New Zealand Land Formation

Biology

Ms Gibellini

2014

How Was NZ formed?

https://www.youtube.com/watch?v=pENq1ml2haA

http://www.youtube.com/watch?v=IfDhY32vP-c

170 MYA

•NZ was part of a land mass known as Gondwanaland

• http://www.sciencelearn.org.nz/Contexts/Ferns/Sci-Media/Animations-and-Interactives/Gondwana-animation

130 MYA• Africa, India and Madagascar

detached and moved away from Africa and South America creating the Atlantic Ocean

• Australia, NZ and Antarctica were attached to the southern end of South America and called Autralis. It straddled the South Pole BUT was ice free so temperate forests grew there for millions of years

80-60 MYA• Autralis began to break up, NZ or

Zealandia as it was known broke away from Australia and the Antarctic and the Tasman Sea formed.

• This took over 20 million years to occur!

• As it separated the land was stretched and thinned out which is why much of the land is under the sea today

• During this time period huge meteors and large scale volcanic activity resulted in the extinction of about half the plant and animals species on Earth including dinosaurs

23 MYA• Zealandia was at its lowest point, it is

thought there were only a few scattered islands above sea level, the largest in the Canterbury area

• As a result much of NZ is made from limestone (formed under the sea by shells of dead sea animals)

• Therefore almost all of our flora and fauna arrived from other land masses 25 MYA.

• NZ is currently rising out of the sea along the Alpine Fault as two tectonic plates collide

10 MYA

The Pacific Plate began to sink into the Australian Plate. Pressure caused cracks to form…and eventually the Alpine Fault.

NZ spilt in two and now lies across two plates and collide in sections creating new land, volcanic eruptions and uplift.

2.6 MYA• The Earth was exposed to periods of repeated

cooling – ice ages

• During glacial periods temperatures dropped as much as 4.5’C, heavy snow fell on NZ mountains. The snow hardened into ice and glaciers moved downhill into lower regions. Glaciers once covered the valleys from Fiordland to west Nelson

• Huge ice caps formed in the northern hemisphere locking up water and the sea level dropped by 100 metres exposing more coastal land in NZ. When the ice caps melted the sea level then rose again

In the Last 1.8 MY• Sothern Alps have risen

• Volcanic eruptions buried large areas of the North Island

• Huge glaciers spread out from the mountains

• The past 10 000 years has seen a fairly stable climate, temperatures have been rising for the past 7,000 years as a result so have sea levels.

Flora and Fauna• Up until several million years ago there were no terrestrial

mammals except bats and seas, most of the fauna was made up of insects and birds, such as unusual frogs and the tuatara

• The flora was mainly gondwanan plants such as giant kauri forests, podocarps and southern beech trees.

• There is a high rate of interspecific and intraspecific hybridisation in NZ plants and animals

• Following the separation from Gondwana species have came to NZ via the sea or airborne mostly from Australia. They arrived so long ago they are now almost unrecognisable as being decedents of Australian species.

• Some species have also travelled to NZ from New Caledonia

NZ Flora and Fauna• https://www.youtube.com/watch?v=Tw7kx5dHii8

• https://www.youtube.com/watch?v=KVSjtmtvF8M

• https://www.youtube.com/watch?v=KVSjtmtvF8M&ytsession=pPvPZ-Sgl3oE8O8TNu5EuuoOYFlywimtWdew-4WICdIN3_kQI7og_2aaIPgrQ6ei1XCTbx6ze3mhdGT5VaOfP5TVflCxGaNf7PUeETRZavaqFjMMaIv-FRgSqitxzZ0ufaA28YSC96ZdhTCvY9-XB4SijxtjuEYpxA2QNsGu4ewYiet0doaQ9feWuStr7oNdFM69v5X9hZRnEQbeVeliedSvKvXRp5R0BziKqqE3I05aNUw-pPho57w_HLx86fUBjMq7XTMI3fYiSUolZm3CQLP7H3lNgYGnY4CQT4SVMboGfaVUE-B_1LyW_1ybG6LKgQzIOj0eeog

Age of Man

• NZ was one of the last land masses to be colonised by humans around 1250AD by Maori and then 1790 by Europeans.

• Humans burnt forests, converted land to agriculture and removed 2/3 of the native forest, resulting in major ecological changes and erosion,

• Hunting and introduction of pests resulted in the extinction of many native species

Diversity

• Diversity – range of different species

• NZ has had two main forest types for the past 190million years – podocarps (kauri) and the southern beech.

• The rest of NZ was grassland and tussock in subalpine and low shrub land.

• Many of NZ native birds descend from Gondwanan stock, in the absence of mammals birds have evolved to fill niches usually filled by mammals eg Moa

• Others show clear links to Australian birds eg NZ Pigeon, Falcon and parrots

References• http://www.teara.govt.nz/en/geology-overview/page-11

• http://www.gns.cri.nz/Home/Learning/Science-Topics/NZ-Geology/NZ-s-Geological-History

• http://www.visitzealandia.com/what-is-zealandia/our-history/80-million-years-ago/

• http://en.wikipedia.org/wiki/Biodiversity_of_New_Zealand

• http://www.teara.govt.nz/en/1966/geology-new-zealands-geological-history

• http://www.teara.govt.nz/en/glaciers-and-glaciation/page-3

• http://www.gns.cri.nz/Home/Learning/Science-Topics/NZ-Geology/NZ-s-Geological-History

• http://www.teara.govt.nz/en/glaciers-and-glaciation/page-3

• http://www.teara.govt.nz/en/geology-overview/page-6

• http://www.visitzealandia.com/what-is-zealandia/our-history/80-million-years-ago/

• http://www.gns.cri.nz/Home/Learning/Science-Topics/Ocean-Floor/History-of-Zealandia

• http://en.wikipedia.org/wiki/Biodiversity_of_New_Zealand