Deep Sea Minerals in the Pacific Islands Region: Occurrence, Potential and Case Studies`

Transcription

1 Deep Sea Minerals in the Pacific Islands Region: Occurrence, Potential and Case Studies` 1st DSM Project Regional Workshop 6th 8th June 2011 Tanoa International Hotel Nadi, Fiji Akuila Tawake SPC/SOPAC Division

2 Trend of Marine Minerals Exploration in the Region 1960s Mid 1970s: Manganese Nodules; Mid 1970s mid 1980s: Manganese Nodules, Precious Coral, Metalliferous Sediments, Phosphate. Early 1980s commencement of Cobalt-rich Crusts survey; 1982 and 1984 discovery of hydrothermal vents in the Lau Back-Arc Basin. Mid 1980s mid 2000: Maganese nodules, Cobaltt-rich Crusts and Seafloor Massive Sulphides; 1991 confirmation of high grade Seafloor Massive Sulphide (SMS) deposits in the Manus Basin PNG by the CSIRO offshore mining licence granted to Nautilus Minerals in PNG.

3 1978 Survey Early Manganese Nodules Survey in the Cook Islands Crosses indicate stations occupied on previous cruises 1980 Survey 0.3kg/m 2 Rarotonga 1.5kg/m 2 24kg/m 2 Surveyed in 1976, 1978, 1980 (x4), 1983; Nodule coverage can be as high as 90% and as low as less than 20%. 11kg/m 2

4 Japan-SOPAC Cooperative Study PNG, Solomon Islands, Vanuatu, Fiji, Tonga, Samoa, Niue, Cook Islands, Kiribati, Tuvalu, FSM, Marshall Islands

5 1985 Japan-SOPAC Cook Islands Survey 1985 Sampling Points 38 sample stations; Three samples at each station; Distance between samples: - 78 km - 39km Rarotonga

6 Japan-SOPAC Cooperative Study Programme Mineral Resources Phase 1 ( ) Stage 1 Stage 2 Phase 2 Phase 3 Phase 1 Phase 2 ( ) ( ) ( ) ( ) Manganese Nodules Cooks Kiribati Cooks Samoa Cooks Niue Tuvalu Kiribati Cobalt-rich Crust Kiribati Tuvalu Samoa Kiribati RMI FSM RMI Kiribati FSM Seafloor Massive Sulphides PNG Solomon Vanuatu Tonga Purpose Mineral Potential Evaluation Resource estimates Fiji Fiji Fiji Environmental survey

7 Minerals Occurrence in the Region Country MN CRC SMS Kiribati Cook Islands Tuvalu Samoa Tonga PNG Solomon Islands Vanuatu Fiji Marshall Islands Federated States of Micronesia Niue No economic potential for Metalliferous Sediment, Precious Coral and Phosphate

8 Recent Offshore Exploration in the Region Nautilus Minerals: - Ongoing exploration in PNG, Tonga and Solomon Islands. Neptune Minerals: - Previously exploring in NZ s EEZ. Korea Ocean Research and Development Institute (KORDI) - License granted in Tonga, and application in Fiji. Bluewater Metals: - Licenses granted in PNG, Solomon, Vanuatu and Tonga. The Bond Group and Others - Interests in exploring and developing Manganese Nodule resources in Cook Islands and Kiribati.

9 Manganese Nodules Cook Islands Manihiki Plateau Penrhyn Basin Samoa Basin Stage 1: three surveys (i.e. 1985, 1986, and 1990); Southern Seamounts Stage 2: one survey (i.e. 2000).

10 Estimated Manganese Nodules Abundance in the Central Area Abundance 1986 Survey 2000 Survey Area (km 2 ) Ratio (%) Area (km 2 ) Ratio (%) > 30kg/m 2 2, , kg/m 2 10, , kg/m 2 3, , <10kg/m , Total 16, , Maximum 50.86kg/m kg/m 2 Minimum 10.46kg/m kg/m 2 Average 33.56kg/m kg/m 2 Central Area 28.88kg/m 2

11 Variation in manganese nodules abundance in the EEZ of the Cook Islands

12 Cook Islands Manganese Nodule Estimates Using polygonal method of mineral resource estimates Nodule Abundance (dry) Area (km 2 ) Nodules (dry) Inferred Resources (Mt) Co Ni Cu Over 20 kg/m 2 33, kg/m 2 99,400 1, kg/m 2 92,200 1, kg/m 2 135, Cut-off 5 kg/m 2 359,700 4, Total (un-cut) 765,100 5,

13 Nodule Abundance Manganese Nodules Potential Surveyed at EEZs of 5 costal states Found high abundant area at the central area of Cook Waters

14 Cobalt-rich Crust Marshall Islands nine seamounts (MS01 MS09) were surveyed; 1998 four seamounts (MS10 MS13) were investigated; Existence of manganese crusts was confirmed in all 13 (MS01 MS13) seamounts; Majuro 2002 promising seamounts (MS01, MS11 and MS12) were resurveyed.

15 Topography and cross section of a Crust bearing seamount (MS01)

16 Estimates of crust and metal resources Seamounts Based on the 1996 and 1998 surveys Inferred Resources (Mt) Metal Resources (tonnes) Co Ni Cu Pt MS , ,184 26, MS ,393 59,875 10, MS , ,885 25, MS ,998 38,380 5, MS ,108 18,976 2, MS ,936 17,124 2, MS ,902 5,926 1,129 4 MS , ,542 21, MS ,370 93,617 19, MS ,945 78,977 8, MS , ,901 11, MS , ,139 9, MS , ,370 10, Total ,261, , ,

17 2002 Crust Resource Estimates Resource (t) = Area of crust distribution (km 2 ) x Crust Thickness (mm) x Specific gravity (2.0g/cm 3 ) Seamount Area (km 2 ) Inferred Resource Estimates Resource (Mt) Co Resource (Mt) Pt Resource MS MS MS Total 1, Resource estimates for MS01: 20.34Mt crust 1998 Resource estimates for MS11: 23.94Mt; MS12: 19.15Mt (t)

18 Crust thickness and metal contents at each seamount Based on the 1996 and 1998 surveys

19 Cobalt-rich Crust: Occurrence and Thickness Survey area: Kiribati: 1987, 1989, 1991, 2003 Samoa: 1990 Marshall:1996,1998, 2002, FSM: 1997, 1998, 2005

20 Triple Junction Area: 2 x 3 km Seafloor Massive Sulphide North Fiji Basin

21 Ore Showing in the Triple Junction

22 Study Area Triple Junction Resource Estimates Grade Cu (%) Zn (%) Au (g/t) Ag (g/t) West Area East Area Average Grade Observations by deep-sea TV camera confirm that there are at least seven (7) mounds in the Triple Junction Survey Area. Dimension of each deposit: 100m x 30m x 7m. Mineralised material Specific Gravity: 3.5g/cm 3. Inferred resources of each deposit: 70,000t. Total Inferred Resources: 6.93% Cu, 0.61% Zn, 0.85g/t Au and 24.39g/t Ag.

23 Resource Estimates Comparison Potential and Operating Mines Triple Junction (Fiji) Type of Deposit Resource (Mt) Cu (%) Zn (%) Average Grade Pb (%) Au (g/t) Ag (g/t) SMS 0.5 (Inferred) Solwara 1* (PNG) SMS 0.87 (Indicated) (Inferred) Whim Creek ~ (WA) Kidd Mine ^ (Canada) Ok Tedi Mine (PNG) VMS VMS Porphyry Cu-Au (resource & reserve) * (Golder Associates, 2008); ~ (Collins et al, 2004); ^ (Wilton, 1998)