Assessing polymetallic nodule deposit in the Cook Island EEZ
•
1 j'aime•380 vues
With the use of GIS and geostatistical modelling techniques, we helped the Cook Island Seabed Authority to assess the potential for economic deposits of polymetallic nodule in their exclusive economic zone.
Recommandé
Recommandé
Contenu connexe
Tendances
Tendances (20)
Similaire à Assessing polymetallic nodule deposit in the Cook Island EEZ
Similaire à Assessing polymetallic nodule deposit in the Cook Island EEZ (20)
Plus de Kenex Ltd
Plus de Kenex Ltd (10)
Dernier
Dernier (20)
Assessing polymetallic nodule deposit in the Cook Island EEZ
- 1. POLYMETALLIC NODULE DEPOSITS in the COOK ISLANDS EEZ Using GIS to better assess the mineral and economic potential for polymetallic nodule deposits in the Cook Island Exclusive Economic Zone Elisa Puccioni Senior GIS Analyst at Kenex Ltd
- 2. The Cook Island Exclusive Economic Zone spread over 2 million of km2. The total cumulative land area of the Cook Islands is 237 km2 giving it an ocean/land area of c. 8440:1 This makes it a large Ocean Island State as well as a Pacific Small Island Developing State (PSIDS). The EEZ Seabed mineral exploration within the EEZ began in the 1960s. The 1970s surveys resulted in the discovery of significant MN resources. Surveys from 1985 to 2000s by the Japan-SOPAC delivered a range of data and models including a systematic survey of much of the EEZ. The complex morphology of the EEZ includes seamounts, abyssal hills, abyssal plains, atolls, troughs, and a major plateau. North Penrhyn Basin South Penrhyn Basin Samoan Basin Southwest Pacific Basin
- 3. Tourism 50% Services 38% Industry 8% Agriculture 4% $25,000 - $50,000 7% $10,000 - $25,000 28% 0-$10,000 51% No Income 13% $50,000+ 1% COOK ISLAND GDP % AND INCOME (2017) SEABED MINERAL EXPLORATION Deeper knowledge of the ocean’s resources Improve the Cook Islands’ quality of life New job positions and upskilling Cook Islanders More investment in services and education Environmental impact to be quantified Possible impact on Tourism and Fishery Cultural belief Logistics for processing and transportation - - - - + + + + + +
- 4. Tourism 50% Services 38% Industry 8% Agricultur e 4% $25,000 - $50,000 7% $10,000 - $25,000 28% 0-$10,000 51% No Income 13% $50,000+ 1% COOK ISLAND GDP % AND INCOME (2017) SEABED MINING EXPLORATION Deeper Knowledge of the ocean’s resources Increment in life quality New job positions and funding More investment in infrastructure and services Environmental Impact Tourism and Fisheries Impact Cultural Issues Logistic and infrastructure issues- - - - - - - + + + + + +
- 5. 20192017 2018 201620152013 2009 2012 SBMA 2009: the world first Seabed Act is created by the CI government 2012: the SBMA is established KENEX First projects with SMBA: GIS database from historic cruise data First geological potential model in the EEZ SBMA CI Prospecting and Exploration Regulations; the Seabed Minerals Amendment Act First official tender for exploration KENEX Probabilistic evaluation of the EEZ seabed mineral acreage and economic value KENEX/SBMA Enterprise GIS database for managing applications and licenses SBMA 2017: SBMA become part of the Marae Moana project KENEX/SBMA 2018: new GIS enterprise infrastructure and new areas for tender based on GIS models The new official tender opens TIME LINE Cook Islands Seabed Minerals Authority & Kenex collaboration
- 6. 20192017 2018 201620152013 2009 2012 SBMA 2009: the world first Seabed Act is created by the CI government 2012: the SBMA is established KENEX First projects with SMBA: GIS database from historic cruise data First geological potential model in the EEZ SBMA CI Prospecting and Exploration Regulations; the Seabed Minerals Amendment Act First official tender for exploration KENEX Probabilistic evaluation of the EEZ seabed mineral acreage and economic value KENEX/SBMA Enterprise GIS database for managing applications and licenses SBMA 2017: SBMA become part of the Marae Moana project KENEX/SBMA 2018: new GIS enterprise infrastructure and new areas for tender based on GIS models The new official tender opens TIME LINE Cook Islands Seabed Minerals Authority & Kenex collaboration
- 7. Cruises: 1974 - Tangaroa ORSTOM, Nomea – 1977 – R.V. Coriolis ORSTOM, Noumea – 1978 – R.V. Sonne CCOP/SOPAC – 1976-1981 Geological Society of Japan (JICA) – 1980 – Hakurei- Maru No. 2 JICA – 1983 – Hakurei_Maru GH83 JICA/SOPAC – 1985 & 1986 – Hakurei-Maru No. 2 Australian and New Zealand Governments – 1986 1987 – Thomas Washington Cruise JICA/SOPAC – 1990 – Hakurei-Maru No. 2 1997 - HMNZS Tui Cruise JICA – 2000 - Hakurei-Maru No. 2 Digital + Paper Data > 60 reports to check! The historic GIS database (HENS)
- 8. The historic GIS database (HENS) 40 shapefiles with locations, abundance and metal % data + 1,000 linked pictures
- 9. What is a geological potential model? Rigorous mineral systems approach Training and Evidence data availability GIS geostatistical model tools Target areas with the highest potential (known and new!) Data Driven or Expert Based models
- 10. Hydrogenetic Diagenetic Hydrothermal Halmyrolitic Biogenetic FIVE BROAD CATEGORIES Smooth surface texture (related to hydrogenetic) Intermediate to rough surface texture TWO GENERAL CLASSES DEPOSIT MODEL Nodule morphology and formation
- 11. Depth > 4,000m Siliceous/pelagic sediment (no calcareous) Below Carbonate Compensation Depth Low rate of sedimentation Deep steady currents CONDITIONS Large variations in bathymetry Two major ocean currents: - Antartic Bottom Water - Southern Equatorial Nodule abundances vary greatly from North to South LOCAL MORPHOLOGY DEPOSIT MODEL Local morphology and conditions
- 12. 01 02 03 WEIGHTS OF EVIDENCE MODEL Data-driven model. Prior probability value: 0.0001449 TRAINING POINTS 57 known deposits from the HENS DB with Mn Nodule Abundance > 30 kg/m2 STUDY AREA The extent rectangle of the EEZ (~ 4.000.000 km2) Geological potential model setting
- 13. Features tested: Geology Volcanic features Seafloor slope Bathymetry Carbonate compensation depth Sedimentation Geochemistry Step by Step A DEPOSIT MODEL for polymetallic nodules is defined based on the mineral system (Wyborn et al. 1995) All available data relating to the nodule deposit model in the EEZ is compiled DEPOSITION AND PRESERVATION Sediment Thickness CCD Mn/Fe Ratio FORMATION AND TRAP Seafloor Depth Seafloor Slope SOURCE OF METALS Volcanoes Lithology
- 14. Spatial correlated variables: Lower Cretaceous Geology <50 km distance from seamounts Low seafloor slope (0.1 deg) < -4800m depth < 100m sediment thickness Below CCD Mn/Fe ration < 1.2 Step by Step The Weights of Evidence model is run to assess and weight the data based on the relationship to known locations of nodules The data are statistically combined to create a single Geological Potential Map showing the areas most likely to contain economic nodule deposits.
- 15. Area (km2) 4.000.000 392,750 217,500 82,750 53 23 % 100% 10% 6% 2% 93% 40% Study Area Above prior probability Very prospective Highly prospective TP in very prospective TP in highly prospective
- 17. Geological Constrain for the Acreage Evaluation model (RESULTS ARE CONFIDENTIAL) Using the Results GIS geostatistical tools to interpolate nodule coverage CONSTRAINED TO GEOLOGICAL SUITABLE AREAS Estimated tonnes/km2 of nodules Derived % and estimated tonnes/km2 of metals Calculated eventual value per metal (US$/tonne)
- 18. Identify potential areas of research focus for any future exploration activity to increment the knowledge of the ocean and its resources. KNOWLEDGE Evaluate meaningfully the exploration acreage and possible nodule coverage through using probability values to constrain estimations. EVALUATION Prepare and select acreage for tender, determining areas to be set aside for economic, strategic and/or environmental reasons. PLANNING Both the HENS database and the modelling results are part of the tender package to promote investment in the CIEEZ. MARKETING Sharing the results enables the industry to make an estimate of the geological potential of given locations and plan exploration programmes. INDUSTRY