San Lorenzo GOLD the Arco de Oro Target – the “Arc of GOLD”
SAN LORENZO GOLD
THE ARCO DE ORO TARGET – the “ARC of Gold”
CALGARY, AB / April 16, 2024 / San Lorenzo Gold Corp. (TSXV: SLG) (“San Lorenzo”
or “the Company”) is pleased to provide stakeholders a summary of its “Arc of Gold”
target. The target is located within its flagship Salvadora Property in the mega-porphyry
belt of northern Chile.
Summary
San Lorenzo’s “Arco de Oro” – or “Arc of Gold” target is a “hidden gem” located within
the boundaries of San Lorenzo’s 86.6 sq km Chilean Salvadora property.
The “Arc of Gold”, as San Lorenzo’s management refers to it, runs from the mid-
southern edge of the Salvadora property boundary to the upper the north-west property
boundary – a distance of approximately 8 km.
Historically, abundant shallow surface “artisanal” mining has occurred on the Arco de
Oro trend as well as deeper mining from adits at the historical Santa Cecilia mine
located in the northwest quadrant of the trend. The Santa Cecilia mine is reported to
have produced significant amounts of high-grade gold. Numerous shallow surface
artisanal workings are evident all along the trend – in the upper “oxidized layer” of the
system. Those workings serve to delineate the curved feature of the Arc very well and,
of course, guided San Lorenzo’s exploration efforts that consist of sampling, IP, and
drilling.
Due to budget constraints, San Lorenzo has only drilled a small part of the Arco de Oro
trend to date. Those efforts were focused generally in the middle of the trend - in the
general area where the Feliz Retiro trenches are located. Surface and mine trench
sampling conducted by San Lorenzo returned significant gold grades. Those grades
and the type of associated alteration motivated a limited IP program and the drilling of 5
holes in total.
Every one of the 5 holes encountered mineralization with very significant grades of gold
together with copper and silver. Importantly, the last hole drilled, which was a step-out
to the north-west, targeted the vein system at a significantly deeper depth than the first
4 holes. That last hole intercepted the system at a vertical depth of 290 meters
confirming that the veins evident at surface continue to a significant depth – at least in
the area of that hole. The hole encountered disseminated and semi-massive sulphides.
It cut 22.5 meters of mineralization that would be considered significant in that gold
grades averaged 4.74 g/t over 22.5 meters. However, within that interval, grades of
16.27 g/t gold over 6.5 meters were obtained and within that was a high-grade core
zone that cut 58.18 g/t gold over 1.5 meters. Interestingly, the disseminated to semi-
massive pyrite and chalcopyrite were entered at a depth 160 metres in an area where
San Lorenzo’s IP shows an interesting conductivity anomaly.
San Lorenzo is pleased with the results of that hole that confirmed the significant depth
potential of the system.
General Discussion
The Arco de Oro Target is a belt of multiple vein systems that trend in a curved SE to
NW orientation. This belt is characterised by multiple epithermal veins that are evident
at surface. Surface artisanal workings have been extensively sampled at surface and
within shallow artisanal trenches. That sampling, combined with drilling conducted by
San Lorenzo, has confirmed a strike length of over 2 km so far. The curved trend
features the Santa Cecilia mine in the NW quadrant of the trend. Overall, within the San
Lorenzo’s Salvadora property boundary limits, the Arco de Oro trend has artisanal
mining evident at surface for over 5 km.
The trend features many individual vein systems that are several to tens of metres wide
within a belt that is up to 500 meters wide in areas. Drilling has established high-grade
core zones within individual systems. Those grades, when combined with mineralization
encountered in wall rock, may provide overall grades that make the system bulk
mineable. San Lorenzo notes that its limited drilling has not established that to be the
case as of yet.
The most recently drilled hole on Arco de Oro – SAL 04-22 - was designed to test the
system at depth. San Lorenzo was pleased that that hole cut semi-massive sulphides
and returned intercepts with excellent grades. Results confirmed that in that area, the
vein system extends to a depth of at least 290 meters. This was a significant
achievement for San Lorenzo as it provided yet more evidence to management that
Arco de Oro hosts a mineralized system over a long strike length that extends to depth
which presents a combination of scale and grade that may allow San Lorenzo to build a
significant high-grade gold resource - with copper and silver included that will contribute
to the economics of mining in the future.
Prior Sampling
Surface soil geochemical sampling has returned strongly anomalous gold values over
the majority the Arco de Oro trend.
Surface rock chip samples taken from old workings and outcrops along the vein
systems range from 8.2 g/t Au and 15.5 g/t Ag over 0.9 meters all the way up to 154.5
g/t Au and 18.2 g/t Ag over 1.3 meters – again, at surface.
Figure 1 (below) is a map of the Arco de Oro target area. Included are rock chip
sample locations (green) and assay values therefrom. Evident on the map are the
locations of the Feliz Retiro, Arco Primero, Maria Teresa and Santa Cecilia mines. The
only deep mine of those 4 is the Santa Cecilia mine. Also shown are the locations of the
5 holes drilled by San Lorenzo to date (during the 2016 (yellow), 2018 (blue) and 2022
(red) programs).
Prior Mining
Until as recently as 2014, mining on the Arco de Oro trend occurred from an adit at the
Santa Cecilia mine from which the owners reported production of high-grade oxide ore
containing up to 20 g/t of gold. The location of the Santa Cecilia mine is depicted on
Figures 1, 2 and 4. It is located on trend 900 metres to the northwest of the last hole –
SAL 04-22 - drilled by San Lorenzo. Management of San Lorenzo considers it very
reasonable that continued drilling on trend for 900 meters toward the Santa Cecilia mine
– at both shallow and deeper depths on lands 100% owned by San Lorenzo - may yield
a substantial increase in the established strike length of the mineralised system.
Continuing onward past the Santa Cecilia mine in a northwesterly direction, the trend
continues for approximately 3 more kilometers until reaching San Lorenzo’s property
boundary - again with artisanal mining evident along the trend. Management is of the
opinion that San Lorenzo has the potential to define a substantial resource at Arco de
Oro by virtue of the long strike length and having now confirmed that in at least one
area, the vein system extends down to at least 290 meters. Management is also of the
view that continued drilling to the southeast of hole SAL 04-16 – the southeastern most
hole drilled by San Lorenzo to date and where long sections of surface artisanal mining
are evident - is also warranted in that it has the potential to significantly extend strike
length in that direction as well - by as much as 2 additional kilometers until the property
boundary is reached. It is intended that drilling, when conducted, will target the vein
system in the shallower oxidized area and at depth as well – with at least one hole
targeting the system at depths deeper than 290 meters.
Prior Drilling
The three drilling programs carried out to date involved just 5 holes. Three of the holes
were over 400 of strike in the Feliz Retiro vein system and cut high grade gold-copper-
silver mineralization grading 4.55 g/t Au over 7 meters to 11.69 g/t Au over 3 meters at
vertical depths from 50 to 75 metres. A fourth hole focused on the parallel Arco Primero
vein system and retuned an intercept of 9.95 g/t Au over 2 meters. Included in that 2
meter interval were significant copper grades of 0.47% and silver grades of 12.7 g/t.
The fifth hole, which was the most recent hole, was a step out on the Feliz Retiro
system to the north-west which targeted the vein system at a much deeper depth. The
objective was to determine to what depth the vein system evident extended down to.
That SAL 04-22 hole cut semi-massive sulphides at a depth of 290 metres from surface
after having encountered disseminated to semi-massive pyrite and chalcopyrite
beginning at 160 metres of vertical depth. The location of each hole referred to above
can be viewed on Figure 1 with the associated grades presented in Table 1. The
mineralization encountered in hole SAL 04-22 coincides with the conductivity anomaly
identified by San Lorenzo’s IP.
Regarding grades, it is management’s view that the grades encountered on the Arco de
Oro trend would be generally regarded to be very economical to mine and San Lorenzo
may be able to report a large-scale resource on the Arco de Oro with more confirmatory
drilling needed to meet NI 43-101 disclosure requirements.
Table1 (below) highlights the mineralized intercepts from the 5 holes drilled to date by
San Lorenzo on Arco de Oro.
Hole # Vein System From(m) To(m) Width(m) Au g/t Ag g/t Cu %
SAL-04-22 329 351.5 22.5 4.74 3.6 0.18
Feliz Retiro including 333 339.5 6.5 16.27 9.9 0.39
including 335.5 337 1.5 58.18 15.7 0.38
SAL-07-22 Feliz Retiro 100 114.7 14.7 2.52 3.5 0.08
including 100 103 3 11.69 11.6 0.24
SAL-09-22 Primero 97 99 2 9.95 12.9 0.47
SAL-04-18 Feliz Retiro 70 82 12 2.74 2.9 0.27
including 71 75 4 6.48 6.0 0.57
SAL-04-16 Feliz Retiro 109 116 7 4.55 9.2 0.26
Prior Geophysics
San Lorenzo has completed limited IP over the Arco de Oro system. That survey,
completed over the southeastern 60% of the Arco de Oro trend, identified a moderate to
strong underlying chargeability anomaly (see Figure 2 below) from 150m depth which is
open at depth and to the northwest. The sulphide zone intersected in hole SAL 04-22
coincides well with the chargeability anomaly.
Figure 2 (above) depicts the IP lines completed by San Lorenzo over the Arco de Oro trend and
outlines the IP chargeability anomaly area identified by IP (shaded in pink).
Figure 3 (above) illustrates the trend of artisanal workings evident at surface on Arco de Oro
looking north-west.
The 1 hole completed in the 2016 program (yellow) and the 1 hole completed in the 2018
program (blue) and the 3 holes completed in the 2022 program (red) which are evident at the
top of the image depict the location of the only holes drilled by San Lorenzo to date and
demonstrate that San Lorenzo has only conducted drilling on a small portion of the trend evident
at surface from historical artisanal workings.