Re: 260-Million-Year-Old Leaf - interesting photo

From: Eric Stevens (eric.stevens_at_sum.co.nz)
Date: 11/10/04


Date: Wed, 10 Nov 2004 21:04:48 +1300

On Tue, 09 Nov 2004 23:53:04 GMT, Seppo Renfors
<Renfors@not.on.com.au> wrote:

>
>
>Eric Stevens wrote:
>>
>> On Tue, 09 Nov 2004 17:24:44 +1300, Eric Stevens
>> <eric.stevens@sum.co.nz> wrote:
>>
>> >On Mon, 08 Nov 2004 22:27:35 +0100, Erik Hammerstad
>> ><egeha.is.all.you.need@start.no> wrote:
>> >
>> >>Eric Stevens wrote:
>> >>> On 8 Nov 2004 11:06:16 -0800, david_christainsen@hotmail.com (David
>> >>> Christainsen) wrote:
>> >>>
>> >>>
>> >>>>Dear friends,
>> >>>>
>> >>>>Antarctic Forests Reveal Ancient Trees
>> >>>>http://dsc.discovery.com/news/briefs/20041101/leaves.html
>
>[..]
>
>> >>260 MA ago Antarctica was at the pole, see for example Van Andel,
>> >>"New Views on an Old Planet", Cambridge 1985 (page 108 in my
>> >>copy). A comprehensive set of animations can be found at
>> >>http://www.scotese.com/ - your animation starts too late.
>> >
>> >For the time being I'm happy to take your word for it. My recollection
>> >of antarctica's movements is obviouly faulty.
>>
>> I have now managed to undertake a little research. The best site I
>> have found is http://jan.ucc.nau.edu/~rcb7/paleogeographic.html (which
>> is a link from http://www4.nau.edu/geology/ ). If one starts by
>> clicking on the 'Missisipian' link and then, one at a time, on down
>> the page you can see the continents dance for you.
>>
>> You are quite correct: the Antarctic was more or less where it is now
>> in the Permian period. The only problem is that the series shows that
>> it was covered by ice at that time and had been for a good many
>> million years previously. Only when one moves on past the Permian to
>> the Triassic does one come across an ice-free era. I have to ask how
>> it was that trees could grow in a permanently ice-bound Permian
>> Antarctic. Not this matters much in an archaeological news group.
>>
>> --- snip ---
>
>Note subject line: "260-Million..." and a ref to this being "Permian
>period" - if the situation is as defined below at 200 million years
>ago - then it cannot have been as either of you claim.
>
>http://www.exploratorium.edu/origins/antarctica/ideas/gondwana2.html
>http://earth.leeds.ac.uk/~greg/Gond.html
>http://www.nsf.gov/od/opp/support/gondwana.htm
>http://www.forestandbird.org.nz/magazines/98nov/gondwanaland.asp?
>http://www.historyoftheuniverse.com/gondwana.html
>
>There are any amount more references that indicate Antarctica was NOT
>where it is today at 260 Ma.
>
>Your ref:
>
>http://jan.ucc.nau.edu/~rcb7/Perm.jpg
>
>is out of date - the "Pangaea," theory from 1912 has been replaced by
>the Gondwanaland and Laurasia theory that is the current theory -
>since the 1960's.

The original article posted by David Christiansen claimed 250M years
ago:

http://dsc.discovery.com/news/briefs/20041101/leaves.html
  "Nov. 5, 2004 A quarter-billion years ago, forested islands
   flashed with autumnal hues near the South Pole a polar scene
   unlike any today, researchers say."

Most ot sites you have cited deal with conditions 50M years later.

Eric Stevens