The 3 Aces Property, in the southeast corner of Yukon Territory, is sited along the edge of the ancient North American continental shelf.  This large land holding is on the eastern margin of the Selwyn Basin, a long, narrow belt that extends across much of the south-eastern and central portions of the Yukon. The sedimentary rock record preserved in the Selwyn Basin chronicles the progressive infilling of Proterozoic through Paleozoic rift basins that formed along the margin of Ancient North America.  These sedimentary rocks were deformed and metamorphosed during Cretaceous time by the intrusion of numerous granitic bodies.

Hyland Group sedimentary rocks underlay the 3 Aces claims, these rocks representing the bottom of the Selwyn Basin near the terrain boundary with the older North American continent.  These sedimentary rocks consist of medium to coarse grained clastic beds intercalated with shale.  Deformation at this older continental margin has produced a folded package of rocks with intense faulting at the contact between shale and sandstones/conglomerates. Gold-bearing quartz veins fill these faults at the contacts between sedimentary units.

An orogenic gold model best fits the occurrences at 3 Aces, where contact metamorphic features and metal zonation are absent.  Massive quartz veins, hosted in structural zones at contacts, commonly contain exceptionally high gold grades (often exceeding 1,000 g/t gold). The coarser-grained sedimentary units are frequently quartz-flooded, forming haloes around the massive veins with lower grade gold mineralization (ranging from 0.5 g/t to about 6.0 g/t gold).  Veins hosted in the fine-grained sedimentary rocks are narrow but often contain high grade gold.  These sulfide-poor quartz veins and surrounding quartz flooding contain gold, arsenopyrite and pyrite with trace amounts of pyrrhotite, chalcopyrite and galena.

The scientific and technical information in respect of the KSM Project herein was derived from the technical Report entitled KSM (Kerr – Sulphurets – Mitchell) Prefeasibility Study and Preliminary Economic Assessment dated effective August 8, 2022. This information was prepared by leading consulting firms and their Qualified Persons (as defined in NI 43-101), all of who are independent of Seabridge and are listed below along with their areas of responsibility:
(i) Tetra Tech, Inc. under the direction of Hassan Ghaffari P.Eng (surface infrastructure, capital estimate and financial analysis), John Huang P.Eng. (metallurgical testing review, permanent water treatment, mineral process design and operating cost estimation for process, general and administrative (“G&A”) and site services, and overall report preparation)
(ii) Wood Canada Limited, under the direction of Henry Kim P.Geo. (Mineral Resources)
(iii) Moose Mountain Technical Services under the direction of Jim Gray P.Eng. (open pit Mineral Reserves, open pit mining operations, mine capital and mine operating costs, MTT and rail ore conveyance design, tunnel capital costs)
(iv) N. Brazier Associates Inc. under the direction of W.N. Brazier P.Eng. (Electrical power supply, energy recovery plants)
(v) ERM Consultants Canada Ltd. under the direction of Rolf Schmitt P.Geo. (environment and permitting)
(vi) Klohn Crippen Berger Ltd. under the direction of David Willms P.Eng (design of surface water diversions, diversion tunnels, tailing management facility, water treatment dam and RSF and tunnel geotechnical)
(vii) BGC Engineering Inc. under the direction of Derek Kinakin P.Geo., P.L.Eng., P.G. (rock mechanics, geohazards and mining pit slopes)
(viii) WSP Golder Inc., under the direction of Ross Hammett P.Eng (Block Cave mining)