Mining Magazine > Panorama > DFI announces first NI 43-101 compliant resource estimate for a marine sedimentary exhalative (SEDEX) deposit

Diamond Fields International (DFI) announced on July 26, the world’s first NI 43-101 compliant resource estimate for a marine sedimentary exhalative (SEDEX) deposit. The report, which was compiled by ACA Howe International, was based on 589 cores and relates to DFI’s Atlantis II sea-floor deposit, which is located in the Red Sea approximately 115km west of Jeddah, Saudi Arabia.
The independent report noted several things about the deposit. The estimated tonnages and grades include both high and low grade areas of the Atlantis II Deeps, and the average total thickness of the deposit is known to exceed 30m. Higher grade copper, zinc and silver mineralisation is contained within the south west, west and eastern sub-basins, where metre core intersects of up to 22.47% zinc, 2.05% copper and 338 g/t silver have been obtained.
Ian Ransome, CEO of DFI, said: "This is a mining first. Combined with the substantial data DFI already has on the Atlantis II deposit and the Company's experience as one of only a handful of companies to commercially mine the oceans, uniquely places Diamond Fields to develop the Atlantis II deposit. Together with its joint venture partner Manafa International of Saudi Arabia, the company now moves to the feasibility and financing stages of developing this world-class marine deposit."
The Atlantis basin is comprised of four interlinked sub-basins lying about 2km below sea level. DFI has been exploring the deposit with Manafa International, its joint venture partner.
The deposit was first discovered in 1965, and about US$28 million (at 1970s prices) was spent exploring it. The historic resource estimates reference the presence of significant co-product metal values including manganese, lead, cobalt, cadmium and gold. Feasibility work is now underway to determine the true value of the co-product metal mineralisation. DFI and Manafa have obtained the records and data generated during the original study, and have inspected the sediment cores.
A pre pilot test mining study undertaken by Preussag established that the mineralised mud of the Atlantis II Deeps can be continuously mined and concentrated at sea, using regular flotation techniques.