OZ Minerals Limited Mineral Resources Explanatory Notes as at 30 June 2008 TABLE OF CONTENTS 1 MARTABE MINERAL RESOURCES STATEMENT - 30 JUNE 2008 3 2 SEPON COPPER MINERAL RESOURCE STATEMENT - 30 JUNE 2008 8 3 SEPON GOLD MINERAL RESOURCE STATEMENT - 30 JUNE 2008 27 4 PROMINENT HILL MINERAL RESOURCE STATEMENT - 30 JUNE 2008 45 5 CENTURY MINERAL RESOURCES STATEMENT - 30 JUNE 2008 56 6 DUGALD RIVER MINERAL RESOURCE STATEMENT - 30 JUNE 2008 70 7 GOLDEN GROVE MINERAL RESOURCES STATEMENT - 30 JUNE 2008 77 8 ROSEBERY MINERAL RESOURCE STATEMENT - JULY 2008 98 9 AVEBURY MINE AREA RESOURCES - JANUARY 2008 107 10 HIGH LAKE MINERAL RESOURCE STATEMENT - 30 JUNE 2008 113 11 IZOK LAKE MINERAL RESOURCE STATEMENT - 30 JUNE 2008 123 OZ Minerals Limited Mineral Resources Explanatory Notes - 30 June 2008 - FINAL.doc Page 2 of 132 Mineral Resources 2008 Explanatory Notes 1 MARTABE MINERAL RESOURCES STATEMENT - 30 JUNE 2008 1.1 Introduction The Martabe June 2008 Mineral Resource Statement incorporates the gold and silver Mineral Resources at the Martabe Project in North Sumatra Indonesia. Since the previous Mineral Resource Statement in December 2007, remodelling of the Pit 1 (previously reported as Purnama) Mineral Resource has been completed. An infill program in the central part of Pit 1 between 167100N and 167300N was completed in late December 2007. A total of 35 additional holes for 6086m were drilled to infill drill the selected area using 25-meter spaced holes. There have been no changes to the Barani (previously named Pelangi) and Ramba Joring (previously named Baskara) Mineral Resources. 1.2 Results Table 1 Martabe Mineral Resources as at 30 June 2008 Deposit Category Tonnes Grade Contained Metal (kt) Au Ag Au Ag (g/t) (g/t) (koz) (koz) Pit 1 Measured 3,792 2.9 46 354 5,568 Indicated 47,710 1.7 22 2,604 33,513 Inferred 39,650 1.1 13 1,388 17,201 Total 91,152 1.5 19 4,345 56,282 Ramba Inferred 36,557 1.0 4 1,191 5,207 Joring Total 36,557 1.0 4 1,191 5,207 Barani Inferred 10,390 1.1 368 Total 10,390 1.1 368 Martabe Measured 3,792 2.9 354 Summary Indicated 47,710 1.7 2,604 Au ONLY Inferred 86,597 1.1 2,947 Total Mineral Resource 138,099 1.3 5,905 Pit 1 and Measured 3,792 2.9 46 354 5,568 Ramba Indicated 47,710 1.7 22 2,604 33,513 Joring ONLY Inferred 76,207 1.1 9 2,579 22,408 Au and Ag Total Mineral Resource 127,709 1.3 15 5,537 61,489 OZ Minerals Limited Mineral Resources Explanatory Notes - 30 June 2008 - FINAL.doc Page 3 of 132 Mineral Resources 2008 Explanatory Notes Table 2 compares the Pit 1 (Purnama) Mineral Resource at June 2008 Mineral Resources with an estimate of the tonnage and Au grade at December 2007. The Barani and Ramba Joring Mineral Resources remain unchanged. Table 2 Comparison of Pit 1 Mineral Resource at June 2008 with December 2007 Mineral Resource Estimate June 30 2008 Dec 31 2007 Category Tonnes Grade Au (koz) Tonnes Grade Au Au (koz) Change (kt) Au (g/t) (kt) (g/t) Au (koz) Measured 3,792 2.9 354 0 0 0 354 Indicated 47,710 1.7 2,604 48,750 1.8 2,859 -255 Inferred 39,650 1.1 1,388 42,527 1.1 1,512 -124 Total 91,152 1.5 4,34591,277 1.5 4,371 -25 The primary difference between the December 2007 and the June 2008 Pit 1 Mineral Resource is the category classification. In the new model, 4% of the tonnes have now been classified as Measured mainly at the expense of previously Indicated material, while there is also some improvement of previously Inferred material to Indicated category. Tonnages have varied slightly from the previous model largely due to changes in bulk densities, interpretations for mineralisation and oxidation zones, and parent cell sizes used in the block model. 1.3 Competent Person Statement This Mineral Resource Statement has been compiled in accordance with the guidelines defined in the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (The JORC Code, 2004 Edition). The information in this report that relates to Mineral Resources is based on information compiled by the below listed competent persons, who are Members or Fellows of the Australasian Institute of Mining and Metallurgy or the Australian Institute of Geoscientists and has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which they are undertaking to qualify as Competent Persons as defined in the 2004 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. They consent to the inclusion in the report of the matters based on their information in the form and context in which it appears. Deposit Competent Person Barani (previously called Iain Macfarlane, Senior Consultant Resources, Coffey Mining Ltd. Pelangi) Graham Petersen, Geology Manager Martabe, PT Agincourt Minerals Pit 1 (Purnama) and Ingvar Kirchner, Principal Resource Geologist, Coffey Mining Ltd. OZ Minerals Limited Mineral Resources Explanatory Notes - 30 June 2008 - FINAL.doc Page 4 of 132 Mineral Resources 2008 Explanatory Notes Deposit Competent Person Ramba Joring (Baskara) Graham Petersen, Geology Manager Martabe, PT Agincourt Minerals 1.4 Key Points relating to the June 2008 Mineral Resource Estimate 1.4.1 Drilling The Purnama drilling database comprises an additional 6,086m of surface diamond drilling completed as infill drill holes between 167100N and 167300N, since the previous Mineral Resource statement in December 2007. The additional diamond holes are HQ and PQ diamond core drilled with LF70 rigs. 1.4.2 Drilling Quality Assurance All of the diamond drill hole collar locations are surveyed using Total Station once completed. Down hole surveys are completed by Eastman camera with initial measurements at 20 meters from the collar with subsequent measurements at nominal 50m intervals and at the end of the hole. Drill hole locations and orientations were validated by plotting collar pick ups against the drill design. Core recovery is generally excellent for all core sizes, averaging 92% recovery. 1.4.3 Geological Logging All drill core is geologically logged for lithology, oxidation, alteration, structure, core recovery and RQD onto hard copy log sheets using a comprehensive set of logging codes. Zones of silic alteration and quartz veining determined during geological logging are selected for assaying. 1.4.4 Sampling Drill core is halved and sampled at varying intervals between 1-3m and are commonly 1m sample intervals. Most drill holes are completely sampled. All samples are of diamond core. 1.4.5 Analytical Methods All samples have undergone sample preparation at the ITS sample preparation facility in Padang prior to 250gm samples being forwarded to ITS laboratory in Jakarta for assay determination. Since 10/7/2004 the samples are crushed to 2mm before being split to an approximate 1.5kg sample, which is pulverised to -200mesh and split to a 250 gram sample then sent to ITS Jakarta. At ITS Jakarta Au is analysed by 50g fire assay, AAS determination, Zn, Cu, Pb, Fe, Mn and Ag are analysed using HCl/HClO4 digest, Mo, As, Sb and Te by XRF, Hg by cold vapour AAS and Bi by Hydride generation with AAS finish. Most samples are analysed for Au, Ag, Cu, Pb, Zn, As and Hg only but sample suites assayed have varied over time. OZ Minerals Limited Mineral Resources Explanatory Notes - 30 June 2008 - FINAL.doc Page 5 of 132 Mineral Resources 2008 Explanatory Notes 1.4.6 Assay Quality Control and Quality Assurance Approximately 3-5% of pulps have been duplicated and sent to ITS Jakarta and to SGS in Balikpapan both located in Indonesia. Standards were submitted at the rate of 1 for every 20 normal samples including blank material sourced locally. Some issues of low bias to all results for the 7 Au standard reference material sourced from Geostats Pty Ltd was indicated. ITS Jakarta has indicated that this may be due to the standard matrix composition. While the consistent low bias, in the order of 1-2%, is a concern, the low bias will not significantly affect the overall result as it only applies to the recent infill drilling. As a result of this a number of matrix matched standards are being prepared using Martabe ore material and will be certified for Au and Ag. Currently Au is the only element certified for the standard material being used, although base metal standards have been used for previous Newmont data. Blanks, duplicate pulps, blind pulp resubmissions and internal laboratory standards are also submitted and with no significant issues identified. 1.4.7 Bulk Density Bulk density is determined on all holes at regular interval using the Archimedean method utilising plastic wrap (gladwrap) sealing of the samples. Average bulk densities were assigned in the block models according to the lithologies, oxidation and mineralised zones. All bulk density data collected from oven dried drill core samples (0.2m lengths). 1.4.8 Interpretation Mineral Resource modelling is carried out using DatamineTM software. The distribution of the lithologies and alteration types is well understood, but the actual control on the high grade Au mineralisation is not well understood. Interpretation of the high-grade gold mineralisation between sections in the areas of the infill drilling required some minor modification for lithology and alteration indicating reasonably good local correlation. 1.4.9 Grade Estimation Ordinary Kriging was used to interpolate Au, Ag, Cu, AuCN, AgCN, CuCN, As and Hg grades into the block model.