Resource Drilling of the Solwara 1 Seafloor Massive Sulfide (SMS) Deposit

Abstract

Nautilus Minerals is the world leader in exploration and development of deep ocean seafloor massive sulphide (SMS) resources. The company is currently focused on generating its resource pipeline in the Western Pacific and its first development project for recovery of high-grade copper, gold and silver mineralisation from its Solwara 1 site in the Bismarck Sea, Papua New Guinea.The Solwara 1 site is located at a water depth of 1,600 -1800 meters. Over 150 SMS seafloor surface samples have been collected from chimney structures during dives made by remote operated vehicles (ROVs).In order to obtain an understanding of the sub-surface mineralisation, Nautilus carried out 3 drilling programs between 2006 and 2008 which allowed the calculation of a Canadian NI43-101 compliant resource estimate. The initial 2006 campaign was based on conventional offshore surface driven drill equipment. In conjunction with the subsea remote technology industry, Nautilus subsequently developed an ROV operated seafloor drill system with improved drill core recovery and efficiency. This technology was developed further with a 2010 drill program to increase the available geological knowledge at Solwara 1 and adjacent prospects. This paper will provide an overview of Nautilus' SMS drilling requirements and recap the evolution of drilling technology and operations undertaken at Solwara 1 from 2006 to 2010. The paper will also discuss the potential of further developments in drilling techniques and equipment to increase or improve drilling depth, efficiency and data quality.

Characterisation of Mineralised Material from the Loki’s Castle Hydrothermal Vent on the Mohn’s Ridge

“…Bivalent Fe is the first Fe species removed from the hydrothermal fluid which initially leads to the formation of isocubanite (1), with a progressive concentration of Cu as chalcopyrite with dropping temperature, which is observed as exsolutions and overgrowths (2), and eventually bornite (3) [13]. Non-stoichiometric Cu sulphides are a final crystallisation stage (4), before decreased hydrothermal activity, and the oxidising effect of seawater causes the replacement of Cu-rich phases by Cu-poor minerals (5). An absence of bornite and that flow is still occurring (i.e., hydrothermal venting) suggests that current activity at Loki's Castle is early in this regime, perhaps stage 2.…”

“…Currently these minerals have land-based sources, but increased consumption ultimately requires an expansion and diversification of the reserves that society currently utilises. Recent deep sea research has identified a potential new source for a variety of critical metals, including copper, zinc, silver, and gold, from seafloor massive sulphides (SMS) [3][4][5]. These SMS deposits are present on the seafloor as active or inactive hydrothermal vent systems, and they may represent contemporary analogues of volcanogenic massive sulphide (VMS) deposits, a classic and long utilised source of base and precious metals [6].…”

“…The majority of previous SMS studies have tended to focus on deposit reviews and site discovery [3][4][5]7,8], deposit structure [9], general geochemistry [10], and water chemistry [11] trends. The purpose of this study is to, for the first time, perform a dedicated mineralogical study and to discuss the methods of characterisation for mineralised material from a recently discovered sulphide-bearing hydrothermal vent on the Arctic Mid-Ocean Ridge (AMOR).…”