This paper by Lionel Carter is a summary of the
distribution of ironsand (magnetite and ilmenite)
in sediments on the continental shelf off western
New Zealand (PDF, 1.3 MB). It was published in the
New Zealand Journal of Geology &
Geophysics (1980).
A detailed account of the iron resources of New
Zealand, prepared by Tony Christie and Bob
Braithwaite, from the Crown minerals section of the
Ministry of Economic Development website.