OSISKO DEVELOPMENT INTERCEPTS 65 GRAMS PER TONNE GOLD OVER 4.57 METERS IN UNDERGROUND DRILLING AT TRIXIE, TINTIC PROJECT 65.00 g/t Au and 344.39 g/t Ag over 4.57 m in Drilling 30.17 g/t Au and 62.76 g/t Ag over 1.34 m in Underground Chip Sampling
NYSE: ODV TSXV: ODV NEWS RELEASE
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OSISKO DEVELOPMENT INTERCEPTS 65 GRAMS PER TONNE GOLD OVER 4.57 METERS
IN UNDERGROUND DRILLING AT TRIXIE, TINTIC PROJECT
65.00 g/t Au and 344.39 g/t Ag over 4.57 m in Drilling
30.17 g/t Au and 62.76 g/t Ag over 1.34 m in Underground Chip Sampling
Montreal, Québec, July 18, 2023 – Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko
Development" or the "Company") is pleased to announce underground infill and exploration diamond
drilling ("DD") and chip sampling results from new development areas as part of its ongoing exploration
program at its 100%-owned Trixie test mine ("Trixie"), within the Company's wider Tintic Project (" Tintic"
or the "Tintic Project"), located in the historic East Tintic Mining District in central Utah, U.S.A.
Chris Lodder, President of Osisko Development, commented, "The new underground drill results at
Trixie have identified several previously unknown mineralized structures that extend existing zones. This
enables us to start to plan underground development in those areas for future resource delineation and
category conversion. Underground face chip sample results continue to define mineralized zones, namely
below the main 625 level, down to and below the 750 level, as well as further to the south of the deposit
approaching the Sioux Ajax fault, within our current drill areas."
DRILL ASSAY HIGHLIGHTS
This news release includes assays from 14 DD holes (refer to Table 1). Select assay highlights include:
• 65.00 grams per tonne ("g/t") gold ("Au") and 344.39 g/t silver ("Ag") over 4.57 meters ("m") in
TRXU-DD-23-026 (1.90 troy ounce per short ton ("oz/t") Au and 10.04 oz/t Ag over 15.00 feet ("ft."))
• 5.09 g/t Au and 132.85 g/t Ag over 5.33 m in TRXU-DD-23-027 (0.15 oz/t Au and 3.87 oz/t Ag over
17.50 ft.)
• 15.91 g/t Au and 368.00 g/t Ag over 1.07 m in TRXU -DD-23-030 (0.46 oz/t Au and 10.73 oz/t Ag
over 3.50 ft.)
• 18.91 g/t Au and 300.00 g/t Ag over 0.91 m in TRXU -DD-23-030 (0.55 oz/t Au and 8.75 oz/t Ag
over 3.00 ft.)
• 19.01 g/t Au and 124.00 g/t Ag over 1.22 m in TRXU-DD-23-033 (0.55 oz/t Au and 3.62 oz/t Ag
over 4.00 ft.)
UNDERGROUND CHIP SAMPLE ASSAY HIGHLIGHTS
This news release includes assays from 55 underground exploration face, back and rib chip samples from
20 chip strings in development at Trixie (refer to Table 2). Selected assay highlights include:
• 23.30 g/t Au and 54.38 g/t Ag over 1.65 m in CH01519 (0.68 oz/t Au and 1.59 oz/t Ag over 5.40
ft.) including
o 51.22 g/t Au and 79.81 g/t Ag over 0.64 m in CH01519 (1.49 oz/t Au and 2.33 oz/t Ag over
2.10 ft.)
• 30.17 g/t Au and 62.76 g/t Ag over 1.34 m in CH01527 (0.88 o z/t Au and 1.83 oz/t Ag over 4.40
ft.)
• 16.29 g/t Au and 128.34 g/t Ag over 1.01 m in CH01529 (0.48 oz/t Au and 3.74 oz/t Ag over 3.30
ft.)
• 7.50 g/t Au and 158.58 g/t Ag over 2.01 m in CH01530 (0.22 oz/t Au and 4.63 oz/t Ag over 6.60
ft.)
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DRILL RESULTS SUMMARY
• In 2023, the Company has drilled 60 holes for a total of 5,180 m (17,000 ft.) at Trixie.
• Approximately 25% of the drilling to date consists of delineation of domains within the area of the
current Trixie Mineral Resource Estimate ("Trixie MRE") and 75% is exploration drilling adjacent
to the area of the current Trixie MRE, including step outs down dip, down plunge and along strike
testing for mineralized structures.
• Visible gold and dissemi nated pyrite in fault breccia was observed in TRXU -DD-23-026 and
assayed 65.00 g/t Au and 344.39 g/t Ag over 4.57 m within the 75-85 structure (Figures 1 and 3).
Figure 1: Photos of visible gold in TRXU-DD-23-026
(field of view 1 cm diameter with hand lens)
• The 75-85 domain consists of a discrete, north -south striking moderate to steeply west -dipping
structure in the footwall of the T4 that was historically mined prior to the discovery of the T2. See
Figure 3 for domain geometry and relationships.
• The T1 domain consists of Tintic Quartzite -hosted disseminated mineralization interpreted as a
lower-grade halo to the T2. TRXU -DD-23-030 assayed 18.91 g/t Au and 300.00 g/t Ag over 0.91
m.
• These drilling results will provide valuable infill data to impr ove our understanding and the
confidence level of the mineralized zones defined in the Trixie MRE and to support a future mineral
resource update.
• The exploration results will indicate the extent of the mineralized structures and will assist in the
direction of future underground exploration development.
CHIP SAMPLE RESULTS SUMMARY
• Chip samples were collected from the T2 structure and T4 stockwork on the 625 level (See Figures
4 and 5)
• Sampling on the 625 level focussed on development to the north towards the Trixie fault and the
756 vein.
o Assays in this area include 30.17 g/t Au and 62.76 g/t Ag over 1.34 m in CH01527.
• The sampling and drilling results provide support that our target areas to the north of Trixie and to
the south down plunge of the T2 are mineralized and warrant further follow up drilling and sampling.
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• These sampling results will provide valuable data to improve our understanding and the confidence
level of the mineralized zones defined in the area of the Trixie MRE and support a future mineral
resource estimate update.
Face Sampling Methodology
As most structures at Trixie are steeply dipping to the east or west, current sampling procedures are
designed to sample the structure. Chip samples are collected and do not exceed 1.0 m (3 ft.) in length.
The face is washed for safety, and for better identification of mineralization, alteration and structures. The
hanging wall and footwall of the structures are marked up on the face and back, samples intervals are
marked up and follow lithological contacts.
Samples are collected in feet and assays are repo rted in grams per tonne and troy ounce per short ton
gold and silver. Conversions to metric and imperial measurements are rounded to two decimal places.
About Trixie
The Trixie test mine is one of several gold and base metal targets within the larger Tintic Project consisting
of >17,000 acres of patented mining claims and mineral leases within the historic East Tintic Mining District
of Central Utah, U.S.A. The T2 and T4 structures at Trixie show multi-ounce gold grades associated with
high sulphidation epithermal mineralization, structurally controlled and hosted within quartzites. The T2
structure mineralization consists of native Au, and rare Au-Ag – rich telluride minerals with quartz. The T4
is a mineralized stockwork zone is located in the hanging wall of the T2 and is comprised of Au -Ag rich
mineralization in host rock quartzite with quartz-barite-sulphosalt stockwork veining. Mineralization reports
consistent multi-ounce gold grades along the entire strike length.
A 3D model and virtual site tour of Trixie and the wider Tintic Project is accessible on the Company's VRIFY
page at: https://vrify.com/decks/12801.
Information relating to the Tintic Project and the Trixie MRE is supported by the technical report titled " NI
43-101 Technical Report, Initial Mineral Resource Estimate for the Trixie Deposit, Tintic Project, Utah,
United States of America", dated January 27, 2023 (with an effective date of January 10, 2023) prepared
for the Company by independent representatives of Micon International Limited (the " Tintic Technical
Report"). Reference should be made to the full text of the Tintic Technical Report, which was prepared in
accordance with National Instrument 43-101 – Standards of Disclosure for Mineral Projects ("NI 43-101")
and is available electronically on SEDAR ( www.sedar.com) and on EDGAR ( www.sec.gov) under Osisko
Development's issuer profile and on the Company's website at www.osiskodev.com.
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Figure 2: Trixie Project Area
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Figure 3: Trixie Cross Section Looking North
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Figure 4: Trixie Long Section
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Figure 5: Trixie Long Section Sample Highlights
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Table 1: Drilling Length Weighted Assay Composites at Trixie
METRIC IMPERIAL
Hole ID Depth
from (m)
Depth to
(m)
Length
(m) Au (g/t) Ag (g/t) Depth
from (ft.)
Depth to
(ft.)
Length
(ft.) Au (oz/t) Ag (oz/t) Comments
TRXU-DD-23-004 No significant assays Exploration + infill
TRXU-DD-23-021 No significant assays Exploration + infill
TRXU-DD-23-022 61.72 63.09 1.37 5.77 64.43 202.50 207.00 4.50 0.17 1.88 Infill -75-85
TRXU-DD-23-023 12.19 13.11 0.91 0.62 84.13 40.00 43.00 3.00 0.02 2.45 Infill T4
TRXU-DD-23-023 45.11 46.63 1.52 1.77 176.00 148.00 153.00 5.00 0.05 5.13 Infill -75-85
TRXU-DD-23-023 48.16 49.38 1.22 4.75 34.69 158.00 162.00 4.00 0.14 1.01 Infill -75-85
TRXU-DD-23-024 41.61 43.28 1.68 4.98 60.98 136.50 142.00 5.50 0.15 1.78 Infill -75-85
TRXU-DD-23-024 46.48 47.85 1.37 2.70 168.00 152.50 157.00 4.50 0.08 4.90 Infill -75-85
TRXU-DD-23-024 59.74 60.96 1.22 3.14 62.19 196.00 200.00 4.00 0.09 1.81 Infill -75-85
TRXU-DD-23-025 19.81 20.42 0.61 0.36 85.85 65.00 67.00 2.00 0.01 2.50 Exploration
TRXU-DD-23-025 75.29 76.81 1.52 3.10 5.14 247.00 252.00 5.00 0.09 0.15 Infill T1
TRXU-DD-23-025 143.71 144.93 1.22 0.40 100.00 471.50 475.50 4.00 0.01 2.92 Exploration
TRXU-DD-23-026 45.72 50.29 4.57 65.00 344.39 150.00 165.00 15.00 1.90 10.04 Infill 75-85
TRXU-DD-23-027 66.90 68.12 1.22 2.22 25.77 219.50 223.50 4.00 0.06 0.75 Exploration
TRXU-DD-23-027 74.37 79.71 5.33 5.09 132.85 244.00 261.50 17.50 0.15 3.87 Exploration
TRXU-DD-23-028 124.82 129.84 5.03 0.87 190.82 409.50 426.00 16.50 0.03 5.57 Infill T1
TRXU-DD-23-028 155.75 156.67 0.91 0.02 200.00 511.00 514.00 3.00 0.00 5.83 Exploration
TRXU-DD-23-029 Hole abandoned
TRXU-DD-23-030 57.30 58.37 1.07 15.91 368.00 188.00 191.50 3.50 0.46 10.73 Exploration
TRXU-DD-23-030 94.49 95.40 0.91 18.91 300.00 310.00 313.00 3.00 0.55 8.75 Exploration
TRXU-DD-23-032 No significant assays Infill T4
TRXU-DD-23-033 42.98 44.20 1.22 19.01 124.00 141.00 145.00 4.00 0.55 3.62 Infill 75-85
TRXU-DD-23-034 No significant assays Exploration + Infill