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New exploration interest in offshore phosphate deposits
26 April 2010 - New exploration interest is developing in ocean floor deposits of phosphate nodules on the relatively shallow Chathams Rise which extends east of the South Island to the Chatham Islands.
Sources: Widespread Energy and Lindsay Clark
Widespread Energy Ltd (operator) and associated company Widespread Portfolios Ltd has been granted a four-year continental shelf licence 50270 over a 4,726 sq km area on the Chathams Rise.
Chris Castle, managing director of both Widespread companies, said that the joint venture had moved to raise further capital, to undertake marine environment studies and a re-analysis of historic data.
The Chathams Rise phosphate deposits underwent an earlier period of exploration between the 1960’s and 1980’s following the original discovery by NZ Geological Survey staff in 1952.
A number of other oceanographic cruises in this period established that extensive phosphate deposits occur along 400 km of the crest of the Chatham Rise, at depths of 400 m or less.
The phosphate occurs in phophatised seabed chalky limestone in the form of phosphorite nodules on the seafloor. The nodules were formed in Late Miocene times, they have a diameter ranging from 2 mm to over 150 mm. The layers reaching up to 0.7 m thick.
The earlier surveys in this area indicate “proved reserves” of 30 million tonnes with total resource potential of 100 million tonnes.
The phosphorus content of the nodules was 9.4%, higher than manufactured super-phosphate, but usually lower than most phosphate now imported into New Zealand. Most phosphate rock, a core input to fertiliser manufacture, currently comes from Morocco.
Currently more than a million tonnes of phosphate is imported into New Zealand.
At current prices of around US$200/t, the commodity value of imported phosphate adds to around $300m a year. Cost of freight adds a further $170m a year.
Mr Castle said a recent capital raising had mostly come from two experienced overseas investors, John Quinn, a former managing director of Newcrest Mining and James Askew, presently chairman of OceanaGold, both of whom are shareholders in Widespread Energy.
