Technical Information
As a result of extensive exploration there have been numerous reports published concerning the presence and the characteristics of the Chatham Rise rock phosphate deposit. These reports are publicly available and can be obtained through the Crown Minerals website at www.crownminerals.govt.nz.
In particular a report by David J. Cullen published in 1987 and entitled The Submarine Phosphate Resource on Central Chatham Rise (link) summarises the various data collected during the earlier exploration programmes and suggests that intensive surveys of limited areas of the crest of Chatham Rise have proved reserves of some 30 million tonnes of phosphorite; and the total resource is provisionally estimated at 100 million tonnes.
Link to Fertiliser magazine: Issue 47Fert Matters Jul 09