Chathams research challenges theory on New Zealand prehistory

Aug 16, 2007
Chathams research challenges theory on New Zealand prehistory

A combination of geological and biological findings are lending weight to the possibility that the Chatham Islands were under water until three million years ago, and that New Zealand’s flora and fauna may have evolved in another large island near New Zealand.

Traditional thinking is that the islands of New Zealand split from the ancient super-continent Gondwanaland about 85 million years ago, and stayed above the oceans since then.

This is challenged by the findings of the multidisciplinary project that has been researching the Chathams, named the Chatham Islands Emergent Ark Survey. The team of biologists and geologists includes Dr Steve Trewick, Senior Lecturer at the Allan Wilson Centre for Molecular Ecology and Evolution. Dr Trewick was part of a team who visited the islands in 2004.

Findings include identification of remnants of deepwater limestone from about three million years ago, overlaid by beach deposits of sand, indicating that the Chathams may be much younger than previously thought. A further significant discovery was the previously unmapped formation in the southwest corner of the Chathams, volcanic rocks of a type that erupted and accumulated on the seashore. By using fossils from within the rocks and radiometric ageing, researchers found the formation was deposited between 2.5 million and 4.5 million years ago. The rocks were originally on the seabed, but now form the highest point on the Chathams, indicating that the entire land area was under the sea until uplift about two million years ago raised it to above the water level.

Biological findings now coming to hand are compatible with the geological findings, indicating that Chatham Islands birds and plants have been separated from their New Zealand relatives for up to three million years.

The final report on the Marsden-funded project is due next year. Participants include staff from Otago, Lincoln and Massey universities and GNS Science.

Source: Massey University

Explore further: Magnitude-7.2 earthquake shakes Mexican capital

add to favorites email to friend print save as pdf

Related Stories

Ancient Antarctic treasure trove discovered

Dec 27, 2012

(Phys.org)—The chance discovery of a 100 million year old fossil forest on an island east of New Zealand has unlocked new insights on ancient life close to the South Pole.

Earth Hour aims for hope in darkened world

Mar 25, 2011

Lights will go out around the world Saturday with hundreds of millions of people set to take part in the Earth Hour climate change campaign, which this year will also mark Japan's earthquake and tsunami.

Landmarks, cities worldwide unplug for Earth Hour

Mar 27, 2010

(AP) -- Europe's best known landmarks - including the Eiffel Tower, Big Ben and Rome's Colosseum - fell dark Saturday, following Sydney's Opera House and Beijing's Forbidden City in joining a global climate ...

Group says 3 more birds close to extinction

May 14, 2009

(AP) -- An Ethiopian lark, a Galapagos finch and a spectacularly colored hummingbird only recently discovered in Colombia have been added to the list of the world's most threatened species, an environmental group said Thursday. ...

Recommended for you

Magnitude-7.2 earthquake shakes Mexican capital

18 hours ago

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

User comments : 0

More news stories

Magnitude-7.2 earthquake shakes Mexican capital

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

New research on Earth's carbon budget

(Phys.org) —Results from a research project involving scientists from the Desert Research Institute have generated new findings surrounding some of the unknowns of changes in climate and the degree to which ...

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.