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Deposit geology Gold mineralization 1 Geology of the Detour Lake Deposit.

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Presentation on theme: "Deposit geology Gold mineralization 1 Geology of the Detour Lake Deposit."— Presentation transcript:

1 Deposit geology Gold mineralization 1 Geology of the Detour Lake Deposit

2 US$775 reserve pit Sunday Lake Deformation Zone Detour Lake – Deposit geology  Gold mineralization occurs in a vein field extending > 3 km along strike, width of 200-350 m and 1 km below surface 2 400m

3 Lithology and Mineralization CMH SLDZ $775 reserve pit Mafic massive flow Mafic pillow flow Chert Marker Horizon (CMH) Ultramafic rocks and chloritic greenstone Footwall volcanic and sedimentary rocks Main mineralized zones 3

4  SLDZ is a 10-50 m wide sub-vertical high strain corridor  Several sub-parallel, E-W striking high strain zones associated with gold minerali-zation occur in HW of SLDZ 4 (massive mafic flow) DG-07-248 150m 161m Lower Detour Lake Fm Upper Detour Lake Fm Alteration Strain 0.4 g/t 3.6 g/t 0.2 g/t 8.2 g/t (talc-chlorite schist) SLDZ Sunday Lake Deformation Zone

5 Hanging Wall Mafic Volcanics DG-07-128 177.6m 180.9m 183.6m 189.9m 191.2m 194.3m 197.1m 202.0m 207.3m 188.3m Mafic massive flow Mafic pillow flow Alteration Strain 2.0 g/t 0.3 g/t 6.3 g/t 1.5 g/t 0.1 g/t 0.01 g/t 0.03 g/t 0.05 g/t 0.02 g/t 0.04 g/t Stretched vesicles in barren flattened pillow Pyrrhotite and pyrite emplaced along pillow margin and breccia 3.0 g/t Au 5

6 CMH and SLDZ Mineralization CMH, a highly silicified and mylonitized rock, incorporated within SLDZ throughout the deposit Po and Py veinlets in ultramafic rocks in SLDZ DG-09-658 152.4m 152.7m 154.8m 165.3m 170.0m 175.2m 180.4m Alteration Strain 1.5 g/t 0.3 g/t 0.5 g/t 1.2 g/t 0.7 g/t 0.6 g/t 18.6 g/t 3.6 g/t 6

7 Gold Mineralization  E-W striking stockwork of qtz-carb veins developed along sub-parallel high strain zones in HW of SLDZ  Strong biotite alteration 7 31.2 g/t Au 1 cm SLDZ

8 Vein Geometry – 280°/90°  Qtz-carb veins generally strike E-W with steep dips, up to several cm’s thick, contain visible gold and are variably deformed  Qtz-carb stockwork overprinted by auriferous Py- Po-Cpy veins and aggregates, preferentially deposited in low-stress structural sites 8 Average vein orientation 280/90 91.5 g/t Au 2.2 g/t Au

9 Shear Zone Kinematics 9  Structures observed indicate reverse north- over-south kinematics at Detour Lake Steep mineral stretching lineation Asymmetric pressure shadow around plagioclase phenocryst Flat pyrite-pyrrhotite vein Flat extensional qtz vein Boudinaged qtz vein sub-parallel to steep dipping E-W striking foliation

10 10 Ore Plunge $775 Pit Average Foliation: 109/82 Average Vein 289/89 Intersection 33°  283°  Boudins and fold axes of auriferous qtz veins, and qtz vein intersections plunge moderate to W corresponding to ore plunge (orthogonal to stretching lineation) Stretching lineation Leapfrog gold grade shells (grey = 1 g/t, yellow = 3 g/t and orange = 5 g/t) with mined out stopes in brown

11 11 SLDZ Kinematics

12 $575 Pit $450 Pit $575 Pit CategoryTonnes (Mt) Grade cut to 20 g/t Contained Gold Oz (cut) M+I89.91.674,831,000 Inferred35.41.803,025,000 Detour Gold 50,000 m: Dec 2007 – Mineral Resources* * Based on a cut-off grade of 0.64 g/t Au, US$575/oz gold price 12


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