Orosur Mining Inc – High grades continue at Pepas, El Cedro prospectivity developing.
Orosur Mining Inc – High grades continue at Pepas, El Cedro prospectivity
developing.
• Assays for six more holes from the Pepas MRE infill program include:
o PEP054 - 20.6m @ 2.01g/t Au
o PEP055 - 47.25m @ 15.25g/t Au
o PEP056 - 22.5m @ 1.64g/t Au
o PEP057 - 7.45m @ 3.05g/t Au and 17.1m @ 5.47g/t Au
o PEP058 - 34.85m @ 3.24g/t Au
• El Cedro soil program producing exceptional results.
London, September 9th, 2025. Orosur Mining Inc. (“Orosur” or the “ Company”)
(TSXV/AIM:OMI), is pleased to announce an update on the progress of exploration
activities at the Company’s flagship , 100% owned, Anzá Gold Project (“Project”) in
Colombia.
Anzá - Colombia
As announced on 14th July 2025, the Company took the formal decision to commence
infill drilling at its Pepas gold prospect at Anzá, with the objective of moving Pepas to
a NI43-101 compliant Mineral Resource Estimate (“MRE”) by the end of the year.
These six holes announced today are a continuation of this program and designed
largely to infill to the required spacing to allow an MRE to be calculated to a high level
of confidence, and to define and understand the nature of the ore body margins and
mineralising controls.
Results from these holes continue to firm up the Pepas orebody and provide better
definition of the nature of the thick, high -grade mineralisation . Recent results are
largely as expected in terms of the grade distribution across Pepas. However, PEP055
unexpectedly intersected an extremely high-grade vein at a downhole depth of only
30m, well beyond the grades that have thus far been encountered. While only narrow
(1.9m downhole width), this vein could be significant, and more work will be required
to understand its extent and thus its geological and MRE significance.
The MRE infill drill program is ahead of schedule, and subject to a mid-program review,
could be completed by late October 2025. Once complete, the rig will then move back
to exploration, either around Pepas, or at the APTA prospect to better understand the
newly evolving geological model there. This decision will be made in coming weeks.
A comprehensive metallurgical test program is currently being developed for Pepas,
with discussions underway with several laboratories in South and North America.
These plans are hoped to be finalised soon, and it is anticipated that one or two wider
diameter (PQ) metallurgical holes will be required to provide the necessary weight of
material for testing.
Hole Number From (m) To (m) Interval (m) Au (g/t)
PEP054 20 40.6 20.6 2.01
including 33.1 39.6 6.5 3.29
PEP055 22.05 69.3 47.25 15.25**
Including 27.85 41.8 13.95 45.99**
Including 29 30.9 1.9 303.25**
PEP056 6 28.5 22.5 1.64
including 22.8 28.5 5.7 3.78
PEP057 2.95 4.85 1.9 1.19
10.85 18.3 7.45 3.05
including 10.85 12.5 1.65 12.31
29.8 46.9 17.1 5.47
including 32.85 41.1 8.25 8.85
including 35.8 37.8 2 26.55
PEP058 9.75 18.65 8.9 0.62
32.95 67.8 34.85 3.42
including 38.9 59 20.1 4.7
PEP059 13.4 27.6 14.2 0.75
Table 1. Latest drill Intercepts, Pepas Prospect
** see section below on coarse gold
Figure 1. Plan of holes
Figure 2. Section, PEP054, 055
Figure 3. Section PEP056, 057, 058, 059
Coarse Gold – PEP055
The quoted composite assay result from PEP055 of 47.25m @ 15.25g/t Au has been
influenced by two consecutive high-grade samples across 1.9m in which visible gold
was noted in core . These two consecutive samples returned 465.71g/t Au and
122.74g/t Au respectively. Outside these two samples, grades assayed were largely
in line with adjacent holes.
The Company feels that these two samples represent a real, and very high-grade vein,
but are also cognisant that coarse gold has the potential to create a sampling bias if
incorrect sample preparation has resulted in heterogenous distribution of gold
throughout the sample.
To assess the potential impact of this, pulps from these two samples were re-assayed
twice, with reasonably consistent results (table 2). The Company is therefore confident
that no significant sampling bias has occurred. Geologically however, such high-grade
samples are a statistical outlier and will require further understanding so that their
impact on a MRE is accurately reflected.
Sample Original assay Re-assay 1 Re-assay 2
Sample 1 - 1m 465.71ppm 453.19ppm 478.23ppm
Sample 2 - 0.9m 122.74ppm 121.16ppm 124.33ppm
Table 2. Coarse gold re-assay
El Cedro - Anzá, Colombia
The El Cedro prospect is a large gold porphyry/epithermal system, located toward the
south of the Anzá project, on the same granted exploration title as the Pepas and
APTA deposits.
El Cedro had been explored in cursory fashion by Anglo American, prior to Orosur
taking ownership of the Project in late 2014 , with a dditional mapping and ground
geophysics then carried out by the Company’s previous JV partner MMA in 2022 and
2023.
No drilling has ever been undertaken on the prospect.
The region has sparse outcrop, but a large porphyry system had been identified and
roughly defined from regional mapping and more recent airborne magnetic and
radiometric data. Several phases of soil geochemical surveys were carried out in the
centre of the prospect, around a central core of potassic alteration visible from airborne
radiometrics, and in nearby creeks where fresh rock had been exposed.
A large area of anomalous soils was historically sampled in the centre of the prospect
with numerous high grade rock chip and channel samples of between 1 and 9 g/t Au
in surrounding creeks in later stage polymetallic veins (Figure 4).
To better define the scope and nature of El Cedro, the Company recently commenced
a wider scale ridge and spur soil sampling program over the entire extent of what is
thought to be the porphyry system. Being rugged terrain, sampling was limited to
ridges and spurs to ensure that sampled material is residual and insitu.
Figure 4. El Cedro prospect– previous sampling (Anglo and MMA) and sampling plan
After a brief pause due to limited access during the wet season, this program has
recommenced and is now approximately 65% complete.
Figure 5. Orosur soil sampling, El Cedro - progress
Gold assay results thus far are highly encouraging with large areas of over 0.3g/t Au
and at times over 1g/t Au being identified in soils and saprolite around a central core.
Geological mapping being undertaken in conjunction with the soil program is also now
better defining the porphyry system and the associated vein systems. Base metals
associations have also been noted in outcrop, however, base metal assays require a
different assay method not available in Colombia and these will require several weeks
to be returned.
The Company feels the ongoing work program is showing El Cedro as a complex and
highly prospective gold porphyry system. Once this current program is complete in
coming weeks, all data will be compiled with a view to planning the next phase of work,
which could involve drilling.
Orosur CEO Brad George commented:
“The Anza Project continues to develop and broaden in scope. Pepas is progressing
toward MRE as planned, but the results at El Cedro are showing this licence has much
more to give”.
Colombia - ANZÁ Project
The Anzá Project is now 100% owned by the Company following completion of a
Share Purchase Agreement ( “SPA”), announced 28 th November 2024, whereby the
Company purchased all of the shares of its previous JV partner; Minera Monte Aguila
(“MMA”).
The Project, which is located 50km west of Medellin , is easily accessible and boasts
excellent infrastructure including water, power and communications as well as a large
exploration camp.
From September 2018 to November 2024, the Anzá Project was under the control of
its previous JV partner MMA, itself a 50/50 venture between the world ’s two largest
gold miners, Agnico Eagle Mines and Newmont Mining.
Prospects
The Company is currently focussed on three prospects within the Anzá Project –
Pepas, APTA and El Cedro. All three prospects are within the same granted
exploration title that is broken into two, non-contiguous pieces (Figure 5)
Drilling is currently being undertaken at the Pepas prospect in the northern extent of
the Anzá Project (pre-acquisition) over 10km north of the central base camp at APTA.
In parallel, mapping and sampling is being undertaken over the El Cedro porphyry
system in the south of the project area.
Figure 6. Main prospects, licences pre-MMA acquisition
Holes Drilled post MMA Transaction
48 holes have been drilled at Pepas since the MMA Transaction in November 2024.
Assay results are tabulated below.
Hole Number From (m) To (m) Interval (m) Au (g/t)
PEP012 0 66.75 66.75 5.64
PEP013 0 77.30 77.30 7.68
PEP014 0 75.1 75.1 5.58
PEP015 23.5 63.7 40.2 3.75
PEP016 61.6 105.3 43.7 3.13
PEP017 56.1 96.3 40.2 2.06
PEP018 0 54.1 54.1 6.01
PEP019 0 44.3 44.3 1.63
PEP020 0 54.65 54.65 1.94
PEP021 0 107.05 107.05 6.22
PEP022 0 76.3 76.3 7.24
PEP023 0 15 15 1.7
PEP024 9.24 15.6 6.35 1.99
PEP025 0 10.1 10.1 1.45
16.5 79 62.5 5.4
PEP026 0 14.8 14.8 0.57
43.6 72 28.4 2.52
PEP027 1 80.15 79.15 2.0
PEP028 29.5 60.85 31.35 1.61
PEP029 0 30.7 30.7 0.31
PEP030 0 77.9 77.9 0.32
115.6 122.6 7 0.31
PEP031B 28.15 41.1 12.95 0.73
74.1 95.9 20.8 0.3
PEP032 0 92 92 1.68
PEP033 0 21.3 21.3 5.88
PEP034 36 95 59 10.15
PEP035 0 11.4 11.4 2.71
PEP036B 0 40.45 40.45 0.62
PEP037 0 3 3 0.65
PEP038 0 16.8 16.8 0.68
PEP039 No significant intersections
PEP040 0 10.25 10.25 1.35
PEP041 34.35 66.1 31.75 2.01
PEP042 104.8 107.55 2.75 1.41
116.45 119.7 3.25 4.89
PEP043 No significant intersections
PEP044 5.8 44.3 38.5 6.01
PEP045 9.5 71.8 62.3 12.76
PEP046 0 53.2 53.2 3.36
PEP047 0 104 104 6.61
PEP048 0 32.3 32.3 3.65
PEP049 0 94.2 94.2 3.74
PEP050 0 34 34 2.33
PEP051 0 7.4 7.4 0.43
11.2 72.5 61.3 3.36
PEP052 0 4.4 4.4 2.24
9.4 81.25 71.85 6.13
PEP053 17 27.1 10.1 0.9
PEP054 20 40.6 20.6 2.01
PEP055 22.05 69.3 47.25 15.25
PEP056 6 28.5 22.5 1.64
PEP057 10.85 18.3 7.45 3.05
29.8 46.9 17.1 5.47
PEP058 32.95 67.8 34.85 3.42