Date: 24/03/2015 14:34:48
From: Bubblecar
ID: 697321
Subject: World's Largest Impact Craters Found in Oz

Australian scientists have uncovered what is believed to be the largest asteroid impact zone ever found on Earth, in central Australia.

A team lead by Dr Andrew Glikson from the Australian National University (ANU) said two ancient craters found in central Australia were believed to have been caused by one meteorite that broke in two.

“They appear to be two large structures, with each of them approximately 200 kilometres,” Dr Glikson said.

“So together, jointly they would form a 400 kilometre structure which is the biggest we know of anywhere in the world.

“The consequences are that it could have caused a large mass extinction event at the time, but we still don’t know the age of this asteroid impact and we are still working on it.”

The material at both impact sites appears to be identical which has led researchers to believe they are from the same meteorite.

Over millions of years the obvious craters have disappeared, but geothermal research drilling revealed the secret history hidden under an area including South Australia, Queensland and the Northern Territory.

“The next step will be more research, hopefully deep crust seismic traverses,” Dr Glikson said.

“Under the Cooper Basin and Warburton Basin we don’t have that information and our seismic information covers up to five kilometres and some other data such as seismic tomography and magnetic data.

“The mantle underneath has been up-domed which is a very promising indication of a major event.”

There are many unanswered questions about the underground site and whether the twin asteroid impact could have affected life on earth at the time.

“When we know more about the age of the impact, then we will know whether it correlates with one of the large mass extinctions .

“At this stage we do not have all the answers, but there has been a lot of interest and people are certainly interested in any impact on the dinosaurs.”

The research has been published in the geology journal Tectonophysics.

http://www.abc.net.au/news/2015-03-23/worlds-largest-asteroid-impact-zone-found-in-central-australia/6341408

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Date: 24/03/2015 14:39:36
From: The Rev Dodgson
ID: 697324
Subject: re: World's Largest Impact Craters Found in Oz

Bubblecar said:


“The consequences are that it could have caused a large mass extinction event at the time,

As opposed to the more common small and medium sized mass extinctions.

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Date: 24/03/2015 14:43:20
From: Bubblecar
ID: 697328
Subject: re: World's Largest Impact Craters Found in Oz

The Rev Dodgson said:


Bubblecar said:

“The consequences are that it could have caused a large mass extinction event at the time,

As opposed to the more common small and medium sized mass extinctions.

I think they mean “global”.

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Date: 24/03/2015 14:43:32
From: Postpocelipse
ID: 697329
Subject: re: World's Largest Impact Craters Found in Oz

The Rev Dodgson said:


Bubblecar said:

“The consequences are that it could have caused a large mass extinction event at the time,

As opposed to the more common small and medium sized mass extinctions.

As opposed to being a nice fireworks show with laserlights and sound choreography.

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Date: 24/03/2015 14:46:38
From: Cymek
ID: 697333
Subject: re: World's Largest Impact Craters Found in Oz

Bubblecar said:


The Rev Dodgson said:

Bubblecar said:

“The consequences are that it could have caused a large mass extinction event at the time,

As opposed to the more common small and medium sized mass extinctions.

I think they mean “global”.

Impact local, consequences global

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Date: 25/03/2015 10:44:26
From: mollwollfumble
ID: 697541
Subject: re: World's Largest Impact Craters Found in Oz

The Rev Dodgson said:


Bubblecar said:

“The consequences are that it could have caused a large mass extinction event at the time,

As opposed to the more common small and medium sized mass extinctions.

There really are “small and medium sized mass extinctions”, and they are more common. There are five well-known large mass extinctions, Ordovician-Silurian, late Devonian, Permian, Triassic-Jurassic and Cretaceous-Tertiary.

By the way, every large mass extinction has been matched to geological activity.

> Cooper Basin. The mantle underneath has been up-domed which is a very promising indication of a major event.

I’ve always thought that it was a mantle hot spot like that in Hawaii.

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Date: 25/03/2015 11:18:29
From: Cymek
ID: 697547
Subject: re: World's Largest Impact Craters Found in Oz

mollwollfumble said:


The Rev Dodgson said:

Bubblecar said:

“The consequences are that it could have caused a large mass extinction event at the time,

As opposed to the more common small and medium sized mass extinctions.

There really are “small and medium sized mass extinctions”, and they are more common. There are five well-known large mass extinctions, Ordovician-Silurian, late Devonian, Permian, Triassic-Jurassic and Cretaceous-Tertiary.

By the way, every large mass extinction has been matched to geological activity.

> Cooper Basin. The mantle underneath has been up-domed which is a very promising indication of a major event.

I’ve always thought that it was a mantle hot spot like that in Hawaii.

Would geological activity be the only way you could get a large mass extinction even if say that geological activity was caused by an asteroid impact. I suppose if all ice on the planet become water if might also cause mass extinction unless everything learn to swim

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