Unveiling the Mystery of Greenland's Ancient Plant Remains

[Andre]

Last decade ice core digging in the West Antlantic Ice Sheet (WAIS) gave a big surprise. Diatoms in the mud under the ice sheet revealed that there has been a sea bottom with a maximum age of some 500,000 years but possibly younger.

Pleistocene Collapse of the West Antarctic Ice Sheet
Reed P. Scherer, et al

Some glacial sediment samples recovered from beneath the West Antarctic ice sheet at ice stream B contain Quaternary diatoms and up to 108 atoms of beryllium-10 per gram. Other samples contain no Quaternary diatoms and only background levels of beryllium-10 (less than 106 atoms per gram). The occurrence of young diatoms and high concentrations of beryllium-10 beneath grounded ice indicates that the Ross Embayment was an open marine environment after a late Pleistocene collapse of the marine ice sheet.

http://www.sciencemag.org/cgi/content/full/281/5373/82

There was big commotion but apart from scary stories about sudden collapses of ice sheets the attention receded. Yet we are facing a formal "not understood" (science talk for mystery) phenonemon.

Guess what's under the Greenland ice sheet.

Grass and Trees!

Greenland ice core project yields probable ancient plant remains

A team of international researchers working on the North Greenland Ice Core Project recently recovered what appear to be plant remnants nearly two miles below the surface between the bottom of the glacial ice and the bedrock.

Researchers from the project, known as NGRIP, said particles found in clumps of reddish material recovered from the frozen, muddy ice in late July look like pine needles, bark or blades of grass. Thought to date to several million years ago before the last ice age during the Pleistocene epoch smothered Greenland, the material will be analyzed in several laboratories, said researchers.

The suspected plant material under about 10,400 feet of ice indicates the Greenland Ice Sheet "formed very fast," said NGRIP project leader Dorthe Dahl-Jensen, a professor at the University of Copenhagen's Niels Bohr Institute. "There is a big possibility that this material is several million years old -- from a time when trees covered Greenland," she said.

"Several of the pieces look very much like blades of grass or pine needles," said University of Colorado at Boulder geological sciences Professor James White, a NGRIP principal investigator. "If confirmed, this will be the first organic material ever recovered from a deep ice-core drilling project," said White, also a fellow of CU-Boulder's Institute of Arctic and Alpine Research.

http://www.glaciology.gfy.ku.dk/ngrip/index_eng.htm

I hope that they can date the sample roughly as carbon dating only goes to about 45,000 years. I think it will be a next surpsrise I doubt that these samples are older than half a million year.

Strange that millions of years is automatically assumed because of the "counter intuitive" estimate for younger years, although this would probably yield a world record. Mineralization (fossilization) of small objects can be done in weeks in the right circumstances. These samples seem not to be fossilized. (http://home.entouch.net/dmd/fossilization.htm It's the question if sub freezing temperatures stop the process completely for millions of years.

It may be as young as the last interglacial, the Eemian, 130,000 years ago. Then it would be a nice smoking gun for my little pet idea.

 

[Rader]

Greenland is covered by a cap of ice so deep, that perhaps will never melt. Norway while situated at the same latitude has a summer and rich vegetation. The gulf streem currents warms scandanavia and the rest of Europe.

Professor Hans Petersen, while researching the depts of the Equatorial Atlantic, at depths of 3,219 meters, the Swiss Albatross, discovered fresh water plants.

http://www.fuhrmann-hilbrecht.de/Heinz/geology/HH1996/menardii.html
http://www.agu.org/pubs/crossref/2004/2000PA000604.shtml

There are small marine animals, named forminiforos of two priniple generos, Globorotalia menardii and Globorotalia truncatulinoides. The first being caracterized by its shell that spirals in clockwise direction and inhabits warm waters, while the latter in clockwise direction and cold waters. The warm water type never appears above a line that extends from the Azores to the Canary Islands. While the cold water type dominates the cuadrilateral Northwest Atlantic. The middle Atlantic between Africa and South America, is abundantly populated with the warm type. Notwithstanding the cold type makes its aparition in the Equatorial Atlantic. and the warm type pentrates a barrior in direction east. Where is the barrier?
http://www.gomr.mms.gov/homepg/whatsnew/papers/biochart.pdf

 

[Andre]

Thanks for those links Rader,

The behavior of isotopes of diatoms and planctonic and benthic foraminifera is intensely studied in the ODP-sediment cores indeed. But the results are often puzzling like this example. Ca/mg and Ca/Sr ratios are other attempts for interpretation as paleo thermometers. Right here we see the discussion about it.

Greenland is covered by a cap of ice so deep, that perhaps will never melt

And why Greenland indeed? Why not the North West Territories. There as been a lot of ice in Canada (the Laurentide ice sheet) early in the last glaciation cycle. It started to melt before the onset of the Last Glacial Maximum (22,000 - 18,000) even before the LGM Eurasian (Weichselian) ice sheet reached its eastermost extent, the Kara sea N of Russia, stopping short of the Taimyr Peninsula.

Nowadays, all that ice surrounding Greenland has melted. Why not the centre-most ice of Greenland itself? On the contrary, the ice sheet of Greenland really started to grow like crazy, after the ice age, the Holocene. Incidentely the Kilimanjaro glaciers also came into being after the ice age in the same period.

It looks that the "ice age" was not so much about temperatures at all. I would say a global moistening event instead of a global warming event.

 

[Rader]

And why Greenland indeed?
I would say a global moistening event instead of a global warming event.

Hmmm now take a look at the link and maps. It seems some interesting things are happening over Greenland when the highs and lows change during droughts and rain season and summer and winter.
http://geosci.uchicago.edu/~gidon/papers/med/med2.pdf

and
http://t3.preservice.org/T0211464/climate.htm