2015 Exploration Program The exploration program plan at KSM for 2015 was designed to improve the understanding of block cave targets and support engineering/environmental aspects of development scenarios. The overall objective is to enhance project economics by finding the best 2.3 billion tonnes - the mineable material with the highest margins which is the optimum resource size as determined by scoping studies. The objectives for 2015 were: Drilling at Deep Kerr to expand both the length and width of block cave shapes that confine the current resource estimate. Geological projections of the mineralized zone indicate that the block cave shapes are limited by drill data. Extending the footprint of the block cave shapes could increase the potential mining rate for this higher grade material, thereby generating a significant economic benefit to the project. This work will evaluate the performance of the inferred resource block model and permit projections of drilling required to advance the Deep Kerr zone to reserves. Drilling the plunge projection of the Mitchell high-grade zone to test development scenarios that include exploitation of a larger part of Mitchell as a block cave mine. These holes will also provide additional information for the Lower Mitchell block cave shape included in the 2012 Preliminary Feasibility Study. Complete the surface evaluation of sources for toxic metals that may impact infrastructure planning, and define additional potential quarry sites for construction. A high-resolution airborne magnetic survey will also enhance the sub-surface geological model and contribute to exploration targeting and infrastructure area condemnation. The intrusive complex at KSM demonstrates many features characteristic of giant, diorite or monzonite hosted Au-Cu porphyry systems, such as Grasberg, Oyu Tolgoi, Bingham and Pebble. These systems develop at tectonic boundaries where buoyant, hydrated magmas are forced to shallow depths up deep penetrating faults. Near the surface, the metal rich hydrothermal fluids encounter drastic temperature and pressure drops which result in precipitation of metals in an upward and outwardly zoned pattern that characterizes a porphyry system. Dating of the intrusions indicates an age of approximately 190,000,000 years, much older than most known porphyry systems. Subsequent tectonic events have modified the original geologic positioning so that mineral assemblages characteristic of deeper parts of a porphyry system are now at higher levels. For example, at the southern end of Kerr, potassic altered diorite with magnetite veins and high Au-Cu grades, typical of the roots of porphyry systems, are found at the surface near an elevation of about 1,600m. At the northern end, phyllic altered diorite cut by veins with advanced argillic assemblages, which form at much shallower depths, have been intersected at elevations less than 0m. The modified geometry of the porphyry systems at KSM has significant exploration implications, as higher grade deep core zones may occur at exploitable depths. Drill locations for the 2015 program are highlighted in the geology map below. A plan of the airborne magnetic survey (total field) alongside the current geology model is shown at the end of this year s summary. A compilation of exploration targets outside of the resource areas with significant mineralized drilled intercepts is also shown.
Mitchell In order to drill test the deep projection of the central zone and maintain orientations as close as possible at right angles to the interpreted mineralization trend, the holes were started well above and outside of the Mitchell Deposit reserve (see cross sections below). Directional drilling techniques were used down the hole to steer the holes to the target areas. The first two holes in this year's program confirmed continuity of mineralization in the panel above the Mitchell Thrust Fault (MTF) which hosts disseminated and veinlet chalcopyrite in magnetite skarn-style altered sediments and volcanics, a distal component of the Mitchell porphyry system. Intersects up to 192 meters wide grading 0.34% copper and 0.14 g/t gold support revisions of models that will enable conversion of waste to ore in Mitchell open pit scenarios which are planned to precede underground block caving. Below the Mitchell Thrust Fault, where the Mitchell reserves and resources are located, the holes encountered identical sections of altered intrusive rocks that are recognized as host to parts of the Mitchell Deposit. The intrusion is pervasively hydrothermally altered and contains abundant stock work quartz veins. Alteration increases systematically down hole, progressing through intense quartz-sericitepyrite and into chlorite-magnetite-orthoclase alteration. The intervals encountered in holes M-15-130 and 131 pass through several phases of the Mitchell intrusive system, some of which contain gold and copper grades above the Mitchell Deposit average. Variable but mostly lower grades were encountered in a brecciated zone with abundant anhydrite, similar to the Bornite Breccia intersected several hundred meters higher, but without bornite. This was intersected from 1232.3-1510 in M-15-130, 1357.5-1453.4 in M-15-131, and 1214.5-1353.6 in M-15-131A. The geometry is consistent with the moderately northwest dipping orientation of the bornite breccia, however copper and gold grades tend to be higher along the up-dip contact of the zone. This structure is interpreted as a late feature that controlled flow of hydrothermal fluids with an advanced argillic chemistry characteristic of the late stages of porphyry evolution. Bornite was confined mostly to shallower portions of the structure where cooler conditions favoured precipitation. Hole M-15-131A intersected a distinct medium to coarse grained, sub-porphyritic monzodiorite from 1376.8 to 1655m with grades below the Mitchell average. This intrusion is interpreted to be a later phase, with primary k-feldspar phenocrysts, an alteration mineral assemblage dominated by secondary k-feldspar, magnetite, epidote and traces of actinolite, and a poor development of stockwork quartz veins and sulfides. This low grade intrusion has been intersected in several other holes, but over much narrower widths suggesting the thickness in this hole reflects a local thickening or flexure and does not reflect the true volume of displaced higher grade. All three holes confirmed the presence of a roughly 50m thick, banded, mylonitic shear zone that may offset the base of the Mitchell deposit (Basal Shear Zone, BSF), seen previously only in hole M-08-062. The zone dips to the northwest and appears to parallel the MTF. The following table summarizes the composited assay results for significant drill hole intersections from Mitchell zone drilling in 2015. In drill hole M-15-130, the Mitchell Thrust Fault is located at 601 meters and in M-15-131 it is at 691 meters. M-15-131A was wedged off of M-15-131 at 622.6m.
Hole ID M-15-130 M-15-131 M-15-131A Total Depth (m) From (m) To (m) Thickness (m) Au g/t (uncapped) Cu % (uncapped) Ag g/t (uncapped) 1581 334 441.55 107.55 0.11 0.39 1.7 601.75 638.4 36.65 0.65 0.05 7.3 1034.4 1076.4 42 0.59 0.12 5.8 1207.4 1381.8 174.4 0.55 0.28 3.3 Incl. 1217.4 1296.3 78.9 0.73 0.40 4.8 1674 253 444.5 191.5 0.14 0.34 1.6 1190.5 1357.5 167 0.81 0.25 5.0 Incl. 1248.5 1357.5 109 0.96 0.32 6.3 1449.5 1505 55.5 0.42 0.24 3.5 1760.5 1043.5 1303.5 260 0.53 0.18 4.4 Incl. 1043.5 1070.5 27 0.80 0.17 9.8 Incl. 1108.5 1214.5 106 0.66 0.18 4.4 Incl. 1250.5 1299.9 49.4 0.48 0.29 3.9 1379.5 1579.5 200 0.43 0.16 2.9 Incl. 1433.5 1503.5 70 0.51 0.19 3.0 Photographs of polished drill core samples representative of mineralization styles encountered in 2015 are shown below. Width of the core samples (vertical axis) is approximately 2.5cm. Cross sections and a level plan follow. HOLE-ID DEPTH Au g/t Cu % Mo % Ag g/t As ppm Pb ppm Zn ppm M-15-130 1037 0.32 0.19 0.0482 3 38 22 30 Mitchell diorite porphyry, phyllic altered with D veins and Mo, no A or B veins with cp
HOLE-ID DEPTH Au g/t Cu % Mo % Ag g/t As ppm Pb ppm Zn ppm M-15-130 1248.5 0.90 0.45 0.0036 4 3 10 23 Mitchell Breccia zone, altered P1B with anhy, py, cp but no bornite, average grade at this depth HOLE-ID DEPTH Au g/t Cu % Mo % Ag g/t As ppm Pb ppm Zn ppm M-15-131A 1583.5 0.46 0.13 0.0008 1.8 5 6 50 Mitchell monzodiorite porphyry, later, coarser grained, calcic-potassic altered, A+B veins, low grade, may indicate lower limits of mineralization HOLE-ID DEPTH Au g/t Cu % Mo % Ag g/t As ppm Pb ppm Zn ppm M-15-130 1561.3 0.06 0.05 0.0002 1 8 47 38 Mitchell Basal Shear Zone (BSZ): mylonitized rock, phyllic altered, low to nil grade
Deep Kerr The Kerr deposit is centered on a north-south trending, steep westerly dipping, tabular intrusive complex that drilling demonstrates has a horizontal extent of 2,400 meters and vertical extent of at least 2,200 meters. The complex includes an east and west limb that may coalesce near the current surface. The west limb is up to 500 meters thick, and the east limb up to 300 meters thick. There are several distinct intrusive phases, the earliest of which are fine grained diorites with 5% to 60% quartz-sulfide vein stockworks and these appear to contribute the majority of metals. Later phases envelope and sometimes invade the earlier phase, and are characterized by coarser textures, less veining, and lower metal contents. The intrusions are hosted by an Early Jurassic sequence of rhythmically bedded siltstones, sandstones, conglomerates, and debris flows that have been altered adjacent to the intrusions but generally contain marginal metal grades. The holes in this year's Deep Kerr program were collared well outside the mineral deposit in order to achieve the deep intersections that test the dip extension. Drill holes were designed to intercept the mineralized target at right angles to the strike of the zone and downhole directional drilling tools were used to steer the holes to target areas. These locations better defined the western limits of the mineralized system, and demonstrate that a north-south trending normal fault places unaltered finegrained sedimentary rock against the outer weakly mineralized parts of the mineral system. As the drill holes advance to the east, alteration and mineralization increase as a series of potassically-altered intrusions are encountered. Drill hole K-15-49 passed out of the intensely altered and mineralized zone into younger intrusions with lower concentrations of gold and copper. The drill hole was not extended into the eastern high-grade zone encountered in previous shallower drilling because projected depths would have been prohibitive. This eastern zone remains a high potential target. The holes drilled this year confirmed a high degree of continuity of mineralization over very considerable distances. Holes K-15-49 and K-15-49A confirmed down-dip extension of the strong mineralization in the west limb intersected by hole K-14-45, an oblique hole that cut 503m grading 0.40g/t Au and 0.67% Cu. This mineralization occurs mainly in the PAND1 diorite, the early mineralizing phase of the Kerr intrusive complex. It is finer grained, exhibits a high chalcopyrite to pyrite ratio, has remnants of secondary potassic alteration now mostly overprinted by retrograde chloritic alteration, and a mostly intact stockwork of quartz-sulfide veinlets. Portions of the PAND1 intrusion are overprinted by phyllic alteration characterized by sericitization of mafic minerals, higher pyrite content, and higher Au and Cu grades. The later PAND2 diorite is coarser grained, with very few intact quartz veinlets, and a lower metal content. Wall rock sediments are mineralized adjacent to the intrusions, but generally lower grade. Currently the lithology model lumps moderately mineralized PAND2 dykes, breccias, and sediment intervals in the hanging wall of the PAND1 body into the IBX domain, however definition drilling is expected to enable resolution of this into finer components. A few meter-scale, late quartzcarbonate-sulfide veins with strong Au and elevated Cu, Pb, Zn, and As levels cut the intrusions and wall rocks, and indicate penetration of late advanced argillic fluids along steep fractures. Holes K-15-50 and K-15-50A tested the west limb 200m on strike to the south of K-15-49 and K-15-49A. Continuity of the mineralized PAND1 intrusion was confirmed, however on this section gold and copper grades are lower. This is attributed to a higher proportion of lower grade PAND2 intrusion, as well as weaker overprinting phyllic alteration. Hole K-15-49B tested the west limb 200m north of K-15-49, and lower grades were also found to be due to a lower proportion of the PAND1 intrusion.
The following table summarizes the drill hole intersections for 2015. Hole ID Total Depth (m) From (m) To (m) Thickness (m) Au g/t (uncapped) Cu % (uncapped) Ag g/t (uncapped) K-15-49 1755.4 1272 1755.4 483.4 0.43 0.56 2.9 Incl. 1466.4 1716.4 250 0.49 0.70 3.7 1710.4 1178.3 1244.15 65.85 0.41 0.36 2.1 K-15-49A 1304.4 1644.2 339.8 0.53 0.60 3.1 Incl. 1358.2 1555 196.8 0.69 0.72 4.0 1731.4 963.5 1020.1 56.6 0.67 0.12 7.0 K-15-49B 1379 1461.6 82.6 0.43 0.55 3.3 1534.5 1668.85 134.4 0.20 0.45 1.4 Incl. 1574 1627.2 53.2 0.31 0.56 1.7 1764.4 1430.4 1764.4 334 0.41 0.30 2.4 K-15-50 Incl. 1433 1598.4 165.4 0.56 0.27 3.1 Incl. 1659.4 1713.8 54.4 0.29 0.41 2.0 1718.5 1246.5 1369.5 123 0.44 0.30 2.1 K-15-50A 1452.5 1704.5 252 0.38 0.31 2.2 Incl. 1559.3 1620.5 61.2 0.63 0.42 3.1 Photographs of polished drill core samples representative of mineralization styles encountered in 2015 are shown below. Width of the core samples (vertical axis) is approximately 2.5cm. Cross sections and a level plan follow. HOLE-ID DEPTH Au g/t Cu % Mo % Ag g/t As ppm Pb ppm Zn ppm K-15-49 1476.5 0.43 0.84 0.0006 3 4 2 49 Kerr PAND1 diorite intrusion: early, fine grained, potassic altered diorite with mostly intact stockwork qtz-cp-py veins
HOLE-ID DEPTH Au g/t Cu % Mo % Ag g/t As ppm Pb ppm Zn ppm K-15-49B 1605 0.39 1.08 0.0001 2 16 17 70 Kerr PAND1 diorite intrusion: early, fine grained, potassic altered diorite with mostly intact stockwork qtz-cp-py veins HOLE-ID DEPTH Au g/t Cu % Mo % Ag g/t As ppm Pb ppm Zn ppm K-15-49 1616.9 0.85 1.16 0.0026 8 21 51 44 Kerr PAND1 diorite intrusion(?): intense phyllic overprint with abundant py, addition of Au and Cu HOLE-ID DEPTH Au g/t Cu % Mo % Ag g/t As ppm Pb ppm Zn ppm K-15-49 1394.9 0.33 0.04 0.0001 0.6 1 1 10 Kerr PAND2 diorite intrusion: later, slightly coarser grained, potassic altered diorite with no stockwork qtz-cp-py veins, a few orphaned vein fragments assimilated from PAND1
HOLE-ID DEPTH Au g/t Cu % Mo % Ag g/t As ppm Pb ppm Zn ppm K-15-49B 1672.5 0.07 0.15 0.0020 0.9 33 13 113 Kerr PAND2 diorite: later, coarser grained, potassic altered, no stockwork veins, a few orphaned vein fragments assimilated from PAND1 HOLE-ID DEPTH Au g/t Cu % Mo % Ag g/t As ppm Pb ppm Zn ppm K-15-50 1538.9 0.17 0.22 0.0019 1.1 9 6 56 Kerr PAND2 diorite: later, coarser grained, potassic altered, stockwork veins, a few orphaned vein fragments assimilated from PAND1 HOLE-ID DEPTH Au g/t Cu % Mo % Ag g/t As ppm Pb ppm Zn ppm K-15-49 1721.5 0.18 0.42 0.0033 1 5 4 46 Kerr Sediments: chloritic-hornfels altered wall rocks, mostly fracture or breccia controlled and disseminated, low-grade mineralization