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**Geological Features and Research**:
– Zealandia is largely made up of two parallel ridges separated by a failed rift.
– The crust of Zealandia is approximately 20km thick.
– Movement along the Alpine Fault has shifted the southern part of Zealandia relative to the northern part.
– Zealandia has experienced repeated volcanism throughout its history.
– Zealandia is sometimes divided into North Zealandia and South Zealandia.
– Evidence supports Zealandia as a submerged continent.
– Various studies explore Zealandia’s geological characteristics.
– Zealandia’s geological evidence suggests the possibility of sinking.
– Studies reveal Archean and Paleoproterozoic zircons in southern New Zealand.
Exploration of rift basins in northwest Zealandia.
Research on Eocene compressional plate failure in northern Zealandia.
– Zealandia’s deepwater frontier has been explored.
– Marine and Petroleum Geology publication on Zealandia.
– Frontiers in Earth Science study on rift basins of northwest Zealandia.
– Geophysical Journal International research on Eocene compressional plate failure.

**Biogeography and Fossil Discoveries**:
– New Caledonia and New Zealand are outposts of the Antarctic flora.
– Fossilized forest logs from 180 million years ago can be seen at Curio Bay.
– Zealandia transitions from marine to terrestrial environments during glacial periods.
– A fossil mammal jaw from the Miocene was found in the Otago region in 2006.

**Political Divisions and Population Statistics**:
– Zealandia’s total land area is 286,660.25km.
– New Zealand constitutes 93.49% of Zealandia’s land area.
– New Caledonia and surrounding islands make up 6.48% of Zealandia.
– Various Australian territories account for the remaining 0.02% of Zealandia.
– Zealandia’s total human population is around 5.4 million people.
– Auckland is the largest city with approximately 1.7 million residents.
– New Zealand has the highest population on Zealandia with over 5 million people.
– New Caledonia has a population of around 268,767.
– Norfolk Island, Lord Howe Island, Cato Reef, Elizabeth Reef, and Middleton Reef have smaller populations.
– Zealandia’s population of 268,767 in 2014.
– 2016 Census QuickStats of Norfolk Island.
– Australian Bureau of Statistics data on Lord Howe Island.
– Population details from Stats NZ.

**Classification as a Continent**:
– The book ‘Zealandia: Our continent revealed’ presented evidence supporting Zealandia as a continent.
– A team of geologists concluded Zealandia meets the criteria for a submerged continent.
– The case for Zealandia as a continent was argued in the book by Nick Mortimer and Hamish Campbell.
– Geological and ecological evidence supports the classification of Zealandia as a continent.

**Media Coverage and External Resources**:
– BBC, Livescience, CNN, The Guardian, and The Telegraph have covered Zealandia’s discovery.
– Various external links provide detailed information on Zealandia.
– GSA Today article on Zealandia.
– E Tūhura – Explore Zealandia geoscience portal.
– Information on Zealandia from GNS NZ.
– Zealandia entry in Te Ara.
National Geographic Encyclopedia’s coverage of Zealandia.

Zealandia (Wikipedia)

Zealandia (pronounced /zˈlændiə/), also known as Te Riu-a-Māui (Māori) or Tasmantis (from Tasman Sea), is an almost entirely submerged mass of continental crust in Oceania that subsided after breaking away from Gondwana 83–79 million years ago. It has been described variously as a submerged continent, continental fragment, and microcontinent. The name and concept for Zealandia was proposed by Bruce Luyendyk in 1995, and satellite imagery shows it to be almost the size of Australia. A 2021 study suggests Zealandia is over a billion years old, about twice as old as geologists previously thought.

Topography of Zealandia, outlined in pink. The linear ridges running north-northeast (Colville to the west and Kermadec to the east, separated by the Havre Trough and Lau Basin) and southwest (the Resolution Ridge System) away from New Zealand are not considered part of Zealandia, nor are Australia (left), Vanuatu, or Fiji (top centre).

By approximately 23 million years ago, the landmass may have been completely submerged. Today, most of the landmass (94%) remains submerged beneath the Pacific Ocean. New Zealand is the largest part of Zealandia that is above sea level, followed by New Caledonia.

Mapping of Zealandia concluded in 2023. With a total area of approximately 4,900,000 km2 (1,900,000 sq mi), Zealandia is substantially larger than any features termed microcontinents and continental fragments. If classified as a microcontinent, Zealandia would be the world's largest microcontinent. Its area is six times the area of the next-largest microcontinent, Madagascar, and more than half the area of the Australian continent. Zealandia is more than twice the size of the largest intraoceanic large igneous province (LIP) in the world, the Ontong Java Plateau (approximately 1,900,000 km2 or 730,000 sq mi), and the world's largest island, Greenland (2,166,086 km2 or 836,330 sq mi). Zealandia is also substantially larger than the Arabian Peninsula (3,237,500 km2 or 1,250,000 sq mi), the world's largest peninsula, and the Indian subcontinent (4,300,000 km2 or 1,700,000 sq mi). Due to these and other geological considerations, such as crustal thickness and density, some geologists from New Zealand, New Caledonia, and Australia have concluded that Zealandia fulfills all the requirements to be considered a continent rather than a microcontinent or continental fragment. Geologist Nick Mortimer [de] commented that if it were not for the ocean level, it would have been recognised as such long ago.

Zealandia supports substantial inshore fisheries and contains gas fields, of which the largest known is the New Zealand Maui gas field, near Taranaki. Permits for oil exploration in the Great South Basin were issued in 2007. Offshore mineral resources include ironsands, volcanic massive sulfides and ferromanganese nodule deposits.

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