Kermadec, based in the northern waters of New Zealand, is one of the key seafloor massive sulphide (SMS) projects of Neptune Minerals. The company is engaged in exploring and developing precious and base metal SMS deposits. SMS is a high grade hydrothermal deposit containing high levels of copper, zinc and lead along with high gold and silver content,
Neptune Minerals has been granted exploration licences for an aggregate of 261,146km² in the territorial waters of New Zealand and Papua New Guinea. It also has licences in the Federated States of Micronesia and Vanuatu.
Neptune, along with Canyon Offshore, Century Subsea and Seacore, undertook coring and sea-floor mapping in the company’s granted prospecting licence (Kermadec PL 39-195), within New Zealand’s 200 nautical mile Exclusive Economic Zone.
First commercial drilling
The first commercial exploration drilling programme for SMS took place in 2005.
During the programme, 23 14m-deep core holes were drilled and 29 sea-floor samples were collected. Complete analysis, petrophysical measurements and high resolution core mineralogy were also undertaken during the drilling programme.
Samples of 11.2g/t gold, 122g/t silver, 8.1% copper, 5% zinc and 0.5% lead was also discovered from drilling samples of SMS chimneys submitted for metallurgical properties.
During November 2006, Kermadec PL 39 195 was renewed to cover 3447km² area.
In 2006 Neptune Minerals signed a contract with Norway’s Geo Subsea to proceed with the exploration of Kermadec 07. The exploration comprised high resolution sea-floor mapping and SMS sampling operations over numerous targets.
Geo Subsea oversaw the offshore survey, maintenance, construction and subsea engineering operations along with high resolution acoustic and geophysical mapping of SMS targets in PL 39 195.
The exploration began in May 2007 and was complete by August. The company discovered two new hydrothermally inactive SMS zones at Rumble II West, with sulphide chimneys up to 13m high and mounds 100m long.
In 2008, the company was in discussion with New Zealand regulator Crown Minerals and with other government departments, non-government organisations and interested community groups to ensure an agreed application process.
Neptune plans to initiate trial mining of Kermadec assets by 2011. The company acquired rights over Kermadec in October 2002, but they will expire in October 2010.
The company submitted its first mining licence application in July 2008 to the New Zealand Government for the Kermadec PL39 195 area. With the licence granted, the company will begin to define SMS resources and conduct environmental assessments.