Osisko Development Provides Exploration Update at Tintic Project
NYSE | TSXV: ODV NEWS RELEASE
Page 1 of 10
OSISKO DEVELOPMENT PROVIDES EXPLORATION UPDATE AT TINTIC PROJECT
Montreal, Québec, August 7, 202 4 – Osisko Development Corp. (NYSE: ODV, TSXV: ODV)
("Osisko Development" or the "Company") is pleased to provide an update on exploration activities
at its 100%-owned Tintic Project ("Tintic" or the " Tintic Project"), located in the historic East Tintic
Mining District in central Utah, U.S.A. This includes results of recently completed surface and
underground diamond drilling targeting potential copper -gold-molybdenum porphyry centers ,
underground chip sampling at the Trixie test mine ("Trixie"), and ongoing target generation work.
Chris Lodder, President, stated, "Early results from our systematic exploration approach are yielding
valuable information in assisting with vectoring toward potential mineralized porphyry sources and large
undiscovered polymetallic carbonate replacement deposits. We are seeing encouraging porphyry style
mineralization in drill holes that are providing us with better understanding of the geometry, ore controls
and zoning of mineralization at East Tintic. With this knowledge, we are well positioned to continue to
vector towards more copper-rich areas believed to be the source of known mineralization at Tintic. Utah
was most recently ranked by the Fraser Institute as the top mining jurisdiction globally, and we are
excited at the future prospect of building on our presence there."
BIG HILL PORPHYRY TARGET DRILLING
• Drilling Results. Two surface diamond drill holes, BH -DD-24-001 and BH -DD-24-002, have
been completed at the Big Hill target Area in early May 2024 (see Figure 2).
o The first drill hole was completed to a depth of 1,297 meters ("m") (4,257 feet ("ft"))
when it transitioned out of the prospective alteration zone. The second drill hole was
repositioned at a modified angle and completed to a depth of 1,623 m (5,324 ft).
o Both drill holes intersected porphyry systems defined by at least three late -mineral
monzonite porphyritic intrusive phases and an intrusion breccia over a vertical depth of
approximately 1,500 m (see Figure 3).
o Although anomalous copper and molybdenum mineralization was encountered, including
low visible presence of chalcopyrite, tennantite, and molybdenite , this was primarily
localized along structures, and hydrothermal breccias, and the transition from
calcareous rocks into quartzites. No significant intercepts of copper, gold or molybdenum
were observed. The porphyries encountered to date are considered to lack evidence for
the major fluid paths required to be the source of mineralization in the Tintic District.
o Results to date have shown that t he porphyries and intrusion breccia display potassic
alteration with anhydrite and pyrite veinlets, which have undergone variable retrograde
alteration to illite -chlorite and have been overprinted by pyrophyllite, dickite, and
kaolinite along fault zones. This combination of intrusive rocks and alteration are clear
evidence of the presence of a porphyry style mineralization at Big Hill . However, they
are weakly mineralized , late inter -mineral phases that often post -date the better
mineralized early-porphyry intrusive phases in well known porphyry deposits.
• Big Hill West Target. The results of the recent and historical drill holes suggest that the early
and potentially better mineralized intrusive phase could be in an untested area immediately west
and southwest of the area drilled at Big Hill (see Figure 3).
o Early porphyry intrusions, with more intense veinlets and alteration, are thought to be
required to explain the metal inventory of the Tintic District.
Page 2 of 10
o Drill core to date has shown that carbonate rocks in the intrusion breccia are marbleized
and, in places, altered to retrograde skarn. Some discrete intervals comprise a finer -
grained monzonite porphyry which is cut by porphyry -style quartz and magnetite
veinlets, some containing pyrite an d molybdenite with clear B-type affinity (see Figure
1). These inter-mineral intercepts, only approximated in Figure 3, are considered as
blocks or screens 'floating' in the late -mineral phases, indicating that there are e arly
and likely better mineralized inter-mineral intrusive phases to be found at Big Hill.
Figure 1: Core photos from Big Hill drill holes showing texture of intrusive rocks and
associated alteration, veinlets, and breccia-clasts characteristic of porphyries.
• The potassically altered late-mineral porphyries are chilled against the quartz -veined porphyry
intervals, defining them as inter-mineral in timing. These inter-mineral intercepts (approximated
in Figure 3) are considered as blocks or screens 'floating' in the late -mineral phases. A similar
quartz-veined porphyry is more abundant in the core from BPC-08-002 drilled by Anglo American
at Big Hill (see Figure 2) in 2008. This drillhole also included appreciable thicknesses of the same
intrusion breccia.
Page 3 of 10
Figure 2: Tintic Project plan map showing the Big Hill, Zuma, and Lower Quartzite CRD
targets.
Page 4 of 10
Figure 3: Big Hill geological section, presenting geology logged in drill holes BH-DD-24-
001 and BH-DD-24-002 and the Big Hill West target.
TRIXIE WEST PORPHYRY TARGET DRILLING
• One diamond drill hole, TRXU-DD-23-073, was completed from underground testing porphyry-
style mineralization down plunge of the mineralized structures below Trixie (see Figure 2).
o The drill hole was completed to a depth of 759.6 m (2,492 ft) when it crossed the Eureka
Lily Fault to the east and out of the prospective alteration zone.
o After collaring into the lower portion of the Ophir shale the drillhole remained in the
Tintic Quartzite formation without intersecting porphyritic intrusions. Favorable
geochemical and alteration mineral indicators were observed in the upper sections of
the drillhole. However, at approximately 390 m (1,278 ft) downhole, the regional scale
Eureka Lilly fault was crossed, beyond which these indicators significantly diminished.
o These results suggest that the western hanging wall block of the Eureka Lilly fault is
more conducive for porphyry-style mineralization. Therefore, future drilling efforts will
be more effective from the Zuma area, located west of Trixie (see Figure 2).
• Anomalous mineralization was encountered in the drill hole, primarily attributed to localized
small structures in the Tintic Quartzite and appear to be of a similar mineralization style as found
at the main Trixie deposit. However, no significant intercept s of gold, copper or molybdenum
were encountered in TRX-DD-23-073.
HIGH-POTENTIAL PORPHYRY AND CRD TARGETS
The Zuma Target
• The Zuma area is considered a good porphyry target that merits initial drill testing and may
represent one of the causative porphyry centres of the East Tintic district (see Figures 2 and 4).
Page 5 of 10
• It is defined by overlapping geochemical and geophysical anomalies : the confluence of several
regional scale structures linked to known high -sulfidation mineralization, the presence of early
quartz veinlets on surface, and indications of multiple phases of magmatism (Figure 2).
• Drill testing of the anomalies identified at Zuma is considered a high-priority porphyry target.
Lower Quartzite CRD Target
• Based on the compilation of geological, drilling, and historical data , a potential large scale
carbonate replacement deposit ("CRD") may be located below the footwall of the East Tintic
thrust fault (see Figure 4).
• A recommended drill target follows downdip extensions of known mineralization at Burgin, along
the traces of the NE faults below where they intersect the west dipping thrust fault that defines
the base of the quartzite. Of note, historic production and most known metal inventory in the
Burgin area represents close to 45% of the total mineralization discovered and mined in the
East Tintic district. Meaning , these ore deposits are typically larger than those in veins and
narrow mantos at the top of the quartzite (see Figure 4).
Figure 4: Interpreted West -East cross section, looking North, from the Main (West
Camp, Ivanhoe Electric 's land) passing east into the central valley zone and the East
Camp of Tintic (ODV's land).
• CRD mineralization mined in the East Tintic district, except for the Burgin deposit, has all been
localized at the upper contact or close to the upper contact of the Tintic Quartzite and the
calcareous strata of the Ophir formation ( see Figure 4 ), structurally confined along the
intersection of NE trending faults (see Figure 2).
• Figure 4 shows main lithological units, high angle faults and folds, a main low angle thrust fault
putting in contact older quartzites over younger calcareous rocks in East Tintic. It also includes
an approximate location of known main ore bodies, potential location of the proposed causative
porphyry center of Zuma (drill target) and a potential connection of proximal Cu-Au CRD-Skarn
mineralization below the thrust fault -plain starting at the limits of the causative porphyry and
changing toward the east into Zn -Pb-Ag-Mn distal mineralization at Burgin. The proposed CRD
drill hole is located between Burgin and Trixie.
Page 6 of 10
TRIXIE UNDERGROUND CHIP SAMPLE ASSAY HIGHLIGHTS
Chip samples were collected from new development areas in the walls of an exploration crosscut to
explore along the Wild Cat, T2 and T4 domains of the Trixie deposit on the 625 Level (see Figure 5).
Assay highlights include underground chip samples from four new development faces. All four faces had
samples with greater than 1.0 gram per tonne ("g/t") gold ("Au") or greater than 50.0 g/t silver ("Ag")
values (see Table 1 ). The remaining chip samples returned no significant assays. Selected assay
highlights include:
• 11.07 g/t Au and 25.45 g/t Ag over 6.10 m in CH01716 (0.32 ounce per ton ("oz/t") Au and
0.74 oz/t Ag over 20 ft) including
o 90.20 g/t Au and 226.33 g/t Ag over 0.30 m (2.63 oz/t Au and 6.60 oz/t Ag over 1 ft)
• 9.13 g/t Au and 28.69 g/t Ag over 6.71 m in CH01717 (0.27 oz/t Au and 0.84 oz/t Ag over 22
ft) including
o 21.77 g/t Au and 52.31 g/t Ag over 1.52 m (0.63 oz/t Au and 1.53 oz/t Ag over 5 ft)
Figure 5: Trixie Cross Section with Chip Highlights
Page 7 of 10
Table 1: Chip Sample Length Weighted Assay Composites at Trixie
Site 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)
CH01714 1.52 2.44 0.91 1.23 18.07 5.00 8.00 3.00 0.04 0.53
CH01714 4.11 4.57 0.46 2.30 111.42 13.50 15.00 1.50 0.07 3.25
CH01714 7.01 7.62 0.61 1.10 8.09 23.00 25.00 2.00 0.03 0.24
CH01715 0.91 2.13 1.22 5.83 15.56 3.00 7.00 4.00 0.17 0.45
CH01715 16.15 16.46 0.30 53.07 162.32 53.00 54.00 1.00 1.55 4.73
CH01716 1.52 4.57 3.05 2.97 9.62 5.00 15.00 10.00 0.09 0.28
CH01716 Including 1.52 3.05 1.52 3.09 9.15 5.00 10.00 5.00 0.09 0.27
CH01716 and 3.05 4.57 1.52 2.85 10.08 10.00 15.00 5.00 0.08 0.29
CH01716 7.62 13.72 6.10 11.07 25.45 25.00 45.00 20.00 0.32 0.74
CH01716 Including 7.62 8.38 0.76 25.09 38.60 25.00 27.50 2.50 0.73 1.13
CH01716 and 8.38 9.45 1.07 4.53 7.75 27.50 31.00 3.50 0.13 0.23
CH01716 and 9.45 9.75 0.30 90.20 226.33 31.00 32.00 1.00 2.63 6.60
CH01716 and 9.75 10.67 0.91 6.27 19.03 32.00 35.00 3.00 0.18 0.55
CH01716 and 10.67 12.19 1.52 1.61 5.45 35.00 40.00 5.00 0.05 0.16
CH01716 and 12.19 13.72 1.52 5.14 14.95 40.00 45.00 5.00 0.15 0.44
CH01716 15.24 16.76 1.52 1.17 11.35 50.00 55.00 5.00 0.03 0.33
CH01717 0.00 1.52 1.52 3.46 0.00 0.00 5.00 5.00 0.10 0.00
CH01717 3.05 4.57 1.52 5.38 13.61 10.00 15.00 5.00 0.16 0.40
CH01717 10.06 16.76 6.71 9.13 28.69 33.00 55.00 22.00 0.27 0.84
CH01717 Including 10.06 10.21 0.15 23.04 63.32 33.00 33.50 0.50 0.67 1.85
CH01717 and 10.21 10.67 0.46 2.02 14.12 33.50 35.00 1.50 0.06 0.41
CH01717 and 10.67 12.19 1.52 3.19 18.07 35.00 40.00 5.00 0.09 0.53
CH01717 and 12.19 13.72 1.52 21.77 52.31 40.00 45.00 5.00 0.63 1.53
CH01717 and 13.72 14.94 1.22 8.13 22.22 45.00 49.00 4.00 0.24 0.65
CH01717 and 14.94 15.70 0.76 7.92 32.53 49.00 51.50 2.50 0.23 0.95
CH01717 and 15.70 16.76 1.07 2.64 16.08 51.50 55.00 3.50 0.08 0.47
Page 8 of 10
About Trixie
The Trixie test mine is one of several gold and base metal targets within the larger Tintic Project
consisting of > 20,500 acres of mining claims ( 18,783 acres of patented mining claims and a further
approximately 1,807 acres of unpatented mining claims) within the historic East Tintic Mining District of
Central Utah, U.S.A. The T2 and T4 zones 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 qua rtz. The
T4 is a broad enveloping zone , encompassing multiple discrete quartz -barite stockwork and fissure
veining structures and structural zones developed around and similar to the discrete T2 structure and
is located in the foot wall of the 75-85 zone.
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/15815.
Technical Report
Information relating to the Tintic Project and the current MRE for the Trixie deposit (the " 2024 Trixie
MRE") is supported by the technical report titled " NI 43 -101 Technical Report, Mineral Resource
Estimate for the Trixie Deposit, Tintic Project, Utah, United States of America ", dated April 25, 2024
(with an effective date of March 14, 2024) 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.sedarplus.ca) and on EDGAR ( www.sec.gov) under Osisko Development's issuer profile and on
the Company's website at www.osiskodev.com.
Qualified Persons
The scientific and technical information contained in this news release has been reviewed and approved
by Daniel Downton, P.Geo., Chief Resource Geologist of Osisko Development, and a "qualified person"
within the meaning of NI 43-101.
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 1.5 m (5 ft.) in length.
The face is washed for safety, and for better iden tification 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 reported 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.
Quality Assurance (QA) – Quality Control (QC)
All drill core and exploration samples are dispatched to ALS Geochemistry in Elko, Nevada or Reno,
Nevada for offsite sample preparation and analysis. ALS Geochemistry is ISO/IEC 17025 and ISO 9001
certified. Samples are assigned a unique sample ID. All geological and sampling information is entered
into Datamine Fusion database. Core is sawn in half and half is sampled. Certified standards and blanks
are inserted into all sample dispatches. Samples are collect ed by Old Dominion Transportation and
dispatched to ALS Geochehistry's laboratories in Elko, Nevada or Reno, Nevada. Sample submission
forms accompany the samples, and digital copies are emailed to ALS Geochemistry.
All core sample preparation is completed by ALS Geochemistry , including drying, crushing, and
pulverizing of samples. Analytical assays include gold by 30-gram fire assay with AAS finish , and gold
overlimits by fire assay with gravimetric finish. Screen metallic and hyperspectral analyses are
performed on selected samples. Multielement analysis (including silver) is by four-acid digest with ICP-
AES/ICP-MS finish. The pulps are returned to Osisko Development and coarse rejects are disposed after
90 days. Assays are reported to Osisko Development and then loaded into Datamine Fusion. Quality