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Coordinates: 40°S 170°E / 40°S 170°E / -40; 170

Topography of Zealandia. 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
Ridge
System) away from New Zealand
New Zealand
are not considered part of the continental fragment, nor are Australia
Australia
(upper left), Fiji
Fiji
or Vanuatu
Vanuatu
(top centre).[1]

Zealandia
Zealandia
( /ziːˈlændiə/), also known as the New Zealand
New Zealand
continent or Tasmantis,[2] is a nearly submerged mass of continental crust that sank after breaking away from Australia
Australia
60–85 million years ago, having separated from Antarctica
Antarctica
between 85 and 130 million years ago.[3] It has variously been described as a continental fragment, a microcontinent, a submerged continent, and a continent.[4] The name and concept for Zealandia
Zealandia
was proposed by Bruce Luyendyk in 1995.[5]. Zealandia's status as a continent is not universally accepted, but New Zealand geologist Nick Mortimer has commented that "if it wasn't for the ocean" it would have been recognized as such long ago.[6] The land mass may have been completely submerged about 23 million years ago,[7][8] and most of it (93%) remains submerged beneath the Pacific Ocean.[9] With a total area of approximately 4,920,000 km2 (1,900,000 sq mi), it is the world's largest current microcontinent, more than twice the size of the next-largest microcontinent and more than half the size of the Australian continent. As such, and due to other geological considerations, such as crustal thickness and density, it is arguably a continent in its own right.[10] This was the argument which made news in 2017,[11] when geologists from New Zealand, New Caledonia
New Caledonia
and Australia
Australia
concluded that Zealandia
Zealandia
fulfills all the necessary requirements to be considered a continent, rather than a microcontinent or continental fragment.[4] Zealandia
Zealandia
supports substantial inshore fisheries and contains gas fields, of which the largest known is New Zealand's Maui gas field, near Taranaki. Permits for oil exploration in the Great South Basin were issued in 2007.[12] Offshore mineral resources include iron sands, volcanic massive sulfides and ferromanganese nodule deposits.[13]

Contents

1 Geology

1.1 Classification as a continent

2 Biogeography 3 Political divisions 4 Population 5 References 6 Further reading 7 External links

Geology[edit]

Topographic map of Zealandia

Most of Zealandia
Zealandia
is underwater. Ball's Pyramid, near Lord Howe Island, is one place where it rises above sea level

Zealandia
Zealandia
is largely made up of two nearly parallel ridges, separated by a failed rift, where the rift breakup of the continent stops and becomes a filled graben. The ridges rise above the sea floor to heights of 1,000–1,500 m (3,300–4,900 ft), with few rocky islands rising above sea level. The ridges are continental rock, but are lower in elevation than normal continents because their crust is thinner than usual, approximately 20 km (12 mi) thick, and consequently they do not float as high above the Earth's mantle. About 25 million years ago, the southern part of Zealandia
Zealandia
(on the Pacific Plate) began to shift relative to the northern part (on the Indo-Australian Plate). The resulting displacement by approximately 500 km (310 mi) along the Alpine Fault
Alpine Fault
is evident in geological maps.[14] Movement along this plate boundary has also offset the New Caledonia
New Caledonia
Basin from its previous continuation through the Bounty Trough. Compression across the boundary has uplifted the Southern Alps, although due to rapid erosion their height reflects only a small fraction of the uplift. Farther north, subduction of the Pacific Plate has led to extensive volcanism, including the Coromandel and Taupo Volcanic Zones. Associated rifting and subsidence has produced the Hauraki Graben
Graben
and more recently the Whakatane Graben
Graben
and Wanganui Basin. Volcanism on Zealandia
Zealandia
has also taken place repeatedly in various parts of the continental fragment before, during and after it rifted away from the supercontinent Gondwana. Although Zealandia
Zealandia
has shifted approximately 6,000 km (3,700 mi) to the northwest with respect to the underlying mantle from the time when it rifted from Antarctica, recurring intracontinental volcanism exhibits magma composition similar to that of volcanoes in previously adjacent parts of Antarctica
Antarctica
and Australia. This volcanism is widespread across Zealandia
Zealandia
but generally of low volume apart from the huge mid to late Miocene
Miocene
shield volcanoes that developed the Banks and Otago
Otago
Peninsulas. In addition, it took place continually in numerous limited regions all through the Late Cretaceous and the Cenozoic. However, its causes are still in dispute. During the Miocene, the northern section of Zealandia
Zealandia
(Lord Howe Rise) might have slid over a stationary hotspot, forming the Lord Howe Seamount
Seamount
Chain. Zealandia
Zealandia
is occasionally divided by scientists into two regions, North Zealandia
Zealandia
(or Western Province) and South Zealandia
Zealandia
(or Eastern Province), the latter of which contains most of the Median Batholith crust. These two features are separated by the Alpine Fault
Alpine Fault
and Kermadec Trench
Kermadec Trench
and by the wedge-shaped Hikurangi Plateau, and are moving separately to each other.[15] Classification as a continent[edit] The case for Zealandia
Zealandia
being a continent in its own right was argued by Nick Mortimer and Hamish Campbell in their book Zealandia: Our continent revealed in 2014, citing geological and ecological evidence to support the proposal.[16] In 2017, a team of eleven geologists from New Zealand, New Caledonia and Australia
Australia
concluded that Zealandia
Zealandia
fulfills all the requirements to be considered a drowned continent, rather than a microcontinent or continental fragment.[4] This was widely covered by news media.[17][18][19]

Biogeography[edit] New Caledonia
New Caledonia
lies at the northern end of the ancient continent, while New Zealand
New Zealand
rises at the plate boundary that bisects it. These land masses are two outposts of the Antarctic Flora, including Araucarias and Podocarps. At Curio Bay, logs of a fossilized forest closely related to modern Kauri
Kauri
and Norfolk Pine
Norfolk Pine
can be seen that grew on Zealandia
Zealandia
about 180 million years ago during the Jurassic
Jurassic
period, before it split from Gondwana.[20] These were buried by volcanic mud flows and gradually replaced by silica to produce the fossils now exposed by the sea. During glacial periods, more of Zealandia
Zealandia
becomes a terrestrial rather than a marine environment. Zealandia
Zealandia
was originally thought to have no native land mammal fauna, but the discovery in 2006 of a fossil mammal jaw from the Miocene
Miocene
in the Otago
Otago
region shows otherwise.[21] Political divisions[edit]

Exclusive economic zone
Exclusive economic zone
of New Zealand
New Zealand
and continental shelf boundaries for much of Zealandia

The total land area (including inland water bodies) of Zealandia
Zealandia
is 286,655 km2 (110,678 sq mi). Of this, New Zealand comprises the majority, at 267,988 km2 (103,471 sq mi or 93%) which includes the mainland, nearby islands, and most outlying islands including the Antipodes Islands, Auckland Islands, Bounty Islands, Campbell Islands, and Chatham Islands
Chatham Islands
(but not the Kermadec Islands or Macquarie Island
Island
(Australia), which are part of the rift). New Caledonia
New Caledonia
and the islands surrounding it comprise some 18,576 km2 (7,172 sq mi or 7%) and the remainder is made up of various territories of Australia
Australia
including Lord Howe Island Group (New South Wales) at 56 km2 (22 sq mi or 0.02%), Norfolk Island
Island
at 35 km2 (14 sq mi or 0.01%), as well as Elizabeth and Middleton Reefs ( Coral Sea Islands
Coral Sea Islands
Territory) with 0.25 km2 (0.097 sq mi). Population[edit] The total human population of Zealandia
Zealandia
today is about 5 million people.

New Zealand
New Zealand
– 4,823,193[22] New Caledonia
New Caledonia
– 268,767[23] Norfolk Island
Island
– 2,210[24] Lord Howe Island
Lord Howe Island
Group – 382[25] Elizabeth Reef
Elizabeth Reef
and Middleton Reef
Middleton Reef
– 0

References[edit]

^ "Figure 8.1: New Zealand
New Zealand
in relation to the Indo-Australian and Pacific Plates". The State of New Zealand’s Environment 1997. 1997. Retrieved 20 April 2007. [permanent dead link] ^ Danver, Steven L. (22 December 2010). Popular Controversies in World History: Investigating History's Intriguing Questions. ABC-CLIO. p. 187. ISBN 978-1-59884-078-0. Archived from the original on 5 August 2016. Zealandia
Zealandia
or Tasmantis, with its 3.5 million square km territory being larger than Greenland,...  ^ Keith Lewis; Scott D. Nodder; Lionel Carter (11 January 2007). "Zealandia: the New Zealand
New Zealand
continent". Te Ara: The Encyclopedia of New Zealand. Archived from the original on 26 June 2013. Retrieved 22 February 2007.  ^ a b c Mortimer, Nick; Campbell, Hamish J.; et al. (2017). "Zealandia: Earth's Hidden Continent". GSA Today. 27. doi:10.1130/GSATG321A.1. Archived from the original on 17 February 2017.  ^ Luyendyk, Bruce P. (April 1995). "Hypothesis for Cretaceous rifting of east Gondwana
Gondwana
caused by subducted slab capture". Geology. 23 (4): 373–376. doi:10.1130/0091-7613(1995)023<0373:HFCROE>2.3.CO;2.  ^ cite url=https://www.sciencenewsforstudents.org/article/zealandia-continent

^ "Searching for the lost continent of Zealandia". The Dominion Post. 29 September 2007. Retrieved 9 October 2007. We cannot categorically say that there has always been land here. The geological evidence at present is too weak, so we are logically forced to consider the possibility that the whole of Zealandia
Zealandia
may have sunk.  ^ Campbell, Hamish; Gerard Hutching (2007). In Search of Ancient New Zealand. North Shore, New Zealand: Penguin Books. pp. 166–167. ISBN 978-0-14-302088-2.  ^ Wood, Ray; Stagpoole, Vaughan; Wright, Ian; Davy, Bryan; Barnes, Phil (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. p. 16. Archived from the original (PDF) on 21 February 2007. Retrieved 22 February 2007. 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.  ^ Mortimer, Nick; Hamish Campbell (2014). Zealandia: Our continent revealed. North Shore, New Zealand: Penguin Books. pp. 72ff. ISBN 978-0-14-357156-8 ^ "Zealandia: Is there an eighth continent under New Zealand?". BBC News. 17 February 2017. Archived from the original on 28 March 2017. Retrieved 26 March 2017.  ^ " Great South Basin
Great South Basin
– Questions and Answers". 11 July 2007. Archived from the original on 14 October 2008. Retrieved 18 April 2008.  ^ "New survey published on NZ mineral deposits". 30 May 2007. Archived from the original on 16 October 2008. Retrieved 18 April 2008.  ^ "Figure 4. Basement rocks of New Zealand". UNCLOS Article 76: The Land mass, continental shelf, and deep ocean floor: Accretion and suturing. Archived from the original on 27 September 2007. Retrieved 21 April 2007.  ^ Mortimer, Nick; Hamish Campbell (2014). Zealandia: Our continent revealed. North Shore, New Zealand: Penguin Books. pp. 120ff. ISBN 978-0-14-357156-8.  ^ Yarwood, V. Book
Book
review of "Zealandia: Our continent revealed" Archived 29 July 2017 at the Wayback Machine., New Zealand
New Zealand
Geographic, November–December 2014. Retrieved 30 July 2017. ^ Potter, Randall (16 February 2017). "Meet Zealandia: Earth's latest continent". CNN. Archived from the original on 17 February 2017.  ^ Hunt, Elle (16 February 2017). " Zealandia
Zealandia
– pieces finally falling together for continent we didn't know we had". The Guardian. Archived from the original on 26 February 2017.  ^ East, Michael (16 February 2017). "Scientists discover 'Zealandia' – a hidden continent off the coast of Australia". The Telegraph. Archived from the original on 18 February 2017.  ^ Fossil
Fossil
forest: Features of Curio Bay/Porpoise Bay Archived 17 October 2008 at the Wayback Machine. Retrieved on 6 November 2007 ^ Campbell, Hamish; Gerard Hutching (2007). In Search of Ancient New Zealand. North Shore, New Zealand: Penguin Books. pp. 183–184. ISBN 978-0-14-302088-2.  ^ "Population clock as at Sunday, 08 Oct 2017 at 11:48:07 a.m." 8 October 2017. Archived from the original on 12 July 2017. Retrieved 7 October 2017.  ^ "268 767 habitants en 2014". ISEE. Archived from the original on 13 November 2014. Retrieved 16 November 2014.  ^ "Norfolk Island". The World Factbook. CIA. Archived from the original on 3 July 2015. Retrieved 22 July 2015.  ^ Australian Bureau of Statistics
Australian Bureau of Statistics
(27 June 2017). "Lord Howe Island (State Suburb)". 2016 Census QuickStats. Retrieved 7 July 2017. 

Further reading[edit]

Mortimer, N., and Campbell, H. (2014) Zealandia: Our continent revealed. Auckland: Penguin Books
Penguin Books
(NZ). ISBN 978-0143571568

External links[edit]

Zealandia
Zealandia
the New Zealand
New Zealand
(drowned) Continent, from Te Ara

v t e

Continents of the world

   

Africa

Antarctica

Asia

Australia

Europe

North America

South America

   

Afro-Eurasia

America

Eurasia

Oceania

   

Former supercontinents Gondwana Laurasia Pangaea Pannotia Rodinia Columbia Kenorland Nena Sclavia Ur Vaalbara

Historical continents Amazonia Arctica Asiamerica Atlantica Avalonia Baltica Cimmeria Congo craton Euramerica Kalaharia Kazakhstania Laurentia North China Siberia South China East Antarctica India

   

Submerged continents Kerguelen Plateau Zealandia

Possible future supercontinents Pangaea
Pangaea
Ultima Amasia Novopangaea

Mythical and hypothesised continents Atlantis Kumari Kandam Lemuria Meropis Mu Hyperborea Terra Australis

See also Regions of the world Continental fragment

Book Category

v t e

Oceanic features of Zealandia

Major divisions

Western Province (North Zealandia) Eastern Province (South Zealandia)

Plateaux, ridges, and rises

Bellona Plateau Bounty Platform Campbell Plateau Challenger Plateau Chatham Rise Chesterfield Plateau Colville-Lau Ridge Dampier Ridge Fairway Ridge Kenn Plateau Lord Howe Plateau Loyalty Ridge Mellish Rise Norfolk Ridge Northland Plateau Puysegur Ridge Resolution Ridge Three Kings Ridge West Norfolk Ridge

Troughs and trenches

Bellona Gap Bellona Trough Bounty Trough Havre Trough Hikurangi Trench New Caledonia
New Caledonia
Trough Puysegur Trench

Oceanic basins

Bellona Basin Campbell Basin Canterbury Basin Capel Basin Cato Basin Chatham Slope Dampier Basin Deepwater Taranaki
Taranaki
Basin East Coast Basin Emerald Basin Fairway Basin Faust Basin Gower Basin Great South Basin Middleton Basin Monowai Basin Moore Basin New Caledonia
New Caledonia
Basin Norfolk Basin Northeast Slope Northland Basin Outer Campbell Basin Pegasus Basin Pukaki Basin Raukumara Basin Reinga Basin South Fiji
Fiji
Basin South Loyalty Basin Taranaki
Taranaki
Basin Wanganui Basin West Coast Basin

Seamounts

Banc Capel Capel Guyot Clark Seamount Flinder's Seamount Gifford Guyot Gilbert Seamount Graveyard Seamounts Havre Seamount Lord Howe Seamount
Seamount
Chain Rumble III Seamount Rumble IV Seamount Rumble V Seamount South Kermadec Ridge
Ridge
Seamounts Tangaroa Seamount Tasmantid Seamount
Seamount
Chain

Other

Alpine Fault Hikurangi Margin Kermadec Plate Maari oil field Maui gas fi

.