Gannet Island

Gannet Island ("Karewa" in Māori) is a small island some 19 kilometres (12 miles) offshore from Kawhia on the west coast of New Zealand's North Island. Protected as a wildlife sanctuary, [ [http://interim.legislation.govt.nz/libraries/contents/om_isapi.dll?clientID=1315371708&infobase=pal_regs.nfo&jump=r1980-090&softpage=DOC Wildlife Sanctuary (Gannet Island) Order 1980] ] it was found to be the country's second largest breeding colony of Australasian Gannets in a 1980 census. [ [http://www.kingcountry.co.nz/20.html Gannet Island (Karewa)] ]

The island consists of the eroded remnant of a tuff ring, erupted about half a million years ago. It is considerably younger than, and compositionally distinct from, the nearby onshore Alexandra Volcanics (Mount Karioi and Mount Pirongia) and Okete Volcanics. It is located on the eastern edge of the North Taranaki Graben, rising 15 metres above sea level from a base about 65 metres deep. [R. M. Briggs, M. D. Rosenberg, P. J. de Lange, T. Itaya, P. R. King and R. C. Price. (1997). [http://www.rsnz.org/publish/nzjgg/1997/24.pdf Geology and geochemistry of Gannet (Karewa) Island, Tasman Sea: a rift-related nephelinitic tuff ring] , "New Zealand Journal of Geology and Geophysics", 40, 263-272.]

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