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2008-09-08 – Enorme foresta fossile scoperta in Illinois, USA

Ancient trees recorded in mines

By Jonathan Amos
Science reporter, BBC News, Liverpool

Spectacular fossil forests have been found in the coal mines of Illinois by a US-UK team of researchers.

The group reported one discovery last year, but has since identified a further five examples.

The ancient vegetation – now turned to rock – is visible in the ceilings of mines covering thousands of hectares.

These were among the first forests to evolve on the planet, Dr Howard Falcon-Lang told the British Association Science Festival in Liverpool.

“These are the largest fossil forests found anywhere in the world at any point in geological time,” he told reporters.

“It is quite extraordinary to find a fossil landscape preserved over such a vast area; and we are talking about an area the size of (the British city of) Bristol.”

The forests grew just a few million years apart some 300 million years ago; and are now stacked one on top of another.

It appears the ancient land experienced repeated periods of subsidence and flooding which buried the forests in a vertical sequence.

They have since become visible because of the extensive mining operations in the border area between the states of Illinois, Indiana and Kentucky.

Coal seam (University of Bristol)
Scientists look up to see what would have been the forest floor

Once the coal seams have been removed (what were, essentially, the compacted soils of the forests), it is possible to go into the tunnels and look up at what would have been lying on the forest floors.

“It’s a really exciting experience to drive down into these mines; it’s pitch black,” the Bristol University research said.

“It’s kind of an odd view looking at a forest bottom-up. You can actually see upright tree stumps that are pointed vertically up above your head with the roots coming down; and adjacent to those tree stumps you see all the litter.

“We found 30m-long trunks that had fallen with their crowns perfectly preserved.”

Leaf (University of Bristol)
Some of the preservation is exquisite

The researchers believe their study of these ancient forests could give hints to how modern rainforests might react in a warmer world.

The six forests straddle a period in Earth history 306 million years ago that saw a rapid shift from an icehouse climate with big polar ice caps to a greenhouse climate in which the ice caps would have melted.

“The fascinating thing we’ve discovered is that the rainforests dramatically collapse approximately coincident with the greenhouse warming,” explained Dr Falcon-Lang.

“Long-lived forests dominated by giant club moss trees almost overnight (in a geological sense) are replaced by rather weedy fern vegetation.”

The next stage of the research is to try to refine the timings of events all those years ago, and work out the exact environmental conditions that existed. The thresholds that triggered the ancient collapse can then be compared with modern circumstances.

http://news.bbc.co.uk/1/hi/sci/tech/7604721.stm

additional links:

http://news.nationalgeographic.com/news/2008/09/080909-fossil-forest-illinois.html

 

Found after 300m years: rainforest fossils
Times Online – 9 set 2008
A series of fossilised forests the size of small cities have provided prehistoric evidence of how tropical rainforests are destroyed by global warming.
Midges provide huge window on past
Irish Times – 8 set 2008
FOSSILISED RAINFORESTS and the number of midge heads found in lake sediments are giving scientists important clues about how temperatures have changed
Ancient trees recorded in mines
BBC News – 8 set 2008
By Jonathan Amos Spectacular fossil forests have been found in the coal mines of Illinois by a US-UK team of researchers. The group reported one discovery
Earth ‘Was Affected By Global Warming 300myears Ago’
RedOrbit – 9 set 2008
GLOBAL warming was in action 300m years ago when it wiped out the planet’s first rainforests, scientists revealed today. Examination of “fossil forests”
Massive fossil forests found in Illinois
United Press International – 9 set 2008
LIVERPOOL, England, Sept. 10 (UPI) — Massive fossil forests dating back millions of years have been found in Illinois coal mines, a British researcher says
Scientists find tree fossils in Illinois
PRESS TV – 9 set 2008
Researchers have identified examples of fossil forests in the ceilings of the coalmines in the eastern state of Illinois in the US.
Ancient Forest Discovered in Mines
RedOrbit – 9 set 2008
Researchers from the US and the UK have found a fossil forest in the coal mines of Illinois. The team reported a similar discovery last year,
Fossilised forest found in Illinois coal mine
The Tech Herald – 8 set 2008
by Rich Bowden – Sep 8 2008, 23:05 The scientific team, led by Dr Howard Falcon-Lang of the University of Bristol, with colleagues from the Smithsonian
Our climate crisis 300m years ago
Metro – 8 set 2008
Global warming is far from a recent phenomenon – it devastated the Earth 300million years ago, scientists revealed. Climate change was behind the
Global warming wiped out the first rainforests
PhysOrg.com – 8 set 2008
Detail of a pteridosperm, an extinct seed-producing fern-like plant. Photo by Photo by Howard Falcon-Lang (PhysOrg.com) — Spectacular discoveries of fossil

settembre 20, 2008 - Posted by | America Northern, Multimedia, P - Paleobotanica, Paleontology / Paleontologia, Paleozoico | , , , , , , , ,

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