Starcore Updates on Geophysical Survey (IP and Ground Mag) at Kimoukro Gold Project in Cóte d’Ivoire
______________________________________________________________________________
Suite 750 – 580 Hornby Street, Box 113, Vancouver, British Columbia, Canada V6C 3B6 Telephone: (604) 602-4935 Fax: (604)
602-4936 e-mail. [email protected] website: www.starcore.com
April 4, 2025 TSX: SAM
FSE: V4JA
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Starcore Updates on Geophysical Survey (IP and Ground Mag)
at Kimoukro Gold Project in Cóte d’Ivoire
Vancouver, B.C. - Starcore International Mines Ltd. (TSX: SAM) (“Starcore” or the “Company”) is
pleased to announce results of the Induced Polarisation and Resistivity and ground Magnetic survey (the
Geophysical survey) carried out on its Kimoukro gold project in the central Ivory Coast, some 30 km south
of the country’s capital, Yamoussoukro.
SAGAX Afrique sarlu (“Sagax”), under supervision of Mr. Jean David, completed the IP and ground mag
program in early October, 2024; the survey covered an area of 5,3 km2 measuring 55 line-kilometers over
34 lines, 100 m apart and oriented N105°. An additional 6 lines were surveyed for Mag but not for IP due
to their short extension.
The geophysical survey was designed to identify IP and resistivity anomalies and highlight structural
features to help the interpretation. Multiple moderate-to-strong chargeability anomalies were detected by
the Induced Polarization survey from which high priority drill targets will be generated , considering
different degrees of resistivity, structural interpretation and geology information.
The final report and recommendation were received recently from Sagax.
Ground Magnetic Survey
The ground magnetic survey was carried out over the same lines of IP survey; acquisition conditions were
good and no significant noise results in the data.
The magnetic survey highlights three main different domains.
The hi-magnetic intensity recorded in the northeast part of the grid corresponds to a granite -tonalite
intrusion and immediate surrounding; the shape of the intrusion is irregular; diffuse demagnetisation in this
area is likely the effect of cataclastic deformation and leaching.
______________________________________________________________________________
Suite 750 – 580 Hornby Street, Box 113, Vancouver, British Columbia, Canada V6C 3B6 Telephone: (604) 602-4935 Fax: (604)
602-4936 e-mail. [email protected] website: www.starcore.com
The central part of the grid is interpreted as a strong deformation zone; according to field data, the zone
characterises for highly sheared metasediments and a network of felsic dykes, structurally controlled with
NNW prevailing trend, well depicted by the vertical derivative map.
The south-west portion of the grid marks a lithology change, likely to more basaltic-andesitic rocks, or to
the alteration halo of the southwestern granitic intrusion.
The pattern of the magnetic lineaments shows different characteristics in the different domains, suggesting
local structural complexity; dyke swarms are highlighted by higher magnetic intensity. An apparent circular
feature occurs in the central part of the permit and could potentially be interpreted as an intrusion. Although
no evidence is yet available, this is a possible explanation for the circular feature , as the area underwent
intrusive episodes as demonstrated by the two granitoid intrusions, only 3 km apart, and a set of felsic
dykes, which characterise the Kimoukro project.
Three major structural trends are depicted by magnetic anomalies: one prominent NE striking lineament is
evident in the central part of the grid, and it could be related to a dyke and a fault zone; the NW to N
trending lineaments are consistent wi th remote -sensing structural interpretation , and same trend of
structures is confirmed in the few outcrops. They are interpreted as shear zones, while E-W to NE smaller
lineaments are higher order structures on this system. Shear quartz-veins are at least locally, parallel to the
main shear direction, or within foliation planes. In the NE of the survey grid, at the contact zone and inside
the granite bodies, the veins trend mostly N130 (NW-SE) and there are no straight corresponding magnetic
signals.
Pole-Dipole survey
The pole-dipole survey allowed us to represent resistivity and chargeability along 2D profiles; pseudo-3D
inversion technique was used to populate 3D grids and image the spatial distribution of the electric
parameters. The quality of the survey was good and with good penetration, and allowed for imaging over
200 m depth with good resolution.
In the resistivity map, a persistent resistivity corridor is evident in the central part of the grid, striking NW
to NNW; this zone is also surrounded by parallel conductive layers . This signature is interpretated as a
structural corridor, likely a wide shear zone, whose flanks are coincident with hydrothermal alteration and
host mineralised structures. The NE side of the grid corresponding to the granite-tonalite intrusive and its
nearby surroundings, has moderately high resistivity values from surface ; in contrast, metasediments and
basaltic rocks in the area, are usually conductive down to some 50 m depth. Linear, consistent high
resistivity values are tentatively correlated to strong silica alteration, hence promising for veining. The trend
of most veins inferred in the field is consistent with N to NNW and NW IP axes.
______________________________________________________________________________
Suite 750 – 580 Hornby Street, Box 113, Vancouver, British Columbia, Canada V6C 3B6 Telephone: (604) 602-4935 Fax: (604)
602-4936 e-mail. [email protected] website: www.starcore.com
The chargeability (IP) map shows high chargeable values in the norther n side of the grid, noticeably the
north-east side, where granite crops out, and artisanal miner ’s activity is intense . The high chargeability
values continue westwards, with axes of the peak anomalies, NE and N trending. A high-chargeable zone
is present at the eastern edge of the permit and is open to S-SE, and corresponds to perspective zone with
artisanal mineworks. A prominent N to NNW oriented high chargeability zone marks the central part of the
grid, within sheared metasediments; this insulated anomaly is on the west flank of the structural corridor
and it may mark sulphide zone, hence it is perspective for exploration.
Both the chargeable and resistive anomalies show good continuity and are open at depth. The distribution
and orientation of the chargeable zones fit with a structural model with NNW trending structural corridor,
with apparent sinistral shear sense.
Figure 1 shows Magnetic, IP and Resistivity maps according to the Sagax’s modelling.
FIGURE 1: Sagax’s elaboration: Mag and IP maps
______________________________________________________________________________
Suite 750 – 580 Hornby Street, Box 113, Vancouver, British Columbia, Canada V6C 3B6 Telephone: (604) 602-4935 Fax: (604)
602-4936 e-mail. [email protected] website: www.starcore.com
In similar Birimian terrains, t he chargeable anomalies characterized by medium to high amplitude
resistivity without direct magnetic association, commonly indicate vein-hosted mineralisation, or they mark
the edge of the high magnetic domain. Anomalies characterized by a moderate to high chargeability
response and a decrease in resistivity, generally correspond to mineralization of the deformation zones.
Thirteen main chargeability lineaments have been highlighted in the Sagax; they often correspond with
resistivity axes, suggesting mineralisation in the form of veins and associated silicification. The Sagax’s
proposed exploration targets are at highest IP anomalies and at structural intersection, with priority for the
stronger IP signature; chargeability values over the suggested targets range from 5.6 to 10 mV/V.
FIGURE 2 – Map showing exploration targets proposed by Sagax over IP anomalies and structural
intersections
______________________________________________________________________________
Suite 750 – 580 Hornby Street, Box 113, Vancouver, British Columbia, Canada V6C 3B6 Telephone: (604) 602-4935 Fax: (604)
602-4936 e-mail. [email protected] website: www.starcore.com
ArsTerra’s independent modelling
Independent processing and interpretation were also completed by Dr. Paolo Costantini, principal
geophysicist at ArsTerra Exploration GmbH , who originally suggested the configuration for data
acquisition. Modelling was performed from raw data after data check, and application of corrections, filters
and smoothening, and the final model derive d from inversion of c orrected polarization and resistivity
profiles. The derived maps and slices of the 3D models (Figure 3) differ in several details from previous
modelling; however, the main lineaments, trend of structural corridors, and moderate to high polarization,
are in reasonable agreement and in good part, the two models overlap.
The ArsTerra’s modelling also provides classifications by combining electric and magnetic properties,
translated to rock groups or classes, having specific compaction index, and metal factor indicators . In
addition, the interpretation is corroborated by airborne radiometric dataset and supported by geology data
including magnetic susceptivity measurements on 31 rock samples, progress in geology and assay. The
structural interpretation from both magnetic and IP survey highlights northerly trending structural shear,
and several NW, NE, and WNW -oriented structures which in part are coincident with inferred trace of
mineralised veins.
ArsTerra highlights six (6) muti-linear targets for further exploration ; the targets are traced over the axes
of IP anomaly; priority is based on persistence of the signal and rock classification by metal factor, as well
as magnetic response.
______________________________________________________________________________
Suite 750 – 580 Hornby Street, Box 113, Vancouver, British Columbia, Canada V6C 3B6 Telephone: (604) 602-4935 Fax: (604)
602-4936 e-mail. [email protected] website: www.starcore.com
FIGURE 3: ArsTerra’s Mag and IP-resistivity slices
______________________________________________________________________________
Suite 750 – 580 Hornby Street, Box 113, Vancouver, British Columbia, Canada V6C 3B6 Telephone: (604) 602-4935 Fax: (604)
602-4936 e-mail. [email protected] website: www.starcore.com
FIGURE 4 - ArsTerra's interpretation map with slice of cluster class, structural interpretation and targets,
labelled by priority group
______________________________________________________________________________
Suite 750 – 580 Hornby Street, Box 113, Vancouver, British Columbia, Canada V6C 3B6 Telephone: (604) 602-4935 Fax: (604)
602-4936 e-mail. [email protected] website: www.starcore.com
Besides the differences in details, related to the different processing techniques, the data quality was
confirmed to be very good ; the two independent modelling and interpretation by Sagax’s and ArsTerra’s
seasoned and renowned specialists ended with consistent conclusions in the identification of IP anomalies
and structural interpretation, as well as generation of targets for exploration. The latter is obvious at the NE
intrusive contact zone and its alteration halo; high IP anomaly stretches NE-SW for 2 km and 400 m width,
and is open at both extremities. The eastern limit of the permit is over a linear high chargeable corridor
some 150 m wide, 1800 m long, starting from south of the granite-tonalite intrusion. The high IP anomaly
is open to the south; exploration interest is supported by evidences of mineralised veins and artisanal
prospecting and mineworks. The IP anomaly in the central part of the survey grid spans 750 x 600 m; this
anomaly feature looks associated to a NNW-trending large structural feature (tentatively, a sinistral shear
zone) which is potentially mineralised and hence deserves further investigation. The SW side of the permit
has a different magnetic and electric signature, with higher magnetic amplitude than the central part, but
less prominent IP anomalies. Targets are suggeste d at structural intersections with IP crest values; in
addition, exploration follow-up will consider intrusive contacts and gold occurrences, at little distance from
the SW end of the geophysical survey.
By compiling the information available, priority zones have been narrowed to drill target areas, to be used
to refine a drilling program, as shown in figure 5.