Zealandia (continent)

From Wikipedia, the free encyclopedia

This article or section does not adequately cite its references or sources.
Please help improve this article by adding citations to reliable sources. (help, get involved!)
This article has been tagged since February 2007.

Topography of Zealandia. The linear ridges running NNE and SSW away from New Zealand are not considered part of the continent, nor are Australia (upper left), Fiji or Vanuatu (top centre).

This article is about the continent. For the ship, see Zealandia.

Zealandia, also known as the New Zealand continent, is a nearly submerged continent that sank after breaking away from Australia 60-85 million years ago^[1] and from Antarctica between 130 and 85 million years ago. Most of it (93%) is now submerged under the Pacific Ocean.

Zealandia is 3,500,000 km² in area, almost half the size of Australia. It is unusually long and narrow, stretching from New Caledonia in the north to beyond New Zealand's sub-antarctic islands in the south (from latitude 19° south to 56° south,^[1] analogous to ranging from Haiti to Hudson Bay or from Sudan to Sweden in the northern hemisphere). New Zealand is the largest part of Zealandia that is above sea level, followed by New Caledonia.

The major submerged parts of Zealandia are the Lord Howe Rise, Challenger Plateau, Campbell Plateau, Norfolk Ridge and the Chatham Rise. Smaller provinces include the Louisiade Plateau, Mellish Rise, Kenn Plateau, Chesterfield Plateau, and Dampier Ridge.^[2] The seemingly separate Gilbert Seamount is also part of the New Zealand continent.^[3]

About 25 million years ago, the southern part of Zealandia (on the Pacific Plate) began to shift relative to the northern part (on the Indo-Australian Plate). The resulting displacement by approximately 500 kilometres (300 mi) along the Alpine Fault is evident in geological maps. Compression across the plate boundary has uplifted the Southern Alps.

Zealandia supports substantial inshore fisheries and contains New Zealand's largest gas field. Some parts of it may be mined in the future.

[edit] References

^ ^a ^b Keith Lewis; Scott D. Nodder and Lionel Carter (2007-01-11). Zealandia: the New Zealand continent. Te Ara - the Encyclopedia of New Zealand. Retrieved on 2007-02-22.
^ Mortimer, Nick (2006). "Zealandia" in Australian Earth Sciences Convention. {{{booktitle}}}: 4. Retrieved on 2007-03-28.
^ Wood, Ray; Vaughan Stagpoole, Ian Wright, Bryan Davy and Phil Barnes (2003). New Zealand's Continental Shelf and UNCLOS Article 76 (PDF), Institute of Geological and Nuclear Sciences series 56; NIWA technical report 123, Wellington, New Zealand: Institute of Geological and Nuclear Sciences Limited; National Institute of Water and Atmospheric Research, 16. Retrieved on 2007-02-22. “The continuous rifted basement structure, thickness of the crust, and lack of seafloor spreading anomalies are evidence of prolongation of the New Zealand land mass to Gilbert Seamount.”