================================================================
Logging * No logging took place.
* Whether core and chip samples have been geologically
and geotechnically logged to a level of detail to
support appropriate Mineral Resource estimation,
mining studies and metallurgical studies.
* Whether logging is qualitative or quantitative in
nature. Core (or costean, channel, etc) photography.
* The total length and percentage of the relevant
intersections logged.
================================================================= =========================================================================
Sub-sampling * No drilling nor samples were taken.
techniques * If core, whether cut or sawn and whether quarter,
and sample half or all core taken.
preparation
* If non-core, whether riffled, tube sampled, rotary
split, etc and whether sampled wet or dry.
* For all sample types, the nature, quality, and
appropriateness of the sample preparation technique.
* Quality control procedures adopted for all
sub-sampling stages to maximise representivity of
samples.
* Measures taken to ensure that the sampling is
representative of the in-situ material collected,
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 * Not applicable as no new sampling or assaying took
data and assaying and laboratory procedures used and whether place.
laboratory the technique is considered partial or total.
tests
* 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.
* Nature of quality control procedures adopted (eg
standards, blanks, duplicates, external laboratory
checks) and whether acceptable levels of accuracy
(i.e. lack of bias) and precision have been
established.
================================================================= =========================================================================
Verification
of sampling * The verification of significant intersections by * Not applicable as no new sampling or assaying took
and assaying either independent or alternative company personnel. place.
* 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.
================================================================= =========================================================================
Location
of data * Accuracy and quality of surveys used to locate drill * The survey, as originally proposed, consisted of the
points holes (collar and down-hole surveys), trenches, mine following IP work (as per the survey plan on the next
workings and other locations used in Mineral Resource page; Figure A2-1) six 6 lines each 500m in length
estimation. with 50m dipoles, totalling 3km.
* Specification of the grid system used. * Fender Geophysics had noted in their quote that the
methodology may be changed to Pole-Dipole if it is
felt this will give better results. Given the line
* Quality and adequacy of topographic control. length and depth of the area of interest (150-200m)
Fender planned to extend the transmitter sites out by
4 dipoles on the southeast end of the lines to
increase depth penetration at that end.
* The spatial location for these holes has been
differentially surveyed into MGA94 - Zone 54. Collar
heights are to the Australian Height Datum.
Figure B1 IP Survey Line Location (refer to link above)
================================================================= =========================================================================
Data spacing
and * Data spacing for reporting of Exploration Results. * The scope of works for the survey is given below:
distribution
* Whether the data spacing and distribution is o Array: Dipole-Dipole (roll-along)
sufficient to establish the degree of geological and o Receiver Dipole Length: 50 m
grade continuity appropriate for the Mineral Resource o Transmitter Dipole Length: 50 m
and Ore Reserve estimation procedure(s) and o Domain and Cycle: Time domain - 2 seconds or 0.125
classifications applied. Hz
o Line Length: 500 m
o Number of Lines: 6
* Whether sample compositing has been applied. o Line kms: 3.0 km
================================================================= =========================================================================
Orientation
of data * Whether the orientation of sampling achieves unbiased * Fender Geophysics (Fender) was contracted to complete
in relation sampling of possible structures and the extent to a program of Dipole-Dipole array IP survey work for
to which this is known, considering the deposit type. Castillo Copper Limited at the Big One deposit
geological located within Castillo's Mt Oxide Project in the Mt
structure Isa copper belt (EPM 26574), approximately 170km
* If the relationship between the drilling orientation north of Mt Isa (see location map below; Figure
and the orientation of key mineralised structures is A2-2). Most of the interpretation comments have been
considered to have introduced a sampling bias, this provided by Ms Kate Nelson of GeoDiscovery.
should be assessed and reported if material.
Figure B2 Survey General Location (refer to link above)
* The core objectives of the survey were to identify
massive sulphide bedrock conductors along the 1,200m
strike extent that potentially extends known
mineralisation and provide geophysical insights into
several known yet underexplored nearby anomalies
which includes previously mapped gossanous outcrops
to the north-east of the recent drilling campaign
conducted in Q4 2020.
================================================================= =========================================================================
Sample * No new samples were taken.
security * The measures taken to ensure sample security.
================================================================= =========================================================================
Audits or
reviews * The results of any audits or reviews of sampling * The data was collected by Fender Geophysics, with the
techniques and data. data reduction and modelling being conducted by
GeoDiscovery, both independent contractors to
Castillo Copper
================================================================= =========================================================================
Section 2 Reporting of Exploration Results
(Criteria listed in the preceding section also apply to this
section.)
Criteria JORC Code explanation Commentary
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, and as illustrated by Figure A2-3.
historical sites, wilderness or national park and
environmental settings.
o EPM 26574 (Valparaisa North) - encompasses the Big
One historical mineral resource, Holder Total Minerals
* The security of the tenure held at the time of Pty Ltd, granted 12-June-2018 for a 5-year period over
reporting along with any known impediments to 100 sub-blocks (323.3Km(2) ), Expires 11-June-2023.
obtaining a licence to operate in the area. o EPM 26462 (Big Oxide North) - encompasses the 'Boomerang'
historical Prospect 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) - Granted on the 08-March-2021
over 70 sub-blocks (215Km(2) ) by Castillo Copper
Limited. Expires 7(th) March 2026.
Figure B3 Castillo Copper Prospects (refer to link
above)
* A check on the tenures in 'application status' was
completed in 'GeoResGlobe' on the 15th May 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 ASX releases' reference lists):
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 * This ASX release concerns itself with geophysical
understanding of the exploration results including a survey whereas previous ASX releases have discussed
tabulation of the following information for all the 2020 drilling program in detail.
Material 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 * In reporting Exploration Results, weighting averaging * The new work was a ground geophysical dipole-dipole
methods techniques, maximum and/or minimum grade truncations IP survey so there was no sample to aggregate.
(e.g., cutting of high grades) and cut-off grades are
usually Material and should be stated.
* Where aggregate intercepts incorporate short lengths
of high-grade results and longer lengths of low-grade
results, the procedure used for such aggregation
should be stated and some typical examples of such
aggregations should be shown in detail.
* The assumptions used for any reporting of metal
equivalent values should be clearly stated.
================================================================= =============================================================================
Relationship
between * These relationships are particularly important in the * The strike of the dyke is at 73 degrees (east) and
mineralisation reporting of Exploration Results. variably 70-85 degrees dip to the south. The
widths and mineralised zones for copper (>500ppm) interested in
intercept drillholes range from 1m to 44m wide apparent,
lengths * If the geometry of the mineralisation with respect to averaging 9m apparent (6.8m true width). The IP
the drill hole angle is known, its nature should be survey was designed to intersect the strike of the
reported. mineralisation at a perpendicular angle.
* If it is not known and only the down hole lengths are * All mineralised intervals (i.e., >500ppm) have been
reported, there should be a clear statement to this reported in this and previous ASX releases as the
effect (eg 'down hole length, true width not known'). "as-intersected" apparent thickness (in metres) and
given that most drillholes dip at -60 degrees from
the horizontal, true intersection widths will be less,
but will be calculated during the block modelling
process.
================================================================= =============================================================================
Diagrams
* Appropriate maps and sections (with scales) and * Appropriate diagrams are presented in the body and
tabulations of intercepts should be included for any the Appendices of the current ASX Release. Where
significant discovery being reported These should scales are absent from the diagram, grids have been
include, but not be limited to a plan view of drill included and clearly labelled to act as a scale for
hole collar locations and appropriate sectional distance.
views.
* 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 were generated at Big One
displaying copper analyses in ppm to aid
interpretation and exploration planning as can be
seen in Figure A2-4, below, which shows the
geological section through which IP Line 3 traverses.
Figure B4: North-South Cross-section at BO_306RC (refer
to link above)
================================================================= =============================================================================
Balanced
reporting * Where comprehensive reporting of all Exploration * All survey lines except Line 6 which was scrapped in
Results is not practicable, representative reporting favour of extending Line 3 will be presented once
of both low and high grades and/or widths should be fully interpreted. Line 2 is discussed at the end of
practiced to avoid misleading reporting of this section.
Exploration Results.
================================================================= =============================================================================
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.
method of treatment; metallurgical test results; bulk
density, groundwater, geotechnical and rock
characteristics; potential deleterious or * As a result of further examination CCZ's geology team
contaminating substances. made the following recent key interpretations:
o The full assay results, which included the entire
twenty-one (21) drill-holes completed are awaiting
some clarifications and re-assay of composites before
a complete assessment of the data can be made and reported.
o The presence of at least two mineralised lenses and
a low-grade halo (100-1,500ppm) around the main ore
body appears to hold along strike.
o For drill-holes 213RC, 301RC, 303RC, 307RC, and 313RC
the mineralisation is spread out which is significant
given the trachyte to diorite dyke is generally 4-6m
wide (refer Figure 1).
o There is more than one dyke, however they may be
offshoots of the main body. Compositions vary as rock
types logged from the chips in both 1993 and the current
campaign include trachyte, diorite, and granite (more
probably a porphyritic syenite).
o Some of the drillholes will need to be deepened (or
used as a seed hole for downhole EM) as they appear
not to have been drilled deep enough to intersect the
projected dyke at depth. The affected holes are 201RC,
202RC, 203RC, and 304RC.
o Planning for the IP Survey highlighted more target
areas near Big One to the south and south-west where
there are more trachyte dyke swarms that could be affected
by structural control.
================================================================= =============================================================================
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 Conduct a review all the IP lines (and integrating
* Diagrams clearly highlighting the areas of possible the assay data, known geology / geological model) to
extensions, including the main geological assess potential IP targets (as only 2 of the 6 IP
interpretations and future drilling areas, provided lines acquired to date). Geological mapping and rock
this information is not commercially sensitive. chip sampling over the anomalous chargeability zones
along each survey line
o Ground gravity and/or magnetic surveys.
o Reverse Circulation Drilling
o Diamond Coring.
o Block modelling and wireframing.
o Resource Estimation.
================================================================= =============================================================================
Appendix C: IP Line 2 Preliminary Discussion
Figure C1 shows a preliminary model of the first line of IP data
collected (Line 2 - 10500). Note it is a preliminary model - in a
new region it can take a couple of lines of data to refine some of
the model parameters.
As lines are not east-west or north-south, data is being
acquired in a local grid (which is needed in the modelling
software). Once data has been acquired and modelled, it can be
converted back to MGA space.
Figure C1: Line 2 IP Resistivity compared to Chargeability.
(refer to link above)
Figure C1 displays the preliminary model for this line - the top
image is a resistivity depth section (warm colours resistive and
cool colours more conductive), the bottom image displays the
chargeability depth model (higher chargeability's displayed in warm
colours).
A few notes on the output to date:
-- The section runs from NW-SE. The mineralisation and drilling
to date is located between 5300 and 5250.
-- The top resistivity model depicts a generally resistive
environment. Some higher conductivity features are noted near
surface between 5300 - 5100, which may reflect clays in
topographically lower regions? Of interest, extending to depth
(near vertically) at 5300 is a zone that displays an increase in
conductivity - possible structure / dyke /? Note - this zone of
increased conductivity does not directly correspond to the higher
chargeability's (typical response of massive sulphides).
-- The bottom chargeability model ranges between 0 - 10mV/V (low
to moderate). A moderate IP anomaly is noted 5275 at around 20 -
40m depth (dipping towards the SE). If this is the electrical
signature of the known mineralisation at this location, we are
looking at a resistive and moderately chargeable response adjacent
to a steeply dipping zone of higher conductivity.
-- Some regions of moderately high chargeability are noted near
surface between 5150 - 5050. It would be worthwhile field checking
this region to see if this near surface chargeable response can be
explained. This region overlies a low chargeable / resistive
response which may reflect the magnetic intrusions (heat / fluid
source?).
-- Note - higher chargeable values are also noted to the NW of
the dyke 5400 - 5350. Mark, I understand that you initially
believed this region to be less prospective. Is there anything in
the mapped geology that could explain the chargeable response? If
it is not easily explained - I would recommend extending line 1 to
the NW, particularly as the magnetic model indicates the presence
of a weak response near surface in this region.
-- Typically, massive sulphides give a conductive and chargeable
response and more disseminated sulphides display a resistive and
chargeable response. The more oxidised Cu may be weakly
chargeable.
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